,transcriber's note3 ,text enclosed by underscores is in italics 7italics74 ,page numbers enclosed by curly braces 7example3 #be7 have been incorporated to facilitate the use of the ,index4 ,images of the original pages are available through ,internet ,archive4 ,see https3_/_/archive4org_/details_/diatomac eofphi#jj;boye 99 99 99 99 99 ,illustration3 ,,duck ,,pond1 ,,corner ,,of ,,fourth ,,and ,,market ,,streets 7,,about #agjj7 ,,the ,,diatomace ,,of ,,philadelphia ,,and ,,vicinity ,,by ,,charles ,s4 ,,boyer1 ,a4,m41 ,f4,r4,m4,s4 ,,illustrated ,,with ,,seven ,,hundred ,,drawings ,,by ,,the ,,author ,,press ,,of ,j4 ,b4 ,,lippincott ,,company ,,east ,,washington ,,square ,,philadelphia #aiaf ,,preface ,the present contribution to the local flora is intended as an introduction to more extended research4 ,the study is of advantage in relation to the life history of aquatic animals1 the determination of ocean currents1 as proved by polar discoveries1 the investigation of geological strata where other fossil forms are absent1 and the analysis of water supply2 and1 when we consider the universal distribution of diatomace in the earth1 the water and even in the air and the enormous deposits formed in past ages and still forming1 we are able to realize the importance of a knowledge of these complicated forms and their function of purification4 ,the absence of descriptive works of reference in available form in this country1 the polyglot confusion of authorities abroad and the amount of time1 patience and skill required in obtaining1 preparing and examining specimens1 render the study one of difficulty4 ,the bibliography is omitted1 as it is understood by those who possess the works of reference1 and but few synonyms are given1 having but little1 except historical1 value1 especially when it is considered that modern investigators have no access to many of the earlier collections1 when any of these exist4 ,so far as the marine forms are concerned1 it is probable that nearly all occurring north of ,florida are here included1 and the fresh-water species described represent a large proportion of those found east of the ,alleghanies4 ,all of the figures are drawn to the same scale1 a magnification of eight hundred diameters1 from specimens in my possession1 nearly all of which were found in or near ,philadelphia4 ,if the work is of any value in inducing further investigation1 ,i hope1 in the words of ,julien ,deby1 that those who follow my advice will find in the study of these wonderful little organisms as much pleasure as ,i myself have found4 ,,the ,,author4 #e;,,introduction ,the ,delaware ,river rises in the ,western ,catskill ,mountains1 flows southward for about three hundred and seventy-five miles1 and expands into ,delaware ,bay about sixty miles from the sea4 ,its origin is among the ,devonian and ,carboniferous rocks1 and in its course it passes through ,silurian1 ,triassic and ,cretaceous formations1 finally reaching the ,cambrian and ,laurentian beds4 ,it also drains regions of the glacial drift and beds which overlie overturned ,miocene strata1 and are sometimes mixed with them4 ,from the mountains1 nearly four thousand feet high1 to the ,bay1 where the depth of water is not greater than seventy-five feet1 the diatomaceous flora1 from ,alpine cascades to the salt marshes of ,new ,jersey1 contains a larger number of species than any other equal portion of the ,american coast4 ,the city of ,philadelphia1 about one hundred miles from the sea1 lies at the junction of the ,schuylkill with the ,delaware1 and much of the land near the rivers1 especially southward1 is flat and low1 composed of recent alluvial deposits4 ,in the central districts the ground is high1 the deep sub-soil being mostly a dry gravel resting upon gneiss and schist1 although it is in part composed of a bluish clay which was probably laid down in the bed of the ancient river before the last period of the glacial drift4 ,the blue clay was not all deposited at the same time1 as in the lower strata many marine forms are found which do not occur in the upper layers4 ,this is notably the case in a deposit obtained at ,spreckel's ,sugar ,refinery and also at the east end of ,walnut ,street ,bridge1 where a layer of blue clay occurs which is overlain by glacial drift4 ,in other parts of the city mixtures of blue clay with more recent deposits are found1 including fresh-water forms from numerous creeks and rivulets which traversed what is now the city proper1 and especially from the vicinity of ,fourth and ,market ,streets1 where there existed as late as the year #agjj a large pond known as the ,duck ,pond which was subject to tidal overflow from its outlet1 ,dock ,creek4 ,the river water at ,philadelphia is not noticeably brackish1 although the tide extends thirty miles above the city and1 before the building of ,fairmount ,dam1 to the ,falls of the ,schuylkill4 ,at certain times1 when the river is low1 the influx of tide water is sufficient to produce an abundance of brackish water diatoms at ,greenwich ,point4 ,the entire absence1 however1 at present1 of many of the marine forms obtained in dredgings in the ,delaware opposite the city1 as at ,smith's ,island1 now removed1 and in certain well borings at ,pavonia1 ,pensauken1 ,gloucester and other places in ,new ,jersey1 where the depth reached the old blue clay1 indicates conditions quite different from those now prevalent4 ,in the ,bay itself comparatively few living species are found1 at least in any abundance4 ,in the study of local forms which follows1 the district included may be considered as circumscribed by the circumference of a circle having a radius of one hundred miles from ,philadelphia1 containing the ,states of ,new ,jersey and ,delaware1 the southeastern part of #f,pennsylvania1 a portion of ,maryland on the south and extending eastward to ,new ,york ,bay and ,long ,island ,sound as far as ,new ,rochelle4 ,the greater number of fresh-water species described have been obtained from near the city along the ,darby1 ,crum1 ,ridley and ,brandywine ,creeks and from various places in ,new ,jersey1 including the ,pine ,barren region of the southern part of the ,state4 ,numerous collections have been made in the ,schuylkill and the various reservoirs and along the ,wissahickon1 where an ,alpine gorge in miniature of singular loveliness is to be found within the limits of a city4 ,the fossil deposits are from well borings near ,camden1 ,n4 ,j41 and from excavations in various parts of the city4 ,there appears to be no relation between the ,miocene beds of the eastern coast and the deposits here described1 all of which have been formed later than the glacial period or in an interval between two such periods4 ,apparently no diatoms grew during the glacial era1 at least in sufficient abundance to leave any perceptible traces of their existence4 ,an examination of glacial flour and clays from the ,catskills shows an entire absence of these forms1 and ,i have never found them in the milky flow from the glaciers of the ,alps nor in the constantly muddy streams in certain of our ,western ,states4 ,the opacity of the water produces the same result as the absence of light in the deep lakes of ,new ,england1 where diatoms are found only on the stalks or roots of water-plants near the shore1 while in shallow ponds1 such as the small lake near the summit of ,mt4 ,lafayette1 the growth is abundant4 ,certain species will grow wherever there are moisture1 light and heat1 but the greater number require the presence1 in small amounts1 of substances produced by the decay of animal and vegetable life4 ,an abundance of diatoms in fresh water is usually an indication of its potability1 while their entire absence in shallow water may be due to an excess of bacteria4 ,the specimens from which the drawings are made have been collected by the author for many years2 in addition to possessing an almost complete library on the subject1 he has had the advantage of examining material obtained by the late ,mr4 ,lewis ,woolman and numerous slides furnished by a number of friends1 including ,mr4 ,john ,a4 ,shulze1 ,mr4 ,frank ,j4 ,keeley and ,mr4 ,t4 ,chalkley ,palmer1 to whom ,i here take pleasure in expressing my thanks4 ,the difficulties of the study are well stated by ,agardh in the following extract from the preface to his ,systema ,algarum3 ,because1 indeed1 in this respect1 no one will wonder whether in the distinction of species and reference to synonyms we have1 perchance1 committed many errors4 ,they have occurred and are bound to occur1 partly from the fact that one is not permitted to see the original specimens of all authors2 partly1 because sometimes even the original specimens of these plants are erroneous2 partly1 because the figures and descriptions of authors are often lacking and imperfect4444 ,there is added the difficulty of the study itself of these plants1 their submerged habitat1 the minuteness of their structure1 the rarity of their fruit1 the change in the dried #gplant1 the impossibility of culture1 the fallacies of microscopical vision and the chaotic condition of ,algology itself to-day4 ,the words of ,agardh1 written in #ahbd1 are almost as true to-day4 ,the lack of authentic specimens1 which we hope will be remedied in time by the collections of the ,smithsonian ,institute1 numerous incorrectly labelled slides in amateur collections1 the imperfections of figures copied and recopied1 without regard to relative size or correct references1 and the confusion in the attempts to harmonize different descriptions1 deter the student at the outset4 ,the remaining difficulties mentioned by ,agardh add1 however1 to the remarkable interest these forms have always had1 since no increase in optical perfection of the microscope serves to lessen the mystery of their structure and mode of growth4 ,,classification ,the few species of diatoms first discovered were included by ,lyngbye1 ,dillwyn1 and others in the genus ,conferva4 ,in #ahbd1 the species1 increased to forty-eight1 were separated by ,agardh into eight genera distinguished partly by their mode of growth4 ,but little change was made until ,heiberg1 in #ahfc1 advocated the division into symmetrical and asymmetrical forms4 ,without entering upon a general review of the later classifications1 including ,pfitzer's and ,petit's divisions according to the number and location of the chromatophores1 or the arrangement of ,prof4 ,h4 ,l4 ,smith1 because of the presence or absence of a raphe1 or that of ,mereschkowsky into motile and immotile forms1 the modification of all of these methods by ,schuett is here adopted1 varied in accordance with certain monographs which appear to offer advantage4 ,it is customary1 especially among writers who are familiar with other classes of plants1 to decry any classification of diatoms according to the markings of their siliceous envelopes4 ,as1 however1 one of the chief distinctions of the class is the possession of a more or less siliceous and indestructible frustule1 and as the cell and its contents are never seen except within the valves1 their variety forms the only available method of identification4 ,the cell contents1 owing to the difficulty of observing their living condition1 their continued change1 their lack of distinct variation and their entire absence in fossil forms1 render their consideration as a complete method of classification an impossibility4 ,if1 however1 the cell contents can be brought into relation with the markings of their siliceous envelope1 it will be a consummation for which the future student of these complicated forms ought to be grateful4 ,that this result is one to be expected may be inferred from the fact that the arrangement of protoplasmic masses in the interior of the cell is coincident in some cases with markings on the valve1 and the character of the endochrome is assuming a certain value in accentuating the difference between such forms as ,pleurosigma and ,gyrosigma1 or in the resemblance between ,hantzschia and ,nitzschia1 or between ,surirella and ,campylodiscus4 ,mereschkowsky1 however1 states that it is necessary to be careful in establishing the relationship between diatoms based on the resemblance of their chromatophores1 #h;and further observes that in ,hantzschia amphioxys1 ,scoliotropis latestriata and ,achnanthes brevipes1 three widely separated forms1 the chromatophores are essentially the same4 ,in one of the earliest classifications of diatoms1 the individual cell received less consideration than the nature of the filament or thallus in which many species occur in the first stages of their growth4 ,those1 however1 which exist in colonies at first are1 sooner or later1 broken up into separate frustules1 either before or at the time of their maturity or previous to conjugation1 while very many species are never seen except in a free state4 ,the union of frustules1 therefore1 is of secondary importance and the group must be considered as filamentous or unicellular alg4 ,their relation to other alg is not well determined4 ,among the ,desmidiace1 a family of the order ,conjugales1 of the class ,chlorophyce1 the cells are in many forms divided by a constriction into symmetrical halves4 ,the ,conjugales are starch forming1 with walls of cellulose4 ,in the ,diatomace the starch is replaced by oil globules1 while the walls of cellulose are more or less filled with a deposit of silica4 ,the ,conjugales1 however1 reproduce by zygospores and usually contain pyrenoids1 as may be seen in the parietal chromatophores of ,spirogyra4 ,in the class ,heterokont we have the reserve material in the form of oil1 instead of starch1 but there are no pyrenoids4 ,to this class belongs the order ,confervace1 in which the cells are unicellular or filamentous1 and to which all of the ,diatomace were referred4 ,while1 therefore1 ,diatomace have a close affinity to the ,desmidiace and to the ,confervace1 the determination of their origin1 one from another1 or from a common ancestral type1 appears to be a matter of conjecture4 #i,,morphology ,,and ,,development ,,the ,,cell ,the cell membrane is composed of two usually equal parts1 each of which consists of a valve and a girdle or zone formed of cellulose modified by silica deposited in an insoluble state from a very dilute aqueous solution4 ,the valves are more siliceous and robust than the girdle4 ,both are in most species easily separable1 or at least the bands of the girdle which may be more or less closely fastened to the valves have a motion over each other permitting the cell to enlarge at pleasure4 ,the longitudinal diameter of the cell1 or the distance between the centres of the two valves1 will vary according to the convexity of the valve and the age of the frustule which may be often determined by the width or number of the girdle bands4 ,these1 owing to their diversity of form and arrangement1 will be further described under the generic diagnoses4 ,the siliceous cell-wall is covered on the outside by a layer of protoplasm called the coleoderm4 ,this layer may be quite thin and evident only when treated with fuchsin or ,bismarck brown1 or it may be of considerable thickness4 ,the cell contains the cytoplasma1 protoplasm1 cell-sap1 endochrome1 pyrenoids1 oil globules and nucleus1 together with certain other less understood bodies4 ,the ,cytoplasma is a thin skin of colorless plasma covering the entire inner surface of the cell4 ,it is invisible in the living cell but is evident in plasmolysis4 ,in long forms it is thickened at the ends and is condensed at the plasma bridge which frequently connects the two valves and divides the cell into two parts1 each containing more or less protoplasm surrounding the vacuole in which are found the cell-sap and certain granules4 ,in some forms1 as ,meloseira1 the cytoplasma includes the entire mass of protoplasm4 ,the ,endochrome is seen in the form of one or more bands or plates1 of a yellowish or brownish color1 on the inner side of the valves or connective zone1 or in granules or irregular masses1 more or less numerous1 on the inner walls1 or sometimes grouped near the centre4 ,it consists of a mixture of chlorophyll and diatomine which differ in their relative solubility in alcohol and in their spectroscopic analyses4 ,the color varies from green to a chocolate brown in proportion to the amount of diatomine4 ,so far as the function of the endochrome is concerned it does not appear to differ from that of ordinary chlorophyll1 absorbing1 under the influence of light1 the carbon1 and disengaging the oxygen of the carbonic anhydride in the water4 ,diatoms do not live in absolutely pure or non-arated water4 ,the individual plates or granules of the endochrome are called chromatophores4 ,their number and significance will be referred to in the description of genera4 ,,the ,,pyrenoids4--,in the chromatophores of many species are found colorless1 homogeneous bodies1 strongly refractive1 of various shapes1 usually lenticular or fusiform1 which are known as ,pyrenoids 7,schmitz74 ,they are scarcely evident in the living cell1 but are distinguished by the action of hmatoxylin and other reagents4 ,flat forms occur in ,surirella and ,pleurosigma1 lens forms in ,pinnularia1 ,stauroneis1 ,synedra1 ,fragilaria and ,nitzschia1 while a spherical form is found in ,cymbella cuspidata4 ,the pyrenoids are always imbedded in the chromatophore4 ,their growth is by division4 ,schmitz considers them a part of the living chromatophore1 and their substance as working material which in excess has become resolved into the nature of a crystal which its form sometimes resembles4 ,comparisons are made between them and crystalloids found in certain monocotyledons4 ,the pyrenoid is evidently concerned in the formation of the chromatophore1 or in its division4 ,much of the conjecture1 however1 is due to the behavior of pyrenoids in other plants4 #aj,,oil ,,globules4--,it has been established by ,pfitzer that starch and sugar1 as assimilation products1 are replaced by oil in the cells of diatoms 7da bekannlich ,staerke und ,zucker bei den ,bacillariaceen nicht nachzuweisen sind74 ,the oil drops are more or less numerous1 of various sizes1 and are found in the cytoplasma1 the cell-sap1 and sometimes the chromatophores4 ,mereschkowsky describes certain globules as eloplasts1 which he divides into four kinds according to their number and position4 ,whether all of these are oil globules is a question not yet determined4 ,other bodies1 known as ,buetschli granules1 or volutin1 and described as little blisters filled with a tolerably robust refractive substance1 are considered by ,lauterborn to be a nitrogen reserve store4 ,they are found in the cytoplasma1 or in the cell-sap1 and can be fixed in picric acid and stained in methylene blue4 ,,note4--,for a discussion of the morphology of diatoms and a valuable rsum of the investigations of ,buetschli1 ,karsten1 ,lauterborn1 ,mereschkowsky1 ,mueller1 ,pfitzer1 ,schuett1 and others1 the student is referred to ,der ,bau der ,diatomzelle1 by ,dr4 ,otto ,heinzerling1 in ,bibliotheca ,botanica1 #aijh4 ,,cell ,,division ,the growth of diatoms follows the usual method of cell division as described by ,sachs 7,text ,book of ,botany1 #bnd ed41 p4 #af73 ,the nucleus of a cell which is about to divide becomes broader1 assuming the form of a biconcave lens1 and its nucleolus breaks up into irregular granules which together with its other granular contents begin to form a nuclear disc in the equatorial plane4 ,a delicate striation is now apparent in what is becoming the long axis of the nucleus1 at right angles to the nuclear disc1 and the characteristic nuclear spindle is gradually produced4 ,the nuclear disc splits into two halves lying side by side1 each of which travels to the corresponding pole of the nucleus2 thus two nuclei are constituted which are connected by fibrill4 ,the cell-wall and the chromatophore bands divide1 each nucleus passes to the centre1 and two new cells are formed4 ,in the meantime1 to permit of this division1 the two siliceous valves separate1 the girdle bands slipping over each other1 and opposite the larger or enclosing valve a new valve is formed1 the girdle band of which is seen later within the girdle of the mother valve4 ,opposite the smaller valve of the original cell and adjoining the new valve1 another valve is formed which also produces a girdle within the girdle of the smaller valve4 ,as a result of division we have1 therefore1 the valves of the original1 or mother cell1 the two new valves and four girdle bands4 7,pl4 #dj1 ,figs4 #ah and #ai47 ,in the process of division1 the continual formation of new valves1 enclosed in the older girdle bands1 will naturally cause a reduction in the size of the frustule4 ,while this reduction1 owing to the elasticity of the girdle1 does not always occur1 ,i believe1 yet1 in most cases1 the diameter is so reduced that a rejuvenescence of growth is required4 ,this is caused by the production of auxospores which may appear without conjugation4 ,in this process1 the beginning of which1 in certain species1 may be noticed by the increase in the size of the girdle as in reduplication1 the two valves separate and within is formed a more or less spherical mass about twice the size of the original frustule and which forms on its circumference two large and often shapeless valves4 ,these valves form others which assume the appearance of the original valves1 but larger1 and proceed to grow in the usual way4 ,the reduction in size of the frustule seldom proceeds further than about half the size of the type form1 so that1 as a general rule1 it may be stated that diatoms are not often smaller than half the larger size4 ,,reproduction ,the process of reproduction has been observed in many cases1 but the conclusions reached are somewhat at variance with each other4 ,the auxospore formation is simply a #aamethod of rejuvenescence4 ,when1 however1 the auxospores are thrown off from filamentous diatoms1 it is probable that two may conjugate1 their contents dividing each into two daughter cells which unite into two zygospores4 ,the usual method is the union of two frustules1 which1 throwing off the old valves1 coalesce into a single mass of protoplasm which produces an auxospore1 sometimes called a sporangial frustule4 ,it is stated that in some cases two frustules coalesce and produce two auxospores4 ,the existence of spores in diatoms is a much-disputed point4 ,while they have never been seen1 the inference that they exist is very great1 as otherwise it becomes difficult to understand the sudden growth of species in localities and under conditions that seem to preclude the actual presence of the living frustule4 ,it is a matter of common observation that1 in examining collections of living forms1 minute frustules or brownish globules appear to resemble larger diatoms4 ,in gatherings of ,gomphonema1 when many specimens are sessile on the same object1 numerous intermediate sizes1 varying from minute globules to the type1 are seen1 yet not positively demonstrable as the same4 ,conjugation1 the formation of auxospores1 and the actual process of cell division are seldom seen1 as they occur during the night or at least in darkness4 ,it is advisable in order to observe reduplication to obtain the material about midnight and place it in very dilute alcohol4 ,in filamentous forms1 however1 the cell division is easily observed at any time in its various stages4 ,by immersing in picric acid 7saturated solution71 transferring to very dilute alcohol which is gradually increased in strength1 and then passing through oil of cloves and finally to the mounting medium1 excellent preparations can be made4 ,by staining with gold chloride alone the nucleus is made apparent without further treatment4 ,,evolution ,,of ,,forms ,it may be assumed that diatoms originated in the sea2 to deny this requires evidence of the existence of fresh-water species previous to the ,miocene period which is entirely marine4 ,in those subject to fluctuations of the waves1 as pelagic diatoms1 their existence appears to be contingent upon the methods by which the separate frustules can cohere4 ,various devices1 including hooks1 spiral bundles1 horns and processes exuding threads of plasma1 exist for holding together the frustules4 ,when marine forms are found in quiet waters some of these devices1 being no longer of any value1 cease to grow1 although free swimming diatoms are rare4 ,they either occur in long chains or are stipitate or sessile4 ,if it is further assumed that the fresh-water diatoms are found in greater abundance in later periods1 the action of running streams makes necessary the provision of some means by which the species may continue to colonize4 ,this may be recognized in the occurrence of linear forms chiefly in streams4 ,circular forms1 such as ,cyclotella which have no raphe1 are found in quiet waters1 such as pools or ditches1 and never exist living in running streams4 ,those forms only would be able to live in water having a more or less swift current under one of three conditions3 they must1 as in ,gomphonema1 be adherent to surrounding objects by a stipe2 or be enclosed in a gelatinous tube1 as in ,homoeocladia2 or have an independent motion powerful enough to overcome the influence of the current4 ,it is true that many forms with a raphe have no apparent motion4 ,in the case of ,mastogloia provision is made in a gelatinous cushion in which the frustules are preserved4 ,in ,cocconeis1 with a true raphe in one valve only1 in ,epithemia1 with a partial raphe1 or in certain ,eunoti with a trace of one1 we find species evidently degenerate and parasitic4 ,the long ,synedr1 having only a median line1 live in running streams1 since they are attached at one end to other algae4 ,forms with a true raphe appear to be more highly developed1 since they are able to seek locations favorable to growth4 ,given1 therefore1 the structure of the valve1 the habitat may be inferred4 #ab,,the ,,motion ,,of ,,diatoms ,the erratic backward and forward movement of certain diatoms1 especially those of the ,naviculoid group1 or the slow1 rolling motion of ,surirella1 has been discussed in so many ways without definite conclusions that a brief statement will be sufficient4 ,osmosis1 the amoeboid movement of the coleoderm1 the protrusion of protoplasm or protoplasmic threads through the raphe1 the existence of actual organs of locomotion or cilia1 and the lack of synchronism in the chemical action occurring at the ends of the cell which is sometimes divided by the plasma bridge1 have been offered in explanation4 ,the chief objection to the theory of cyclosis appears to be that the resultant motion is so greatly in excess of the rotation of protoplasm in the cell4 ,more or less motion is observed in various kinds of free cells1 but the movement of diatoms is not evident in those without either a raphe or a keel upon which and apparently by which the phenomena are produced4 ,mr4 ,t4 ,chalkley ,palmer1 in various articles in the ,proceedings of the ,delaware ,county ,institute of ,science1 especially in ,vols4 #a and #c1 gives the results of exhaustive experiments4 ,nothing1 it would seem1 he says1 could be more conclusive as to the essential sameness of the nature of motion in monads and diatoms1 than the fact that both monads and diatoms require oxygen in order to perform motion1 that they come to rest when oxygen becomes scarce1 and that they resume their motion when oxygen is again supplied4 ,he also thinks that the living substance of the cell1 more or less deeply overlaid with coleoderm substance of varying consistency1 and itself assuming that degree of fluidity which best meets the requirements of the situation1 permeates the raphes1 circulates in the keels1 or in some cases protrudes quite beyond the silica1 and functions as the actual propulsive agent4 ,,the ,,function ,,of ,,diatoms ,of all forms of vegetation1 the ,diatomace are1 perhaps1 the most ubiquitous4 ,where-ever a sufficient amount of moisture1 heat and light are found1 they grow4 ,it was during the ,miocene period that they first appeared1 and1 as marine forms1 reached their greatest development1 both as to size and beauty of marking1 while their prevalence throughout the world in enormous quantities has been often mentioned4 ,the ,miocene beds of ,richmond and ,maryland continued over the ,cretaceous formations of ,new ,jersey have outcropped in certain localities within our district1 but are not considered in this discussion4 ,the function of diatoms is not essentially different from that of other alg in providing food for aquatic animals1 such as ,salp and oysters1 but it is1 however1 in other respects that they are not only important but necessary factors in the preservation of life4 ,full nature swarms with life2 one wondrous mass ,of animals1 or atoms organized1 ,waiting the vital breath1 when parent heaven ,shall bid his spirit blow4 ,the hoary fen1 ,in putrid streams1 emits the living cloud ,of pestilence4 ,thro' subterranean cells ,where searching sunbeams scarce can find a way1 ,earth animated heaves4 ,i am not certain if ,thomson fully understood the matter1 but he has remarkably described the facts4 ,when the vital breath of returning spring animates the earth1 the subterranean cells of diatoms1 the atoms organized1 through the liberation of vast quantities of oxygen1 immediately begin the purification of the putrid streams4 ,were these streams not so purified1 the accumulation of animal and vegetable dbris would eventually cause an enormous bacterial growth fatal to animal life4 #ac;,,diatomace ,unicellular or filamentous4 ,cells either free1 sessile1 united in filaments1 immersed in a gelatinous envelope or in fronds composed of branching tubes2 microscopic1 enclosed in a more or less siliceous envelope 7frustule71 composed of two parts 7valves71 usually connected by an intervening band 7zone or girdle74 ,cell contents include yellowish or brownish chlorophyll-like bodies which occur in one or several bands 7placcochromatic71 or as variously distributed granular masses 7coccochromatic7 lining the inner walls4 ,growth by ordinary cell division or by auxospores2 sexual multiplication by the formation of sporangia4 ,valves of two kinds3 7a7 ,those in which the markings or parts are more or less concentric 7,centric72 7b7 ,those 7,pennat7 in which the parts are more or less symmetrically divided by a line 7pseudoraphe7 or by a cleft 7raphe74 ,,centric ,valves without a dividing line or cleft2 markings more or less radiate2 transverse section of frustule circular1 polygonal1 or elliptical1 sometimes irregular4 ,divided into four groups3 #a4 ,discoide4--,frustules 7cells7 discoid2 valves without horns or elevations 7sometimes with processes74 #b4 ,solenoide4--,frustules with numerous girdle bands4 #c4 ,biddulphioide4--,frustules box-like1 i4 e41 with the longitudinal axis greater than in the ,discoide4 ,valves with two or more angles1 elevations or horns4 #d4 ,rutilarioide4--,valves as if naviculoid1 but with irregular or radial structure4 ,groups #b and #d are not included in our description4 ,no4 #b contains plankton genera only1 while ,no4 #d consists of genera not yet found in this locality4 ,,discoide #a4 ,coscinodisce4--,valve not divided by rays or cost into sectors2 puncta sometimes radiate2 ocelli or processes absent4 #b4 ,actinodisce4--,valve with radial stri divided into sectors3 ocelli and processes absent4 #c4 ,eupodisce4--,valve disc-shaped with mammiform processes or one or more ocelli4 #a4 ,,coscinodisce 7a7 ,meloseirin4--,frustules short1 in chains4 7b7 ,coscinodiscin4--,frustules disc form1 usually single1 rarely in short chains4 7a7 ,,meloseirin #a4 ,meloseira4--,valve punctate1 with a constriction or furrow between edge of valve and girdle4 #b4 ,gaillonella4--,valve punctate1 with a circular collar or crest near edge of valve4 #c4 ,lysigonium4--,valve punctate1 neither keeled nor constricted4 #d4 ,hyalodiscus4--,valve punctate in the centre2 border with decussating radial lines4 #e4 ,stephanopyxis4--,border of valve with a crown of thorns2 valve areolate4 #f4 ,pyxidicula4--,valve areolate1 with a border of spines4 #ad,,meloseira ,,ag4 7#ahbd71 em4 ,,de ,,toni 7#ahib7 7melos1 a limb or member1 and seira1 a chain7 ,frustules globose1 ellipsoidal or cylindrical1 concatenate1 closely joined together4 ,valve either simply punctate or punctate and areolate4 ,a constriction of the cell-wall1 forming a furrow between the edge of the valve and the girdle1 is more or less evident4 ,the genus ,meloseira constituted by ,agardh has been variously modified by ,kuetzing1 ,thwaites1 ,wm4 ,smith1 ,van ,heurck1 ,de ,toni1 and others4 ,in ,systema ,algarum ,agardh included certain species of ,conferva1 of ,lyngbye1 ,dillwyn and others1 and limited his genus to frustules more or less globose 7fila articulata ad genicula constricta71 although in his ,conspectus ,criticus 7p4 #fd71 he modifies the description 7fila teretia articulata1 articulis diametro qualibus vel longioribus7 to include ,m4 varians4 ,as1 however1 ,lysigonium ,link1 ,gaillonella ,bory1 and other genera enlarged by ,ehrenberg and ,kuetzing1 came to be included under ,meloseira1 ,thwaites suggested the division of the genus into two3 ,orthosira1 in which the frustules are not convex at the ends and ,aulacosira in which no central line is apparent but with two distinct sulci4 ,wm4 ,smith adopts the genus ,orthosira but rejects ,aulacosira1 including all forms under the former genus and ,meloseira1 suggesting that differences exist in the formation of the sporangia of the two genera4 ,m4 varians and ,m4 crenulata appear to form auxospores or sporangial frustules in different ways1 as will be noticed hereafter4 ,as1 however1 the present state of our knowledge is so limited and as much confusion would result in further changing the nomenclature1 ,i shall adopt1 for the most part1 the division made by ,de ,toni1 separating ,gaillonella and ,lysigonium and employing the name ,meloseira as emendated in ,sylloge ,algarum1 although1 as stated1 it omits the species of ,agardh4 ,that a further division may be necessary is indicated by the differences existing between the ,orthosira forms and the others4 ,,analysis ,,of ,,species ,frustules cylindrical and lengthened3 ,valves with two distinct furrows2 granules small distans ,valves with coarse granules granulata ,valves denticulate on the margin crenulata ,valves denticulate and constricted roeseana ,valves with row of large puncta on the girdle side undulata ,frustules cylindrical and compressed3 ,valves punctate and areolate sulcata ,the chromatophores consist of circular and compressed or irregular flat granules which lie along the wall of the cell4 ,,meloseira ,,distans 7,,ehr47 ,,kuetz4 ,frustules cylindrical1 slender1 with two furrows1 one on each side of the suture2 valve in zone view with fine puncta in longitudinal rows2 puncta in valve view scattered4 ,l4 #g-aj 4 ,meloseira nivalis ,wm4 ,sm4 ,coscinodiscus minor ,wm4 ,sm4 ,fresh water4 ,fossil in ,new ,england deposits4 ,pl4 #a1 ,figs4 #h and #i4 ,,note4--,in all species of ,meloseira1 as well as ,gaillonella and ,lysigonium1 the frustules are so closely coherent that when the filaments are broken entire frustules are less frequently found than a union of two valves of contiguous frustules4 #ae,,meloseira ,,granulata 7,,ehr47 ,,ralfs ,frustules cylindrical1 robust1 #e-ah in diam41 with large granules in longitudinal1 sometimes spiral1 lines1 variable in size and arrangement in the same filament4 ,valve in valve view with scattered puncta4 ,variable in relative width and length1 passing to ,m4 crenulata4 ,gaillonella granulata ,ehr4 ,orthosira punctata ,wm4 ,sm4 ,fresh water4 ,fossil at ,coldspring1 ,l4 ,i4 ,pl4 #a1 ,fig4 #aj4 ,,meloseira ,,crenulata 7,,ehr47 ,,kuetz4 ,frustules cylindrical1 with furrows on each side of the suture1 #aj-bj in diam42 puncta in longitudinal rows4 ,margins of valves denticulate at the junction of the frustules2 valves with puncta scattered at the centre1 radiate at the circumference4 ,common in fresh water2 quite variable in size4 ,gaillonella crenulata ,ehr4 ,orthosira orichalcea ,wm4 ,sm4 in part2 not ,conferva orichalcea4 ,mertens or ,gaillonella aurichalcea ,ehr4 and ,bailey4 ,pl4 #a1 ,figs4 #a and #b4 ,,meloseira ,,roeseana ,,rab4 ,frustules cylindrical1 constricted toward each end1 with coarse1 longitudinal stri2 valve convex1 stri punctate1 radiating1 with several large granules at the centre4 ,connective zone with longitudinal rows of fine puncta4 ,diam4 #ab-de 4 ,orthosira spinosa ,grev4 ,fresh water4 ,media1 ,pa4 7,palmer72 not common4 ,pl4 #a1 ,figs4 #e and #f4 ,,meloseira ,,roeseana ,,var4 ,,epidendron 7,,ehr47 ,,grun4 ,frustules denticulate at the margin2 valve with coarse granules at the centre from which radiate lines of fine puncta4 ,wet rocks of the ,wissahickon4 ,pl4 #a1 ,figs4 #c and #d4 ,,meloseira ,,undulata 7,,ehr47 ,,kuetz4 ,frustules single or in twos1 usually broader than long1 constricted near the margin4 ,valve with six to twelve internal projections forming with the outline of the constriction of the valve a polygonal figure within the circumference4 ,surface of the valve with radiating lines of puncta disappearing toward the centre1 at which are numerous coarse puncta4 ,meloseira gowenii ,a4 ,schmidt4 ,blue clay of ,philadelphia1 especially common at ,twelfth and ,market ,sts4 ,pl4 #a1 ,figs4 #ae1 #af1 #ag4 ,,meloseira ,,sulcata ,,kuetz4 ,frustules quite robust1 with diam4 several times the length1 deeply furrowed at the margin1 areolate and punctate4 ,valve with radiating stri disappearing toward the centre1 and with a double row of cells near the margin1 the outer one having the appearance of a crown of teeth4 ,gaillonella sulcata ,ehr4 ,paralia sulcata 7,ehr47 ,cleve4 ,paralia marina ,heib4 #af,marine and brackish4 ,common in all parts of the world1 and fossil in the ,miocene4 ,the ,philadelphia form is the var4 genuina ,grun4 ,pl4 #a1 ,figs4 #aa and #ab4 ,in a gathering from ,media of ,meloseira crenulata 7,palmer leg471 occasional filaments are noticed with much longer and narrower frustules which become enlarged in the middle and are seen to contain inner frustules in the process of still further division1 as shown in ,fig4 #b1 ,pl4 #ch4 ,meloseira dickei ,thwaites shows internal box-like cells placed one within the other1 which were supposed by ,thwaites to be a method of reproduction4 ,wm4 ,smith doubts this1 but is unable to offer any explanation4 ,in the present form the mode of reduplication is that usually found in filamentous forms1 but in this case the presence of perfect frustules enclosing others in the process of still further division has been heretofore unfamiliar to me4 ,the swelling in the middle appears to indicate that not all filamentous diatoms are reduced in size by subdivision4 ,in outline the valve is like that of a truncated cone1 as described by ,petit in referring to ,gaillonella granulata var4 bambusina ,petit 7,diat4 ,nouv4 et ,rares1 ,jour4 de ,micrographie1 #ahij74 ,,gaillonella ,,bory ,,de ,,st4 ,,vincent 7#ahbc7 7named after ,gaillon1 a botanist of ,dieppe7 ,frustules ellipsoidal1 united in long filaments1 usually found in pairs2 each valve is furnished with a circular collar or crest extending at right angles to the convex edge4 ,valve hyaline at the centre from near which radiate lines of fine puncta1 #ah-bj in #aj 4 ,,note4--,the original names of both ,meloseira and ,gaillonella are retained1 as there is no good reason for contracting the ,greek diphthong in the first1 and the second is the correct spelling4 ,,gaillonella ,,nummuloides 7,,dillw47 ,,bory ,frustules as in the generic diagnosis4 ,diam4 #cj 4 ,conferva nummuloides ,dillwyn 7,brit4 ,conferv1 p4 #de1 ,sup4 ,pl4 ,b74 ,meloseira nummuloides ,ag4 ,heiberg and ,o',meara assign this species to ,lysigonium moniliforme 7,muell47 ,link1 which is not keeled4 ,while ,dillwyn's and ,lyngbye's figures do not show the keel1 it is probable from their descriptions that the angular outline produced by the keel was noticed4 ,marine or brackish4 ,coast of ,new ,jersey2 ,hudson ,river 7,bail474 ,pl4 #a1 ,figs4 #ac and #ad4 ,gaillonella moniliformis of ,bailey is this form1 as he describes it as having two minute projections of the delicate transverse ridges seen near the ends of the two globules belonging to a joint4 7,amer4 ,jour4 ,science1 #ahdb1 p4 #hi1 ,pl4 #b1 ,fig4 #c47 ,,lysigonium ,,link 7#ahbj7 7luo1 to loose1 and gonu1 a joint7 ,frustules globose1 concatenate2 valve simply punctate4 ,,lysigonium ,,moniliforme 7,,muell47 ,,link ,frustules usually in twos1 not keeled2 valve with puncta in longitudinal lines1 the puncta of the enveloping zone larger and in transverse rows4 ,l4 #be-dj 7,de ,toni74 ,conferva moniliformis ,mueller 7#aghc74 #ag;,conferva nummuloides ,eng4 ,bot4 pl41 #bbhg1 not ,dillwyn4 ,meloseira borreri ,grev4 ,lysigonium nummuloides 7,lyngb41 ,kuetz47 ,o',meara ,gaillonella nummuloides 7,dillw47 ,bory4 ,see ,o',meara1 p4 #bdh4 ,marine and brackish4 ,long ,island ,sound and coast of ,new ,jersey4 ,pl4 #a1 ,fig4 #g4 ,,lysigonium ,,varians 7,,ag47 ,,de ,,toni ,frustules cylindrical1 in long filaments1 slightly constricted on each side of the suture2 puncta in oblique rows in zone view4 ,valves #ae-ce in diam4 7,de ,toni71 sub-plane1 with fine puncta in lines radiating from the centre4 ,under medium magnification the frustules appear smooth4 ,very variable in size4 ,meloseira varians ,ag4 ,fresh water4 ,common in ditches and springs4 ,pl4 #a1 ,figs4 #ah and #ai4 ,,hyalodiscus ,,ehr4 7#ahde7 7hyalos1 transparent1 and discus1 a disc7 ,frustules spheroidal2 valve with a flattened1 irregularly punctate umbilicus from which proceed radiating or decussating lines of fine puncta4 ,,analysis ,,of ,,species ,valves divided into sectors stelliger ,valves not divided but interrupted by short dark lines at intervals radiatus ,valves with very fine puncta scoticus ,,hyalodiscus ,,stelliger ,,bail4 ,valve with puncta in oblique decussating rows which1 by reason of the difference in obliquity1 form numerous sectors4 ,umbilicus irregular1 with scattered1 coarse puncta4 ,margin wide1 striated4 ,podosira maculata ,wm4 ,sm4 ,blue clay4 ,not common4 ,pl4 #a1 ,fig4 #bb4 ,,hyalodiscus ,,radiatus ,,var4 ,,arctica ,,grun4 ,valve with radiating puncta from a rather small umbilicus1 the rays interspersed with short1 dark lines1 having the appearance of spines1 at irregular intervals4 ,margin broad1 striated4 ,pyxidicula radiata ,o',meara4 ,the ,philadelphia form corresponds exactly to ,grunow's variety which has closer puncta than the type form4 ,blue clay4 ,rather rare4 ,pl4 #a1 ,fig4 #ba4 #ah;,,hyalodiscus ,,scoticus 7,,kuetz47 ,,grun4 ,valve small1 with puncta about #bd in #aj 1 appearing hyaline4 ,de ,toni remarks that it resembles a small form of ,h4 subtilis which occurs north and south of our limits and is yet likely to be recorded4 ,cyclotella scotica ,kuetz4 ,podosira hormoides ,wm4 ,sm4 ,blue clay4 ,not rare4 ,pl4 #a1 ,fig4 #bj4 ,endochrome in the form of four flaps or patches bound together about a common pyrenoid4 ,in ,h4 subtilis numerous rod-shaped chromatophores lie in a row and are not bound in the centre 7,mereschkowsky74 ,,stephanopyxis ,,ehr4 7#ahdd7 em4 ,,grun4 7#ahhd7 7stephanos1 a crown1 and pyxis1 a kind of vase or box7 ,frustules ellipsoidal1 concatenate2 valves tumid1 of unequal convexity1 coarsely areolate1 the cells in rows parallel to the longitudinal axis1 not radiate1 with stray spines or teeth placed concentrically more or less near the margin4 ,according to ,karsten the chromatophores are round or angular discs which lie near the connective zone4 ,,stephanopyxis ,,turris 7,,grev47 ,,ralfs ,valve cylindrical1 with a crown of stout spines less than the diameter of the valve near the margin4 ,cells hexagonal1 about #b in #aj 1 sometimes punctate4 ,the valve having the greater convexity has the larger spines1 though usually less of them4 ,creswellia turris ,grev4 7,gregory1 ,diat4 of the ,clyde1 ,t4 ,r4 ,s4 ,e41 vol4 #ba1 part #d1 p4 #ff47 ,stephanopyxis appendiculata ,ehr48 ,creswellia is incorrectly based1 as stated by ,ralfs1 on the concatenation of the valves which was not noticed by ,ehrenberg in the fossil forms4 ,it had been suggested by ,kuetzing in ,systema ,algarum 7p4 #abf74 ,blue clay4 ,port ,penn and ,smith's ,island4 ,pl4 #b1 ,figs4 #a and #b4 ,,stephanopyxis ,,corona 7,,ehr47 ,,grun4 ,valve larger than in turris1 sub-globose1 coarsely areolate cells1 #d-e in #aj 4 ,one valve furnished with a crown of teeth shaped like the letter ,t and united at the top into a ring above the margin of the valve2 the other valve with long spines more or less concentrically arranged4 ,blue clay4 ,not common4 ,fossil in the ,nottingham deposit4 ,pl4 #b1 ,fig4 #c4 ,,note4--,the diatomaceous deposit1 so often called ,bermuda or ,bermuda tripoli1 especially by foreign writers1 is in reality the ,miocene stratum extending for miles along the ,patuxent ,river near the village of ,nottingham1 ,md4 ,the author is perfectly familiar with the location1 having made large collections there4 ,the mistake in the name is due to the fact that ,prof4 ,bailey received material from ,mr4 ,tuomey marked ,bermuda ,hundred1 which is located near ,petersburg1 ,va4 ,attempts have been made to find material there and while there is an earth containing ,miocene diatoms at ,petersburg1 it does not exactly correspond to the material sent to ,ehrenberg by ,bailey1 who was in doubt as to the locality4 ,the ,bermuda ,islands are of coral formation and have no deposits of diatomaceous earth4 #ai,,pyxidicula ,,ehr4 7#ahcc7 7dim4 of pyxis1 a box7 ,frustules globular1 solitary or in short fasci4 ,valve more or less hemispherical1 areolate1 destitute of spines4 ,,pyxidicula ,,cruciata ,,ehr4 ,valve hemispherical1 with large1 hexagonal cells4 ,an inner stratum is finely punctate4 ,blue clay4 ,walnut ,st4 ,bridge4 ,rare4 ,pl4 #ch1 ,fig4 #h4 ,this form is not usually described as having punctate areol1 but it does not apparently differ from other forms of ,pyxidicula of ,ehrenberg as described by ,kuetzing 7,species ,algarum1 pp4 #ba-bc71 including ,p4 areolata4 ,in fact1 it differs from ,stephanopyxis1 which is also sometimes punctate1 only in the absence of spines4 ,in fossil deposits the absence of an easily detached stratum is not significant4 ,the difference1 except in size1 between it and ,p4 mediterranea ,grun4 7,v4 ,h4 ,s41 ,pl4 #ie1 ,figs4 #ae and #af71 ,i am unable to determine4 ,although many species of ,meloseira are fresh-water1 the habitat of the group ,meloseirin is1 in general1 marine4 ,it more nearly coincides in structure and development with other alg not diatomaceous1 the siliceous envelope constituting its most distinctive feature4 ,as we proceed in the classification1 the structure both of the frustule and contents becomes more complicated4 7b7 ,,coscinodiscin #a4 ,cyclotella4--,valve with two concentric divisions of different structure1 one a wide border and the other a central surface4 #b4 ,coscinodiscus4--,valve areolate or punctate1 with a narrow border of the same structure4 ,,cyclotella ,,kuetz4 7#ahcc7 7cyclos1 a circle7 ,frustules single or geminate1 cylindrical1 short1 in zone view rectangular or with undulating sides4 ,valve usually with smooth or punctate stri1 centre sometimes bullose1 smooth1 or with granules scattered or radiating4 ,chromatophores numerous along the valves 7,pfitzer74 ,,cyclotella ,,striata 7,,kuetz47 ,,grun4 ,valve #cj-hj in diam41 with coarse stri1 #g-ab in #aj 1 centre coarsely punctate and bullose4 ,coscinodiscus striatus ,kuetz4 ,cyclotella dallasiana ,wm4 ,sm4 ,common in the blue clay4 ,pl4 #b1 ,fig4 #i4 ,,cyclotella ,,meneghiniana ,,kuetz4 ,frustule in zone view rectangular1 undulated2 valve1 #aj-bj in diam41 marginal stri robust and transversely punctate1 centre radiately punctate4 ,cyclotella kuetzingiana ,wm4 ,sm4 7not ,thwaites74 ,crum ,creek4 ,pl4 #b1 ,fig4 #h4 #bj;,,cyclotella ,,meneghiniana1 ,,var4 ,,stelligera ,,cl4 ,,and ,,grun4 ,differs from the type in the coarse radiating lines at the centre4 ,broomall ,lake1 ,media4 ,pl4 #b1 ,fig4 #d4 ,,cyclotella ,,meneghiniana1 ,,var4 ,,stellulifera ,,cl4 ,,and ,,grun4 ,as in type but with the central rays granulate4 ,broomall ,lake1 ,media4 ,pl4 #b1 ,fig4 #ab4 ,,cyclotella ,,stylorum 7,,br487 ,v4 ,h4 ,margin striated1 the alternate stri thickened near the border1 producing an appearance of subquadrate cells4 ,centre faintly granulate1 the outer border of which is encircled by #aj-ab puncta1 each of which is surrounded by a small hyaline space4 ,blue clay4 ,rare4 ,van ,heurck gives this form doubtfully as a variety of striata1 while ,de ,toni makes it synonymous with it4 ,van ,heurck's figure is not that of ,brightwell1 but as the specimen above described is1 ,i believe1 exactly the same as ,van ,heurck's1 ,i retain his name4 ,pl4 #b1 ,fig4 #aj4 ,,cyclotella ,,comta 7,,ehr47 ,,kuetz4 ,valve with marginal stri well marked1 each third or fourth costa more robust than the others4 ,central part finely striated1 the stri punctate1 radiating4 ,fresh water4 ,pl4 #b1 ,fig4 #g4 ,the form here figured is probably the variety radiosa ,grun4 and is from a ,new ,england specimen4 ,it is quite likely to occur in this locality4 ,,cyclotella ,,operculata 7,,ag47 ,,kuetz4 ,frustules in zone view undulated4 ,angles rounded4 ,marginal cost alternating with minute spines2 centre nearly smooth1 depressed1 convex or flexuose4 ,fresh water4 ,pl4 #b1 ,figs4 #e and #f4 ,the figure is drawn from a specimen from ,boston1 ,mass41 ,h4 ,l4 ,smith ,type ,slide ,no4 #ajg1 marked equivalent to ,c4 minutula ,wm4 ,sm4 ,,cyclotella ,,antiqua ,,wm4 ,,sm4 ,marginal cost alternating with thick puncta2 centre finely granulate with subtriangular elevations4 ,frustules in zone view rectangular4 ,blue clay4 ,pl4 #b1 ,fig4 #aa4 ,the form corresponds to the original specimens of ,wm4 ,smith in the deposit of ,stavenger1 ,norway4 ,the genus ,cyclotella comprises about seventy specific names1 many of which may be referred to other genera1 while some of ,ehrenberg's are incapable of verification on account of the small size of the figures and the lack of sufficient description4 ,about half of the forms are marine4 ,the fresh-water species are usually found living in more or less stagnant water or in pools contaminated with drainage1 being an exception to the general rule that diatoms are more abundant in water free from deleterious matter4 #ba;,,coscinodiscus ,,ehr4 7#ahch7 7coscinon1 a sieve1 and discus7 ,frustules solitary1 cylindrical1 compressed2 valve circular or elliptical2 surface flat or sometimes convex near the border2 markings more or less angular1 radiating1 sometimes fasciculate2 border usually well defined4 ,central space1 if present1 hyaline1 sometimes surrounded with a rosette of large cells4 ,chromatophores round1 angular or irregular discs usually without pyrenoids 7,karsten74 ,rattray's classification is here followed1 so far as it refers to our species4 ,excentrici4--,valves circular2 central space absent2 markings angular1 in oblique1 decussating rows4 ,lineati4--,central space absent2 markings angular1 oblique decussating rows straight4 ,fasciculati4--,markings fasciculate1 or sometimes only near the border4 ,radiati4--,markings rounded or angular1 more or less radiate4 ,elaborati4--,valves elliptical1 markings rounded4 ,,excentrici ,,coscinodiscus ,,excentricus ,,ehr4 ,valve with a hyaline excentric space from which proceed1 usually in six directions1 rows of polygonal markings decreasing toward the narrow1 coarsely striated border1 the rows appearing convex toward the centre4 ,apiculi at unequal distances apart4 ,quite variable in size4 ,common in the blue clay and along the coast4 ,pl4 #b1 ,figs4 #ad and #bj4 ,fig4 #bj is probably var4 perpusilla ,grun4 7,diat4 ,fr4 ,jos4 ,l41 ,pl4 #d 7,d71 ,fig4 #g74 ,,lineati ,,coscinodiscus ,,lineatus ,,ehr4 ,valve circular1 markings hexagonal1 cells in parallel rows4 ,border narrow1 cellular4 ,blue clay and ,atlantic coast4 ,not common4 ,pl4 #c1 ,fig4 #h4 ,,fasciculati ,,coscinodiscus ,,nitidus ,,greg4 ,valve flat1 markings rounded1 distant1 radiate1 decreasing toward the border which is coarsely striate4 ,quite variable in size and in the distance between the markings4 ,blue clay and ,atlantic coast4 ,common4 ,pl4 #b1 ,fig4 #ah4 ,,coscinodiscus ,,nitidulus ,,grun4 ,valve usually not quite circular2 markings smaller than in nitidus and fasciculate near the border4 ,blue clay4 ,pl4 #b1 ,fig4 #ai4 ,various intermediate forms between nitidus and nitidulus occur4 ,,coscinodiscus ,,subtilis ,,ehr4 ,markings polygonal1 irregular at the centre1 but forming numerous fasciculi radiating #bbtoward the border1 the rows parallel to the central row of each fasciculus4 ,border narrow with fine stri2 apiculi often present between the fasciculi4 ,blue clay and along the coast4 ,very common in the water supply of ,philadelphia and ,camden1 where the diameter seldom exceeds #dj and the markings on the semi-radius are #aj in #aj 4 ,pl4 #b1 ,fig4 #ag4 ,,coscinodiscus ,,denarius ,,schmidt ,markings larger than in ,c4 subtilis1 equal1 forming usually ten fasciculi1 each beginning near the semi-radius and containing ten parallel rows of granules4 ,common in the blue clay and sparingly along the coast4 ,pl4 #b1 ,fig4 #ac4 ,forms are found intermediate between ,c4 subtilis and ,c4 denarius1 as shown in ,fig4 #ae4 ,,coscinodiscus ,,polyacanthus ,,grun4 ,markings angular1 #aj in #aj 1 decreasing toward the border1 fasciculate4 ,apiculi large1 twelve or more1 usually inserted at the middle of each fasciculus1 and extending into the interior of the cell4 ,the apiculi in outline resemble the heads of horse-shoe nails1 and are seen with difficulty except when the valve is examined from the inner side4 ,border narrow1 striated4 ,diam4 #gj 4 ,pensauken1 ,n4 ,j41 artesian well4 ,pl4 #ch1 ,fig4 #e4 ,rattray's description of ,c4 polyacanthus var4 intermedia ,grun41 from ,cape ,wankarema1 ,siberia1 gives the diam4 as #fj 1 and there are about #g markings by actual count in #aj in ,grunow's figure 7,diat4 ,fr4 ,jos4 ,land1 ,pl4 #c 7,c71 ,fig4 #be74 ,the apiculi are more numerous1 but there appears to be little doubt of the general similarity4 ,the ,philadelphia form is abundant in the ,pensauken well deposit at a depth of #cc ft4 ,the apiculi become quite distinct in slides stained with silver nitrate by ,mr4 ,f4 ,j4 ,keeley2 they are distinct from small apiculi sometimes evident between the fasciculi4 ,the specimens in the ,pensauken deposit are mingled with other forms which cannot be distinguished from ,c4 subtilis4 ,whether the two are identical1 ,i am unable to determine4 ,rattray 7,rev4 ,cos41 p4 #dg7 refers to ,h4 ,l4 ,smith's ,type ,slide ,no4 #ajj1 from rice-field mud1 ,savannah1 ,ga41 as ,c4 subtilis4 ,in ,smith's slide1 in my possession1 a number of the forms show faint outlines of the large apiculi and are otherwise exactly like ,c4 polyacanthus4 ,,radiati ,,coscinodiscus ,,velatus ,,ehr4 ,markings angular1 decreasing slightly toward the coarsely striated border1 covered with fine puncta4 ,blue clay4 ,pl4 #c1 ,fig4 #b4 ,,coscinodiscus ,,marginatus ,,ehr4 ,markings rounded1 large1 decreasing toward the broad border1 which is coarsely marked with distant stri4 ,the cells are punctate4 ,common in the blue clay4 ,pl4 #c1 ,fig4 #i4 ,in the fossil forms the puncta are not evident1 hence the species is usually described as not punctate4 #bc;,,coscinodiscus ,,radiatus ,,ehr4 ,markings polygonal1 slightly decreasing toward the border where they are much smaller2 border well marked1 striate4 ,quite variable in size4 ,common in the blue clay and along the coast4 ,pl4 #c1 ,fig4 #aa4 ,fig4 #a is probably a smaller form4 ,,coscinodiscus ,,subaulacodiscoidalis ,,rattr4 ,markings small1 decreasing toward the border in somewhat fasciculate rows4 ,about one-third the distance from the border are five 7,rattray finds six7 well-marked apiculi somewhat resembling those of ,aulacodiscus4 ,border narrow1 hyaline4 ,rare in the lower stratum of the blue clay4 ,pl4 #c1 ,fig4 #d4 ,,coscinodiscus ,,argus ,,ehr4 ,markings angular with central dots1 increasing from the centre toward the border1 where they are smaller4 ,blue clay4 ,pl4 #c1 ,fig4 #g 7a small form74 ,,coscinodiscus ,,biangulatus ,,schmidt ,central space and rosette absent1 markings large1 angular1 not punctate1 with large central papill1 decreasing toward the border4 ,border wide1 coarsely marked with rows of granules1 and with two indentations on the inner side distant from each other about two-thirds of the diameter4 ,blue clay4 ,pl4 #c1 ,fig4 #c4 ,distinguished from ,coscinodiscus asteromphalus var4 omphalantha ,grun41 which also has two constrictions1 by the absence of punctate markings4 ,,coscinodiscus ,,asteromphalus ,,ehr4 ,central space small1 surrounded by a rosette of large polygonal cells from which radiate hexagonal cells1 increasing about half way toward the border and then slightly decreasing4 ,cells punctate4 ,blue clay4 ,pl4 #b1 ,fig4 #af2 ,pl4 #dj1 ,fig4 #ab4 ,,coscinodiscus ,,asteromphalus ,,var4 ,,omphalantha 7,,ehr47 ,,grun4 ,central space absent1 rosette evident4 ,markings #b in #aj 1 somewhat smaller near the rosette and decreasing near the border1 which is constricted in two places1 as in ,c4 biangulatus4 ,blue clay4 ,pl4 #ch1 ,fig4 #aj4 ,,coscinodiscus ,,oculus-,,iridis ,,ehr4 ,central space and rosette distinct2 markings polygonal1 not punctate1 with large papill1 smaller near the rosette1 increasing toward the semi-radius1 and then decreasing to the striated border which is comparatively narrow4 ,blue clay and ,atlantic coast4 ,pl4 #c1 ,fig4 #aj4 #bd;,,elaborati ,,coscinodiscus ,,lewisianus ,,grev4 ,valves elliptical1 major axis a little more than twice the minor4 ,from a point1 usually near one side1 radiate rows of granules in lines nearly parallel to the major axis4 ,border broad1 with distinct stri4 ,great ,sedge ,island1 ,n4 ,j4 7artesian well71 and in outcrops later than the ,miocene1 where it is usually found4 ,pl4 #c1 ,fig4 #e4 #b4 ,,actinodisce ,,actinoptychin ,valves divided into sectors alternately elevated and depressed4 7#a7 ,actinoptychus4--,sectors plane4 7#b7 ,polymyxus4--,sectors convex4 ,,actinoptychus ,,ehr4 7#ahci7 em4 ,v4 ,h4 7#ahij7 7actis1 a ray1 and ptyx1 a fold7 ,frustule cylindrical1 less in length than the diameter1 in zone view undulated4 ,valve divided into six or more sectors alternately raised and depressed1 areolate and punctate1 varying in the alternate divisions4 ,the areolation is confined to the outer layer of the valve while the punctation is usually on an inner valve often found detached4 ,processes on the border1 three or more4 ,umbilicus circular or angular1 hyaline4 ,,analysis ,,of ,,species ,sectors1 six undulatus ,sectors1 eight or more1 cellular heliopelta ,sectors1 fourteen1 punctate vulgaris ,,actinoptychus ,,undulatus 7,,kuetz47 ,,ralfs ,valve areolate and punctate in quincunx1 divided into six equal sectors1 alternately elevated or depressed1 their areolations appearing different4 ,margin well defined4 ,umbilicus smooth1 hexagonal4 ,processes three1 sometimes six1 inserted within the margin of each alternate division4 ,very variable in size and appearance4 ,this is the ,actinocyclus of ,bailey1 figured and described in ,amer4 ,jour4 ,science1 #ahdb1 p4 #ic1 ,pl4 #b1 ,fig4 #aa1 but not named4 ,kuetzing describes and names it and refers to ,bailey4 ,actinoptychus omphalopelta ,ehr4 ,actinoptychus cellulosa ,ehr41 ,h4 ,l4 ,smith ,sp4 ,typ41 #chd4 ,quite common in marine and brackish water and in the blue clay4 ,pl4 #d1 ,figs4 #a1 #b1 #d and #f4 ,,actinoptychus ,,vulgaris ,,var4 ,,interrupta ,n4 ,,var4 ,valve with fourteen sectors1 the alternate ones divided by a smooth lanceolate space for about one-half the radius1 forming with the smooth1 circular umbilicus a seven pointed star4 ,the sectors thus divided have coarser puncta in quincunx than the other sectors1 ending in a smooth area near the margin1 and also larger black puncta scattered from the centre to the semi-radius4 ,near ,a4 vulgaris var4 neogradensis ,pant4 ,blue clay4 ,not common4 ,pl4 #d1 ,fig4 #e4 #be;,,actinoptychus ,,heliopelta ,,grun4 ,,var48 ,valve circular1 sectors1 eight1 umbilicus circular1 without rays2 border wide1 cellular1 with distinct rays4 ,inserted at a distance within the inner edge of the border are large processes1 one on each of four alternate sectors1 and two on each of the others4 ,the sectors are cellulate and punctate4 ,near ,a4 heliopelta var4 versicolor ,brun41 which1 however1 in the specimen in my collection from ,atlantic ,city 7artesian well71 has a greater number of processes and they are situated on the edge of the border4 ,outcrop at ,buckshutem1 ,n4 ,j4 ,rare4 ,pl4 #d1 ,fig4 #c4 ,it has been quite well determined1 ,i think1 that the typical forms of ,a4 heliopelta occur at the base of the ,miocene4 ,at ,rock ,hall1 ,md41 on the eastern shore of ,chesapeake ,bay1 at a depth of from #ba to #acj ft41 and at ,wildwood1 ,n4 ,j41 at a depth of from #gh to #agi ft41 diatomaceous beds occur considered by ,mr4 ,lewis ,woolman 7,geol4 ,surv4 of ,n4 ,j41 #ahih1 pp4 #aaf-aba7 as synchronous in age1 the former being deposited in the ,delaware ,river ,delta and the latter in the ,chesapeake in post-miocene times4 ,in each of these beds a small form of ,a4 heliopelta is rarely found4 ,the material at ,buckshutem is post-miocene1 and the form here figured shows a marked variation from the ,miocene species and a gradual approach toward ,a4 undulatus4 ,,polymyxus ,l4 ,w4 ,,bail4 7#ahee7 ,valve circular1 usually divided into fourteen sectors which are on the same plane at the centre1 but the alternate ones are elevated into mammillated projections terminated by small processes on the margin4 ,zone view rectangular with undulations subconical1 terminated by the processes4 ,,polymyxus ,,coronalis ,l4 ,w4 ,,bail4 ,central space hyaline1 rounded or slightly stellate1 from which radiate rows of fine puncta in quincunx1 shown in the figure only on the alternate elevations1 the depressed interspaces being out of focus4 ,the mammill are stated by ,bailey to vary from six to ten4 ,very rare in the blue clay 7,walnut ,st4 ,bridge74 ,occurs also in the ,wildwood deposit 7,bull4 ,torrey ,bot4 ,club1 #ahie1 p4 #bfa74 ,pl4 #d1 ,fig4 #g1 and ,pl4 #e1 ,fig4 #b4 #c4 ,,eupodisce ,aulacodiscin4--,valves with mammiform elevations near the border surmounted by nipple-like processes4 ,,aulacodiscus--,,the ,,only ,,genus ,,as ,,above ,eupodiscin4--,valves with ocelli4 7#a7 ,actinocyclus4--,valve with one small ocellus2 stri radial4 7#b7 ,eupodiscus4--,valve with one or more ocelli2 stri not radial4 7#c7 ,auliscus4--,valve with large1 elevated ocelli4 ,central area hyaline4 ,markings granular and costate4 7#d7 ,pseudauliscus4--,valve with radiating granules4 ,no central space4 #bf;,,aulacodiscus ,,ehr4 7#ahdd7 em4 ,,rattr4 7#ahhh7 7aulax1 a furrow1 and discus7 ,valve usually circular1 plane or with an elevated zone1 frequently inflated beneath the processes2 central space irregular or rounded1 sometimes absent2 markings granular1 radial1 sometimes in a reticulum4 ,the genus comprises more than one hundred species most of which are fossil1 and is represented in this locality by a single form1 ,a4 argus1 included by ,rattray in his section ,retiformes1 distinguished by the presence of a reticulum4 ,,aulacodiscus ,,argus 7,,ehr47 ,,schmidt ,frustule in zone view elliptical4 ,valve circular1 #abe-aij in diam41 closely covered with two kinds of markings1 one1 a mesh of large1 radiating1 angular cells1 the outer plate1 and the other1 radiating rows of circular granules with hyaline spaces intervening and closer near the border1 forming the inner plate which can occasionally be seen detached4 ,central space absent4 ,the walls of the angular cells are crossed with fine lines and are probably composed of granules compressed so closely as to produce partial opacity1 the depth of which depends in a measure not only on the superposition of the two plates1 but on the relative closeness and thickness of the cell-walls4 ,in a fully-developed specimen the effect is to produce more or less triangular cells containing three or four granules4 ,in some cases the opacity is so great as to render detail invisible4 ,in the figure the valve is supposed to be divided into three sectors1 illustrating at a the lower plate1 at c the combination of the upper and lower plates1 and in the other sector the cellular mesh of the upper plate4 ,processes1 usually three1 quite robust and inserted at from one-fourth to one-fifth the length of the radius from the border which is striated on the inner side4 ,a form with four processes is found in the lower blue clay4 ,tripodiscus argus ,ehr4 ,eupodiscus argus 7,ehr47 ,wm4 ,sm4 ,not uncommon in the blue clay4 ,pl4 #d1 ,fig4 #h4 ,,actinocyclus ,,ehr4 7#ahcg7 7actis1 a ray1 and cyclos7 ,valve circular or elliptical2 surface flat at the centre1 sloping toward the border4 ,central space usually evident1 rounded or irregular4 ,markings rounded1 granular1 punctiform1 in radial1 or nearly radial1 rows1 sometimes fasciculate4 ,a nodule1 more or less evident1 is found near the border which is usually striate4 ,chromatophores round discs or granules4 ,,analysis ,,of ,,species ,valve circular1 rows radial1 hyaline lines at the border barkleyi ,valve circular1 rows fasciculate moniliformis ,valve elliptical ellipticus ,the nodule is generally supposed to be a thickening of the cell-wall1 and1 in the opinion of ,rattray1 a projection outward1 but whether there may not be at the same time a slight inward protuberance is difficult to determine1 though1 as a rule1 he seems to think there is not4 #bg;,,actinocyclus ,,barkleyi ,,var4 ,,aggregata ,,rattr4 ,surface flat from centre to semi-radius4 ,central space irregular1 sometimes with a few scattered granules4 ,markings round with central dots distinct1 about #g at the centre1 decreasing in straight radial rows to #ab in #aj at the border1 where they form moniliform stri4 ,border narrow with stri about #af in #aj 4 ,hyaline interspaces at the origin of the shorter rows1 but not at equal intervals4 ,at the border1 linear hyaline spaces occur at somewhat irregular intervals between the moniliform stri owing to the termination of certain radial rows before they reach the circumference4 ,nodule small1 from one-seventh to one-fourth the radius from the border4 ,according to ,rattray the distinction between ,a4 ralfsii and ,a4 barkleyi is partly in the absence of the zone arrangement of the hyaline spaces in the latter1 and to the slight differences in the number of granules4 ,the variety aggregata differs from the type form of barkleyi mainly in the distance of the nodule from the border4 ,i have specimens from the blue clay material at ,walnut ,st4 ,bridge1 and from ,smith's ,island1 in which the distance from the border in one case is1 as stated above1 quite different from that in the other4 ,in specimens from ,morris ,cove1 ,conn41 the locality referred to by ,rattray1 variations occur4 ,blue clay4 ,pl4 #f1 ,fig4 #a4 ,in the figure the subulate hyaline spaces at the border are1 in some instances1 wider than usual4 ,,actinocyclus ,,moniliformis ,,ralfs ,surface flat1 from centre to about five-sixths of the radius4 ,central space rounded1 with one or more granules4 ,markings1 #h in #aj 1 round1 in radial rows1 fasciculate1 the oblique transverse rows irregular1 very slightly decreasing until near the edge of the flattened zone1 and then suddenly decreasing and appearing as decussating lines oblique to the border4 ,apiculi distinct1 interfasciculate within the border4 ,nodule quite evident1 surrounded by a rather wide irregular hyaline space on the margin of the flattened zone in the middle of the fasciculus4 ,border wide1 with stri about #bj in #aj 4 ,blue clay4 ,port ,penn4 ,not common4 ,pl4 #f1 ,fig4 #b4 ,equivalent to ,actinocyclus ehrenbergii1 ,h4 ,l4 ,s4 ,type ,slide #aj4 ,in a valve from ,port ,penn1 ,delaware ,bay1 two nodules occur nearly opposite each other4 ,,actinocyclus ,,ellipticus ,,var4 ,,delawarensis ,n4 ,,var4 ,valve rhombic-elliptical4 ,markings somewhat angular1 #f in #aj at the centre where they are sub-concentric1 thence decreasing in lines radiating more or less toward the border1 where they suddenly become punctiform1 stri about #bj in #aj 4 ,border equal to one-fifth the radius4 ,a nodule is found on the inner side of the border4 ,apiculi apparently absent4 ,the markings are larger than in the ,richmond forms which are associated by ,rattray with ,actinocyclus ellipticus ,grun4 ,the form corresponds closely to ,witt's ,cestodiscus ovalis var48 7,witt1 ,polierschief4 von ,archangelsk-,kurojedowo1 ,pl4 #h1 ,fig4 #b71 except as to the border4 ,it does not answer to ,van ,heurck's figure or any other4 ,blue clay4 ,very rare4 ,pl4 #c1 ,fig4 #f4 #bh;,,eupodiscus ,,ehr4 7#ahdd7 7eu1 well1 pous1 a foot1 and discus7 ,valve circular1 #de-aag in diam4 7,de ,toni74 ,central space absent1 surface plane with angular cells4 ,at the border short1 circular processes or ocelli4 ,,eupodiscus ,,radiatus ,,bail4 ,valve with radiating hexagonal cells1 sometimes slightly curved toward the large ocelli inserted near the border which are hyaline at the centre4 ,border wide1 coarsely striate4 ,the number of ocelli heretofore recorded is four4 ,specimens with five processes are found in the artesian well at ,st4 ,augustine1 ,fla41 and in material at ,twelfth and ,brandywine ,sts4 ,mr4 ,hugo ,bilgram has discovered valves with three and six ocelli4 ,not common in the blue clay1 but abundant along the southern coast of the ,atlantic states and the ,gulf of ,mexico4 ,not ,eupodiscus radiatus ,wm4 ,sm1 which is ,biddulphia smithii 7,ralfs7 ,v4 ,h4 ,pl4 #e1 ,fig4 #c4 ,,auliscus ,,ehr4 7#ahdc7 7aulax1 a furrow1 referring to the grooves in certain species1 according to ,de ,toni1 but preferably from auliscos1 a small reed1 referring to the processes87 ,frustule cylindrical2 zone with longitudinal rows of fine puncta4 ,valve circular or elliptical1 plane except near the processes2 central area hyaline1 usually circular4 ,markings of two kinds1 granules radiating or scattered and radiating1 costate lines1 prominent or indistinct4 ,processes1 two or three1 large1 short1 cylindrical1 with hyaline surface1 near the ends of the major axis in a line oblique to it4 ,auliscus is divided by ,rattray into fourteen sections1 defined chiefly by the character and arrangement of the markings4 ,about eighty species are described1 but as many of the forms are fossil1 occuring in the ,miocene of ,california1 ,oamaru and elsewhere1 and as so few species are found in this locality1 ,i shall refer but briefly to this division4 ,striolati4--,no transverse median areas1 stri inconspicuous punctatus ,lineolati4--,markings distinct1 pruinose1 interrupted pruinosus ,costati4--,transverse median areas usually distinct1 sculptus markings continuous1 costate clatus ,,auliscus ,,punctatus ,,bail4 ,valve broadly elliptical1 or suborbicular1 covered with delicate interrupted stri radiating in sinuous lines to the circumference1 more evident on the transverse median area2 puncta #c in #aj 1 grouped into a rounded area on each side of the median line1 elsewhere scattered4 ,central space rounded1 processes two1 large1 suborbicular4 ,port ,penn1 ,delaware ,river4 ,rare4 ,pl4 #e1 ,fig4 #f4 ,,auliscus ,,pruinosus ,,bail4 ,valve elliptical1 with distinct1 interrupted1 pruinose1 irregular markings diverging in curved lines toward the circumference in the median part and converging toward the processes1 interspersed with numerous darker markings having the appearance of apiculi4 ,central space nearly circular1 sometimes with several granules4 ,processes large near the ends of the major axis and not oblique to it1 or scarcely so1 the edges with a crenulate border4 ,blue clay4 ,rather rare4 ,pl4 #e1 ,fig4 #h4 #bi;,,auliscus ,,sculptus 7,,wm4 ,,sm47 ,,ralfs ,valve elliptical or subcircular1 median areas distinct1 rounded1 circumscribed by coarse distant cost radiating near the border where they are more evident1 and converging toward the processes4 ,central space rounded1 sometimes indefinite4 ,processes1 two1 circular4 ,typical specimens show wide1 coarse1 distant cost1 but1 in some cases1 the median areas are indistinctly outlined4 ,blue clay4 ,pl4 #e1 ,fig4 #e4 ,,auliscus ,c,,latus ,,bail4 ,valve elliptical or subcircular1 with radiating cost1 more evident around the median areas and at the border1 converging toward the processes1 with intermediate punctate radiating lines4 ,central space rounded or irregular4 ,processes circular4 ,a4 sculptus has coarser cost and the interspaces are hyaline1 or apparently so1 while in ,a4 clatus the punctate stri between the cost are more evident4 ,blue clay4 ,not uncommon4 ,pl4 #e1 ,fig4 #d4 ,fig4 #g is a small1 indefinite form intermediate between ,a4 sculptus and ,a4 clatus4 ,the numerous variations in this genus make it difficult to satisfactorily differentiate the species4 ,the size of the four above described varies from #dj to #aej 4 ,,pseudauliscus ,a4 ,s4 7#ahge7 ,,and ,,leuduger-,,fortmorel 7#ahgi7 ,valve circular or subcircular1 nearly flat or depressed at the centre4 ,central space not evident4 ,processes circular1 with narrow border1 near the circumference4 ,border narrow1 striated4 ,markings granular1 radiating1 sometimes interspersed with stri and apiculi4 ,differs from ,auliscus chiefly in the absence of a central space and cost4 ,,pseudauliscus ,,radiatus 7,,bail47 ,,rattr4 ,valve circular1 or nearly so1 flat4 ,central area with scattered granules radiating and increasing in size outward in diverging rows toward the border which is coarsely striated4 ,processes1 two1 circular4 ,two small apiculi are inserted at about one-fifth the radius from the border near the ends of the minor axis4 ,blue clay4 ,rare4 ,pl4 #e1 ,fig4 #i4 ,the apiculi are not always figured4 ,they appear in a number of specimens from the ,miocene of ,maryland1 ,atlantic ,city1 ,harvey ,cedars and ,newbern4 ,,pseudauliscus ,,spinosus 7,,christian7 ,,rattr4 ,valve subcircular or slightly quadrangular1 depressed at the centre and rising to an elevated zone near the border1 the two zones separated by a distinct line4 ,the inner zone indistinctly reticulate with fine puncta radiating from the centre and apiculi at intervals4 ,the outer zone with smaller apiculi surrounding the inner zone and with intermingled rows of fine puncta and interrupted diverging stri4 ,near each end of the minor axis is a rather long1 robust spine inserted at one-fourth the radius from the border which is narrow and striated4 ,processes circular1 close to the circumference4 ,auliscus spinosus ,christian4 ,blue clay4 ,rare4 ,pl4 #e1 ,fig4 #aj4 ,the genus is named by ,schmidt1 described by ,leuduger-,fortmorel and emendated by ,rattray4 #cj;,,biddulphioide ,,biddulphie 7a7 ,triceratiin4--,frustule cylindrical or prismatic1 with three or more sides4 7b7 ,biddulphiin4--,frustule cylindroid2 valve with ends elevated into round processes or long horns4 7c7 ,anaule4--,valve elliptical1 lunate or triangular1 with internal septa4 7d7 ,euodie4--,frustule cuneate in zone view2 valve lunate4 7a7 ,,triceratiin 7#a7 ,ditylum4--,frustule imperfectly siliceous4 ,zone with numerous divisions4 ,valve with central spine4 7#b7 ,trinacria4--,processes with sharp spines4 ,,ditylum ,,bail4 7#ahfa7 7dis1 two1 and tyle1 a swelling1 referring to the outline of the frustule7 ,frustule quadrangular1 convex at the ends4 ,valve triangular1 with undulating sides1 the angles ending in a sharp point surmounted by a bristle4 ,surface of valve convex at centre from which projects a long stout spine4 ,,ditylum ,,intricatum 7,,west7 ,,grun4 ,valve with the angles separated from the central part by lines imitating septa4 ,surface with radiating lines of fine puncta4 ,blue clay4 ,rare4 ,pl4 #f1 ,fig4 #d4 ,detached valves only have been found in the blue clay4 ,the form is regarded as but slightly siliceous and1 therefore1 the zone or girdle not being found in the fossil deposits1 ,i am unable to illustrate it from material in the vicinity4 ,on ,plate #ch1 ,figs4 #f and #g1 ,i have sketched the zone and valve views of specimens found recently at ,vera ,cruz and labelled by ,h4 ,l4 ,smith ,triceratum intricatum ,west4 ,i can find no difference between the recent and fossil forms of the valves4 ,the zone is covered with fine puncta in quincunx1 not visible under ordinary illumination4 ,the form as figured in ,plate #f corresponds to the figure of ,lithodesmium undulatum ,ehr4 in ,van ,heurck1 and ,west1 in describing the ,triceratium undulatum ,wm4 ,sm4 7figured as ,t4 striolatum71 thought that his ,t4 intricatum was distinct from ,ehrenberg's form on the ground that the latter came from the ,bermuda 7,nottingham7 earth and must be strongly siliceous4 ,lithodesmium is characterized by the envelopment of the frustules by a cellular membrane which does not appear1 evidently1 in ,ditylum4 ,d4 brightwellii is distinguished by its crown of spines on the margin2 otherwise it closely resembles ,d4 intricatum4 ,,trinacria ,,heib4 7#ahfc7 7treis1 three1 and acra1 a point7 ,valve triangular1 angles elevated into spines4 ,cells at the margin large4 ,,trinacria ,,pileolus 7,,ehr47 ,,grun4 ,valve with concave sides4 ,surface concave with unequal punctiform and scattered markings with central dots4 ,cells at the margin large1 rounded4 ,at the angles1 which vary in elevation1 a few puncta are seen4 ,triceratium pileolus ,ehr4 ,blue clay4 ,rare4 ,pl4 #f1 ,fig4 #i4 #ca7;b7 ,,biddulphiin ,,biddulphia ,,gray 7#ahca7 em4 ,,van ,,heurck 7#ahhe7 7a genus1 constituted from ,conferva biddulphiana of the ,english ,botany1 named after a ,miss ,biddulph7 ,frustule prismatic or subcylindrical1 concatenate1 filamentous1 or in zig-zag1 or1 as usually found1 free4 ,zone well developed4 ,valve triangular1 polygonal1 elliptic or subcircular1 convex1 more or less elevated at the angles into processes or horns4 ,markings cellular or punctate4 ,chromatophores1 small plates of various forms4 ,,key ,,to ,,the ,,species ,valves costate biddulphiana ,valves not costate3 ,markings cellular1 angles elevated into horns favus angles not elevated antediluviana ,markings punctate1 angles with subconical processes and long spines granulata spines short rhombus spines minute smithii processes truncate1 valve elliptical turgida valve orbicular lvis processes absent1 valve divided by irregular lines alternans not so divided reticulum ,,biddulphia ,,biddulphiana 7,,smith7 ,frustule quadrangular with convex ends and rounded angles4 ,valve elliptical with undulated sides1 divided by septa into three or more sections4 ,processes large1 rounded1 globular or subconical4 ,zone varying in width4 ,surface with rounded reticulations in longitudinal and transverse rows1 except at the centre where they are concentric and smaller4 ,conferva biddulphiana ,smith 7,english ,botany1 #ahjg1 ,pl4 #agfb1 upper figures74 ,diatoma biddulphianum ,ag4 ,biddulphia pulchella ,gray4 ,blue clay4 ,hoboken ,tunnel4 ,along the coast4 ,pl4 #g1 ,figs4 #a1 #b1 #c1 and #d4 ,quite variable in size and number of septate divisions4 ,fig4 #c is an unusual form with narrow zone1 having but one row of large reticulations1 evidently a young frustule4 ,,biddulphia ,,favus 7,,ehr47 ,v4 ,h4 ,frustule quadrangular1 elevated at the angles into subconical processes oblique to the longitudinal axis4 ,valve triangular or quadrangular1 plane1 of two layers1 the outer layer composed of large hexagonal cells in rows parallel to the sides1 the inner of small puncta radiating from the centre4 ,zone punctate in quincunx1 never found open4 ,triceratium favus ,ehr4 ,blue clay4 ,common along the coast4 ,the quadrangular form occurs only southward4 ,pl4 #f1 ,fig4 #f4 ,at a a cell showing the lower punctate layer4 ,pl4 #dj1 ,fig4 #af1 a transverse section of a portion of the valve showing the cellular structure and the punctated lower stratum4 #cb;,,biddulphia ,,antediluviana 7,,ehr47 ,v4 ,h4 ,frustules quadrangular1 sometimes united in zig-zag chains4 ,valve quadrangular with more or less concave sides1 sometimes cruciform4 ,surface with angular cells arranged in concentric and radiating lines increasing toward the circumference4 ,at each angle is a large1 rounded process1 which1 as well as the secondary layer1 scarcely visible1 is finely punctate4 ,amphitetras antediluviana ,ehr4 ,amphitetras tessellata ,shad4 ,blue clay4 ,rare4 ,pl4 #f1 ,fig4 #c4 ,a cruciform variety occurs at ,pensauken1 ,n4 ,j41 artesian well 7,coll4 ,f4 ,j4 ,keeley74 ,,biddulphia ,,granulata ,,roper ,valve elliptical-lanceolate1 convex1 with diagonal rows of puncta #ab in #aj and sometimes with small scattered spurs4 ,processes inflated at the base1 obtuse at the ends1 which are curved outward toward alternate sides4 ,near each process and on opposite sides of the longitudinal axis is placed a stout spine bent or curved inward near the middle4 ,connective zone with diagonal rows of puncta smaller than those on the valve4 ,pavonia1 ,n4 ,j41 artesian well4 ,fossil in the ,pleistocene4 ,along the coast4 ,not common4 ,pl4 #g1 ,fig4 #f4 ,,biddulphia ,,rhombus 7,,ehr47 ,,wm4 ,,sm4 ,valve rhomboidal1 sometimes triangular1 with subconical processes4 ,surface convex with hexagonal reticulations1 #g-i in #aj 1 irregular at the centre and radiating to the circumference4 ,minute spurs are scattered over the surface1 and on each side are usually two or three short spines4 ,common along the coast and fossil in the ,miocene and later deposits4 ,pl4 #g1 ,fig4 #e 7somewhat inclined1 as usually seen74 ,,biddulphia ,,smithii 7,,ralfs7 ,v4 ,h4 ,valve orbicular1 convex1 with reticulations #e in #aj radiating from the centre and decreasing toward the margin and processes which are truncate4 ,a short spine is found on each side half way between the processes4 ,zone narrow with fine puncta #ab in #aj in longitudinal rows4 ,cerataulus smithii ,ralfs4 ,eupodiscus radiatus ,wm4 ,sm4 ,blue clay4 ,along the coast southward4 ,pl4 #g1 ,fig4 #h4 ,,biddulphia ,,turgida 7,,ehr47 ,,wm4 ,,sm4 ,valve elliptical or orbicular1 surface convex4 ,processes very large1 cylindrical1 placed obliquely and inclined by the torsion of the frustule4 ,between the processes are two stout spines1 one on each side1 frequently forked at the ends4 ,puncta fine1 irregular at the centre and radiating toward the circumference4 ,cerataulus turgidus ,ehr4 ,blue clay4 ,along the coast4 ,quite variable in size4 ,pl4 #g1 ,fig4 #g4 #cc;,,biddulphia ,l,,vis ,,ehr4 ,valve suborbicular or triangular1 with short1 truncate processes4 ,surface with fine puncta about #ac in #aj radiating in straight or curved lines toward the circumference and with fine spurs at intervals4 ,nearer one process than the other1 and about half way between centre and circumference1 are two small spines1 one on each side4 ,quite variable in size4 ,blue clay4 ,common along the coast4 ,pl4 #g1 ,fig4 #i4 ,fig4 #aj 7magnification about #bfj diameters only7 illustrates sporangial frustules discovered by ,mr4 ,t4 ,chalkley ,palmer at ,reedy ,island1 ,delaware ,river4 ,in frustules having a cylindrical form1 the endochrome lines the cell-walls in the form of granules which become congregated toward the centre in the sporangia4 ,,biddulphia ,,alternans 7,,bail47 ,v4 ,h4 ,valve triangular or1 rarely1 quadrangular1 with sides straight or slightly concave1 usually unequal4 ,angles obtuse1 separated from the centre by costate lines4 ,surface with puncta of irregular shape1 large at the centre1 with smaller puncta interspersed4 ,in many valves several lines appearing like cost extend inward from the border in various directions4 ,angles with small puncta in transverse and longitudinal rows4 ,triceratium alternans ,bail4 ,blue clay4 ,along the coast4 ,pl4 #f1 ,fig4 #g and probably ,fig4 #h4 ,,biddulphia ,,reticulum 7,,ehr47 ,frustule quadrangular4 ,valve triangular with straight or concave sides and rounded angles4 ,surface convex at the centre and angles4 ,markings of unequal size1 mostly larger at the centre1 scattered2 at the angles1 small puncta in longitudinal rows4 ,triceratium sculptum ,shad4 ,triceratium punctatum ,br4 ,triceratium obtusum ,br4 ,for explanation of the synonymy see ,biddulphoid ,forms of ,n4 ,a4 ,diat41 ,proc4 ,acad4 ,nat4 ,sci41 #aijj1 p4 #gbd4 ,blue clay4 ,along the coast4 ,pl4 #f1 ,fig4 #e4 7c7 ,,anaule ,,eunotogramma ,,weisse 7#ahed7 7eu1 well1 noton1 a back1 and gramma7 ,frustule quadrangular4 ,valve elliptical or lunate divided by septa which constrict the margin4 ,surface flat with punctate markings4 ,,eunotogramma ,l,,ve ,,grun4 ,valve lunate with obtuse ends4 ,septa1 from four to eleven or more4 ,surface with puncta in transverse and longitudinal rows1 sometimes indistinct and scattered4 ,shark ,river4 ,rare4 ,more common southward4 ,fossil at ,buckshutem1 ,n4 ,j4 ,pl4 #g1 ,fig4 #aa1 and ,pl4 #aj1 ,fig4 #ae4 ,i am unable to distinguish between ,e4 lve and ,e4 debile1 as intermediate forms occur4 #cd,,terpsino ,,ehr4 7terpsinoos1 gladdening87 ,frustules quadrangular1 adnate in filaments1 usually free4 ,valve elliptical or triangular1 with undulating sides divided by septa into three or more sections4 ,,terpsino ,,americana 7,,bail47 ,,ralfs ,valve lobed at each end or angle4 ,central space rounded1 hyaline4 ,surface with fine puncta in radiating lines4 ,blue clay4 ,not common4 ,pl4 #f1 ,fig4 #aj4 ,,terpsino ,,nov-,c,,sare ,,boyer ,valve triangular1 with concave sides and broad angles equally three-lobed1 separated from the central part by septa4 ,central space small or absent4 ,puncta delicate1 radiating or scattered4 ,l4 of side #fb 4 ,pleistocene clay at ,buckshutem1 ,n4 ,j4 ,fossil at ,wildwood1 ,n4 ,j4 ,t4 americana1 forma trigona ,pant48 7,le ,diatomiste1 ,vol4 #b1 p4 #bjg47 ,pl4 #f1 ,fig4 #aa4 7d7 ,,euodie ,,euodia ,,bail4 7#ahfj7 7derivation uncertain2 apparently from euodia1 fragrant1 probably a euphemism7 ,frustule in zone view cuneate4 ,valve semi-lunate1 coscinodiscoid4 ,,euodia ,,gibba ,,bail4 ,valve with rounded markings1 larger and scattered at the centre1 radiating at the circumference and in indefinite straight rows at the semi-radius4 ,delaware ,bay 7,mann74 ,pl4 #e1 ,fig4 #a4 ,i have not seen this in the ,philadelphia material4 ,the figure is drawn from a specimen from the ,gulf ,stream1 ,s4 ,atlantic4 #ce,,pennat ,valve zygomorphous4 ,structure pinnate1 not concentric4 ,valve divided either by a true raphe or cleft or by a linear space or line imitating a raphe4 ,divided into three ,groups3 #a4 ,fragilarioide4--,valves without a raphe2 usually with a pseudoraphe or median line4 #b4 ,naviculoide4--,either one or both valves with a true raphe4 #c4 ,surirelloide4--,valves in which the raphe is concealed near the margin on one or both sides of each valve in a more or less elevated keel or wing4 ,,fragilarioide 7a7 ,tabellarie4--,valve symmetrical with respect to both the longitudinal and transverse axes2 septate1 not cuneate4 7b7 ,meridione4--,valve symmetrical with respect to the longitudinal axis1 asymmetrical to the transverse axis1 cuneate1 finely striated4 7c7 ,fragilarie4--,valve of varied shape1 not cuneate2 costate or with transverse rows of puncta4 7a7 ,,tabellarie ,frustule in zone view rectangular1 in valve view linear or linear-elliptical1 sometimes constricted in the middle1 symmetrical to both axes1 not cuneate2 with two or more septa or annuli4 ,chromatophores numerous1 granular4 ,rhabdonema4--,frustules with numerous septate partitions having one or several foramina4 ,transverse cost or rows of coarse puncta4 ,tabellaria4--,frustules with two to six nearly straight septa4 ,transverse stri subtly punctate4 ,grammatophora4--,frustules with two sinuate perforate curved septa4 ,transverse stri subtly punctate4 ,striatella4--,frustules with alternate partitions1 septate or partly so4 ,attheya4--,frustules not septate but with numerous annuli4 ,,rhabdonema ,,kuetz4 7#ahdd7 7rhabdos1 a rod1 and nema1 a thread7 ,frustules quadrangular1 concatenate1 composed of numerous septate partitions with transverse cost or rows of puncta4 ,valves elliptical1 with a pseudoraphe and transverse apparent cost and punctate lines2 the partitions with one or several foramina4 ,chromatophores in rosettes of various kinds 7,karsten72 usually parallel to the septa4 ,,rhabdonema ,,arcuatum 7,,lyng47 ,,kuetz4 ,valve hyaline at the ends1 with transverse rows of puncta producing the appearance of cost between the rows2 pseudoraphe distinct2 foramen single4 ,diatoma arcuatum ,lyngbye4 ,common along the coast4 ,pl4 #h1 ,figs4 #a1 #b1 and #c2 ,pl4 #dj1 ,fig4 #aj4 #cf;,according to ,t4 ,h4 ,buffham 7,jour4 ,quek4 ,m4 ,c41 ,series #b1 ,vol4 #b1 p4 #aca71 the frustules are of two kinds1 those in which the length and breadth are the same and those which are much lengthened1 with a wide hyaline girdle frequently in the middle4 ,at the time of fructification the smaller frustules are attached to a larger one which produces a sporangium at the end of the girdle from which the other end of the frustule has disappeared1 or1 if the two halves of the frustule remain1 two sporangia are formed4 ,,rhabdonema ,,minutum ,,kuetz4 ,frustules small2 valve not smooth at the ends1 elliptical or lanceolate-elliptical1 with transverse rows of puncta2 pseudoraphe distinct4 ,foramen single1 alternating above and below in adjoining partitions4 ,common in the blue clay and along the coast4 ,pl4 #h1 ,fig4 #g and ,pl4 #ch1 ,fig4 #aa4 ,,rhabdonema ,,adriaticum ,,kuetz4 ,valve linear-lanceolate1 with smooth angles2 rows of puncta transverse1 the intervals appearing as cost1 as in arcuatum4 ,foramina1 three4 ,blue clay in the ,pensauken and ,pavonia deposits and along the coast4 ,pl4 #h1 ,figs4 #d1 #e and #f4 ,,tabellaria ,,ehr4 7#ahci7 7tabella1 a tablet7 ,frustules quadrangular1 adnate in filaments1 frequently found in zig-zag chains1 united by a gelatinous isthmus1 at length separating4 ,valve linear1 inflated in the middle and at the ends2 stri transverse4 ,chromatophores numerous1 small1 along the zones4 ,,tabellaria ,,fenestrata 7,,lyng47 ,,kuetz4 ,valve elongated2 pseudoraphe narrow2 transverse stri faint4 ,in the zone view a straight septum is shown at each end of a valve4 ,common1 especially in the cedar swamps and ponds of the ,pine ,barren region1 ,n4 ,j4 ,pl4 #h1 ,figs4 #aa and #ab4 ,,tabellaria ,,flocculosa 7,,roth7 ,,kuetz4 ,valve linear1 with median inflation larger than the terminal2 pseudoraphe rather broad in the middle2 transverse stri subtly punctate4 ,in zone view the frustules are quadrangular1 or nearly so1 with about six sometimes curved septa at one end alternating with those on the other end4 ,conferva flocculosa ,roth4 ,common especially in the ,pine ,barrens of ,new ,jersey4 ,pl4 #h1 ,figs4 #h1 #i and #aj4 ,,grammatophora ,,ehr4 7#ahdj7 7from gramma1 a letter1 and phoreo1 ,i bear7 ,frustules quadrangular1 adnate1 in zig-zag1 united by an isthmus1 or1 usually1 found free2 divided by two sinuate and perforate curved septa4 ,valve linear or oblong1 sometimes with sinuate sides1 and with a pseudoraphe and transverse punctate lines4 ,chromatophores granular4 #cg;,,grammatophora ,,marina 7,,lyng47 ,,kuetz4 ,valve linear-elliptical1 with smooth apices4 ,septum with a wide undulation near its origin1 thence straight and incrassate at the end4 ,stri in quincunx1 #ah-ba in #aj 4 ,diatoma marinum ,lyngbye4 ,blue clay4 ,along the coast4 ,pl4 #h1 ,figs4 #ag and #ah4 ,,grammatophora ,,marina ,,var4 ,,subtilissima 7,,bail47 ,v4 ,h4 ,valve linear1 slightly constricted near the smooth apices4 ,septum undulated near its origin and then straight1 incrassate at the end4 ,puncta in quincunx very subtle1 #cd-cf in #aj 4 ,grammatophora subtilissima ,bail4 ,grammatophora oceanica var4 subtilissima 7,bail47 ,v4 ,h41 according to ,de ,toni4 ,g4 marina and ,g4 oceanica are united by some authors2 the latter has more subtle stri4 ,along the coast4 ,pl4 #h1 ,figs4 #ac and #ad4 ,,grammatophora ,,serpentina ,,ralfs ,valve linear-elliptical1 long1 measuring to #aej 7,de ,toni72 smooth at the apices4 ,septum with numerous undulations and hooked at the apex4 ,puncta in quincunx1 #ag in #aj 4 ,along the coast4 ,pl4 #h1 ,fig4 #ba4 ,,grammatophora ,,angulosa ,,var4 ,,hamulifera 7,,kuetz47 ,,grun4 ,frustule nearly quadrate2 valve with rounded but not smooth apices4 ,septum bent into a sharp angle near its origin and ending in a broad hook4 ,puncta in transverse rows1 #ad in #aj 4 ,along the coast4 ,pl4 #h1 ,figs4 #ae and #af4 ,,grammatophora ,,islandica ,,ehr4 ,frustule oblong2 valve elliptical-lanceolate4 ,septum robust with several undulations and hooked at the end4 ,pseudoraphe distinct2 transverse rows of puncta1 #aj in #aj 4 ,reported by ,kuetzing in the ,atlantic ,ocean and by ,kain at ,belmar1 ,n4 ,j4 ,i have not found it on our coast and ,i believe1 in some cases1 it has been confused with ,g4 angulosa var4 hamulifera4 ,the figure is drawn from an ,iceland form in ,h4 ,l4 ,smith ,t4 ,s41 #ahf4 ,pl4 #h1 ,figs4 #ai and #bj4 ,,striatella ,,ag4 7#ahcb7 7dim4 of stria1 referring to the lines on the frustule7 ,frustules tabulate1 adnate in short1 stipitate filaments1 scarcely siliceous1 divided into partitions1 septate or partly so at alternate ends4 #ch,,striatella ,,unipunctata 7,,lyng47 ,,ag4 ,frustules with numerous bent septa extending the entire length4 ,valve lanceolate1 somewhat unsymmetrical1 subtly punctate1 with pseudoraphe quite distinct4 ,the specific name is derived from the appearance of the endochrome which in the living specimen is invariably collected in a central mass with slender threads radiating in all directions toward the cell-wall 7,wm4 ,sm474 ,pyrenoids cuneate1 in the centre of the endochrome1 numerous4 ,long ,island ,sound and along the coast4 ,pl4 #h1 ,figs4 #bb and #bc4 ,,striatella ,,interrupta 7,,ehr47 ,,heib4 ,frustules quadrangular1 with robust alternate septa extending to the middle4 ,puncta in quincunx1 #bb in #aj 4 ,tessella interrupta ,ehr4 ,very rare along the coast4 ,pl4 #h1 ,fig4 #bd4 7,from a form found at ,stonington1 ,conn47 ,,attheya ,,west 7#ahfj7 7named after ,thomas ,atthey7 ,frustules quadrangular1 tabulate1 with numerous annuli4 ,valve elliptical-lanceolate1 with a pseudoraphe and a central punctum4 ,extending from each end is a strong spine half as long as the valve4 ,,attheya ,,decora ,,west ,the only species4 ,diagnosis of the genus4 ,the valves are imperfectly siliceous1 scarcely visible in balsam4 ,very local4 ,abundant at ,shark ,river1 ,n4 ,j4 ,pl4 #h1 ,fig4 #be4 7b7 ,,meridione ,valve symmetrical in zone and valve view along the sagittal line1 but asymmetrical to the transverse axis1 cuneate4 ,in zone view sometimes with wedge-shaped septa4 ,valve finely striated1 without central and usually without terminal nodules2 a pseudoraphe present4 ,licmophora4--,frustules cuneate in stipitate fan-shaped fascicles4 ,meridion4--,frustules cuneate in spiral fascicles4 ,,licmophora ,,ag4 7#ahbg7 7licmos1 a fan1 and phoreo1 ,i bear7 ,frustules wedge-shaped1 joined together into fan-shaped1 stipitate fascicles4 ,valve cuneate1 rounded at both ends1 septate4 ,chromatophores granular1 round or oval in our species4 #ci;,,analysis ,,of ,,species 7,in accordance1 so far as it relates to our species1 with the classification of ,c4 ,mereschkowsky1 ,diagnoses of ,new ,licmophor1 ,nuova ,notarisia1 #aija47 ,placat--valve narrow1 stri very fine1 septa superficial flabellata ,dubi--valve bacilliform1 septa shallow1 frustule with thick walls ovulum ,paradox--valve with lower end produced1 stri fine1 paradoxa pseudoraphe distinct1 septa deep gracilis tincta baileyi 8 ,lyngbye--valve narrow1 attenuated at both ends1 distinct1 septa deep lyngbyei ,peristriat--valve broad1 pseudoraphe wide1 stri robust ehrenbergii ,,licmophora ,,flabellata 7,,carm47 ,,ag4 ,frustule elongate1 narrow2 valve narrow1 lanceolate-cuneate1 enlarged at the base2 stri very fine1 #cj in #aj 4 ,echinella flabellata ,carm4 ,licmophora splendida ,wm4 ,sm4 ,common along the coast4 ,pl4 #i1 ,figs4 #a and #b4 ,,licmophora ,,ovulum ,,mer4 ,valve ovate1 attenuated to the rounded inferior apex2 pseudoraphe indistinct1 stri fine1 #bd in #aj 4 ,zone view broad1 cuneate1 angles rounded1 inferior apex broad2 frustule robust1 septa superficial1 straight4 7,mereschkowsky1 in part47 ,atlantic ,city4 ,common4 ,pl4 #i1 ,figs4 #h and #i4 ,,licmophora ,,paradoxa 7,,lyng47 ,,ag4 ,frustule broad1 with rounded angles2 septa curved2 valve ovate1 inferior apex produced4 ,pseudoraphe distinct2 stri varying from #be below to #cj above in #aj 4 ,echinella paradoxa ,lyng4 ,rhipidophora paradoxa ,kuetz4 ,along the coast4 ,pl4 #i1 ,figs4 #f and #g4 ,,licmophora ,,gracilis 7,,ehr47 ,,grun4 ,frustule cuneate1 narrow1 with sinuate margin2 valve clavate1 linear at the base2 stri1 #bj to #bb in #aj 4 ,new ,rochelle4 ,along the coast4 ,pl4 #i1 ,fig4 #aa4 ,,licmophora ,,gracilis ,,var4 ,,elongata 7,,kuetz47 ,,de ,,toni ,as in the type1 but more graceful and with deeper septa4 ,rhipidophora elongata ,kuetz4 ,along the coast4 ,not common4 ,pl4 #i1 ,figs4 #ab and #ac4 #dj,,licmophora ,,tincta 7,,ag47 ,,grun4 ,frustules cuneate1 narrow1 usually found in twos4 ,valve clavate1 hyaline1 rather broad at the base2 septa moderately deep2 pseudoraphe indistinct2 stri1 #bg at the base1 #cj in the middle and #cc at the apex in #aj 4 ,gomphonema tinctum ,ag4 ,along the coast4 ,abundant from about the middle of ,july to the middle of ,august4 ,pl4 #i1 ,figs4 #ad and #ae4 ,,licmophora ,,baileyi 7,,edw47 ,,grun4 ,frustule broadly cuneate or with convex margins1 rarely almost orbicular2 valve spatulate or ovate with slender1 produced base2 septa very deep2 pseudoraphe distinct2 stri #bj in #aj 4 ,podosphenia baileyi 7,edw47 ,lewis4 ,long ,island ,sound and upper coast of ,new ,jersey4 ,this form is placed in a doubtful position by ,mereschkowsky4 ,as it corresponds more closely to the ,paradox1 it is placed here provisionally4 ,the girdle face and apex of the valve are round1 the pseudoraphe is distinct and the septa deep1 but the stipe is short4 ,pl4 #i1 ,fig4 #aj and ,pl4 #ch1 ,figs4 #c and #d4 ,,licmophora ,,lyngbyei 7,,kuetz47 ,,grun4 ,frustule cuneate1 slightly rounded at the angles4 ,valve oblanceolate2 pseudoraphe distinct2 septa deep2 stri1 #ab in #aj below1 and #af in #aj above4 ,podosphenia lyngbyei ,kuetz4 ,along the coast4 ,pl4 #i1 ,figs4 #c and #d4 ,,licmophora ,,ehrenbergii 7,,kuetz47 ,,grun4 ,frustule cuneate1 broad4 ,valve obovate-lanceolate2 pseudoraphe wide2 stri coarse1 #h in #aj 1 moniliform4 ,podosphenia ehrenbergii ,kuetz4 ,along the coast4 ,pl4 #i1 ,fig4 #e4 ,,meridion ,,ag4 7#ahbd7 7merizo1 ,i divide7 ,frustules in zone view cuneate1 adnate in circular or spiral fasci1 at length becoming free4 ,valve symmetrical with respect to the longitudinal axis1 more or less cuneate2 cost and stri transverse4 ,chromatophores numerous1 small1 elongated1 in irregular rows on the zone 7,pfitzer74 ,,meridion ,,circulare 7,,grev47 ,,ag4 ,transverse cost coarse1 variable in number and distance apart1 sometimes interrupted or indistinct2 stri interstitial1 #af in #aj 4 ,in springs and small streams of pure water4 ,echinella circularis ,grev4 #da,meridion constrictum ,ralfs1 sometimes given as a variety of ,m4 circulare1 differs only in the constriction below the apex4 ,the two kinds of frustules are usually found growing together and as the variation is often extremely slight they are here included under the earlier name4 ,pl4 #aj1 ,figs4 #a1 #b and #c4 ,fig4 #a represents the constricted form which is the more common4 ,fig4 #c is a sporangial form4 ,the sporangial frustules vary in shape and size1 some being long and slender1 others clavate1 but they are all more or less tumid in the middle1 with cost more indefinite than in perfect valves4 ,all gradations occur1 one end becoming shorter until the valve has the shape of the variety known as constrictum4 ,it would seem1 therefore1 that the non-constricted form is a passage from the sporangial to the smaller or adult form1 or is of no specific importance4 ,all forms are found living together4 ,the adult frustules are the smaller ones2 it is from them that the sporangia are produced4 ,meridion intermedium ,h4 ,l4 ,smith 7,amer4 ,quart4 ,mic4 ,jour41 ,vol4 #a1 p4 #ab7 is characterized by less evident cost and is more delicate in general appearance4 ,some forms are capitate and others are not4 ,prof4 ,smith compares the ,m4 intermedium with ,peronia erinacea ,brb4 and ,arnott which he has named ,m4 erinaceum1 hitherto found only in ,europe1 and points out the relation of the two forms to ,licmophora4 ,an examination of the ,h4 ,l4 ,s4 type slides of the two diatoms proves that ,peronia has very delicate cost and a distinct pseudoraphe not noticeable in ,meridion4 ,on the slide of ,peronia are frustules exactly similar to certain of the sporangial variations of ,m4 circulare4 ,the fan-like arrangement of ,licmophora1 the marine form1 and the circular chains of ,meridion1 the fresh-water genus1 are similar4 ,both are stipitate at the beginning of their growth4 7c7 ,,fragilarie ,divided into three sections3 ,diatomin4--,valve circular1 elliptical to linear1 quadrate or cruciform1 with transverse cost2 without raphe1 a pseudoraphe sometimes wanting4 ,fragilariin4--,valve elongate1 with small central and terminal elevations1 without cost but with transverse punctate stri2 without genuine central nodule4 ,eunotiin4--,valve lunate2 a raphe sometimes partially formed with terminal nodules near the edges4 ,,diatomin ,diatoma4--,frustules in filaments4 ,valve linear or elliptical1 costate4 ,plagiogramma4--,frustules in fasci or free4 ,valve costate4 ,opephora4--,valve costate1 with an inner punctate stratum4 ,,diatoma ,,de ,,candolle 7#ahje7 em4 ,,heib4 7#ahfc7 7diatemno1 ,i cut in two7 ,frustules oblong or quadrate1 adnate in filaments1 attached by alternate angles and finally separating4 ,valve linear or elliptical1 with transverse cost and rows of puncta and a pseudoraphe4 ,chromatophores large granules without definite arrangement4 7,see ,pl4 #dj1 ,fig4 #aa47 #db;,,diatoma ,,vulgare ,,bory4 ,valve elliptical-lanceolate1 with apices sometimes rostrate or capitate2 pseudoraphe narrow2 cost1 #e in #aj 4 ,common everywhere in pure fresh water and extremely variable4 ,pl4 #aj1 ,figs4 #i and #aj4 ,var4 elongatum 7,ag47 var4 ehrenbergii 7,kuetz47--elliptical-lanceolate1 constricted near the apex4 ,var4 grande 7,wm4 ,sm47 ,grun4--linear1 elongated1 constricted near the apices4 ,pl4 #aj1 ,fig4 #d4 ,both of these varieties1 with numerous intermediate forms1 are abundant near ,newtown ,square4 ,varieties of ,grunow1 known as breve1 ovate-lanceolate2 productum1 ovate-lanceolate with produced apices2 capitulatum1 lanceolate with capitate extremities1 are mingled together in the same gathering4 ,,diatoma ,,anceps 7,,ehr47 ,,kirchn4 ,valve linear with rostrate apices2 cost robust2 stri delicate1 #bj in #aj 4 ,zone view quadrangular4 ,common in fresh water4 ,pl4 #aj1 ,figs4 #e and #f4 ,fig4 #aa1 ,pl4 #dj1 shows frustules containing the nuclei and chromatophores4 ,,diatoma ,,hiemale 7,,lyng47 ,,heib4 ,valve ovate-lanceolate to lanceolate2 apices obtuse1 not produced4 ,cost not numerous1 robust2 stri moniliform4 ,zone view quadrate1 the cost as septa deeply dividing the valve into convex elevations4 ,common in springs4 ,pl4 #aj1 ,figs4 #g and #h4 ,in all species of ,diatoma a punctum1 or pore1 is observed1 usually at alternate ends of the two valves1 by means of which a communication exists between adjoining frustules and causes them to adhere in zig-zag chains when partially separated4 ,,plagiogramma ,,grev4 7#ahei7 7plagios1 on the side1 and gramma1 a letter7 ,frustules quadrangular1 adnate in fasci1 or free4 ,valve linear1 elliptical1 or elliptical-lanceolate1 divided by two or more median and two terminal cost or with a central and two terminal hyaline spaces4 ,valve with two median and two terminal cost3 ,linear1 pseudoraphe distinct pygmum ,linear1 with stri at the ends wallichianum ,ovate-lanceolate obesum ,valve without cost but with central and terminal nodules3 pseudoraphe absent tessellatum #dc,,plagiogramma ,,pygm,,um ,,grev4 ,valve linear-elliptical2 pseudoraphe distinct2 rows of granules transverse1 usually six in each compartment1 moniliform1 three on each side4 ,blue clay4 ,not common4 ,pl4 #aj1 ,fig4 #ac4 ,,plagiogramma ,,wallichianum ,,grev4 ,valve linear1 rounded at the ends2 pseudoraphe absent2 transverse rows of granules1 six or seven in each compartment1 and two or three rows of smaller granules at each end4 ,blue clay4 ,not common4 ,pl4 #aj1 ,fig4 #ad4 ,,plagiogramma ,,obesum ,,grev4 ,valve rhombic-lanceolate1 the cost scarcely visible2 pseudoraphe rather wide2 rows of granules1 about seven in each compartment1 slightly radiating4 ,blue clay4 ,not common4 ,pl4 #aj1 ,fig4 #ab4 ,,plagiogramma ,,tessellatum ,,grev4 ,valve elliptical-lanceolate2 central space transversely elliptical to the major axis1 half the diameter of the valve2 terminal spaces more or less circular or ovate4 ,granular markings large1 quadrangular1 in transverse rows4 ,pseudoraphe not distinct4 ,as the central space does not reach the margin1 it is a question whether this form is a ,plagiogramma or a new genus4 ,blue clay4 ,rare4 ,pl4 #aj1 ,fig4 #aa4 ,,opephora ,,petit 7#ahhh7 7ope1 an opening1 and phoreo7 ,frustule rectangular4 ,valve cuneiform1 linear or elliptical-lanceolate1 with broad1 transverse stri and a well-defined pseudoraphe or median area4 ,the genus portant des stries en forme de boutonnires1 as ,petit remarks1 is quite near ,fragilaria1 under which the species here described were originally included4 7,see ,schmidt's ,atlas1 ,pl4 #bih1 where numerous forms of ,f4 pinnata are figured47 ,,opephora ,,schwartzii 7,,grun47 ,,petit ,valve obovate-lanceolate or nearly linear with rounded apices2 stri transverse1 broad1 #c or #d in #aj 2 median area lanceolate4 ,an inner stratum1 with puncta in transverse rows1 is apparent4 ,blue clay4 ,not uncommon4 ,variable in size4 ,pl4 #aj1 ,figs4 #af and #ai4 ,,opephora ,,pacifica 7,,grun47 ,,petit ,valve linear1 oblong1 with rounded apices4 ,median area linear1 narrow2 stri punctate4 ,blue clay4 ,pl4 #aj1 ,fig4 #ah4 ,petit 7,diat4 ,cap ,horn7 in his diagnosis states that the valves are cuneiform1 but they are not always so4 #dd,,opephora ,,pinnata ,,var4 ,,lanceolata ,n4 ,,var4 ,valve lanceolate2 cost slightly radiate1 punctate2 median area broad1 lanceolate4 ,differs from ,o4 pinnata in outline1 radiation of the cost and median area4 ,blue clay4 ,rare4 ,pl4 #aj1 ,fig4 #ag4 ,,fragilariin ,fragilaria4--,frustules in fasci4 ,valve with transverse stri4 ,pseudoraphe indistinct4 ,rhaphoneis4--,stri radiate2 pseudoraphe distinct4 ,dimerogramma4--,pseudoraphe broad4 ,trachysphenia4--,valve cuneiform4 ,synedra4--,valve elongate4 ,asterionella4--,frustules in star-shaped clusters4 ,,fragilaria 7,,lyng47 ,,rab4 7fragilis1 because of the fasci easily breaking up7 ,frustules rectangular1 adnate in fasci1 soon breaking up4 ,valve lanceolate1 oblong or elliptical in general outline1 with convex or sinuate margins2 without cost2 pseudoraphe narrow or indistinct2 stri transverse4 ,chromatophores vary according to species4 ,in some they consist of four bands on the valves2 in others they are granular 7,mereschkowsky74 ,brun divides the genus into two sections1 ,fragilaria proper and ,staurosira4 ,the former1 with an indistinct pseudoraphe1 includes the species virescens1 arctica1 undata and linearis1 while the latter1 with distinct pseudoraphe1 includes capucina1 harrisonii1 construens and parasitica4 ,,fragilaria ,,virescens ,,ralfs ,frustules in long fasci4 ,valve elliptical-lanceolate1 obtuse at the apices2 pseudoraphe indistinct2 stri1 #ag in #aj 1 punctate4 ,very common in springs and pure streams4 ,the fasci are often a foot or more in length4 ,pl4 #aj1 ,figs4 #bj and #ba4 ,,fragilaria ,,arctica ,,grun4 ,valve oblong or elliptical1 #aj in length2 stri subtle1 with coarse1 short stri at intervals on the margin and evident in zone view4 ,marine4 ,common at ,cape ,may1 ,n4 ,j4 ,pl4 #aj1 ,figs4 #bb and #bc4 ,,fragilaria ,,undata ,,wm4 ,,sm4 ,valve in general outline linear-elliptical1 with extremities produced2 stri subtle2 pseudoraphe distinct4 ,fresh water4 ,pl4 #aj1 ,figs4 #bd1 #be1 #bg1 #bh and #bi4 #de;,,fragilaria ,,linearis ,,cstr4 ,valve linear1 with rounded apices2 stri subtle2 pseudoraphe indistinct4 ,marine4 ,cape ,may4 ,pl4 #aj1 ,fig4 #cg4 ,fig4 #cf is an indeterminate form occasionally found in the blue clay4 ,,fragilaria ,,capucina ,,var4 ,,mesolepta ,,rab4 ,valve linear1 constricted at the hyaline middle2 apices slightly produced2 stri1 #ag in #aj 4 ,quite variable in size4 ,schuylkill ,river4 ,morrisville 7,keeley74 ,pl4 #aj1 ,fig4 #cd4 ,,fragilaria ,,harrisonii 7,,wm4 ,,sm47 ,,grun4 ,frustules rectangular1 solitary or in twos4 ,valve cruciform2 pseudoraphe narrow1 lanceolate2 stri robust1 radiating in the middle1 composed of confluent puncta1 larger at the circumference4 ,blue clay4 ,pl4 #aj1 ,fig4 #ca4 ,,fragilaria ,,construens 7,,ehr47 ,,grun4 ,valve in general outline lanceolate1 with produced apices2 pseudoraphe lanceolate1 distinct or broad2 stri subtle1 #ae in #aj 4 ,l4 of valve1 #aj-de 4 ,staurosira construens ,ehr4 ,odontidium tabellaria ,wm4 ,sm4 ,blue clay4 ,pl4 #aj1 ,fig4 #cj4 ,,fragilaria ,,parasitica 7,,wm4 ,,sm47 ,frustules solitary or in twos4 ,valve lanceolate1 sometimes constricted in the middle2 pseudoraphe wide1 lanceolate2 stri subtle4 ,parasitic on other diatoms4 ,odontidium parasiticum ,wm4 ,sm4 ,not common4 ,media 7,palmer74 ,in the constricted form it is known as ,f4 construens var4 binodis 7,ehr47 ,grun4 ,pl4 #aj1 ,fig4 #ce4 ,an examination of the synonymy of the species of ,fragilaria will convince the student of the difficulty of determining the correct name even in well-known forms4 ,if all of the species of ,fragilaria proper have granular chromatophores1 and all of ,staurosira are placcochromatic1 a satisfactory division can be made1 but so long as these facts are not known in all species1 and as authors have repeatedly confused the two divisions1 the nomenclature will be uncertain4 ,f4 harrisonii is probably in any case to be separated from the others4 ,de ,toni includes it under its original name of ,odontidium1 which genus he places near to ,diatoma4 ,the number of species in our locality is too limited to render further discussion of any value4 #df,,rhaphoneis ,,ehr4 7#ahdd7 7rhaphis1 a needle7 ,frustule in zone view linear4 ,valve lanceolate or elliptical-lanceolate2 pseudoraphe distinct2 stri radiating1 moniliform4 ,,rhaphoneis ,,amphiceros ,,ehr4 ,valve lanceolate1 broad1 with apices produced2 stri in curved lines1 moniliform1 the large granules in longitudinal lines4 ,blue clay4 ,pl4 #aj1 ,fig4 #ch4 ,,rhaphoneis ,,amphiceros ,,var4 ,,rhombica ,,grun4 ,valve as in type form but shorter1 with larger and more remote granules4 ,blue clay4 ,pl4 #aj1 ,figs4 #ci and #dj4 ,,rhaphoneis ,,belgica ,,var4 ,,intermedia ,,grun4 ,valve lanceolate1 rostrate2 granules in longitudinal and nearly transverse1 not radiating1 lines4 ,absecon1 ,n4 ,j4 ,pl4 #aj1 ,fig4 #da4 ,,dimerogramma ,,ralfs 7#ahfa7 7dis1 two1 meros1 a part1 gramma1 a letter7 ,frustules quadrangular1 inflated at the angles1 in fasci4 ,valve ovate or lanceolate2 stri moniliform1 transverse or slightly radiate2 median area or pseudoraphe broad1 lanceolate4 ,,dimerogramma ,,marinum 7,,greg47 ,,ralfs ,valve lanceolate or linear and inflated in the middle2 stri moniliform1 transverse or slightly radiate2 median area linear or lanceolate1 sometimes not reaching the smooth extremities2 stri1 #h in #aj 4 ,pl4 #ab1 ,figs4 #i and #aj4 ,fig4 #i differs in its lanceolate outline1 in having four puncta on each side in a row1 and in the stri which are radiate4 ,,dimerogramma ,,surirella 7,,ehr47 ,,grun4 ,valve elliptical-lanceolate1 with rounded apices2 stri moniliform1 radiate2 pseudoraphe narrow1 lanceolate4 ,blue clay4 ,pl4 #ab1 ,fig4 #aa4 #dg;,,dimerogramma ,,minus 7,,greg47 ,,ralfs ,valve rhombic-lanceolate2 stri punctate1 radiate2 pseudoraphe lanceolate2 apices smooth4 ,blue clay4 ,along the coast4 ,pl4 #ab1 ,figs4 #ab1 #ac1 #ad4 ,,trachysphenia ,,petit 7#ahgg7 7trachys1 rough1 and sphen1 a wedge7 ,frustules rectangular4 ,valve cuneiform with coarse puncta in transverse and longitudinal lines2 pseudoraphe narrow1 linear4 ,one species only4 ,,trachysphenia ,,australis ,,petit ,characters of the genus4 ,valve small2 puncta1 #f in #aj 4 ,allied to ,dimerogramma4 ,shark ,river1 ,n4 ,j4 ,rare4 ,pl4 #ab1 ,fig4 #ae4 ,,synedra ,,ehr4 7#ahcj7 7synedrion1 a sitting together7 ,frustules adnate in small stipitate clusters or free4 ,valve elongate1 linear or linear-lanceolate2 pseudoraphe distinct2 cost absent4 ,the genus ,synedra has few distinctive characters4 ,as ,brun remarks 7,diat4 des ,alpes et du ,jura1 p4 #abb71 the dilatation of the extremities and the pseudo-nodule are of little value in classification1 as the intermediate forms are so numerous4 ,fragilaria occurs in very long ribbons or fasci1 ,synedra in short fasci or radiating clusters4 ,fragilaria is seldom longer than three or four times the width1 while ,synedra is nearly always so4 ,the former has fine1 often subtle1 markings and narrow pseudoraphe1 while the latter has coarser punctate stri and a more distinct pseudoraphe4 ,chromatophores usually consist of two bands1 one on each of the valves4 ,karsten states that in the marine forms the chromatophores are oval or polygonal discs1 each of which usually encloses a pyrenoid4 ,,synedra ,,ulna 7,,nitzsch7 ,,ehr4 ,frustules solitary or in twos4 ,valve #aej-bej in length1 linear or linear-lanceolate1 with rostrate apices2 stri1 #i in #aj 4 ,common in rivers and streams4 ,pl4 #aa1 ,figs4 #d1 #g and #aa 7874 ,frequently interrupted in the middle4 ,the distinction made by ,wm4 ,smith as to the presence or absence of the central blank space is probably not necessary1 as both forms are found which are otherwise identical4 ,fig4 #e represents the formation of a sporangial frustule which differs from the usual form in its inflated ends prolonged into rostrate apices4 ,figs4 #a and #f are sporangial frustules4 #dh,,synedra ,,biceps 7,,kuetz47 ,,schmidt ,valve sublanceolate1 inflated at the ends1 apices rounded2 central space not always distinct2 pseudoraphe narrow2 stri radiate at the ends4 ,this is not ,kuetzing's species1 if the descriptions and figures are accepted1 nor is it ,h4 ,l4 ,smith's ,type ,no4 #ede1 which is ,s4 ulna var4 danica1 nor is it ,s4 biceps ,wm4 ,smith1 but it is exactly ,schmidt's form 7,atlas1 ,pl4 #cjc1 ,figs4 #aj-ae74 ,schuylkill ,river4 ,pl4 #aa1 ,fig4 #c4 ,,synedra ,,danica ,,kuetz4 ,valve lanceolate1 suddenly constricted at the rounded apices2 central space frequently absent4 ,very common in streams4 ,pl4 #aa1 ,fig4 #b4 ,the figure represents an unusually large form4 ,it differs from ,s4 ulna only in its apices4 ,,synedra ,,capitata ,,ehr4 ,valve long1 linear1 dilated into triangular acute apices2 pseudoraphe distinct2 stri radiate at the ends4 ,blue clay4 ,pl4 #aa1 ,fig4 #h4 ,,synedra ,,acus ,,kuetz4 ,valve very narrow1 lanceolate1 acicular1 with obtuse apices4 ,common in the ,schuylkill ,river4 ,pl4 #aa1 ,figs4 #i and #ah4 ,,synedra ,,goulardi ,,br,b4 ,valve constricted in the middle2 apices sub-acute1 sometimes slightly rostrate or capitate2 central space evident4 ,neshaminy ,creek 7,palmer74 ,blue clay4 ,crum ,creek4 ,pl4 #aa1 ,figs4 #ab and #ac4 ,,synedra ,,pulchella 7,,ralfs7 ,,kuetz4 ,valve lanceolate1 tapering to the sub-acute1 rostrate or slightly capitate apices2 dilated at the central hyaline space2 pseudoraphe distinct4 ,very variable in size4 ,crum ,creek4 ,schuylkill ,river4 ,rather common4 ,pl4 #aa1 ,figs4 #ad1 #ae1 #af4 ,,synedra ,,pulchella ,,var4 ,,abnormis ,,macchiati8 ,valve as in type form1 except that one end is curved like a beak1 as in ,s4 hamata ,wm4 ,sm41 which it resembles4 ,not uncommon in the ,schuylkill ,river4 ,pl4 #aa1 ,fig4 #ag4 ,,synedra ,,oxyrhynchus ,,var4 ,,undulata ,,grun4 ,valve linear-lanceolate with produced rostrate apices1 asymmetrical1 sigmoid2 pseudoraphe narrow2 pseudo-nodule large4 ,common in fresh water4 ,pl4 #ab1 ,fig4 #a4 #di,,synedra ,,pulchella ,,var4 ,,flexella ,n4 ,,var4 ,frustule slightly attenuated at the ends1 truncate1 somewhat tumid in the middle and flexed4 ,valve lanceolate1 with obtuse or subcapitate apices and with two almost imperceptible constrictions at the middle producing a tumid appearance2 pseudoraphe distinct2 pseudo-nodule absent4 ,l4 #ef 2 stri1 #ad-af in #aj 4 ,some valves are bent and incised on one side4 ,the outline of the valve is that of pulchella4 ,common at ,newtown ,square4 ,pl4 #ab1 ,fig4 #b4 ,,synedra ,,radians ,,kuetz4 ,frustules linear1 in small fasci4 ,valve #cd in length1 linear1 with apices rostrate1 obtuse1 sometimes slightly capitate2 pseudoraphe distinct2 stri about #bj in #aj 4 ,fresh water4 ,pl4 #aj1 ,figs4 #cb and #cc4 ,there is difficulty in recognizing ,s4 radians ,k4 as described and figured by different authors4 ,on ,plate #ab1 ,fig4 #h1 ,i have drawn a specimen from ,h4 ,l4 ,smith's ,type ,slide ,no4 #egd1 labelled ,s4 radians ,kuetz41 not ,wm4 ,smith1 which1 however1 corresponds closely to ,smith's figure 7,brit4 ,diat4 #a1 ,pl4 #aa1 ,fig4 #hi74 ,de ,toni gives ,s4 radians ,kuetz4 as equivalent to ,s4 tenera ,wm4 ,sm4 ,van ,heurck's figure of ,s4 radians1 and also the figure of ulna var41 said to be synonymous with ,h4 ,l4 ,smith's ,s4 radians1 which does not correspond to the specimens on ,smith's slide in my possession1 are confusing4 ,in ,van ,heurck's ,synopsis the stri are said to be #af or #ag1 while ,de ,toni describes them as subtle and from #ag to #bd in #aj 4 ,the length is quite variable4 ,several species of ,synedra resemble ,s4 radians in the mode of growth1 as they are adnate at first1 in short bands1 the frustules being sessile on other plants or objects1 attached at the terminal nodules which1 although scarcely visible in most forms1 are probably present in all4 ,the frustules are not closely connected at the free end1 and soon become entirely detached4 ,in ,diatoma and ,fragilaria1 we find a punctum or pore at one end of a valve1 but not in line with the pseudoraphe2 in ,synedra1 a minute pore is usually found in the position of the terminal nodule and1 in some species1 indications of a central nodule are observed2 the median line is wider but there is no raphe4 ,in the fresh-water ,synedr1 many of which are among the longest of diatoms1 living in running streams1 the terminal nodules are much more indistinct1 while the marine forms have distinct terminal nodules1 are not1 as a rule1 found in bands1 and assume a more naviculoid outline4 ,,synedra ,,vaucheri ,,var4 ,,parvula 7,,kuetz47 ,,rab4 ,valve lanceolate1 with produced or rostrate apices2 pseudo-nodule wide1 excentric4 ,l4 #ag 4 ,crum ,creek4 ,pl4 #ab1 ,fig4 #e4 ,fig4 #f represents a variety with coarser stri from the ,schuylkill ,river4 ,both are easily mistaken for ,fragilaria intermedia4 #ej,,synedra ,,fulgens 7,,grev47 ,,wm4 ,,sm4 ,frustules geminate or flabellate on a stipe4 ,valve slightly inflated in the middle and at the apices2 pseudoraphe narrow2 stri finely punctate1 radiate at the ends4 ,marine4 ,atlantic ,city4 ,pl4 #aa1 ,fig4 #aj4 ,,synedra ,,affinis ,,kuetz4 ,valve lanceolate2 stri marginal1 leaving a broad lanceolate pseudoraphe4 ,common along the coast4 ,pl4 #ab1 ,fig4 #c4 ,,synedra ,,affinis ,,var4 ,,parva 7,,kuetz47 ,v4 ,h4 ,valve lanceolate1 slender2 stri marginal1 shorter than in the type4 ,synedra gracilis ,kuetz4 ,common along the coast4 ,pl4 #ab1 ,fig4 #g4 ,,synedra ,,affinis ,,var4 ,,tabulata 7,,ag47 ,v4 ,h4 ,valve linear-lanceolate2 stri1 #aa in #aj 1 very short4 ,not common4 ,new ,rochelle4 ,pl4 #ab1 ,fig4 #d4 ,,asterionella ,,hassall 7#ahee7 7dim4 of aster1 a star7 ,frustules linear1 slightly inflated at the ends1 arranged in star-shaped clusters which soon break up4 ,valve linear1 unequally inflated at the ends4 ,,asterionella ,,formosa ,,hass4 ,valve clavate at the ends2 stri transverse1 #ag in #aj 1 pseudoraphe very narrow or indistinct2 an ovoid1 hyaline area at each end4 ,newark1 ,n4 ,j4 ,broomall's ,lake1 ,media 7,palmer74 ,pl4 #ab1 ,figs4 #ai1 #bj1 #ba4 ,,asterionella ,,inflata ,,heib4 ,valve linear1 capitate at each end and tumid in the middle2 stri distinctly punctate2 pseudoraphe indistinct1 or not apparent4 ,l4 #cj 4 ,fresh water4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ab1 ,fig4 #bb4 ,,eunotiin ,eunotia4--,frustules either free1 in fasci or epiphytic4 ,valves arcuate4 ,actinella4--,frustules1 solitary or in small clusters1 cuneate4 ,valve inflated at one end4 #ea;,,eunotia ,,ehr4 7#ahcg7 em4 ,,grun4 7#ahfb7 7eu1 well1 and noton1 a back1 referring to the strong1 ridged dorsum7 ,frustules free1 in fasci or epiphytic4 ,valve arcuate1 without cost1 transversely striated2 pseudoraphe absent2 pseudo-nodules at each end4 ,chromatophores laminate along the concave zone and the valves4 ,very many species of ,eunotia have been created to differentiate size and number of cren or undulations4 ,an examination of certain fossil deposits of ,new ,england1 as well as a gathering from the blue clay of ,philadelphia1 will show forms which vary infinitely4 ,e4 major and ,e4 gracilis are scarcely distinguishable because of the intermediate variations4 ,the stri in all forms are punctate1 but the puncta are frequently confluent4 ,,analysis ,,of ,,species ,eunotia is divided into two sections1 ,himantidium and ,eunotia proper4 ,in ,himantidium1 the frustules are in fasci1 either short or long4 ,among those with short fasci are major1 gracilis1 and nymanniana2 those with long fasci are pectinalis1 solierolii and veneris4 ,eunotia proper includes frustules1 free or epiphytic1 in which the valves are not dentate on the dorsal margin1 such as lunaris1 hemicyclus1 biceps and prrupta2 and those in which the valves are dentate or crenate on the dorsum1 such as monodon1 triodon1 diadema and others4 ,the resemblance between ,eunotia and ,epithemia is noticeable4 ,in both1 the epiphytic character of the valve is seen in the shape of the frustule which is arched1 and1 in the free forms1 is adherent at the ends only4 ,in ,epithemia1 the median is more evident than the terminal nodules4 ,in ,eunotia1 there is no median nodule1 but the end nodules1 in some species1 are quite evident1 and a tendency is shown to produce a very short raphe4 ,the arrangement of puncta in valve view is similar in both genera4 ,,section #a4 ,,himantidium ,,eunotia ,,major 7,,wm4 ,,sm47 ,,rab4 ,valve arcuate1 linear1 subcapitate1 recurved4 ,stri punctate1 #ab in #aj ,l4 #ij-aij 4 ,common in fresh water4 ,pl4 #ac1 ,figs4 #a and #b4 ,,eunotia ,,gracilis 7,,ehr47 ,,rab4 ,valve with sides parallel2 apices slightly capitate and revolute2 stri1 #aj in #aj 4 ,the stri on the connective membrane more delicate than in ,e4 major4 ,intermediate forms occur4 ,common in fresh water4 ,pl4 #ac1 ,fig4 #c4 ,fig4 #d is indeterminate4 ,,eunotia ,,nymanniana ,,grun4 ,valve small1 curved1 with parallel dorsal and ventral margins2 apices truncate and recurved into dorsal elevations2 stri delicate4 ,blue clay4 ,not common4 ,pl4 #ac1 ,fig4 #cb4 #eb;,,eunotia ,,pectinalis 7,,kuetz47 ,valve linear1 arcuate1 apices slightly rostrate2 stri distinctly punctate with puncta in longitudinal rows nearer together at the ends4 ,himantidium pectinale ,kuetz4 ,common in fresh water4 ,pl4 #ac1 ,figs4 #f and #g4 ,the fasci are associated in large masses1 sometimes an inch or more in diameter1 and late in ,august are found a foot or more in length1 of a beautiful chocolate color4 ,exceedingly abundant in the cedar-swamp streams of the ,pine ,barren regions of ,new ,jersey4 ,in winter1 the dead frustules form a parchment-like coating upon the twigs1 dead leaves1 and other dbris on the borders of streams4 ,this species can scarcely be referred to ,dillwyn's ,conferva pectinalis1 as1 in his description1 quoting ,mueller1 he says that the filaments are of a dirty green color2 seldom exceeding half an inch in length4 ,dillwyn's form is probably ,fragilaria virescens1 which equals ,fragilaria pectinalis ,ehr41 while ,kuetzing's species is ,fragilaria pectinalis ,ralfs4 ,it is not impossible to confuse ,fragilaria virescens and ,eunotia pectinalis when the zone only is seen under a low power and their mode of growth is similar4 ,,eunotia ,,pectinalis ,,var4 ,,undulata ,,ralfs ,valve as in type form1 but with undulate margins4 ,common in the cedar swamps of ,new ,jersey4 ,pl4 #ac1 ,figs4 #h and #aj4 ,,eunotia ,,pectinalis ,,var4 ,,solierolii 7,,kuetz47 ,valve as in type1 but with internal divisions as though in the process of reduplication4 ,not common4 ,moorestown1 ,n4 ,j4 7,palmer74 ,pl4 #ac1 ,fig4 #i4 ,,eunotia ,,pectinalis ,,var4 ,,ventricosa ,,grun4 ,as in type1 but with the valves tumid in the middle4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ac1 ,fig4 #ab4 ,fig4 #aa is a form found in the blue clay4 ,it differs in the coarser puncta from the var4 ventricosa4 ,in outline it resembles ,eunotia arcus ,wm4 ,sm41 which is ,ceratoneis arcus 7,ehr47 ,kuetz41 but the central nodule is not present as in the latter form1 which connects ,eunotia and ,cymbella4 ,it may be a form of ,e4 luna ,ehr4 7,a4 ,s41 ,atlas1 ,pl4 #bhf1 ,figs4 #cc and #cd47 ,,eunotia ,,veneris ,,kuetz4 ,valve with convex dorsal and straight ventral margins1 more or less constricted near the sub-acute apices4 ,stri subtle1 punctate4 ,eunotia incisa ,greg4 ,may's ,landing1 ,n4 ,j4 ,blue clay1 ,pavonia1 ,n4 ,j4 ,pl4 #ac1 ,figs4 #cj and #ca4 #ec;,,eunotia 7,,proper7 ,,eunotia ,,lunaris 7,,ehr47 ,,grun4 ,frustules sessile1 solitary or in clusters4 ,valve arcuate1 narrow1 attenuated toward the apices1 which are sometimes slightly rostrate or rostrate-capitate2 transverse stri1 #ad in #aj 1 punctate4 ,very common in ditches1 especially in the spring4 ,variable in length4 ,pl4 #ab1 ,figs4 #bd and #be4 ,,eunotia ,,hemicyclus 7,,ehr47 ,,ralfs ,valve semicircular1 with obtuse apices2 stri transverse1 punctate2 terminal nodules minute and indistinct4 ,hammonton ,pond1 ,n4 ,j4 ,rare4 ,pl4 #ab1 ,fig4 #bc4 ,the genus ,pseudo-,eunotia was created by ,grunow for forms like ,eunotia1 but without terminal nodules4 ,as1 however1 in ,e4 lunaris and ,e4 hemicyclus nodules are evident1 although not so large as in many species1 ,i include these two forms as heretofore under ,eunotia4 ,,eunotia ,,biceps ,,ehr4 ,valve linear1 slightly arcuate1 narrow1 with rounded apices somewhat revolute2 stri1 #af in #aj 4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ac1 ,fig4 #bg4 ,,eunotia ,,pr,,rupta ,,ehr4 ,valve convex on dorsal side1 apices dilated and truncate2 stri distant at centre4 ,common in the blue clay4 ,pl4 #ac1 ,fig4 #e4 ,,eunotia ,,pr,,rupta ,,var4 ,,bidens ,,grun4 ,valve with two undulations2 otherwise as in type4 ,eunotia bigibba ,greg4 ,with the type4 ,pl4 #ac1 ,fig4 #ai4 ,,eunotia ,,robusta ,,ralfs ,valve arcuate1 with several or numerous dorsal ridges or cren which decrease in relative size in proportion to their number4 ,stri radiate1 variable in distance apart1 and in size of puncta4 ,ralfs included under this one name the following species named by ,ehrenberg3 ,e4 diodon 7#b cren72 ,e4 triodon 7#c72 ,e4 tetraodon 7#d72 ,e4 pentodon 7#e72 ,e4 diadema 7#f72 ,e4 heptodon 7#g72 ,e4 octodon 7#h72 ,e4 enneadon 7#i72 ,e4 decadon 7#aj72 ,e4 hendecadon 7#aa72 ,e4 duodecadon 7#ab72 ,e4 serra 7#ac72 ,e4 prioritis 7#ad72 all more than #bj1 ,e4 polyodon4 ,e4 scalaris1 with from #ae to #ag cren1 and ,e4 icosodon with #bj1 may be added4 ,it is probable that all of these forms occur at ,may's ,landing1 ,n4 ,j4 ,the forms with more than eight cren are comparatively rare4 ,in the blue clay those with from four to six are most common4 ,pl4 #ac1 ,figs4 #ac1 #ad1 #ae1 #af1 #ag1 #ba1 #bd1 #be4 #ed;,,eunotia ,,bactriana ,,ehr4 ,valve linear1 apices revolute1 acute1 dentate on the dorsal margin1 with one acute crena near each end4 ,tom's ,river1 ,n4 ,j4 ,rare4 ,pl4 #ac1 ,fig4 #ah4 ,,eunotia ,,bidentula ,,wm4 ,,sm4 ,valve with straight ventral margin1 and with two undulations on the dorsum2 apices large1 rounded4 ,may's ,landing1 ,n4 ,j4 ,rare4 ,pl4 #ac1 ,fig4 #bj 7not ,schumann's form1 which has angular cren74 ,,eunotia ,,formica ,,ehr4 ,,var48 ,valve turgid in the middle and at the apices which are unilaterally truncate4 ,pensauken1 ,n4 ,j4 7artesian well74 ,pl4 #ac1 ,fig4 #bf 7not a typical form74 ,the following are forms which appear to be indeterminate1 or1 in any case1 are scarcely worthy of distinction by specific names1 as might be said of others of the innumerable variations of this genus3 ,fig4 #bc1 ,pl4 #ac1 probably a form of prrupta4 ,newtown ,square4 ,fig4 #bh1 ,pl4 #ac1 from the blue clay4 ,fig4 #bi1 ,pl4 #ac1 an asymmetrical form1 apparently abnormal1 but not rare at ,may's ,landing1 ,n4 ,j4 ,fig4 #ag1 ,pl4 #ch4 ,valve convex on the dorsal side1 incised on the ventral2 stri about #ae in #aj 1 closer at the ends2 ,l4 #cj 4 ,schuylkill ,river4 ,fig4 #ah1 ,pl4 #ch4 ,valve arcuate1 asymmetrical1 broader at one end2 terminal nodules large2 stri1 #aj in #aj 2 ,l4 #dg 4 ,gloucester1 ,n4 ,j41 artesian well4 ,numerous variations of the above species are illustrated in ,schmidt 7,atlas1 ,pls4 #bhe-bia74 ,,actinella ,,lewis 7#ahfe7 7dim4 of actin1 a ray7 ,frustules solitary1 or in small clusters1 sub-cuneate or nearly linear4 ,valve arcuate1 rounded at one end and suddenly widened at the other into a cup-shaped or lychnoid inflation4 ,,actinella ,,punctata ,,lewis ,valve with fine1 transverse stri2 on the margin1 puncta at intervals2 terminal nodules distinct4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ab1 ,figs4 #af1 #ag1 #ah4 ,fig4 #ag1 from ,tom's ,river1 ,n4 ,j41 is an approach toward ,a4 brasiliensis ,grun4 ,fig4 #ah represents the frustules geminate1 a frequent occurrence4 #ee,,naviculoide ,in discussing the ,naviculoid group1 the general divisions of ,cleve are here followed1 and all diatoms having a true raphe are included4 ,i have added the genus ,epithemia and also ,rhopalodia1 partly because they contain a raphe of a certain kind and partly because they resemble the markings of certain of the genus ,hantzschia in the following group1 although in other respects there is probably no similarity4 ,the difficulty of combining the numerous genera into groups which are naturally affiliated is avoided in the following arrangement based on superficial similarities1 and is intended merely as an artificial key4 ,to unite all forms having a raphe and which are symmetrical with valves similar and not sigmoid1 under the one genus ,navicula1 as has been the custom previous to the publication of ,cleve's monograph1 would result in associating species differing in so many respects in relation to structure of the valve and cell contents that it seems advisable to retain the new genera1 especially as the original genus is likely to be still further reduced when more is known of the structure and life history of the group4 ,,key ,,to ,,the ,,genera ,valves dissimilar4 ,achnanthe symmetrical ,cocconeis asymmetrical to the longitudinal axis ,anorthoneis to the transverse axis ,rhoicosphenia in zone view ,achnanthes ,valves similar and asymmetrical asymmetrical to the longitudinal axis valves parallel ,cymbella valves not parallel ,amphora valves keeled1 twisted 7sometimes symmetrical7 ,amphiprora valves keeled ,tropidoneis valves reniform and keeled ,auricula median line sigmoid at the ends ,scoliotropis asymmetrical to the transverse axis stri punctate and costate ,gomphoneis stri punctate ,gomphonema ,valves similar1 symmetrical and sigmoid stri oblique ,pleurosigma stri at right angles ,gyrosigma ,valves similar1 symmetrical1 not sigmoid stri punctate1 nodules elongated ,frustulia stri subtly punctate1 central nodule forked ,amphipleura stri punctate and reticulate1 in two strata ,dictyoneis stri punctate and alveolate1 in three strata ,trachyneis stri punctate1 in two strata ,brbissonia stri interrupted by blank lines ,anomoeoneis stri crossed by longitudinal lines ,caloneis stri oblique1 median fissures in opposite directions ,neidium stri punctate and costate1 median line with horns ,diploneis stri punctate2 valves separated by septate plates ,mastogloia stri punctate1 central area dilated into a stauros ,stauroneis stri punctate1 area without stauros or horns ,navicula stri costate1 not punctate ,pinnularia #ef;,,achnanthe ,frustules stipitate1 free or parasitic4 ,valves cuneate1 elliptical or suborbicular1 dissimilar1 bent along the transverse or the longitudinal axes1 the lower valve with a true raphe and central and terminal nodules1 the upper valve with a pseudoraphe or median line4 ,rhoicosphenia4--,stipitate2 valves with transverse puncta1 bent along the transverse axis1 cuneate1 with diaphragms at the ends4 ,anorthoneis4--,free2 puncta radiate2 valves bent slightly along the transverse axis1 suborbicular4 ,cocconeis4--,parasitic2 valves elliptical1 usually bent along the longitudinal axis2 stri punctate1 transverse and longitudinal4 ,achnanthes4--,stipitate2 valves lanceolate or elliptical1 bent along the transverse axis2 stri transverse1 punctate2 cost sometimes present4 ,,rhoicosphenia ,,grun4 7#ahfj7 7rhoicos1 curved1 and sphen1 a wedge7 ,frustule in zone view curved2 valves cuneate1 dissimilar1 the upper with a pseudoraphe1 the lower with a raphe4 ,chromatophore a single plate along both valves1 and one of the inner walls of the zone4 ,conjugation as in ,gomphonema1 with which it is generally associated in classification4 ,,rhoicosphenia ,,curvata 7,,kuetz47 ,,grun4 ,valve clavate1 with rounded apex and base2 lower valve with raphe1 a narrow axial area and slightly radiate1 punctate stri2 the upper valve with a narrow pseudoraphe and parallel stri2 a short diaphragm at the ends of each valve4 ,length usually from #ae to #be 1 but frequently of twice the size4 ,common in ,crum ,creek4 ,pl4 #ai1 ,figs4 #be1 #bf1 #bg4 ,,anorthoneis ,,grun4 7#ahfh7 7anorthos1 not straight7 ,valves dissimilar1 the upper valve with an excentric axial area1 the lower with an excentric raphe4 ,,anorthoneis ,,excentrica 7,,donk47 ,,grun4 ,valves orbicular1 with radiating1 punctate stri1 closer at the circumference1 producing the appearance of a border4 ,axial area not reaching the ends4 ,frustules occur free on the sands of the sea-shore4 ,l4 #be to #ej 4 ,belmar1 ,n4 ,j4 ,pl4 #af1 ,figs4 #cj and #ca4 #eg;,,cocconeis ,,ehr4 7#ahce7 em4 ,,grun4 7#ahfh7 7coccos1 a berry7 ,valves elliptical1 dissimilar1 the upper valve with a pseudoraphe and the lower with a genuine raphe and nodules1 usually with a rim or annulus4 ,frustules epiphytic4 ,cocconeis is generally considered as a degenerated form of ,mastogloia1 as indicated by the obsoletely loculiferous rim4 ,the frustules are usually bent along the longitudinal axis1 probably because of the attachment to the curved stems of water-plants4 ,the cell contents of only a few species are known4 ,in ,c4 pediculus1 a single chromatophore occurs on the inside of the upper valve4 ,in conjugation1 two cells open and secrete a gelatinous mass from which an auxospore is formed4 ,cleve separates the forms having a loculiferous rim 7,cocconeis7 from those without a rim 7,eucocconeis74 ,as the rim is easily detachable1 the distinction is often made with difficulty4 ,,cocconeis ,,scutellum ,,ehr4 ,valves elliptical1 the upper with a linear or lanceolate pseudoraphe and coarse puncta in transverse and radiating lines2 the lower valve with much finer puncta in radiating lines1 a lanceolate axial area and1 sometimes1 a loculiferous rim4 ,along the coast4 ,common1 but extremely variable4 ,pl4 #af1 ,fig4 #ba 7upper valve74 ,fig4 #ah1 var4 8 ,,cocconeis ,,scutellum ,,var4 ,,ornata ,,grun4 ,upper valve with linear axial area1 and transverse and radiating punctate lines which end at the border in a double row of finer puncta2 lower valve with much finer puncta1 a lanceolate axial area and a loculiferous rim4 ,atlantic ,city4 ,common4 ,pl4 #af1 ,figs4 #bg and #bh4 ,the forms along the coast vary infinitely both in size and appearance4 ,the var4 ornata is very abundant along the entire coast4 ,in any gathering1 valves are found with or without the rim which is frequently seen detached4 ,the upper valve is sometimes without the double row of puncta4 ,fig4 #ba represents an upper valve more coarsely punctate than usually occurs4 ,very many intermediate forms might be noticed4 ,,cocconeis ,,pediculus ,,ehr4 ,valves rhombic-elliptical1 very convex1 somewhat asymmetrical2 the upper valve with a linear pseudoraphe1 sometimes widened near the ends1 and slightly radiating1 finely punctate stri2 lower valve with narrow1 axial area and finely punctate1 radiating stri4 ,not uncommon in fresh water4 ,abundant in a ditch at ,paoli1 ,pa4 ,pl4 #af1 ,figs4 #bc and #bd4 ,,cocconeis ,,placentula ,,ehr4 ,valve elliptical2 upper valve with a linear or lanceolate axial area1 and punctate stri in transverse and radiating rows1 the puncta at equal distances2 the lower valve with a lanceolate axial area1 radiating rows of puncta1 and a wide border of finely punctate1 radiating stri1 separated from the central part of the valve by a narrow hyaline zone4 ,common in salt1 brackish and fresh water4 ,pl4 #af1 ,figs4 #ai and #bj4 #eh;,,cocconeis ,,placentula ,,var4 ,,lineata 7,,ehr47 ,v4 ,h4 ,as in the type1 except that the upper valve has the puncta arranged in zig-zag1 giving the appearance of sinuous1 longitudinal lines4 ,common along the coast4 ,pl4 #af1 ,fig4 #bi4 ,c4 pediculus and ,c4 placentula are the only species ,i have found in fresh water4 ,cleve states that the former occurs also in brackish water4 ,the following are among the species placed by ,cleve in a new genus1 ,eucocconeis1 distinguished by the absence of a loculiferous rim4 ,,cocconeis ,,dirupta ,,greg4 ,valves elliptical1 the lower with fine puncta in slightly radiating lines1 a narrow axial area and a central area dilated into a lanceolate1 stauriform space2 the terminal fissures turned in opposite directions2 the upper valve similar to the lower valve except in the absence of raphe and nodules4 ,along the coast4 ,new ,rochelle4 ,pl4 #af1 ,fig4 #bb 7lower valve74 ,,cocconeis ,,pellucida ,,grun4 ,valves elliptical1 the upper with broad axial area on each side of which are fine1 longitudinal rows of short stri2 the lower valve with more numerous longitudinal rows1 a marginal line and indistinct raphe2 the terminal fissures small and turned in opposite directions4 ,new ,rochelle4 ,pl4 #af1 ,figs4 #be and #bf4 ,in the var4 minor ,grun4 the median line of the lower valve is sometimes slightly sigmoid4 ,,achnanthes ,,bory 7#ahbb7 7achne1 froth or down1 and anthos1 a flower7 ,frustules stipitate1 solitary or in short fasci1 flexed4 ,valves elliptical or lanceolate1 naviculoid1 dissimilar1 the lower with a raphe and median and terminal nodules1 and the upper with a pseudoraphe or median space4 ,the genus has no apparent affinity with any other4 ,,achnanthes ,,longipes ,,ag4 ,valves linear-elliptical1 obtuse at the apex1 sometimes slightly constricted in the middle4 ,connective zone with transverse1 subtly punctate stri1 interrupted by longitudinal lines4 ,central nodule of lower valve dilated into a stauros reaching the margin4 ,valves costate1 the cost alternating with double rows of fine puncta4 ,along the coast1 in estuaries4 ,pl4 #af1 ,figs4 #a and #b4 ,a4 longipes is the only species in our locality considered by ,cleve as belonging to the genus2 the other forms1 distinguished by the absence of cost1 are included in the genus ,achnanthidium of ,kuetzing4 ,in ,a4 longipes1 the chromatophores consist of scattered1 rounded granules1 while in ,achnanthidium the chromatophore is a single plate along the upper valve1 or a double one #ei;along the connective zone4 ,it is necessary1 therefore1 to distinguish between ,a4 longipes and the following group1 but1 because of the long continued union of all of the stipitate forms having the general appearance of a true ,achnanthes1 ,i shall continue to describe the local species under the generally accepted name4 ,,achnanthes ,,brevipes ,,ag4 ,valves without cost2 stri moniliform2 upper valve with excentric pseudoraphe or median line2 otherwise as in ,a4 longipes4 ,along the coast1 in estuaries4 ,pl4 #af1 ,fig4 #c4 ,,achnanthes ,,subsessilis ,,kuetz4 ,valves linear-elliptical1 rounded at the ends2 upper valve with excentric pseudoraphe2 stri moniliform1 puncta smaller than in ,a4 brevipes4 ,along the coast1 in estuaries4 ,pl4 #af1 ,figs4 #d1 #e1 #f4 ,the three species described above are named from the length of the stipe1 but this varies considerably and is not of special significance4 ,,achnanthes ,,inflata 7,,kuetz47 ,,grun4 ,valves more or less inflated in the middle1 usually with the stauros of the lower valve asymmetrical and wider than in ,a4 subsessilis1 with which it agrees in size and markings4 ,gloucester1 ,n4 ,j4 7artesian well74 ,pl4 #af1 ,figs4 #g and #h4 ,,achnanthes ,,coarctata 7,,br,b47 ,,grun4 ,valves lanceolate1 oblong1 broad at the ends and constricted in the middle4 ,stauros wide2 pseudoraphe of the upper valve excentric2 stri slightly radiate on the lower valve2 puncta small4 ,blue clay4 ,pl4 #af1 ,fig4 #i4 ,,achnanthes ,,lanceolata 7,,br,b47 ,,grun4 ,valves more or less elliptical2 stri radiating1 #ab in #aj 1 punctate2 on the lower valve a horse-shoe shaped hyaline space on one side of the centre2 on the upper valve an irregular stauros1 not reaching the margin4 ,l4 #h-bj 4 ,in springs4 ,abundant at ,newtown ,square4 ,pl4 #af1 ,figs4 #aj1 #aa1 #ab4 ,,achnanthes ,,exigua ,,grun4 ,valves oblong-lanceolate1 with rostrate ends1 sometimes slightly constricted in the middle4 ,stauros rather wide2 stri punctate1 radiating1 #bb in #aj 4 ,l4 #aj-ab 4 ,stauroneis exilis ,kuetz4 7not ,achnanthes exilis ,kuetz47 ,frequently found in aquaria where ,i have kept it growing continuously for years4 ,pl4 #af1 ,figs4 #ad and #ae4 ,,achnanthes ,,linearis ,,forma ,,curta ,h4 ,l4 ,,smith ,frustules solitary or geminate4 ,valves linear-elliptical1 or elliptical-lanceolate4 ,lower valve without distinct axial area2 upper valve with axial area widened in the middle2 stri slightly radiate 7874 ,l4 #g 4 ,one of the smallest of diatoms4 #fj,this form ,i found in a pure gathering covering the sides of a greenhouse tank at ,elm1 ,n4 ,j4 ,it was sent to ,prof4 ,h4 ,l4 ,smith1 who determined it as forma curta of ,a4 linearis4 ,pl4 #af1 ,figs4 #af and #ag4 ,,achnanthes ,,danica 7,,floegel7 ,,grun4 ,valves rhombic-lanceolate1 with subacute ends4 ,stri1 #be in #aj 1 radiate4 ,lower valve with stauros widened toward the margin1 and cleft into three divisions4 ,pavonia1 ,n4 ,j4 7artesian well74 ,pl4 #af1 ,fig4 #ac4 ,i have seen the lower valve only4 ,cleve states that the upper valve is costate with alternating fine lineol twice as close as the cost4 ,,cymbella ,,ag4 7#ahcj7 7cymbe1 a boat7 ,frustules free1 stipitate or enclosed in tubes4 ,valve boat-shaped2 median line asymmetrical1 straight or curved4 ,chromatophore single1 covering the entire interior of the frustule1 except the ventral part of the zone and the median lines4 ,its longitudinal axis is on the dorsal part of the zone4 ,a pyrenoid lies in a fold of the chromatophore on the dorsal part4 ,the genus includes the former genera of ,cocconema1 characterized by stipitate forms1 and ,encyonema in which the frustules are frequently enclosed in gelatinous tubes4 ,,section #a4--;,,cymbella ,,proper4 ,,frustules ,,free ,,or ,,sometimes ,,stipitate ,,cymbella ,,heteropleura 7,,ehr47 ,,kuetz4 ,valve nearly symmetrical1 lanceolate1 with rostrate1 produced apices2 median line nearly straight2 axial area linear1 widened in the middle2 stri radiate1 punctate4 ,blue clay4 ,pl4 #ah1 ,fig4 #aj4 ,,cymbella ,,cuspidata ,,kuetz4 ,valve broad1 elliptical1 with rostrate1 somewhat acute1 apices and nearly straight1 ventral margin2 median line straight1 axial area linear1 widened in the middle2 stri radiate1 punctate4 ,blue clay4 ,pl4 #ah1 ,fig4 #ag4 ,,cymbella ,,naviculiformis ,,auerswald ,valve linear-elliptical1 with abruptly produced apices2 ventral margin straight2 median line almost straight2 axial area narrow1 central area large1 rounded2 stri distant in the middle1 closer at the ends4 ,fresh water4 ,pl4 #ah1 ,fig4 #f4 ,,cymbella ,,ehrenbergii ,,kuetz4 ,valve lanceolate1 with ventral margin nearly straight and apices sub-rostrate2 median line straight1 excentric2 axial area narrow2 central area widened in the middle2 stri coarsely punctate4 ,fresh water4 ,pl4 #ah1 ,fig4 #i4 #fa;,,cymbella ,,affinis ,,kuetz4 ,valve about three times as long as broad1 strongly convex on the dorsal side and straight on the ventral2 apices sub-rostrate2 stri punctate2 axial area narrow1 not widened in the middle2 median line curved2 a small or indistinct punctum on the ventral side of the median line 7not shown in the figure74 ,common in ponds4 ,abundant in ,east ,park ,reservoir4 ,pl4 #ah1 ,fig4 #ah4 ,,cymbella ,,excisa 7,,kuetz47 ,,de ,,toni ,valve as in affinis1 but with tumid and excised ventral margin2 a punctum is found on the ventral side 7not shown in the figure74 ,according to ,cleve this is a variety of ,c4 affinis4 ,common in ponds4 ,pl4 #ah1 ,figs4 #ae1 #ai8 ,,cymbella ,,parva 7,,wm4 ,,sm47 ,,cl4 ,valve semi-lanceolate1 with produced apices2 ventral margin slightly tumid2 axial area narrow2 stri coarsely but obscurely punctate4 ,c4 affinis and ,c4 parva are quite variable1 the latter differing by its lanceolate form and the absence of a punctum1 which1 however1 is sometimes difficult to recognize4 ,in a gathering of ,c4 parva1 it is quite possible to find numerous abnormal forms which appear to be sporangial1 so that specific distinctions are difficult if based on occasional specimens4 ,common in ponds4 ,pl4 #ch1 ,fig4 #ad4 ,,cymbella ,,amphicephala ,n,,geli ,valve unequally elliptical1 with broad1 rostrate apices2 axial area narrow2 median line straight2 central area small1 rounded2 stri1 #ab in #aj on the dorsal1 closer on the ventral1 side and at the ends4 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #ah1 ,fig4 #af4 ,,cymbella ,,sinuata ,,greg4 ,valve linear-elliptical1 gibbous on the ventral side2 axial area indistinct2 central area widened on the ventral side nearly to the margin4 ,crum ,creek4 ,pl4 #ah1 ,fig4 #ac4 ,,section #b4--;,,cocconema4 ,,frustules ,,stipitate ,,cymbella ,,aspera 7,,ehr47 ,,cl4 ,valve large1 cymbiform1 arcuate on the dorsal1 slightly gibbous on the ventral side2 axial area linear1 broad1 slightly widened in the middle2 no row of puncta on the ventral side4 ,the puncta form curved longitudinal lines and the innermost row on the ventral side appears sometimes distant from the others1 but not as in ,c4 cistula4 ,cocconema asperum ,ehr4 ,cymbella gastroides ,kuetz4 #fb,not ,cymbella gastroides ,h4 ,l4 ,smith1 ,type ,no4 #aah1 which is ,c4 mexicana ,a4 ,s41 having a punctum in the middle of the central nodule2 in outline it is like ,c4 gastroides var4 minor ,kuetz4 ,blue clay4 ,pl4 #ah1 ,fig4 #a 7an unusual form1 but it resembles ,grunow's4 7,diat4 ,franz ,jos4 ,land1 ,pl4 #a1 ,fig4 #g47 ,,cymbella ,,cymbiformis 7,,kuetz47 ,,br,b4 ,valve cymbiform1 slightly gibbous on the ventral margin2 apices broad1 somewhat truncate2 a punctum occurs on the ventral side of the median line2 stri1 #h in #aj 1 closely punctate4 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #ah1 ,fig4 #b4 ,,cymbella ,,cistula 7,,hempr47 ,,kirchn4 ,valve cymbiform1 with gibbous ventral margin and truncate apices2 a distinct row of several puncta occurs below the median line in typical forms4 ,blue clay4 ,pl4 #ah1 ,fig4 #c4 ,,cymbella ,,lanceolata 7,,ehr47 ,,kirchn4 ,valve cymbiform1 with gibbous ventral margin2 apices truncate2 axial area very narrow1 scarcely widened in the middle2 stri with fine close puncta4 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #ah1 ,fig4 #d4 ,,cymbella ,,mexicana 7,,ehr47 ,a4 ,s4 ,valve broad1 with gibbous ventral margin and sub-rostrate1 truncate apices2 median line with reflexed terminal fissures2 stri with coarse puncta2 a large punctum occurs in the centre of the central area4 ,blue clay4 ,pl4 #ah1 ,fig4 #e4 ,,cymbella ,,tumida 7,,br,b47 ,v4 ,h4 ,valve cymbiform1 with gibbous ventral margin and abruptly rostrate ends2 median line arcuate2 axial area narrow2 central area large1 orbicular2 below the central nodule is a punctum2 stri punctate4 ,crum ,creek4 ,pl4 #ah1 ,fig4 #g4 ,,section #c4--;,,encyonema4 ,,frustules ,,in ,,tubes ,,cymbella ,,ventricosa ,,kuetz4 ,valve lunate1 with straight or slightly gibbous ventral margin2 axial area indistinct2 median line straight or nearly so2 stri punctate4 ,very common1 but extremely variable4 ,the ventral margin is sometimes straight and sometimes quite gibbous4 ,pl4 #ah1 ,figs4 #ad1 #bb2 ,pl4 #ch1 ,fig4 #af2 ,pl4 #dj1 ,fig4 #h4 #fc;,c4 ventricosa is considered by some authors to be equivalent to ,c4 affinis var4 semicircularis ,lagerst41 ,encyonema prostratum 7,berk47 ,ralfs1 ,e4 cspitosum ,kuetz4 and ,e4 auerswaldii ,rab4 ,h4 ,l4 ,smith's ,type ,slide of ,c4 ventricosa ,ag4 is said to equal ,c4 affinis ,kuetz41 but the specimens appear to me to be equivalent to ,c4 ventricosa ,kuetz4 ,cleve unites many forms1 including ,e4 cspitosum1 under ,c4 ventricosa4 ,,cymbella ,,prostrata 7,,berk47 ,,cl4 ,valve semi-elliptical1 obtuse at the apices1 which are sometimes prolonged and turned downwards2 median line straight1 terminal nodules distant from the ends2 axial area narrow1 central area rounded2 stri in radiating1 slightly curved lines1 indistinctly punctate4 ,common in fresh water2 occasional in brackish4 ,pl4 #ah1 ,fig4 #ba 7represents a frequent variation74 ,,cymbella ,,philadelphica ,n4 ,,sp4 ,valve semi-elliptical-lanceolate1 with rounded apices2 ventral margin strongly gibbous2 terminal nodules distant from the ends2 axial area broad1 central area widened on the dorsal side2 stri radiate1 not curved nor of unequal length1 indistinctly punctate1 #aj in #aj on the dorsal1 #h in #aj on the ventral side4 ,l4 #hf 4 ,this form approaches ,encyonema prostratum 7,berk47 ,ralfs1 ,schmidt's ,atlas1 ,pl4 #ga1 ,fig4 #g1 but differs in the stri and the axial and central areas4 ,blue clay of ,philadelphia4 ,rare4 ,pl4 #ah1 ,fig4 #h4 ,,cymbella ,,triangulum 7,,ehr47 ,,cl4 ,valve semi-elliptical1 with acute ends2 median line straight2 ventral side half the width of the dorsal1 with straight1 slightly convex or concave margin2 stri radiate1 coarsely punctate4 ,gloeonema triangulum ,ehr4 ,baker's ,run1 ,willistown1 ,pa4 ,pl4 #ah1 ,fig4 #bd4 ,,cymbella ,,turgida 7,,greg47 ,,cl4 ,valve semi-elliptical1 with acute ends2 ventral margin gibbous2 ventral side half the width of the dorsal2 median line straight2 terminal fissures turned downwards2 axial area broad2 stri radiate1 coarsely punctate4 ,baker's ,run1 ,willistown1 ,pa4 ,pl4 #ah1 ,fig4 #bc4 ,,cymbella ,,turgida 7,,greg47 ,,cl4 ,,var4 8 ,valve lunate1 with gibbous ventral margin2 median line straight2 terminal fissures turned downwards near the ends2 axial area lanceolate1 stri radiate on the dorsal side1 #h in #aj 1 punctate1 #i on the ventral side1 closer at the ends where they are convergent4 ,l4 #fe 4 ,not a typical form4 ,willistown1 ,pa4 ,pl4 #ah1 ,fig4 #ab4 ,,cymbella ,,rhomboidea ,n4 ,,sp4 ,valve rhomboidal1 with acute ends2 dorsal part one and a half times the width of the ventral2 median line nearly straight1 with terminal fissures turned downwards near the ends2 axial area broad1 not widened in the middle1 except slightly on the ventral side2 stri #fdradiate1 distant in the middle of the dorsal side where they are #g in #aj 1 coarsely punctate1 the puncta in longitudinal lines1 #i in #aj on the ventral side1 closer at the ends4 ,l4 #fi 4 ,baker's ,run1 ,willistown1 ,pa4 ,pl4 #ah1 ,fig4 #aa4 ,,cymbella ,,gracilis 7,,rab47 ,,cl4 ,valve semi-lanceolate1 with acute ends2 median line nearly straight1 with terminal fissures turned downwards1 distant from the ends2 axial area linear2 ventral margin straight or slightly gibbous in the middle4 ,hammonton ,pond1 ,n4 ,j4 ,pl4 #ah1 ,fig4 #bj4 ,,cymbella ,,lacustris 7,,ag47 ,,cl4 ,valve elliptical-lanceolate1 with obtuse ends1 nearly symmetrical2 median line straight1 terminal fissures distant from the ends2 stri radiate in the middle1 convergent at the ends1 coarsely lineate4 ,belmar1 ,n4 ,j4 ,pl4 #ah1 ,fig4 #be4 ,,amphora ,,ehr4 7#ahdj7 7amphora1 a jar7 ,valves asymmetrical along the longitudinal axis1 as in ,cymbella1 but with the plane passing through the dorsal and ventral sides of one valve at an angle with that of the other4 ,as ,cleve states1 ,cymbella and ,amphora are forms of ,navicula with both valves similar and asymmetrical along the longitudinal axis1 and the difference between ,cymbella and ,amphora is in the degree of asymmetry4 ,if1 following ,h4 ,l4 ,smith's diagrams 7,lens1 ,vol4 #b1 #ahgc1 p4 #ff71 we assume that the usual form of the valve in ,navicula is elliptical or lanceolate1 and the zone view is rectangular1 we have in ,cymbella an arcuate median line and a more or less reniform valve1 while the zone view remains rectangular with the valves parallel4 ,now1 if the valves are asymmetrical along the longitudinal axis1 and one side of one valve is separated from the corresponding side of the opposite valve by a wider connective zone than is the case on the other side1 the transverse section of the frustule will appear cuneate1 as in ,amphora1 and the connective zone will be wider on one side than the other4 ,when1 therefore1 we examine an entire frustule as it is usually seen1 we shall find the two raphes of the valves in focus at the same time on the ventral side1 and1 by changing the focus1 the convex sides of the same valves are seen1 the dorsal view with1 usually1 a wider connective zone4 ,as an illustration1 compare ,figs4 #e and #f1 on ,plate #ae1 ,fig4 #f being the ventral1 and ,fig4 #e the dorsal view4 ,as ,amphor are epiphytic or parasitic1 they are considered1 as ,cleve remarks1 like ,achnanthes and ,cocconeis1 as degenerated forms4 ,chromatophores usually single1 lying on the ventral connective zone4 ,mereschkowsky describes nine forms4 ,cleve divides the genus into a number of groups as follows3 ,amphora proper4--,connective zone not complex2 valves with longitudinal lines on the dorsal side2 coarsely punctate or costate4 ,diplamphora4--,zone complex2 otherwise as in ,amphora4 ,halamphora4--,longitudinal lines absent2 frustule elongate1 with protracted ends4 #fe,oxyamphora4--,zone complex2 longitudinal lines absent2 frustule elliptical2 valve lunate1 with or without a central stauros2 stri punctate4 ,amblyamphora4--,zone complex2 frustule rectangular2 valve lunate2 stri punctate2 axial and central areas indistinct4 ,psammamphora4--,zone not complex2 frustule rectangular2 central nodule frequently dilated to a stauros2 no axial or central area4 ,cymbamphora4--,valve semi-lanceolate2 median line straight1 approximate to the ventral margin4 ,,amphora ,,amphora ,,robusta ,,greg4 ,frustule elliptical1 truncate2 valve lunate1 with straight ventral margin2 median line biarcuate2 ventral side with coarse1 radiate stri1 #f in #aj 1 on both sides of the median line4 ,along the coast4 ,pl4 #ae1 ,fig4 #a4 ,,amphora ,,proteus ,,greg4 ,frustule elliptical1 truncate2 valve lunate1 with straight ventral margin2 median line biarcuate2 no central area4 ,stri on the dorsal side not interrupted1 #i in #aj 4 ,ventral side striate toward the ends4 ,differs from ,a4 robusta chiefly in size and coarseness of puncta4 ,extremely variable in size4 ,common along the coast4 ,pl4 #ae1 ,figs4 #e1 #f1 and #ai4 ,,amphora ,,ovalis 7,,br,b47 ,,kuetz4 ,frustule elliptical1 truncate2 valve lunate2 median line biarcuate2 stri on dorsal side #aj-af in #aj 4 ,var4 libyca 7,ehr47 ,cl4--,central area distinct on the dorsal side4 ,var4 pediculus 7,kuetz47 ,cl4--,central area and nodule quite distinct4 ,stri finer than in var4 libyca4 ,common in ponds4 ,quite variable4 ,pl4 #ae1 ,fig4 #g4 ,,amphora ,,gigantea ,,var4 ,,fusca ,a4 ,s4 ,frustule elliptical2 valve lunate1 with straight ventral margin4 ,axial area absent on the dorsal side2 dorsal stri1 #aj in #aj 1 punctate4 ,ventral part hyaline except at the ends1 which are obliquely striated1 with short1 punctate lines4 ,l4 #gj-abj 4 ,absecon1 ,n4 ,j4 ,pl4 #ch1 ,fig4 #a4 ,,diplamphora ,,amphora ,,crassa ,,greg4 ,valve linear-elliptical1 with obtuse1 incurved ends4 ,median line biarcuate4 ,axial and central areas indistinct on the dorsal side2 stri coarsely punctate1 interrupted by a longitudinal line on the dorsal side4 ,along the coast4 ,pl4 #ae1 ,fig4 #c4 #ff;,,amphora ,,areolata ,,grun4 ,valve with straight ventral margin2 median line straight1 approximate to the ventral margin2 axial area indistinct2 several longitudinal lines crossed by apparent cost which alternate with rows of fine puncta4 ,blue clay4 ,rare4 ,pl4 #ae1 ,fig4 #aa4 ,,halamphora ,,amphora ,,coff,,iformis 7,,ag47 ,,kuetz4 ,frustule lanceolate1 truncate2 zone with numerous divisions4 ,valve arcuate on the dorsal and nearly straight on the ventral side2 ends protracted or slightly capitate4 ,a4 aponina ,kuetz4 ,a4 salina ,wm4 ,sm4 ,along the coast4 ,pl4 #ae1 ,figs4 #h and #ah4 ,,oxyamphora ,,amphora ,,lineolata ,,ehr4 ,frustule membranaceous1 elliptical1 truncate1 with broad ends4 ,zone with numerous divisions4 ,dorsal part striated transversely2 ventral side with longitudinal lines4 ,a4 plicata ,greg4 ,a4 hyalina ,h4 ,l4 ,smith1 ,type ,no4 #fd4 ,along the coast4 ,pl4 #ae1 ,figs4 #i and #aj4 ,,amphora ,,ostrearia ,,br,b4 ,frustule oblong1 with rounded angles4 ,zone with five or more divisions transversely striated4 ,central area narrow1 biarcuate2 central nodule dilated to a stauros4 ,valve narrow1 with arcuate dorsal and straight ventral margin1 acute at the ends4 ,stri transverse1 finely punctate4 ,a4 vitra ,cl42 ,a4 porcellus ,kitton2 ,a4 quadrata ,brb42 ,a4 elegans ,greg4 ,appearance varies according to the position of the valve4 ,along the coast4 ,pl4 #ae1 ,figs4 #ab and #ba4 ,,amphora ,l,,vis ,,greg4 ,frustule oblong1 hyaline and membranaceous4 ,valve linear or slightly arcuate1 with ventral margin tumid in the middle2 ends obtuse2 central nodule dilated to a stauros2 median line very narrow1 biarcuate1 coinciding with the dorsal margin at the ends2 stri transverse1 punctate4 ,blue clay4 ,pl4 #ae1 ,fig4 #ac4 ,,amphora ,,acuta ,,greg4 ,valve lunate1 with acute ends2 ventral margin straight2 ventral side very narrow4 ,central nodule dilated to a stauros2 stri transverse1 punctate4 ,along the coast4 ,pl4 #ae1 ,fig4 #bj4 #fg;,,amblyamphora ,,amphora ,,obtusa ,,greg4 ,frustule rectangular4 ,valve linear1 obliquely rounded at the ends1 with arcuate dorsal1 and straight ventral1 margin2 median line biarcuate2 stri1 #ah-bj in #aj 4 ,along the coast4 ,common4 ,pl4 #ae1 ,fig4 #d4 ,,psammamphora ,,amphora ,,arenaria ,,donk4 ,frustule hyaline1 rectangular1 slightly tumid in the middle1 with rounded angles4 ,valve linear with broad ventral side and straight or sinuate ventral margin4 ,stri1 #bd-bg in #aj 7,cleve74 ,common along the coast4 ,pl4 #ae1 ,fig4 #ag4 ,the distinction between ,a4 obtusa and ,a4 arenaria is not always evident if the valves alone are seen4 ,the former has a complex zone1 the latter a simple zone1 and the valve has finer stri4 ,cleve's descriptions and references in regard to these two forms do not agree with the descriptions and figures of ,h4 ,l4 ,smith1 or with the figures of ,schmidt4 ,the valves of most ,amphor are capable of assuming various outlines according to their position4 ,,amphora ,,ocellata ,,var4 ,,cingulata ,,cleve ,frustule rectangular4 ,valve linear1 with dorsal margin arcuate and the ventral margin straight4 ,central nodule with a stauros on the dorsal side4 ,squan ,river1 ,n4 ,j4 ,pl4 #ae1 ,figs4 #ad and #ae4 ,,cymbamphora ,,amphora ,,angusta ,,var4 ,,eulensteinii ,,grun4 ,valve lanceolate1 acute at the ends4 ,median line straight1 approximate to the margin4 ,axial area widened on the dorsal side1 indistinct on the ventral2 stri punctate4 ,a4 eulensteinii ,a4 ,s4 ,common along the coast4 ,pl4 #ae1 ,fig4 #af4 ,on ,pl4 #dj1 ,figs4 #ba1 #bb1 and #bc1 ,i have attempted1 imitating ,h4 ,l4 ,smith's figures 7,lens1 l4c471 to illustrate the difference in the transverse sections of ,navicula1 ,cymbella and ,amphora4 ,fig4 #ba represents the transverse section of a convex ,navicula1 in which the valves ecg and fdh are parallel1 and the median nodules c and d are central4 ,fig4 #bb is a transverse section of ,cymbella in which the valves are nearly parallel and the median nodules are excentric4 ,the girdles on one side1 ea and af1 are narrower than gb and bh on the other side4 ,fig4 #bc is a transverse section of an ,amphora in which the valves appear in zone view with the median nodules of both valves on the same side4 ,the girdles on the ventral side1 ea and af1 are narrower than gb and bh on the dorsal side4 ,the girdles on the dorsal side are seldom as broad as gb and bh1 the valve extending over a great part of the dorsal side to g' and h'4 #fh;,,amphiprora ,,ehr4 7#ahdc7 7amphi1 on both ends1 and prora1 a prow7 ,frustule twisted in the longitudinal axis1 constricted in the middle2 zone complex1 with numerous divisions crossed by fine stri4 ,valve lanceolate1 acute4 ,the raphe confined within a sigmoid keel or extension of the valve2 the central and terminal nodules indistinct4 ,stri transverse1 punctate1 with coarser stri at the junction of the keel and lower part of the valve4 ,chromatophores single1 with indented border except in ,a4 pulchra1 in which there are two chromatophores with entire borders4 ,,amphiprora ,,alata ,,kuetz4 ,frustule with a row of puncta at the junction line4 ,valve linear1 acute at the ends4 ,median line sigmoid4 ,stri lineate on the lower part of the valve1 punctate on the keel4 ,along the coast4 ,not common4 ,pl4 #ad1 ,fig4 #c4 ,,amphiprora ,,pulchra ,,bail4 ,frustule with sigmoid connective zone4 ,valve very convex1 with sinuate keel and junction lines evident4 ,in zone view and in valve view1 one half of the frustule1 owing to the elevation of the keel1 is wider than the other half4 ,stri punctate1 coarser on the keel4 ,not uncommon along the coast4 ,pl4 #ad1 ,figs4 #a and #b4 ,,amphiprora ,,conspicua ,,grev4 ,valve linear or elliptical1 with acute ends4 ,median line sigmoid1 but the junction lines not evident4 ,stri lineate1 with coarser lines near the middle4 ,not common4 ,port ,penn1 ,delaware ,river4 ,pl4 #ad1 ,fig4 #d4 ,,amphiprora ,,ornata ,,bail4 ,frustule membranaceous1 constricted in the middle1 with well-marked folds extending from the junction line in both directions4 ,valve lanceolate1 constricted in the middle and with protracted ends4 ,keel undulate on the edge4 ,a beautiful1 transparent and delicate form1 the only fresh-water species in our locality4 ,delaware ,water ,gap1 ,pa4 ,pl4 #ad1 ,figs4 #f and #g4 ,,amphiprora ,,paludosa ,,wm4 ,,sm4 ,frustule membranaceous1 constricted1 with truncate ends4 ,valve linear1 with acute ends4 ,stri scarcely visible4 ,cape ,may 7,cleve74 ,pl4 #ad1 ,fig4 #e4 ,,tropidoneis ,,cleve 7#ahia7 7tropis1 a keel7 ,frustule oblong1 constricted in the middle2 keel not sigmoid4 ,axial area not evident4 ,stri very fine1 punctate1 in longitudinal lines4 #fi,,tropidoneis ,,lepidoptera 7,,greg47 ,,cleve ,valve with straight1 median excentric line4 ,keel unilateral1 projecting above the median line in zone view2 central area small4 ,transverse stri finely punctate4 ,as usually seen1 the valve is inclined4 ,according to ,karsten there are two chromatophores on the connective zone1 each divided into four parts1 each of which contains a large oval pyrenoid4 ,amphiprora lepidoptera ,greg4 ,along the coast4 ,pl4 #ad1 ,figs4 #h and #i4 ,,auricula ,,castracane 7#ahgc7 7auricula1 the ear1 the shape of the valve7 ,frustule globose4 ,valve reniform or cymbiform1 elevated into a keel which is not sigmoid4 ,median line biarcuate4 ,differs from ,amphiprora in not having a sigmoid keel4 ,,auricula ,,mucronata 7,h4 ,l4 ,,smith7 ,,peragallo ,in zone view1 the median line deeply bisects the longitudinal axis1 ending in a mucronate central nodule4 ,connective zone complex4 ,valve very complex1 with ventral margin nearly straight and raphe excentric4 ,central nodule near the margin1 terminal nodules small4 ,stri1 #ce-dj in #aj 7,cleve74 ,chromatophore single1 on the ventral part4 ,amphora mucronata ,h4 ,l4 ,smith4 ,amphora 787 insecta ,grun4 ,auricula insecta 7,grun47 ,cleve4 ,a rare and very curious pelagic species 7,peragallo1 ,diat4 ,villefranche74 ,prof4 ,h4 ,l4 ,smith included this form in his first century of ,species ,typic ,diatomacearum1 which was issued prior to #ahgf1 the date of publication1 in ,schmidt's ,atlas1 of ,amphora insecta ,grun4 ,atlantic ,city1 ,n4 ,j4 ,rare4 ,pl4 #ae1 ,fig4 #b4 ,,scoliotropis ,,cleve 7#ahid7 7scolios1 twisted1 and tropis1 a keel7 ,frustule linear1 oblong4 ,median line sigmoid near the ends4 ,valve with transverse cost alternating with two intermediate rows of puncta in oblique lines4 ,,scoliotropis ,,latestriata ,,var4 ,,amphora ,,cleve ,valve asymmetrical1 with the median line curved4 ,frustule sub-acute at the ends4 ,median lines not on the same side of each valve of the frustule4 ,abundant at ,cape ,may1 ,n4 ,j4 ,not common elsewhere4 ,pl4 #ad1 ,figs4 #aj and #aa4 ,,gomphoneis ,,cleve 7#ahid7 7gomphos1 a peg1 and neis 7naus77 ,valve elongated1 asymmetrical to the transverse axis2 axial area narrow2 central area rounded1 stigmatic2 stri radiating1 cost alternating with double rows of fine puncta4 ,an indistinct1 longitudinal line near the border4 ,chromatophores and conjugation have not been determined4 #gj;,,gomphoneis ,,herculaneum 7,,ehr47 ,,cl4 ,valve clavate1 with rounded apex2 cost1 #ac in #aj 1 alternating with double rows of fine puncta1 #bb in #aj 1 in oblique rows2 axial area narrow1 central area rounded1 with one stigma4 ,gomphonema capitatum ,ehr var4 herculaneum ,ehr41 ,h4 ,l4 ,s41 ,type ,slide ,no4 #agg4 ,common in the blue clay4 ,pl4 #ai1 ,fig4 #b4 ,pl4 #ch1 ,fig4 #ae1 zone view of young frustule4 ,,gomphoneis ,,mamilla 7,,ehr47 ,,cl4 ,valve lanceolate1 with rounded apex and base2 stri costate1 #aj in #aj 1 alternating with double rows of fine puncta2 axial area linear1 sometimes oblique1 central area small1 with one or more stigmas4 ,blue clay4 ,rare4 ,pl4 #ai1 ,fig4 #a4 ,in one frustule ,i noticed one valve with one stigma and the other with four stigmas4 ,the difference between ,g4 mamilla and ,g4 elegans is not very great4 ,in the latter the central area is larger and the longitudinal lines not so near to the margin4 ,the stigmas form a circlet4 ,there appears to be a coincidence in the relation of ,gomphoneis to ,gomphonema1 and that of the true ,achnanthes to the group described by ,cleve under ,achnanthidium4 ,in ,gomphoneis and ,achnanthes the striation is both costate and punctate while in ,gomphonema and ,achnanthidium the striation is punctate only4 ,,gomphonema ,,ag4 7#ahbd7 7gomphos1 a peg1 and nema1 a filament7 ,valve elongated1 asymmetrical with respect to the transverse axis2 stri transverse1 usually radiate1 punctate4 ,chromatophore band single1 the middle lying on one zone4 ,in conjugation1 according to ,thwaites and ,pfitzer1 from two mother cells1 which do not form a positive union1 two auxospores are developed parallel to the original frustules4 ,in ,plate #ai1 ,fig4 #ai1 ,i have drawn a representation of the auxospore formation as ,i have frequently observed it in a gathering sent me by ,mr4 ,t4 ,c4 ,palmer1 containing ,g4 angustatum1 a common species in this locality4 ,the sagittal plane of the valve of the auxospore is at right angles to the plane of the valve of the mother cell4 ,two valves of one of the mother cells are seen separated1 one on each side of the auxospore which is nearly twice the length of the original frustules4 ,the two valves of the other mother cell are not shown as they are not usually found closely united4 ,in the figure one valve alone of the auxospore is seen1 the opposite valve not being in focus4 ,the valves of the auxospore are usually more or less arcuate1 as in ,cymbella1 to which the genus is closely allied4 ,grunow divides ,gomphonema into two groups1 ,asymmetric and ,symmetric1 according to the presence or absence of stigmas4 ,cleve suggests ,stigmatic and ,astigmatic as more suitable in order to agree with the ,cymbell4 ,the ,stigmatic are found chiefly in fresh water1 sometimes in brackish4 ,all of the marine forms belong to the ,astigmatic1 which1 however1 include some common fresh-water forms4 ,many species of ,gomphonema are stipitate1 some occur in gelatinous masses1 and others are free4 #ga;,,gomphonema ,,montanum ,,schum4 ,valve slightly biconstricted1 with obtuse apex and basis1 somewhat cuneate2 axial area linear1 widened in the middle unilaterally2 stigma1 one2 stri about #aa in #aj 1 more distant in the middle1 punctate4 ,gomphonema subclavatum var4 montana 7,schum47 ,cl4 ,pavonia1 ,n4 ,j41 artesian well4 ,rare4 ,pl4 #ai1 ,fig4 #c4 ,,gomphonema ,,geminatum ,,lyng4 ,valve biconstricted1 with large1 rounded1 sub-truncate apex and broad1 sub-truncate basis2 stri1 #i in #aj 1 radiate in the middle1 alternately longer and shorter1 transverse at the basis and near the apex where they again radiate1 coarsely punctate1 puncta1 #ab in #aj 4 ,axial area linear2 central area rounded1 with several large stigmas in a longitudinal row2 terminal fissures hook-shaped4 ,blue clay4 ,pl4 #ai1 ,fig4 #d4 ,,gomphonema ,,lanceolatum ,,var4 ,,insignis 7,,greg47 ,,cl4 ,valve lanceolate2 axial area narrow2 central area unilateral with one stigma2 stri with coarse and distant puncta4 ,common and variable4 ,gomphonema insigne ,greg4 ,pl4 #ai1 ,figs4 #f and #ab4 ,fig4 #ab shows a unilateral central area4 ,fig4 #f is more clavate in outline with small central area4 ,in both forms the coarse puncta are in distinct longitudinal lines in the middle4 ,,gomphonema ,,acuminatum ,,var4 ,,turris 7,,ehr47 ,,cl48 ,valve clavate1 with cuneate1 acute apex2 axial area distinct2 central area unilateral with one stigma4 ,blue clay4 ,pl4 #ai1 ,fig4 #aa4 ,,gomphonema ,,acuminatum ,,var4 ,,turris 7,,ehr47 ,,cl4 ,valve clavate1 with cuneate apiculate apex and narrow basis2 axial area narrow1 with a unilateral central space2 stigma opposite the short stri2 stri more radiate in the upper part1 distant in the middle4 ,smith's ,island1 ,delaware ,river4 ,pl4 #ai1 ,fig4 #e4 ,,gomphonema ,,acuminatum ,,var4 ,,coronata 7,,ehr47 ,,cl4 ,valve twice constricted1 with broad1 cuneate apex2 stri radiate in the middle1 convergent near the apex and radiate at the apex4 ,variable in size and outline4 ,blue clay4 ,fresh water4 ,common4 ,pl4 #ai1 ,fig4 #g4 ,,gomphonema ,,acuminatum ,,var4 ,,trigonocephala 7,,ehr47 ,,cl4 ,valve broad1 with cuneate apex2 axial area narrow2 central area unilateral with one stigma4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #ai1 ,fig4 #bj4 #gb;,,gomphonema ,,constrictum ,,ehr4 ,valve clavate1 constricted beneath the abruptly rounded apex1 gibbous in the middle1 stri alternately longer and shorter2 axial area narrow1 central area unilateral1 with one stigma4 ,common in fresh water4 ,pl4 #ai1 ,fig4 #h4 ,,gomphonema ,,sph,,rophorum ,,ehr4 ,valve clavate1 with capitate or rostrate-capitate apex and narrow basis2 axial area very narrow2 central area small1 unilateral1 with one stigma4 ,common in fresh water4 ,pl4 #ai1 ,figs4 #i and #aj4 ,fig4 #aj appears to be a transitional form having a more distinct axial area and rostrate apex4 ,,gomphonema ,,augur ,,ehr4 ,valve broadly clavate1 truncate and apiculate at the apex2 basis sub-acute2 axial area distinct2 central area small1 unilateral with one stigma2 stri with distant puncta4 ,blue clay4 ,willistown1 ,pa4 ,pl4 #ai1 ,fig4 #ba4 ,,gomphonema ,,intricatum ,,kuetz4 ,valve narrow1 lanceolate1 slightly gibbous in the middle2 axial area distinct2 central area transverse with one stigma2 stri parallel4 ,quite variable4 ,common in fresh water4 ,pl4 #ai1 ,fig4 #ad4 ,,gomphonema ,,angustatum ,,kuetz4 ,valve lanceolate1 with sub-rostrate apex and basis2 axial area indistinct2 central area unilateral1 with one small stigma2 stri slightly radiate1 indistinctly punctate4 ,very common in fresh water4 ,pl4 #ai1 ,figs4 #ah and #ai4 ,fig4 #ai1 as stated above1 represents the formation of an auxospore4 ,,gomphonema ,,quale ,,greg4 ,valve linear-lanceolate1 nearly symmetrical1 with capitate apex and basis2 axial area narrow2 central area unilateral1 with one stigma2 stri radiate in the middle1 slightly convergent at the ends4 ,gomphonema intricatum var4 quale 7,greg47 ,cl4 ,blue clay4 ,not common4 ,pl4 #ai1 ,fig4 #ae4 ,,gomphonema ,,sarcophagus ,,greg4 ,valve linear1 irregular in outline1 with rounded apex and basis2 axial area distinct2 central area small1 unilateral1 with one stigma2 stri irregular with coarse1 distinct puncta4 ,occasional in fresh water4 ,pl4 #ai1 ,fig4 #af4 ,,gomphonema ,,capitatum ,,ehr4 ,valve clavate1 broad at the sub-truncate apex and slightly constricted1 or with parallel margins2 axial area linear1 central area stellate1 with one stigma2 stri in the middle alternately longer and shorter4 ,blue clay4 ,pl4 #ai1 ,fig4 #bb4 #gc;,,gomphonema ,,parvulum ,,var4 ,,micropus 7,,kuetz47 ,,cl4 ,valve clavate1 with rounded apex and basis2 axial area indistinct2 central area unilateral1 with a small stigma2 stri distant in the middle4 ,common4 ,pl4 #ai1 ,fig4 #ag4 ,,gomphonema ,,ventricosum ,,greg4 ,valve clavate1 with broad apex and produced1 rounded basis2 axial area narrow1 widened in the middle2 stigma one2 stri distant in the middle1 finely punctate4 ,blue clay4 ,pl4 #ai1 ,fig4 #ac4 ,,gomphonema ,,olivaceum ,,lyng4 ,valve clavate1 with broad apex and narrow basis2 axial area very narrow2 central area irregular1 without stigma2 stri radiate1 finely punctate4 ,very common4 ,pl4 #ai1 ,fig4 #bc4 ,,gomphonema ,,brasiliense ,,var4 ,,demerar ,,grun48 ,valve lanceolate1 with sub-cuneate apex and narrowed basis2 axial area lanceolate1 broad2 no stigma2 median fissures remote2 stri parallel1 #ab in #aj 1 punctate1 the puncta obsolescent1 small or interrupted4 ,willistown1 ,pa4 ,rare4 ,pl4 #ai1 ,fig4 #bd4 ,,pleurosigma ,,wm4 ,,sm4 7#aheb7 7pleura1 a side1 and sigma1 the letter s7 ,valve lanceolate1 sigmoid2 axial area very narrow1 central area small2 stri punctate1 in transverse and oblique lines4 ,cleve divides the forms usually known as ,pleurosigma into two genera1 ,pleurosigma and ,gyrosigma4 ,pleurosigma includes all forms having oblique rows of puncta1 while ,gyrosigma includes all having longitudinal rows4 ,both have transverse stri4 ,the former consists entirely of marine species1 while in the latter the species are found in fresh1 brackish and salt water4 ,the endochrome in ,pleurosigma1 according to ,mueller1 consists of two bands which differ in the median part of each valve4 ,mereschkowsky says that the endochrome is so divided as to form four bands1 two on each valve1 that their position is different in different species1 and that they are not the same on valves of the same frustule4 ,cleve prefers to classify the species of ,pleurosigma and ,gyrosigma in accordance with the outline of the valve and the flexure of the median line4 ,i shall1 however1 retain the method used by ,peragallo and ,grunow and arrange the forms according to the striation4 7#a7 ,,oblique ,,stri ,,about #ij ,,degrees1 ,,more ,,distinct ,,than ,,the ,,transverse ,,pleurosigma ,,formosum ,,wm4 ,,sm4 ,valve elongated1 slender1 gently sigmoid1 acute at the ends2 oblique stri crossing each other at about #ij degrees2 #aj-af in #aj 2 transverse stri1 #ad-bj in #aj 7,cleve74 ,along the coast4 ,pl4 #bb1 ,fig4 #e4 #gd,,pleurosigma ,,obscurum ,,wm4 ,,sm4 ,valve linear1 not sigmoid1 or scarcely so2 ends obtuse1 subconical2 raphe sigmoid1 near the margin at the extremities2 transverse and oblique stri equidistant1 #bh in #aj 7,wm4 ,sm474 ,abundant at ,greenwich ,point1 ,philadelphia4 ,pl4 #bb1 ,fig4 #d4 7#b7 ,,oblique ,,stri ,,closer ,,at ,,the ,,ends ,,pleurosigma ,,naviculaceum ,,br,b4 ,valve lanceolate1 slightly sigmoid at the extremities2 raphe strongly sigmoid near the margin at the ends2 central nodule large1 rounded2 oblique stri1 #ac-ad in the middle1 closer at the ends2 transverse stri1 #ah-bj in #aj 7,peragallo74 ,long ,island ,sound4 ,pl4 #bb1 ,fig4 #f4 ,,pleurosigma ,,virginiacum ,h4 ,l4 ,,smith ,valve slightly sigmoid1 with acute ends2 raphe more sigmoid than the valve1 excentric near the ends2 oblique stri in different directions at the centre1 #ac in #aj 1 closer and less distinct at the ends2 central nodule small but prominent because of its thickness1 producing by diffraction an apparently wide area 7somewhat exaggerated in the figure74 ,l4 #ie 1 usually larger4 ,p4 affine var4 fossilis ,grun4 7,peragallo74 ,p4 normanii var4 fossilis ,grun4 7,cleve74 ,common in the blue clay4 ,pl4 #bb1 ,fig4 #h4 7#c7 ,,oblique ,,stri #fj ,,degrees ,,pleurosigma ,,angulatum 7,,quekett7 ,,cl4 ,valve rhomboidal1 with sub-rostrate or produced ends2 central nodule rhomboidal2 raphe central2 transverse and oblique stri at an angle of #fj degrees1 equidistant1 #ah-bb in #aj 4 ,navicula angulata ,quekett4 ,along the coast4 ,pl4 #bb1 ,fig4 #c4 ,,pleurosigma ,,strigosum ,,wm4 ,,sm4 ,valve lanceolate1 with sub-acute1 somewhat revolute1 apices2 oblique stri at an angle of about #fj degrees1 otherwise as in angulatum4 ,along the coast4 ,not common4 ,pl4 #bb1 ,fig4 #a4 ,,pleurosigma ,,stuarii ,,br,b4 ,valve lanceolate1 with produced apices2 raphe less sigmoid than the valve and excentric2 oblique stri1 #ai-ba in #aj 1 at an angle of about #fj degrees4 ,along the coast4 ,common4 ,pl4 #bb1 ,fig4 #g4 #ge7d7 ,,oblique ,,stri #fj ,,degrees1 ,,the ,,transverse ,,more ,,distant ,,pleurosigma ,,rigidum ,,wm4 ,,sm4 ,valve nearly straight or slightly sigmoid1 with obtuse ends2 raphe central1 excentric near the ends2 oblique stri1 #ag-ba1 transverse1 #af-ai in #aj 4 7,peragallo74 ,new ,rochelle1 ,n4 ,y4 ,pl4 #bb1 ,fig4 #b 7very near the var4 gigantea ,grun47 ,,gyrosigma ,,hassall 7#ahde7 7gyros1 curved1 and sigma7 ,valve lanceolate1 sigmoid2 axial area very narrow1 central area small2 stri punctate1 in transverse and longitudinal rows4 ,chromatophores two1 in long and narrow bands1 perforated1 differing from those of ,pleurosigma4 ,the eloplasts are also arranged differently in the two genera4 7,mereschkowsky1 tudes sur l',endochrome des ,diatomes1 ,imperial ,academy of ,petrograd1 #aija1 ,vol4 #aa1 ,no4 #f1 p4 #ah et seq47 ,the arrangement is according to ,peragallo4 7#a7 ,,longitudinal ,,stri ,,more ,,distant ,,than ,,the ,,transverse ,,gyrosigma ,,hippocampus 7,,ehr47 ,valve lanceolate1 sigmoid1 with obtuse ends2 raphe nearly central2 transverse stri #ae-ag1 longitudinal1 #aj-ab in #aj 4 ,navicula hippocampus ,ehr4 ,pleurosigma hippocampus 7,ehr47 ,wm4 ,sm4 ,gyrosigma attenuatum 7,kuetz47 ,cl4 ,long ,island ,sound4 ,pl4 #bc1 ,fig4 #c4 7#b7 ,,longitudinal ,,and ,,transverse ,,stri ,,nearly ,,equal ,,gyrosigma ,,balticum 7,,ehr47 ,,cl4 ,valve with margins parallel nearly to the extremities1 which are suddenly unilaterally sub-conical and obtuse2 raphe sigmoid2 transverse and longitudinal stri nearly equally distant1 #ae in #aj 7,per474 ,l4 #bjj-cfj 4 ,navicula baltica ,ehr4 ,pleurosigma balticum 7,ehr47 ,wm4 ,sm4 ,common along the coast4 ,pl4 #bc1 ,fig4 #b4 ,,gyrosigma ,,parkeri ,,var4 ,,stauroneioides ,,grun4 ,valve lanceolate1 slightly sigmoid1 ends produced into beaks with sub-acute apices2 raphe straight in the middle part2 central nodule elliptical2 transverse stri1 #ba1 and longitudinal1 #bd in #aj 7,per474 ,an apparent stauros1 variable in width1 extends to the margin and1 in consequence1 the median transverse stri are more evident4 ,l4 #ge 4 ,schuylkill ,river4 ,rather rare4 ,pl4 #bc1 ,fig4 #g4 #gf;,,gyrosigma ,,simile 7,,grun47 ,valve slightly sigmoid1 broad1 with obtuse ends2 raphe sigmoid1 nearly central2 transverse stri1 #ae1 longitudinal1 #af-ag in #aj 7,per474 ,pleurosigma simile ,grun4 ,gyrosigma balticum var4 similis 7,grun47 ,cl4 ,shark ,river1 ,n4 ,j4 ,pl4 #bc1 ,fig4 #d4 7#c7 ,,transverse ,,stri ,,more ,,distant ,,gyrosigma ,,acuminatum 7,,kuetz47 ,,cl4 ,valve sigmoid1 tapering to the sub-acute ends2 raphe central2 transverse and longitudinal stri nearly equally distant1 #ag or #ah in #aj 7,per474 ,frustulia acuminata ,kuetz4 ,port ,penn1 ,delaware ,river4 ,pl4 #bc1 ,fig4 #e4 ,,gyrosigma ,,strigilis 7,,wm4 ,,sm47 ,,cl4 ,valve sigmoid1 with obtuse ends2 raphe doubly sigmoid2 axial area rather wide2 transverse stri1 #ac1 and longitudinal1 about #af in #aj 4 ,long ,island ,sound4 ,not common4 ,pl4 #bc1 ,fig4 #a4 ,,gyrosigma ,,kuetzingii 7,,grun47 ,,cl4 ,valve sigmoid1 lanceolate1 with sub-acute ends2 raphe central1 the central nodule elliptical2 transverse stri1 #ba-bc1 and longitudinal1 #be-bf in #aj 4 ,pleurosigma spencerii var4 acutiuscula ,grun4 ,pleurosigma spencerii var4 kuetzingii ,grun4 ,common in fresh water4 ,pl4 #ch1 ,fig4 #ab4 ,,gyrosigma ,,scalproides 7,,rab47 ,,cl4 ,valve slightly sigmoid1 with obtuse ends2 raphe nearly straight2 central nodule elliptical2 transverse stri1 #bb1 slightly radiate and more distant in the middle2 longitudinal stri1 #bi in #aj 4 ,l4 #fj 4 ,common in streams4 ,pl4 #ch1 ,fig4 #i4 ,in ,pl4 #bc1 ,fig4 #f represents a form more sigmoid4 ,,gyrosigma ,,spencerii ,,var4 ,,nodifera ,,grun4 ,valve sigmoid1 with obtuse ends2 raphe central2 central nodule obliquely elongated2 transverse stri1 #ag-ah in #aj 1 curved in the middle of the valve1 longitudinal stri1 #bb in #aj 4 ,l4 #aej 4 ,blue clay4 ,pl4 #bc1 ,fig4 #h4 ,,gyrosigma ,,prolongatum 7,,wm4 ,,sm47 ,,cl4 ,valve narrow1 lanceolate1 produced into beaks1 curved in a contrary direction2 raphe central2 transverse stri1 #bj-ba in #aj 1 longitudinal closer4 ,l4 #adj 4 ,along the coast1 northward4 ,pl4 #ch1 ,fig4 #ac4 ,i have not seen any specimens south of ,new ,england1 but they will probably occur4 #gg7d7 ,,stri ,,alike1 ,,extremities ,,produced ,,gyrosigma ,,fasciola 7,,ehr47 ,,cl4 ,valve lanceolate1 attenuated into curved beaks turned in opposite directions2 raphe central1 straight1 except at the beaks2 transverse stri1 #bb1 longitudinal1 #bd in #aj 7,per474 ,new ,york ,bay4 ,pl4 #bc1 ,fig4 #i4 ,,frustulia ,,ag4 7#ahbd72 em4 ,,grun4 7#ahfe7 7frustulum1 a small piece7 ,valves naviculoid1 similar1 usually free but sometimes enclosed in gelatinous tubes or embedded in mucus4 ,median line between two thickened ribs4 ,central and terminal nodules frequently elongated4 ,surface of valve with fine puncta in longitudinal and transverse lines appearing hyaline under medium powers4 ,chromatophores1 two1 extending along the girdle4 ,they differ from those of ,navicula in being separated from the wall in the middle by a hemispherical mass of protoplasm4 ,according to ,pfitzer1 each chromatophore is divided in the middle1 allowing a connection between the hemispherical mass and the central plasma mass4 ,schmitz states that the chromatophore is thickened in the middle and contains a pyrenoid4 ,in conjugation1 two frustules form two cylindrical bodies which later become conical and from which are formed the sporangial valves twice the usual size4 ,,frustulia ,,lewisiana 7,,grev47 ,,de ,,toni ,valve elliptical or linear1 with rounded ends2 terminal nodules elongated1 at a distance from the ends2 stri1 #bd in #aj 4 ,port ,penn1 ,delaware ,river4 ,along the coast4 ,pl4 #ag1 ,fig4 #a4 ,,frustulia ,,rhomboides 7,,ehr47 ,,de ,,toni ,valve lanceolate or rhombic-lanceolate1 rounded at the ends2 central and terminal nodules short2 stri1 #bj in #aj 1 sometimes coarser4 ,common in fresh water4 ,pl4 #ag1 ,fig4 #b4 ,,frustulia ,,rhomboides ,,var4 ,,amphipleuroides ,,grun4 ,valve rhombic-lanceolate2 central and terminal nodules elongated2 median line somewhat excentric4 ,blue clay4 ,pl4 #ag1 ,fig4 #c4 ,,frustulia ,,rhomboides ,,var4 ,,saxonica 7,,rab47 ,,de ,,toni ,valve smaller than in rhomboides1 with somewhat produced ends1 closer median ribs and rounded central nodule4 ,fresh water4 ,pl4 #ag1 ,fig4 #f4 ,,frustulia ,,vulgaris 7,,thwaites7 ,,de ,,toni ,valve elliptical-lanceolate1 with rounded or sometimes sub-rostrate ends2 central and terminal nodules slightly elongated2 stri delicate1 closer at the ends4 ,frustules at first in gelatinous tubes4 ,colletonema vulgaris ,thwaites4 ,fresh water4 ,pl4 #ag1 ,fig4 #d4 #gh;,,frustulia ,,interposita 7,,lewis7 ,,de ,,toni ,valve linear-elliptical1 rounded at the ends2 terminal nodules short4 ,navicula interposita ,lewis4 ,along the coast4 ,port ,penn1 ,delaware ,river4 ,pl4 #ag1 ,fig4 #e4 ,,amphipleura ,,kuetz4 7#ahdd7 7amphi1 on both sides1 pleura1 a side7 ,frustules free1 in gelatinous masses or in tubes4 ,valve linear-lanceolate2 central nodule narrow1 extending half the length of the valve or more1 then forking toward the ends4 ,terminal nodules prolonged1 as in ,frustulia1 into a porte-crayon-shaped figure4 ,chromatophores two1 very short4 ,,amphipleura ,,pellucida ,,kuetz4 ,frustules free or in mucous masses4 ,valve fusiform2 forks about one-fourth the length of the valve2 stri transverse1 punctate1 #cf-dj in #aj 7,j4 ,j4 ,woodward74 ,occasional in the ,delaware ,river4 ,pl4 #ag1 ,fig4 #i4 ,,amphipleura ,,rutilans 7,,trentepohl7 ,,cl4 ,frustules enclosed in gelatinous tubes4 ,valve linear-lanceolate1 obtuse at the ends2 forks about one-third the length of the valve2 stri1 #bh in #aj 4 ,conferva rutilans ,trentepohl4 ,schizonema dillwynii ,wm4 ,sm4 ,abundant at ,belmar1 ,n4 ,j4 ,pl4 #ag1 ,fig4 #aj4 ,fig4 #aa represents a portion of the gelatinous tube containing frustules4 ,,dictyoneis ,,cleve 7#ahij7 7dictyon1 a net7 ,frustules oblong4 ,valve lanceolate1 constricted in the middle 7in our species72 an outer layer finely punctate and an inner layer of reticulations2 the margin of the valve divided into large1 quadrate cells4 ,the genus ,dictyoneis includes species at one time ascribed to ,mastogloia and ,navicula4 ,the structure1 however1 is not like that of either1 as the loculi are attached to the valve and are not separable as in ,mastogloia1 and the cell-wall is not like that of any ,navicula4 ,cleve remarks that ,dictyoneis is found in warm waters4 ,lewis found one specimen at ,black ,rock ,harbor1 ,l4 ,i41 and one in the ,delaware ,river blue clay4 ,the specimens here described ,i found living on the ,new ,jersey coast4 ,,dictyoneis ,,marginata ,,var4 ,,typica ,,cleve ,valve panduriform1 with cuneate lobes2 axial area narrow1 linear1 scarcely1 or not at all1 widened in the middle2 terminal fissures in contrary directions2 outer stratum finely punctate1 about #be in #aj 1 in parallel stri2 inner stratum coarsely reticulated4 ,four and one-fourth times longer than broad2 marginal cells1 #e in #aj 1 smaller or obsolescent in the middle of the valve2 cells of the valve in irregular transverse rows1 #aj-ab in #aj 4 ,l4 #ic 4 ,navicula marginata ,lewis4 ,absecon1 ,n4 ,j4 ,pl4 #bj1 ,fig4 #c4 #gi;,,dictyoneis ,,marginata ,,var4 ,,commutata ,,cleve ,valve four and one-half times longer than broad2 cells of the valve in irregular1 transverse rows about #aa in #aj 2 marginal cells nearly equal1 #f in #aj 4 ,l4 #abe 4 ,absecon1 ,n4 ,j4 ,pl4 #bj1 ,fig4 #b4 ,,dictyoneis ,,marginata ,,var4 ,,maxima ,n4 ,,var4 ,valve with cuneate segments2 marginal cells1 #d in #aj 2 cells of the valve1 #e in #aj 1 obsolescent in the middle and smaller2 transverse stri1 #be in #aj 4 ,atlantic ,coast4 ,rare4 ,pl4 #bj1 ,fig4 #a 7from a specimen found at ,colon74 ,,trachyneis ,,cleve 7#ahid7 7trachys1 rough1 and neis 7naus71 named from the chief species7 ,valve more or less linear or linear-lanceolate4 ,it appears to be composed of three strata1 one an interior1 coarsely dotted1 an exterior of fine puncta in longitudinal stri1 scarcely visible1 and a median of transverse anastomosing cost forming irregular alveoli4 ,chromatophores1 two or four bands on the zone 7,mereschkowsky74 ,,trachyneis ,,aspera ,,var4 ,,intermedia ,,grun4 ,valve linear-elliptic2 axial area a stauros widened outward and unilateral4 ,stri of the median layer of radiating rows of oblong alveoli4 ,along the coast4 ,not common4 ,pl4 #ag1 ,fig4 #ae4 ,the type form and its numerous varieties are quite ubiquitous4 ,very large specimens occur in the ,antarctic regions1 especially in material from ,ross ,island1 ,s4 ,victoria ,land 7,shackleton ,ant4 ,exp474 ,,br,,bissonia ,,grun4 7#ahfj7 7named after ,alphonse de ,brbisson1 the distinguished ,french naturalist7 ,frustules stipitate2 valve lanceolate2 stri transverse in the middle1 radiate at the ends4 ,median area narrow1 central nodule elongated1 terminal fissures at a distance from the ends4 ,valve with an outer finely punctate stratum4 ,at one end of one valve in each frustule is found a conspicuous punctum1 the plasma pore of ,otto ,mueller1 through which the frustule is connected with the gelatinous stipe1 analogous to the pore in ,diatoma connecting the zig-zag frustules4 ,chromatophore single1 lying on one girdle and passing over to each valve4 ,,br,,bissonia ,,boeckii 7,,kuetz47 ,,grun4 ,valve lanceolate1 with sub-acute apices2 stri1 #c-d in #aj 1 not reaching the median line4 ,blue clay4 ,very rare4 ,common in brackish water at ,chestertown1 ,md4 7,t4 ,c4 ,palmer7 ,pl4 #ag1 ,fig4 #g4 #hj;,,br,,bissonia ,,palmerii1 ,n4 ,,sp4 ,valve rhombic-lanceolate1 with cuneate ends and produced apices4 ,central nodule more elongate and terminal fissures further from the ends than in ,b4 boeckii4 ,pavonia1 ,n4 ,j4 7artesian well1 depth of #dj ft474 ,rare4 ,pl4 #ag1 ,fig4 #h4 ,i take pleasure in naming this species after ,mr4 ,t4 ,chalkley ,palmer1 of ,media1 ,pa41 the author of numerous papers on the ,diatomace4 ,lewis partly describes a similar form1 which he does not name1 as a species of ,navicula found in the blue clay at ,kaighn's ,point1 ,n4 ,j4 7,lewis1 ,new and ,intermediate ,forms1 etc41 p4 #ae1 ,pl4 #a1 ,fig4 #h47 ,,anomoeoneis ,,pfitzer 7#ahga7 7anomoios1 unlike1 and neis 7naus71 a boat7 ,valve lanceolate1 axial area narrow1 central area widened2 transverse stri punctate1 the puncta in longitudinal rows or interrupted by blank lines4 ,a single chromatophore lies along one of the girdle sides and extends over the valves1 each of the two parts being deeply notched or slit at the ends4 ,according to ,schmitz there are two pyrenoids1 but ,heinzerling thinks there is but one4 ,cleve considers this genus not well founded1 as it is based upon the cell contents of but one species1 the structure of the other species not being known4 ,as the forms here described are easily recognized by the interrupted puncta1 the genus is1 at least1 convenient4 ,,anomoeoneis ,,sph,,rophora 7,,kuetz47 ,,cl4 ,valve elliptic-lanceolate1 ends rostrate-capitate4 ,axial area narrow1 central area rounded1 larger on one side of the median line than the other4 ,stri very slightly radiate1 #af in #aj 1 punctate1 the puncta interrupted by longitudinal blank lines4 ,pfitzer states that the central plasma mass is unequal on the two sides4 ,navicula sphrophora ,kuetz4 ,fresh and brackish water4 ,not common4 ,pl4 #dj1 ,fig4 #b4 ,,anomoeoneis ,,serians 7,,br,b47 ,,cl4 ,valve lanceolate1 acute2 axial area lanceolate2 stri1 #bd in #aj 2 puncta elongate4 ,not common in this locality1 but abundant northwards2 fossil in the peat deposits of ,new ,england4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ag1 ,fig4 #ab4 ,forma minor--,valve rhombic-lanceolate1 smaller than the type4 ,may's ,landing1 ,n4 ,j4 ,pl4 #ag1 ,fig4 #ac4 ,,anomoeoneis ,,follis 7,,ehr47 ,,cl4 ,valve rhomboid1 tumid in the middle and obtuse at the produced ends4 ,central area lanceolate2 stri radiate in the middle1 transverse at the ends4 ,navicula follis ,ehr4 ,navicula trochus ,kuetz4 #ha,reported by ,lewis as very rare in the blue clay of the ,delaware ,river4 ,i have not seen it in this locality4 ,the figure is drawn from a specimen in the ,w4 ,bridgewater1 ,mass41 deposit4 ,pl4 #ag1 ,fig4 #ad4 ,,caloneis ,,cleve 7#ahid7 7calos1 beautiful7 ,valve convex1 linear or lanceolate in general outline1 with transverse1 smooth or finely punctate stri crossed by one or more longitudinal lines4 ,endochrome of two chromatophores lying one on each valve1 entire in some species and deeply cleft in others4 ,,caloneis ,,liber 7,,wm4 ,,sm47 ,,cl4 ,valve linear1 with parallel margins and rounded ends2 axial area narrow1 central area orbicular2 stri transverse in the middle1 slightly divergent at the ends1 #af in #aj 2 terminal fissures slightly curved in the same direction2 longitudinal line median4 ,l4 #hb 4 ,atlantic coast1 chiefly southward4 ,pl4 #dj1 ,fig4 #a4 ,,caloneis ,,silicula 7,,ehr47 ,,cl4 ,valve linear1 gibbous in the middle1 with broad sub-cuneate ends2 axial area narrow1 central area rounded2 longitudinal line marginal2 stri parallel or nearly so1 #af to #ah in #aj 4 ,navicula silicula ,ehr4 ,navicula limosa ,donk4 ,blue clay4 ,pl4 #ba1 ,fig4 #c 7var4 genuina ,cl474 ,,caloneis ,,silicula ,,var4 ,,inflata 7,,grun47 ,,cl4 ,valve gibbous in the middle1 with rounded ends2 central area elliptical4 ,schuylkill ,river4 ,pl4 #ba1 ,fig4 #d4 ,c4 silicula may be recognized by its yellow color when dry4 ,its varieties are extremely numerous4 ,,caloneis ,,trinodis 7,,lewis7 ,valve divided into three segments of equal width2 ends cuneate and usually produced2 axial area elliptical with a lunate marking on each side2 stri radiate in the middle1 elsewhere parallel1 about #bj in #aj 1 finely punctate2 longitudinal line marginal1 scarcely visible2 the stri become fainter toward the axial area4 ,occasional in streams and in the blue clay4 ,abundant in a water-trough at ,ashbourne1 ,pa4 ,pl4 #ba1 ,fig4 #h4 ,i have retained ,lewis' name as specific4 ,lewis1 wrongly1 ,i think1 ascribes his species to ,navicula trinodis ,wm4 ,sm41 which is not figured by ,smith1 but is illustrated by ,van ,heurck 7,syn4 ,pl4 #ad1 ,fig4 #ca;a71 and is named by ,cleve ,navicula contenta var4 biceps ,arnott4 #hb;,de ,toni includes ,lewis' name under ,rhoiconeis trinodis 7,wm4 ,sm47 ,grun4 ,rhoiconeis is achnanthiform1 with frustules arcuate1 and the species is named by ,cleve ,achnanthes trinodis 7,arnott74 ,caloneis schumanniana 7,grun47 ,cl41 to which as a variety ,cleve unites ,lewis' form1 appears to resemble it only in the lunate marks4 ,fig4 #i represents a single specimen found in the ,pavonia deposit and which ,i believe to be an abnormal form of ,c4 trinodis1 differing only in the degree of inflation and in the larger central area4 ,navicula trinodis var4 inflata ,schultze1 from ,staten ,island1 is the same form figured by ,lewis1 who states that certain specimens have produced apices4 ,,caloneis ,,permagna 7,,bail47 ,,cl4 ,valve lanceolate1 with produced apices2 median line nearly straight2 axial area lanceolate1 irregular or slightly unilateral1 about half the width of the valve2 stri1 #i in #aj 1 radiate and indistinctly punctate2 longitudinal lines double4 ,l4 #ajj-bjj 4 ,pinnularia permagna ,bail4 ,common in brackish water4 ,pl4 #ba1 ,fig4 #a4 ,,caloneis ,,permagna ,,var4 ,,lewisiana ,n4 ,,var4 ,valve lanceolate1 with undulating sides and sub-cuneate apices2 axial area less than one-third the width of the valve2 stri radiate1 #ab in #aj 1 indistinctly punctate2 longitudinal lines double1 closer together than in the type4 ,l4 #adj 4 ,lewis illustrates this variety in ,new and ,rare ,species1 ,pl4 #b1 ,fig4 #aa1 and states that it is probably ,navicula esox ,kuetzing4 ,this is an error1 as ,kuetzing's species is ,pinnularia esox ,ehr41 a form near ,p4 major4 ,rather common in the ,delaware ,river4 ,pl4 #ba1 ,fig4 #b4 ,,caloneis ,,formosa 7,,greg47 ,,cl4 ,valve lanceolate1 with sub-cuneate apices2 axial area one-fourth to one-fifth the width of the valve1 somewhat unilateral1 dilated in the middle2 stri1 #ab-ad in #aj radiate1 punctate2 longitudinal lines double1 distinct4 ,variable in size and outline4 ,abundant along the shores of the ,delaware ,river4 ,pl4 #ba1 ,fig4 #ah4 ,,caloneis ,,brevis ,,var4 ,,vexans 7,,grun47 ,,cl4 ,valve elliptical-lanceolate2 apices obtuse2 median fissures distant2 axial area narrow2 central area large1 orbicular2 longitudinal lines close together1 median4 ,shark ,river1 ,n4 ,j4 ,pl4 #ba1 ,fig4 #e4 ,,caloneis ,,wardii ,,cl4 ,valve linear1 ends cuneate2 axial area linear2 central area dilated to a stauros reaching the margin2 stri parallel1 radiate at the ends1 #ah in #aj 2 longitudinal lines marginal4 ,not uncommon in the ,delaware ,river4 ,pl4 #ba1 ,figs4 #f and #g4 #hc;,,caloneis ,,powellii 7,,lewis7 ,,cl4 ,valve linear1 with cuneate ends2 axial area linear2 central area large1 quadrate1 united to the wide longitudinal lines2 stri parallel1 smooth1 #h in #aj 4 ,long ,island 7,lewis72 ,smith's ,island1 ,delaware ,river4 ,pl4 #ba1 ,fig4 #aj4 ,,neidium ,,pfitzer 7#ahga7 7neidion1 dim4 of naus1 a boat7 ,valve linear or lanceolate2 median fissures turned in opposite directions1 terminal fissures appearing bifurcate 7872 stri transverse1 usually oblique1 finely punctate1 crossed by one or several longitudinal blank lines4 ,chromatophores1 two1 lying on the girdle side1 in cell division each forming a partially divided pair4 ,a large pyrenoid is said to be found in the middle of each chromatophore1 but ,mereschkowsky states that the pyrenoids are absent1 but that in ,n4 affine four eloplasts are always seen in the centre of the frustule4 ,a genus easily recognized by the peculiar terminal and median fissures and by the yellowish or brownish color of the valves when dry1 darker than in ,caloneis4 ,,neidium ,,affine 7,,ehr47 ,,pfitzer ,valve linear1 with protracted1 sub-rostrate or capitate ends4 ,navicula affinis ,ehr4 ,,neidium ,,affine ,,var4 ,,genuina ,,forma ,,maxima ,,cl4 ,stri1 #ad in #aj 1 punctate1 oblique in the middle1 convergent at the ends2 puncta1 #ae in #aj 4 ,l4 #bch 4 ,pensauken1 ,n4 ,j4 7artesian well74 ,pl4 #ba1 ,fig4 #aa4 ,var4 genuina forma minor ,cl4--,l4 #bf 2 stri1 #bd in #aj 4 ,brandywine ,creek4 ,pl4 #ba1 ,fig4 #ab4 ,,neidium ,,affine ,,var4 ,,amphirhyncus 7,,ehr47 ,,cl4 ,valve linear1 with protracted capitate ends2 stri transverse1 interrupted by several longitudinal lines4 ,willistown1 ,pa4 ,pl4 #ba1 ,fig4 #ac4 ,,neidium ,,amphigomphus 7,,ehr47 ,,pfitzer ,valve with parallel margins and cuneate ends2 stri transverse1 interrupted by several longitudinal lines2 central area widened transversely4 ,navicula amphigomphus ,ehr4 ,wissahickon4 ,pl4 #ba1 ,fig4 #ad4 ,,neidium ,,productum 7,,wm4 ,,sm47 ,,cl4 ,valve linear1 elongate1 with capitate apices2 stri slightly oblique2 longitudinal lines marginal2 axial area very narrow1 central area small4 ,navicula producta ,wm4 ,sm4 ,newtown ,square4 ,pl4 #ba1 ,fig4 #af4 #hd,,neidium ,,iridis 7,,ehr47 ,,cl4 ,valve linear or lanceolate-elliptical1 with sub-cuneate or rounded ends2 stri oblique1 about #ah in #aj 2 central area orbicular4 ,navicula iridis ,ehr4 ,navicula firma ,kuetz4 ,willistown1 ,pa42 ,middletown1 ,delaware ,co41 ,pa4 7,palmer74 ,pl4 #ba1 ,fig4 #ag4 ,the form here figured is probably the variety ampliata 7,ehr47 ,cl4 with less acute apices and more elliptical outline4 ,the species occurs in many variations1 the larger being found northward1 especially in the peat deposits of ,new ,england4 ,,neidium ,,hitchcockii 7,,ehr47 ,,cl4 ,valve linear1 with triundulate margin and cuneate ends2 stri transverse1 oblique4 ,navicula hitchcockii ,ehr4 ,pavonia1 ,n4 ,j4 7artesian well72 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #ba1 ,fig4 #ae4 ,,diploneis ,,ehr4 7#ahdj7 7diplos1 double7 ,valve elliptical or panduriform2 median line enclosed in strongly siliceous horns corresponding to the lyre-shaped areas of ,navicula lyra but never punctate2 central nodule1 quadrate2 valve costate1 or striate1 or both2 between the horns and the outer part are thinner spaces or sulci1 and1 in some species1 outside of the sulci are narrow spaces known as lunul4 ,chromatophores1 two1 upon the girdle or the valves4 ,pyrenoids have been found in one species only1 ,d4 interrupta4 ,,diploneis ,,elliptica 7,,kuetz47 ,,cl4 ,valve elliptical2 central nodule large2 sulci narrow1 curved1 close to the horns2 stri punctate1 in rows radiating more and more toward the ends4 ,variable in size and in the coarseness of puncta which are from #aj to #ac in #aj 7,cleve74 ,cleve describes ,d4 ovalis ,hilse as having the central nodule rounded1 but otherwise about the same as ,d4 elliptica1 and as equivalent to ,navicula ovalis ,a4 ,schmidt 7,atlas1 ,pl4 #g1 ,figs4 #cc to #cf74 ,very common in fresh water and occasional in brackish4 ,pl4 #bj1 ,fig4 #ad4 ,,diploneis ,,smithii 7,,br,b47 ,,cl4 ,valve elliptical2 central nodule not broad2 furrows evenly curved on the outer edge1 crossed by cost and double oblique rows of alveoli4 ,variable in size and in the curvature of the furrows4 ,cleve forms a new species1 ,d4 major1 of the large form figured by ,schmidt 7,atlas1 ,pl4 #g1 ,figs4 #ah1 #ai1 #ba and #bb71 stating that the structure is much coarser and the form is larger with broad furrows4 ,in the specimen here figured the size is median and the furrows are as in ,d4 major4 ,marine and brackish4 ,common4 ,pl4 #bj1 ,fig4 #ag4 #he;,,diploneis ,,crabro ,,var4 ,,pandura 7,,br,b47 ,,cl4 ,valve constricted1 segments tongue-shaped2 central nodule small2 horns narrow1 nearly parallel1 with a row of large puncta2 cost1 #d in #aj 1 convergent in the middle1 radiating at the ends1 alternating with a double row of puncta1 #aa in #aj 4 ,pavonia1 ,n4 ,j4 7artesian well74 ,pl4 #bj1 ,fig4 #d4 ,,diploneis ,,crabro ,,var4 ,,expleta 7,a4 ,s47 ,,cl4 ,valve slightly constricted1 segments tongue-shaped2 cost robust1 #e or #f in #aj 1 alternating with double rows of rather coarse puncta4 ,l4 #ef 4 ,port ,penn1 ,delaware ,river4 ,pl4 #bj1 ,fig4 #ae4 ,,diploneis ,,crabro ,,var4 ,,pandurella ,,cl48 ,valve constricted1 the lobes elliptical2 central nodule large1 with horns parallel in the middle1 convergent at the ends2 furrows wide1 with faint cost2 no lunula2 cost parallel in the middle1 radiate at the ends1 #i in #aj 1 alternating with very fine double rows of puncta 7not shown in the figure74 ,l4 #fe 4 ,blue clay4 ,pl4 #bj1 ,fig4 #ac4 ,,diploneis ,,crabro ,,var48 ,valve constricted1 segments elliptical2 cost1 #h in #aj 1 converging in the middle1 radiating at the ends2 horns narrow2 furrows wide1 costate2 lunul indistinct4 ,l4 #ge 4 ,resembles var4 pandurella except in the convergence of the cost and in the lunula4 ,squan ,river4 ,marine4 ,pl4 #bj1 ,fig4 #i4 ,,diploneis ,,fusca ,,var4 ,,delicata 7,a4 ,s47 ,,cl4 ,valve elliptical2 furrows broad1 crossed with rows of faint cost and alveoli2 cost1 #f or #g in #aj 2 alveoli1 #aj in #aj 1 in short1 irregular1 longitudinal rows4 ,l4 #hd 4 ,port ,penn1 ,delaware ,river4 ,pl4 #bj1 ,fig4 #aa4 ,,diploneis ,,gruendleri 7,a4 ,s47 ,,cl4 ,valve constricted1 segments tongue-shaped1 often unequal2 horns broad1 divergent in the middle2 furrows narrow2 cost transverse1 crossed by from #c to #g longitudinal cost1 interrupted in the middle at the border4 ,blue clay4 ,pl4 #bj1 ,figs4 #g and #h4 ,,diploneis ,,puella 7,,schum47 ,,cl4 ,valve elliptical1 sometimes orbicular2 furrows very narrow2 stri1 #bj in #aj 1 indistinct4 ,l4 #ae 4 ,diploneis elliptica var4 minutissima ,grun4 ,shark ,river1 ,n4 ,j4 ,brackish4 ,pl4 #bj1 ,fig4 #ab4 ,,diploneis ,,excentrica1 ,n4 ,,sp4 ,valve elliptical2 central nodule quadrate2 furrows of the same width throughout1 nearly parallel2 cost radiating toward the ends1 #aj in #aj 1 indistinct on the furrows1 alternating with alveoli1 #g in #aj 1 in irregular1 longitudinal lines4 ,one side of the valve is one and a half times the width of the other4 ,l4 #di 4 #hf;,i can find neither description nor figure of any species to which ,i can ascribe this form4 ,it approaches ,d4 elliptica4 ,the alveoli are quite distinct and distant from each other4 ,brackish water4 ,very abundant in a gathering from ,squan ,river1 ,n4 ,j4 ,pl4 #bj1 ,fig4 #aj4 ,,diploneis ,,oculata 7,,br,b47 ,,cl4 ,valve elliptical2 stri radiate at the ends1 about #bj in #aj 1 coarsely punctate4 ,l4 #bc 4 ,fresh water4 ,pl4 #bf1 ,fig4 #g4 ,the figure is drawn from ,brbisson's original material in ,h4 ,l4 ,smith's ,type ,slide ,no4 #bii4 ,navicula oculata ,brb4 ,reported from ,new ,jersey4 ,i have not seen this species in this locality4 ,navicula oculata1 referred to by ,kain as occurring in ,shark ,river1 is not this form4 ,,diploneis ,,gemmata 7,,grev47 ,,cl4 ,valve oblong-linear1 with cuneate ends and parallel or slightly concave sides2 central nodule large2 horns parallel2 furrows about one-third the width of the valve4 ,cost about #e in #aj 1 alternating with double rows of fine puncta2 short cost occur along the borders of the horns4 ,port ,penn1 ,delaware ,river4 ,pl4 #bj1 ,fig4 #af4 ,,diploneis ,,campylodiscus 7,,grun47 ,,cl4 ,valve suborbicular2 central nodule quadrate2 horns divergent2 cost1 #f in #aj 1 alternating with double rows of alveoli2 furrows broad1 costate near the horns4 ,differs from ,cleve's description in having #f1 instead of #d1 cost in #aj 4 ,pensauken1 ,n4 ,j4 7artesian well74 ,rare4 ,pl4 #bj1 ,fig4 #f4 ,,mastogloia ,,thwaites 7#ahef7 7mastos1 a breast1 and gloios1 gelatinous1 referring to the mamillate cushion in which the frustules are often immersed7 ,frustule rectangular4 ,valves similar1 naviculoid4 ,central and axial areas usually narrow or indistinct2 stri punctate1 parallel in the middle4 ,on each side1 between the valve and the zone1 is a septate plate4 ,,analysis ,,of ,,species ,stri interrupted by a hyaline furrow on each side of the median line kinsmanii ,stri not interrupted3 ,loculi1 five1 or less exigua more than five1 equal1 ending at distance from the ends smithii ending near the ends1 distinct lanceolata indistinct elegans very numerous apiculata unequal angulata #hg,karsten states that there are two chromatophores1 each of which extends from the middle of one valve to the end and down the middle of the other valve4 ,mereschkowsky says1 however1 that there are four plates or chromatophores1 sometimes on the valve1 sometimes on the zone1 according to the species1 and that two long pyrenoids unite the two opposite chromatophores4 ,,mastogloia ,,kinsmanii ,,lewis ,valve lanceolate-elliptical1 with sub-rostrate ends2 loculi more numerous than in ,m4 angulata but less than in ,m4 apiculata1 the middle ones larger4 ,median line with a sulcus on each side2 central area quadrate4 ,mastogloia braunii ,grun4 7,according to ,cleve74 ,atlantic ,city4 ,pl4 #ag1 ,fig4 #af4 ,,mastogloia ,,exigua ,,lewis ,valve elliptical- or linear-lanceolate2 loculi1 #b-e1 usually #c1 larger in the middle and rounded2 central space small2 stri1 #bj-bd in #aj 4 ,along the coast4 ,pl4 #ag1 ,fig4 #bd4 ,,mastogloia ,,smithii ,,thwaites ,valve lanceolate1 sub-rostrate2 loculi forming a wide band ending at a distance from the ends2 stri transverse1 with puncta forming longitudinal rows2 central area rounded or transversely elliptical4 ,along the coast4 ,pl4 #ag1 ,fig4 #ai4 ,,mastogloia ,,lanceolata ,,thwaites ,valve lanceolate1 with sub-rostrate apices2 loculi very numerous2 median and central areas indistinct2 stri1 #ai in #aj 1 punctate1 convergent at the ends4 ,along the coast4 ,pl4 #ag1 ,fig4 #ah4 ,,mastogloia ,,elegans ,,lewis ,valve lanceolate1 acute2 loculi indistinct or rudimentary1 extending to the ends2 central area apparently quadrate1 sometimes indistinct2 puncta distinct1 #ae in #aj 1 in transverse and longitudinal rows4 ,along the coast4 ,common4 ,pl4 #ag1 ,fig4 #bj4 ,,mastogloia ,,apiculata ,,wm4 ,,sm4 ,valve elliptical-lanceolate1 sometimes with slightly produced apices2 median line between two ribs2 central space very small2 loculi numerous2 puncta in slightly radiating rows and in longitudinal lines4 ,along the coast4 ,pl4 #ag1 ,figs4 #ba1 #bb1 #bc4 ,,mastogloia ,,angulata ,,lewis ,valve elliptical1 with produced apices2 loculi usually less than #ab1 unequal1 the larger in the middle2 stri1 #ab in #aj 1 puncta in decussating rows4 ,differs from apiculata in its more broadly elliptical shape1 the smaller number of its loculi and the angular character of its striation 7,lewis74 #hh;,considered by ,cleve as synonymous with ,m4 apiculata ,grun41 not ,wm4 ,smith1 and by ,de ,toni as synonymous with ,m4 apiculata ,wm4 ,sm4 ,in any case1 ,m4 angulata ,lewis is not the same as ,m4 apiculata ,wm4 ,sm41 the loculi of which are equal4 ,atlantic ,city4 ,h4 ,l4 ,smith ,t4 ,s4 ,no4 #baa4 ,pl4 #ag1 ,fig4 #ag4 ,,stauroneis ,,ehr4 7#ahdc7 7stauros1 a cross1 and neis 7naus71 a boat7 ,frustules free1 sometimes geminate2 valve as in ,navicula but with a stauros4 ,cell contents as in ,navicula4 ,mereschkowsky1 however1 says that the chromatophores always contain more pyrenoids than are found in ,navicula4 ,heinzerling gives the number as two to four in each chromatophore4 ,cleve includes under ,navicul ,microstigmatic all species of ,stauroneis1 ,pleurostauron1 ,schizostauron1 certain ,schizonem and ,navicul4 ,as a matter of convenience1 and because ,i have already included certain ,schizonem and ,scoliopleura under ,navicula1 and because of the small number of species in our locality1 ,i have arranged them under the three divisions of ,cleve as follows3 ,stauroneis4--,forms having a true stauros1 without diaphragms4 ,pleurostauron4--,forms like ,stauroneis but with diaphragms at the ends4 ,schizostauron4--,forms having a bifid stauros4 ,,stauroneis ,,phoenicenteron ,,ehr4 ,valve lanceolate1 obtuse2 stri radiate1 #ah in #aj 1 distinctly punctate4 ,l4 usually #abe but sometimes #bjj 4 ,common in fresh water4 ,pl4 #bg1 ,fig4 #a4 ,,stauroneis ,,anceps ,,ehr4 ,valve lanceolate1 with rostrate or capitate ends2 stauros in some cases does not reach the margin4 ,the varieties are very numerous4 ,var4 gracilis 7,ehr47 ,cl4--,valve lanceolate1 stri very fine2 margin of stauros striated4 ,l4 #ajj 4 ,cape ,may1 ,n4 ,j4 ,pl4 #bg1 ,fig4 #e4 ,var4 amphicephala 7,kuetz47 ,cl4--,valve capitate at the ends2 stri1 #bd in #aj 4 ,l4 #dg 4 ,fresh water4 ,pl4 #bg1 ,fig4 #g4 ,var4 8--,valve with produced ends2 stri1 #cj or more in #aj 4 ,l4 #ajd 4 ,willistown1 ,pa4 ,pl4 #bg1 ,fig4 #d4 ,var4 8--,valve with produced ends2 stri1 about #bh in #aj 1 punctate4 ,l4 #dg 4 ,newtown ,square4 ,pl4 #bg1 ,fig4 #h4 ,var4 8--,valve with produced ends2 stri1 #bb in #aj 1 showing a tendency to form longitudinal rows of puncta as in ,stauroneis stodderi ,greenleaf1 but the rows are not so evident4 ,l4 #fj 4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bg1 ,fig4 #i4 ,,stauroneis ,,frickei ,,var4 ,,angusta ,n4 ,,var4 ,valve lanceolate1 gradually tapering to the obtuse ends2 terminal fissures prominent1 forking at a distance of #g from the ends4 ,frustules frequently geminate4 ,l4 #agc 4 ,newtown ,square4 ,rare4 ,pl4 #bf1 ,fig4 #ah4 ,near ,stauroneis frickei ,a4 ,s4 7,atlas1 ,pl4 #bdb1 ,fig4 #af71 except that the stauros is narrow at the margin4 #hi,,stauroneis ,,salina ,,wm4 ,,sm4 ,valve lanceolate1 obtuse2 stauros narrow1 with short1 scattered stri at the margin1 #ah in #aj 1 punctate4 ,l4 #fe 4 ,along the coast4 ,common4 ,pl4 #bg1 ,fig4 #f4 ,,stauroneis ,,legumen ,,ehr4 ,valve elliptical-lanceolate1 inflated in the middle1 with produced sub-capitate or rostrate ends separated by diaphragms4 ,stauros wide1 striated at the margins2 axial area very narrow2 stri radiate1 about #bf 787 in #aj 1 punctate4 ,l4 #bh 4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #ci1 ,fig4 #ae4 ,in ,cleve's description and ,van ,heurck's figure1 the median inflation is not larger than the others4 ,in the present form the median inflation is wider4 ,,stauroneis ,,acuta ,,wm4 ,,sm4 ,valve rhombic-lanceolate1 obtuse2 a diaphragm at each end2 stauros widened outwards2 stri1 #ae or #af in #aj 1 punctate4 ,l4 #acj 4 ,blue clay4 ,pl4 #bg1 ,fig4 #b4 ,,stauroneis ,,americana ,a4 ,s4 ,valve elliptical-lanceolate1 obtuse2 stri1 #ad in #aj 4 ,l4 #aai 4 ,pavonia1 ,n4 ,j41 artesian well4 ,rare4 ,the only specimen found is asymmetrical with respect to the transverse axis4 ,on ,plate #dj1 ,fig4 #d1 is illustrated an abnormal form of ,stauroneis1 apparently near ,s4 acuta1 having an elongated central nodule and radiating1 curved and coarsely punctate stri4 ,blue clay4 ,,stauroneis ,,smithii ,,grun4 ,valve lanceolate1 inflated in the middle and at the ends1 which have diaphragms and are produced into rostrate apices2 stauros reaching the margin2 stri parallel1 about #be in #aj 7#bh to #cj1 ,cleve71 distinctly punctate4 ,not uncommon in meadow pools near ,newtown ,square4 ,pl4 #bg1 ,fig4 #aa4 ,,stauroneis ,,crucicula 7,,grun47 ,,cl4 ,valve lanceolate1 with obtuse1 produced ends2 stauros bifid2 stri1 #bd in #aj 1 oblique1 parallel to the branches of the stauros1 closer at the ends1 punctate4 ,l4 #cb 4 ,newtown ,square4 ,east ,park ,reservoir4 ,rare4 ,pl4 #bg1 ,fig4 #aj4 ,,navicula ,,bory 7#ahbf7 7dim4 of navis1 a boat7 ,valve linear to elliptical2 ends acute1 rounded1 rostrate1 capitate or truncate2 axial area usually distinct2 central area distinct1 rounded or rarely extended into a transverse fascia2 stri transverse or radiate1 punctate2 central area not dilated into a transverse stauros nor into horns4 #ij,the endochrome in the greater number of species consists of two chromatophores extending along the zone and sometimes partly over the valves4 ,sometimes1 however1 as in ,n4 hennedyi1 ,n4 lyra and ,n4 humerosa1 the bands are on the valves4 ,certain species have four bands1 others eight1 and in one the endochrome is granular4 7,mereschkowsky1 l4 c41 p4 #i et seq47 ,pyrenoids are usually absent4 ,on account of the diversity of the chromatophores1 ,mereschkowsky considers the genus not homogeneous4 ,the difficulty of arranging groups according to the cell contents1 however1 is so great that1 for the present1 the species must be described by the usual characteristics of the valves and divided as follows1 according to ,cleve1 to the extent of employing the classification of all ,naviculoid forms as applicable1 especially to the species of ,navicula4 ,van ,heurck's analysis includes ,pinnularia1 ,trachyneis1 ,diploneis1 ,caloneis1 ,neidium and ,anomoeoneis1 which are here separated1 while ,n4 lyra and ,n4 hennedyi are placed in different groups1 although they are closely related4 ,in other respects ,cleve's divisions correspond1 to some extent1 to those of ,van ,heurck4 ,the genus ,navicula at one time included the following3 ,dictyoneis1 ,pleurosigma1 ,gyrosigma1 ,caloneis1 ,neidium1 ,diploneis1 ,frustulia1 ,trachyneis1 ,anomoeoneis1 ,pinnularia and ,stauroneis1 and few forms with a raphe escaped4 ,for this reason the diagnosis of the present genus is somewhat limited4 ,pleurosigma and ,gyrosigma differ from ,navicula in their outline1 ,dictyoneis in the double stratification1 ,caloneis in the marginal lines1 ,neidium in the median and terminal fissures1 ,diploneis in the horns1 ,frustulia in the terminal nodules1 ,trachyneis in the stratification of the valve1 ,anomoeoneis in the longitudinal arrangement of the puncta1 ,pinnularia in the smooth cost and ,stauroneis in the stauros4 ,as the object of the present work is to aid the student of local forms in the identification of species by the briefest methods1 the further discussion of the reasons for classification will be left for his gratification in referring to the authorities on the subject4 ,,punctat ,,cleve ,valve elliptical to lanceolate2 central nodule not stauroid or continued into lyriform spaces2 stri distinctly or coarsely punctate1 in radiate rows4 ,,navicula ,,maculata 7,,bail47 ,,cl4 ,valve lanceolate-elliptical1 with produced or sub-rostrate ends2 axial area narrow1 wider near the ends and dilated to a rounded1 transverse central area2 stri radiate1 #f in #aj 1 puncta1 #g in #aj 1 in irregular1 longitudinal rows4 ,l4 #ij to #abj 7,cl474 ,stauroneis maculata ,bail4 ,navicula fischeri ,a4 ,s4 ,blue clay4 ,along the coast1 especially southward4 ,pl4 #bd1 ,fig4 #a4 ,,navicula ,,latissima ,,greg4 ,valve oblong-elliptical or elliptical-lanceolate1 with sub-cuneate ends2 axial area lanceolate1 widened in the middle to an orbicular space2 stri radiate1 #g in #aj 1 puncta1 #aa in #aj 1 the median stri alternating with short stri along the sides4 ,l4 #ej-aej 7,cl74 ,blue clay4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bd1 ,fig4 #c4 #ia,,navicula ,,latissima ,,var4 ,,elongata 7,,pant47 ,,cl4 ,valve elliptical-lanceolate1 with rounded ends2 stri and puncta closer than in the type form2 axial area narrow1 widened in the middle2 terminal fissures hook-shaped1 turned in different directions4 ,navicula humerosa var4 elongata ,pant4 ,fossil at ,buckshutem1 ,n4 ,j4 ,pl4 #bd1 ,fig4 #e4 ,,navicula ,,fuchsii ,,pant4 ,valve elliptical1 with slightly produced apices2 axial area wide1 lanceolate2 central area orbicular2 stri alternately longer and shorter in the middle1 #aj-ab in #aj 2 puncta on the border of the axial area larger1 elongated2 median fissures incrassate4 ,navicula humerosa var4 fuchsii 7,pant47 ,cl4 ,navicula 7latissima var487 fuchsii ,pant4 ,port ,penn1 ,delaware ,river4 ,pl4 #bd1 ,fig4 #f4 ,,navicula ,,humerosa ,,br,b4 ,valve lanceolate-elliptical or oblong-elliptical1 with sub-cuneate or sub-rostrate ends2 axial area narrow1 lanceolate2 central area rounded1 somewhat transverse2 terminal fissures hook-shaped1 in the same direction2 central pores incrassate2 stri1 #aa in #aj 1 the middle alternately longer and shorter1 closer at the ends4 ,l4 #fj-hf 4 ,variable in size1 outline and fineness of striation4 ,n4 monilifera ,cleve 7,n4 granulata ,brb47 differs in having coarser stri4 ,blue clay4 ,along the coast4 ,pl4 #be1 ,fig4 #e4 ,,navicula ,,pusilla ,,wm4 ,,sm4 ,valve ovate-elliptical1 with rostrate or sub-rostrate ends2 axial area narrow2 central area elliptical2 stri radiate1 #aj-ab in #aj in the middle where they are longer and shorter alternately1 closer at the ends2 median fissures somewhat incrassate1 terminal in the same direction4 ,l4 #dg 4 ,smith's ,island1 ,delaware ,river4 ,pl4 #be1 ,figs4 #d1 #f8 ,cleve gives the stri as #ac-ah in the typical form1 and #aa-ac in varieties4 ,in the form here figured the striation is as stated by ,de ,toni1 but is about #ai at the ends4 ,fig4 #f appears to be a small form of ,n4 pusilla1 near lanceolata ,grun41 at least according to the figure in ,arctic ,diatoms1 but not ,gregory's figure4 ,it occurs rarely in fresh water at ,newtown ,square4 ,it may be a small form of ,n4 punctulata and1 if so1 is probably accidental1 as the material is entirely fresh-water4 ,,navicula ,,pusilla ,,var4 ,,subcapitata ,n4 ,,var4 ,valve elliptical with rostrate-capitate and truncate ends2 stri about #ab in #aj in the middle where they are unequal2 axial area narrow1 slightly widened in the middle2 central pores incrassate1 terminal fissures in the same direction4 ,differs from type in outline and centre4 ,pavonia1 ,n4 ,j41 artesian well4 ,rare4 ,pl4 #be1 ,fig4 #h4 #ib,,navicula ,,delawarensis ,,grun4 ,valve elliptical-lanceolate1 with sub-rostrate ends2 axial area narrow1 lanceolate1 widened in the middle2 stri about #aj in #aj 2 in the middle1 much closer at the ends2 puncta in the middle1 #i in #aj 1 closer and much smaller at the ends4 ,l4 #eh-ie 4 ,cleve 7,le ,diatomiste1 ,vol4 #b1 p4 #ad7 states that this form is very near ,n4 pusilla but is much larger4 ,specimens from ,smith's ,island measure #eh-fe 1 from ,wildwood1 #ie in length4 ,pl4 #be1 ,fig4 #c4 ,,navicula ,,punctulata ,,wm4 ,,sm4 ,valve elliptical-lanceolate1 with sub-rostrate ends2 axial area narrow1 central area rounded2 stri1 #aa in #aj 1 closer at the ends1 a few shorter in the middle2 puncta1 #aj in #aj 4 ,l4 #ed 4 ,navicula marina ,ralfs4 ,port ,penn1 ,delaware ,river 7brackish water74 ,pl4 #be1 ,fig4 #i4 ,although this species is described as marine in the ,synopsis of ,prof4 ,smith1 ,i have never found it in purely marine localities 7,donkin74 ,,navicula ,,punctata ,,var4 ,,asymmetrica ,,lagerstedt ,valve lanceolate1 with rostrate ends2 axial area narrow1 central area transverse1 irregular2 stri radiate1 punctate1 #ab in #aj 4 ,l4 #cf 4 ,navicula amphibola ,cleve4 ,blue clay4 ,pl4 #bg1 ,fig4 #ae4 ,,navicula ,,brasiliensis ,,var4 ,,bicuneata ,,cl41 ,,forma ,,constricta ,valve oblong-elliptical1 slightly constricted1 with cuneate-rostrate ends2 axial area narrow2 central area dilated transversely and unilaterally2 stri1 #i in #aj 2 puncta closer at the border and in irregular longitudinal rows in the middle2 terminal fissures small1 hook-shaped1 turned in the same direction4 ,l4 #ic 4 ,corresponds closely to ,cleve's variety except in the constriction4 ,blue clay4 ,pl4 #be1 ,fig4 #b4 ,,navicula ,,lacustris ,,greg4 ,valve lanceolate1 sub-acute2 axial area narrow2 central area orbicular2 stri radiate1 #ad in #aj 1 punctate1 the median puncta sometimes more distant than the others4 ,blue clay4 ,rare4 ,pl4 #bg1 ,fig4 #ab4 ,,lyrat ,,cl4 ,valve elliptical or elliptical-lanceolate2 stri punctate1 transverse2 axial area narrow or indistinct2 central area expanded on each side into lyre-shaped or horn-like blank spaces4 ,,navicula ,,pr,,texta ,,ehr4 ,valve elliptical2 lateral areas not regular1 with scattered puncta2 stri radiate1 #e or #f in #aj 2 puncta1 #g or #h in #aj 2 along the axial area1 a single or double row of puncta2 at #icthe middle of the border1 on each side1 two stri approach each other closely with a short stria between them2 terminal fissures small1 in the same direction4 ,l4 #abj 4 ,port ,penn1 ,delaware ,river4 ,pl4 #bd1 ,fig4 #b4 ,while variable in size and striation1 approaching ,n4 hennedyi1 this species1 as here figured1 is found in the ,miocene and later deposits and is extant in most parts of the world4 ,,navicula ,,irrorata ,,grev4 ,valve oblong-elliptical1 with cuneate-rostrate ends2 stri1 #g or #h in #aj 1 puncta1 #g in #aj 2 axial area bordered by puncta in unequal1 transverse rows4 ,l4 #hd 4 ,blue clay4 ,rare4 ,pl4 #bd1 ,fig4 #d4 ,,navicula ,,hennedyi ,,wm4 ,,sm4 ,valve elliptical2 areas semilanceolate2 stri about #aa in #aj 1 sometimes longer and shorter on the margin2 short rows of transverse stri along the axial area4 ,blue clay4 ,pl4 #be1 ,fig4 #ab4 ,var4 circumsecta ,grun4--,as in the type but with the lateral areas faintly striate or punctate4 ,var4 manca ,a4 ,s4--,valve lanceolate-elliptical1 the lateral areas narrow and convergent toward the ends2 short rows of transverse stri along the axial area2 stri1 #i in #aj 2 central pores incrassate4 ,blue clay4 ,pl4 #be1 ,fig4 #aa4 ,,navicula ,,lyra ,,ehr4 ,valve elliptical1 with rounded1 sub-rostrate or sub-cuneate ends2 lateral areas narrow2 stri1 #f to #ad in #aj 7,cl471 punctate4 ,l4 #ej-ahj 4 ,var4 ehrenbergii ,cl4--,lateral areas constricted in the middle1 divergent at the ends4 ,cleve refers to ,schmidt1 ,atlas1 ,pl4 #b1 ,fig4 #be1 which is not divergent at the ends4 ,along the coast4 ,pl4 #be1 ,fig4 #aj4 ,a narrower form occurs which has the areas divergent4 ,var4 8--,valve elliptical1 lateral areas narrow1 convergent at the ends with short rows of punctate stri2 marginal stri1 #aj in #aj 1 punctate4 ,l4 #fj 4 ,squan ,river1 ,n4 ,j4 ,pl4 #bj1 ,fig4 #e4 ,var4 dilatata ,a4 ,s4--,valve elliptical1 rostrate2 lateral areas convergent in the middle and nearly parallel or convergent at the ends4 ,blue clay4 ,pl4 #be1 ,fig4 #ac4 ,n4 lyra is exceedingly variable in outline1 fineness of striation and in the lateral areas4 ,intermediate forms occur approaching ,n4 hennedyi and ,n4 spectabilis4 ,in ,n4 hennedyi the lateral areas are broad1 semilanceolate1 not narrowed in the middle4 ,in ,n4 spectabilis the lateral areas are broad and narrowed in the middle4 ,in ,n4 lyra the lateral areas are narrow and either constricted or not in the middle4 ,in many forms in #idthese three species the lateral areas are more or less striated or punctate4 ,cleve does not consider this a distinction of any importance1 although certain varieties are founded upon it4 ,all three species are very common in the blue clay and along the coast1 but their varieties are too numerous to describe or figure4 ,,navicula ,,spectabilis ,,var4 ,,emarginata ,,cl4 ,valve elliptical2 lateral areas broad1 narrowed in the middle1 delicately striated2 marginal stri1 #aj in #aj 4 ,l4 #gj 4 ,blue clay4 ,pl4 #be1 ,fig4 #g4 ,,navicula ,,pygm,a ,,kuetz4 ,valve elliptical1 appearing hyaline2 axial and central areas faint2 lateral areas convergent in the middle2 stri indistinct1 about #be in #aj 4 ,l4 #bc 4 ,brandywine ,creek 7,palmer74 ,pl4 #bg1 ,fig4 #bc4 ,,decussat ,,cl4 ,valve elliptical or lanceolate2 axial area narrow2 central area small2 stri punctate1 in transverse and oblique1 curved rows4 ,,navicula ,,placenta ,,ehr4 ,valve elliptical1 with short1 rostrate-capitate ends2 axial area narrow2 central area elliptical2 stri in two directions1 the transverse about #bb 7to #bg1 ,cl47 in #aj 1 the oblique stri crossing in both directions in curved lines appearing coarser than the transverse 7,lewis74 ,a very peculiar species which1 as ,cleve remarks1 seems not to be allied to any other4 ,l4 about #ce 1 quite constant in size4 ,it is reported from ,finland1 ,scotland1 ,hungary and ,new ,zealand4 ,dr4 ,lewis found it in the ,delaware ,river4 ,it is occasional in the ,schuylkill ,river and the blue clay1 and very abundant on ,marchantia and mosses on the wet rocks of the upper ,wissahickon 7,f4 ,j4 ,keeley74 ,pl4 #bg1 ,fig4 #ag4 ,,lineolat ,,cl4 ,valve more or less lanceolate2 axial area narrow or indistinct2 stri radiate or parallel1 lineate1 that is1 with the puncta closer than the stri4 ,,navicula ,,radiosa ,,kuetz4 ,valve lanceolate with sub-rostrate apices2 axial area indistinct2 central area small2 stri radiate in the middle1 from #f to #h in #aj 1 and convergent at the ends1 about #ab in #aj 4 ,l4 #dg 4 ,very common in fresh water4 ,pl4 #bf1 ,fig4 #ag2 ,pl4 #dj1 ,fig4 #i4 ,,navicula ,,peregrina ,,ehr4 ,valve lanceolate1 obtuse2 axial area narrow2 central area large1 rounded or slightly irregular2 stri coarse in the middle1 #e in #aj 1 radiate2 convergent at the ends1 #g or #h in #aj 4 ,abundant in brackish water4 ,delaware ,river4 ,pl4 #bf1 ,fig4 #bj4 #ie,,navicula ,,cyprinus 7,,wm4 ,,sm47 ,valve lanceolate1 slightly gibbous in the middle1 sub-cuneate at the ends2 axial area narrow2 central area small2 stri radiate in the middle1 #aj in #aj 1 with shorter1 transverse stri intermediate2 transverse at the extreme ends4 ,l4 #hb 4 ,navicula digito-radiata var4 cyprinus 7,ehr4 87 ,wm4 ,sm4 ,whether the form here figured is ,ehrenberg's or not1 it is the species known as ,pinnularia cyprinus ,ehr4 of ,wm4 ,smith4 ,common in ,shark ,river1 ,n4 ,j4 ,pl4 #bf1 ,fig4 #ba4 ,,navicula ,,reinhardtii ,,grun4 ,valve elliptical or elliptical-lanceolate1 with broad1 rounded ends2 axial area narrow1 widened at the ends to the width of the valve2 central area widened transversely to an irregular1 quadrate space2 stri coarse1 #h in #aj 1 distinctly lineate1 alternately longer and shorter in the middle1 radiate1 nearly transverse at the ends4 ,l4 #ei 4 ,blue clay4 ,rare4 ,pl4 #bf1 ,fig4 #bb4 ,,navicula ,,lanceolata ,,var4 ,,arenaria 7,,donk47 ,,cl4 ,valve lanceolate2 axial area very narrow or indistinct2 central area small1 rounded2 stri radiate1 #aa in #aj in the middle1 closer at the ends4 ,l4 #dg-ed 4 ,navicula arenaria ,donk4 ,shark ,river1 ,n4 ,j4 ,pl4 #bf1 ,fig4 #bc4 ,,navicula ,,salinarum ,,grun4 ,valve elliptical-lanceolate with produced sub-capitate or rostrate ends2 stri radiate in the middle1 longer and shorter2 transverse at the ends1 lineate4 ,l4 #cb 4 ,atlantic ,city1 ,n4 ,j4 ,pl4 #bf1 ,fig4 #bd4 ,,navicula ,,viridula ,,var4 ,,rostellata ,,kuetz4 ,valve lanceolate with rostrate ends2 axial area very narrow1 central area orbicular2 stri radiate in the middle1 about #ab in #aj 1 convergent at the ends and closer4 ,l4 #dc 4 ,common in fresh water4 ,pl4 #bf1 ,fig4 #af4 ,,navicula ,,gracilis ,,var4 ,,schizonemoides 7,,ehr47 ,v4 ,h4 ,valve lanceolate1 obtuse2 axial area widened in the middle2 stri radiate in the middle1 about #ab in #aj 1 transverse or slightly convergent at the ends4 ,l4 #de-fj 4 ,occurs in gelatinous tubes2 usually found free4 ,colletonema neglectum ,thwaites4 ,fresh water4 ,pl4 #bf1 ,fig4 #ai4 ,,navicula ,,ramosissima 7,,ag47 ,,cl4 ,valve lanceolate1 sub-acute2 axial area very narrow2 central area scarcely widened2 stri1 #ab in #aj 1 parallel throughout4 ,l4 #de 4 ,micromega ramosissimum ,ag4 ,schizonema smithii ,kuetz4 7not ,ag474 ,east ,river1 ,n4 ,y4 ,pl4 #bf1 ,fig4 #ad4 #if,,navicula ,,anglica ,,ralfs ,valve elliptical1 with sub-capitate or rostrate ends2 axial area narrow1 central area small2 stri radiate1 #ab-ac in #aj 1 distinctly punctate4 ,l4 #bf 4 ,fresh water4 ,pl4 #bf1 ,fig4 #bf4 ,,navicula ,,gastrum ,,ehr4 ,valve elliptical1 with rostrate ends2 axial area narrow1 central area transverse or irregular2 stri radiate1 #i in #aj in the middle4 ,l4 #bf 4 ,the form here figured approaches ,n4 anglica4 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #bf1 ,fig4 #be4 ,,navicula ,,dicephala ,,wm4 ,,sm4 ,valve linear1 with rostrate or rostrate-capitate ends2 axial area narrow1 central area rectangular1 transverse2 stri radiate1 #ab in #aj 4 ,l4 #cb 4 ,fresh water4 ,pl4 #bg1 ,fig4 #af4 ,,navicula ,,humilis ,,donk4 ,valve elliptical1 with broad1 rostrate ends2 axial area narrow2 central area small2 stri radiate and distant in the middle1 convergent at the ends1 coarse1 appearing costate1 averaging #i in #aj 4 ,l4 #ai 4 ,as ,donkin states1 the stri are very conspicuous4 ,navicula hungarica var4 capitata 7,ehr47 ,cl4 ,navicula globiceps ,lagerstedt1 according to ,cleve4 ,willistown1 ,pa4 ,pl4 #bg1 ,fig4 #bd4 ,,navicula ,,pinnata ,,pant4 8 ,valve lanceolate1 obtuse2 axial area narrow1 widened in the middle2 stri coarse1 #g in #aj in the middle1 radiate1 #aj in #aj at the ends and transverse1 indistinctly lineate4 ,l4 #dj 4 ,near ,navicula ardua ,mann 7,diat4 ,albatross ,voy41 ,cont4 ,u4 ,s4 ,nat4 ,herbarium ,vol4 #aj1 ,part #e1 p4 #ccf1 ,pl4 #ec1 ,fig4 #b7 which1 however1 is said to have strictly unbeaded cost4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bg1 ,fig4 #bj4 ,,navicula ,,pennata ,a4 ,s4 ,valve lanceolate1 acute2 axial area narrow2 central area quadrate1 transverse2 stri radiate1 coarse1 #e in #aj 1 lineate4 ,l4 #fh-ie 7,cleve74 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bg1 ,fig4 #bb4 ,,navicula ,,inflexa ,,greg4 ,valve slightly elliptical-lanceolate1 sub-acute1 smooth at the ends2 axial area narrow1 widened in the middle2 stri radiate1 #aa in #aj 1 lineate4 ,frustule in zone view constricted in the middle4 ,l4 #bh-de 4 ,common along the coast4 ,pl4 #bg1 ,figs4 #ah and #ai4 #ig,,navicula ,,oblonga ,,kuetz4 ,valve linear-lanceolate1 with broad1 rounded ends2 margin sometimes undulate2 axial area narrow2 central area large1 orbicular2 stri in the middle distant1 radiate1 convergent at the ends and curved or sharply bent1 #g in #aj 1 lineate4 ,l4 #gj-bjj 7,cleve74 ,blue clay4 ,occasional in fresh water4 ,pl4 #bg1 ,fig4 #ba4 ,,navicula ,,hasta ,,pant4 ,valve lanceolate1 gently tapering to the obtuse1 produced ends2 axial area lanceolate1 widened to an orbicular space in the middle2 stri radiate1 the median coarse and quite distant1 #e in #aj 1 becoming closer at the ends where they are #ab in #aj 1 lineate4 ,the distance between the median stri gives the appearance of a stauros4 ,occasional in the blue clay4 ,pl4 #bg1 ,fig4 #ac4 ,,navicula ,,hasta ,,var4 ,,punctata ,n4 ,,var4 ,valve as in type but with stri in the middle distinctly punctate and reaching the median line4 ,greenwich ,point1 ,philadelphia4 ,pl4 #bg1 ,fig4 #ad4 ,,navicula ,,rhyncocephala ,,kuetz4 ,valve lanceolate1 with produced ends2 axial area indistinct2 central area small1 rounded2 stri radiate in the middle1 convergent at the ends1 #aj-aa in #aj 1 punctate4 ,l4 #db 4 ,fresh water4 ,common4 ,pl4 #ca1 ,fig4 #h4 ,,navicula ,,cryptocephala ,,kuetz4 ,valve lanceolate1 with rostrate ends2 axial area indistinct2 central area small2 stri1 #af in #aj 1 lineate1 radiate in the middle1 convergent at the ends4 ,l4 #bh 4 ,common in fresh water4 ,intermediate forms occur between ,n4 rhyncocephala and ,n4 cryptocephala4 ,pl4 #ca1 ,fig4 #i4 ,,navicula ,,longa 7,,greg47 ,,ralfs ,valve slender1 rhombic1 elongated1 with acute ends2 axial area indistinct2 central area small2 stri1 #f or #g in #aj 1 radiate in the middle1 elsewhere transverse2 central pores closely approximate4 ,l4 #abj 4 ,new ,rochelle1 ,n4 ,y4 ,pl4 #ca1 ,fig4 #aj4 ,cleve refers this form to ,n4 directa var4 remota ,grun4 ,some specimens are found in this locality showing the generally twisted median line mentioned by ,gregory4 ,,mesolei ,,cl4 ,valve linear or elliptical2 axial area narrow2 central area quadrate2 stri radiate1 finely punctate4 ,,navicula ,,mutica ,,kuetz4 ,valve ovate1 elliptical or lanceolate2 axial area narrow2 central area dilated into a stauros not reaching the margin2 stri about #bj in #aj 1 more distant in the middle1 radiate1 punctate4 ,a punctum occurs on one side of the central nodule4 #ih,reported from ,new ,jersey in fresh water4 ,i have not found it4 ,the figure is from a specimen from another locality4 ,pl4 #bf1 ,fig4 #f4 ,,navicula ,,minima ,,grun4 ,valve broadly elliptical1 #ac-ae in length2 axial area narrow2 central area small but with a quadrate pseudo-stauros which is striated2 stri1 about #bh in #aj 1 radiate4 ,agrees closely with ,n4 saugeri var4 ,grun4 in ,v4 ,h4 ,synopsis1 ,pl4 #ad1 ,fig4 #af1 said to be intermediate between ,n4 minima and ,n4 atomoides ,grun4 ,n4 minima var4 atomoides ,grun4 is smaller4 ,common in water-troughs4 ,pl4 #bf1 ,fig4 #ac4 ,,navicula ,,pupula ,,var4 ,,bacillarioides ,,grun4 ,valve linear1 with rounded ends2 axial area linear1 expanding on both sides near the ends of the valve1 forming a transverse lunate space2 central area small1 apparently expanded into a stauros1 which1 however1 is striated2 stri1 #ah in #aj 1 at the middle1 closer at the ends1 punctate4 ,l4 #ed 4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bf1 ,fig4 #i4 ,,bacillares ,,cl4 ,valve linear or linear-elliptical1 with broad ends2 axial area narrow1 the median line enclosed in siliceous ribs2 stri finely punctate1 more distant in the middle4 ,,navicula ,,bacillum ,,ehr4 ,valve linear1 with rounded ends2 axial area enclosed in siliceous ribs and slightly expanded on each side at the ends2 terminal nodules incrassate2 central area small1 elliptical2 stri1 #ae in #aj in the middle1 transverse1 distinctly punctate1 closer at the ends ,l4 #dg 4 ,fresh water4 ,pl4 #bf1 ,fig4 #aj4 ,cleve describes the form as having slightly radiate stri in the middle4 ,there is considerable difference in the descriptions of ,cleve1 ,donkin1 ,grunow and ,van ,heurck1 as also in all of the figures4 ,,navicula ,,americana ,,ehr4 ,valve oblong-linear1 with rounded ends1 sometimes slightly constricted2 axial area about one-half the width of the valve1 dilated in the middle2 stri parallel in the middle1 radiate at the ends1 #ae-af in #aj 4 ,a punctum is usually found in the central nodule4 ,l4 #ee-aed 4 ,blue clay4 ,occasional in fresh water4 ,pl4 #bf1 ,fig4 #h4 ,,decipientes ,,cl4 ,valve lanceolate1 with obtuse ends2 axial area narrow2 central area orbicular2 stri radiate in the middle and more distant4 ,,navicula ,,semen ,,ehr4 ,valve elliptic-lanceolate1 with sub-rostrate1 truncate apices2 axial area narrow1 #iisinuous2 central area orbicular2 terminal fissures small1 hook-shaped2 stri robust1 #g or #h in the middle1 closer at the ends1 indistinctly punctate or lineolate4 ,blue clay4 ,not common4 ,pl4 #bf1 ,fig4 #aa4 ,cleve states that this form belongs to the post-glacial deposits and is found living only in the ,hartz ,mountains4 ,,navicula ,,integra ,,wm4 ,,sm4 ,valve lanceolate with triundulate margins and rostrate-apiculate ends2 stri radiate1 more distant in the middle1 #bj-bc in 1 punctate2 axial area very narrow1 central area rounded or elliptical4 ,l4 #cc-dc 4 ,pavonia1 ,n4 ,j41 artesian well4 ,common in ,chester ,river1 ,md4 ,pl4 #bf1 ,fig4 #e4 ,,microstigmatic ,,cl4 ,valve lanceolate2 axial area narrow2 central area small1 rounded2 stri finely punctate1 nearly parallel4 7,includes here only the division ,libellus47 ,,navicula ,,tumida 7,,br,b47 ,,cl4 ,valve lanceolate1 with rounded ends2 axial area narrow1 central area elliptical2 raphe slightly sigmoid2 stri1 #ac in #aj 1 finely punctate1 a few shorter in the middle4 ,scoliopleura tumida 7,brb47 ,v4 ,h4 ,cape ,may1 ,n4 ,j4 ,pl4 #be1 ,fig4 #a4 ,,navicula ,,grevillei 7,,ag47 ,,cl4 ,frustules in gelatinous tubes1 rectangular2 zone with numerous longitudinal divisions4 ,valve elliptical-lanceolate1 obtuse2 axial area narrow1 central area small2 stri lineate1 about #ah in #aj in the middle where they are slightly radiate and more evident1 closer near the ends and transverse2 median line with terminal pores distant from the ends4 ,l4 #fj 4 ,schizonema grevillei ,ag4 ,east ,river1 ,n4 ,y4 ,pl4 #ca1 ,figs4 #c and #d4 ,,navicula ,,libellus ,,greg4 ,valve rhombic-elliptical1 obtuse at the ends2 axial area narrow1 central rounded1 small2 stri punctate1 slightly radiate1 about #ai in #aj 2 terminal fissures close to the ends1 indistinct4 ,l4 #fj 4 ,cleve describes this form as having acute ends1 while ,gregory states that it is more obtuse and broader than ,n4 rhombica4 ,gregory's ,figure #aja apparently shows the ends acute1 but he says that the valve view is rhombic or elliptic-lanceolate1 broad1 with obtuse ends 7,diat4 of the ,clyde1 p4 #eg1 ,pl4 #f74 ,hackensack ,swamp1 ,n4 ,j4 ,pl4 #ca1 ,fig4 #e4 ,,orthostich ,,cl4 ,valve lanceolate or elongated2 axial area narrow2 central area sometimes apparently dilated into a stauros2 stri punctate1 the puncta in transverse and longitudinal rows4 #ajj,,navicula ,,cuspidata ,,kuetz4 ,valve rhombic-lanceolate1 with acute ends2 axial area linear1 narrow1 not widened in the middle2 stri transverse1 #ad-ai in #aj 7,cl474 ,l4 #gj-aej 4 ,blue clay4 ,not uncommon in fresh water4 ,pl4 #bf1 ,figs4 #a and #b4 ,fig4 #b represents an inner valve or stratum1 with strong cost variable in size1 formerly known as ,surirella craticula ,ehr4 ,n4 cuspidata var4 ambigua 7,ehr47 ,cl4--,valve elliptical-lanceolate1 with rostrate ends1 smaller than the type and with finer stri4 ,crum ,creek4 ,pl4 #bf1 ,fig4 #c4 ,,navicula ,,spicula 7,,hickie7 ,,cl4 ,valve narrow1 lanceolate with acute ends2 axial area narrow1 central area dilated into a stauros reaching the margin2 transverse stri1 #be-bi in #aj 1 longitudinal closer4 ,l4 #ej-acj 7,cl474 ,sometimes confused with ,n4 crucigera4 ,stauroneis spicula ,hickie4 ,newark1 ,n4 ,j4 ,pl4 #bf1 ,fig4 #d4 ,,navicula ,,crucigera 7,,wm4 ,,sm47 ,,cl4 ,valve lanceolate1 narrow1 with acute apices2 central nodule a stauros reaching the margin but crossed by two or three coarser stri2 transverse stri1 #ab in #aj 1 punctate1 the puncta about #be in #aj 4 ,l4 #hj-ajj 7,cl474 ,frustules in gelatinous tubes or free4 ,schizonema cruciger ,wm4 ,sm4 ,pl4 #bf1 ,fig4 #ae4 ,reported as occurring in ,new ,york ,bay1 but ,i have not seen it4 ,the figure is from a specimen from another locality4 ,,minuscul ,,cl4 ,valve lanceolate or elliptical1 chiefly distinguished by the small size2 axial area indistinct2 central area small2 stri radiate1 very finely punctate4 ,,navicula ,,atomus ,n,,geli ,valve elliptical1 #f-h in length2 stri radiate1 #bf-cj 1 closer near the ends2 axial area linear1 scarcely widened in the middle4 ,water-troughs and ditches4 ,probably common1 but frequently not noticed because of its minuteness4 ,a mounting medium of the highest refractive index1 such as realgar1 is required to resolve the stri4 ,in the figure the stri are drawn a little coarser than they appear in most specimens4 ,pl4 #bf1 ,fig4 #ab4 ,l,,vistriat ,,cl4 ,valve lanceolate1 axial area distinct2 central area orbicular2 stri coarse1 indistinctly punctate1 approaching the cost of ,pinnularia4 #aja,,navicula ,,yarrensis ,,grun4 ,valve elliptical-lanceolate1 with rounded ends2 axial area lanceolate1 widened in the middle2 stri1 #e in #aj 4 ,l4 #ig 4 ,cape ,may1 ,n4 ,j4 ,common4 ,pl4 #be1 ,fig4 #ad4 ,fig4 #ae1 a smaller form1 #fe in length2 stri1 #f in #aj 4 ,fig4 #af1 #ed in length2 stri1 #h in #aj 7near var4 valida ,pant474 ,,navicula ,,elegans ,,wm4 ,,sm4 ,valve elliptical-lanceolate1 with produced ends2 axial area very narrow1 central area large1 orbicular2 stri strongly divergent in the middle1 slightly1 if at all1 convergent at the ends1 curved toward the margin1 indistinctly lineate1 #i in #aj 4 ,l4 #ie 4 ,blue clay4 ,not rare4 ,pl4 #ca1 ,fig4 #a4 ,navicula elegans var4 cuspidata ,cl4--,valve as in type form but smaller and with rostrate apices2 stri1 #aj in #aj 4 ,l4 #hb 4 ,belmar1 ,n4 ,j4 ,pl4 #ca1 ,fig4 #b4 ,cleve remarks that the type form is acute and the stri #i1 while the var4 cuspidata has #ab stri in #aj 4 ,in ,fig4 #a1 ,pl4 #ca1 is represented a valve having #i stri in #aj 1 but not acute1 while ,fig4 #b1 with but slight variation in stri1 is more cuspidate4 ,it is probable there are intermediate variations4 ,,navicula ,,palpebralis ,,br,b4 ,valve elliptical-lanceolate1 with acute apiculate ends2 axial area broad1 lanceolate2 stri radiate1 lineate1 about #aa in #aj 4 ,l4 #fj 4 ,along the coast4 ,pl4 #ca1 ,figs4 #f and #g4 ,on ,plate #dj1 ,fig4 #e1 is represented an abnormal form of ,navicula in which the central pores are in a line transverse to the longitudinal axis and each raphe is curved in a line which almost returns to the centre4 ,the puncta are in curved lines radiating from the rounded hyaline centre4 ,pavonia1 ,n4 ,j41 artesian well4 ,weissflog has described valves of ,navicula somewhat similar in punctation4 ,,pinnularia ,,ehr4 7#ahdc7 7pinnula1 a small feather7 ,valve linear or nearly so1 with rounded ends2 axial area broad2 central and terminal areas large2 cost smooth1 transverse or radiating1 usually convergent at the ends4 ,the cost are channels on the inside of the valve1 closed1 except in the middle where elliptical foramina1 opening into the interior of the valve1 give rise through their terminal margins to the two longitudinal lines on each side of the valve4 ,the raphe begins as a groove in the side of the conical central nodule and continues as a cleft at right angles to the plane of the surface of the valve1 in which case the raphe forms a single line2 if the raphe is inclined to the valve surface1 then two lines appear in projection1 the upper and lower edges of the cleft4 ,in some forms the surface of the edge of the raphe on one side is folded or grooved for a considerable distance1 and the opposite edge is elevated into a ridge or #ajbtongue fitting into the groove4 ,in such cases it is possible1 in projection1 to see the upper or outer edges of the raphe1 the lower edges and the edges of the tongue and groove1 thus showing four lines2 sometimes1 when the tongue and groove do not meet1 six lines4 ,the so-called inner channel is the part of the raphe on the inside of the tongue1 and the so-called exterior channel is the part of the raphe on the outside of the tongue4 ,if1 in addition to this formation of the raphe1 the plane of cleavage changes toward the terminal nodules1 the lines will cross each other and1 when two are superimposed1 disappear altogether4 ,for the careful examination of the raphe it is necessary to employ large forms1 and it is advisable to use nitrate of silver which remains in the raphe1 and1 as in slides mounted by ,mr4 ,f4 ,j4 ,keeley1 shows in a beautiful manner the entire outline of raphe and fissures4 ,the terminal fissures owe their separation to the different directions taken by the two edges of the raphe on each side1 one edge bending in a wide curve toward the end of the valve1 showing two lines1 the upper and lower edges of one side of the raphe when inclined to the plane of the surface1 and the other edge of the raphe turning suddenly in an opposite direction and ending abruptly in a curve1 giving rise to the appearance1 by diffraction1 of a punctum4 ,pl4 #dj1 ,figs4 #ac1 #ad and #ae4 ,endochrome consists of two chromatophores lying on the zones4 ,pinnularia is usually divided into the ,majores1 or larger1 and the ,minores1 or smaller forms1 the latter being further divided according to their stri4 ,the following classification is chiefly that of ,cleve4 ,majores4--,valve large1 linear with parallel or slightly radiate stri and broad axial area4 ,gracillim4--,valve small1 stri parallel or nearly so2 axial area very narrow4 ,capitat4--,valve with capitate or rostrate ends2 stri radiate4 ,divergentes4--,stri strongly radiate4 ,brevistriat4--,stri short4 ,distantes4--,stri distant4 ,tabellari4--,stri radiate in the middle1 strongly convergent at the ends4 ,marin4--,marine forms4 ,,majores ,,pinnularia ,,major 7,,kuetz47 ,,wm4 ,,sm4 ,valve linear1 usually slightly gibbous in the middle and at the ends2 raphe oblique2 axial area less than one-third the width of valve1 convergent at the ends2 stri1 #g or #h in #aj 1 radiate in the middle1 convergent at the ends1 crossed by a narrow band4 ,l4 8 to #cjj 4 ,blue clay4 ,fresh water4 ,abundant at ,middletown1 ,delaware ,co4 7,t4 ,c4 ,palmer74 ,pl4 #bh1 ,fig4 #d4 ,fig4 #i1 ,pl4 #bi1 is one of a number of smaller forms which are difficult to determine1 approaching ,p4 viridis4 ,,pinnularia ,,major ,,var4 ,,pulchella ,n4 ,,var4 ,valve strongly gibbous in the middle and gradually widened to the rounded ends2 axial area broad1 less than one-third the width of the valve1 widened unilaterally in the middle2 stri1 #g in #aj 1 crossed by a band nearly as wide as the length of the cost and scarcely distinct4 ,l4 #bgc 4 #ajc,the central nodule is scarcely evident1 probably because it is not so thick as in other forms4 ,the outline is near to that of ,n4 mesogongyla and certain forms of ,n4 nobilis1 differing from the latter in the median line1 stri and band which is wider than that of ,p4 latevittata var4 domingensis ,cl4 ,hammonton ,pond1 ,n4 ,j4 ,pl4 #bh1 ,fig4 #b4 ,a very beautiful form which ,i cannot find described or figured4 ,it does not appear to be ,n4 major var4 turgidula ,cl41 which has a narrow band4 ,in the fossil deposit from ,hopkinton1 ,n4 ,h41 valves occur similar in outline but smaller4 ,,pinnularia ,,nobilis ,,ehr4 ,valve slightly gibbous in the middle and at the ends2 median line complex2 stri1 #d or #e in #aj 1 slightly convergent or parallel at the ends1 crossed by a band one-third as wide as the length of the stri4 ,l4 8 to #cej 4 ,blue clay4 ,fresh water4 ,pl4 #bh1 ,fig4 #a4 ,,pinnularia ,,dactylus ,,ehr4 ,valve broad1 linear1 slightly gibbous in the middle2 ends broad1 rounded2 median line not complex1 sinuous2 stri1 #d or #e in #aj 1 crossed by a very broad band4 ,l4 8 to #cjj 4 ,navicula gigas ,a4 ,s4 ,blue clay4 ,fresh water4 ,pl4 #bh1 ,fig4 #c4 ,forms occur which are with difficulty assigned to either nobilis or dactylus4 ,,pinnularia ,,dactylus ,,var4 ,,dariana 7,a4 ,s47 ,,cl4 ,valve linear-lanceolate1 obtuse2 axial area broad1 less than one-third the width of the valve2 stri1 #f in #aj 1 crossed by a broad band4 ,l4 #bbj 4 ,absecon1 ,n4 ,j4 ,pl4 #bi1 ,fig4 #c4 ,,pinnularia ,,dactylus ,,var4 ,,demerar ,,cl4 ,valve elliptical-lanceolate1 with sub-cuneate ends2 axial area lanceolate1 broad in the middle2 median line flexuose2 stri radiate throughout1 #f in #aj 4 ,l4 #aej 4 ,blue clay4 ,pl4 #bi1 ,fig4 #aj4 ,,pinnularia ,,gentilis 7,,donk47 ,,cl4 ,valve linear1 with rounded ends2 axial area about one-fourth the diameter of the valve2 stri radiate in the middle1 convergent at the ends1 #g in #aj 1 crossed by a broad indistinct band4 ,fresh water4 ,not common4 ,pl4 #bi1 ,fig4 #a4 ,,pinnularia ,,trigonocephala ,,cl4 ,valve linear1 gibbous in the middle and at the cuneate ends2 axial area wider between the middle and the ends1 dilated to an elliptical space in the middle2 stri1 #f in #aj 4 ,l4 #ade 4 ,blue clay4 ,pl4 #bi1 ,fig4 #h4 #ajd,,pinnularia ,,viridis ,,nitzsch ,valve linear-elliptical1 with rounded ends2 axial area narrow1 widened in the middle2 stri1 #f to #g in #aj 1 crossed by a band as wide as one-third the length of the stri4 ,common in fresh water4 ,pl4 #bi1 ,fig4 #b4 ,quite variable in size4 ,approaches ,p4 major by intermediate forms as in ,fig4 #i1 ,pl4 #bi4 ,,pinnularia ,,viridis ,,var4 ,,fallax ,,cl4 ,valve linear1 with rounded ends2 axial area narrow1 slightly widened in the middle2 stri sometimes unilaterally interrupted1 nearly parallel1 #aj in #aj 4 ,elm1 ,n4 ,j4 ,pl4 #bi1 ,fig4 #d4 ,in ,fig4 #b1 ,pl4 #cj1 a form is represented which corresponds closely to ,navicula viridis var4 ,b1 of ,wm4 ,smith4 ,it is given as synonymous with var4 fallax2 it is bilaterally interrupted4 ,blue clay4 ,,pinnularia ,,viridis ,,var4 8 ,valve linear-elliptical1 with rounded ends2 axial area narrow1 widened in the middle to a transverse fascia which is sometimes unilateral2 stri1 #ad1 in the middle1 divergent1 convergent at the ends and closer1 crossed by a narrow band4 ,l4 #de-fj 4 ,fascia sometimes absent or very narrow4 ,northbrook1 ,pa4 ,pl4 #cj1 ,fig4 #ag 7represents a form with wider area than usual74 ,,pinnularia ,,viridis ,,var4 ,,caudata ,n4 ,,var4 ,valve elliptical-lanceolate1 with sub-rostrate ends2 axial area narrow1 widened to an orbicular space in the middle2 stri radiate in the middle1 #aa-ab in #aj 1 convergent and closer at the ends1 crossed by a narrow band2 median line with very long terminal fissures2 terminal nodules noticeable because of the thickening of the edges of the terminal stri4 ,l4 #dc 4 ,fresh water1 ,newtown ,square4 ,not common4 ,pl4 #cj1 ,fig4 #ah4 ,,pinnularia ,,socialis 7,,palmer7 ,valve linear1 with rounded ends2 axial area broad1 one-third the width of the valve2 stri slightly radiate in the middle1 convergent at the ends1 elsewhere parallel1 #h in #aj 1 crossed by an indistinct band about one-third the length of the stri4 ,l4 #fj-abj 4 ,this species1 discovered by ,mr4 ,palmer near ,media1 ,pa41 is remarkable for the grouping of the frustules held with girdle sides together by a siliceous cementing of valve edges and enclosed in a common coleoderm4 ,the usual number included in a group is four1 but sometimes six or eight are noticed4 ,the frustules adhere near their ends and are so firmly fastened that boiling in nitric acid and bichromate of potash for fifteen minutes will not separate them4 ,navicula socialis ,palmer 7,proc4 ,acad4 ,nat4 ,sci41 ,phila41 #aiaj1 p4 #dfj1 ,pl4 #ce74 ,media1 ,pa4 ,pl4 #bi1 ,fig4 #e4 #aje,,pinnularia ,,stuarii ,,cl4 ,valve linear1 with rounded ends2 axial area broad1 less than one-third the width of the valve2 central area a transverse fascia2 stri1 #g in #aj 1 parallel except at the ends where they are slightly convergent2 median line flexuose1 with short1 terminal semicircular fissures4 ,l4 #he 4 ,port ,penn1 ,delaware ,river4 ,rare4 ,pl4 #bi1 ,fig4 #f4 ,,gracillim ,,pinnularia ,,molaris 7,,grun47 ,,cl4 ,valve very convex1 linear1 with sub-cuneate ends2 axial area narrow1 expanded in the middle to a transverse fascia reaching the margin2 stri divergent in the middle1 convergent at the ends1 #af in #aj 4 ,l4 #fj 4 ,fresh water4 ,pl4 #bi1 ,fig4 #ae4 ,,pinnularia ,,leptosoma ,,grun4 ,valve linear1 rounded at the ends2 axial area narrow2 central area a broad transverse fascia2 stri slightly divergent in the middle and convergent at the ends1 #ag in #aj in the middle1 closer at the ends4 ,l4 #ef 4 ,fresh water4 ,not common4 ,pl4 #cj1 ,fig4 #aj4 ,,capitat ,,pinnularia ,,mesolepta ,,ehr4 ,valve linear1 with triundulate margins and capitate ends2 axial area narrow1 widened in the middle2 stri divergent in the middle1 convergent at the ends1 about #ab in #aj 4 ,l4 #cd 4 ,common in fresh water4 ,pl4 #bi1 ,fig4 #ac4 ,,pinnularia ,,mesolepta ,,var4 ,,stauroneiformis ,,grun4 ,valve triundulate1 capitate2 axial area narrow1 widened in the middle to a transverse fascia1 broader at the margin2 stri strongly divergent in the middle and convergent at the ends1 #i-aj in #aj 4 ,l4 #gj 4 ,pavonia1 ,n4 ,j41 artesian well4 ,fresh water4 ,pl4 #cj1 ,fig4 #bj4 ,,pinnularia ,,subcapitata ,,greg4 ,valve linear or linear-elliptical1 with sub-capitate ends2 axial area distinct1 widened to a transverse fascia in the middle2 stri divergent in the middle1 convergent at the ends1 #ac in #aj 4 ,l4 #cb 4 ,fresh water4 ,pl4 #bi1 ,fig4 #bj4 #ajf,,pinnularia ,,subcapitata ,,var4 ,,paucistriata ,,grun4 ,valve linear-elliptical1 with rounded ends2 axial area gradually widened into a broad1 transverse fascia2 stri divergent in the middle1 convergent at the ends1 #aa-ab in #aj 4 ,l4 #dg 4 ,fresh water4 ,pl4 #cj1 ,fig4 #af4 ,,pinnularia ,,termes 7,,ehr47 ,a4 ,s4 ,valve linear1 with concave margins and rostrate-capitate ends2 axial area narrow1 widened in the middle to an orbicular or sub-quadrate space2 stri divergent in the middle1 scarcely1 if at all1 convergent at the ends1 #aj in #aj 4 ,pensauken1 ,n4 ,j41 artesian well4 ,pl4 #bi1 ,fig4 #ag4 ,this is1 ,i believe1 the form figured by ,schmidt 7,atlas1 ,pl4 #de1 ,fig4 #fg74 ,cleve refers it to ,pinnularia interrupta forma biceps1 in which the central space is rhomboid4 ,,pinnularia ,,termes ,,var4 ,,stauroneiformis ,v4 ,h4 ,valve linear1 with concave margins and capitate-rostrate ends2 axial area narrow1 widened into a rhomboidal fascia1 reaching the margin2 stri1 #aj in #aj 1 divergent in the middle1 convergent at the ends4 ,pinnularia interrupta forma stauroneiformis ,cl4 ,fresh water4 ,pl4 #bi1 ,fig4 #ad4 ,,pinnularia ,,appendiculata 7,,ag47 ,,cl4 ,valve linear1 with subcapitate ends2 axial area narrow2 central area a transverse fascia2 stri divergent in the middle1 convergent at the ends1 #af in #aj 4 ,l4 #dc 4 ,fresh water4 ,marl pits1 ,lenola1 ,n4 ,j4 7,palmer74 ,pl4 #bi1 ,fig4 #ah4 ,,pinnularia ,,braunii ,,grun4 ,valve linear-lanceolate1 with capitate ends2 axial area gradually widened toward the middle and expanded into a fascia reaching the margin2 stri divergent in the middle1 convergent at the ends1 #aa in #aj 4 ,l4 #eb 4 ,pensauken1 ,n4 ,j41 artesian well4 ,pl4 #bi1 ,fig4 #af4 ,,pinnularia ,,microstauron 7,,ehr47 ,,cl4 ,valve convex1 linear1 tapering to sub-cuneate or sub-rostrate ends2 axial area very narrow2 central area a broad fascia2 stri divergent in the middle1 convergent at the ends1 #ab in #aj 4 ,l4 #ce 4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #bi1 ,fig4 #ai4 ,this form does not exactly correspond to ,cleve's diagnosis1 as the ends are not broad4 ,all species in the group ,capitat are quite variable4 #ajg;,,divergentes ,,pinnularia ,,divergens ,,var4 ,,elliptica ,,grun4 ,valve linear1 with rounded ends2 axial area widened in the middle to a transverse fascia2 stri1 #i in #aj 1 divergent in the middle1 convergent at the ends4 ,l4 #aej 4 ,fresh water4 ,not common in this locality4 ,pl4 #ca1 ,fig4 #ac4 ,,pinnularia ,,cardinaliculus ,,cl4 ,valve linear1 with rounded ends2 axial area wide1 less than one-third the width of the valve1 expanded to a transverse fascia2 stri divergent in the middle and slightly convergent at the ends1 #i in #aj 4 ,l4 #ig 4 ,blue clay4 ,pl4 #cj1 ,fig4 #a4 ,as a rule1 the median fissures in ,pinnularia are turned inwards on the side of the longer edge of the terminal fissures1 but not always4 ,in this specimen the median fissures are turned slightly toward the side of the shorter edge of the terminal fissures4 ,,pinnularia ,,legumen ,,ehr4 ,valve linear1 with more or less triundulate margins and broad1 capitate ends2 axial area less than one-fourth the width of valve1 widened in the middle2 stri strongly divergent in the middle and convergent at the ends1 #aj in #aj 4 ,l4 #hd 4 ,fresh water4 ,may's ,landing1 ,n4 ,j4 ,pl4 #cj1 ,fig4 #c4 ,,pinnularia ,,legumen ,,var4 8 ,valve as in type1 but with a transverse fascia2 stri1 #aj in #aj 1 curved or bent near the ends4 ,l4 #hd 4 ,this form is not var4 florentina ,grun4 ,may's ,landing1 ,n4 ,j4 7with the type74 ,pl4 #cj1 ,fig4 #d4 ,,pinnularia ,,br,,bissonii 7,,kuetz47 ,,cl4 ,valve linear-elliptical1 with rounded ends2 axial area narrow1 widened into a transverse fascia which is usually broader at the ends2 stri divergent in the middle1 convergent at the ends1 about #ab in #aj 4 ,l4 #dj-fj 7,cl474 ,fresh water4 ,common4 ,pl4 #bi1 ,fig4 #ab2 ,pl4 #ca1 ,fig4 #aa4 ,variable in outline4 ,,pinnularia ,,mormonorum 7,,grun47 ,valve linear1 with rounded ends2 stri divergent in the middle1 convergent at the ends1 #aj in #aj 2 axial area rhombic-lanceolate1 widened to a fascia usually reaching the border4 ,l4 #fb 4 ,navicula mormonorum ,grun4 ,common near ,willistown1 ,pa4 ,this form is regarded by ,cleve as ,p4 brbissonii1 but the axial area appears to distinguish it4 ,the valves are sometimes narrowed in the middle4 ,pl4 #bi1 ,fig4 #aa4 #ajh;,,brevistriat ,,pinnularia ,,acrosph,,ria 7,,br,b47 ,,cl4 ,valve linear1 gibbous in the middle and at the ends2 axial area about half the width of the valve2 median line with approximate central pores2 median area punctate2 stri nearly parallel1 radiate at the ends1 #i in #aj 4 ,l4 #cb-ahj 7,cl474 ,blue clay4 ,recent1 fresh water4 ,pl4 #cj1 ,fig4 #g4 ,,pinnularia ,,acrosph,,ria ,,var4 ,,turgidula ,,grun4 8 ,valve strongly gibbous in the middle2 ends rounded2 stri1 #ab-ac in #aj 4 ,l4 #ed 4 ,blue clay1 ,gloucester1 ,n4 ,j41 artesian well4 ,pl4 #cj1 ,fig4 #h4 ,,pinnularia ,,blandita ,n4 ,,sp4 ,valve linear1 gibbous in the middle1 and with rounded ends2 stri radiate in the middle1 convergent at the ends1 #ac in #aj 2 axial area about one-fourth the width of the valve1 widened in the middle2 median line with small semicircular terminal fissures4 ,l4 #fe 4 ,pavonia1 ,n4 ,j41 artesian well4 ,rare4 ,pl4 #cj1 ,fig4 #be4 ,,pinnularia ,,parva 7,,ehr47 ,,cl4 ,,var4 8 ,valve linear1 tapering to the subcapitate ends2 axial area broad1 lanceolate2 median line with approximate central pores and semicircular terminal fissures2 stri slightly divergent in the middle and convergent at the ends1 #ab in #aj 4 ,l4 #eh 4 ,differs from the type in having finer stri4 ,atco1 ,n4 ,j4 ,pl4 #cj1 ,fig4 #ad4 ,,pinnularia ,,nodosa ,,forma ,,capitata ,,cl4 ,valve triundulate1 with capitate ends2 axial area about one-fourth the width of valve2 stri parallel1 convergent at the ends1 #aj in #aj 1 sometimes interrupted in the middle4 ,l4 #dg 4 ,fresh water4 ,common4 ,pl4 #cj1 ,figs4 #ae and #ai4 ,,pinnularia ,,polyonca 7,,br,b47 ,,lewis ,valve with triundulate margins1 more inflated in the middle1 with capitate ends2 axial area very broad2 stri marginal1 short1 #i in #aj 1 divergent in the middle1 convergent at the ends4 ,l4 #ig 4 ,kirkwood ,pond1 ,n4 ,j4 ,pl4 #cj1 ,fig4 #ba4 ,the description of ,kuetzing 7,species ,algarum1 p4 #he71 where he states that the margins are triundulate1 the median inflation larger1 apices rounded-capitate1 appears to sufficiently distinguish this species1 which ,i believe to be the same as ,brun's ,navicula peripunctata1 except that the form figured 7,espces ,nouvelles1 ,pl4 #af1 ,fig4 #aa7 is interrupted in the middle1 a common variation in these forms4 ,cleve makes ,navicula polyonca ,brb4 equal ,pinnularia mesolepta1 but at the same time he considers ,lewis' form and also ,brun's as equivalent to ,navicula formica ,ehr41 and calls it ,pinnularia nodosa var4 formica ,ehr4 ,p4 mesolepta has a narrower area than nodosa4 ,i adhere to ,lewis' identification1 as in any case it is the form here figured and is nearly1 if not quite1 the same as ,brun's species4 #aji;,,distantes ,,pinnularia ,,lata 7,,br,b47 ,,wm4 ,,sm4 ,valve linear-elliptical1 broad2 axial area broad1 widened in the middle2 stri slightly radiate in the middle1 #c in #aj 2 median line oblique1 the terminal fissures hook-shaped4 ,l4 #hf 4 ,blue clay4 ,not uncommon4 ,pl4 #cj1 ,fig4 #bc4 ,,pinnularia ,,borealis ,,ehr4 ,valve linear1 with rounded or sub-truncate ends2 axial area about one-fourth the width of the valve1 widened in the middle2 median line with large hook-shaped terminal fissures2 stri1 #d or #e in #aj 4 ,l4 #ed 4 ,blue clay4 ,occasional in fresh water in a smaller form4 ,specimens occur intermediate between ,p4 lata and ,p4 borealis4 ,pl4 #cj1 ,fig4 #bb2 ,pl4 #ca1 ,fig4 #ab4 ,,pinnularia ,,borealis ,,var4 ,,scalaris 7,,ehr47 ,,cl4 ,valve narrow1 linear2 axial area broad1 widened into a transverse fascia2 stri1 #h in #aj 4 ,l4 #cb 4 ,fresh water4 ,pl4 #cj1 ,fig4 #bd4 ,,tabellari ,,pinnularia ,,stomatophora 7,,grun47 ,,cl4 ,valve linear1 with rounded ends2 axial area less than one-third the width of the valve1 gradually widened in the middle to a transverse fascia2 on each side of the central nodule is a lunate space2 stri divergent in the middle1 convergent at the ends1 #ac in #aj 2 terminal fissures very long1 bayonet shaped4 ,l4 #ge 4 ,cleve describes a variety continua as not interrupted4 ,in some forms the fascia is marked by very faint1 short stri on the margin4 ,fresh water4 ,newtown ,square4 ,pl4 #cj1 ,fig4 #ab4 ,,pinnularia ,,gibba 7,,kuetz47 ,v4 ,h4 ,valve linear1 tapering to the subcapitate ends2 axial area dilated in the middle2 stri1 #aj-aa 1 divergent in the middle1 convergent at the ends4 ,l4 #hj 4 ,fresh water4 ,pl4 #cj1 ,fig4 #e4 ,,pinnularia ,,mesogongyla 7,,ehr47 ,,cl4 ,valve linear1 gibbous in the middle1 ends subcapitate2 axial area narrow1 widened in the middle to a large orbicular space2 stri strongly divergent in the middle1 convergent at the ends1 #aa in #aj 4 ,l4 #fj 4 ,fresh water4 ,common4 ,pl4 #cj1 ,fig4 #f4 #aaj,,pinnularia ,,stauroptera 7,,grun47 ,,cl4 ,valve linear1 with slightly triundulate margins tapering to the subcapitate ends2 axial area more than one-third the width of the valve1 slightly widened in the middle2 median line with approximate central pores and semicircular terminal fissures2 stri divergent in the middle1 convergent at the ends1 #aa in #aj 4 ,l4 #hb 4 ,may's ,landing1 ,n4 ,j4 ,pl4 #cj1 ,fig4 #ac4 ,some of the forms are more triundulate than the specimen figured4 ,,pinnularia ,,stauroptera ,,var4 ,,interrupta ,,cl4 ,valve linear1 tapering to the subcapitate ends2 axial area broad1 widened in the middle to a transverse fascia2 stri divergent in the middle1 convergent at the ends1 #aj in #aj 2 median pores approximate4 ,l4 #aah 4 ,schuylkill ,river4 ,pl4 #cj1 ,fig4 #aa4 ,,pinnularia ,,tabellaria 7,,ehr47 ,,cl4 ,valve linear1 gibbous in the middle and tapering to the subcapitate ends2 axial area about one-third the width of the valve1 widened in the middle2 median line with approximate central pores and bayonet-shaped terminal fissures2 stri sometimes unilaterally interrupted1 divergent in the middle1 strongly convergent at the ends1 #i in #aj 4 ,l4 #ach 4 ,blue clay4 ,rare4 ,pl4 #cj1 ,fig4 #i4 ,the form here figured has coarser stri than in the type which is also usually more capitate4 ,p4 legumen has triundulate margins1 ,p4 mesogongyla has an orbicular space1 while ,p4 gibba has the space widened4 ,according to ,cleve1 ,p4 gibba has approximate central pores1 as has also ,p4 mesogongyla4 ,in what ,i have considered to be ,p4 legumen1 the central pores are more approximate than in the other two species mentioned4 ,in fact1 all of the three resemble each other closely1 and are variously named by different authors4 ,the form of ,p4 gibba here figured1 which may be ,p4 stauroptera1 is not the typical form of ,wm4 ,smith1 which has a narrow area and central space4 ,there are1 however1 among the typical specimens in ,h4 ,l4 ,smith's ,type ,slide ,no4 #bge1 smaller valves which show a resemblance4 ,,marin ,,pinnularia ,,rectangulata 7,,greg47 ,,cl4 ,valve linear1 with abruptly rounded ends2 axial area very narrow2 central area large1 somewhat quadrate2 stri1 #g-h in #aj 4 ,l4 #gh 4 ,navicula rectangulata ,greg4 ,shark ,river1 ,n4 ,j4 ,pl4 #bi1 ,fig4 #g4 #aaa;,,epithemia ,,br,b4 7#ahch7 7epithema1 a cover or lid7 ,frustules epiphytic1 solitary1 sometimes geminate1 adherent on the ventral side at the ends2 in zone view rectangular1 sometimes tumid in the middle4 ,valve arcuate1 having an interior costate stratum or transverse septa extending to the girdle1 often detached1 and an exterior valve surface with transverse rows of puncta4 ,central and terminal nodules not easily seen2 in some species a true raphe is indicated4 ,the resemblance between ,epithemia and ,eunotia has been already mentioned4 ,in the shape and striation of the valves there is an approach to ,cymbella4 ,the genus is divided into two groups1 one in which the cost alternate with double rows of puncta1 as in ,e4 turgida1 and the other in which the rows of puncta are more than two4 ,the endochrome usually consists of a band lying along the ventral zone and extending in two flaps on the valves4 ,,epithemia ,,turgida 7,,ehr47 ,,kuetz4 ,valve arcuate1 with ends subcapitate2 cost radiate1 #d in #aj 1 alternating with double rows of puncta4 ,median nodule central1 the raphe curved toward the ventral edge which it closely follows4 ,parasitic on alg4 ,very common in fresh water1 especially in ponds4 ,in the figure the valve is asymmetrical with respect to the transverse axis1 an unusual condition4 ,pl4 #ca1 ,fig4 #ad4 ,,epithemia ,,argus ,,kuetz4 ,valve with dorsal margin convex1 and ventral margin nearly straight2 ends rounded1 constricted2 cost robust1 alternating with more than two rows of puncta2 zone view rectangular1 the thickened ends of the cost forming large nodules in a row along the edge of the valve next to the connecting zone4 ,cystopleura argus 7,ehr47 ,kunze4 ,common in fresh water4 ,pl4 #ca1 ,figs4 #ae and #ba4 ,,epithemia ,,argus ,,var4 8 ,valve strongly arcuate on the dorsal side and concave on the ventral2 tapering to the rounded but not produced ends2 cost at unequal distances1 about #b in #aj 2 granules in transverse rows1 #h in #aj 4 ,l4 #ajj 4 ,pensauken1 ,n4 ,j41 artesian well4 ,pl4 #ca1 ,fig4 #af4 ,,epithemia ,,muelleri ,a4 ,s4 8 ,valve broad1 convex1 slightly arcuate1 with obtuse1 somewhat constricted apices2 cost about #d in #aj 2 stri1 #ab-ad in #aj 2 in zone view the outline is rectangular1 slightly tumid in the middle4 ,l4 #gh 4 ,blue clay4 ,pl4 #ca1 ,fig4 #ag4 #aab;,,epithemia ,,zebra ,,var4 ,,proboscidea 7,,kuetz47 ,,grun4 ,valve convex on the dorsal1 concave on the ventral side2 cost1 #c-d in #aj 1 slightly radiating2 apices recurved1 capitate4 ,blue clay4 ,pl4 #ca1 ,fig4 #ah4 ,,epithemia ,,gibberula ,,var4 ,,producta ,,grun4 ,valve narrow1 lunate1 with produced and arcuate apices2 cost radiate1 #c-d in #aj 2 stri1 #af-ah in #aj 1 punctate4 ,l4 #eh 1 usually smaller4 ,blue clay4 ,pl4 #ca1 ,fig4 #ai4 ,,epithemia ,,musculus ,,kuetz4 ,valve short1 strongly arcuate on the dorsal1 concave on the ventral side2 apices slightly produced2 cost radiate1 about #e in #aj 2 stri1 #ae in #aj 1 punctate4 ,l4 #bj-fj 4 ,shark ,river1 ,n4 ,j4 ,pl4 #ca1 ,fig4 #bj4 ,,epithemia ,,musculus ,,var4 ,,constricta 7,,br,b47 ,v4 ,h4 ,frustule elliptical1 slightly constricted in the middle4 ,valve convex on the dorsal1 straight on the ventral side2 cost about #d in #aj 2 stri about #ah in #aj 1 finely punctate4 ,l4 #de 4 ,epithemia succinta ,brb4 ,new ,rochelle1 ,n4 ,y4 ,pl4 #ca1 ,fig4 #bb4 ,,rhopalodia ,,mueller 7#ahhe7 7,rhopalodes1 like a war club7 ,frustule in zone view linear1 linear-elliptical 7in our species71 or clavate4 ,valve reniform or lunate2 a raphe1 not visible in some species in the usual position of the valve1 is found along the convex edge or keel4 ,median and terminal nodules1 although very small1 can be determined4 ,the name is more appropriate to the ,african species which are clavate4 ,two species only are found in this locality4 ,the chief distinction between ,epithemia and ,rhopalodia is in the position of the raphe and the nodules4 ,in ,r4 gibba and ,r4 ventricosa the cost are parallel and not radiate since the valves are not lunate4 ,chromatophore a single band irregularly divided4 ,,rhopalodia ,,gibba 7,,kuetz47 ,,mueller ,valve linear1 arcuate on the dorsal1 straight on the ventral side1 reflexed at the extremities4 ,cost1 #f-g in #aj 2 stri about #ad in #aj 4 ,l4 #hj-bjj 4 ,fresh water4 ,common4 ,pl4 #ca1 ,fig4 #bc4 ,in this species the raphe and nodules can be seen only when the valve is examined at right angles to its usual position4 #aac,,rhopalodia ,,ventricosa 7,,kuetz47 ,,mueller ,valve gibbous in the middle on the dorsal side1 straight on the ventral side1 with reflexed apices2 cost1 #g in #aj 2 stri1 #ad-af in #aj 4 ,l4 #dj-ajj 4 ,the median nodule appears as a minute depression in the middle of the dorsal side4 ,the two species usually occur together4 ,epithemia gibba var4 ventricosa ,kuetz4 ,pl4 #ca1 ,fig4 #bd4 ,,surirelloide ,the ,surirelloide are usually understood to include the genera ,surirella1 ,podocystis1 ,cymatopleura and ,campylodiscus1 all of which resemble each other more or less1 either in having a keel or markings like the divisions of the keel in ,surirella and a median line1 or pseudoraphe4 ,the genus ,nitzschia also has a keel1 but it does not border each side of the valve as in ,surirella1 being found either near one margin or between it and the centre4 ,certain of the ,surirell are allied to the group ,tryblionella of the ,nitzschi1 while forms of ,stenopterobia are distinguished with difficulty from the group ,sigmata4 ,the following arrangement1 therefore1 is intended to include all genera having a keel or something which resembles it4 ,hantzschia4--,valve asymmetrical2 keels of the two valves opposite each other4 ,nitzschia4--,valve asymmetrical2 keels not 7usually7 opposite each other4 ,surirella4--,valve usually symmetrical2 a keel on each border4 ,cymatopleura4--,valve without an elevated keel1 but with markings like those of ,surirella2 undulated in zone view4 ,campylodiscus4--,valves saddle-shaped4 ,,hantzschia ,,grun4 7#ahgg7 7named after ,c4 ,a4 ,hantzsch7 ,valve arcuate1 with rostrate ends2 keel puncta short1 prolonged into cost or extending across the valve2 median nodule rudimentary2 the keels of the two valves opposite each other4 ,distinguished from ,nitzschia chiefly by the position of the keels4 ,according to ,mereschkowsky1 however1 two species of ,nitzschia1 ,n4 lanceolata and ,n4 spectabilis1 show the same peculiarity4 ,chromatophores four1 two on each of the zones 7,mereschkowsky74 ,,hantzschia ,,amphioxys 7,,ehr47 ,,grun4 ,valve slightly arcuate1 with rostrate apices2 keel puncta1 #h in #aj 2 stri transverse1 #af-ah in #aj 1 punctate4 ,l4 #fj 4 ,quite variable4 ,fresh water4 ,pl4 #cb1 ,fig4 #i4 #aad;,,hantzschia ,,amphioxys ,,var4 ,,major ,,grun4 ,valve as in type1 but the keel puncta are #e in #aj and the stri are #aa-ab in #aj 4 ,l4 #ga 4 ,h4 amphioxys var4 major ,grun4 is stated to be #abj in length4 ,the present form is smaller but corresponds in puncta and striation4 ,van ,heurck remarks that it approaches ,h4 virgata4 ,abundant in sand ripples on the beach at ,cape ,may1 ,n4 ,j4 ,pl4 #ci1 ,fig4 #d4 ,fig4 #f1 ,pl4 #ci1 is drawn from an authentic specimen of ,wm4 ,smith's ,nitzschia amphioxys1 from ,england1 and is introduced for comparison4 ,the central nodule is not evident4 ,fig4 #c1 ,pl4 #ci1 is from a specimen from an unknown locality4 ,the keel puncta are #f and the stri #af in #aj 4 ,,hantzschia ,,virgata 7,,roper7 ,,grun4 ,valve arcuate on the dorsal side1 nearly straight on the ventral side1 with rostrate1 recurved apices2 keel puncta prolonged to one-third the width of the valve1 #d in #aj 2 transverse stri1 #i-aj in #aj 4 ,l4 #aae 4 ,shark ,river1 ,n4 ,j4 7,kain74 ,i have not been able to find this form on our coast4 ,the figure is drawn from a specimen from another locality4 ,pl4 #cb1 ,fig4 #bc4 ,,hantzschia ,,marina 7,,donk47 ,,grun4 ,valve with dorsal margin slightly arcuate1 ventral margin straight2 apices rostrate and recurved2 keel puncta1 #f in #aj 1 prolonged into cost across the entire valve2 transverse stri1 #ab in #aj 1 in double rows of alternating puncta between the cost4 ,l4 #ajf 4 ,epithemia marina ,donkin4 ,along the coast4 ,pl4 #cb1 ,fig4 #bb4 ,,nitzschia ,,hassall 7#ahde71 em4 ,,grun4 7#ahhj7 7named after ,christian ,l4 ,nitzsch1 of ,halle7 ,frustules usually free1 sometimes enclosed in tubes or united into a filament4 ,valves keeled1 the keels of the two valves usually diagonally opposite 7see ,hantzschia72 keel puncta short or prolonged4 ,according to ,mereschkowsky1 there are at least two endochrome plates placed transversely on the zones2 sometimes there are from four to six plates1 in one species twenty granules and in another no trace of any endochrome whatever4 ,the following analysis is that of ,grunow as given in ,cleve and ,grunow's ,arctic ,diatoms1 and adopted and illustrated by ,van ,heurck in his ,synopsis4 ,,groups #a4 ,tryblionella4--,keel very excentric1 valve often folded2 keel puncta indistinct1 usually the same in number as the stri4 #b4 ,panduriformes4--,valve broad1 constricted in the middle1 with more or less evident fold2 keel very near the edge2 keel puncta quite evident or apparently wanting4 #aaec4 ,apiculat4--,keel very near the edge2 valve linear or somewhat narrower in the middle2 stri on the longitudinal fold fainter than on the remaining surface1 or wanting2 puncta not in quincunx4 #d4 ,pseudo-,tryblionella4--,keel more or less close to the edge2 valve with a more or less deep longitudinal fold over which the stri are spread in the same way as over the remaining surface2 keel puncta always distinct4 #e4 ,circumsut4--,valve with more or less wide longitudinal fold2 keel very excentric2 keel puncta quite evident2 surface of valve irregularly punctate and also traversed by rows of delicate puncta which belong to a different layer of the valve4 #f4 ,dubi4--,like the group ,pseudo-,tryblionella1 but the valves are not so much folded2 frustules sometimes narrowed in the middle4 ,the separation of species is difficult and1 in part1 doubtful4 ,keel excentric4 #g4 ,bilobat4--,like the group ,dubi1 but with more central keel and so forming a transition to the group ,pseudo-,amphiprora2 valves without longitudinal folds4 #h4 ,pseudo-,amphiprora4--,valve with quite central1 sharp keel1 arcuate1 without longitudinal fold2 keel puncta always evident2 frustule narrowed in the middle with more or less marked central nodule4 ,includes two species not found in this locality4 #i4 ,perrya4--,valve arched with very sharp central keel2 not narrowed in the middle2 keel puncta mostly on short or long lines which are sometimes interrupted4 ,includes six species not found in this locality4 #aj4 ,epithemioide4--,keel excentric2 keel puncta extended into cost across the entire valve4 #aa4 ,grunowia4--,as in the group ,epithemioide1 except that the cost are shorter1 not extending across the valve2 keel very excentric4 #ab4 ,scalares4--,like ,grunowia1 but with sharper1 somewhat excentric keel2 transverse section of frustule quadrangular4 #ac4 ,insignes4--,like ,scalares1 but with more central keel so that many of the forms are near the group ,perrya2 frustule somewhat sigmoid4 #ad4 ,bacillaria4--,keel central or nearly so2 valve somewhat arched2 keel sharp1 as in the group ,insignes4 #ae4 ,vivaces4--,keel moderately excentric2 valve1 according to position1 semi-lanceolate1 with keel puncta in short rows1 or lanceolate with quite central keel4 ,the valves have in many positions a resemblance to ,hantzschia1 so that ,n4 vivax frequently becomes confounded with a form of ,h4 amphioxys4 ,the median keel puncta are not distant and a central nodule is not evident as is the case in all species of ,hantzschia4 #af4 ,spathulat4--,like the group ,bacillaria1 but usually with very delicate striated valves2 keel in valve view usually bordered with two parallel lines4 #ag4 ,dissipat4--,like ,vivaces and ,spathulat1 but with smaller central keel and without parallel lines4 ,valves usually small1 very delicately striated2 no central nodule4 #ah4 ,sigmoide4--,keel quite central2 no parallel lines2 frustule sigmoid2 valve without longitudinal furrow2 keel puncta not extended2 no central nodule evident4 #ai4 ,sigmata4--,like ,sigmoide1 but with a more excentric keel4 #bj4 ,obtus4--,like ,sigmata1 with a more or less excentric keel which has in the middle a small bending to the inside2 middle keel puncta somewhat more distant than the others1 and between them a central nodule evident4 #aafba4 ,spectabiles4--,valve large1 slightly arcuate1 with excentric keel2 no longitudinal folds2 keel puncta somewhat extended over the valve but much less than in the group ,insignes1 and often scarcely perceptible4 #bb4 ,lineares4--,keel somewhat excentric1 but less than in ,spectabiles2 frustule straight1 sometimes a little constricted in the middle1 so that a transition is shown to the groups ,dubi and ,bilobat4 ,valve without longitudinal fold2 keel puncta round or somewhat angular1 scarcely extended4 #bc4 ,lanceolat4--,valve lanceolate1 linear-lanceolate or rarely elliptical1 with very excentric keel2 not folded2 keel puncta not extended4 #bd4 ,nitzschiella4--,valve with excentric keel and long1 produced apices4 ,,tryblionella ,,nitzschia ,,tryblionella ,,hantzsch ,valve elliptical-lanceolate1 with subacute apices2 longitudinal fold well marked2 stri coarse1 transverse1 #e in #aj 2 indistinct puncta intermediate between the stri4 ,l4 #de 4 ,quite variable4 ,blue clay4 ,pl4 #cb1 ,fig4 #h4 ,,nitzschia ,,granulata ,,grun4 ,valve elliptical or elliptical-lanceolate2 stri in double rows1 each row of three or four small puncta along the margin and rows of large puncta about #f in #aj across the valve4 ,l4 #bh-dd 4 ,blue clay4 ,along the coast4 ,pl4 #cb1 ,fig4 #c4 ,,nitzschia ,,navicularis 7,,br,b47 ,,grun4 ,valve elliptical-lanceolate1 with acute apices2 stri on one side a double row of large and small puncta1 and on the other side radiate short rows of large puncta1 #g in #aj 2 middle of valve hyaline4 ,l4 #ce-fj 4 ,blue clay4 ,not common4 ,pl4 #cb1 ,fig4 #d4 ,,nitzschia ,,compressa 7,,bail47 ,valve elliptical-lanceolate1 sometimes acuminate2 stri1 #f or #g in #aj 1 coarsely punctate4 ,l4 #ef 4 ,pyxidicula compressa ,bailey4 ,nitzschia punctata 7,wm4 ,sm47 ,grun4 ,tryblionella punctata ,wm4 ,sm4 ,common along the coast4 ,pl4 #ci1 ,fig4 #g4 ,var4 minor 7,h4 ,l4 ,smith74--,valve acuminate2 stri1 #h in #aj 4 ,l4 #bb 4 ,pyxidicula compressa var4 minor ,h4 ,l4 ,smith1 ,type ,slide ,no4 #dca4 ,pl4 #ci1 ,fig4 #h4 ,the smaller forms occur northward1 while the larger are found southward4 ,this is unquestionably ,bailey's form1 as indicated by his figure and by the fact that it is found everywhere along the coast4 ,wm4 ,smith's ,t4 punctata is the same species1 although the puncta are smaller4 #aag,,panduriformes ,,nitzschia ,,panduriformis ,,greg4 ,valve elliptical1 constricted in the middle1 with sub-cuneate apices2 longitudinal fold1 with a punctate longitudinal line2 stri transverse and oblique1 #ae in #aj 2 keel puncta1 #f in #aj 4 ,l4 #ajh 4 ,along the coast4 ,more often found southward4 ,pl4 #ci1 ,fig4 #b4 ,,nitzschia ,,panduriformis ,,var4 ,,minor ,,grun4 ,valve elliptical1 constricted in the middle1 with cuneate apices2 keel puncta1 #i in #aj 2 stri in transverse and oblique lines about #bj in #aj 2 longitudinal fold bordered by a punctate line4 ,l4 #cd 4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #cb1 ,fig4 #e4 ,the var4 continua ,grun4 is reported as occurring in ,shark ,river4 ,it varies in having the longitudinal fold punctate4 ,it is also usually smaller than var4 minor4 ,,apiculat ,,nitzschia ,,apiculata 7,,greg47 ,,grun4 ,valve oblong-linear1 with cuneate-apiculate apices2 stri punctate1 apparently interrupted or pervious1 about #ah in #aj 4 ,l4 #bf 4 ,chester ,river1 ,md4 ,pl4 #cb1 ,fig4 #f4 ,the puncta are continued across the valve1 but are less distinct on the fold4 ,the figure shows the entire frustule with the fold on each valve4 ,the valves are sometimes slightly constricted4 ,,nitzschia ,,acuminata 7,,wm4 ,,sm47 ,,grun4 ,valve linear1 sometimes slightly constricted in the middle1 with acuminate apices2 longitudinal fold entirely without or with indistinct stri2 keel puncta not evident2 stri1 #ad-ae in #aj 4 ,l4 #hb 4 ,port ,penn1 ,delaware ,river4 ,pl4 #cb1 ,fig4 #ac4 ,,nitzschia ,,plana ,,wm4 ,,sm4 ,valve linear2 apices acute1 slightly constricted in the middle2 longitudinal fold further from the keel than the margin1 broad1 with scattered puncta2 stri subtle1 irregular1 interrupted1 about #ah in #aj 2 keel puncta oblong1 #c-f in #aj 4 ,l4 #ajj-agj 4 ,blue clay4 ,along the coast4 ,pl4 #cb1 ,fig4 #b4 #aah,,pseudo-,,tryblionella ,,nitzschia ,,litoralis ,,var4 ,,delawarensis ,,grun4 ,valve linear1 with obtusely rounded cuneate ends1 scarcely1 if at all1 constricted in the middle2 longitudinal fold wide2 keel puncta1 #e or #f in #aj 1 sometimes confluent2 stri obscure1 about #ba in #aj 4 ,l4 #ge 4 ,delaware ,river4 ,pl4 #cb1 ,fig4 #ab4 ,this form is drawn from a slide of ,christian ,febiger containing an abundance of specimens from ,delaware ,city1 and marked ,nitzschia dubia4 ,,circumsut ,,nitzschia ,,circumsuta 7,,bail47 ,,grun4 ,valve elliptical1 sometimes more than #bjj in length2 longitudinal fold more or less conspicuous2 keel puncta about #d in #aj 1 the middle distant with the appearance of a nodule2 stri irregular1 subtle1 finely punctate1 frequently interrupted4 ,surirella circumsuta ,bail4 ,tryblionella scutellum ,wm4 ,sm4 ,common in brackish water4 ,pl4 #cb1 ,fig4 #a4 ,,dubi ,,nitzschia ,,dubia ,,wm4 ,,sm4 ,valve linear1 scarcely1 if at all1 constricted in the middle1 with cuneate1 produced1 apiculate apices1 somewhat recurved2 keel very excentric2 puncta sometimes partly prolonged1 about #i in #aj 2 stri1 #bj-bd in #aj 4 ,l4 #ic 4 ,reported from along the ,new ,jersey coast4 ,i have not seen it4 ,it is generally regarded as fresh-water4 ,slides sometimes labelled ,n4 dubia are in reality ,n4 litoralis var4 delawarensis4 ,pl4 #ci1 ,fig4 #e4 ,the figure is drawn from a specimen from another locality4 ,,bilobat ,,nitzschia ,,bilobata ,,wm4 ,,sm4 ,valve linear-lanceolate1 constricted in the middle1 apiculate at the ends2 keel puncta #f in #aj 1 prolonged unequally across part of the valve1 the two median sub-remote2 stri1 #af in #aj 4 ,frustule oblong1 truncate1 constricted in the middle4 ,l4 #abj 4 ,shark ,river1 ,n4 ,j41 ,chester ,river1 ,md4 ,pl4 #cb1 ,figs4 #aj and #aa4 ,,epithemioide ,,nitzschia ,,epithemioides ,,grun4 ,valve linear1 with cuneate1 rostrate apices2 slightly constricted on the keel side2 keel puncta1 #h or #i in #aj 1 extending as cost across the valve2 stri delicate1 #bb in #aj 4 ,l4 #dg 4 ,brackish water1 ,long ,island ,sound4 ,pl4 #cb1 ,fig4 #ba4 #aai;,,grunowia ,,nitzschia ,,tabellaria ,,grun4 ,valve rhomboidal1 inflated in the middle2 apices produced2 keel puncta extend in cost across half of the valve1 #g in #aj 2 stri transverse1 about #bb in #aj 4 ,l4 #bj 4 ,dimerogramma sinuatum ,thwaites4 ,nitzschia sinuata var4 tabellaria 7,grun47 ,v4 ,h4 ,schuylkill ,river4 ,not common4 ,pl4 #cb1 ,fig4 #g4 ,,scalares ,,nitzschia ,,scalaris 7,,ehr47 ,,wm4 ,,sm4 ,valve linear1 with obtusely conical apices2 cost transverse1 extending more or less to one-third the width of the valve1 #c or #d in #aj 2 stri1 #i or #aj in #aj 1 punctate4 ,length of valve quite variable1 up to #dhj 7,cleve74 ,a well-known form1 abundant in salt marshes and more or less brackish water4 ,pl4 #cc1 ,fig4 #f4 7,to the right of the figure is an outline of the valve reduced one-third47 ,,insignes ,,nitzschia ,,insignis ,,greg4 ,valve nearly linear or linear-lanceolate2 apices broad1 slightly produced1 obtuse2 keel puncta extended into short cost1 #d or #e in #aj 2 stri about #ad in #aj 4 ,length variable up to #djj 4 ,delaware ,bay4 ,pl4 #cc1 ,fig4 #h4 ,,bacillaria ,,nitzschia ,,paxillifer 7,o4 ,f4 ,,mueller7 ,,heiberg ,frustules united in a filament1 afterwards free2 valve lanceolate with nearly central keel2 keel puncta1 #g-i in #aj 2 stri about #ba in #aj 4 ,l4 #aaj 4 ,vibrio paxillifer ,o4 ,f4 ,mueller4 ,bacillaria paradoxa ,gmelin4 ,nitzschia paradoxa 7,gmelin7 ,grun4 ,brackish water or streams subject to its influence4 ,pl4 #cc1 ,figs4 #ac and #ad4 ,otto ,frederick ,mueller1 in #aghf1 published at ,copenhagen a work on ,infusorial ,animalcules1 including a description of a ,vibrio which he named paxillifer1 obviously alluding to the partially-extended frustules bearing at the end a tablet-like bundle4 ,two years later1 ,gmelin described the same form as ,bacillaria paradoxa1 a name still used4 ,heiberg1 however1 in #ahfc1 placed the form under ,nitzschia where it properly belongs and called it ,nitzschia paxillifer 7,o4 ,f4 ,mueller74 ,i have adopted ,heiberg's name4 ,perhaps the most remarkable of all diatoms4 ,many species possess the power of motion1 which1 however1 is evident only in the free frustule4 ,in ,n4 paxillifer1 the movement of the frustules occurs without the loss of continuity or adherence to each other1 so that1 while at one time the adnate frustules form a narrow filament1 like that of ,fragilaria1 at another #abjtime they move laterally to their extreme length and form a thread of frustules adherent at their ends1 later resuming their original position4 ,the motion is repeated at intervals of from five to ten seconds4 ,no satisfactory explanation of the movement has ever been made4 ,in the filamentous form the frustules adhere to water-plants4 ,,vivaces ,,nitzschia ,,fluminensis ,,grun4 ,valve lanceolate1 apices produced2 keel puncta1 #d-f in #aj 1 partly extended in short cost2 stri transverse1 #ad-ae in #aj 1 punctate2 keel without a pseudo-nodule4 ,l4 #gc 4 ,common at ,greenwich ,point1 ,philadelphia4 ,pl4 #cb1 ,fig4 #af4 ,the form here figured is smaller than the type1 which is from #acj-afj in length4 ,,spathulat ,,nitzschia ,,spathulata ,,br,b4 ,frustule linear1 truncate1 dilated at the ends2 zone with longitudinal folds2 valve lanceolate1 keel central2 apices acute1 with an elevated appendage2 keel puncta1 #e-f in #aj 2 stri very fine4 ,l4 #ef 4 ,atlantic ,city and ,cape ,may1 ,n4 ,j4 7,lewis74 ,pl4 #dj1 ,fig4 #c4 ,,dissipat ,,nitzschia ,,dissipata 7,,kuetz47 ,,grun4 ,valve lanceolate1 with sub-rostrate apices2 keel excentric2 keel puncta about #f in #aj 2 stri1 #ad in #aj 4 ,l4 #bj-dj 4 ,fresh and brackish water4 ,pl4 #dj1 ,fig4 #g4 ,,sigmoide ,,nitzschia ,,macilenta ,,greg4 ,frustule sigmoid1 truncate at the ends2 valve linear1 with sub-acute apices and nearly central keel2 keel with #e-f puncta in #aj 2 stri obscure1 about #be to #bh 787 in #aj 4 ,length variable1 up to #dij 4 ,as the valve is usually seen when the keel is on the margin1 the outline 7reduced one-third1 shown to the left of the figure7 is1 as a rule1 sigmoid4 ,delaware ,bay4 ,pl4 #cc1 ,fig4 #g4 ,,nitzschia ,,vermicularis 7,,kuetz47 ,,hantzsch ,valve linear1 sigmoid1 attenuated toward the obtuse ends2 keel puncta1 #i in #aj 1 quite distinct2 stri very fine4 ,l4 #aje 4 ,fresh-water pools4 ,pl4 #cb1 ,fig4 #bd2 ,pl4 #cc1 ,fig4 #i4 #aba,,sigmata ,,nitzschia ,,sigma 7,,kuetz47 ,,wm4 ,,sm4 ,frustule linear1 sigmoid2 valve linear1 slightly sigmoid1 tapering to the sub-acute apices2 keel excentric1 puncta1 #h in #aj 2 stri1 #bj-bd in #aj 4 ,l4 to #bej 4 ,along the coast4 ,pl4 #ci1 ,fig4 #ac4 ,,nitzschia ,,sigmatella ,,greg4 ,valve linear1 sigmoid1 slightly attenuated toward the obtuse apices2 keel excentric1 puncta1 #h-aj 787 in #aj 2 stri delicate1 #be-cj in #aj 4 ,l4 to #djj 4 ,the keel puncta are quite obscure4 ,nitzschia curvula ,wm4 ,sm4 ,nitzschia sigma var4 curvula 7,wm4 ,sm47 ,de ,toni4 ,fresh water4 ,hammonton ,pond2 ,may's ,landing1 ,n4 ,j4 ,pl4 #cc1 ,figs4 #d and #e4 ,gregory remarks that the keel puncta are seen in some specimens4 ,in both of the forms figured ,i have counted #cj stri in #aj 1 but1 after many examinations1 ,i have not been quite certain about the keel puncta4 ,the general appearance of the valves in any position is that of a ,stenopterobia or ,surirella anceps1 with which it occurs4 ,,nitzschia ,,clausii ,,hantzsch ,valve linear1 slightly sigmoid1 tapering to the sub-capitate ends2 keel puncta1 #aa in #aj 2 stri subtle4 ,l4 #dj 4 ,abundant in ,ridley ,creek1 ,delaware ,co4 7,palmer74 ,pl4 #cb1 ,fig4 #bj4 ,,obtus ,,nitzschia ,,obtusa ,,wm4 ,,sm4 ,frustule sigmoid1 rounded at the ends2 keel somewhat excentric1 inflexed in the middle1 the two median puncta distant2 keel puncta1 #e-f in #aj 2 stri1 #bf in #aj 4 ,l4 to #cjj 4 ,along the coast4 ,pl4 #ci1 ,fig4 #af4 ,,nitzschia ,,obtusa ,,var4 ,,flexella ,h4 ,l4 ,,smith ,valve more attenuate at the ends than the type and smaller4 ,pl4 #ci1 ,fig4 #ad4 ,,nitzschia ,,obtusa ,,var4 ,,scalpelliformis ,,grun4 ,valve linear1 with apices unilaterally truncate2 keel excentric2 keel puncta1 #h in #aj 2 stri1 #bf in #aj 4 ,l4 #dh 4 ,along the coast4 ,pl4 #cb1 ,fig4 #ag4 #abb,,spectabiles ,,nitzschia ,,spectabilis ,,var4 ,,americana ,,grun4 ,frustule linear1 slightly constricted in the middle1 with sub-cuneate ends2 valve linear1 slightly arcuate1 tapering to the sub-rostrate ends2 keel excentric1 keel puncta sometimes confluent1 #d-f in #aj 1 prolonged into short cost2 stri distinct1 #ad in the middle1 #ah at the ends in #aj 7but variable in different specimens74 ,l4 #ahf 4 ,blue clay1 especially at ,tioga ,st4 ,pl4 #cc1 ,fig4 #c2 ,pl4 #ci1 ,fig4 #a4 ,this is1 probably1 one of the most beautiful of the ,nitzschi4 ,it sometimes1 according to ,de ,toni1 reaches a length of #ebj 4 ,grunow states that his variety is found in the ,s4 ,bridgeton deposit4 ,in a slide of ,moeller labelled ,bridgeton1 ,maine1 ,i find specimens identical in every respect with the ,philadelphia form4 ,,lineares ,,nitzschia ,,linearis 7,,ag47 ,,wm4 ,,sm4 ,valve linear1 slightly inflexed in the middle2 keel excentric2 keel puncta1 #h-i in #aj 1 the two median distant2 stri about #cj in #aj 4 ,frustules in zone view narrowed toward the ends1 truncate4 ,l4 #ge 4 ,very common in fresh water4 ,pl4 #cb1 ,fig4 #ah4 ,fig4 #bj1 ,pl4 #dj1 a transverse section of frustule4 ,,lanceolat ,,nitzschia ,,palea 7,,kuetz47 ,,wm4 ,,sm4 ,valve linear-lanceolate1 slightly rostrate at the apices2 keel puncta1 #aj in #aj 1 the median not distant2 stri1 #cc-cf in #aj 2 zone view linear1 with rounded ends4 ,l4 #be-fe 4 ,fresh water4 ,pl4 #cb1 ,fig4 #ae4 ,,nitzschia ,,amphibia ,,grun4 ,valve lanceolate1 apices sometimes slightly produced1 rounded2 keel puncta1 #h-i in #aj 2 stri1 #af in #aj 4 ,l4 #bj-cb 4 ,fresh water4 ,pl4 #cb1 ,figs4 #ad and #be4 ,,nitzschia ,,communis ,,rab4 ,frustule linear1 slightly attenuated at the obtuse ends2 valve elliptical-lanceolate1 attenuated toward the obtuse ends2 keel puncta1 #ab in #aj 2 stri more than #cj in #aj 4 ,l4 #ce 4 ,fresh water4 ,pl4 #cb1 ,fig4 #ai4 ,,nitzschia ,,intermedia ,,hantzsch ,valve linear-lanceolate2 keel puncta1 #h in #aj 2 stri about #bd in #aj 4 ,l4 #ajj 4 ,crum ,creek4 ,not common4 ,pl4 #cc1 ,fig4 #b4 #abc,,nitzschiella ,,nitzschia ,,longissima 7,,br,b47 ,,ralfs ,valve linear-lanceolate1 with exceedingly long horns or beaks2 keel puncta about #aj in #aj 2 stri about #af in #aj 4 ,l4 to #ejj 4 ,shark ,river1 ,n4 ,j4 ,pl4 #cc1 ,fig4 #a4 ,forma parva ,v4 ,h4--,keel puncta1 #aj-ab in #aj 4 ,l4 #gj 4 ,east ,park ,reservoir1 ,philadelphia4 ,pl4 #cc1 ,fig4 #aj4 ,differs from ,n4 closterium 7,ehr47 ,wm4 ,sm4 in the keel puncta4 ,the type form occurs in brackish and salt water4 ,the occurrence of the variety in fresh water is another instance of the finding of presumably brackish forms in the water supply of the city4 ,if these cases prove to be unusual1 it may be because of one of two reasons4 ,the ,schuylkill ,river1 before the building of the dam at ,fairmount1 was tidal as far as the ,falls of ,schuylkill1 and brackish influences1 while not now existent1 may have caused the growth of forms which now survive4 ,another reason may be that the opening of the locks at ,fairmount ,dam may cause a slight admission of brackish forms from tidal water below4 ,the abundance of the brackish species appears to indicate that the first reason is the more plausible4 ,,nitzschia ,,reversa ,,wm4 ,,sm4 ,valve lanceolate extended into beaks or horns curving in opposite directions2 keel puncta not evident2 stri1 #bj-bf in #aj 4 ,l4 #gj 4 ,brackish water4 ,abundant in ,duck ,creek1 ,delaware ,river4 ,pl4 #cc1 ,fig4 #aa4 ,,nitzschia ,,acicularis 7,,kuetz47 ,,wm4 ,,sm4 ,valve lanceolate1 with beaks or horns about half the length of the median part of the valve2 keel puncta1 #ah in #aj 2 stri exceedingly delicate1 about #dj in #aj 4 ,l4 #de 4 ,fresh water4 ,darby ,creek4 ,pl4 #cc1 ,fig4 #ab4 ,,homoeocladia ,,ag4 7#ahbg7 7homoios1 like1 and clados1 a branch7 ,frustules like ,nitzschia1 but enclosed in branching or simple tubes4 ,,homoeocladia ,,filiformis ,,wm4 ,,sm4 ,frustule linear1 tumid in the middle1 obtuse at the ends2 valve linear-lanceolate1 with somewhat acute apices2 keel central or nearly so2 keel puncta1 #h in #aj 2 stri delicate4 ,l4 #ajh 4 ,fresh and brackish water4 ,newark1 ,n4 ,j4 ,pl4 #cc1 ,fig4 #ae4 #abd,,surirella ,,turpin 7#ahbh7 7named after ,dr4 ,suriray1 a physician of ,havre7 ,valve linear1 elliptical or ovate2 pseudoraphe linear or lanceolate2 a marginal keel forming wings or al seen in zone view2 cost short or reaching the pseudoraphe1 frequently with intercostal stri more or less evident4 ,the genus is divided by ,grunow according to the length and form of the cost4 ,i include ,stenopterobia4 ,section #a4--;,cost of nearly equal width throughout1 reaching the pseudoraphe4 ,section #b4--;,cost short or marginal4 ,section #c4--;,cost dilated at the margin1 attenuated toward the pseudoraphe4 ,section #d4--,valve having the appearance of ,nitzschia1 with inconspicuous al 7,stenopterobia74 ,the endochrome consists of two laminate chromatophores1 one on each valve4 ,the auxospores are single1 originating from the union of two frustules 7,h4 ,l4 ,smith74 ,,section #a ,,surirella ,,biseriata 7,,ehr47 ,,br,b4 ,valve lanceolate1 subacute at the ends2 cost robust1 about #b in #aj 1 parallel in the middle1 radiate at the ends2 pseudoraphe narrow4 ,l4 #ajj 4 ,surirella bifrons ,ehr4 ,fresh water4 ,pl4 #ci1 ,fig4 #ab2 ,pl4 #ce1 ,fig4 #b 7smaller form74 ,,surirella ,,linearis ,,wm4 ,,sm4 ,valve linear1 with cuneate ends1 slightly constricted in the middle2 cost parallel1 #b-c in #aj 4 ,l4 #ij 4 ,fresh water4 ,pl4 #ce1 ,fig4 #h4 ,,surirella ,,amphioxys ,,wm4 ,,sm4 ,valve oblong-linear1 with cuneate ends2 pseudoraphe narrow2 cost1 #c-d in #aj 2 stri1 #ad-af in #aj 1 somewhat radiate4 ,l4 #cd-ed 4 ,surirella moelleriana ,grun4 ,fresh and brackish water4 ,common along the coast4 ,pl4 #ce1 ,figs4 #ab and #ac4 ,,surirella ,,robusta ,,ehr4 ,valve linear-ovate2 pseudoraphe wide2 al prominent2 cost wide1 #a in #aj 4 ,frustule in zone view clavate4 ,l4 #bjj-cfe 4 ,fresh water4 ,pl4 #cf1 ,fig4 #b4 #abe,,surirella ,,splendida 7,,ehr47 ,,kuetz4 ,valve ovate2 cost1 #a to #b in #aj 2 pseudoraphe linear1 narrow4 ,l4 #abe-bjj 4 ,fresh water4 ,pl4 #ce1 ,fig4 #c4 ,s4 splendida is smaller than ,s4 robusta and wider in proportion1 but1 as intermediate forms occur1 it is difficult to distinguish between them4 ,,surirella ,,elegans ,,ehr4 ,valve ovate1 rounded at one end and acute at the other2 pseudoraphe lanceolate1 narrow2 cost1 #a in #aj 2 stri subtle1 #bb in #aj 4 ,frustule in zone view cuneate4 ,l4 #ahj-bbj 4 ,fresh water4 ,pl4 #cf1 ,fig4 #a4 ,,surirella ,,striatula ,,turpin ,valve broad1 obovate or elliptical1 rounded at each end2 cost1 #a in #aj 1 curved at the ends2 stri1 #ad in #aj 4 ,frustule in zone view cuneate2 marginal al quite robust4 ,l4 #ajj-afj 4 ,blue clay4 ,brackish water4 ,pl4 #cd1 ,fig4 #a4 ,in the specimen figured1 the outline is exactly elliptical1 although the species is usually conical at one end4 ,,surirella ,,gemma ,,ehr4 ,valve ovate or ovate-elliptical1 rounded at each end1 sometimes asymmetrical along the longitudinal axis2 pseudoraphe very narrow2 cost distant1 at irregular intervals1 about #b in #aj 1 somewhat radiate1 reaching the pseudoraphe2 stri1 #bj in #aj 1 punctate4 ,frustule in zone view cuneate4 ,l4 #gj-abj 4 ,along the coast4 ,pl4 #cf1 ,fig4 #d4 ,,surirella ,,tenera ,,greg4 ,valve ovate2 pseudoraphe narrow1 well-defined2 cost indistinct1 #b in #aj 1 their margins invisible2 stri about #ad in #aj 1 punctate1 more evident near the margin4 ,l4 #ij 4 ,surirella diaphana ,bleisch4 ,pavonia1 ,n4 ,j41 artesian well4 ,pl4 #ce1 ,fig4 #f4 ,the figure is that of the var4 nervosa ,a4 ,s4 7,atlas1 ,pl4 #bc1 ,fig4 #ae71 which differs from the type in having the position of the cost indicated by scattered puncta4 #abf,,section #b ,,surirella ,,guatimalensis ,,ehr4 ,valve ovate2 pseudoraphe very narrow and indistinct2 cost short1 marginal1 #b-b in #aj 1 absent from the rounded end4 ,l4 #abj 4 ,surirella cardinalis ,kitton4 ,smith's ,island1 ,delaware ,river4 ,pl4 #cf1 ,fig4 #e4 ,,surirella ,,ovalis ,,br,b4 ,valve ovate2 cost short1 marginal1 radiate1 #c-f in #aj 1 often unequal2 central area ovate1 indistinctly costate2 stri scarcely visible1 about #ah in #aj 2 pseudoraphe narrow4 ,l4 #de-ic 4 ,surirella davidsonii ,a4 ,s4 ,fresh or brackish water4 ,pl4 #ce1 ,fig4 #e2 ,pl4 #ci1 ,fig4 #aa4 ,the smaller specimen is from the ,delaware ,river1 and the larger from the ,hudson ,river4 ,,surirella ,,crumena ,,br,b4 ,valve nearly orbicular2 cost short1 marginal1 radiate2 pseudoraphe narrow1 indistinct2 central area indistinctly costate1 sometimes interrupted4 ,on account of the extreme confusion in the names of many forms which appear to be variations of ,s4 ovalis1 ,i have followed ,van ,heurck in retaining the original names as specific4 ,de ,toni gives ,s4 crumena as a variety of ,s4 ovalis4 ,fresh and brackish water4 ,quite common in the ,delaware ,river4 ,pl4 #ce1 ,fig4 #d4 ,,surirella ,,pinnata ,,wm4 ,,sm4 ,valve ovate or oblong-ovate2 cost reaching the linear pseudoraphe1 about #f in #aj 4 ,l4 #dj 4 ,surirella ovalis var4 pinnata 7,wm4 ,sm47 ,de ,toni4 ,s4 pinnata is the type of a number of small forms usually found together1 including ,s4 panduriformis1 ,s4 angusta and ,s4 minuta4 ,fresh water4 ,media 7,palmer74 ,pl4 #cf1 ,fig4 #g2 ,fig4 #i 7abnormal74 ,var4 minuta1 a small form of ,s4 pinnata1 occurs with the type4 ,,surirella ,,panduriformis ,,wm4 ,,sm4 ,valve linear-oblong1 with rounded ends1 more or less constricted in the middle2 otherwise as in ,s4 pinnata4 ,l4 #ed 4 ,fresh water4 ,pl4 #cf1 ,fig4 #f4 #abg,,surirella ,,angusta ,,kuetz4 ,valve linear1 with cuneate ends2 otherwise as in ,s4 pinnata4 ,fresh water4 ,pl4 #cf1 ,fig4 #h4 ,s4 pinnata1 ,s4 panduriformis1 and ,s4 angusta have a narrow central area1 and differ from ,s4 ovalis which has short cost4 ,,surirella ,,oblonga ,,ehr4 8 ,valve elliptical-lanceolate1 with obtuse ends2 cost1 marginal1 #b in #aj 2 median area granulate2 pseudoraphe narrow1 lanceolate1 scarcely visible2 stri about #ah in #aj 4 ,l4 #fj 4 ,blue clay4 ,rare4 ,pl4 #ce1 ,fig4 #i4 ,this has the outline and appearance of ,s4 oblonga ,ehr4 7,mik4 ,pl4 #ae1 ,fig4 #dh71 but the cost are closer4 ,,surirella ,,recedens ,a4 ,s4 ,valve ovate2 cost1 #b-b in #aj 2 pseudoraphe narrow1 not reaching the ends of the valve2 intercostal spaces more evident near the middle4 ,l4 #ej 4 ,blue clay4 ,not uncommon4 ,pl4 #ce1 ,fig4 #g4 ,,surirella ,,cruciata ,a4 ,s4 ,valve ovate2 pseudoraphe very narrow2 cost1 #b in #aj 2 the outline of several of the median cost strongly emphasized1 while the other cost are indistinct4 ,l4 #ed 4 ,blue clay4 ,pl4 #ce1 ,fig4 #aj4 ,,surirella ,,gracilis ,,grun4 ,valve linear1 with sub-cuneate ends1 slightly constricted in the middle2 pseudoraphe very narrow2 cost1 #f-g in #aj 2 transverse stri about #bf in #aj 1 punctate4 ,l4 #ge 4 ,according to ,de ,toni 7p4 #eih71 this form is a ,nitzschia4 ,it has1 however1 a narrow pseudoraphe4 ,pavonia1 ,n4 ,j41 artesian well4 ,rare4 ,pl4 #ce1 ,fig4 #aa4 ,,section #c ,,surirella ,,fastuosa ,,ehr4 ,valve ovate2 cost about #a-b in #aj 1 dilated at the margin and contracting at about one-fourth the distance toward the middle2 area1 ovate-lanceolate2 pseudoraphe1 narrow and indistinct2 intercostate stri more evident near the margin1 #ai in #aj 1 becoming again evident in a narrow band about one-half the distance to the pseudoraphe4 ,l4 #ej-abj 4 ,along the coast4 ,more common southward4 ,pl4 #ce1 ,fig4 #a4 #abh,,surirella ,,febigerii ,,lewis ,valve ovate-lanceolate2 cost about #b in #aj with punctate interspaces extending half the distance toward the median hyaline area1 which is divided longitudinally on each side of the narrow pseudoraphe by two longitudinal bands composed of short1 transverse1 irregular1 punctate lines4 ,along the coast4 ,pl4 #cf1 ,fig4 #c4 ,,section #d 7,,stenopterobia7 ,,surirella ,,anceps ,,lewis ,frustule linear1 straight or nearly so2 valve sigmoid with rounded apices2 cost marginal1 nearly obsolete2 stri distinct1 about #ae in #aj 2 pseudoraphe wide4 ,l4 to #cbj 4 ,hammonton ,pond and ,tom's ,river1 ,n4 ,j4 ,pl4 #cd1 ,fig4 #b4 ,,surirella ,,intermedia ,,lewis ,frustule linear1 straight1 widened at the truncate ends2 valve linear1 sigmoid1 tapering to the sub-acute ends2 cost about #e in #aj 2 stri about #bj in #aj 4 ,l4 variable4 ,hammonton ,pond1 ,n4 ,j4 ,pl4 #cd1 ,fig4 #c2 ,pl4 #ci1 ,fig4 #i 7zone view74 ,this1 perhaps1 is forma sub-acuta ,fricke4 ,fig4 #g1 ,pl4 #cd1 is probably a small form of ,s4 intermedia1 from ,willistown1 ,pa4 ,it resembles a ,nitzschia4 ,,surirella ,,delicatissima ,,lewis ,frustule linear1 rounded at the ends2 valve linear-lanceolate1 sometimes very slightly constricted in the middle1 with acute apices2 cost1 #e in #aj 2 stri about #bj in #aj 2 pseudoraphe well defined1 lanceolate4 ,l4 to #ij 4 ,fresh water4 ,newtown ,square4 ,pl4 #cd1 ,figs4 #e and #f 7small forms74 ,,surirella ,,arctissima ,a4 ,s4 ,valve linear1 tapering to the sub-acute ends2 cost marginal1 #e in #aj 2 stri1 #ah in #aj 2 pseudoraphe not evident4 ,l4 #ahd 4 ,may's ,landing1 ,n4 ,j4 ,pl4 #cd1 ,fig4 #d4 ,fig4 #aj1 ,pl4 #ci1 is a small form from ,newtown ,square1 ,pa41 in which the length is #hf 1 the cost #e and the stri #af in #aj 4 ,,podocystis ,,kuetz4 7#ahdd7 7pous1 a foot1 and cystis1 a bag7 ,frustules cuneate1 similar to ,surirella1 but attached by short stipes to other alg2 valve obovate4 #abi,,podocystis ,,adriatica ,,kuetz4 ,valve nearly symmetrical1 obovate1 with transverse cost about #d in #aj 1 alternating with double rows of coarse puncta2 median line distinct1 linear4 ,l4 #dc 4 ,podocystis americana ,bail4 ,hell ,gate1 ,n4 ,y4 ,pl4 #dj1 ,fig4 #f4 ,,cymatopleura ,,wm4 ,,sm4 7#ahea7 7cuma1 a wave1 and pleura1 a side7 ,valve elliptical2 surface transversely undulate1 with short1 marginal cost4 ,frustule in zone view linear1 with undulated sides4 ,auxospore formation as in ,surirella4 ,,cymatopleura ,,solea 7,,br,b47 ,,wm4 ,,sm4 ,valve oblong1 with cuneate apices1 constricted in the middle2 cost about #f in #aj 2 stri1 #aj in #aj 2 pseudoraphe scarcely visible4 ,l4 #ej-cjj 4 ,blue clay4 ,common in the ,hudson ,river4 ,pl4 #cd1 ,figs4 #h and #i4 ,,cymatopleura ,,elliptica 7,,br,b47 ,,wm4 ,,sm4 ,valve elliptical2 marginal cost short1 #c in #aj 2 stri delicate1 #ah in #aj 2 undulations four or more4 ,l4 #gj-adj 4 ,blue clay4 ,pl4 #cg1 ,fig4 #a4 ,forma spiralis4--,valve ovate1 swelled into curved ridges at the lower end1 with a contraction of the valve4 ,port ,penn1 ,delaware ,river4 ,pl4 #cg1 ,fig4 #b4 ,,cymatopleura ,,marina ,,lewis ,frustule linear1 with numerous undulations1 ends apiculate2 valve linear-lanceolate1 with acute ends2 stri transverse1 punctate at unequal intervals1 from #af-ah in #aj 4 ,l4 #dc 4 ,east ,river1 ,n4 ,y4 ,pl4 #cg1 ,figs4 #c and #d4 ,lewis states that the ends are more or less truncate4 ,i do not find them so4 ,,campylodiscus ,,ehr4 7#ahda7 7campulos1 curved like a saddle7 ,valve orbicular or sub-orbicular1 with cost or punctate rays converging from the circumference toward the hyaline centre1 which sometimes appears like a pseudoraphe4 ,frustule of two saddle-shaped valves at right angles to each other4 ,the zone view may be of almost any shape according to position4 ,endochrome consists of two bands1 each lining the inner surface of each valve4 ,auxospore and conjugation unknown4 #acj;,,campylodiscus ,,echeneis ,,ehr4 ,valve sub-orbicular1 saddle-shaped2 cost indistinct1 short1 marginal2 rows of round or elongated puncta converge toward the lanceolate1 hyaline median space4 ,diam4 #hj-adj 4 ,campylodiscus argus ,bail4 ,blue clay4 ,reservoir at ,thompson and ,twenty-sixth ,sts41 ,phila4 ,pl4 #cg1 ,fig4 #f4 ,this form1 usually considered as brackish and marine1 is occasionally found in fresh water4 ,according to ,deby1 it is fossil in the ,champlain deposit of ,n4 ,a4 ,,campylodiscus ,,hibernicus ,,ehr4 ,valve irregularly orbicular2 cost1 #dj-fj1 about #b in #aj 1 wide at the margin and attenuated toward the centre which is somewhat quadrate2 the radials rough with minute apiculi4 ,pensauken1 ,n4 ,j41 artesian well4 ,pl4 #cg1 ,fig4 #e4 #aca;,,appendix ,,collection ,,and ,,preparation ,,of ,,diatoms ,it is assumed that every student of the ,diatomace has a general knowledge of the collection1 preparation1 mounting and examination of material4 ,for the novice1 however1 the following methods1 used by the author for many years1 may be of service4 ,collection of ,fresh-water ,material4--,the yellow film on the inside of aquaria always contains small species4 ,stems of water-plants near the shores of ponds and the submerged roots1 the brownish coating of rocks in streams and water-falls1 fountains1 and water-troughs1 are prolific4 ,at all times of the year1 some diatoms may be found in a thin layer upon the mud of rivers or creeks4 ,in the spring1 brown patches of mud1 filled with bubbles1 floating near the shore in ponds1 or coming down with the current in rivers1 are rich in various forms4 ,within the limits assigned to our district1 ,i have made collections in the following localities3 ,schuylkill ,river1 including the region near ,fairmount ,dam1 several reservoirs and the water-supply2 the ,wissahickon and ,fairmount ,park1 ,darby1 ,crum and ,ridley ,creeks1 the ,neshaminy and the ,brandywine2 meadow pools and rivulets near the city2 the upper ,delaware1 the ,water ,gap and numerous cascades northward2 the ,shawangunk ,mountains and the ,poconos2 many parts of ,new ,jersey along the coast2 the ,pine ,barren region1 the ,hammonton1 ,atsion and ,kirkwood ,ponds and the swamps near ,atco4 ,in the collection of fresh-water material1 it is well to be provided with a number of small bottles4 ,take a handful of the water-plants or alg1 and squeeze the material into the bottles1 or1 lacking a bottle1 wrap it in paper4 ,with a small forceps it is possible to detach minute quantities of a pure gathering which may not need further preparation beyond burning to a red heat on the cover-glass before mounting4 ,a malacca cane1 with extending rod to which may be screwed a bottle1 net1 spoon or hook1 is useful on a long trip4 ,if it is impossible to separate the thin film of diatoms from the mud in the bed of streams1 dip up the surface mud with one bottle1 allow to settle a few minutes1 then pour off the supernatant liquid1 which will be comparatively free from sand1 into another bottle4 ,it must be confessed1 however1 that the mud in streams near ,philadelphia contains a large quantity of fine mica which1 in some instances1 it is impossible to remove4 ,collection of ,marine ,material4--,shell scrapings1 the stomachs of fish1 marine alg1 especially the brown and red alg1 the hulls of vessels1 mud from anchors and dredgings1 are all sources which may prove valuable4 ,in the sand ripples1 after the tide recedes1 a yellowish-brown deposit will be noticed4 ,this should be taken up carefully with a spoon and placed in a bottle2 the sand will settle at once and a very pure gathering will be held in suspension in the water4 ,such collections may be made along the entire coast of ,new ,jersey on sunny days in summer4 ,in salt meadows near ,absecon and ,hackensack1 large quantities of diatoms1 including ,pleurosigma1 may be obtained in the yellow scum floating on the surface4 ,the ,blue ,clay ,deposit4--,the blue clay occurs as a pre- or post-glacial deposit in the bed of the ancient ,delaware ,river1 and1 at depths varying usually from fifteen to forty feet below the surface1 has been obtained from artesian wells at ,pavonia1 ,pensauken and ,gloucester1 ,n4 ,j41 also at ,port ,penn on the ,delaware1 and especially from the dredgings #acbmade by the removal of ,smith's ,island opposite the city4 ,in the city proper1 it may be stated briefly that material may be found in a stratum of very light blue clay at a depth varying from twenty to sixty feet in many places south of ,arch ,st4 east of ,broad ,st41 and also along the beds of ancient rivulets near ,tioga ,st41 at ,sixteenth ,st41 and in certain other places which were probably subject to tidal overflow4 ,one of the best collections was made along the bank of the ,schuylkill at the east end of ,walnut ,st4 ,bridge1 at a depth of thirteen feet below the surface4 ,excavations for the ,reading ,terminal and the ,subway and several buildings1 as the ,bingham ,house1 have furnished numerous specimens4 ,cleaning the ,material4--,some gatherings may be so pure as to be ready for mounting when treated with dilute alcohol and oil of cloves4 ,if1 when gathered1 the diatoms are immersed in a saturated solution of picric acid for several days1 they may be stained with carmine or methylene blue1 or whatever may be required to emphasize the contents of the frustules1 including the endochrome and the pyrenoids4 ,after staining1 pass as rapidly as expedient through the treatment with dilute alcohol and oil of cloves1 and mount in benzol balsam1 avoiding heat4 ,a hot solution of mercuric bichloride is sometimes used for the preservation of the endochrome1 although washing is needed before mounting4 ,for the particular stain considered best for certain details of structure1 it will be advisable to consult works on ,micro-,chemistry or ,heinzerling 7l4 c474 ,the stains of most importance are carmine1 methylene blue1 hmatoxylin1 gold chloride and ,bismarck brown4 ,whatever method may be used in staining1 the identification of forms is impossible1 in most cases1 unless the valves are carefully cleaned and the cell-contents destroyed4 ,for this purpose provide a casserole holding from five to eight ounces1 an iron tripod stand with alcohol lamp1 several six-inch test-tubes1 preferably those with a standard base1 fitted with pure rubber corks4 ,take the material as free from twigs1 dead leaves1 sand1 and other matter as possible1 place it in the casserole1 and add about the same quantity of nitric acid4 ,boil for twenty minutes and then add about half a teaspoonful of powdered bichromate of potash1 stirring with a glass rod4 ,then take a beaker-glass partly filled with water and pour into it slowly the liquid which has been allowed to cool a short time1 whirling the casserole to cause the concentration of sand in the centre4 ,allow the material to settle for half an hour or longer1 according to the amount of diatoms and their size4 ,pour off the water1 add more water1 and place in a test-tube4 ,repeat the decantation1 shaking the test-tube1 closed with a rubber cork1 vigorously each time4 ,from time to time whirl the diatoms in the casserole and throw away the sand collected in the centre4 ,by repeating the decantation1 shaking and whirling1 the deposit will be found to consist almost entirely of diatoms4 ,it may be necessary to repeat the boiling in the acid and bichromate4 ,if1 however1 any detritus other than sand is noted1 boil in sulphuric acid and add from time to time minute pinches of powdered chlorate of potash1 being careful to protect the eyes by holding a piece of glass before them2 otherwise the explosions which occur are likely to throw some of the boiling acid into the eyes and destroy the sight4 ,the material1 when clean1 should be white or1 in the case of ,synedra1 yellowish4 ,it is quite easy to construct a box fitted with the proper apparatus for boiling and provided with a glass door for observation1 and a method of introducing the chlorate of potash through a small aperture or tube4 ,the box may be placed in the garden or fastened outside of a window so that the poisonous fumes may be carried off4 ,an excellent method1 in the case of larger forms1 is to boil the material already cleaned by the acid in water to which a few shavings of coarse brown soap are added4 ,the difference in density will hold in suspension any flocculent matter1 and while many of the smaller #acc;forms will not settle1 the others will be perfectly cleaned4 ,when satisfied with the cleaning1 preserve the stock material in part alcohol and1 in using1 pour into a smaller bottle the amount required1 replace the dilute alcohol with distilled water1 and mount as directed4 ,it often happens that gatherings are made consisting almost entirely of sand4 ,attempts at cleaning in the usual way will cause the loss of nearly all of the diatoms4 ,in this case1 after the material has been treated with acid until nothing remains but sand and a few diatoms1 the mechanical finger must be used4 ,in the cleaning of marine deposits1 various methods may be required4 ,in the case of partly siliceous species1 washing in pure water repeatedly is all that can be done4 ,the larger and heavier diatoms may be separated from the sand by elutriation or by whirling in a casserole1 by rocking in a shallow dish the shape of a watch crystal1 or by pouring slowly over a strip of plate-glass at least two feet in length inclined at an angle of thirty degrees4 ,the sand will cling to the glass1 while the greater portion of the diatoms will run off4 ,where particles of shells or foraminifera are present1 a preliminary boiling in hydrochloric acid is advisable4 ,in all marine gatherings1 the salt should first be washed out before proceeding with the cleaning4 ,for hardened masses of clay and for fossil deposits1 it is necessary to boil in carbonate of soda and follow with the acid treatment4 ,citric acid and acetate of potash used alternately in boiling may be tried4 ,soaking for a time in acetate of potash and allowing the material to deliquesce for a week before further process1 has proved successful in some instances4 ,the repetition of several methods and the gentle breaking of the harder masses with the point of a needle will disintegrate almost any diatomaceous earth1 but1 as a last resort for refractory deposits1 boil in pure water1 add a piece of caustic potash about the size of a pea1 continue the boiling not more than thirty seconds longer1 and pour instantly into dilute hydrochloric acid2 otherwise the diatoms will be destroyed4 ,afterwards proceed with the usual treatment4 ,slides and ,covers4--,take half an ounce of ,no4 #a covers1 circles1 and place them in a wide-mouthed bottle4 ,add a portion of the following mixture 7,dr4 ,carl ,seiler's formula73 ,bichromate of potash #b oz4 ,sulphuric acid #c fl4 oz4 ,water #be fl4 oz4 ,shake the bottle in order that the surfaces of the covers may be fully exposed to the action of the acid1 and set aside for several hours4 ,decant the solution1 add water repeatedly until all traces of the mixture are removed1 and keep the circles in the bottle in fifty-per cent4 alcohol4 ,when needed1 take out a circle with forceps and dry on a linen cloth4 ,the slides may be treated in the same way1 or they may be easily prepared by immersion in a solution of washing soda1 and then washed and dried4 ,this process may be used in cleaning the balsam or styrax from old slides4 ,preparation of ,strewn ,mounts4--,place several covers on the mounting stand4 ,with a dipping tube1 cover each circle with distilled water1 and add a small drop of the prepared diatoms1 being careful to avoid any vibration of the stand4 ,heat the stand until small bubbles begin to appear1 remove the lamp1 and allow the water to evaporate4 ,if the above method is carefully followed1 the diatoms will be deposited in an even layer1 provided the material is not too dense4 ,take a slide1 centre it1 and place a small amount of styrax on the centre4 ,invert the prepared cover1 and gently place it upon the styrax4 ,heat the slide #acdon the mounting stand until the styrax bubbles and then allow to cool4 ,if bubbles still remain1 heat again until they disappear4 ,it is well to mount several slides more than required1 as some may be imperfect4 ,preparation of ,selected ,mounts4--,take a slide1 place a minute quantity of beeswax on two places at a distance apart nearly equal to the diameter of the cover used4 ,place a cover on the wax and press it down flat1 or sufficiently to keep it in position4 ,dip a fine needle into the following cement3 ,glacial acetic acid #ab drachms ,gelatine #b drachms ,alcohol #a drachm ,this is made by adding the acid to the gelatine in a water-bath and then the alcohol1 and filtering4 ,apply the moistened needle to the centre of the cover and spread as small a quantity as possible in a thin layer4 ,now place the slide upon the turn table1 centre it with respect to the position of the gelatine1 and with the finest sable brush draw a circle about a tenth of an inch in diameter around the gelatine in water-color 7,windsor71 blue or vermilion1 or in ,india ink4 ,instead of the water-color1 a circle of tin-foil the size of the cover and pierced with a hole in the centre may be used1 but the colored circle is to be preferred1 as1 when brought into view1 it indicates exactly the focus required for observing the diatom4 ,the bottle containing the cleaned material1 which has been kept in water and alcohol1 should be refilled with distilled water and well shaken1 when a small portion may be taken up with a dipping tube and evenly distributed over a portion of a slide and then dried4 ,by the use of a mechanical finger1 fitted with a small piece of finely spun glass attached by wax to the holder of the finger1 when the microscope is focussed until the glass thread touches the diatom selected1 it will adhere to the thread4 ,raise the body of the microscope1 remove the slide containing the spread material1 or move it to another part of the stage1 and place the slide with the prepared cover in the same position4 ,now carefully lower the body-tube of the instrument until the diatom rests upon the gelatine1 breathe gently upon it1 remove the cover from the slide1 invert it over another slide containing a drop of styrax and proceed by heating to mount as before4 ,the size of the diatom1 the amount of gelatine1 and several other factors1 will enter into the question of success or failure4 ,i have1 however1 employed the above method and have mounted thousands of slides of selected diatoms successfully4 ,it is necessary to avoid any air current which will cause the diatom to fall from the thread4 ,on very cold days the glass thread sometimes becomes electrified and the diatoms will not stick2 on sultry days in ,august in our locality the diatoms will stick too closely4 ,by the same method1 slides of arranged diatoms can be made using a glass circle properly marked with lines in the eye-piece4 ,care should be taken to use glass threads more or less in proportion to the size of the diatoms4 ,a cat's whisker is preferred by some to the glass thread4 ,it has the advantage of not breaking1 but unless it is quite short it is too flexible4 ,if the point of the thread becomes covered with gelatine1 lower it into a minute drop of water upon a separate slide1 and by moving it about it will be cleaned4 ,the diatom itself may be washed in the same way1 if it is not too small4 ,instruments ,required4--,for collecting1 in order to determine the quality of the find1 any simple lens of fifteen to twenty diameters is sufficient4 ,a ,stanhope is quite useful #ace;although difficult to obtain1 while an achromatic triplet of sufficient power will probably be all that is necessary4 ,for selecting with the mechanical finger1 an objective of two-thirds-inch focus is the most convenient1 but for determining species a one-fifth-inch is needed1 an immersion objective being essential for minute forms4 ,no particular form of microscope is required4 ,any instrument having standard parts1 inclination of the body to the axis1 a sub-stage condenser and movable stage1 will prove serviceable in nearly all investigations4 ,for critical work1 measurement of stri and location of specimens on the slide1 the large models of ,bausch and ,lomb leave nothing to be desired4 ,one smaller instrument may be used for rapid examination and for selection with the mechanical finger4 ,if the stage is supplied with a vernier1 the diatoms can be located rapidly and recorded for future reference4 ,the ,zentmayer ,army ,hospital stand with mechanical stage is excellent4 ,the ,continental stands1 convenient for laboratory work1 especially in the examination of bacteria1 are not so serviceable as the larger stands of ,american and ,english make4 ,the stand especially designed by ,dr4 ,henri ,van ,heurck1 the celebrated ,belgian naturalist1 is1 without doubt1 admirably suited to the investigation of the ,diatomace4 ,in the form of the ,circuit ,stage as made by ,watson and ,sons1 of ,london1 supplied with proper condenser and mechanical stage with vernier attachment1 it has been used in the preparation of the present work with much satisfaction4 ,the drawings have all been made with an ,abb camera lucida1 a #c mm4 objective and a ,no4 #aj eye-piece1 producing a magnification of about #hjj diameters4 ,all illustrations are from actual specimens in my cabinet or1 in a few instances1 from slides sent me by friends4 ,in the measurement of stri and puncta1 the number in ten microns is stated1 and will be found to be approximately correct in most of the drawings1 except when the number is in excess of twenty in ten microns1 in which case it is impossible to represent the markings accurately on figures of the magnification adopted4 ,all drawings are from specimens in this locality1 except in a few cases mentioned in the text4 #acg;,,index 7,,synonyms ,,in ,,italics7 ,,page ,achnanthes1 #eh brevipes ,ag41 #ei coarctata 7,brb47 ,grun41 #ei danica 7,floegel7 ,grun41 #fj exigua ,grun41 #ei inflata 7,kuetz47 ,grun41 #ei lanceolata 7,brb47 ,grun41 #ei linearis forma curta ,h4,l4,s41 #ei longipes ,ag41 #eh subsessilis ,kuetz41 #ei ,actinella1 #ed punctata ,lewis1 #ed ,actinocyclus1 #bf barkleyi var4 aggregata ,rattr41 #bg ellipticus var4 delawarensis n4 var41 #bg moniliformis ,ralfs1 #bg ,actinoptychus1 #bd cellulosa ,ehr41 #bd heliopelta ,grun4 var481 #be omphalopelta ,ehr41 #bd undulatus 7,kuetz47 ,ralfs1 #bd vulgaris var4 interrupta n4 var41 #bd ,amphipleura1 #gh pellucida ,kuetz41 #gh rutilans 7,trentepohl7 ,cl41 #gh ,amphiprora1 #fh alata ,kuetz41 #fh conspicua ,grev41 #fh lepidoptera ,greg41 #fi ornata ,bail41 #fh paludosa ,wm4 ,sm41 #fh pulchra ,bail41 #fh ,amphitetras1 antediluviana ,ehr41 #cb tessellata ,shad41 #cb ,amphora1 #fe acuta ,greg41 #ff angusta var4 eulensteinii ,grun41 #fg aponina ,kuetz41 #ff arenaria ,donk41 #fg areolata ,grun41 #ff coffiformis 7,ag47 ,kuetz41 #ff crassa ,greg41 #fe eulensteinii ,a4,s41 #fg gigantea var4 fusca ,a4,s41 #fe insecta ,grun41 #fi lvis ,greg41 #ff lineolata ,ehr41 #ff mucronata ,h4,l4,s41 #fi obtusa ,greg41 #fg ocellata var4 cingulata ,cl41 #fg ostrearia ,brb41 #ff ovalis 7,brb47 ,kuetz41 #fe var4 libyca 7,ehr47 ,cl41 #fe var4 pediculus 7,kuetz47 ,cl41 #fe plicata ,greg41 #ff porcellus ,kitton1 #ff proteus ,greg41 #fe quadrata ,brb41 #ff robusta ,greg41 #fe salina ,wm4 ,sm41 #ff vitra ,cl41 #ff ,anomoeoneis1 #hj follis 7,ehr47 ,cl41 #hj serians ,brb41 #hj sphrophora 7,kuetz47 ,cl41 #hj ,anorthoneis1 #ef excentrica 7,donk47 ,grun41 #ef ,asterionella1 #ej formosa ,hass41 #ej inflata ,heib41 #ej ,attheya1 #ch decora ,west1 #ch ,aulacodiscus1 #bf argus 7,ehr47 ,a4,s41 #bf ,auliscus1 #bh clatus ,bail41 #bi pruinosus ,bail41 #bh punctatus ,bail41 #bh sculptus 7,wm4 ,sm47 ,ralfs1 #bi spinosus ,christian1 #bi ,auricula1 #fi insecta 7,grun47 ,cl41 #fi mucronata 7,h4,l4,s47 ,per41 #fi ,bacillaria1 #aai paradoxa ,gmelin1 #aai ,biddulphia1 #ca alternans 7,bail47 ,v4 ,h41 #cc antediluviana 7,ehr47 ,v4 ,h41 #cb biddulphiana 7,smith71 #ca favus 7,ehr47 ,v4 ,h41 #ca granulata ,roper1 #cb lvis ,ehr41 #cc pulchella ,gray41 #ca reticulum 7,ehr471 #cc rhombus 7,ehr47 ,wm4 ,sm41 #cb smithii 7,ralfs7 ,v4 ,h41 #cb turgida 7,ehr47 ,wm4 ,sm41 #cb ,brbissonia1 #gi boeckii 7,kuetz47 ,grun41 #gi palmerii n4 sp41 #hj ,caloneis1 #ha brevis var4 vexans ,grun41 #hb formosa 7,greg47 ,cl41 #hb liber 7,wm4 ,sm47 ,cl41 #ha permagna 7,bail47 ,cl41 #hb var4 lewisiana n4 var41 #hb powellii 7,lewis7 ,cl41 #hc silicula 7,ehr47 ,cl41 #ha var4 inflata 7,grun47 ,cl41 #ha trinodis 7,lewis71 #ha wardii ,cl41 #hb ,campylodiscus1 #abi argus ,bail41 #acj echeneis ,ehr41 #acj hibernicus ,ehr41 #acj ,cerataulus smithii ,ralfs1 #cb turgidus ,ehr41 #cb ,cocconeis1 #eg dirupta ,greg41 #eh pediculus ,ehr41 #eg pellucida ,grun41 #eh placentula ,ehr41 #eg var4 lineata 7,ehr47 ,v4 ,h41 #eh scutellum ,ehr41 #eg var4 ornata ,grun41 #eg ,cocconema asperum ,ehr41 #fa ,colletonema neglectum ,thwaites1 #ie vulgaris ,thwaites1 #gg ,conferva biddulphiana ,smith1 #ca flocculosa ,roth1 #cf moniliformis ,mueller1 #af nummuloides ,dillw41 #afag rutilans ,trentepohl1 #gh ,coscinodiscus1 #ba argus ,ehr41 #bc asteromphalus ,ehr41 #bc var4 omphalantha ,grun41 #bc biangulatus ,a4 ,s41 #bc denarius ,a4 ,s41 #bb excentricus ,ehr41 #ba var4 perpusilla ,grun41 #ba lewisianus ,grev41 #bd lineatus ,ehr41 #ba marginatus ,ehr41 #bb minor ,wm4 ,sm41 #ad nitidulus ,grun41 #ba nitidus ,greg41 #ba oculus-iridus ,ehr41 #bc polyacanthus ,grun41 #bb radiatus ,ehr41 #bc striatus ,kuetz41 #ai subaulacodiscoidalis ,rattr41 #bc subtilis ,ehr41 #ba velatus ,ehr41 #bb ,creswellia turris ,grev41 #ah ,cyclotella1 #ai antiqua ,wm4 ,sm41 #bj comta 7,ehr47 ,kuetz41 #bj dallasiana ,wm4 ,sm41 #ai kuetzingiana ,wm4 ,sm41 #ai meneghiniana ,kuetz41 #ai var4 stelligera ,cl4 and ,grun41 #bj var4 stellulifera ,cl4 and ,grun41 #bj operculata 7,ag47 ,kuetz41 #bj scotica ,kuetz41 #ah striata 7,kuetz47 ,grun41 #ai stylorum 7,br487 ,v4 ,h41 #bj ,cymatopleura1 #abi elliptica 7,brb47 ,wm4 ,sm41 #abi marina ,lewis1 #abi solea 7,brb47 ,wm4 ,sm41 #abi ,cymbella1 #fj affinis ,kuetz41 #fa amphicephala ,ngeli1 #fa aspera 7,ehr47 ,cl41 #fa cistula 7,hempr47 ,kirchn41 #fb cuspidata ,kuetz41 #fj cymbiformis 7,kuetz47 ,brb41 #fb ehrenbergii ,kuetz41 #fj excisa 7,kuetz47 ,de ,toni1 #fa gastroides ,kuetz41 #fa gracilis 7,rab47 ,cl41 #fd heteropleura 7,ehr47 ,kuetz41 #fj lacustris 7,ag47 ,cl41 #fd lanceolata 7,ehr47 ,kirchn41 #fb mexicana 7,ehr47 ,a4 ,s41 #fb naviculiformis ,auerswald1 #fj parva 7,wm4 ,sm47 ,cl41 #fa philadelphica n4 sp41 #fc prostrata 7,berk47 ,cl41 #fc rhomboidea n4 sp41 #fc sinuata ,greg41 #fa triangulum 7,ehr47 ,cl41 #fc tumida 7,brb47 ,v4 ,h41 #fb turgida 7,greg47 ,cl41 #fc var481 #fc ventricosa ,kuetz41 #fb ,diatoma1 #da anceps 7,ehr47 ,kirchn41 #db arcuatum ,lyng41 #ce biddulphianum ,ag41 #ca hiemale 7,lyng47 ,heib41 #db marinum ,lyng41 #cg vulgare ,bory41 #db var4 elongatum 7,ag471 #db var4 grande 7,wm4 ,sm47 ,grun41 #db ,dictyoneis1 #gh marginata var4 commutata ,cl41 #gi var4 maxima n4 var41 #gi var4 typica ,cl41 #gh ,dimerogramma1 #df marinum 7,greg47 ,ralfs1 #df minus 7,greg47 ,ralfs1 #dg sinuatum ,thwaites1 #aai surirella 7,ehr47 ,grun41 #df ,diploneis1 #hd campylodiscus 7,grun47 ,cl41 #hf crabro ,ehr4 var481 #he var4 expleta 7,a4 ,s47 ,cl41 #he var4 pandura 7,brb47 ,cl41 #he var4 pandurella ,cl481 #he elliptica 7,kuetz47 ,cl41 #hd var4 minutissima ,grun41 #he excentrica n4 sp41 #he fusca var4 delicata 7,a4 ,s47 ,cl41 #he gemmata 7,grev47 ,cl41 #hf gruendleri 7,a4 ,s47 ,cl41 #he oculata 7,brb47 ,cl41 #hf puella 7,schum47 ,cl41 #he smithii 7,brb47 ,cl41 #hd ,ditylum1 #cj intricatum 7,west7 ,grun41 #cj ,echinella circularis ,grev41 #dj flabellata ,carm41 #ci paradoxa ,lyng41 #ci ,encyonema1 #fb ,epithemia1 #aaa argus ,kuetz41 #aaa var481 #aaa gibba var4 ventricosa ,kuetz41 #aac gibberula var4 producta ,grun41 #aab marina ,donk41 #aad muelleri ,a4 ,s481 #aaa musculus ,kuetz41 #aab var4 constricta 7,brb47 ,v4 ,h41 #aab succincta ,brb41 #aab turgida 7,ehr47 ,kuetz41 #aaa zebra var4 proboscidea 7,kuetz47 ,grun41 #aab ,eunotia1 #ea bactriana ,ehr41 #ed biceps ,ehr41 #ec bidentula ,wm4 ,sm41 #ed bigibba ,greg41 #ec formica ,ehr4 var481 #ed gracilis 7,ehr47 ,rab41 #ea hemicyclus 7,ehr47 ,ralfs1 #ec incisa ,greg41 #eb luna ,ehr41 #eb lunaris 7,ehr47 ,grun41 #ec major 7,wm4 ,sm47 ,rab41 #ea nymanniana ,grun41 #ea pectinalis 7,kuetz471 #eb var4 solierolii 7,kuetz471 #eb var4 undulata ,ralfs1 #eb var4 ventricosa ,grun41 #eb prrupta ,ehr41 #ec var4 bidens ,grun41 #ec robusta ,ralfs1 #ec veneris ,kuetz41 #eb ,eunotogramma1 #cc lve ,grun41 #cc ,euodia1 #cd gibba ,bail41 #cd ,eupodiscus1 #bh argus 7,ehr47 ,wm4 ,sm41 #bf radiatus ,bail41 #bh radiatus ,wm4 ,sm41 #cb ,fragilaria1 #dd arctica ,grun41 #dd capucina var4 mesolepta ,rab41 #de construens 7,ehr47 ,grun41 #de harrisonii 7,wm4 ,sm47 ,grun41 #de linearis ,cstr41 #de parasitica 7,wm4 ,sm471 #de undata ,wm4 ,sm41 #dd virescens ,ralfs1 #dd ,frustulia1 #gg acuminata ,kuetz41 #gf interposita 7,lewis7 ,de ,toni1 #gh lewisiana 7,grev47 ,de ,toni1 #gg rhomboides 7,ehr47 ,de ,toni1 #gg var4 amphipleuroides ,grun41 #gg var4 saxonica ,rab41 #gg vulgaris 7,thwaites7 ,de ,toni1 #gg ,gaillonella1 #af crenulata ,ehr41 #ae granulata ,ehr41 #ae moniliformis ,bail41 #af nummuloides 7,dillw47 ,bory41 #af sulcata ,ehr41 #ae ,gloeonema1 #fc triangulum ,ehr41 #fc ,gomphoneis1 #gj herculaneum 7,ehr47 ,cl41 #gj mamilla 7,ehr47 ,cl41 #gj ,gomphonema1 #gj acuminatum1 #ga var4 coronata 7,ehr47 ,cl41 #ga var4 trigonocephala 7,ehr47 ,cl41 #ga var4 turris 7,ehr47 ,cl41 #ga var4 turris 7,ehr47 ,cl481 #ga quale ,greg41 #gb angustatum ,kuetz41 #gb augur ,ehr41 #gb brasiliense var4 demerar ,grun481 #gc capitatum ,ehr41 #gb capitatum var4 herculaneum ,ehr41 #gj constrictum ,ehr41 #gb geminatum ,lyng41 #ga insigne ,greg41 #ga intricatum ,kuetz41 #gb lanceolatum var4 insignis 7,greg47 ,cl41 #ga montanum ,schum41 #ga olivaceum ,lyng41 #gc parvulum var4 micropus 7,kuetz47 ,cl41 #gc sarcophagus ,greg41 #gb sphrophorum ,ehr41 #gb subclavatum var4 montana ,schum41 #ga tinctum ,ag41 #dj ventricosum ,greg41 #gc ,grammatophora1 #cf angulosa var4 hamulifera 7,kuetz47 ,grun41 #cg islandica ,ehr41 #cg marina 7,lyng47 ,kuetz41 #cg var4 subtilissima 7,bail47 ,v4 ,h41 #cg serpentina ,ralfs1 #cg subtilissima ,bail41 #cg ,gyrosigma1 #ge acuminatum 7,kuetz47 ,cl41 #gf attenuatum 7,kuetz47 ,cl41 #ge balticum 7,ehr47 ,cl41 #ge var4 similis 7,grun47 ,cl41 #gf fasciola 7,ehr47 ,cl41 #gg hippocampus 7,ehr471 #ge kuetzingii 7,grun47 ,cl41 #gf parkeri var4 stauroneioides ,grun41 #ge prolongatum 7,wm4 ,sm47 ,cl41 #gf scalproides 7,rab47 ,cl41 #gf simile 7,grun471 #gf spencerii var4 nodifera ,grun41 #gf strigilis 7,wm4 ,sm47 ,cl41 #gf ,hantzschia1 #aac amphioxys 7,ehr47 ,grun41 #aac var4 major ,grun41 #aad marina 7,donk47 ,grun41 #aad virgata 7,roper7 ,grun41 #aad ,himantidium pectinate ,kuetz41 #eb ,homoeocladia1 #abc filiformis ,wm4 ,sm41 #abc ,hyalodiscus1 #ag radiatus var4 arctica ,grun41 #ag scoticus 7,kuetz47 ,grun41 #ah stelliger ,bail41 #ag subtilis ,bail41 #ah ,licmophora1 #ch baileyi 7,ehr47 ,grun41 #dj ehrenbergii 7,kuetz47 ,grun41 #dj flabellata 7,carm47 ,ag41 #ci gracilis 7,ehr47 ,grun41 #ci var4 elongata 7,kuetz47 ,de ,toni1 #ci lyngbyei 7,kuetz47 ,grun41 #dj ovulum ,mer41 #ci paradoxa 7,lyng47 ,ag41 #ci splendida ,wm4 ,sm41 #ci tincta 7,ag47 ,grun41 #dj ,lysigonium1 #af moniliforme 7,muell47 ,link1 #af nummuloides 7,lyng47 ,o',meara1 #ag varians 7,ag47 ,de ,toni1 #ag ,mastogloia1 #hf angulata ,lewis1 #hg apiculata ,wm4 ,sm41 #hg braunii ,grun41 #hg elegans ,lewis1 #hg exigua ,lewis1 #hg kinsmanii ,lewis1 #hg lanceolata ,thwaites1 #hg smithii ,thwaites1 #hg ,meloseira1 #ad borreri ,grev41 #ag crenulata 7,ehr47 ,kuetz41 #ae distans 7,ehr47 ,kuetz41 #ad gowenii ,a4 ,s41 #ae granulata 7,ehr47 ,ralfs1 #ae nivalis ,wm4 ,sm41 #ad nummuloides ,ag41 #af roeseana ,rab41 #ae var4 epidendron 7,ehr47 ,grun41 #ae sulcata ,kuetz41 #ae undulata 7,ehr47 ,kuetz41 #ae varians ,ag41 #ag ,meridion1 #dj circulare 7,grev47 ,ag41 #dj constrictum ,ralfs1 #da ,micromega ramosissimum ,ag41 #ie ,navicula1 #hi affinis ,ehr41 #hc americana ,ehr41 #ih amphibola ,cl41 #ib amphigomphus ,ehr41 #hc anglica ,ralfs1 #if angulata ,quek41 #gd ardua ,mann1 #if arenaria ,donk41 #ie atomus ,ngeli1 #ajj bacillum ,ehr41 #ih baltica ,ehr41 #ge brasiliensis var4 bicuneata ,cl41 forma constricta1 #ib crucigera 7,wm4 ,sm47 ,cl41 #ajj cryptocephala ,kuetz41 #ig cuspidata ,kuetz41 #ajj var4 ambigua 7,ehr47 ,cl41 #ajj cyprinus 7,wm4 ,sm471 #ie delawarensis ,grun41 #ib dicephala ,wm4 ,sm41 #if digito-radiata var4 cyprinus 7,ehr487 ,wm4 ,sm41 #ie elegans ,wm4 ,sm41 #aja var4 cuspidata ,cl41 #aja firma ,kuetz41 #hd fischeri ,a4 ,s41 #ij follis ,ehr41 #hj fuchsii ,pant41 #ia gastrum ,ehr41 #if gigas ,a4 ,s41 #ajc globiceps ,lagerstedt1 #if gracilis var4 schizonemoides 7,ehr47 ,v4 ,h41 #ie grevillei 7,ag47 ,cl41 #ii hasta ,pant41 #ig var4 punctata n4 var41 #ig hennedyi ,wm4 ,sm41 #ic var4 circumsecta ,grun41 #ic var4 manta ,a4 ,s41 #ic hippocampus ,ehr41 #ge hitchcockii ,ehr41 #hd humerosa ,brb41 #ia var4 elongata ,pant41 #ia var4 fuchsii 7,pant47 ,cl41 #ia humilis ,donk41 #if hungarica var4 capitata 7,ehr47 ,cl41 #if inflexa ,greg41 #if integra ,wm4 ,sm41 #ii interposita ,lewis1 #gh iridis ,ehr41 #hd irrorata ,grev41 #ic lacustris ,greg41 #ib lanceolata var4 arenaria 7,donk47 ,cl41 #ie latissima ,greg41 #ij var4 elongata 7,pant47 ,cl41 #ia libellus ,greg41 #ii limosa ,donk41 #ha longa 7,greg47 ,ralfs1 #ig lyra ,ehr41 #ic var4 dilatata ,a4 ,s41 #ic var4 ehrenbergii ,cl41 #ic var481 #ic maculata 7,bail47 ,cl41 #ij marginata ,lewis1 #gh marina ,ralfs1 #ib minima ,grun41 #ih mormonorum ,grun41 #ajg mutica ,kuetz41 #ig oblonga ,kuetz41 #ig oculata ,brb41 #hf palpebralis ,brb41 #aja pennata ,a4 ,s41 #if peregrina ,ehr41 #id pinnata ,pant481 #if placenta ,ehr41 #id prtexta ,ehr41 #ib producta ,wm4 ,sm41 #hc punctata var4 asymmetrica ,lagerstedt1 #ib punctulata ,wm4 ,sm41 #ib pupula var4 bacillarioides ,grun41 #ih pusilla ,wm4 ,sm41 #ia var4 subcapitata n4 var41 #ia pygma ,kuetz41 #id radiosa ,kuetz41 #id ramosissima 7,ag47 ,cl41 #ie rectangulata ,greg41 #aaj reinhardtii ,grun41 #ie rhyncocephala ,kuetz41 #ig salinarum ,grun41 #ie semen ,ehr41 #ih silicula ,ehr41 #ha socialis ,palmer1 #ajd spectabilis var4 emarginata ,cl41 #id sphrophora ,kuetz41 #hj spicula 7,hickie7 ,cl41 #ajj trochus ,kuetz41 #hj tumida 7,brb47 ,cl41 #ii viridula var4 rostellata ,kuetz41 #ie yarrensis ,grun41 #aja ,neidium1 #hc affine 7,ehr47 ,pfitzer1 #hc var4 amphirhyncus 7,ehr47 ,cl41 #hc var4 genuina forma maxima ,cl41 #hc var4 genuina forma minor ,cl41 #hc amphigomphus 7,ehr47 ,pfitzer1 #hc hitchcockii 7,ehr47 ,cl41 #hd iridis 7,ehr47 ,cl41 #hd productum 7,wm4 ,sm47 ,cl41 #hc ,nitzschia1 #aad acicularis 7,kuetz47 ,wm4 ,sm41 #abc acuminata 7,wm4 ,sm47 ,grun41 #aag amphibis ,grun41 #abb amphioxys ,wm4 ,sm41 #aad apiculata 7,greg47 ,grun41 #aag bilobata ,wm4 ,sm41 #aah circumsuta 7,bail47 ,grun41 #aah clausii ,hantzsch1 #aba communis ,rab41 #abb compressa ,bail41 #aaf var4 minor ,h4 ,l4 ,s41 #aaf curvula ,wm4 ,sm41 #aba dissipata 7,kuetz47 ,grun41 #abj dubia ,wm4 ,sm41 #aah epithemioides ,grun41 #aah fluminensis ,grun41 #abj granulata ,grun41 #aaf insignis ,greg41 #aai intermedia ,hantzsch1 #abb linearis 7,ag47 ,wm4 ,sm41 #abb litoralis var4 delawarensis ,grun41 #aah longissima 7,brb47 ,ralfs1 #abc forma parva ,v4 ,h41 #abc macilenta ,greg41 #abj navicularis 7,brb47 ,grun41 #aaf obtusa ,wm4 ,sm41 #aba var4 flexella ,h4 ,l4 ,s41 #aba var4 scalpelliformis ,grun41 #aba palea 7,kuetz47 ,wm4 ,sm41 #abb panduriformis ,greg41 #aag var4 minor ,grun41 #aag paradoxa 7,gmelin7 ,grun41 #aai paxillifer 7,o4 ,f4 ,mueller7 ,heib41 #aai plana ,wm4 ,sm41 #aag punctata 7,wm4 ,sm47 ,grun41 #aaf reversa ,wm4 ,sm41 #abc scalaris 7,ehr47 ,wm4 ,sm41 #aai sigma 7,kuetz47 ,wm4 ,sm41 #aba var4 curvula 7,wm4 ,sm47 ,de ,toni1 #aba sigmatella ,greg41 #aba sinuata var4 tabellaria 7,grun47 ,v4 ,h41 #aai spathulata ,brb41 #abj spectabilis var4 americana ,grun41 #abb tabellaria ,grun41 #aai tryblionella ,hantzsch1 #aaf vermicularis 7,kuetz47 ,hantzsch1 #abj ,odontidium parasiticum ,wm4 ,sm41 #de tabellaria ,wm4 ,sm41 #de ,opephora1 #dc pacifica 7,grun47 ,petit1 #dc pinnata var4 lanceolata n4 var41 #dd schwartzii 7,grun47 ,petit1 #dc ,orthosira orichalcea ,wm4 ,sm41 #ae punctata ,wm4 ,sm41 #ae spinosa ,grev41 #ae ,paralia marina ,heib41 #ae sulcata 7,ehr47 ,cl41 #ae ,pinnularia1 #aja acrosphria 7,brb47 ,cl41 #ajh var4 turgidula ,grun481 #ajh stuarii ,cl41 #aje appendiculata 7,ag47 ,cl41 #ajf blandita n4 sp41 #ajh borealis ,ehr41 #aji var4 scalaris 7,ehr47 ,cl41 #aji braunii ,grun41 #ajf brbissonii 7,kuetz47 ,cl41 #ajg cardinaliculus ,cl41 #ajg cyprinus ,wm4 ,sm41 #ie dactylus ,ehr41 #ajc var4 dariana 7,a4 ,s47 ,cl41 #ajc var4 demerar ,cl41 #ajc divergens var4 elliptica ,grun41 #ajg gentilis 7,donk47 ,cl41 #ajc gibba 7,kuetz47 ,v4 ,h41 #aji interrupta forma stauroneiformis ,cl41 #ajf lata 7,brb47 ,wm4 ,sm41 #aji legumen ,ehr41 #ajg var481 #ajg leptosoma ,grun41 #aje major 7,kuetz47 ,wm4 ,sm41 #ajb var4 pulchella n4 var41 #ajb mesogongyla 7,ehr47 ,cl41 #aji mesolepta ,ehr41 #aje var4 stauroneiformis ,grun41 #aje microstauron 7,ehr47 ,cl41 #ajf molaris 7,grun47 ,cl41 #aje mormonorum ,grun41 #ajg nobilis ,ehr41 #ajc nodosa forma capitata ,cl41 #ajh parva 7,ehr47 ,cl41 #ajh permagna ,bail41 #hb polyonca 7,brb47 ,lewis1 #ajh rectangulata 7,greg47 ,cl41 #aaj socialis 7,palmer71 #ajd stauroptera 7,grun47 ,cl41 #aaj var4 interrupta forma stauroneiformis ,cl41 #aaj stomatophora 7,grun47 ,cl41 #aji subcapitata ,greg41 #aje var4 paucistriata ,grun41 #ajf tabellaria 7,ehr47 ,cl41 #aaj termes 7,ehr47 ,a4 ,s41 #ajf var4 stauroneiformis ,v4 ,h41 #ajf trigonocephala ,cl41 #ajc viridis ,nitzsch1 #ajd var4 caudata n4 var41 #ajd var4 fallax ,cl41 #ajd var481 #ajd ,plagiogramma1 #db obesum ,grev41 #dc pygmum ,grev41 #dc tessellatum ,grev41 #dc wallichianum ,grev41 #dc ,pleurosigma1 #gc stuarii ,brb41 #gd affine var4 fossilis ,grun41 #gd angulatum 7,quekett7 ,cl41 #gd balticum 7,ehr47 ,wm4 ,sm41 #ge formosum ,wm4 ,sm41 #gc hippocampus 7,ehr47 ,wm4 ,sm41 #ge naviculaceum ,brb41 #gd normanii var4 fossilis ,grun41 #gd obscurum ,wm4 ,sm41 #gd rigidum ,wm4 ,sm41 #ge simile ,grun41 #gf spencerii var4 acutiuscula ,grun41 #gf var4 kuetzingii ,grun41 #gf strigosum ,wm4 ,sm41 #gd virginiacum ,h4 ,l4 ,s41 #gd ,podocystis1 #abh adriatica ,kuetz41 #abi americana ,bail41 #abi ,podosira hormoides ,wm4 ,sm41 #ah maculata ,wm4 ,sm41 #ag ,podosphenia baileyi 7,edw47 ,lewis1 #dj ehrenbergii ,kuetz41 #dj lyngbyei ,kuetz41 #dj ,polymyxus1 #be coronalis ,l4 ,w4 ,bail41 #be ,pseudauliscus1 #bi radiatus 7,bail47 ,rattr41 #bi spinosus 7,christian7 ,rattr41 #bi ,pyxidicula1 #ai compressa ,bail41 #aaf var4 minor ,h4 ,l4 ,s41 #aaf cruciata ,ehr41 #ai radiata ,o',meara1 #ag ,rhabdonema1 #ce adriaticum ,kuetz41 #cf arcuatum 7,lyng47 ,kuetz41 #ce minutum ,kuetz41 #cf ,rhaphoneis1 #df amphiceros ,ehr41 #df var4 rhombica ,grun41 #df belgica var4 intermedia ,grun41 #df ,rhipidophora elongata ,kuetz41 #ci paradoxa ,kuetz41 #ci ,rhoicosphenia1 #ef curvata 7,kuetz47 ,grun41 #ef ,rhopalodia1 #aab gibba 7,kuetz47 ,mueller1 #aab ventricosa 7,kuetz47 ,mueller1 #aac ,schizonema cruciger ,wm4 ,sm41 #ajj dillwynii ,wm4 ,sm41 #gh grevillei ,ag41 #ii smithii ,kuetz41 #ie ,scoliopleura tumida 7,brb47 ,v4 ,h41 #ii ,scoliotropis1 #fi latestriata var4 amphora ,cl41 #fi ,stauroneis1 #hh acuta ,wm4 ,sm41 #hi americana ,a4 ,s41 #hi anceps ,ehr41 #hh var4 amphicephala 7,kuetz47 ,cl41 #hh var4 gracilis 7,ehr47 ,cl41 #hh crucicula 7,grun47 ,cl41 #hi exilis ,kuetz41 #ei frickei var4 angusta n4 var41 #hh legumen ,ehr41 #hi maculata ,bail41 #ij phoenicenteron ,ehr41 #hh salina ,wm4 ,sm41 #hi smithii ,grun41 #hi spicula ,hickie1 #ajj ,staurosira construens ,ehr41 #de ,stephanopyxis1 #ah appendiculata ,ehr41 #ah corona 7,ehr47 ,grun41 #ah turris 7,grev47 ,ralfs1 #ah ,striatella1 #cg interrupta 7,ehr47 ,heib41 #ch unipunctata 7,lyng47 ,ag41 #ch ,surirella1 #abd amphioxys ,wm4 ,sm41 #abd anceps ,lewis1 #abh angusta ,kuetz41 #abg arctissima ,a4 ,s41 #abh bifrons ,ehr41 #abd biseriata 7,ehr47 ,brb41 #abd cardinalis ,kitton1 #abf circumsuta ,bail41 #aah cruciata ,a4 ,s41 #abg crumena ,brb41 #abf davidsonii ,a4 ,s41 #abf delicatissima ,lewis1 #abh diaphana ,bleisch1 #abe elegans ,ehr41 #abe fastuosa ,ehr41 #abg febigerii ,lewis1 #abh gemma ,ehr41 #abe gracilis ,grun41 #abg guatimalensis ,ehr41 #abf intermedia ,lewis1 #abh linearis ,wm4 ,sm41 #abd moelleriana ,grun41 #abd oblonga ,ehr481 #abg ovalis ,brb41 #abf var4 pinnata 7,wm4 ,sm47 ,de ,toni1 #abf panduriformis ,wm4 ,sm41 #abf pinnata ,wm4 ,sm41 #abf var4 minuta ,grun41 #abf recedens ,a4 ,s41 #abg robusta ,ehr41 #abd splendida 7,ehr47 ,kuetz41 #abe striatula ,turpin1 #abe tenera ,greg41 #abe ,synedra1 #dg acus ,kuetz41 #dh affinis ,kuetz41 #ej var4 parva 7,kuetz47 ,v4 ,h41 #ej var4 tabulata 7,ag47 ,v4 ,h41 #ej biceps 7,kuetz47 ,a4 ,s41 #dh capitata ,ehr41 #dh danica ,kuetz41 #dh fulgens 7,grev47 ,wm4 ,sm41 #ej goulardi ,brb41 #dh gracilis ,kuetz41 #ej oxyrhynchus var4 undulata ,grun41 #dh pulchella 7,ralfs7 ,kuetz41 #dh var4 abnormis ,macchiati81 #dh var4 flexella n4 var41 #di radians ,kuetz41 #di ulna 7,nitzsch7 ,ehr41 #dg vaucheri var4 parvula 7,kuetz47 ,rab41 #di ,tabellaria1 #cf fenestrata 7,lyng471 #cf flocculosa 7,roth7 ,kuetz41 #cf ,terpsino1 #cd americana 7,bail47 ,ralfs1 #cd nov-csare ,boyer1 #cd ,tessella interrupta ,ehr41 #ch ,trachyneis1 #gi aspera var4 intermedia ,grun41 #gi ,trachysphenia1 #dg australis ,petit1 #dg ,triceratium alternans ,bail41 #cc favus ,ehr41 #ca obtusum ,br41 #cc pileotus ,ehr41 #cj punctatum ,br41 #cc sculptum ,shad41 #cc ,trinacria1 #cj pileolus 7,ehr47 ,grun41 #cj ,tripodiscus argus ,ehr41 #bf ,tropidoneis1 #fh lepidoptera 7,greg47 ,cl41 #fi ,tryblionella punctata ,wm4 ,sm41 #aaf scutellum ,wm4 ,sm41 #aah ,vibrio paxillifer ,o4 ,f4 ,mueller1 #aai ,,plates ,,plate #a ,,meloseira #c-d ,meloseira roeseana var4 epidendron 7,ehr47 ,grun4 #ae #e-f ,meloseira roeseana ,rab4 #ae #h-i ,meloseira distans 7,ehr47 ,kuetz4 #ad #aj ,meloseira granulata 7,ehr47 ,ralfs #ae #aa-ab ,meloseira sulcata ,kuetz4 #ae #ae-af-ag ,meloseira undulata 7,ehr47 ,kuetz4 #ae ,,gaillonella #ac-ad ,gaillonella nummuloides 7,dillw47 ,bory #af ,,lysigonium #g ,lysigonium moniliforme 7,muell47 ,link4 #af #ah-ai ,lysigonium varians 7,ag47 ,de ,toni #ag ,,hyalodiscus #bj ,hyalodiscus scoticus 7,kuetz47 ,grun4 #ah #ba ,hyalodiscus radiatus var4 arctica ,grun4 #ag #bb ,hyalodiscus stelliger ,bail4 #ag ,,note4--,the figures in all of the plates1 except when otherwise noted1 are magnified #hjj diameters4 ,illustration3 ,,plate #a ,,plate #b ,,stephanopyxis #a-b ,stephanopyxis turris 7,grev47 ,ralfs #ah #c ,stephanopyxis corona 7,ehr47 ,grun4 #ah ,,cyclotella #d ,cyclotella meneghiniana var4 stelligera ,cl4 and ,grun4 #bj #e-f ,cyclotella operculata 7,ag47 ,kuetz4 #bj #g ,cyclotella comta 7,ehr47 ,kuetz4 #bj #h ,cyclotella meneghiniana ,kuetz4 #ai #i ,cyclotella striata 7,kuetz47 ,grun4 #ai #aj ,cyclotella stylorum 7,br487 ,v4 ,h4 #bj #aa ,cyclotella antiqua ,wm4 ,sm4 #bj #ab ,cyclotella meneghiniana var4 stellulifera ,cl4 and ,grun4 #bj ,,coscinodiscus #ac ,coscinodiscus denarius ,a4 ,s4 #bb #ad ,coscinodiscus excentricus ,ehr4 #ba #ae-ag ,coscinodiscus subtilis ,ehr4 #ba #af ,coscinodiscus asteromphalus ,ehr4 #bc #ah ,coscinodiscus nitidus ,greg4 #ba #ai ,coscinodiscus nitidulus ,grun4 #ba #bj ,coscinodiscus excentricus var4 perpusilla ,grun4 8 #ba ,illustration3 ,,plate #b ,,plate #c ,,coscinodiscus--,continued #a-aa ,coscinodiscus radiatus ,ehr4 #bc #b ,coscinodiscus velatus ,ehr4 #bb #c ,coscinodiscus biangulatus ,a4 ,s4 #bc #d ,coscinodiscus subaulacodiscoidalis ,rattr4 #bc #e ,coscinodiscus lewisianus ,grev4 #bd #g ,coscinodiscus argus ,ehr4 #bc #h ,coscinodiscus lineatus ,ehr4 #ba #i ,coscinodiscus marginatus ,ehr4 #bb #aj ,coscinodiscus oculus-iridis ,ehr4 #bc ,,actinocyclus #f ,actinocyclus ellipticus var4 delawarensis n4 var4 #bg ,illustration3 ,,plate #c ,,plate #d ,,actinoptychus #a-d-f ,actinoptychus undulatus 7,kuetz47 ,ralfs4 #bd #b ,actinoptychus undulatus 7inner stratum7 #bd #c ,actinoptychus heliopelta ,grun4 var48 #be #e ,actinoptychus vulgaris var4 interrupta n4 var4 #bd ,,polymyxus #g ,polymyxus coronalis ,l4 ,w4 ,bail4 #be ,,aulacodiscus #h ,aulacodiscus argus 7,ehr47 ,a4 ,s4 #bf ,illustration3 ,,plate #d ,,plate #e ,,euodia #a ,euodia gibba ,bail4 #cd ,,polymyxus #b ,polymyxus coronalis ,l4 ,w4 ,bail41 zone view #be ,,eupodiscus #c ,eupodiscus radiatus ,bail4 #bh ,,auliscus #d ,auliscus clatus ,bail4 #bi #e ,auliscus sculptus 7,wm4 ,sm47 ,ralfs #bi #f ,auliscus punctatus ,bail4 #bh #g ,auliscus 7intermediate form between ,a4 clatus and ,a4 sculptus7 #bi #h ,auliscus pruinosus ,bail4 #bh ,,pseudauliscus #i ,pseudauliscus radiatus 7,bail47 ,rattr4 #bi #aj ,pseudauliscus spinosus 7,christian7 ,rattr4 #bi ,illustration3 ,,plate #e ,,plate #f ,,actinocyclus #a ,actinocyclus barkleyi var4 aggregata ,rattr4 #bg #b ,actinocyclus moniliformis ,ralfs4 #bg ,,biddulphia #c ,biddulphia antediluviana 7,ehr47 ,v4 ,h4 #cb #e ,biddulphia reticulum 7,ehr47 #cc #f ,biddulphia favus 7,ehr47 ,v4 ,h4 #ca #g-h ,biddulphia alternans 7,bail47 ,v4 ,h4 #cc ,,trinacria #i ,trinacria pileolus 7,ehr47 ,grun4 #cj ,,ditylum #d ,ditylum intricatum 7,west7 ,grun4 #cj ,,terpsino #aj ,terpsino americana 7,bail47 ,ralfs4 #cd #aa ,terpsino nov-csare ,boyer #cd ,illustration3 ,,plate #f ,,plate #g ,,biddulphia #a-b-c-d ,biddulphia biddulphiana 7,smith7 #ca #e ,biddulphia rhombus 7,ehr47 ,wm4 ,sm4 #cb #f ,biddulphia granulata ,roper #cb #g ,biddulphia turgida 7,ehr47 ,wm4 ,sm4 #cb #h ,biddulphia smithii 7,ralfs7 ,v4 ,h4 #cb #i ,biddulphia lvis ,ehr4 #cc #aj ,biddulphia lvis ,ehr4 ,sporangial frustules 7#bfj diam47 #cc ,,eunotogramma #aa ,eunotogramma lve ,grun4 #cc ,illustration3 ,,plate #g ,,plate #h ,,rhabdonema #a-b-c ,rhabdonema arcuatum 7,lyng47 ,kuetz4 #ce #d-e-f ,rhabdonema adriaticum ,kuetz4 #cf #g ,rhabdonema minutum ,kuetz4 #cf ,,tabellaria #h-i-aj ,tabellaria flocculosa 7,roth7 ,kuetz4 #cf #aa-ab ,tabellaria fenestrata 7,lyng47 ,kuetz4 #cf ,,grammatophora #ac-ad ,grammatophora marina var4 subtilissima 7,bail47 ,v4 ,h4 #cg #ae-af ,grammatophora angulosa var4 hamulifera 7,kuetz47 ,grun4 #cg #ag-ah ,grammatophora marina 7,lyng47 ,kuetz4 #cg #ai-bj ,grammatophora islandica ,ehr4 #cg #ba ,grammatophora serpentina ,ralfs4 #cg ,,striatella #bb-bc ,striatella unipunctata 7,lyng47 ,ag4 #ch #bd ,striatella interrupta 7,ehr47 ,heib4 #ch ,,attheya #be ,attheya decora ,west #ch ,illustration3 ,,plate #h ,,plate #i ,,licmophora #a-b ,licmophora flabellata 7,carm47 ,ag4 #ci #c-d ,licmophora lyngbyei ,kuetz4 #dj #e ,licmophora ehrenbergii 7,kuetz47 ,grun4 #dj #f-g ,licmophora paradoxa 7,lyng47 ,ag4 #ci #h-i ,licmophora ovulum ,mer4 #ci #aj ,licmophora baileyi 7,edw47 ,grun4 #dj #aa ,licmophora gracilis 7,ehr47 ,grun4 #ci #ab-ac ,licmophora gracilis var4 elongata 7,kuetz47 ,de ,toni #ci #ad-ae ,licmophora tincta 7,ag47 ,grun4 #dj ,illustration3 ,,plate #i ,,plate #aj ,,meridion #a-b-c ,meridion circulare 7,grev47 ,ag4 #dj ,,diatoma #d ,diatoma vulgare var4 grande 7,wm4 ,sm47 ,grun4 #db #e-f ,diatoma anceps 7,ehr47 ,kirchn4 #db #g-h ,diatoma hiemale 7,lyng47 ,heib4 #db #i-aj ,diatoma vulgare ,bory4 #db ,,plagiogramma #aa ,plagiogramma tessellatum ,grev4 #dc #ab ,plagiogramma obesum ,grev4 #dc #ac ,plagiogramma pygmum ,grev4 #dc #ad ,plagiogramma wallichianum ,grev4 #dc ,,eunotogramma #ae ,eunotogramma lve ,grun4 #cc ,,opephora #af-ai ,opephora schwartzii 7,grun47 ,petit4 #dc #ag ,opephora pinnata var4 lanceolata n4 var4 #dd #ah ,opephora pacifica 7,grun47 ,petit4 #dc ,,fragilaria #bj-ba ,fragilaria virescens ,ralfs4 #dd #bb-bc ,fragilaria arctica ,grun4 #dd #bd-be-bg-bh-bi ,fragilaria undata ,wm4 ,sm4 #dd #bf ,fragilaria undata ,wm4 ,sm41 var48 #dd #cj ,fragilaria construens 7,ehr47 ,grun4 #de #ca ,fragilaria harrisonii 7,wm4 ,sm47 ,grun4 #de #cd ,fragilaria capucina var4 mesolepta ,rab4 #de #ce ,fragilaria parasitica 7,wm4 ,sm47 #de #cf ,fragilaria sp4 8 #de #cg ,fragilaria linearis ,cstr4 #de ,,rhaphoneis #ch ,rhaphoneis amphiceros ,ehr4 #df #ci-dj ,rhaphoneis amphiceros var4 rhombica ,grun4 #df #da ,rhaphoneis belgica var4 intermedia ,grun4 #df ,,synedra #cb-cc ,synedra radians ,kuetz4 #di ,illustration3 ,,plate #aj ,,plate #aa ,,synedra--,continued #a-e-f ,synedra ulna 7,nitzsch7 ,ehr4 ,sporangial #dg #b ,synedra danica ,kuetz4 #dh #c ,synedra biceps 7,kuetz47 ,a4 ,s4 #dh #d-g-aa ,synedra ulna 7,nitzsch7 ,ehr4 #dg #h ,synedra capitata ,ehr4 #dh #i-ah ,synedra acus ,kuetz4 #dh #aj ,synedra fulgens 7,grev47 ,wm4 ,sm4 #ej #ab-ac ,synedra goulardi ,brb4 #dh #ad-ae-af ,synedra pulchella 7,ralfs7 ,kuetz4 #dh #ag ,synedra pulchella var4 abnormis ,macchiati8 #dh ,illustration3 ,,plate #aa ,,plate #ab ,,synedra--,continued #a ,synedra oxyrhynchus var4 undulata ,grun4 #dh #b ,synedra pulchella var4 flexella n4 var4 #di #c ,synedra affinis ,kuetz4 #ej #d ,synedra affinis var4 tabulata 7,ag47 ,v4 ,h4 #ej #e-f ,synedra vaucheri var4 parvula 7,kuetz47 ,rab4 #di #g ,synedra affinis var4 parva 7,kuetz47 ,v4 ,h4 #ej #h ,synedra radians 7,kuetz47 ,h4 ,l4 ,s4 #di ,,dimerogramma #i-aj ,dimerogramma marinum 7,greg47 #df #aa ,dimerogramma surirella 7,ehr47 ,grun4 #df #ab-ac-ad ,dimerogramma minus 7,greg47 ,ralfs4 #dg ,,trachysphenia #ae ,trachysphenia australis ,petit4 #dg ,,actinella #af-ag-ah ,actinella punctata ,lewis4 #ed ,,asterionella #ai-bj-ba ,asterionella formosa ,hass4 #ej #bb ,asterionella inflata ,heib4 #ej ,,eunotia #bc ,eunotia hemicyclus 7,ehr47 ,ralfs #ec #bd-be ,eunotia lunaris 7,ehr47 ,grun4 #ec ,illustration3 ,,plate #ab ,,plate #ac ,,eunotia--,continued #a-b ,eunotia major 7,wm4 ,sm47 ,rab4 #ea #c ,eunotia gracilis 7,ehr47 ,rab4 #ea #d ,eunotia major 7,wm4 ,sm47 ,rab4 7intermediate form7 #ea #e ,eunotia prrupta ,ehr4 #ec #f-g ,eunotia pectinalis 7,kuetz47 #eb #h-aj ,eunotia pectinalis var4 undulata ,ralfs #eb #i ,eunotia pectinalis var4 solierolii 7,kuetz47 #eb #aa ,eunotia luna ,ehr4 var48 #eb #ab ,eunotia pectinalis var4 ventricosa ,grun4 #eb #ac ,eunotia robusta ,ralfs 7,e4 scalaris ,ehr47 #ec #ad ,eunotia robusta ,ralfs 7,e4 prioritis ,ehr47 #ec #ae ,eunotia robusta ,ralfs 7,e4 decadon ,ehr47 #ec #af ,eunotia robusta ,ralfs 7,e4 octodon ,ehr47 #ec #ag-bb ,eunotia robusta ,ralfs 7,e4 heptodon ,ehr47 #ec #ah ,eunotia bactriana ,ehr4 #ed #ai ,eunotia prrupta var4 bidens ,grun4 #ec #bj ,eunotia bidentula ,wm4 ,sm4 #ed #ba ,eunotia robusta ,ralfs 7,e4 diadema ,ehr47 #ec #bc ,eunotia prrupta ,ehr4 var48 #ec #bd ,eunotia robusta ,ralfs 7,e4 triodon ,ehr47 #ec #be ,eunotia robusta ,ralfs 7,e4 tetraodon ,ehr47 #ec #bf ,eunotia formica ,ehr4 var48 #ed #bg ,eunotia biceps ,ehr4 #ec #bh-bi ,eunotia sp48 #ed #cj-ca ,eunotia veneris ,kuetz4 #eb #cb ,eunotia nymanniana ,grun4 #ea ,illustration3 ,,plate #ac ,,plate #ad ,,amphiprora #a-b ,amphiprora pulchra ,bail4 #fh #c ,amphiprora alata ,kuetz4 #fh #d ,amphiprora conspicua ,grev4 #fh #e ,amphiprora paludosa ,wm4 ,sm4 #fh #f-g ,amphiprora ornata ,bail4 #fh ,,tropidoneis #h-i ,tropidoneis lepidoptera 7,greg47 ,cleve4 #fi ,,scoliotropis #aj-aa ,scoliotropis latestriata var4 amphora ,cleve4 #fi ,illustration3 ,,plate #ad ,,plate #ae ,,amphora #a ,amphora robusta ,greg4 #fe #c ,amphora crassa ,greg4 #fe #d ,amphora obtusa ,greg4 #fg #e-f-ai ,amphora proteus ,greg4 #fe #g ,amphora ovalis 7,brb47 ,kuetz4 #fe #h-ah ,amphora coffiformis 7,ag47 ,kuetz4 #ff #i-aj ,amphora lineolata ,ehr4 #ff #aa ,amphora areolata ,grun4 #ff #ab-ba ,amphora ostrearia ,brb4 #ff #ac ,amphora lvis ,greg4 #ff #ad-ae ,amphora ocellata var4 cingulata ,cleve4 #fg #af ,amphora angusta var4 culensteinii ,grun4 #fg #ag ,amphora arenaria ,donk4 #fg #bj ,amphora acuta ,greg4 #ff ,,auricula #b ,auricula mucronata 7,h4 ,l4 ,smith7 ,peragallo #fi ,illustration3 ,,plate #ae ,,plate #af ,,achnanthes #a-b ,achnanthes longipes ,ag4 #eh #c ,achnanthes brevipes ,ag4 #ei #d-e-f ,achnanthes subsessilis ,kuetz4 #ei #g-h ,achnanthes inflata 7,kuetz47 ,grun4 #ei #i ,achnanthes coarctata 7,brb47 ,grun4 #ei #aj-aa-ab ,achnanthes lanceolata 7,brb47 ,grun4 #ei #ac ,achnanthes danica 7,floegel7 ,grun4 7lower valve7 #fj #ad-ae ,achnanthes exigua ,grun4 #ei #af-ag ,achnanthes linearis forma curta ,h4 ,l4 ,smith #ei ,,cocconeis #ah ,cocconeis scutellum var48 #eg #ai-bj ,cocconeis placentula ,ehr4 #eg #ba ,cocconeis scutellum ,ehr4 7upper valve7 #eg #bb ,cocconeis dirupta ,greg4 7lower valve7 #eh #bc-bd ,cocconeis pediculus ,ehr4 #eg #be-bf ,cocconeis pellucida ,grun4 #eh #bg-bh ,cocconeis scutellum var4 ornata ,grun4 #eg #bi ,cocconeis placentula var4 lineata 7,ehr47 ,v4 ,h4 #eh ,,anorthoneis #cj-ca ,anorthoneis excentrica 7,donk47 ,grun4 #ef ,illustration3 ,,plate #af ,,plate #ag ,,frustulia #a ,frustulia lewisiana 7,grev47 ,de ,toni #gg #b ,frustulia rhomboides 7,ehr47 ,de ,toni #gg #c ,frustulia rhomboides var4 amphipleuroides ,grun4 #gg #d ,frustulia vulgaris 7,thwaites7 ,de ,toni #gg #e ,frustulia interposita 7,lewis7 ,de ,toni #gh #f ,frustulia rhomboides var4 saxonica 7,rab47 ,de ,toni #gg ,,brebissonia #g ,brbissonia boeckii 7,kuetz47 ,grun4 #gi #h ,brbissonia palmerii n4 sp4 #hj ,,amphipleura #i ,amphipleura pellucida ,kuetz4 #gh #aj-aa ,amphipleura rutilans 7,trentepohl7 ,cl4 #gh ,,anomoeoneis #ab ,anomoeoneis serians 7,brb47 ,cl4 #hj #ac ,anomoeoneis serians forma minor #hj #ad ,anomoeoneis follis 7,ehr47 ,cl4 #hj ,,trachyneis #ae ,trachyneis aspera var4 intermedia ,grun4 #gj ,,mastogloia #af ,mastogloia kinsmanii ,lewis #hg #ag ,mastogloia angulata ,lewis #hg #ah ,mastogloia lanceolata ,thwaites #hg #ai ,mastogloia smithii ,thwaites #hg #bj ,mastogloia elegans ,lewis #hg #ba-bb-bc ,mastogloia apiculata ,wm4 ,sm4 #hg #bd ,mastogloia exigua ,lewis #hg ,illustration3 ,,plate #ag ,,plate #ah ,,cymbella #a ,cymbella aspera 7,ehr47 ,cl4 #fa #b ,cymbella cymbiformis 7,kuetz47 ,brb4 #fb #c ,cymbella cistula 7,hempr47 ,kirchn4 #fb #d ,cymbella lanceolata 7,ehr47 ,kirchn4 #fb #e ,cymbella mexicana 7,ehr47 ,a4 ,s4 #fb #f ,cymbella naviculiformis ,auerswald4 #fj #g ,cymbella tumida 7,brb47 ,v4 ,h4 #fb #h ,cymbella philadelphica n4 sp4 #fc #i ,cymbella ehrenbergii ,kuetz4 #fj #aj ,cymbella heteropleura 7,ehr47 ,kuetz4 #fj #aa ,cymbella rhomboidea n4 sp4 #fc #ab ,cymbella turgida 7,greg47 ,cl4 var48 #fc #ac ,cymbella sinuata ,greg4 #fa #ad ,cymbella ventricosa ,kuetz4 #fb #ae-ai ,cymbella excisa 7,kuetz47 ,de ,toni4 #fa #af ,cymbella amphicephala ,ngeli4 #fa #ag ,cymbella cuspidata ,kuetz4 #fj #ah ,cymbella affinis ,kuetz4 #fa #bj ,cymbella gracilis 7,rab47 ,cl4 #fd #ba ,cymbella prostrata 7,berk47 ,cl4 #fc #bb ,cymbella ventricosa ,kuetz48 #fb #bc ,cymbella turgida 7,greg47 ,cl4 #fc #bd ,cymbella triangulum 7,ehr47 ,cl4 #fc #be ,cymbella lacustris 7,ag47 ,cl4 #fd ,illustration3 ,,plate #ah ,,plate #ai ,,gomphoneis #a ,gomphoneis mamilla 7,ehr47 ,cl4 #gj #b ,gomphoneis herculaneum 7,ehr47 ,cl4 #gj ,,gomphonema #c ,gomphonema montanum ,schum4 #ga #d ,gomphonema geminatum ,lyng4 #ga #e ,gomphonema acuminatum var4 turris 7,ehr47 ,cl4 #ga #f-ab ,gomphonema lanceolatum var4 insignis 7,greg47 ,cl4 #ga #g ,gomphonema acuminatum var4 coronata 7,ehr47 ,cl4 #ga #h ,gomphonema constrictum ,ehr4 #gb #i-aj ,gomphonema sphrophorum ,ehr4 #gb #aa ,gomphonema acuminatum var4 turris 7,ehr47 ,cl48 #ga #ac ,gomphonema ventricosum ,greg4 #gc #ad ,gomphonema intricatum ,kuetz4 #gb #ae ,gomphonema quale ,greg4 #gb #af ,gomphonema sarcophagus ,greg4 #gb #ag ,gomphonema parvulum var4 micropus 7,kuetz47 ,cl4 #gc #ah-ai ,gomphonema angustatum ,kuetz4 #gb #bj ,gomphonema acuminatum var4 trigonocephala 7,ehr47 ,cl4 #ga #ba ,gomphonema augur ,ehr4 #gb #bb ,gomphonema capitatum ,ehr4 #gb #bc ,gomphonema olivaceum ,lyng4 #gc #bd ,gomphonema brasiliense var4 demerar ,grun48 #gc ,,rhoicosphenia #be-bf-bg ,rhoicosphenia curvata 7,kuetz47 ,grun4 #ef ,illustration3 ,,plate #ai ,,plate #bj ,,dictyoneis #a ,dictyoneis marginata var4 maxima n4 var4 #gi #b ,dictyoneis marginata var4 commutata ,cleve4 #gi #c ,dictyoneis marginata var4 typica ,cleve4 #gh ,,diploneis #d ,diploneis crabro var4 pandura 7,brb47 ,cl4 #he #f ,diploneis campylodiscus 7,grun47 ,cl4 #hf #g-h ,diploneis gruendleri 7,a4 ,s47 ,cl4 #he #i ,diploneis crabro ,ehr4 var48 #he #aj ,diploneis excentrica n4 sp4 #he #aa ,diploneis fusca var4 delicata 7,a4 ,s47 ,cl4 #he #ab ,diploneis puella 7,schum47 ,cl4 #he #ac ,diploneis crabro var4 pandurella ,cl48 #he #ad ,diploneis elliptica 7,kuetz47 ,cl4 #hd #ae ,diploneis crabro var4 expleta 7,a4 ,s47 ,cl4 #he #af ,diploneis geminata 7,grev47 ,cl4 #hf #ag ,diploneis smithii 7,brb47 ,cl4 #hd ,,navicula #e ,navicula lyra ,ehr4 var48 #ic ,illustration3 ,,plate #bj ,,plate #ba ,,caloneis #a ,caloneis permagna 7,bail47 ,cl4 #hb #b ,caloneis permagna var4 lewisiana n4 var4 #hb #c ,caloneis silicula 7,ehr47 ,cl4 #ha #d ,caloneis silicula var4 inflata 7,grun47 ,cl4 #ha #e ,caloneis brevis var4 vexans 7,grun47 ,cl4 #hb #f-g ,caloneis wardii ,cl4 #hb #h ,caloneis trinodis 7,lewis7 #ha #i ,caloneis trinodis 7,lewis7 var48 #ha #aj ,caloneis powellii 7,lewis7 ,cl4 #hc #ah ,caloneis formosa 7,greg47 ,cl4 #hb ,,neidium #aa ,neidium affine 7,ehr47 ,pfitzer #hc #ab ,neidium affine var4 genuina forma minor ,cl4 #hc #ac ,neidium affine var4 amphirhyncus 7,ehr47 ,cl4 #hc #ad ,neidium amphigomphus 7,ehr47 ,pfitzer4 #hc #ae ,neidium hitchcockii 7,ehr47 ,cl4 #hd #af ,neidium productum 7,wm4 ,sm47 ,cl4 #hc #ag ,neidium iridus 7,ehr47 ,cl4 #hd ,illustration3 ,,plate #ba ,,plate #bb ,,pleurosigma #a ,pleurosigma strigosum ,wm4 ,sm4 #gd #b ,pleurosigma rigidum ,wm4 ,sm4 #ge #c ,pleurosigma angulatum 7,quekett7 ,cl4 #gd #d ,pleurosigma obscurum ,wm4 ,sm4 #gd #e ,pleurosigma formosum ,wm4 ,sm4 #gc #f ,pleurosigma naviculaceum ,brb4 #gd #g ,pleurosigma stuarii ,brb4 #gd #h ,pleurosigma virginiacum ,h4 ,l4 ,smith #gd ,illustration3 ,,plate #bb ,,plate #bc ,,gyrosigma #a ,gyrosigma strigilis 7,wm4 ,sm47 ,cl4 #gf #b ,gyrosigma balticum 7,ehr47 ,cl4 #ge #c ,gyrosigma hippocampus 7,ehr47 #ge #d ,gyrosigma simile 7,grun47 #gf #e ,gyrosigma acuminatum 7,kuetz47 ,cl4 #gf #f ,gyrosigma scalproides 7,rab47 ,cl4 #gf #g ,gyrosigma parkeri var4 stauroneioides ,grun4 #ge #h ,gyrosigma spencerii var4 nodifera ,grun4 #gf #i ,gyrosigma fasciola 7,ehr47 ,cl4 #gg ,illustration3 ,,plate #bc ,,plate #bd ,,navicula #a ,navicula maculata 7,bail47 ,cl4 #ij #b ,navicula prtexta ,ehr4 #ib #c ,navicula latissima ,greg4 #ij #d ,navicula irrorata ,grev4 #ic #e ,navicula latissima var4 elongata 7,pant47 ,cl4 #ia #f ,navicula fuchsii ,pant4 #ia ,illustration3 ,,plate #bd ,,plate #be ,,navicula #a ,navicula tumida 7,brb47 ,cl4 #ii #b ,navicula brasiliensis var4 bicuneata ,cl4 forma constricta4 #ib #c ,navicula delawarensis ,grun4 #ib #d-f ,navicula pusilla ,wm4 ,sm4 #ia #e ,navicula humerosa ,brb4 #ia #g ,navicula spectabilis var4 emarginata ,cl4 #id #h ,navicula pusilla var4 subcapitata n4 var4 #ia #i ,navicula punctulata ,wm4 ,sm4 #ib #aj ,navicula lyra ,ehr4 #ic #aa ,navicula hennedyi var4 manca ,a4 ,s4 #ic #ab ,navicula hennedyi ,wm4 ,sm4 #ic #ac ,navicula lyra var4 dilatata ,a4 ,s4 #ic #ad ,navicula yarrensis ,grun4 #aja #ae ,navicula yarrensis ,grun4 7smaller form7 #aja #af ,navicula yarrensis ,grun4 var48 #aja ,illustration3 ,,plate #be ,,plate #bf ,,navicula #a-b ,navicula cuspidata ,kuetz4 #ajj #c ,navicula cuspidata var4 ambigua 7,ehr47 ,cl4 #ajj #d ,navicula spicula 7,hickie7 ,cl4 #ajj #e ,navicula integra ,wm4 ,sm4 #ii #f ,navicula mutica ,kuetz4 #ig #h ,navicula americana ,ehr4 #ih #i ,navicula pupula var4 bacillarioides ,grun4 #ih #aj ,navicula bacillum ,ehr4 #ih #aa ,navicula semen ,ehr4 #ih #ab ,navicula atomus ,ngeli4 #ajj #ac ,navicula minima ,grun4 #ih #ad ,navicula ramosissima 7,ag47 ,cl4 #ie #ae ,navicula crucigera 7,wm4 ,sm47 ,cl4 #ajj #af ,navicula viridula var4 rostellata ,kuetz4 #ie #ag ,navicula radiosa ,kuetz4 #id #ai ,navicula gracilis var4 schizonemoides 7,ehr47 ,v4 ,h4 #ie #bj ,navicula peregrina ,ehr4 #id #ba ,navicula cyprinus 7,wm4 ,sm47 #ie #bb ,navicula reinhardtii ,grun4 #ie #bc ,navicula lanceolata var4 arenaria 7,donk47 ,cl4 #ie #bd ,navicula salinarum ,grun4 #ie #be ,navicula gastrum ,ehr4 #if #bf ,navicula anglica ,ralfs4 #if ,,diploneis #g ,diploneis oculata 7,brb47 ,cl4 #hf ,,stauroneis #ah ,stauroneis frickei var4 angusta n4 var4 #hh ,illustration3 ,,plate #bf ,,plate #bg ,,stauroneis--,continued #a ,stauroneis phoenicenteron ,ehr4 #hh #b ,stauroneis acuta ,wm4 ,sm4 #hi #c ,stauroneis americana ,a4 ,s4 #hi #d ,stauroneis anceps var48 #hh #e ,stauroneis anceps var4 gracilis 7,ehr47 ,cl4 #hh #f ,stauroneis salina ,wm4 ,sm4 #hi #g ,stauroneis anceps var4 amphicephala 7,kuetz47 ,cl4 #hh #h ,stauroneis anceps var48 #hh #i ,stauroneis anceps var48 #hh #aj ,stauroneis crucicula 7,grun47 ,cl4 #hi #aa ,stauroneis smithii ,grun4 #hi ,,navicula #ab ,navicula lacustris ,greg4 #ib #ac ,navicula hasta ,pant4 #ig #ad ,navicula hasta var4 punctata n4 var4 #ig #ae ,navicula punctata var4 asymmetrica ,lagerstedt #ib #af ,navicula dicephala ,wm4 ,sm4 #if #ag ,navicula placenta ,ehr4 #id #ah-ai ,navicula inflexa ,greg4 #if #bj ,navicula pinnata ,pant48 #if #ba ,navicula oblonga ,kuetz4 #ig #bb ,navicula pennata ,a4 ,s4 #if #bc ,navicula pygma ,kuetz4 #id #bd ,navicula humilis ,donk4 #if ,illustration3 ,,plate #bg ,,plate #bh ,,pinnularia #a ,pinnularia nobilis ,ehr4 #ajc #b ,pinnularia major var4 pulchella n4 var4 #ajb #c ,pinnularia dactylus ,ehr4 #ajc #d ,pinnularia major 7,kuetz47 ,wm4 ,sm4 #ajb ,illustration3 ,,plate #bh ,,plate #bi ,,pinnularia--,continued #a ,pinnularia gentilis 7,donk47 ,cl4 #ajc #b ,pinnularia viridis ,nitzsch4 #ajd #c ,pinnularia dactylus var4 dariana 7,a4 ,s47 ,cl4 #ajc #d ,pinnularia viridis var4 fallax ,cl4 #ajd #e ,pinnularia socialis ,palmer #ajd #f ,pinnularia stuarii ,cl4 #aje #g ,pinnularia rectangulata 7,greg47 ,cl4 #aaj #h ,pinnularia trigonocephala ,cl4 #ajc #i ,pinnularia major 7,kuetz47 ,wm4 ,sm4 7small form near ,p4 viridis7 #ajb #aj ,pinnularia dactylus var4 demerar ,cl4 #ajc #aa ,pinnularia mormonorum 7,grun47 #ajg #ab ,pinnularia brbissonii 7,kuetz47 ,cl4 #ajg #ac ,pinnularia mesolepta ,ehr4 #aje #ad ,pinnularia termes var4 stauroneiformis ,v4 ,h4 #ajf #ae ,pinnularia molaris 7,grun47 ,cl4 #aje #af ,pinnularia braunii ,grun4 #ajf #ag ,pinnularia termes 7,ehr47 ,a4 ,s4 #ajf #ah ,pinnularia appendiculata 7,ag47 ,cl4 #ajf #ai ,pinnularia microstauron 7,ehr47 ,cl4 var48 #ajf #bj ,pinnularia subcapitata ,greg4 #aje ,illustration3 ,,plate #bi ,,plate #cj ,,pinnularia--,continued #a ,pinnularia cardinaliculus ,cl4 #ajg #b ,pinnularia viridis var4 fallax ,cl48 7var4 ,b41 ,wm4 ,sm4874 #ajd #c ,pinnularia legumen ,ehr4 #ajg #d ,pinnularia legumen var48 #ajg #e ,pinnularia gibba 7,kuetz47 ,v4 ,h4 #aji #f ,pinnularia mesogongyla 7,ehr47 ,cl4 #aji #g ,pinnularia acrosphria 7,brb47 ,cl4 #ajh #h ,pinnularia acrosphria var4 turgidula ,grun4 #ajh #i ,pinnularia tabellaria 7,ehr47 ,cl4 var48 #aaj #aj ,pinnularia leptosoma ,grun4 #aje #aa ,pinnularia stauroptera var4 interrupta ,cl4 #aaj #ab ,pinnularia stomatophora 7,grun47 ,cl4 #aji #ac ,pinnularia stauroptera 7,grun47 ,cl4 #aaj #ad ,pinnularia parva 7,ehr47 ,cl4 var48 #ajh #ae-ai ,pinnularia nodosa forma capitata ,cl4 #ajh #af ,pinnularia subcapitata var4 paucistriata ,grun4 #aje #ag ,pinnularia viridis ,nitzsch var4 #ajd #ah ,pinnularia viridis var4 caudata n4 var4 #ajd #bj ,pinnularia mesolepta var4 stauroneiformis ,grun4 #aje #ba ,pinnularia polyonca 7,brb47 ,lewis4 #ajh #bb ,pinnularia borealis ,ehr4 #aji #bc ,pinnularia lata 7,brb47 ,wm4 ,sm4 #aji #bd ,pinnularia borealis var4 scalaris 7,ehr47 ,cl4 #aji #be ,pinnularia blandita n4 sp4 #ajh ,illustration3 ,,plate #cj ,,plate #ca ,,navicula #a ,navicula elegans ,wm4 ,sm4 #aja #b ,navicula elegans var4 cuspidata ,cl4 #aja #c-d ,navicula grevillei 7,ag47 ,cl4 #ii #e ,navicula libellus ,greg4 #ii #f-g ,navicula palpebralis ,brb4 #aja #h ,navicula rhyncocephala ,kuetz4 #ig #i ,navicula cryptocephala ,kuetz4 #ig #aj ,navicula longa 7,greg47 ,ralfs4 #ig ,,pinnularia #aa ,pinnularia brbissonii 7,kuetz47 ,cl4 #ajg #ab ,pinnularia borealis ,ehr4 #aji #ac ,pinnularia divergens var4 elliptica ,grun4 #ajg ,,epithemia #ad ,epithemia turgida 7,ehr47 ,kuetz4 #aaa #ae-ba ,epithemia argus ,kuetz4 #aaa #af ,epithemia argus var48 #aaa #ag ,epithemia muelleri ,a4 ,s4 #aaa #ah ,epithemia zebra var4 proboscidea 7,kuetz47 ,grun4 #aab #ai ,epithemia gibberula var4 producta ,grun4 #aab #bj ,epithemia musculus ,kuetz4 #aab #bb ,epithemia musculus var4 constricta 7,brb47 ,v4 ,h4 #aab ,,rhopalodia #bc ,rhopalodia gibba 7,kuetz47 ,mueller #aab #bd ,rhopalodia ventricosa 7,kuetz47 ,mueller #aac ,illustration3 ,,plate #ca ,,plate #cb ,,nitzschia #a ,nitzschia circumsuta 7,bail47 ,grun4 #aah #b ,nitzschia plana ,wm4 ,sm4 #aag #c ,nitzschia granulata ,grun4 #aaf #d ,nitzschia navicularis 7,brb47 ,grun4 #aaf #e ,nitzschia panduriformis var4 minor ,grun4 #aag #f ,nitzschia apiculata 7,greg47 ,grun4 #aag #g ,nitzschia tabellaria ,grun4 #aai #h ,nitzschia tryblionella ,hantzsch #aaf #aj-aa ,nitzschia bilobata ,wm4 ,sm4 #aah #ab ,nitzschia litoralis var4 delawarensis ,grun4 #aah #ac ,nitzschia acuminata 7,wm4 ,sm47 ,grun4 #aag #ad-be ,nitzschia amphibia ,grun4 #abb #ae ,nitzschia palea 7,kuetz47 ,wm4 ,sm4 #abb #af ,nitzschia fluminensis ,grun4 #abj #ag ,nitzschia obtusa var4 scalpelliformis ,grun4 #aba #ah ,nitzschia linearis 7,ag47 ,wm4 ,sm4 #abb #ai ,nitzschia communis ,rab4 #abb #bj ,nitzschia clausii ,hantzsch4 #aba #ba ,nitzschia epithemioides ,grun4 #aah #bd ,nitzschia vermicularis 7,kuetz47 ,wm4 ,sm4 #abj ,,hantzschia #i ,hantzschia amphioxys 7,ehr47 ,grun4 #aac #bb ,hantzschia marina 7,donk47 ,grun4 #aad #bc ,hantzschia virgata 7,roper7 ,grun4 #aad ,illustration3 ,,plate #cb ,,plate #cc ,,nitzschia #a ,nitzschia longissima 7,brb47 ,ralfs #abc #b ,nitzschia intermedia ,hantzsch #abb #c ,nitzschia spectabilis var4 americana ,grun4 #abb #d-e ,nitzschia sigmatella ,greg4 #aba #f ,nitzschia scalaris 7,ehr47 ,wm4 ,sm4 #aai #g ,nitzschia macilenta ,greg4 #abj #h ,nitzschia insignis ,greg4 #aai #i ,nitzschia vermicularis 7,kuetz47 ,hantzsch #abj #aj ,nitzschia longissima forma parva ,v4 ,h4 #abc #aa ,nitzschia reversa ,wm4 ,sm4 #abc #ab ,nitzschia acicularis 7,kuetz47 ,wm4 ,sm4 #abc #ac-ad ,nitzschia paxillifer 7,o4 ,f4 ,mueller7 ,heib4 #aai ,,homoeocladia #ae ,homoeocladia filiformis ,wm4 ,sm4 #abc ,illustration3 ,,plate #cc ,,plate #cd ,,surirella #a ,surirella striatula ,turpin #abe #b ,surirella anceps ,lewis #abh #c ,surirella intermedia ,lewis #abh #d ,surirella arctissima ,a4 ,s4 #abh #e-f ,surirella delicatissima ,lewis #abh #g ,surirella intermedia ,lewis forma minor8 #abh ,,cymatopleura #h-i ,cymatopleura solea 7,brb47 ,wm4 ,sm4 #abi ,illustration3 ,,plate #cd ,,plate #ce ,,surirella #a ,surirella fastuosa ,ehr4 #abg #b ,surirella biseriata 7,ehr47 ,brb4 #abd #c ,surirella splendida 7,ehr47 ,kuetz4 #abe #d ,surirella crumena ,brb4 #abf #e ,surirella ovalis ,brb4 #abf #f ,surirella tenera ,greg4 #abe #g ,surirella recedens ,a4 ,s4 #abg #h ,surirella linearis ,wm4 ,sm4 #abd #i ,surirella oblonga ,ehr48 #abg #aj ,surirella cruciata ,a4 ,s4 #abg #aa ,surirella gracilis ,grun4 #abg #ab-ac ,surirella amphioxys ,wm4 ,sm4 #abd ,illustration3 ,,plate #ce ,,plate #cf ,,surirella--,continued #a ,surirella elegans ,ehr4 #abe #b ,surirella robusta ,ehr4 #abd #c ,surirella febigerii ,lewis #abh #d ,surirella gemma ,ehr4 #abe #e ,surirella guatimalensis ,ehr4 #abf #f ,surirella panduriformis ,wm4 ,sm4 #abf #g-i ,surirella pinnata ,wm4 ,sm4 #abf #h ,surirella angusta ,kuetz4 #abg ,illustration3 ,,plate #cf ,,plate #cg ,,cymatopleura #a ,cymatopleura elliptica 7,brb47 ,wm4 ,sm4 #abi #b ,cymatopleura elliptica forma spiralis #abi #c-d ,cymatopleura marina ,lewis #abi ,,campylodiscus #e ,campylodiscus hibernicus ,ehr4 #acj #f ,campylodiscus echeneis ,ehr4 #acj ,illustration3 ,,plate #cg ,,plate #ch #a ,amphora gigantea var4 fusca ,a4 ,s4 #fe #b ,meloseira crenulata 7,ehr47 ,kuetz4 #ae #c-d ,licmophora baileyi 7,edw47 ,grun4 #dj #e ,coscinodiscus polyacanthus ,grun4 #bb #f-g ,ditylum intricatum 7,west7 ,grun4 #cj #h ,pyxidicula cruciata ,ehr4 #ai #i ,gyrosigma scalproides 7,rab47 ,cl4 #gf #aj ,coscinodiscus asteromphalus var4 omphalantha 7,ehr47 ,grun4 #bc #aa ,rhabdonema minutum ,kuetz4 #cf #ab ,gyrosigma kuetzingii 7,grun47 ,cl4 #gf #ac ,gyrosigma prolongatum 7,wm4 ,sm47 ,cl4 #gf #ad ,cymbella parva 7,wm4 ,sm47 ,cl4 #fa #ae ,gomphoneis herculaneum 7,ehr47 ,cl4 7zone view7 #gj #af ,cymbella ventricosa ,kuetz4 #fb #ag-ah ,eunotia sp4 7abnormal87 #ed ,illustration3 ,,plate #ch ,,plate #ci #a ,nitzschia spectabilis var4 americana ,grun4 7zone view7 #abb #b ,nitzschia panduriformis ,greg4 #aag #c ,hantzschia amphioxys 7,ehr47 ,grun4 #aac #d ,hantzschia amphioxys var4 major ,grun4 #aad #e ,nitzschia dubia ,wm4 ,sm4 #aah #f ,nitzschia amphioxys ,wm4 ,sm4 #aad #g ,nitzschia compressa 7,bail47 #aaf #h ,nitzschia compressa var4 minor ,h4 ,l4 ,smith #aaf #i ,surirella intermedia ,lewis 7zone view7 #abh #aj ,surirella arctissima ,a4 ,s4 forma minor #abh #aa ,surirella ovalis ,brb4 #abf #ab ,surirella biseriata 7,ehr47 ,brb4 #abd #ac ,nitzschia sigma 7,kuetz47 ,wm4 ,sm4 #aba #ad ,nitzschia obtusa var4 flexella ,h4 ,l4 ,smith #aba #ae ,stauroneis legumen ,ehr4 #hi #af ,nitzschia obtusa ,wm4 ,sm4 #aba ,illustration3 ,,plate #ci ,,plate #dj #a ,caloneis liber 7,wm4 ,sm47 ,cl4 #ha #b ,anomoeoneis sphrophora 7,kuetz47 ,cl4 #hj #c ,nitzschia spathulata ,brb4 #abj #d ,stauroneis 8 abnormal #hi #e ,navicula 8 abnormal #aja #f ,podocystis adriatica ,kuetz4 #abi #g ,nitzschia dissipata 7,kuetz47 ,grun4 #abj #h ,cymbella ventricosa ,kuetz4 7zone view7 #fb #i ,navicula radiosa ,kuetz4 7zone view7 #id #aj ,detail of ,rhabdonema arcuatum 7,lyng47 ,kuetz4 #ce #aa ,diatoma anceps 7,ehr47 ,kirchn4 7containing chromataphores7 #db #ab ,coscinodiscus asteromphalus ,ehr4 7trans4 section1 after ,pelletan7 #bc #ac-ad-ae ,transverse section 7diagram7 of ,pinnularia showing straight1 oblique and grooved raphes #aja #af ,transverse section 7diagram7 of ,biddulphia favus showing inner punctate stratum 7after ,deby7 #ca #ag ,transverse 7ideal7 section of ,surirella #abd #ah-ai ,transverse 7ideal7 section of ,pinnularia1 before and after division #aja #bj ,transverse section of ,nitzschia linearis 7,ag47 ,wm4 ,sm4 #abb #ba ,transverse section 7diagram7 of ,navicula #hi #bb ,transverse section 7diagram7 of ,cymbella #fj #bc ,transverse section 7diagram7 of ,amphora #fe ,illustration3 ,,plate #dj