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Un des symboles sulvants apparaltra sur la dernldre image de cheque microfiche, selon le cas: le symbols — »> signlfie "A SUIVRE", Is symbols V signifie "FIN". Maps, plates, charts, etc., may be filmed at different reduction ratios. Those too large to be entirely Included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames as required. The following diagrams illustrate the method: Les cartes, planches, tableaux, etc., peuvent Atre filmte d des taux Je reduction diffArente. Lorsque le document est trop grand pour Atre reproduit en un seul clichA, 11 est filmA A partir de I'angle sup6rieur gauche, de gauche A droite, et de haut en bas, en prenant le nombre d'images nAcessaire. Les diagrammes sulvants iliustrent la mithode. • 1 ■ 2 3 1 2 3 4 5 6 ^B»- QE O 8Vi 5 X A884 00518 OF THE FOSSIL OSTREIDiE OF NORTH AMERICA; AN'r> A COMPARISON OF THE FOSSIL WITH THE LIVING FORMS. »Y CHARLES A. ^VHITE, M. D., V TH ApPKNWCKa iiY PiioF. ANGELO HEILPBIN anp Mb. JOHN A. HYDEE. 3 INX 18 273 :'ijfer I CONTENTS. Page. Letter cf transmittal 279 Introduction 281 Carboniforons 288 J urossiu 289 Cretaceons 290 Larnmic Group 307 Appendix I.— North American Tertiary Ostroic'ie, by Prof. Augelo Ileilprin ... 309 Eocene 309 Oligocouo . ... 311 Miocene 312 Pliocene 314 Post-Pliocene 315 Appendix II. — A sketch of the life-history of the oyster, by John A. Ryder.. . 317 Explanation of plates 334 976 <.l /. ILLUSTRATIONS. Platr XXX IV. — Cnrl><)ii!roroiii» nnd Jurossio Xij XXXV.— Jiirasaio 337 X.\XVI. — Crctiiceous ;j;)c) XXXVII. — Crotni;coii.s 341 XXX » III.— Crotnceous ;j.|3 XXXIX.— Crctacodim 34;, XL. — C'rctiiccous 347 XLI. — C'rotiicooiis 349 XLII. — (,'ii'tucc'oiiH 351 XLIII.— Cretacoous 353 XL.IV.— (;r«tacooii8 3-,5 XLV.— I'rotnccouH 357 XliVI. — CrutacL'oiis 359 XLVII. — Crntaccons 301 XLVIII.— Crotaccoiig 3(53 XLIX. — Cretaceous 305 L.— Cretaceous 3C,7 LI.— Crotnceous 3(59 LII.— Cretaceous 371 LIII. — Cretaceous , 373 LIV.— Cretacoous 37,'-, LV.— Cretaceous 377 LVI.— Cri'taceous 379 LVII.— Cretaceous 381 LVIII. — Laraniio 3^3 LIX. — Larauiio 380 LX. — Laramie 387 LXI. —Laraniio 389 LXIL— Eoceno 391 LXIII. — Eoceno 393 LXIV.— Eoccuo 395 LXV. — Miocene 397 LXVI.— Miocene 399 LXVII. — Miocene 40I LXVIII.— Miocene 403 LXIX. — Miocene 405 LXX. — Miocene 407 LXXI. — Pliocene 409 ijXXII.— Post-PIioceno 411 LXXIII.— Living Ostroidm 413 LXXIV.— Livinj; Ostreidas 4ir) • LXXV.— Living O.streidio 417 LXXVI.— Living Ostreidii? 419 LXXVIL— Living Ostreida) 42I LXX VIII. — Living Ostreidoj 423 LXXIX. - Living Ostreidaj 405 LXXX. — Living Ostreidaj 437 LXXXL— Living Ostreidaj 429 LXXXII.— Living OstroidiB 431 9tt o / z:ri__frr^ LETTER OF TIlANSMm^AL. Wahiiinoton, June 15, 1883. Sill: I liL'iewitli transmit to you the inunuseript of a IJeview of the Fossil Ostrci(la) of North AincriciJ, whiuli, iit your reqiU'st, I hiivo pre- I)arc(l for your Aumiul Report for 1S,S;{. Tin' work is iicccssarily, to a hirgc extent, a compilation of material that has already been published, hut I have attempted to group that material in such a manner as to convey to the f-eiu-ral reader an outline of the geological histoiy of the oyster family, and tho connection of the extinct with the living forms of oysters. Two important parts of this work have been prepared by Jlr. John A. Eyder and Prof. Angelo Ileilprin, respectively. Mr. Kyder has prepared a concise life-history of the common living oyster of tho Atlantic coast, which he has illustrated by original drawings of his own, and from nm- terial which ho has prepared in connection with tho United States Fish Commission. Professor Ileilpriu has kindly furnished all that portion of the text, which relates to tho Tertiary and post- Pliocene oysters, which material is, in great part, tho result of his special studies of tho Tertiary mol- lusca of tho United States. All this work is, in accordance with your request, addressed to the general reader, rather than to the special student ; but in doing this wo have striven to avoid all scientiflc inaccuracy of statement. Like my contribution to your report for last year, this is a general review of tho subject of which it treats, and not a revision or rectiflcation of the forms which are enumerated and illustrated. Such a rectification is needed, but it must necessarily bo deferred until another time. Tho drawings, with tho exception of tho few that have previously been published, are from the pen of Dr. J. C. McConnell, who also drew tho numerous illustrations for my contribution to your report for last year. Besides tho aid received from Jlessrs. Kyder and Ileilprin, whose work appears under their respective names, I am also indebted to Mr. W. n. Dall, of tho Coast Survey, and Lieut. Francis Winslow, United States Navy, for much information concerning the variation and distribution of tho living oysters of our coasts. «70 -■'-m' 280 m;tti:h ok tkankmittai,. A c(.iiMi.I<.|al.lo iiiiiiiIhm' of 11,,' illiisfiatioiis which arconipiin.v this mciiK.ir havo been diawii fvoiu N|.c('im..im lu'ldiiKinjr t„ th., United Siafi's National iMiis.'iiin, by pcrrnissioii of th<> Dim-tor. Ilo Jias also imt- niitt.'d tlifiiHu of f!...;tn.t.vp(.,s of a portion of those illiistialions whi.-h were iilrca.ly ongravcd and in jiosst'ssion of tlio aniithsonian Institii- tiun. l{i'spc(!tfnll,v Hnbniitted. 4 t Hon. .1. W. I'o\vi;r.L, IHmtor of the United Statea Oeoloyical ttiiriwj/. ('. A. WHITE. rf 1 ., A mm\ OF TIIK roSSIL OSTRFIDyE OF NORTH AMRIMOA; AND A COMI'AKISON OF TliK FOSSIL WITH TIIK LIVIN(! FORMS. Hy v. a. WiitTi:. INTUODIJCTION. IJcciuise of the firoiit value of Mie coinnioii o.vster ns a fiivorito nrticlo of food, iM'iIiaits 110 siihjfct connected with fossil coiicliolofry will bo fouiul to possfss more iiiti-icst to the general reader than that of the Os- treidu', or oyster family. With this siipposilion in view I propose to present on the following,' jta^'es a },'t'"t'nil review of that family as it is rejjresented anion;,' the eolleetioim of fossil remains that have been inado from North Ameriean Htrata. In addition to a ffeneral statement of the subjeet, with illustrations of the fossil forma, I shall {five, lor eomparisoii, n^nires of the lending varieties of the oysters that are now found living uiiofi oiir Atlantie eoast. 1 had intended to illustra.e the living oysters of the Paeilie eoast also, but I found it impraetieable to obtain good siieeiniens of tliem. While much is known concerning the geological history of the oyster family within the area that now constitutes the North Ameriean conti- nent, that history is and will doubtless always remain incomplete. This incompleteness is due mainly to the fact that among the fossil fori-"- it is the sliolls aloiio tl 't are availuble for study and to the fnrthe ' ■:■ that these remains a ) usually few and very olten too imiterfect >o ex- hibit all the characteristics which perfect shells possess. Uesides this, theextrenie variation in the form and other characteristics of the shell of the fossil, as well as the living Ostreidrc, renders their separation into species, and even into genera, a matter of much uncertainly. In the case of most other bivalve shells there is a ciertain precision of symme- try that is constant in every individual, from the earliest to the latest stage of its growth ; but among the Ostreidre, and especially in tho typical genus (htrca, asymmetry of the shell is the invariable rule. To what primary cause this a symmetry among the Ostreidic is due, it is with the present limitation of oiir knowledge, impossible to say ; but it is certainly a characteristic of the whole family, including all it.* genera -ind its fossil as well as living forms. The oyster family belongs to that division of the bivalve mollusca 881 282 FOSSIL OSTREID^ OP NORTH AMERICA. known as the Monomyaria, or tboso whose shells are closed and held together by only one adductor muscle, (a) Other bivalves, such as the common clam, for example, are known as the Dimyaria, and their two shells are closed and held together by two adductor muscles. As a rule, the shells of the Dimyaria are symme- trical, and the individuals of tho various species are constant and regular in their resi)ec;tive shapes and in their ornamentation. It is also to an almost equal degree the rule that the shells of the Monomyaria are asymmetrical, and many of them also exhibit wide indiv'dual variation. There are, however, uoted exceptions to both these rides; such, for ex- ample, as those which are presented by the unsym metrical genera Chama and Miillcria (b) among the Dimyaria, and by the symmetrical Pinna and some species i)t redcn among the Monomyaria. Among the sliells that are familiarly known, those which are most nearly related to tlie Ostreidiu belcug to the genera Anomia, Pcctcn, Spondyhis, AvicuUi, and Pinna. The most unsymmetrical of these be- long to the genera Anomia aiiJ Spondylus, but the Ostreidai exceed all other molluscan shells in asymmetry and extravagant variation. Different authors have, from time to time, proposed separate generic namesforcertainmoreorlessdistinctgroupsofformsamongtheOstrcida;, the greater part of which I regard as not even of subgeneric value. Some autliors,on the other hand, reject all generic distinctions of the family Ostreidaj as it is presented in this memoir, and refer all the species to one and the same genus, the genus Ostrea of Linnaeus. While it is no doubt true that among the fossil Ostreida;, intermediate forms may be selected, which will closely unite all the groups of forms for which sepa- rate generic names have been proposed, it is rega tied as expedient, if not actually necessary, to recognize among them at least two genera besides the genus Ostrea proper, and also one subgenus of the latter. These two genera and the subgenus referred to are recognizable only among the fossil forms, and only the genus Ostrea proper is recog- nized among the Ostreidae now living in North American waters. Fur- thermore, although a considerable number of species of Ostrea have a In Mr. Ryder's article, on following pages, this muscle is described, and is also illus- trated in the fignrcs on Plato LXXIII. Its place of attacbment to tbo sli^ll is a con- spicuous feature of tbo inner surface of each valve, as may bo seen by referring to those figures on tbo accompanying plates wbich represent the inner surface of the shells. 6The genus MUlleria is a strangely modified group of the Uuionidio, or fresh-water clams. It is the shells of this genus, together with those of the related genus Aethena (the former living in South American, and the latter in African rivers), that have been called fresh-water oysters. In their habits of growth and in their forms the shells of these two genera are suprisingly like those of true oysters, but they plainly do not belong to the Of,treidio. MUlleria is said to possess no trace of the anterior adductor muscle in the adult and fixed state, in which respect it still further siuiulates the true oysters. Hut both of the adductor muscles arc present iu the young state and the shells are then also cqnivalve and symmetrical, like those of ordinary Uniones. Like them, the shell of MUlleria is also free in the young state. irnmt.l INTRODUCTORY REMARKkS. 283 + been proposed among the living Ostreidte of North America by different anthors, it is now a serious question whether tliere is really more than one species of oyster now living in the Atlantic waters of North America Those of the west coast of North America are not so well known, but at present three or four species are recognized there by the different anthors who have studied them. The shells of the Ostreidre are inequivalve; that is, the two valves which, like those of all other true bivalve mollusks, are right and left respectively, arc unequal in shape. The molhisk in a very early stage of Its existence becomes attached to a foreign object, and the left valve also becomes attached to that object, leaving the right valve free. Some- times the left valve becomes attached to the foreign object by the greater part of its exterior surface ; but sometimes only by the point of the beak. When the surftico of attachment is large, the shell to a great extent conforms to the surface upon which it is attached; and such shells are necessarily irregular in shape. When the surface of attach- ment is sr ill, the shell is more regular in shape, but in no case are the valves wholly regular. The three genora that are recognized in this memoir, and which have already been relcrred to, are Exoqyra, Gryphwa, and Ostrca, and the subgenus of the latter is Aleclryonia. (a) Exogyra costata, Say, may be taken as the typo of this genus, amlE.forniculata, White, asaii interme- diate form between Exogyra and Oryphwa. The former is represented ou Plates LVI ard LVII, and the latter on Plate LII. The shells of Exogyra are usually more regular in shape than those of any other genus of the Ostreida;, but, as already stated, they are never wholly regular, and they are often much distorted. The left or under valve is always much the deeper, and the right or upper valve is usually flat. The beak of the lo , - ^-aive is always turned strongly to the rear, lb) and It 18 usually more or less spiral. The inconspicuous beak of the upper valve also partakes of this deflected or spiral character. The shells of Exogyra are also, as a rule, more massive than those of any other of the OstreidiB. This is especially true of the lower valve,' which in E. costata and E. ponderosa sometimes reaches an inch and a half in thickness of solid shell substance. The genus Exogyra was a widely differentiated one in the Cretaceous period, within tlie region that now constitutes North America. It was not only represented by a consider- able number of species, but those species embraced a wide variation of form, as may be seen by reference to the figures that represent them on the accompanying plates. The genus Gryphwa is not so well represented in North American strata rtThe specicB which Conrad proposptl to group nnder tho generic name of Grvpht- oUrea I regard as not l.eing even subgenorically distinct from Oitrea proper. See re- marks nndor the head of Oatrea vomer on a following page. iThat is, to the left hand as one looks down upon the cavity of the valve, the hinee border being away from tho person. 1 *, 1 m 284 FOSSIL OSTREID^ OF NORTH AMERICA as Exogyra, and not more than two or three M-ell-»leflncd species are known there. Of these, Gryphaa pUcheri, Mortc u, which is illustrated on Plato XLIX, may be taken as the type. The beak of the lower valve of Oryphaa is usually strongly curved upward nearly in the plane of tho median line, and as a rule not much deflected either to the right or left. The upper valve is like that of Exogyra, flat, or even slightly concave, and its beak inconspicuous and not deflected or 'oilcd. • The American species of Gryphaa are very variable, and it is often diflicult to say in what particulars many of the specimens differ from Ontrea proi)er. The common living oyster of the Atlantic coast, Ostrea virginica, fig- ures of different varieties of which are given on Dates LXXIII to LXXXII, niiiy be taken as typical of tho genus Ostrea proper, altliough several of the fossil species are equally typical of that genus, as may bo seen by reference, for example, to Platos XXXVI and LX. All the living Ostreidre of North America belong to the genus Ostrea proper; all other genera and subgenera of tho family having become extinct. The earliest known species of the family, which are of Carboniferous age, belong also to the typical genus. Exogyra and Grypheca were ap- parently introduced in the Jurassic period, ya) flourished during the Cre- taceous period, when the great oyster tau.iiy culminated ; and both those genera became extinct with the close of the Cretaceous period. But unlike those more differentiated forms just mentioned, Ostrea proper be- gan its existence before the close of Paleozoic time and h ~.s also out- lived both of its kindred but more differentiated genera. The subgenus Alectryonia was introduced with Grypheca and Exogyra, but it survived them only one geological epoch, when it .also became extinct. The remains of the earliest known oysters, as has already been stated, were found in Carboniferous rocks. Professor de Koniuck described Ostrea nobilissima from the Lower Carboniferous of Belgium, .and de Verneuil described 0. materctila from the Permian of Russia. Prof. A. Winchell described 0. patercula from the Lower Carboniferous of Iowa, but no other trace of the family has been discovered in any other rocks of the Carboniferous ago in North America. It is quite clear, however, that the oyster existed through the whole of that a^,e, but it is also quite clear that it was never so abundant in that age as it became in the next, and as it remains to the present day. Fossil oysters are not unknown in the Triassic rocks of Europe, but none have yet been found in North American strata of that age. In the Jurassic strata of this continent tho family is only feebly represented, at least as compared with those of the Cretaceous period. Only one species of Gryphwa and three epecies Oi" Ostrea liave been published a Exogyra is known in Kiirnpcnn Jurassic strata, but in Xortli America no sporiosof that genus is known in any strata earlier tliau tliose of tlio Crefaccons period. Tliero- foro in our studies of tbo Nortli American rocks we regard Exogyra as distinctively characteristic of tho Cretaceous period. WIIITI] INTRODUCTORY REMARKS. 285 from tho Jurassic rocks, oiio of the latter belouging to the subgenus Alcctrijonia. It was in the Cretaceous period, as already mentioned, that the oyster family reached its culmination. At that time not only was there a great abundance of individuals, the remains of which are found in almost all the fossiliforons strata of that period, but there were liviug then a greater number of specific and generic forms than had ever existed before, and greater than have existed since. That is, the Ostreidse not only became generally prevalent and abundant in the marine waters of this part of the earth at tliat time, but the whole family then reached a greater de- gree of vai iition as regards speciQc and generic form and feature than it has ever possessed at any other period. Two facts in tliis connection seem to be not a little remarkable. First the oyster family, which was an inconspicuous one among the mollusca up to the beginning of the Cretaceous period, then assumed, with ap- parent suddenness, a conspicuous position as regards general distribu- tion, numbers of individuals, and wide diffeientiation of species and genera. Second, at the close of the Cretaceous period this differentia- tion was suddenly contracted to even narrower limits than it possessed at the beginning of the r,eriod, although the family still remained a conspicuous one as regards wide distribution, and numbers of individuals. The abundance of oyster-life now existing in North American waters is apparent, when one considers the fact that with the present state of the art of preserving fresh foods, and the facilities for rapid transporta- tion, the oyster has become a common article of food all over our country inland, as well as upon our coasts. It seems certain, however, that the aggregate of oyster life during the Cretaceous period was much greater than it is now. If there had at that time been human beings in ex- istence to whom molluscan food would have been acceptable, the flesh of Exogyra and Gryphwa would, no doubt, have been as palatable as that of the true oyster. Of tho latter, however, there has been no de- ficiency since at least the middle of Mesozoic time ; and their flesh was without doubt, in every way identical with that of living oysters. Althougn the Ostreida;, as a family, culminated in the Cretaceous period, different species of the genus Ostrca proper were abundant in Tertiary time ; that is, in the period immediately following the Creta- ceous. Certain of these species also reached a larger size than that of any which are known to have existed before or since, although some overgrown examples of Ostrea virginka that have been found upon tao '3oast of Maine are reported to be nearly a foot and a half long. Tho so called fresh-water oysters of certain South American and African rivers have already been referred to, and \\, has been shown that they are not true oysters. In tho oyster trade also the terms "salt- water oysters " and " fresh- water oysters " are used. The so-called fresh- water oysters of the dealers are true oysters, but they do not come from waters that are entirely, but only comparativelv fresh. True oysters 286 FOSSIL OSTREID^ OP NORTH AMERICA. cannot live in waters that are not more or less saline. It is a fact, well known to the trade, tbat great destruction of tbe oyster beds is liable to occur at and near tbe mouths of rivers dnring times of high and long- continued freshets in the rivers, by which an unusual quantity of fresh water is passed over them. Lieut. Francis Winslow, U. S. k, of the United States Fish Commission, has furnished me the following figures indicating the range of specific gravity from distilled water to that of the oi)en sea, and also the minimum of that iu which oysters will live. Specillc gravity of opon-sca orator 1. 027 Speeiflc gravity of the fruHlicst waters in which oysters live 1. 010 SpeeKic gravity of distillcil water 1.000 In giving the minimum specific gravity of waters in which oysters will live, Lieutenant Winslow does not mean to say that oysters immediately die when i)laced in fresher waters, but he cites authorities to show that the density of water cannot fall below 1.010 for any pro tracted period without destroying the oysters that may have previously lived in it. It should be remarked that the specific gravity, as above given, is not liecessarily an absolute indication of the proportionate itmount of com- mon salt iu the water indicated, but it is approximately so. There are other substances held iu solution in all sea and baj waters which, no doubt, have much infiuencc upon the molluscan life they contain ; but common salt is so largely iu excess of these, that it is usual to consider that substance alone in such connection. The common living oysters of our coasts are not unfrequently found in oi)en sea waters, but iheir chosen habitat is in the waters of bays and estuaries, which are of less than marine saltness. From the facts here stated we see that there is a very considerable range of saltness of the water iu which oysters will thrive. In the case of the fossil Ostreidte we cannot of course determine the amount of salt the water contained iu which they lived, but there are certain circumstances attending thefossilization of those ancient oysters that tell us with evident approximation the degree of saltness which characterized those waters. Such a judgment of the character of those ancient and departed conditions is based upon our knowledge of the habits of living mollusks in general, and those of the oyster in particular. For example, those oysters which are found living in open sea waters are there associated, not with such mollusks as are its associates in bays and estuaries, but with such as live only in the opensea. If, then, we find, as we often do, fossil oysters imbedded in strata, mingled there with the remains of other mollusks which are closely related to such living forms as are found only in the open sea, we necessarily infer that the oysters in question had an opensea habitat. Again, if we find, as we oiteu do, fossil oyster shelle associated in the same strata with re- mains of molhi!>ks, whose nearest living relatives are found only iu brackish waters, we necessarily infer that those ancient oysters, like their kindred which now exist, were capable of living in brackish as .. WnlTK.) INTRODUCTORY REMARKS. 287 well ns in marine waters. These conclusions are all the more reliable because the other living moUusks referred to are, as a rule, more re- Btricted than oysters are, to certain degrees of ."fvltness of the waters in which tiioy live. Reasoning from such facts as these, it is inferred that the fossil gen- era Exorjijra and Gnjplicca were denizens of the open-sea; tiiat is, of the numerous species of these genera that have been discovered in the rocks of various parts of the world, none, so far as I am aware, have been found associated with such otlier fossil forms as indicate a brackish- water habitat, but all their associates indicate that they were denizens of marine watcr8.(a) The typical forms of Ostrea, on the contrary, while they occur abundantly in strata of diflerent periods, mingled with ra.srino associates, have been found also abundantly associated with other mol- luscan remains that we are compelled to regard as indicating a brackish- water habitat. Therefore we infer that the various species of the genus Ostrea proper have always been capable of living in both marine and brackish waters. The geology of North America furnishes a most remarkable example of an abundance of brackish-watar oysters during one of its geological periods. In that period, now known as the Laramie, and which imme- diately succeeded that in which the uppermost of the marine Cretaceous deposits were made, there existed the most remarkable inland sea Miat the earth has ever known. Its most southern limit, as at present known, is in Mexico, and its most northern in British America. Its fossil mol- luscan fauna shows that, like the existing Caspian, the waters of that sea were not of marine saltuess, but brackish and fresh, or nearly so, in different parts and at different times respectively. Its present known molluscan fauna was illustrated in the report of the director for last year. Among its molluscan remains there is an abundance of oyster shells, which are found at isolated localities throughout that great for- mation. The presence of these shells, occurring as they do in many of the layers, shows that the waters in which they were deposited contained at least enough salt to make them brackish. The absence everywhere of true marine forms shows Ihat the Jjaramie sea was nowhere and at no time of full marine saltuess. In the deposits of all that great intra- continental sea no shells of either Exogyra or Gryphwa, nor any of the subgenus Alectryonia have been discovered. All the remains of the oj'ster fttmily which that great formation has yet furnished belong to the genus 0.itrea proper. These facts are un- derstood to indicate that the first named generic forms, as already in- timated, were not c-.pable of existing in any waters that were not of full marine saltuess, while Ostrea proper throve abundantly in brackish o It is possible that these genera nlso entered the estuaries that existed while 'hey flourished, anil that a knowledge of the fact has escaped ns because estuary deposits of former geological ages are so rarely discovered. It is true, neverthuless, that the OstrcidoB of those genera flourished abundantly in association with moUusks and other animal forms that are characteristic of the open sea. 288 FOSSIL OSTREIDJE OP NORTH AMERICA. as well as mnrino waters. In closing these remarks it is proper to call attention to tlio modern aspect of tlio oysters of the great Laramie sea, as illustrated on Plates LVIII to LXI. In the following treatment of the subject of this memoir I shall follow essentially the same plan that was adopted for the Review of the Non- Marino Fossil MolUisca in the Report of th Director for last year. A rcctilication of all the errors that have been made by different authors in their former publication of the species herein enumerated, is not at- tempted, bnt a part at least of the most obvious errors will be discussed or mentioned. Under the head of each geological period in which any of the Ostreidaj are known to have existed, and under the sub-head- ings respectively of the three recognized genera, all the species that have been proposed by different authors will be given in alphabetical order. The synonymy, at least in part, of each proposed species will be given in connection with its entry. CARBONIFEROUS. It has already been shown to be a well-recognized fact that the oyster began its existence early in the Ca.bouiferous age, and thfit the species had at that early period the distinguishing cl- aracteristics of true Oatrea. It is somewhat remarkable, however, that while the fossil species of the later periods are, as a rule, represented by great numbers of discov( red individuals, a sulBcieut number of examples of the three published species of Carboniferous oysters have not been discovered to give a satisfactory idea of all their respective specilic characteristics. It is practically certain that throughout the Carboniferous age the oyster held a precarious existence, and that it was nowhere and at no timo abundant until Mesozoic time. Onr knowledge of the existence of the oyster in North America dur- ing the Carboniferous age is based upon very slender evidence ; only one species having yet been recognized, and only one example of that species having ever been discovered. Genus Ostrea Linnteus. Oatrea paterculn Winchell. (Plato XXXIV, Figs. 1,2.) The specimen upon which the description of this species was based was obtained from the Kiuderhook Group of the Lower Carboniferous strata at Burlington, Iowa. The description, without illustration, was published by Professor Winchell in the Proceedings of the Academy of Natural Sciences of Philadelphia for 18C5, page 124. The figures of the shell, which are given on Plate XXXIV, are copies of Professor Winchell's unpublished drawings. WIIITI.) JURASSIC OSTREIDiE. 289 JURASSIC. It has already been stated that no examples of tlio Ostreidie have been found in any of the Trinssic strata of North America. This dcfl- cieuey makes a great hiatus in the geological history of the family, between the Lower Carboniferous and Jurassic periods. It is probable, or even practically certain, that members of the oyster family existed in North America during the Triassic period, but no direct evidence of it has yet been obtained. One reason at least for the absence of such evidence is the great paucity of organic remains of all kinds in the Triassic strata of this continent. The slight extent to which the Ostreida) .".-e represented in the Jurassic strata of North America, as compared with .ho Cretaceo'.s strata which overlie them, is perhaps largely duo to a similar cause. That is, the molluscan fauna of the Jurassic period is only feebly repre- sented in North American strata, compared with lihe faunaj of other periods, and of the same period in other parts of the world. Still, con- sidering the geological history of the oyster famuy as a whole, as it is now known, the lack of an abundance of its remains in the American Jurassic strata is probably due largely to the fact that the family had not yet reached its full development. Four species only of the Ostreidce have been found in North American Jurassic strata, but the genus Qrypliaa appears among them, besides typical Ostrea and the subgenus Alectryonia. Genus Ostbea Linnaeus. Ostrea engelmanni Meek. (Plate XXXIV, Figs. 3, 4.) This species was originally published by Mr. Meek in the Proceedings of the Academy of Natural Sciences of Philadelphia for 1860, page 311. It was afterwards republished with woodcut illustrations in Paleontol- ogy of the Upper Missouri, pages 72-74. This is a well-marked species of typical Ostrea; but it is rare, only a few examples of it, mostly imper- fect, having ever been discovered. These were found in what is nr -' the eastern portion of Wyoming Territory, but which was a portion of Nebraska Territory at the time the species was first discovered. Ostrea strigilecula White. (Plate XXXV, Figs. 9, 10, 11.) At almost all localities in Wyoming, Colorado, Utah, and Idaho where the Jurassic rocks are found to be fossiliferous, the shells of a small oys- ter are to be found. They are usually imperfect, both by fracture and also by corrosion or wave-attrition. The oest examples I have seen are 3 INT 19 ^i', 290 FOSSIL OSTREID^ OF NORTH AMEIIICA. described and figured in Reports of United States Explorations and Surveys West of tlio lOOtli Meridian, Vol. IV, p. 103, Plate XIII, Figs. 3, a, b, c, d. This Hliell is sometimes found associated with Oryphaa calceola, var. ncbrascensh; and some of the more capacious examples so far approach that species iu form as to suggest the possibility that 0. atrigilecula may really be a variety of the Oryphaa, with which it is sometimes found associated. Ostrea (Alectryonia) proeumbtna White. (PlatoXXXV, Figs. 6,7,8.) Only a few examples of this species are known, and these are all im- perfect. The best of them are here figured for the first time. They were discovered in Northwestern Colorado, and described in Powell's Report on the Geology of the Uinta Mountains, page 93. Genus Gryph^a. Lamarck. Onjphaa calceola Quenstedt, var. nebrascensia Meek & Hayden. (Plato XXXV, Figs. 1, 2, 3, 4, 5.) This American representative of the European Qrypliaa calceola is not abundant in our Jurassic strata, but it has been found at a considerable number of localities in the great Rocky Mountain region. As already remarked iu connection with Ostrea atrigilecula, the typical forms of tliia species, although they have all the characteristics of Gryphwa, are found associated with intermediate and transitional forms that can, with pro- priety, hardly be separated from the Oatrea. The species in question is f'.ily described by Meek & Hayden in Paleontology of the Upper Mis- souri, pages 7-t-7C. Five woodcut figures of it are given there, which are reproduced on Plate XXXV. The geographical distribution of this form is considerable, examples of it having been found at distant localities in Wyoming and Idaho. The first discovered American specimens, as the name implies, were found in what was then a part of the great Territory of Nebraska; but it is not likely to be found within the limits of the present state of Ne- braska. Although specific limitation among the Ostreida is often so difiicult to determine, I think it would not be unreasonable to regard this form as fully distinct from the Euj^opean one of Quenstedt. CRETACEOUS. The difficulty of discriminating and defining species, even among the living Ostreidae, has already been referred to, and this difficulty is ftir greater iu the case of the fossil forms. This fact will be obvious to any one who scans the following annotated list, and the accompanying illus- WlllTI.J CRETACEOUS. 291 trations of Cretaceous Ostroidre. While a considerable number of tlie names which are given in the following list are shown to be synonyms, or to represent spurious species, it is probable that some of those which are given as representing true and distinct species, ought really to pass into the list of synonyms. Much work needs to be done by a compe- tent student, upon the North American fossil Ostreidaj, especially upon those of the Cretaceous period. The utility of treating the fossil Os- treida) upon the basis of definite specific diagnoses is becoming more and more questionable; and I am convinced that a more general treat- ment of the subject will, in the future, be the more rational. Genus Ostbea. Linnieus. Oatrea americana Deshayes. See Exogyra costata Say, on a following page, with which it is svnonv- mous. ''J Oatrcc anomiwformia Eoemer. Professor Eoemer described this form as a species of Oatrea, in Kreide- bildungen von Texas, page 75, Plate IX, Figs. 7, a, b, c, d, e. The in- terior of Professor Pvcemer's shell is not known; but in external charac- ter it is so closely like certain known forms of Anomia that 1 believe it to belong to that genus. It is, therefore, not considered in this memoir. Oatrea anomioidea Meek. (PlatoXXXIX, Fig8. 4, 5.) Mr. Meek described this form without illustrations in the annual re- port of the United States Geological Survey of the Territories for 1872. It was afterward illustrated by myself in that series of reports for 1878' Plate XI, Figs. 4 and 4 a. Those figures, as well as those which illus- trate the species on Plate XXXIX, are drawn from Mr. Meek's type specimens. Oatrea appreaaa Gabb. (Plato XXXIX, Fig. 9.) The form published by Mr. Gabb under this name is probably identi- cal with his 0. idriaensia. This view is suggested, both by the close similarity of the two forms and the fact that both are reported to come from one and the same formation, the Tejou Group of California. The difference between them is certainly no greater than it is between cer- tain of the varieties of the living Ostrea virginica, as may be seen by referring to the figures on Plates LXVII to LXXXII. Some geologist* and paleontologists, notably Professor Heilprin, contend, and with much apparent reason, that the Tejon Group ought to be referred to the Ter- tiary period and not to the Cretaceous. For the present, however I leave this species with the Cretaceous fauna, where Mr. Gabb placed' it 292 F0881I. OhTKEIDili OF NOUTII AMKUICA. lu tliu rulooiitolotty of CiililoriiiH, Vol. II, pajjo UOS. Tlie illuMtratioii wliicli is ffiveii on Tliito XXXIX \h copied from Imh fiyuro on Phite 34, rif,'. t, of till! volnni i'(|nott'(l. Ontrvn hdla ' lonrad. (Pliilo XXXIX, Fljf. 0.) This Nniall sitt'ciivs was publJHliod by Conrad in tlic report of tlio United States and Mexitran Itoiindary Survey, Vol. I, p. ir»(i, Plato X, Fiys. ■», rt, h. It is probably too closely like tlit form which was named (Mrm clqiantula by Dr. Niswberiy to be regarded an a distinct species. See remarks under the head of that name on a followinf,' paye. Oitrea hiHarinjoMa Shnmard. In his Monograph ie du (lenre Ostren, page GO, Professor Coquand gives the name of "O. heUariKjnmi Shnmard.'' I am not ac(iuainted with the publication of any oyster by that imme. It is probably a misprint or a suppositition for O, hdlipUcata Shumard. Oatrea helUitlicata Slnunanl. (Plato LXXVIII, Figs. 1, y, 3.) Dr. Shumard described this handsome species without figures in the Transactions of the Saint Louis Academy of Science, Vol. I, page fiOS. I afterward ])id)lished a description of it with figures in the Aninud Report pf the United States Geological Survey of the Territories for 1877, p. 270, Plate IV, Figs. 3, a, h; and Plato 8, Figs. 2, a, h. This species appears to be quite constant in its form and general ejiaracters. All the known examples are from Texas. Oatrca blackU \Vhite. (Plato XLV, Fig. 1, and Pluto XLVI, Fig. 2.) This form is of a similar typo with 0. helUplkata, and it is possibly only a variety of that species. Both foims aro from the Cretaceous strata of Texas, but I am not awarr that they have ever been found associated together. 0. hlackii is a !arger and less vontricoao shell and has coarser plications than 0. hfUipUcata. The former was originally described and figured in iuc rroceediugs of tho United States National Museum, Vol. II, page 29b, P.'ate 4, Figs. 1, 2. It was also similarly published in the Annual Iteport of the United States Geological Survey of the Territories for 1878, page II, Plate XIV, Figs. 1, a, h: and Plate XVII, Fig. 4. Ostrea harrandei Coquaud. (Plate XLIV, Figs. 1, 2; Plato XLV, Fig. 2; Plato XLVI, Fig. 1.) This remarkably fiuo species was published in Franco by Professor Coquand iu his Monographic du Genre Ostrea, page 47, Plate XII, Figs. Willie. I CUKTACEOIJS. I- ». lie states ( Iiiit liJH type NpiTiiiieim were olttuiiit-d from Xow JerHoy, but so fur as I am awaic no otlicr cxamiilos of tlio siiccics have uvrr bwii (liscovcml. Tlic, illiistiatioiis of this spfcii's in tliis memoir aro copies of I'rofesMor Cociiiand'rt ligiiros in the work elted. Vol. brief Ontna breiccri Oabb, The iijfure j-ive.i under this name in raloontology of California, V( I, I'late -M, I'lii. 1!»1, is that of an imperfect lower valve, and the bri si.eeillc description on pa|,'o I'Ot of that volume is not more satisfac- tory. The figure apparently rei.resents an oyster closely related to O. coittcilleHMiii, and also to O. wijiminijmmH >^Ieek. Ostrea bryani (iabb. This form is brielly described without illustration in the Proceodinyn of the I'hiladelphiii Academy of Natural Sciences for l.S7(i, page 321. It is reported us conung I'rom the Cretaceous of Nou- .Jersey. OHtim carinata (Lamarck) lioemcr. (I'lutc XLIII, Figs. 1, 2, a, 4.) This species was originally described from the European Cretaceous, but Professor Itoemer discovered it among his Texas collections and published it in K'cidebildungiMi von Texas, i)agc 75, I'late IX, Fig. 5. Professor Co(pia ad regards the Texas form as O.pectinata Lamarck; but although it seems to vary somewhat from O. carinata, I am dis- posed to agree with Professor Hoemer in his determinati».ii. Fig. 1 on Plato X is a coi»y of Professor Koemer's ligure, and Figs. 1>, 3, 4 nr, drawn from a specimen sent from Texas by Mr. George Stolly, of Austiu. Ostrea coalvillenais Meek. (Pluto XXXVI, Figg. 1, 2, 3, 4.) In the reports of the United States (Jeological Survey of the 40th Parallel, Vol. IV, page 140, Plate XV, Figs. 10, a, b, c, Mr. Meek sug- gested this name for an oyster which was obtained from the marine Cretaceous strata at Coalville, Utah. In aspect and details it is closely like 0. mjomimicmk, which, however, comts Irom the Laramie Grouj). (See remarks under Ostrea wyominyensis on a following iiage.) Ostrea confragosa Conrad. Conrad described this species from the Cretaceous strata of Missis- sippi in the Journal of the Academy of Natural Sciences of Philadel- phia, Vol. Ill (n. s.), page 3L'9. On Plate 34, Fig. 4, of that volume ho gave one small figure, which does not possess sullicieut character to give any satisfactory idei. of the species. 294 F088IL OSTREID^ OP NOKTII AMKUI"A, 1 Oitrea congeata Conrnil. (Plato XXXIX, FiKH. 11, la, IX) Perhaps no fossil species of oyster is more common and more widely diMtrihiited in flie Cretuceous striitu of western North Aincrioii thiin O. cont/rHta. It is a small shell; and ahnost nlways the lower valve is broadly attached to some foreign body, notably npon the lurgo shells of Inoceramm. OHtrea convera Say. (Hee anjphaa ve»icularis, on a following page, with which it is re- garded as identical.) Oiitrca cortex Conrad. (Plato XXXVII, FlgD. 3,4.) The form to which Conrad gave this name was found by the United States and Mexican Ho 'ndary Commission at " Dry Creek, Mexico." It is briefly described on page 157 and figured on Plato IX of Vol. I of the report of that commission. Copies of part of those figures uro given on Plate XXXVII, but they are unsatisfactory, both upon zoological and geological grounds. They will serve, however, to add to the fullness of illustration of the fossil Ostreidio. Oatrca crenulata Tuomey. Not the 0. crenulata of Lamarck. (See Oatrca tuomeyi Coquand, a Cretaceous species ; not 0. tuomeyi Conrad, a Tertiary species.) Oatrca crenulimargo Eoemcr. (Plato XLIII, Figs. 8, 9.) Professor Roemer published this form in Kreidebildungen von Texas page 70, Plato IX, Figs. 0, a, b. The O. quadriplicaia, afterward pub' lished by Shumard, is almost certainly identical with this species. Largo collections of specimens show intermediate forms connecting those which were described by Professor Roomer and Dr. Shumard, re- spectively. (See 0. quadriplicata on a following page.) Oatrea crenulimarginata Gabb. (Plato XL, Fig. 2.) This sjtecies is reported from the Cretaceous rocks of Tennessee, and published in the Journal of the Academy of Natural Sciences of Phila- delphia, Vol. IV (n. 8.), Plate 68, Figs. 40, 41. Little is known con- corning its identity. Oatrea cretacea Morton, Owen. (See O.franUini on a following page.) Dr. Morton, in his Synopsis of the Organic Remains of the Creta- ceous Group, page 52, Plate XIX, Fig. 3, published a species under the I. WIIITll CRETACKOirS. 295 Uiiino of Ontrea crctacm, HiippoHiiiK it to Imvo comt! fiwtii rictaccoim Bfrittii in Aliiltiirna. It linx hIiico Ih'cii imcprtiiirK'tl that liio Htratu from vliicli liiH Mp. In tlni Hcconil Kcportof fli.'CJ|.()Ioj;i('al Mnrvi'.v of AikanHas, "IiIi'm VII and VIII, I>r. Ovycn (ijtnml an oyMlcr from ('ictarcons rocl.M of tiiat Hiato wliirli liu rcffiTi'd (o the OMtrea octtm-a of Morton. Withont knowin« that they ••uino fn.m dillV-icnt loinnitlonN, Pioft-wMor Coqiiand regarded tli*>m as loproHcntinK two distinct HpccifH. Thcicfon', in his MonoKiaphiti dii (icnio Ostiva, paj,'»* M, I'lat.- XXIII, FiKs.rt-10, ho miMitiou.-d and ()»,'• nicd Dr. Ovvon's form, and named it Ontrea J'ranlMni. (htrm ilenthuli/cra Conrad. This is another form (ho publication of whieli Ih very unsatisfactory. It was described in the .lonrnal of the Academy of Natural Hciences of Philadelphia, Volumo HI (n. s.), i.aj,'e .iSI. On Plate .'J4 of that vol nme, Fi>;H. I and 8 are fjiven as illuMtiations of the species, but they are not of Huch a character as to givo much aid in simcific idcntitlcation. Mr. Conrad's examples came from the Oretuceous strata of Mississippi. 0$(rea diluviana Linmcus. (Pinto XL, Vig. I ; rittlo XLI, l'ij{g. 1, a.) Some interesting specimens of this form were sent to the Smithsonian Institution some years ago from the Cretaceous rocks of Bell County, Texas. They seem to bo specifically ideutiijal with the long-known O. diluriana of LinnaMis. At least they are so nearly like that Kuropeau species that I do not feel warranted in placing the Toxan form under a separate name. This shell has tlio toothed margin, and to some extent, also, the characteristic marginal outline of Aleotryonia, and it ought per- ha|)s to be ranged under that subgenus. Ostrea elegantula Newberry. (Plato XXXVI, FIgg. 5, 6, 7.^ Prof. J. S. Newberry, in his Geological Heport which accompanies that of Captain Macomb's Exploring Expedition, pago 33, proposed tho name Ostrea elegantula for a small Cretaceous species which ho found abundantly in tho valley of Canadian River, but ho gave neither do scription or figures of it. Professor Newberry has kindly furnished for this article authentic specimens from his original collection, figures of which are given on Plate XXXVI. This form is probably identical with Ostrea bella Conrad, but as I am not quite certain of this, I give both names a place in this list. Professor Nevberry's reference to his form was written before the publication of Conrad's description, but his report was not published until long afterward, in 1876. 29G FOSSIL OSTKKID.E OF XORTII AMERICA. Ostrea exof/yrclla Cuibb. 'Ml. Gahb piihlisliwl (his form witliont figures in the rrocecdiiin-s of , tlie Aciidi-niy of Natiinil Si-iciicos of riiilailelpliiii for 1S7U, i»ii-(.r3L>J, lie reported it from the Crotaccons strata of Georgia, but so far as I am aware it has not since been recognized. Ostrea /(thd fit Jlorton. (See Ontrea hirva Lamarck, on a following page, with which Jlorton's form is regarded as identical ) Ostrva fro nkliiii Voqimml. (I'lat.'XXXIX, Fiss. 1, 3, a) Dr. 1>. D. Owen figured but did not describe this form on Plates YII and VllI of the Second Keport of Hie (ieological Survey of Arkansas, and referred it to the (htrca cretacca of Jlorton. (See "remarks under the head of O. eretacva on a preceding page.) " Chtrca (jnhhnnna Jfeek I'v- Ilayden." This name appears in IMeek's Check List of Xorth American Creta- ceous Fossils, but it is believed that no descrii)tion or illustration of it has ever been jiublisheiL Osirea inornata JFeek. A description and figure of this small form are given by Mr. Jleek in Vol. IX of the United States Geological Survey of the Territories, page IL riato X, Fig. 4. The latter is an unsatisfactory representation of a s])ecies, ami the description fails to convey a dear idea of it. Ostrea idriaemis Gabb. (IMatr XXXIV, Fijjs. 7, 8.) Mr. (".abb described both this form ami 0. apprcssa from the Tejou Group of California. Under the head of the latter nauu^ on a previous page I have suggested that 'joth forms probably belong to one and the same species. 0. idriaoisls is figured by :\Ir. Gabb on I'lates ;?3 and 34 of Vol. II, Paleontology of California, and it is described on page 203 of the same volume. Ostrea (Alectryonia) larni Lamanik. (I'lal.'XLlI.Fi;;.. •.',:!, .1,5, (1,7,8,!).) This variable siu'cies has i)robably a wider geographical distribution than any other Cretaceous (Mrea; and it has been km)wn under more than a dozen si)eeitic names. It is known in various parts of Europe, in Southern India, and in dillercit parts of the United Stu.'es, esi)ecially in Xi w .lersey and Alabama. -Morton in his synopsis jiroposed for three American varieties of this sliell the three specific names/«/c«^«, nastita, and mcscntcrka. •«'■» ,, """"1 CRETACEOUS. 297 Ont>rf 0. diluviana Liu. Ostrea subspatulata Forbes. (Pinto XXXVII, Fig8. 1,2.) The type specimens of this species were obtained by Sir Charles Lyell in \ew Jersey, and published by Forbes, with two wood-cuts, in the (Juarterly Journal of the Geological Society of Loudou, Vol. I, page 01. It has since been somewhat unsatisfactorily identified in the Cre- taceous rocks of the Gulf States, but it has not been anywhere recog- nized as an abuudaut form. Ostrea teoticostata Gabb. (PlatoL.rigs. 4, 5.) Mr. Gabb reported this form as conung from the Cretaceous strata of Tennessee and New Jersey. It is published in the Journal of the Academy of Natural Sciences of Philadelphia, Vol. IV (n. s.), page 403. Two small, unsatisfactory figures of it are given on Plate 08 of that volume. Ostrea torosa Morton. Dr. Morton published a form under this name iu his Synopsis of the Cretaceous Formation of the United St.ites, page 52, Plato X, Fig. 1. It is evidently, as Gabb has pointed out, only a distorted example of Exogyra costata Say. (See remarks under that head on a following page.) Ostrea translucida Meek & Ilayden. See renuirks on a previous page under the head of Ostrea iicUucida. If, as is supposed, this form is ideutical with that which the same au- thors described under the name of 0. pellmida^ the latter name must give place to 0. translucida, because it was preoccupied by Defrauce in 1S21. Ostrea tnomeyi Coquand. Professor Tuomoy obtained this species from the Cretaceous strata of Alabama. It has never been figured, but it was described by him under the name of Ostrea cremilata in the Proceedings of the Academy of Nat- ural Sciences of Philadelphia for 1851, page 171. This name having beeu preoccupied by Lanuirek in ISOl, Professor Coquand, iu his Mou- cgraphie du Genre Ostrea, page 08, gave Professor Tuomey's species the name of 0. tnomeyi. Courad seems to have intended to give the name Ostrea tuomcyi to a i '< h 802 FOSSIL OSTREID^ OF NORTH AMERICA. f. Tertiary species, but be never properly published it. (See Professor Heilprm's remarks under the same head on a following page.) Ostrea uni/ormi^ Meek. (PlatoXLVIII, Figs. 6, 7.) lu the report of Macomb's Exploration, page 124, Plate I, Figs. 2 a h, c, Mr. Meek published a form from New Mexico, which appears to be a well-marked species; but so far only the type specimen is known. Ostrea vellicata Conrad. This species is not satisfactorily known. Conrad described and figured It in the Report of the United States and Mexican Boundary Survey Vol. I page 150, Plate XI, Figs. 2, ,, j. j^ joes not perhaps differ speciQcally from 0. cortex, by the same author, which is figured on the sauie plate. Ostrea vomer Morton. (Plato XLVIII, Figs. 8, 9, 10.) Dr. Morton published this form in his Synopsis of the Cretaceous Formation of the United States, page 54, Plate IX, Fig. 5, under the above name. Mr. Gabb and others have regarded it as identical with the Ostrea lateralis of Nilsson; but it appears to me to as well deserve a separate name as many other American forms which resemble European species. Conrad made it the type of his proposed genus Gryphwostrca. 1 do not, however, regard the characters upon which thatpropcsed genus was based as even subgenerically distinct from those of true Ostrea. Genus Guyph^ea Lamarck. Gnjphaa mucronata Gabb. This name was proposed by Mr. Gabb in Paleontology of California. Vol. II, page 274, for the variety of G. pitcheri to which Conrad had pre- viously given the name G. navia. Grijphwa mutabilis Morton. (See Gryphcca vesiciilaris Lamarck.) Grgphaa navia Conrad. As above stated, Gabb gave the name 0. mucronata to this form. Professor Eoemer figured it on Plate IX of Kreidebildungen von Texas as G. pitchen, and he was doubtless right, as G. pitcheri is a very variable species, and G. navia is regarded as only a variety. Gnjphaa pitclieri Morton. (Plato XLIX, Figs. 1,2,3,4,5,6.) This is perhaps one of the most widely distributed and most variable species among the Ostreid* of North America. It was originally dis- ^ WIIITB.] CRETACEOUS. 303 covered in the Cretaceous strata of New Jersey, and published by Dr. Mortou in his Synopsis of the Cretaceous Formation of the United States. It I js since been recognized in widely separated localities in the United States and Mexico. Some of the varieties lose the promi- nence of the beak of the lower valve, and approach an ordinary oyster in ai)pcarauce. A variety of this species, somewhat common in Texas, is narrower than the typical form and has a more produced beak to the lower valve. Conrad gave this form the name of G. navia, as already mentioned. Figures of it are given on Plate XLIX. Oryphaa thirsw Gabb. Mr. Gabb described this as a Cretaceous species, but according to Professor Heilprin it is found in true Tertiary strata. He regards it as not generically distinct from the Ostrea, and it will be found on a following page among the Eocene species under the name of Ostrea thirsw. Oryphaa vesicularia Lamarck. (Plate XLVIII, Figs. 1,2,3,4,5.) The species which is arranged under this name is a somewhat varia- ble one. Dr. Mortou published certain specimens of it under the name of Ostrea mutabilis, and Say published others as Ostrea convexa. These American forms are now generally regarded as specifically identical with the long-known European species Qryyhwa vesicularis of Lamarck. It is found in the Cretaceous rocks of the Atlantic and Gulf States. Qrtjphwa vomer Morton. Dr. Morton described this species as a Oryphaa, but I regard it as not generically distinct from true Ostrea. (See remarks under O^^trca vomer on a preceding page.) Genus Exogyba Say. Exogyra arietina Eoemer. (Plate LVI, Figs. 3, 4, 5.) This species is quite a common one in the Cretaceous rocks of Texas and theadjacent parts of Mexico. It is generally known under the above name, which was published in Kreidebildungen von Texas, page OS, Plato VIII, Figs. 10, a, b, c, d, e, but it possibly ought to be called Exogyra laxa Say. In 182G Mr. Say described a shell under the name of Delphinula laxa which, from its resemblance to certain si)ecimens of E arietina, and my lack of knowledge of any other species to which it may belong, I believe to have been a specimen of the larger valve of this Exogyra. If I am correct in this supposition, Say's specimen was that of a fossd nistead of a recent shell, and an Exogyra instead of a Delphinula. Say 8 very brief and unsatisfactory description of D. laxa may be found e^-^ss'^-tS^^^^sai^^^^^wrsi*- ^mm>^^^ 304 FOSSIL OSTREIDiE OF NOUTII AMERICA. i fi I ou page 150 of Biiine.v'H edition of Say's wiitiuga and Mrs. Say's excel- lent ligures of it on I'hitc 7 of that volume. Conrad puhlislied this species under the uanic o{ Exogyra caprina in the Journal of the ^Vcadeuiy of Natural Sciences of Philadelphia, Vol. II (n. N.), page 2T^, I'late XXIV, Figs. 3, 4. Koenier's name must remain, however, because it was previously published, unless tlio name Exogrjra Utxa Say shall be used. Exogyra uquila Goldfuss. (ridtoLIII, Figs. 1, a.) The 8i)eeimena which are here recognized as belonging to the Exogyra aqitila of (Joldfuss were sent to tlie Smithsonian Institution some years ago by Mr. D. A. Walker, from Hell County, Texas. [Jpon comparing them with the figures given by Goldfuss in his Petrefacta C.ermaniro, page ;{(J, Plate 87, 1'ig. .{, no features appear to me upon which a specific difference can be based. I am not aware tliat this species has before been recognized in Ameri(!an strata, but various authors have reported it from different i)arts of Europe and from both Northern and Southern Africa. Exogyra columbcUa Meek. (Plato LV, Figs. 5, (i.) This small species of Exogyra has hitherto been found only in Southern Utah and the adjacent parts of New ^Mexico, where it is sometimes found assocmted with E. lariiiscula Koemer, which species it resembles in size. Itwas published by myself in the reports of United States Explorations and Surveys west of the 100th Meridian, Vol. IV, page 174, Plate XVII, Figs. 3, a, h, e,(l. I there regarded it as a small variety of E. cantata, and gave it the variety name of fltminis. In the same year Mr. Meek published this form under the name of E. columbella, in the Report of Macomb's Exploration, page 124, Plate I, Figs. 3, «, 6, c, d. Exogyra costatc Ssiy. (Pl.ito LVI, Figs. 1, 2; Plate LVII, Figs. 1, 2.) This is one of the most common and characteristic as it is one of the largest species of Exogyra that are found in the Cretaceous rocks of the United States. It is especially characteristic of certain strata in the Atlantic and Gulf States, and also in Mexico. It is usually quite con- stant in its form and in the costate character of its surface, but in the latter respect it is sometimes variable. Indeed, some authors regard Exogyra pondcrosa Eoemer as only a variety of E. costata, dilfering only in the obsolescence of its costre. This feature is so constantly present in the one form and absent in the other that I prefer to regard them as representing distinct species. i W^^ WIIITI.) CRETACEOUS. 8m ., I . Exogym Jimbriafa CouraiL Thi8 proposed species is really nnwortliy of notice, because its original description was based upon only a single npjier valve, which is i)robably that of a small example of Exogyra ponderosa. Conrad i)nblished it in the Report of the United States and Mexican Moiindary Survey, Vol. I, page 154, Plate VII, Figs. L', a, b. Adding still further to uniieces.sary synonymy, the name is, by typographiiial error, given as E.foluwca on Plite 7, Vol. I of the United States and Mexican Houndary Survey. Furthermore, Coquaiid, in his Mcmographie du (lenre Ostrea, i)age 00, jiroposed to change Conrad's supposititious name to 0. Habjiiiibriata. Exof/yra /orHiciiIafa White. v-liiti^ ur, riKH. 1,2.) Tlie gnidation of the genus Gryphwa, which has before been referred to, is exeinpiilied by this species, wliich might with equal proimety be referred to cither genus. The jHincipal distinguishing cliaracteiistic of Exoyyra I have taken to be the lateral deflection aiul greater or less curvature 01 the beak of the lower valve. The full develoinnent of this feature is shown in sucli forms as E. costala and E. Iwi-iimcula, and the minimum, in the species heading this i)aragraph. So far as I am aware Exogyra forniculata has been found only in Texas and the adjacent parts of Mexico. It has often been coniounded with the variety of Grypluea pitcher i to which Conraiiiiiiiii d'Oiliii^ny. Conrad, in tlie Kepoit ot' tlie United States and Mexican Ilomidiiry Survey, relcncd certain spcciincns to tliis species tliat are Npecilleally identical willi tlie loriii tliat Prolessor I^eiiicr dcsciiltcd under tlie nanio of i:.ni;ij/ni tvjatiii. (See icniaiks under tliat liead in a loilowiiij; para- Kiapli.) I( is a soiiiewliat coiniiion lonii in the Cretaceous of Texas and tlie adjacent jiarts of .Mexico. L\riifii/r(t pJivdIa raniarck. It isdoiihlfnl wlietlier tliis species exists in North American rocks. Certain antliors liavo placed siieciinens nnder this name wliieh I helievo to belon;; to the 11. icvauii of Ktemer. (See remarks nnder that head in a followiii;,' paia;;rapli.) Exofiyra ponderoaa Rcumor. (I'latL- I,, I'iKs. \,->, :i.) This massive form is eommon in certain Ceretaceoua strata of the States which border the Cnlf of .Mexico; rxtendinj;- westward into the Uepnblic of Mexico. It was tirst pnblislied by KVemer in Kreidebildniifr V)ii Texas, pajre 71, IMate IX, Fifjs. 2, a, h. A.s before remarked, it has by some authors been re^jardcd as not specitically ditl'erent Irom E. cos- tatii Say. Tlie two forms are certainly closely similar, but their surface characters are njjparently constant in their did'erence, even when they are found associated in the same stratum. The lower valve of this species is very massive in old examples, sometimes reaching: nearly two inches in thickness of .solid shell substance. Exogyra parasitica Gabb. (Pl.itoI.V, Fif,'s. ;!,4.) Mr. Gabb jiublished this form in Paleontology of California, Vol, I, l)a^'e 2()5, Plates 2(! and M. It is interesting^ because of the very slifjht rei)resentatioii that E.vo()\jra has in the Cretaceous strata of the Pucilic coast. Exogj/ra tcxana IJa'-iner. (IM.iio 1,1, 1'igH. i,'.',;i,.i,,'-).) Professor Hcenier published this specie."? in Kreidebildung von Texas, pajre ()!», Plate X, Figs. \,a, b, c, d, c. It is not unfrequcntl.v found in cer- tain Cretaceous strata in Texas and the adjacent parts of Mexico. It has been by various authors referred to £. ylicata Luiuurck, aud E. Matherouiana d'Orbigny. f *"'T«1 CRKTACEOUS, 307 I'jcogyra icalkeri White. (I'lutr LIV, TiK^. I, 'J.) This JH a hunt', iioimiuchnimI form, which coiiioh from tht( Crctaeooua Ktratii of Texas. It was ])uiilisli*Ml in ilin Annual lU'port of liio Unitotl Htatos (ii'ohj;,Mcal Hurvcy of tht< Tcrritorit-s for 1877, i)aj,'o li7S, I'hito I, FiKs. 1, a, h. I'hogi/ra winchclU Wliite. (IMiiti! I,V, I'ijrs. n,7; riato I,VI, ri),'H. 1,-J.) Th(^ form whiiiii is most nearly related to this speeit^s is tlic hi hatio- toitlrii of Sowerliy, hut it is more elou^j.ite than that shell, an*l the front Hithi is more abruptly elevated. It is probable that this Anieriean form mit;ht be with jiiopriety ree,o^iii/ed as a variety of the ICuropean L\ haliotoiilni, but I prefer at present to refjard it as distinet. I have re(;oi;ni/ed iho last-named speeies anions souu! Cretaceous fossils from Hrazil, and they seem to bo sulUeienlly distinet from E. winchvlli. It is only in the Cretaceous strata of the (lulf States that IJ. winclirlli is yet known. It was iiublished in the l'ro(!eedings of the United States National Museum, Vol. II, jjajje li'Jt, i'lates II and III; and also in the Annual IJeport of the United States CJeoloj,'ical Survey of the Territories for 1878, page VJ, Plate XIII, Fijjs. J, a, b,c,d. ' LARAMIE GROUP. The preat brackish water formation of Western North America, which is known as the Laramie Group, has already been referred to. In this great formation no true marine fossil remains have been found, but oy.ster .shells are not unfrequontly found in its strata, and in some places they ar(>, abundant. Among these no less than live species have been proposed by difl'crent authors, but later collections show such gradations of form that I have not been able to recognize more than two species among them, and it is pro'jable that there is reiilly only one species in the whole formation. These oyster remains of the Laramie Group not only belong to the typical genus Oxtrca, but the most abundant of the two recognized species is very closely \i\n'. the living Oxlrca vinjinica. This species is quite constant in its lyjiical form, even at points more than a thousand miles distant from, each other, and the extent of its geographical ilistri- bution seems to have been quite e(pial to that of the living O. vinjinioa. Ostrea glabra Jleek & Ilayden. (Plates LVIII, MX, LX, LXI.) This widely distributed sp cies was first published under the above name iu the Proceedings of the Academy of Natural Sciences of Phil- 308 K0881L OSTRKIDiK OK NORTH AMKRICA. iHli'lpliia, for 1857, pnKO 13(1. The typo Hiu'cinicnH were obtained from Mm Upper MisHoiirl Kivcr n-Kioii j iiiid the BinootliiiCHM wliifli HU|;{;c'Htcil tlu'ir Np«'cill«! iiaiiic was not natural, but duo to attrition or corro8ion. FiKiin-M of out' of Ihcso t.vpo NpocinicnN nro tiwvw on plato LVIII. lu Jlic Animal Itcportof llio UniH-d HtatoH (!coloj;lcal Hurvry of the Terri- tories, lor \H-,2, \>i\m> TtOH, Mr. Meeli deMcrihed a form I'rom Hoiitiiern W.vominy; niidcr the name of Onlnn iri/ominiimiH, ll;,MireH of wliicli are jjiven on I'lates liX and LXI. In tin- .samewerieHof reports, the volume for IST.'t, pii^e 177, he deserii)ed anotlier form from tlie same loeality under Ihe name of (K (iiriinliliH. Fij;. o, ou Plate MX, Is drawn fnmi his type speelmon. In I'dwell's Keporf on the (ieoIo;,'y of the rnlta Mountains, pa^e lili, I ile.Mrilied another form from Honthern U'yomin;,' under Ihe mime of (). hiHiriiriK. Fi^'ures of tlie type speelmen are jjiveii m Plate lAX, Now, all iheM- formM, as before mentioned, I regard as belonniiiK toono an. lingiin-ciitiin l,m. Il>., puno 98, O. pincnnii t.cii. II)., |m){« 1)8, *f>. Ktmllunnta Lcii. II),, pajfo ) is i)robably the 0. carol inoinis Conrad, a form very closely allietl to 0. c»mj»r.s').//-()sO'((. Ontrot cretacvit Morton. This sjiecie-s, de.scribed by IMorton in the Synopsis of the Orjranie lUv mains of the Cretaeeons (Ironp, pa^e 52, Plate XIX, Fifj. ,'{, is fonnd in Sonth Carolina and Alabama (?). It is {jiven as lOoceneon the anthority of (iabb (Proceedii-^'s of the Phdadelphia Academy of Sciences for 1801, l)ase;{2S; " IMolhi.sca of the Cretaceou.s Formation," page loi!) and is not inclmled in Conrad's Check List. Ostrea divurifuta Lea. (Plato I.XIV, Fig. 1.) This was published by Lea amonjihis collections from Alabama in his Contribution to Geology, jjage !»1, Plate III, Fig. 70. SVN.— O. fiubiUula\ Laimiiik. Tn the Proceedings of the National Institute (1841-'C, ])age l!).'i), as well as siibsecinently (American Journal of Conchology, 1, jiage 15), Conrad nniiesi;,itingly refers this sjiecies to his O. ncllwformis — a view which appears to me to be decidedly erroneous. Although the two species <'losely resemble each other in the young stage, they may, nevertheless, on close ins])ection, be readily distinguished from each other. The dis- tinguishing characters between O. diroricata and O. /(ilcifoniiis Conrad (American Journal of Conchology, i, jiage 140) are not so easily made oi't. and I must confess my inability thus far to discover what they are. The 0. (liraricata certainly agrees very closely with the ligures and de- scrii)tion of Lamarck's O. .//((/><■//(//«, to which species it is in fact uidiesi- tatiiigly referre, p. 41). The last is a very variable and one of the most widely dispersed of fossil oysters, its range extending from Alabama (l)eshayes; and iTOrbigny, Prodrome de Paleontologie, 11, page .'!!)4) to (hitch, in India, and Cairo, in I'lgypt (I)esiiayes, Aniiii. sans Verlebr. liassin de Paris, 11, jyage 121.) OatftM crrrsit ^Meiiville sj). (I'lalr LXIV, Fi-s. 5, ti, 7, 8.> A fossil of the French Eocene (l)eshayes, Anim. sans VertM)r. I>as- sin de Paris, II, i)i'ge !)lt, Plate 84, Figs. 5-8), identified in the I'joceuo of Maryland and ^!ississii)i)i. Sy.\. — Griiphostrca vrrraa Coiirail. Siiiillisotiian Chock List. t IIEII.IMIIN I TKRTIARY. 311 #>< Ostri'd /iilvi/dniiis Coiinid. ' AiiRMicaii .lomiiiil ol' Coiicliolopy, I, pago, 110. From Mississippi. ^''YS.—O. iliriiriciihit I. Oil. Sii|irii. (htrcd murtoiiii ('r.ihh. I'loiii Aiiihiiiiia and Soiitli Carolina, rrocot'din^is of flic Academy of Natuial Scicnci's of IMiiladcIpiiia i'or 1801, jjajio 3-!). .Syx.- I). iHiinlii (iiiir.s) Mcirlon. Symipsis Or;;;iiiic Ufiiiiiins, piiiji' ."il. O.strra stihv/onuis Conrad. (Plilo I.XII, Fi^M. I,--'; ri:it(> I,Xll[,l"in. I.) I'roiii tlio Eoi'ono of Alabama, South Carolina, and Virfjinia. Piib- lislicd by Conrad in bis I'^ossil Slu'lls of the Tcrliary Formation, Hist edition, pa;.o '21. Syn. — (>. nii/inno Conrad; siiiiu' wdiU sini] piifjc. O.strcu tliirnw Gabb. (riatc I.XIII, Tins. .1, .s, i;.) Tlii.s form was ]>tdilisli('d by Gabb as a ('retaceous si)i'(',';s in tlio Pro- cecdinfjs of the I'liila(k'lpliia Academy of Sciences for 1801, i)aj;«! MO; but it is now known fliat the strata I'rom which it comesareof Foccneafjro. G;ibb referred it to the <;enus (Iii/i'Ikvi:, but, althoufih it api)roaclies 0. rcxivularis in Ibrm, I am disposed to place it under true Ostrcn. Onlrrii tridonalis Conrad. I'roceedins's of the I'hiladelpiiia Academy of Natural Si-iences, VIT, pajio L'iV,). From ^Mississippi. f Ostrcd tuomnji Conrad. This nanu' is jjiven by ('onrad, Xo. 0!).') of the Smith.sonian Check List, as citminj;' I'roin .Mississippi. I have seen no specinu'ns of this species, nor have 1 been able to discover where it i.s descrihed. Ostvca (]rnrglnnn Com ad. Ot.KiOCI'.NK. Ostrca <]rnrgiann Coniad. Conrad imblishcd this speciis in the Journal of the I'iiiladelpliia .Vcadeiny of Natural Sciences, \'ll, ]>. l.")0. Il is ic|>orl('d as coiium^; from Georgia, .South Carolina, Mississippi, and Lower California (?1. There is a larjic oyster in I he ('(illc<-t ion of I he .\cademy from Lower Cal- fr There is a larjic oyster in the c(illc<-i ilbrnia, marked ().<]t'or(iiuiiii ; it cerlainly L;reatly resembles that species, but its characters are to soni(M'.\teiit obliterated, which prcviMits abso- '■"' :i ■■•:': ■.:-,_ [ slioidd liot lic surprised if, on comparison with lute idcntilicalioi 1 o ute idcntilicaliou. 1 shoidd not be surprised if, on comparison wi l. (lairiiiaiKi will be found to be only a varie if 0. frtinsissiinit I inarcl: (Miocene of a vciy laifje portion of I'Inropt variety pe) 312 FOSSIL OSTKEID^ OF NORTH AMERICA. The reseniblnDce of the figures of that species is very great; and if the American oyster does not assume quite the ponderous proportions of its European cousin, the circumstance may be due to local causes, such as crowding. Conrad states that this species reaches a length of 22 inches. Ostrea vicksburgensis Conrad : (Plato LXIII, Figs. 2, 3 ) This species is from the well-known locality of Vicksburg, Miss. It was published in the Journal of the Philadelphia Aciulemy of Natural Sciences, Vol. I (u. s.), page 126. MIOCENE. Ostrea attcoodi Gabb. (Plato LXVIII. Figs. 4, 5.) This species is said to be either Miocene or Pliocene. It was pub- li.shed in the Paleontology of Calil'ornia, II, pages 33, 34 ; Plato X Figs. 58, 58n; and Plate XI, Fig. 58b. Ostrea borealis Lamarck. This fossil form is id»>ntifii'd with a recent species.* It is published in Laman-k's Aniiiiaux sans Vertebres, second edition VII, page L'20. There are in the Academy's collections lour specimens of an oyster niiirked "St. Charles, .Maryland, Cope" which answer perfectly to IjaiiiarcU's sjiecies. It is probably Miocene. Ostrea cvii.lracta Conrad. (Plato LXIX, Figs. 1, •_>.) This species is rejiortcd by Conrad as coming from Oyster Point, Mexico, and as probably Pliocene. It is published in the Keport of the United States and Mexican Boundary Survey, I, page IGO, having been previously piiblislied in the Proceedings of the Philadelphia Academy of Natural Sciences, V',!, page 2«9. Ostrea dispdrilis Conrad. (Pliitf LXVI, Fig.s. 1, 2.) From Vir;;inia and South Carolina. Conrad's publication of the species is in liis Fo.ssils of the Medial Tertiary rorniation, i)ago i^JJ, Plate lid. Syn. — 0. rai-eii,liit»a Tiuiiiicy & Holmes, in I'liocoiU' Fiissil.s, page 21. The dift'erences wliich were pointed out by Tuomey & Holmes as separating 0. roveneliana in.m 0. disparilis cannot be said to exist. * See Plate LXXX lor receut specimens. m •4 ! imLPuni.] TERTIARY. 1h y K Oatrea panzana Conrad. Conrad publisLed this form as coming from California in the Pacific Eailroad Reports, VII, p. 193. He regarded it as possibly the mature shell of 0. subjecta. I hare seen no specimens of this species; nor is ii determinable from Conrad's figures. Gabb was unable to recognize it among the collections of the California Survey. Oatrea percrasm Conrad. (Plate LXVII, Fig. 3.) This Miocene form has hitherto been recognized only in New Jersey. Conrad published it in his Fossils of the Medial Tertiary Formation, page 50, Plate 25, Fig. 1. Oslrea sculpturata Conrad. (Plato LXX, Fig. 2.) From Virginia. Published in Fossils of the Medial Tertiary Forma- tion, page 50, Plate XXV, Fig. 3. Syn.— 0. rir(iitiiana vnr. Conrad (non Gmeliii): Fossils of the Tertiary Forma- tions, lirst edition, p. 28. Ostrca subfukata Conrad. (Plate LXVIII, Figs. 1, 2, :i.) From Virgiiiiii. Publisiied by Conrad in his Fossils of the Medial Tertiary F rniation, page 50, Plate XXV, Fig. 2. Ostrea suhjccta Conrad. Reported as coming Irom California, and published in the Pacific Railroad Reports, VI 1, i)age 193. I have seen no specimens of this species, nor is it determinable from Conrad's figure. Gabb was un. able to recognize the form among any of the collections of the California Survey. Oaiera fayhirinDa Gabb. (I'liilo LXVII, Fig. 1, 2.) From California. Published in Paleontology of California, II, p. 34, Plate 12, Figs. ()0, C0((. Ostrc'i titan Conrad. Coiinwl i)ublisiied this large oy,ster in the Proceedings of the Pliila- delphia Academy of Natural Sciences, VI, i)age 199; the Journal of the .same (n. s.), IV. i)age 300, ami the Pacific Railroad l{ei)orts, VI, page 72. Tills is to my knowledge tiie most ponderous o,\ster found in tlu> United States. In (•ertain of its forms it so closely resembles the 0. f/ingensis of Sehlotheim as to be but barely separable from tiie common European species. Like it, it also affects the long, the curved, and the 8e()oi)e(l forms, the spare between the va!ves in the last case being very 314 FOSSIL OSTRF.IDiE OK NOinil AMF.RiCA. ciipacions. All tiiicesnf radiarc idications, if it oviT iiossesscd any siuiii ornaiiit'iitatioii, liavo (lisappcarcd in tiu' spcciiiifiis lict'oie inc. The loiifi fonus may Ik; ivadily (listinjjiiislicd Crom tiic O. crdssixulnia I,a- niarck by tlio comparative siiortiicss of tlic nmbonal rcyioii. Osirea rchfinua ('oiirad. ^I'hilii 1,.\X, Ti-. 1.) Tiiis species was colii-ctcd in Ai'izona by the United States and Mexi oiindary (Jomniission, aTid ])ublislied in Vol. I, Part II, pa^e Hit). It is stated to be probably Miocene. (htrcd virghiica Gmelin ( = 0. vmi'minnn I.amarck). Syx. — 0. mauricennin Gabb ; .iDiinial of I ho riiiladelphiii Acadi iiiy of Natural .Soicnccs, IV (n. h.), \>'d'^c liTli. The O. maiiricensis does not appear to dill'er materially, if it differs at all, from the lon,sj fcrins of 0. virginicn. This species has been found fossil in New Jersey, JIaryland, Virjjinia, North Carolina, and South Carolina. A fossil form of the I'aluns of Touraiiie. and in the vicinity of Bor- deaux, is rccofinized as identical with the common living oyh er of our Atlantic coast — 0. virgimca {"Sldm. 8oc. Gcol. dc France, II). PLIOCENE. Ostrca atwoodi Gabb. This species has already been noticed under the head of Miocene. Gabb was undecided wiiether to refer it to .Miocene or IMioceuo age. Chtrea botirr/eoisil licmond. (Plate I,XXI, I'if^. 1.) rul)lished in the l'rrobably .Miocene (as prob ably from the .same deposit which contained (>. vcxiii'rtina),i\U{\ is given as sncli in MeeU's Miocene I .st ; but in the appended "Notes and Vj\- lilanations"' (page I'd) it is .'^tated that "(.'onrad now thinks his Oxlvrit li ccr 111(1 II iii ])robably a Cri'taceous s])ecics." Carrizo (Jreeli, Colorado Desert, when; it was found, is Plioceiu', according to Gabb; and the O.harmaiini is accordingly given as a Pliocene species in Paleontology of California, 1 1, j). 107. i IIKII.l'lllN.I TEUTIARY.— POST-TKRTIARY. 315 Oistrea vcspertina Conriul. (I'latuLXXI, I'iss. y, ;i, 1.) This form was published in the Jounial of tlic PliiliKU'lpliiii Acailciny of Natural Scicnucs, II (ii. s.), page 300; United States and Mexican Boundary Survey, I, page 100; and the Pacific llailroad Keports, V, l)age M.-,. It is closely related to both O. suhftikata and 0. scalptufnta, and Ih ])ossil)ly only a variety of one or the other of these species. It va,s originally described as Miocene, but the locality where it was obtained by Conrad, Oarrizo Greek, Colorado IJesert, is considered Pliocene by Gabb. POST-PLIOCENE. Ostna conckaphila Carpenter. Tliis name is given as that of a California shell in the Catalogue of Mazatlan Shells in the British Museum (1857), page IGl ; but not figured. Theie are nine specimens of an oyster in the coUectioM of the Phila- delphia Academy, marked " 0. conchaphila, Cpr.," from the post-Plio- cene of San Diego and False Bay; but whose determination the same may be I am unable to state. The 0. concliaphila, as far as I know, is not stated to be fossil bj' any i)aleoutologist. Some of the above speci- mens are undistinguishable from lecent speciuh'us marked O. lurida Ci)i'., also in the Academy collection, wlijcli is stated to be fossil by Newberry and Gabb. It therefore ai)pt'ars to me that the specimens marked 0. concliaphila are more likely to be 0. lurida, although their characters do not exactly agree with Cari)enter's description of the lattei- s);ecies. Ontreafiindata (Say?) F. S. IJolmes. Post-Pliocene Fossils of South Carolina, ]). 11. I have seeji no speci- mens of this si)ecies. Out ten (jallust Valent iennes. Figured without description, Voyage de la \'(muis ; Atlas de Zocilogie, Plate 21. California. A lecent .species. SYN'. — <). cfmiHiiifit (.ialMi; riilfiiiitiildgy (iT Ciilirurnia, II, jiago '\'i. Ct'rros ImIuikI.s. As stated by Gabb, Paleontology of California, II, |)age 100, O. cer- roscnsis is in all probability iilenlical with 0. gallus, which, as figured, is about twice the .size of the California tbssil. A fossil from the late Tertiary of Peru, received from Professor Paimondi, which is consid- ered by Gabb as the e(iuivaleiit of his (). crrroaensis, is about the size of the living 8i)ecies, and undittinguishable from it. i mmm 316 FOSSIL OSTREID^ OF NORTH AMERICA. Ostrea lurida Carpenter. (Plate LXXII, Figs. 2, 3.) This living species is mentioned as fossil in tbo Pliocene of California in Mollusks of Western North America (Smithsonian Miscellaneous Collections, 252), page 305. It is not figured in that work. Syn.— O. ediilh Cooper (uou Lin.) fide Curiieiiter, loc. ci<., page 85, — Gabli, Paleontology of Ciiliforuia, II, i)ago 106. From Benicia. Fossil at San Pablo, according to Dr. Newberry (teste Carpenter, loc. cit., page 300). Ostrea veatchii Gabb. (Plate LXXII, Kig. 1.) This is another California species published by Gabb in Paleontology of California, II, pages 34, 60. .J. 1 ... APPENDIX II. A SKETCH OF THE LIFE-HISTORY OF THE OYSTER. By John A. Eydeb. TIic oyster always preseuts a definite right and left side; a dorsal or upper, and a ventral or lower part of tbe body, and an anterior or head end to which the hinder extremity is opposed. Thus it will be seen that it resembles greatly many eomnion animals, not only in the respects already noted, but also in that the right and left halves of the soft ])art8 are, with the excei)tion of the alimentary canal, repetitions of each other, so that, as in man and the higher animals, there is a|)parent in the oys- ter that likeness of oi)i)osite sides of the body which has been termed bilateral symmetry. While this symmetry of the soft parts is so evi- dent, it is less palpable when we compare together the two valves or shells which inclose and protect tlie animal. In the natural beds the left valve is usually undermost or inclined to be so, but in the (srowded banks the shells, as growth proceeds, tend to assume a vertical i)osition. The left valve is also more concave or hollowed out internally than the right one, which is often very nearly flat. In the European oyster tOntrea editlis) both valves are much flatter than in the American and Portuguese (O.virginka and 0. angulata); in the former the muscular impressions are also very nearly pyriform aud colorless, while in the two latter they are usually more nearly kidney-shaped and deep purple in color. The average size of the American and Portuguese is al o much greater than that of the common European species, and both the former grow much more rapidly than the latter. Fig. 1, Plate LXXIII, represents an American oyjter which has had the right valve and the most of the mantle of the right side removed, in order to show the soft parts in position as they lie on the left one. The head end of the animal lies close against the hinge h, or the point where the two valves are firmly joined to each other by a dark-brown, crescent-shaped, elastic body, I, known as the ligament. This ligament, while it serves to attach, also tends, because of its elastic properties, to separate the valves from each other at their broader, free extremities. In life, this separation of the valves at their wider free borders admits of the ready passage of water inwards to the gills hs fairly describe the mechanism of the shell and the manner of its relation to the soft i)arts, and also partially indi- cate the reciprocal i)hysiological relationshij) subsisting between both. The structure of the shell is laminar, or, in other words, it is composed of very numerous and thin parallel layers of calcic carbonate ^chalk), 1 iiruKU.) MKK-lIIiyrOKV 01' THE oySTKR. 8I> .^ (U'posikMl in succession one nixin tiie top of the oilier by tlie niantlo in an orpiuii: liorny niutrix Known as concliiolino. Wiien tiie snrfaee of these layers is < xainined nniler (he niicroscope tlie eaieic carbonate la found to l)earriin;r(Ml in miiinle jiolynonal liloelisor laisnis. The horny matrix of (lie siiell, as well as tlie caleareons matter, is deposited l»y the mantle, and is jjrimarily derived from the food and earthy matters swallowed by the animal. The layers of ealean ons matter, deposited as they are internally, as growth proceeds, project in succession i)ast each other at. the free ed;,'e8 of the valves and i-xtcrnal surfaces of the shell, so that the sncc'cssivo deposits may b(!lace more rapidly at one part of the margin of the valves than at another. Cavities tilled with fluid are frequently found in the ci'lcareous valves of the oyster. They are usually shallow, .aid of no very great extent, and aiise in consetjuence of the numner in wlii(!h the calcareous nuitter is dejiosited by the mantle, the new layers not being laid down in im- mediate contact with the preceding ones, where the cavities are formed. Such cavities are al.so sometimes formed in consequence of the encroach- ment of mud between the valves, as shown at x,x,xm Fig. 1. In such caso-s the animal has sunken too deejily into the ooze, wliicli then found its way into the shell while the aninnd had its valves parted when feed- ing. The nuid wliicli in such instances has insinuated itself between the mantle and shell is immediately covered by thin deposits of calcareous nmtter secreted by the border of the nuintle. Inclosed in this way by calcareous deposits the included mud is rendereil harudess to the soft and delicate structures of the inhabitant. In Fig. 1, the back or dor.sal side of the aninud, it nmy be observed, extends anterioi ly from n to y; the ventral or lower side n'aehea from e to y. The right and left sides of the animal are covered, in life, bv an organ called the mantle, mt. (In the figure the mantle of the right side has been entirely removed, excejjt a small triangular patch vit', which is closely adherent to the front part of the body mass.) This organ is thin; it is in fact a Hat membrane, which is not attached to the shell anywhere excei)t around the jioints where the ends of the adductor muscle M and the pedal muscle p' are allixed to the internal surfaces of the valves of either side. This organ, as may be seen from the figure, incloses, like the covers or lids of a book, the other solt i)arts, viz, thegills, body, and palps, which are in truth susi)ended between the two great right and left leaves of the nnintle. The margins of the nianllelobes of either side are joined together tor only a short distance at the head end of the auimal, or from n to z, forming a sort of hood over the mouth and great 3W I'OSSIL OSTRKIDit OF NOHTH AMKRICA. fleshy lips or palpH p, iiml closed iibove tlie latlcr. roHteriorly, at y, wlit'icthc (,'ills terniinate, tlio tiiaiitlo leaves of opposite mdcH arejoiiied together by a narrow transverse nieinbraiie, wlii(!li extends downwards and lorwards Corniiiij,' the floor of the cloaca cl and the space between the ventral process of the body nniss/ and the gills. This narrow mem- brane IS perlbrafed by t'onr parallel rows of jtores, bp, which lead down into the divided internal cavities ot the gills. I he IVee margins of the mantle are fringed by two rows of short, pur- pli.-li, extensible, and highly seiisiiive tentacles, which are supplied with nerves from the great ner\iiusgaugli(iry(f/,out he lowcriiideoftheadductor M. The tentacles are i)rotrudc(l sli;;|itly beycuid the edges of the valves when the animal is feeding, iuit they are (piickly willidrawu upon any intinialion of danger by ihe contraction of the slender, brandling, mus- cidar buiulles which radiate (Uitward in all directi(Uis through the man- tle leaves of either side from around both of the insertions of the great adductor .lA The radiating muscles of tl antle cross the marginal ninNroccHHes, arraiiKtMl liiui tlie teefli of u comb, Niipiiorted at the outer marfiin of about live bony aniiie.s, with j,'il! elefts or slits between tlio latter, wiii(!li open onhvards Ironi tlie fore part of the sidesof tlie tliroat. In the o.vster tlie f,nlls liave no eorniection witli tlio throat, and Iiavo, moreover, as aheady staled, tlie form of elongated saeks, with porous walls, with a row of large i)ores opening above info the cloaea cI,uh Bhown in Tig. 1. Tlie lateral pores between the ribs on the gills, and oi)ening into the cavity of the latter, and these cavities in turn opening by way of the rows of large ]n>ivs,hp, into the cloaea cl, iiermit tho water necessary for respiration to readily i)ass through the gills, as indi- cated l)y the course of th»! arrows in Fig. 1. The way in which the water is forced through them is, however, quite dilferent from that observed in fishes, in which the water is ])nmi»ed through the gills by tlie action of the mouth and gill covers. In tho oyster, on the other hand, fresh supplies of water are swept through the pores and internal cavities of the gills in an entirely dilfer- ent way, viz, by means of very numerous minute and slender processes with which these organs are covered. These proceiises, or cilia, as they are properly called, vibrato or swing to and fro many times per second, and more forcibly in one direction than in another, so that they set up a current of water in tho direction of their most forcible vibration. This, in brief, is tho means by which tho water ia swept through tho gills of tho oyster in a continuous stream, ministering to respiration or oxygenation of tho blood of tho animal in its passage through tho branchial organs. Tho blood of tho oyster is normally colorless, and much more watery than in higher animals with red blood, in which tho blood-cells or cor- puscles are also discoidal or oval and flattened, while in the oyster they are nearly globular, as usually seen floating in tho serum. They meas- ure about one three-thousandth of an inch in diameter, but vary some- what in size. They are in reality very small lumps of protoplasmic matter, provided with a nucleus embedded in their substance in an eccentric position. They undergo great changes of form when taken from tho animal alive, and may live for four hours under the micro- scope, during which time they may be observed to slowly thrust out; finger like portions of their substance in various directions, and even move about slowly by means of a progre-ssivo flowing motion of their own glairy substance, much like those remarkably simple animals found in i)onds and ditches, and known to naturalists under the name of a»»- ahw. In their movements, as watched under the microscope, two or more blood-cells of the oyster may even actually flow together and be- come conflueiit. Their function is in all probability of very much the same nature as that of the analogous corpuscles found in the vessels of higher animals, viz, to minister to respiration and the processes of 3 INT 21 822 FOSSIL OHTHKin^. 01' NOUTII AMK.nirA. vitiil wiiHfo luid r»i)air. It is likely lliat tln-.v mo lonncd iiidirpctly from tlio imtiitivo inattoiH wliicli liitvclMcn ii1».s<;i1k'(I IVom tlio looil tliroii^'li tli«( walls of tlio iiitostiiio and Mtoniacli ; in fact, tiiin Hcctii)n8 often mIiow an almnilanco of similar corpuscniar bodies in tlio tissues immediately adjoiniii},' the intestinal walls, tiie preseiieiMif wliieli in Kiieli situations would seem to lio most ieadil,\ explained by the view hero su;;;,'ested. Wliatover may bo tlio modo of tlieir ori^'in, tlieir struct mo and ani(eboid climaeteristies would indieato that as they are earned through the body of tlio animal by the blood current they take an allimimrtant jiart in tho processes of prowtli and renewal of struet- uro and tho oximlsiou of woni-ont or elletc materials, both liquid and paseous. The vas(!ular system of tlio oyster Ih not very easy to deseribo briotty in an intelli;;iblo manner; in fact, it is not yet clearly understood in all of its details even by jirofessed anatomists. The writer has, however, traced tho princijial vessels and their connections with tho heart, body, and Kills by a variety of methods, tho results of which will bo given h'ro in outline. The heart of tlio oyster ia a much simpler organ than that found in man or the hifjher animals. It consists of three principal divisi(ms or chambers, viz, a ventricle, partially divided in the middle line of tho body by a i)artition or septum, and two smaller inferior chambers, ono on either side, with darker walls than the ventricle. The - 'alions of these iiarts to each other are shown in Fiji's. 1 and 2, at re ■ u. The three chambers of the heart are lodjfed in a cresceiitshap* 'y juMt in front of the adductor M and between the latter and llie oody-inass in front, as may be seen in Ki^'s. I and 2. This cavity isclosed on either siile by a thin membrane, which is rei)resented at c, in Fig. 1, detached at its anterior border from tho body-mass and thrown imck over the ad- ductor muscle. It contracts much more slowly than the heart of higher animals, and even much more slowly than that of snails or gas- trojiod mollusks. The normal number of beats of the heart of the oys- ter in life i)robably does not much exceed twenty per minute, if its pulsations are even so rapid as this. When fully distended the ven- trido nearly tills the crescent-shaped s])ace in which it lies, but falls far short of filling it when contracted. These two ojiposite conditions of dilitatiou and contraction of the heart are rejiresented in Figs. 1 and 2. The walls of the ventricle are very much thicker than those of the auricles, and aro mainly comjiosed of muscular fibers, which interlace with each other in various directions, and wliicih contract and elongate simultaneously, so as to increase and diminish the capacity of the cav- ity of the heart alternately, thus constituting a veritable living pump- ing ai)paratus. This apparatus is rendered still more effective by rea- son of the two valves which are interposed between the ventricle ve and auricles au, the presence of which prevents the blood from flow- ing back into the auricles from the ventricle when the latter contracts. T ■rKKii 1 LIFK-lirHTOUY OF THE OVHTKR, 32 :i TliOHO valvoH ivf tlii> lower cud of tlio vt-ntrido o|mmi upwiinlH, ho tliut wo may roiilldciilly inC-r that llio lilnoil of tlio oyster tlowM eoiiHtaiitly ill oii.'.linMlioii, or from tli<^ auricles tlir.Mi«li liie veiitrielo and from ♦'; ' tliroiiKh (ho Kreat posferior and anterior arteries a and «', to ho dislriliuted to the o|t|io,site ends of IIk* Imdy. Tlie liind.'rmost arl.'ry a carries frcsii l.lood mainly t(. tiic -reat miis- cle ,1/, while the anterior one «' carries hloiKl to tliu hody mass anto- Horly. After entering' the hodyniass at a' lllie anterior artery imme- diately diviilcs and mci-N i. (h.rsal branch n' forward, ami a' ventral brancii a" downward and forward; lliese two vessels are shown cut iicros.M in the Ncelion represenled in Fi;,'.,). The tw«, main anterior ar- terial iwiKs j,'ive otr many small hraiiclies at intenals which fravcrso the soft Niilistance of tho body, but in some portions there seem to ]w iio true vessels, but rather irie-fiilar vascular spaces whicdi in all proba- bility communicate with the vessels Just described. The tissue in which wo liiid more or less evidenco of tho existeiHH! of irregular blood- Hpaces, is that indicated by tlio letter e in Fi- 3, and is tho lissuo which envelopes all of tho internal oifjans, extending; even into tho mail- tlo and gills. This common sni>portiiig or (ionneotivo tissue forms tho walls of all tho great arteries and veins throughout most of their c-xtent, especially when^ these traverse the soft body. mass, |.alps, and gilK, A few of the vessels Iiavo proper membranous walls, such a. I ho branchio-cardiac vessels br, Fig. I, which bring the blood back to the heart from the gills, mantle, and roniil organs. At the lower side of the body a larg(( vein, tho voim cava, vc, Fig. ;t, receives tho blood from tho u|»per and anterior part of tho body to eon. • vey it to thegills l(» bo oxygenated before it is returned to tiio heart again. How tho blood sent from the heart to tho hinder part of tho body is carried to tho gills and back to tho heart, tho writer has not been able to mako out clearly. Tlioro is also a system of vascular channels which traverse the adductor. Tho arteries of tho palps are snpcrlicial, and arc shown in Fig. 1, but in the dcci)cr, fleshy portions of tho palps, deflnito vascular channcLs arc replaced by irregular vascular spaces. Injections and sections also show that there are dcllnito vascular channels in tho maiitio and gills, and in the former, cspe(;ially when tho oyster is very emaciated, thesd KOiiK^times have very thick walls. To sum up what wo have stated regarding tho courso of tho blood, wo find that it passes from tho gills to the heart, thcnco to the various parts of the bo.ly, and then .lircctly to the gillsagain. Itwill bo noticed that this is an arrangement very different from that found to obtain in fishes, where tho heart receives the blood from all parts of tho body, sonds it through tho gill.s, and then on directly to tho various parts of tho body. Tho difference between tho circulation of the oyster and that of a warmblooded, air-breathing animal with a four-chambered heart is still greater, from the fact that in such forms tho lieart receives the I " 324 FOSSIL OSTREIDjE OF NORTH AMF.niCA. blood from all parts of the body, sends it to tbe lungs, receives it again from tbe latter, to finj.lly again send it off to tbe different parts of tbe body. The food of tbe oyster is very various in cbanictor, as we find tbe remains of small crustaceans, molliisks, larval worms, crustacean larvte, rbizopods, diatoms, &c., besides inorganic eartby and siliceous mate- rials, in tbe stomach. It is i)rol)abIy omnivorous, as U. Certes has hap- pily expressed it ; the only condition which seems to he requisite In any or^Miiic body to fit it for I'ood for this animal is that it shall be small enou-j;li to bo passed tbrou^'b tin wide but vertically nincli constricted montii and throat. The great bulk of the food of tbe oyster, however, probably consists of minute marine larvic, infiisorians, and ji-iiASsie I aae FOSSIL OSTREID^ OF NORTH AMERICA. V / Fig. 1 9, 10, 11. PLATIO XXXV. GuYPii^A CAI.CEOLA v;u. NF.i.iuscKxs/s Mcck & Ilajdeu. (Pago 290.) .— r,.\tciior view of a loucr valvo ; naliiial size. '■—I ateriil viow of anotlior lower valve. I.— Iiitorior view of tlie same exaniiile. .—Upper vi.'W of a small example. '.—Interior view of an npper valve. Aftei »,reek. OsTHEA (Alkcthyonia) ntccu.MiiKNs White. (Pi,goS90.) .—Interior view of a lower valve ; natnral size. .—Lateral view of tlio saiiio »peeimeii. .—Interior view of an ni)per valvo. OSTKEA .STKIGILECULA Wllito. (Pagc989.> —Exterior view of a lower valve ; natural size. —Lateral view of the same specimen. —Interior view of an upper valve. V i I. «. ^'illl.O(,ICAL eiilVICV '^rr%?^. '^■VM-AL KProui 1SS3 1... xi;,,. iUJ JL'RasSIC. 3 INT 22 888 FOSSIL OSTREID^ OF NORTH AMERICA. W ' Fig. PLATE XXXVI. OSTHEA COALVILLKNSIS Mcek. (PllgO 293.) —Exterior view of an upper viilve ; natural size. — Interior view of tbo eanie example. —Exterior view of a lower valve. —Interior view of the same example. After Jleek. Osti{|;a ELt;oAN'TULA Newherry. (Pago 295.) -Exterior view of an npper valve; natural size. —Interior view of (he same si)ecimen. —Exterior view of a lower valve. 'i»iK.\ IM. XWMl 1 t liiriAcKor -^m ! ^ ■I // '^ J 342 vomL (mnv.wjE oi- noimh amkkica. I'I'ATi; .\.\X\III. OsTiiKA Ml i.TiMitAT.A Conrad. (I'.itii'y'JH.) *'lae.l,'.'.-Exfcrior views n,-,w, lor-nr, ox,u, ; natural Mzo. > 4. I I • iiKOI.riiili Al. kl'KVUV ANNi II. nFi'i'iir IKHM 11 xxxvill I i!i;i.\(i;age;!00.) -Uiiper view ; natural siz.>. After Meek. O.STliiCA co.VGKSTA Coiira.l. (I'age2!>4.) After Owen. "■'■'''irllr'-^-^'"-'^^ "•''^•"■•' '"'' '-^" -^"'« «'■•■>• or a large 13. -Interior views of upper valves. After Meek. ''' ''■i^''ljgafcL„jtMMii>ij!^j^ U. X. liEW.OCilLAI, KCIIV VNM'Ar. IlKmiM lt.K3 I'f,. NXXIX I I 1' •■H'':iA(i:iiis '/ '/ 1 I 34G FOSSIL OSTREID^ OP NOB' AMERICA. f PI.ATK XL. OsTliHA DII.UVIAXA LimiiUMS. (PHgo29,->.) 1-iO. l.-Lateral vi..„- ; „,.t„r,al Hi.o. V„r „H,r,. vi.ws sec no..t ,.l,.t„. OSTIIKA C1:HXUMMAI!GIXATA Gabb. (Paso204.) a.-lMtcrior vi.Mv „r „,„ ,„„.cr valv,. ; n,.,v„al size. Aft,.,- Gal.b. OsTiiiCA KonusTA Conrad. (Pago ;!00.) ;!, l.-OppoHite vicwH of Conrad's typo speci.nen. After Conrad. OSTRKA IMtUDlSXTIA White. (Pagi, 099.) 5, C-Opposito views of one of (ho type specimens; „..l„r,a sizr. 1 ■ ti» WBO ■ vb CKl'.lAl l:(H,B, h f — ^^^^ '7 a48 Fossii, osri;i;ii).r. oi' \ iimii amtkica. I'l-ATK Xl.I. OSTREA DII.rVlANA LilimcilS. (Vixirv U'Xi.) Fios. 1,2.- -Kxterinr mid intfiior vicwaof tliiMipper viilvc; iiiitiiralHizc. Foralatoral view (if tlio same pxamplo sec Plate Xly. OsTEKA i.uouiims Cdiirail. (I'ago2t)7.) 3.— Exterior view of an under valve ; natural size. 'f i .1 » , r. «. >il{lll,(ii.lr.\l, hTH^H AVM Al. I!l Tdlir !«►:! I'l.. M 1 ( iiK! A( iXirs. L IMAGE EVALUATION TEST TARGET (MT-S) /. 1.0 1.1 11.25 US 1^12^8 |2.5 u, lis "^ £ in i2.0 1.8 U. 1 1.6 1^ m >> 7] ^^ A Photographic Sciences Lurporation 23 WfS? MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 ^^ iV iV \\ lV >.. O^ ^ ■^ '^fc i o^ i ■I '■ .1. • ?i! r I mmss. 1 iUO FOSSIL OSTKEID* OP KOBTB AMERICA. H / i PLATE XLII. OsTnEA flOLENiscus Mook. (Pago 300 ) OSTIIEA (AI.ECTUVONIA) LAIIVA LaM.arck. (Pago 296 ) r t i V. S. ' EOl.OUlCAI. HI'IIVRY CliKIACKol's. >. !l n' ' ■;t I' 4 352 FOSSIL OSTUEIUiE OF NOUTII AMEKICA. / u PLATE XLIIL OsTRKA CAHINATA Lamnrck. (PageaOS.) PlO. L— A largo example; natural size. After Rmmer a. 3, 4.-Throo different view, of a smaller example ; aUo from TexM. OsTREA guABRiPLiCATA Sliumard. (Page 299.) 5.-Exterior view of a lower valve having „„„H„„„y p„„.i„,„t ,„^^, „„j„^^, 6,7.— Copies of Slnimar'J.) Klo 1.— Kxtciuii vii'W 1)1' ihu liiwi r Milvi.'i |]iiiiii:il ni/.i'. M.VI. It .1# I'. ». (,K.iiMi.'! IM.. XI.V CKiriAlKOl'S. u i I ' 858 P0S8IL OSTRKID* OK NORTH AMERICA. ^ PLATE XLVI. 08TBKA BARHANDEI C'oqUJind. (Pll|Te s!92.) FlO. I —Exterior viow of the iipiicr valve. I'l.r dIIut vicwh mo I'hih-.i XLIV anil XLV. OSTREA IILACIUI WllitO. (Pllgoa'J-J.) a.— Exterior viow of the under viilve. Tor Iho opposite viow »e« I'lutn XLV. .* V, B. USOLUUIIAI. itLKVKr ANXLAI. IIEI'OIIT 1883 I'L. XlVl % ^ I i CUIiTACEOL'S. \ I 1 aeo roHHii. osimwM of noutu amkuica. i 1 PLATE XI.VII. OsTiir.A riri.i.iPi.u'ATA Slniinnnl. (PiiRoaQB.) Fin. 1.— Kxfrridi view of tliu nndnr side ; imdiriil hIzp. a.— Lateral view of the snnio examplo. 3. — Extorinr view i)f tlio upper valve, OsTliKA I'ATINA Meek & Haydnn. (Pngo 298.) '(.--I'xtorior view of an upper valve; natural HJze. •1. — Similar vii'w of a lower valve. t).— Interior view of the Niinic exami/lc After Meok. U. H. i.F.'il.iii'K tl. Kl ll\ KV 1-5' . * AVM-.vr. iiri'niiT ifH:i ii yi \ u Clii:TACi:i)rs. K^ijs^tesiiJKsweii^ttiw*^**** wmm 3(;-_> I'OSMI. OSIKIMIM, or NOIMII AMl.KlrA l'iii>. 1-,".. -Dill, I'l.Aii; xi.viii (.ItVI'll 1 A V1,.M> I I.Al;,^ I ,,,|.,,|^ ,l\.-,.;ii:!.i II"' virus. ,|-„.|,,„:,lr v:,Urs: „mI „,„ ; .si /,■. Osini'A 1 MI.HIMIS .M..,.U. J I', li.T, -r «c. \ i,\Vs , if 111,. 1,1 I'l- i.llVf 111' M cl^'s t Vji,' S|M',iiii,.ii : li:lIiM:il OsTur.A Vi>\ii:i! .M,.ri.,ii. ,1 i.l':\;,',' :ilH. •*-10.--nillrivnt vi,'\\>.; naliiriil si/t" mwsSimiismsm ifg^m'-y Ti'u^'isiii '■I I'l o..lt \1 ^1 |;\ I \ VNM \1 IMIVilil ISS:! IM . \1,\ Ml cKKTAriiiirs. T-jg-i'i;,! "'■» iiiailiutiiiilinil ^tiT^rrr Tiiiggl I If I , ^^ 864 FOSSIL OSTKKID^ OF NORTU A^rKRICA. I'l.ATK XLIX. tiiivrii,i;A iTiciiKHi Jforton. (Pnge30!>.) F,G8. 1, 2.-TW.. vK.ws ..f au oxa,u,,le ......vpi,.,,, t„nn, natural size. 3.-I,,tenor v.e«- of ,l,c Unu-r valve ola y.r- largo exa.nple « J 4 'f I ) V ^ ' •r^ .1, 866 r<>.SS||. (ISTKKUMC Of NOKTH AMKK.fA. (. ri.AiK 1.. I'.XiMiMiA IMNDI-.IIOSA l;,.clll.-|-. (l':lg.' ;iOl).) Kios. 1. 'J. -r|,,„.,inul iii:ar,\i,.«.„|;,.M.SMUi|.l.M.|;,lH,ut lialf (nil iiA Mecli A llayd,'!!. , I'aj;,. v'!'il. ) .■>.— Kxtciidr viiw Dt'a low.-i- valvr ; natural fi/.r. ti.— Oppositf vii'w of ih,. f^anic ixaiii|ilc. OSTiu'A MAii.i:iK()H.Mls (ialil). d'ayi' 'J'JT. ) 7.-Kxt<.riiir view of an iippiT valve; natural size. After Gabb. . t 'ti' tl!I'.TAli:i)ls. v 1 ' ! t {. ■I « 3(iH I'OSHII, OSTIIlulD.V. nr NOIJTII AMI.I.'ICA. I'l.ATi: M. K.VnOVIlA TKXANA li'llilllcr. (I'llH" liOti. ) Fias. 1,'J,:!.— rp|M r, undi r, and liiliial vicwHdfa iiriuiy iidiill cxaniiilc ; iialiual m/.v. ■liTi. — Interior vinWH (pf Ihc niidi i and iipprr valvi'S id' tin' ■■aiiH' i\aiiii)li>. AI'liT Ka'inor. i I |l. ». llHi|lli,|l\I M IIVf> ^^M \i iri'niM \"-\ n 1 1 rlii:iAc Kui-s. •?r— r I V ■ ,j..iK.i:,im.r;c^ ■ ■■:■ :.y .n-nr: ,T INT I't ! 370 FOSSIL OSTREIDiE OF NORTH AMEniCA. PLATE LII. E-XOOVHA I-Oa.V.CULATA Wl.ito. (P,... ;,„5 ) HOS. 1. ..-Exterior a„.n„..H,,r View, of , U„ ..,,,. r valve , natwra, «i.e. K-xor.v,u r.^,v,u.scuLA R,.,„e,.. (Pa^o m ) KxoovKA w..vcnK,.,.Mvi,it... (Page :!07.) '^' — J^xterior and intirinr x-;,.... .■ >.. ^ f. s. f:pnr.4»;IrAt. SIMt\'l,V AV^ lAT. lin'dllT 1HX:| IT., 1,11 I .«<; «'Ui:iA(.i;i»us. I i >l 1 i I \i 372 FOSSIL OSTREID^ OP XORTII AMERIC/ % PI-ATK Llii. EXOGYIU AQflLA Gol.llllsR. (Pa?o304.) Figs. 1.2.-npj.er and under viewH; natnral size. 1^ 111 M j. L'. K. UEOLUdllAL BLHVKV ANSI'AI, IIEIOIIT 1883 n,. I.III I ,,. *M CUKTAOKOUS. '_' ^i^S^i-VlM'-tii* * / rt I Hi , I I 374 Ko-ssu, osTH.:,..^.; ,„.• sonru amkrfca. |;^/ « i i. n i' ; « r. H, (.Klil.iK.li Al. M IIM V .\.>M tl llHI'lll |l■^l I'l.. I.IV ■-,* CUETACKOLS. .v I ; ■1 i Wi r\ 580 FOSSIL OSTRKIU^ OF NORTH AMKRICA. i PLATE LVII. KxoGViiA cosTAiA Suy. (Page ;i04.) rio. 1.— Exterior virw of a lower viilve; iialural size. •-'.—Lateral view oC llie same exaniiile. ,J I. ». OKOUK.ICAI, K UVEV ANNIAI. llEroUr 1HH3 CI.. I.VII 1 i!i;iAi 1:111 .-i. n kM 382 FOSSIL ostukida: ok noutii amkuica. PI.ATIC LViri. OsTltEA OLAliiiA Jlcek it H.iydcti. (Piig>' :!07.) Viaa. I,'J— ExtorioraiM ii.t..ri..r vimv. of tho typo specimon ; imturul si.e Af Meek. 3.4.-Siiiiilar vitnvH of a lower vulvc, fioni Colorado. fur I, • c.rAi.iiriii \t. Biiivrv ANN! Al. llfllMll l""! II I * Ml ( f r if. \i ii 384 FOSSIL OSTKEID^ OF NOUTll AMERICA. I'LATK LIX. OsTni:A GLABitA Mook & llaydeii. (I'.ifro :ii)7.) FlC.s. 1,L>.— ICxtcrior and intcrioi- vuiws of an upper valve. :!,I.-Si„ular virus of tlic lower valvo of tlio type specimen of 0. Wliile. r..— Upper view of tlie type specimen of O. amialilis Meek. ■. S. (iROI.OCIlAI, SIHVKV AXNTAI. I.'l.l'oiil IrtB,'! .■!,. I.IX LAKAMIi;. 4 I: i 4 3 I]N1- 386 KO.SSII. nSTHKlDiT: or NOKTII A.MEKICA. I' *" I. I t i ri.AlE i,x. Omrea Gi.AiiHA Miili A Iluydiii. i^PiigeiiOT). Kios. 1,~'.— Extfiior anil inteiiDi- virws ot'ii Colorado i-xiimple. ^,4.— Similar views of a WyoiiiinjT i.xaiiiplfi. i\ / L'. s. (iF.oi.onicAr. una 'n ANXI'AI. IirrOIlT lOHa I'l.. i.x . .i - ^ *1 r.AllAMIK. ! I ■i V 1 I I i < \ ^' n^MjimmiBmkm^ I k 1 J88 I'OSSIL ()STI.'l;ll.,r. or NulMii AMKUIfA. 1 ri.A] I. i,\i. Ush:|.:a i,i..M>ii.> .M,,k A \\.>y\,-u. . I'a;;,. :!07. ) I'll-J. 1.- Inll'l-i,,! vi,MV „r,M lower wlUr IVUIU \\'.„Mhv' ii.:!.-U|.l..Ta„.ll.„.,„lvi,.v,„r,.|,e,,i,„..,.,- th,. ,,«!.■ .,f Nuev., Le.,,, M-ii, OSIKIIA Mllll;l(i,,.SAi,T< Kv.'lll.- A M, :,|. fp.,^,,. mw ) ■l.-K.\lcii„i- ^i,.^v.,l^nl ii|.|i.r v.ihv: ,.,Uiii;,l ni/..-. • I. — Interior view (ifllii. «^,iiie ex:iMi|>le, I.AltAMIK. I ^ u 1 ir wir^fwr^'' (: •i' ^,. ..IJ.I1II ^Plilll! 1 I 390 FOSSIL OSTlfEIDj: OF NOKTH AMKRICA. PLATK I,XH. OsriiKA SKLi„KKOi(Mis Conrad. (PHye 311.1 FlO. 1.— Upper vitfw; imtmalsize. 2.— Lateral view (iftlio.s:iim« exaiiipl.'. For miolher viow si« I'hito XXX. fk i ' I . ^. i.lnlAHiliAI. Sl'UVl.V anntai. itKronT l«sj n.. i.mi ld i ! 1 I timirlllii 'is^swmmm I I. IM 392 FOSSIL OSTKKIO^ OK NOKTH AMKIilCA. f ( i'l.ATK i.XIII. OsTUKA sKi.r,.f.Koi,','is, Conrail. (Vh'^. A]).) Km. 1.— IJiidnr view of tlii> c.x.iriii.lc iliai isli^nrcd ,,ri I'liit,' XXIX. (.)sTi!t:.\ vicK.sBi-i:fi|-..v.sis, Counnl. < Piijjr- :;i-,', ) •■i, :!.— Kxtcrior nml iiitcn.ir views ot'.-i IniviT viilvp; n,itiii;il si/,i-, OSTUKA Tiiiim,*; Galili. (Puirpilll.) 4, .'), t).— Kxtenoi, lateral, and interior views of a luwor valvi ; naliiial size. i;. s. (iKcii.nnicAi. .-ruvrv VSMAI. lirroiri IKK) [■[.. \.\u\ £ l\ f '■ ' !l » ,4! IStC»::w^^sr'^^ai!«. — -ia:aK'J"-a^' zsasvuui h .-...JllJ.. JUP. mmmmmmfi 394 mmmm FOSSII, c»srKK,Il>,4: OV NfUMII A>[n!I(A I I i I I'l.Aii; I, XIV. OsrilKA lir\ AMICA I A I,1M. ( l':iLre lUD.'l l''l(l. 1.— C(ili,\ c>fI.r;l'Mirij;iM.i| |i;;iii,., l'Sllli:.\ AI.AHAMKN.-IS l,,;|, ( l'ili;|. Illl'.l. ) Ku). •,',— t'()|i.\ 111' I.cir.s 1.1 iMiiiiil li;4iiii', ;i.— Coii.v ofl.i'ii'M li«iiir (if iIk' I'onii lie ciillrd O. U„ij„u-canil. 4.— (.'Kpy (.n,.M\ liijinv c.f 111.' I'l.nii lir I'.illr.l (I. s,n,i-h(,iata. (1.SIHIA i:vi:i. (1.— KxliTiiii- 1111(1 iiifcridi- views of a lower valve. 7, 8.— Siiiiiliir vii^ws (if an upper valve. Alter DMliaveH. i. I < > ^ !■. H. i.ii.icii.ri \i, Mi.'iivi:v i ^( : IMAGE EVALUATION TEST TARGET (MT-3) to I/.. ^ 1.0 I.I 11.25 lilllSi IM nH 2.2 a Hi ■ U 11 1.6 — 6" Photographic Scimces Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 873-4503 '^ \ iV A \ '^ •^ ^^^- -<*. <«^>^ <<^.*' 0^ 1^ t o^ Wi ff w 396 KOS.StL OSrUElD.f: OF UOHIIl AMIiHICA. I, ^•) 1'I.ATi: l.v.V. OSiBKA LO.Mri!KSSlI!llSTl!A Say. (TatiM ;;00.) Kir.H. 1. -i " r|i|,pr jiiul iiMil.T vip«K ,,|- ;, lnn;o oxamplo; iialural size. 11 t 1 ^ L M ,1 11 I i ( i ■iBiWruy... 'I HU.Jl'MlUUl.jm li a;.'S KMasii, ()sll{Klli-t: OK NOKIll AMi:UlCA. I dh 1 I'l \ 1 1; I. XVI. '>-iKr,\ lu-rMiii IS ('(.iHiiil. ,1'npe ;)12.) FlQ. 1.— Uci'tr vie" ; naluiiil (*i/.c. 2.— I'ndiT view- of atiotlKT i^xiiinplf Al'i'-r Conrad. m 'T '^•ii¥'~' 'mm ".T 1 «. iiKDI.cillil Al. «rilVKV A.NM Al. i:l I'nlll Imi:; I'l. l.X\ I « 1 Aii(Pli;XK i ( • "'««|!( '-1 Vf w 400 ros.sii, u.srin:ii»jo (»!• nouth amkhka, , I ll I'l.Air. I,X\ M. O.sruKA iAV|iii;iA\.\ (ImIiI,. (I'ii;;!. :;i;t. ) l-'liis I, •.'. -Upiicr iiii'l laiciial \ ii-w.s; imliiriil sizo. AI'IctOuMi. OsTiiKA I'i:k( i;a.ssa CihujiI. O'iij,''" ^ilH.) H— Infrrior vimv of a l,.uii' \,'ilvi>. At'lcr Ci.iir.nl. I. K. Iimni'i.ll A\ »l IIV>\ ASM *l imi'""! I«»' I'l IN* II ; r* fi t •f. • y» ^ 3 INT 26 ri ir i i« i 402 FOSSIL USTKKID* OK NORTH AMERICA. ri.ATE I.XVIII. i>mhi:a >l itiAicAiA ('i>iira(l. (Paf;o :U\\ ) Fig. 1. — I'ppci- viiw ; natiiial k\/.i\ ','. :V— Kxli'iior :mil inlriidi- vic\v> ol' an iiiiiU'i valvo. (>stki:a Airwdoui GaMi. (ra);i's 111,' ami ;tl4.) 4. — Kxtciior view ot' an under valvi-. 5. — Interior view of another nniler valve. Alter Gnbb. t HMMit»«iaiMiM«MtfM«ai«iiMri L'. fi. Ct^oUKilCAI. MI ;tVFV ANNfAI. ItKI'OIlT lH8:i IM,. I.WIM •^ ■f^ MKPlKXK. t ( I I 404 KOaSII, OSTRKIDiE OF NORTH AMERICA. PLATP LXIX. OsTHBA coNTRACTA Conrwl. (Page 312.) I'iGS. 1 . y.~Ext.rior mul inferior vicnvs of a large example ; one-third actual diameter. After Courad. -4» 4. f. M. ilKol.ocili .11. KlllVKV ANMAI. hKl'Oin IWKI I'l.. I.XIX ■ff Mi r \i i I I' 1 i '?EK»-5li;--^5*S?T»^£V:^4J>^!«j3^!*S imr::!".-*^'^:^!^ ■ I 406 FOSSIL 08TBEID.E OP NOHTH AMKKICA. PLATK LXX. Omtiika vklkiiiana Ciiiirnd. (Page UM.) I'lO. 1.— Kxterlor view of a lower viilvi'. Al'liT Courud. OSTKKA 8CULPTUHATA Coiirnd. (Page 313.) a.— Upper view. After Conrad. C» 5 I'. • lIKiiUlillrAI. KlIlVKV ANM'AL lltl'lilir 18X3 I'l.. I. .XX <» -• MIOCEN'U. I f 7 'I i, 1 408 FOSSIL OSTKEID^i OF NOKTll AMKKICA. i I ri-ATE I.XXI. 0.iTI!\-A liiiri!nKOi-.ii ; Rem. Mill Wi;ilili. il'.inf ;il4.) 1-"IG. 1. — Kxti'imr vii'W ci' n lower v;ilvr. Al'trr (ialili. ItsTKIA VK81'|;KTINA ColllMil. vl'.li:'' iil.'i.) Flu*. •-', ;!. — I'.xtciinr mill iiitorior virws i\t' m Iowit vnlve. 4. — FsltM'iiii view ot' iin ii|i)iiT v.ilvi'. At'ter Cimiiicl. <^ >% «^. iJll^ I-. s 111:111.111 ir.n. SI iivi:v AWTM. Ki'i'din l.-.":i n 1 \\i «i <=> I'l.KH KNK. V i ^> •^^ II i I\ 410 FOSSIL OSTKKIDii: OF NORTH AJiEKIOA. PLATE LXXU. OsrrtKA VKATCiiii (Jiibli. (PukcwIG.) Flo. 1.— Exterior view of ii lower valve. After fJabh. OsTliEA CEUKOSKXSIS (KaiiiioiKli) Galili. (Pago :!15.) 2.— Exterior view of an upper valve. After liabb. OsntKA I.UHIOA Car[ieiiter. (Page31G.) Figs. ;!, 4. —Exterior and interior views of a lower valvo; natural .size. '? ! ■ tSR"i 1 i r. R. r.Eor.nr.ic.vi. sritvKV ANNl-AL ItFVOUr 18H;I I'l . I.X.MI 't- -^- «K1 J I'OST-IM.IOCKNK. fi I I I 412 FOSSIL OSTRKIU^ OK NORTH AMERICA. ^v^ PLATK LXXIII. Fia. 1 represents »» Anu'ricaii oyntci in a moderntely "fat" cu.litioii. The heart ot th,8 spee.men, afCr l,ei„g opene,! for ..v.t t,ve„ty.four hours and exposed to .),. "ir, would still 1>oal leebly if irritated. ' «and «' f;i,.ataorl:e or arteries s-vou oil a. ll.eso poiu.s from the vent, i.ks „u . Rht nnnele ; hr, braneluo-.-anliao vessels ; l,j, or^^an of liojanus i„ outline ; /,,,, bran- elnal pores; e, pencardiae nu-nUrane of riKlit sid. thrown baek ; d, eloaea or eloaeal spare ; rf, „ervons.,.M,n.l.Knreof the right Hide eo,,ne.linK the parl,-to.sp1anchnie ran- .on ;,j and the snpra«>sopl,a,..aI ganglion ,g ; f, veufal proeess of the bodvmas:: ., g,l s; ,e. o„l eavuy he,we,.n the n.antle l.aves; /,, grooved hinge-end of L IWt u.he, /, l,gau,ent ; .V, adduetor n.nsele; ,„/, n,antle; ,«/', portion of n.antb, adhe- rent to body-uia,s«; „ (o ,- n.arks ,„e ext,.,! to nlnd, the riuht and left lea,.., of the mantle are conllueul ; ;,, pall>s ..rlips ;/, outer end of p.dal nu.sole of ri.^ld side • *' external opennigof the generative and renal organs of the right side ; r, vn.t or an,,. '■ re, ventnclo, .r,a-,.r, cavities iu the edge of the shell llll,.,l wi,l, n„,d ; „. posterior ex^ tromity ol Ihe gills and. jtmetion of Ma. leaves ..r I lie mantle. » » i 4' %4* I.. ». l.KUI.()llll Al. Ml IIVKV A.V.NLAi. HKriPlir IHSI |.|,, I.XXIM ♦ » ^3 ^H I.lviNii osii;i:iii.i:. K J 414 KOH.SIL OSTBKMiiE OK NoKTII AMKIIKA. r \^ V I'l.Aii: i.xxiv, rid. •.'(I""-,.,). .IH. aMricl..;/,,,,, ImmIv ,„„s,. ; , /, ,1,„„ a; '/, KiH- i i nmU', ii.lrstlne; Mivrr, will. i(«,lMriH,)i...iiini; into tlir st,, 1, ; .1/, „,|,l,iet,.i-; m.nmnth; ml, mnn- rloj », plan., ihton^'h whirl, the w.ti,.,, i..|,r,.„.,„..,l i„ V\g. ;; „aH .■,.(,; ;,, oiitrr .•...•- rii){.ilc(l Niirt'ai'o of iniii'i- w lnwcr palp ; r, vcmiI ; re, vnitrii;!... Via. M(iipp,.i). S.tiioii llimuKl. th,. plan..»„r li«mo •,>, Ni.s,,,! |Vo„, ,i,r animor sMl... and .nlai-...! al.oi.t two ,liani,t.rH ; ,.' ami n", .lorsal and ventral Inan.hcs of fhoanlcnor a..rt.. In Hr.tion ; hr. hianrliial vwl ; ,•, mn tivo tl.sn..; ,/, kIIIs i„ •.•ctM.n; ,/, uifnuil ravili™ of tl„. Kill.; „., la.vn-of K-nriativ.. tisHnror r..p',„,lnclivo nrdan; ',<, '■■■•ss-M.-llonH of the inf.sllMal tiilir, .showing lh« p..onliar form of tho in- tmiial cavity; /, livrr or l„|.ali,; ti-..n.,; ml, niantlo; »*, Bnprnbnuichiul or water iipacos al.ovu tlio kiH"; »I, oiivily of dtoiniich ; it, vtim cava. - -^. ' •w t T i I. ». iiLiiUiiili .\i. ULUVKV ILA- Axsi*!. iiiti'oHr law II c.xxi> -4 Vtb' jij(!J5'iAi»4''*«Sy_ij , l,l\l\li oM'liKIU.K. 711^^ hi i 416 FOSSIL OSTREIDiE OF NORTH AMERICA. PLATE LXXV. Fio. 1.— Young American o^-ster, viowid from tUo side immodiatoly after fixation by tlio mantle border m ; enlarged 183 times. 2.— Four young European oysters taken from the beard of the parent; enlarged 9() times. 3.— Young American oyster, with the lioaks or umbos of the larval shell dovel- ojicd, and firmly attcched to an old oyster-shell | enlarged IHJ times. ■4.— Young American oyster, attached and beginning to form the spat shell. (The valves are slightly displaced.) Enlarged OG.tlmes. 5,6.— Very young spat of tlio American oyster, showing the peculiar form of the true larval shell and that of the spat, and the upwardly directed hinge border; enlarged X) times. T.— Lower valve of very young oyster, showirg the great concavity of the larval valve and the abrupt transition into that of the spat stage; enlarged X> times. 8.— Older spat viewed from the lower surface after being detached ; enlarged 35 times. 9.— The samespecimeu viewed edgewise, to show the flat lower valveof the spat and the convex upper one, and the upturned hinge with the larval valves in place ; enlarged 3o times. ^'- U.— Figures 3, 4, 5, C, 7 and 8 are unfortunately reversed, owing to an oversight in transferring the original camera Uicida sketches. The peaks of the umbos should look to the loft instead of to the right in order to bring them into a natural position. Otherwise these figures are accurate. L'. S, (iFur., palp.s; g, gills, 0.— Twenty days' old spat of the American oyster viewed from above, natural size. C— Forty-four days' old spat, natural size. 7.— Forty-eight days' old spat, natural size. 8.— Young spat oyster, seventy-nine d.iys old. 9.— Young spat oyster, eighty-two days old. 10.— Young oyster, 2i to 3 months old, from inside of a wreck at Capo May, New Jersey. ( 1; L". s. i.lXM.iK.K \i >i (:\ i;v ^■ livim: osTKKin.f. I '• 420 F088IL 08TKK-II)A: OK NORTH AMKBIUA. s^« PLATK LXXVII. Fio. 1.— View of tho iuuer face of tlio right valvo of a typical Aiuuricaii oyster, Kio. y.— View i)f tlio external siirfaco of tho preceding. vuijr i I •. ul.liLOijU.vL >lltvt\ A.VMAJ. lltlOltl IPKII I'l. l.X\\ll I'iv* LIVIXU () i' Mirarrari 4-22 rossiL osTHKiDit; or noutu amkrica lM,ATi: Lxxvm. Vm. 1. \'ic\v cil' ilu' imiir muI'ii'.' oni'c li'l'l or drcpivt valvo lioldiijjiii!; to tlio Kpcci- iiu'i. ii'iutsiiHimI on I'lalc Ixxvii. Kio. -J.- \ it'w .il'llii' cNtiTiiiil sml'.icc ofllu' iiit'iTdin^. i/fM I .K. Ij 1 i 424 FOSSIL OSTRUIDiE OP NORTH AMEUICA. FIGURE LXXIX. Figs. 1, 2. — Views of tlio iiisidoand siiloof tlio very ventricose orcuii-like lower valve ol a short and thick speciiiicu of Ostrra virginica. Figs. 3, 4. — ViewH of the internal and external surfaces of the flat upper or right valve of the same specimen. f t ; t r. B. (ii;(ii.oiiH Ai. SI iivi'v ASKiAi. i;i:riii;i l^«:l n . i.wix l.ivi.Nii <>si im:ii).i.;. c I 426 FOSSIL OSTUKIDiE 01" NOUTII AMKUICA. «*^ PLATK I. XXX. ViiMvH of tlio imu-r anil outer miifiiccs of tlio rit'ht aud left viilv. h of tlio northern form of tlio Auuriciin ojNlcr, (Mrea horealia, sliowiiig tUo lower valvo Htrougly llnteil. «i. t 1'. H. IIKIIMK.K Al, HI IIVHV ANM'.M, IIKI'HIir 1KH;| |i|, I.WX ^ i :^^- -%/%^'^^ l.l\lNii (>sii!i:iii i; '. } If/, I «■' , 428 FOSSIL OSTRKID/K OK NOUTII AMTRirA. ^V I'LATE LXXXI. Via. I.— View of inner smt'iui' of Hii> iij;lit valvo of an eloiijjati'd spcciiiion o( Ostna i-iiv/iiiicii, known as llic racrcon. "coon," or '• cat's Inngiio" oj-Rti-r among oysternicii, nalnral nIzo. Pig. o — Holh valves of tho foicnoitij^ Hiii'cinion i)lacc, with i!io outor surface of lhi< right va)'o facing tlic observer. »> I .■mt' ■'I 430 I'OSSIL OSTElilUiE OF NORTH AMKKICA. ^'l< PLATE I.XXXII. Three views of the right and left valves of a smaller 8i)eoimen of the raccoou or cat's tongue oyster. 3C 'I i ! I I • « ■^^-