CM "CTi .00 -o ■o -CD CO :<- y > 1. ■'- t^iViaioi'L- V]. .- riXixovv\oWQ w 3 THOR 5kSEl ■^^^ NEW T"' & FU' .LL & tLiJplCOr \ a^ V. 18 palj:ontology OF N E W - Y 0 R K. VOLUME I. • ■ ' ' ■■ CONTAINING DESCRIPTIONS OF THE ORGANIC REMAINS OF THE LOWER DIVISION OF THE NEW-YORK SYSTEM, (EQUIVALENT OF THE LOWER SILURIAN ROCKS OF EUROPE.) BY JAMES HALL. ALBANY : PRINTED BY C. VAN BENTHUYSEN. 1847. (,(^'^' ■^^'*l? 'VL The copyright of this work is secured for the benefit of the People of the State of New- York. SAMUEL YOUNG, Secretary of State. Albany, 1843. , * A TO Ills EXCELLENCY SILAS WRKiHT. fiuvfiiior of tlie Sliile of i\tw-\ork. SIR, I HEREWITH submit tlial part of my Report on the Palaeontology of New- York, containing descriptions of the organic remains found in the lower division of the system, which comprises the Potsdam sandstone, Calcifcrous sandstone, Chazy limestone, Birdseye limestone, Blaclc-river limestone, Trenton limestone, Utica slate and Hudson-river group. All the species described will be illustrated by figures drawn and engraved from original specimens, the greater part of which have been collected by myself from these strata, and the others received from individuals whose authority for their geological position will be cited. 1 Ikivc tlic honor to Ijf, With gie;i( rcsi)ect, Your iihcilu'lll scrvaiil. JAMES HALL. Albany, Septenibet 1, 1849^ ■f 0 CONTENTS OF VOL. 1, Preface, Introduction, Organic Kemains of the Potsdam sandstone, ' — — ' Calciferous sandstone, — — Chazy limestone, — — Birdseye limestone, -^ — Black-river limestone, — — Trenton limestone, — — ^ Utica slate and Hudson Additions and Corrections, Organic Eemains of the Taconic system, Tabular List of Species, List of Plates, Pages. ix - xiv XV - xxiv 1 - 4 •5 - 13 14 - 36 37 - 46 46 - 60 60 - 249 oup, 2o0 - 314 . 315 - 318 . 319 - 320 321 - 333 334 - 333 PREFACE. The present work was committed to my charge in the spring of 1S43 ; but the wnfinished state of my Report on the Geology of the Fourth District rendered it impossible to devote myself entirely to the Paheontology, during the remainder of that year. From the limited time at first allotted to the completion of the work, it became necessary to examine cursorily all the sti'ata of the system, with a view of giving several representative species or typical forms of each group. This plan was continued until the end of the year 1844 ; at which time I had materials prepared for a single volume, to be illustrated by about 70 plates, giving figures of fossils from all the strata ii-om the Potsdam sandstone to the Coal formation. I then became satisfied that such a work would afford but a very imperfect and incomplete re- presentation of the extensive and rich fossiliferoxts series of New- York. In consideration of this circumstance, the time originally contemplated for completing this work Avas extended by the Legislature at the session of 1840 ; and I commenced a re-examination of the lower strata, with a view of giving a more complete representation of their organic contents. The result of these subsequent investigations has more than doubled the number of species at that time known to me, and has increased the plates from 40, the number originally contemplated for illustrating these groups, to more than 90. In the present volume, I have, in many instances, given much detail in regard to surface and internal structure, changes of form resulting from age, nature of sediment, and other circumstances. To geologists and paleontolo- gists, already acquainted with these facts, some portions of this may appear unnecessary ; but it should be remembered, that of the 3000 copies printed, probably 2500 will go into the hands of persons unlearned in any department of natural science. The work is published expressly for the benefit of the people of the State of New-York; and I have, in this diflicult subject, en- deavored to point out to the apprehension of all, the differences of character, I Pal.eontology. I B PREFACE. Avhich, from being overlooked, have often led to the confounding of species from different strata under the same name ; and I have also endeavored to show how important, in some instances, are very slight differences. At the time this Avork Avas commenced, about seventy species were accurately known and described from all the strata of the lower division of the system. This number is already more than quintupled, and new forms frequently come under observation, showing that this part of the palreozoic series furnishes its full proportion of fossils. The niuiiber of species and A'arieties already described amounts to 381 ; * and among these we shall observe a proportion of the different classes and orders, not materially varying from other and younger portions of the palaeozoic series. Free from preconceived opinions regarding the geological range of species, and Avilling to find identical species in rocks widely separated, I have been surprised at the result of my investigations in the lower strata, which thus far have not produced a single species that can be satisfactorily established as common to succeeding formations. There are two species, concerning which some doubt may remain : these are the Leptana tenuistriata, and the Cahjmme scnaria ; the first of which is regarded by some geologists as identical Avith L. riigosa, and the latter Avith C. blumenbacliii. There are, hoAvever, some slight differences in the external characters Avhich lead me to question the identity in either case, and to refer them to distinct species. These two in- stances, even if regarded as exceptions to the general rule of the entire extmction of species at the termination of any great epoch, form so small a proportion of the Avholc, that they ofler very slender grounds for generaliza- tion. The geological .structure and order of succession among the strata of this period had ah-eady been clearly made known in tlie Reports of Messrs. Vanuxem, Emmons and Mather, avIio have also given many of the typical fossils. The greater number of species previously known Avere described by Mr. Conrad, in his Annual Rcj)orts on the Pakeontology of the State, from 1838 to 1841 ; and in the Journal of the Academy of Natural Sciences of Philadelpliia, Vol. viii, 1842. Several other species were named and described ^n manuscript by Mr. Conrad, some of which Avere published by Dr. Emmons in his Report upon the Second Geological District; and I have been able to • See Table at the end of this volume, page 330. PRKFACE. identify some additional ones from Mr. Conrad's notes, and from labelled specimens in the State Collection. Ill describing the species, I have preferred to follow the stratigraphical order, beginning with the lowest rock ; considering the geological succession of species to be more in accordance with the design of this work, than a zoological classification. I have nevertheless endeavored, under each rock, to arrange the fossils according to their zoological affinities, beginning with the corals, which are preceded by the marine plants where any are known in the rock. This arrangement has not been so perfc-ct as could have been desired ; but the fiiture volumes will be so planned, by a double series of numbers for the pages, as to admit of being separated, and a complete zoological arrangement of the species made. What we snost need, however, for the purpose of facilitating geological research, is a true representation of the species in their order of succession, arranging always those from separate rocks or groups by themselves. In this manner only can they have their true value affixed to them, and their relative chronological importance assigned. The increased number of species over those before known as belonging to these strata, the larger part of which appeared to be new, has made me diffident in advancing the results of my researches, and in claiming, not only a large number of new species, but also a considerable number of generic forms not before recognized. Since the descriptions of species contained in this volume were prepared, and while the early pages were passing through the press, I have had the rare opportunity of several times consulting M. de Verneuil in reference to this part of the subject. His examinations have led to the same result, and he has encouraged me to publish my species as they now stand, assuring me that the greater part are new, and quite distinct from the published European forms. Subsequently I have had the pleasure of submitting some of my specimens, and the results of my examinations, to the learned M. Agassiz, who has honored me by expressing a favorable opinion of my labors. Although, encouraged by such friendly expressions on the part of able naturalists, I have less anxiety than I should otherwise have felt in the publication of the volume, I am nevertheless fully aware that there is much room for improvement. Of my scientific friends, and of the scientific public generally, I must ask indulgence, while they consider the circumstances under which the Avork PREFACE. has been wrought out. Situated where I can have no recourse to scientific friends except by letter, with a scanty library of works on Paleontology, and no authentic collections tor the comparison of species already described, I have been forced to depend upon my own resources in every department. I cannot therefore but suppose, that those who have devoted themselves to the study of some particular department, with greater facilities than are within my reach, will find many things, which, under better auspices, could have been made more perfect. I can only content myself with having represented in the engravings, as accurately as possible, every object described in this volume; thus aflbrding, to those who desire to do so, the means of com- paring species, and of correcting any erroneous references. I must here acknowledge my obligations to my friend James D. Dana, Avho has given me some valuable suggestions in regard to the corals ; and had it been possible to do so, I should have submitted the whole of this class of fossils to his examination and decision. I am indebted to many kind friends for specimens loaned or given to me for this work. I have received many fine ones from Dr. I. B. Crawe of Wa- tcrtown, Jeflerson county ; from Dr. Budd and Mr. Ai,son Clarke of Turin, and from Mr. Luke Wilder of Lowville, Lewis county. I am under obligations to Gen. Spinner of Mohawk, for several fine speci- mens from the lower strata, and for others from a higher position which do not appear in this volume. I am likewise indebted to Mr. W. H. Pease of New- York, to Mr. Lyman Wilder of Hoosic-falls, and to Dr. A. J. Skilton and Prof Cook of Troy, for numerous specimens, some of which are already cited in this volume, and others will be given in the succeeding one. Mr. John Gebhard junior, of Schoharie, has allowed me the free use of his valuable cabinet, which has furnished several fine specimens for the present volume, and will be of the most essential importance in illustrating the middle and higher groups. 1 am greatly indebted to the late Mr. Wadleigh of Middleville; and the extensive collections purchased from him have enabled me to present many new forms, as well as to illustrate in a much more perfect manner others not contained in my previous collections. I should not omit in this place to make my acknowledgments to my col- leagues jNIr. Vanuxem and Dr. Emmons, who have both fiirnished me with PREFACE. Xin specimens not in my own or the State collection. To several other persons my obligations arc also due in particular instances, which are cited in the body of the work. Dr. T. li. Beck, with his characteristic liberality in matters of science, has allowed me free access to the collection of the Albany Institute, which contains many valuable and unique specimens. I have cited, nndcr the descriptions, several specimens figured from this collection, and I shall be tiirthcr indebted to the same for materials for the next volume. To my friends out of the State, who have furnished me with specimens from the same formations, for comparison with those of NcAv-York, my especial thanks are due. Among these I may mention Messrs. Joseph Clarke, J. G. Anthony and S. Carly of Cincinnati, and the Rev. Mr. Christie of Oxford, Ohio, who have liberally forwarded to me many valuable specimens, by the aid of which, in many instances, I have rendered my descriptions and illustrations more complete than I could otherwise have done with the specimens from New-York alone. Among the species described and figured, are a few which have not yet been obtained in the State of New-York, but which may hereafter be re- cognized, as more careful investigations are made in the same strata. These species are so intimately associated with others which are well knoAvn and abundant in this State, that I considered it desirable to represent them in their true place. Since this volume has been printed, the Legislature of 1847 have, with munificent liberality, passed a law for the completion of the work, and have authorised 250 plates to be engraved. This number, judging from what I already know of the succeeding strata, will be sufficient for ample illustration of the entire series. The succeeding volume will contain the descriptions and illustrations of the fossils of the strata, from the Hudson-river group, up to the Oriskany sandstone inclusive, and will appear in the course of the ensuing year. The remainder will follow as rapidly as may be consistent with accuracy in the determination of their specific characters and geological relations. In the mean time I shall embrace every opportunity of adding to the present portion of the work, by arranging materials as they may come to hand for sup- plementary plates. I shall therefore feel under great obligations to any friend PREFACE. who may have it in his power to furnish me with species from the lower rocks, not here described, or who can aid me in obtaining specimens for the better ilkistration of those species but imperfectly represented in the present plates. Many of the difficulties attending the preparation of this work thus far, are entirely or partially removed ; and I confidently anticipate being enabled to bring forward the succeeding parts of it more rapidly, and, so far as regards the artistical part, in a manner more satisfactory to myself and the public. The succeeding strata are better known, and more extensive col- lections have been made from them ; and there are also more numerous localities, and better exposures of the strata. I shall also be able to avail myself of the results of previous labors in the Fourth Geological District, Avhere I have already carefully studied the strata and their contained fossils. The increased number of species from the lower strata, resulting from my investigations since 1844, and the consequent expansion of the volume, has compelled me to omit the plates already prepared for illustrating the suc- ceeding strata, which were engraved in 1843 and 1844. From the same cause, the sketch of the geology of the State, which I had proposed to precede the descriptions of the fossils, has been deferred, and Avill appear in a succeeding volume, accompanied by descriptions and figures of the principal genera of palaeozoic fossils. In conclusion, I wish to express my obligations to Mr. John Paterson, who has had the entire direction of the typographical arrangement of the volume, as well as the correction and revision of the proofsheets. I have also been indebted to his literary and scientific knowledge, for the general accuracy of the work. INTRODUCTION. TiiF, publication of (lif Final Reports on the Geology of the State of New-York made known, in a very satisfactory manner, the true oriler and sequence among the strata, from the older crystalline, or azoic rocks, to the Carboniferous system. The subdivisions then proposed had been wrouglit out with much care, and though in their main features based upon lithological characters, had nevertheless been studied in reference to their fossil organic contents, and eacli group was illustrated by a few typical species. Still it remained to ascertain more conclusively whether the divisions proposed were, in all cases, important and distinct groups, characterized by an assemblage of fossils sufficiently numerous and constant to be reliable over wide areas, and under considerable lithological variations. With this view, the study of the palaeozoic features of each group has been pursued with attention ; and though the entire series is yet incompletely made out, there is still enough known to prove more conclusively the propriety of retaining tlic subdivisions heretofore established. In proposing the groups at that time adopted, and imiting the whole series of strata as a, single system, it was not for want of means of distinguishing tlie limits of the more impor- tant subdivisions. The entire succession was regarded as forming a series intimately linked together by the nature of its organic contents, and showing no very important changes, till we arrive at the base of the Old Red Sandstone. It is true, we found no difficulty in recognizing, in a general manner, the subdivisions of the Silurian system, and also, in the higher part of the series, a large number of fossil species identical with Devonian forms. Still, if we are to admit among species of Silinian date, those forms from our Hamilton group, so analogous, and in several cases identical, witli tiiose of (lie Ludlow rocks of England, it becomes impossible to recognize, as distinct from these, any Devonian rocks. Indeed we find the species liere alluded to, so mingled with others of Devonian character, that we are forced to admit the whole as belonging to the latter sj-stem. Tracing the suc- cession downwards, also, from this latter point, we find, in tlie organic contents, no evidence of a change of sufficient importance to indicate the commencement of another great division of the system, till we pass below all those rocks (the Corniferous and Onondaga limestones) charged with Favosites, CyathophyUi, and other forms, of which many appear to be Xvi INTRODUCTION. included in the Wenlock formation of England. Passing upward, on the other hand, to the red sandstone, containing remains of peculiar fishes so analogous to those of the British Isles, that wc unhesitatingly refer the rock to the Old Red Sandstone of Europe ; we find the formation separated by an unequivocal line of demarkation from the rocks below, which are charged with shells and trilobites. So abrupt and well defined is this line, that in undisturbed regions we have no difficulty in recognizing it by the sudden and entire cessation of brachiopods alone, while usually the lithological change is more distinctly marked by a coarse sandstone or conglomerate. Whatever may be said, therefore, of the identity in age, and the mingling in the same formation, of Devonian fossils, such as Brachiopoda, Acephala and Gasteropoda, with the peculiar fishes of the Old Red Sandstone in Great Britain, such a condition never happens in the United States, so far as observations have extended.* At the present time, I am obliged to recognize the following great subdivisions as in- dicated by zoological characters. Commencing with the lowest rock known to contain fossils, we find the first important change in the typical forms to occur at the termination of the Hudson-river group ; which is marked by a coarse sandstone or conglomerate (the Oneida conglomerate or Shawangunk grit), beyond which scarcely a single species has prolonged its existence. This point amst be considered as representing that horizon, which, in Great Britain, is the termination of the Lower Silurian deposits. We never find, however, in the succeeding groups, a mingling of the fossils of the lower and higher rocks, which is regarded as taking place in England and Whales, where the strata are much disturbed. Tlie Pentamerus ohlongus, so well known and extensive in its geograpliical range, is never found in the United States associated with the fossils of tire lower division. On the other liand, it occurs in a calcareous band among shales and sandstones, far more naturally belonging to the succeeding higher strata than to the lower. Moreover, although found in • In the State of New-York, and in other parts of the United States, the most natural and obvious arrangement would be to include in one system all the strata to the termination of the Clicmung group ; since, as already shown, there is no lithological change more obvious or important at tlie liase of these higher formations, than there is at the base of the Niagara and Clinton groups. Where the Oriskany sandstone is absent, it is even scarcely possible to distinguish the line of separation between the Niagara and Corniferous limestones, though one is regarded as of Devonian and the other of Silurian age. If we consider any one class of fossils a-s a guide in determining the limits of systems, then perhaps the peculiar " Devonian fishes," which first appear in our Schoharie grit, or at,the base of the Onondaga limestone, will be regarded as indication of the commencement of a new era. Still, however, the characters of the other classes of fossils is not materially changed, and several species of the central part of the system have prolonged their existence into the superior strata. The zoological question, therefore, is to be tested upon the ground, whether the commencement of a certain order of fislies at a certain period is more important than the subsequent change, when all the other classes of organic remains are exterminated, and the same order of fishes is continued ? INTRODUCTION. XVII a lower calcareous band, it cannot be separated by any important liiliological or zoological characters from a succeeding ono, in wliich we find fragments of Bumastis harriensis, and other fossils typical of the middle division of our system. Indeed, so well marked is the position of this fossil, that throughout a large part of Nuw-York, and at intervals in a western direction, extending even beyond the Mississippi river, it holds its unequivocal place in the series ; never mingling with the abundant lower forms, nor rising far above uted. Of the latter genus, however, two species, the A. modesta and A. increbescens , are abundant and widely distributed, being every where typical of the lower division of the system. So few species of Acephala from this period have been described in Europe, that no very satisfactory comparison can be drawn between them and our own. We recognize, nevertlielcss, several forms very analogous to those of New-York and the Western States. In this class I have established several new genera, among which are the Modiolopsis, Ambonychia and Tellinomya : the two former of these are well characterized in several species, while the latter now embraces some that are probably heterogeneous forms.* These may be regarded as palaeozoic genera, and the species thus far indicated are im- portant in distinguishing the older strata. The number of species of this class is far greater than could have been aiuicipated, being more than half as many as of the Bracliiopoda, and are therefore entitled to our consideration. Among tlie Gastroi-ods, there is a very close resemblance in several species; while among those which appear to be identical with European forms, we are able to assert positively only one or two of which no question remains. f In this class, we have several genera peculiar to Lower Silurian strata. Among tliese may be included Ophilcta, Raphi- stoma, Scalites, Madurea, Bucarda and Cyrtolites. The species in this class, although juuubering several genera, are not numerous till we arrive at the base of the Trenton limestone. The generic form Bucania, wliicli I have separated from forms licrelofore re- ferred to Bellerophon, we now know to belong to an earlier period, and is represented by two distinct species some time anterior to the appearance of the latter genus. ' The condition of these fossils is such, that often liHlc more than the form can be ascertained ; consequently it is difficult to give reliable generic characters, since form is often so variable in species of the same genus. By examining the descriptions and figures here mentioned, the reliable characters of these genera will be ascertained ; and since they are the earliest forms constructed upon this type, they are worthy of consideration, inasmuch as we regard it important that the earliest forms should in all cases be regarded as typical species of the genus. t If the figures and descriptions of Euomphahis qualteriatus and Murchisonia gracilis are correct, our species, which have been referred to these, are (juite distinct. INTRODUCTION. XXI The Cephalopods appear among the earliest organisms, two species occurring in the Calciferous sandstone. Though appearing in all the succeeding strata, they are not nu- merous in the Chazy and Birdscyc limestones, but are the most conspicuous forms in the Black-river and Trenton, both of which may with propriety be termed " Orthoccratite limestones." The lower division of the system is pre-eminently the era of Cephalopods of the order Orthocerata ; and even throughout the entire palfeozoic series in the United States, no subsequent formation affords so great a development in any of the other families of this class. The several new genera of these fossils are founded on peculiar characteristics, indicating, indeed, in one instance, even more than a mere generic distinction. We have a sufficient number of Trilobites, identical with those of the Lower Silurian rocks of Europe, to institute a comparison of the conditions of the ancient ocean in both hemispheres. That remarkable and characteristic Lower Silurian form, Trinucleus, is among the most common ; while Illcenus and Isotelus, no less characteristic, are obtained in the earliest limestone. Several new species have been added ; while others, hitherto but im- perfectly understood, have been more fully illustrated. It is not a little remarkable, that at this early period we have the representatives of nearly all the important genera of Tri- lobites known in our palaeozoic strata. Thus far, no remains of Fishes, or other animals of a higher order, have been dis- covered ; though we find them almost at the commencement of the next division, and in all the succeeding paleozoic strata. The results of these investigations in the lower formations, though necessarily very imperfect, have nevertheless shown a comparatively equal or proportionate development among the different classes ; and though certain forms appear often to Iiold a predominance, it is frequently due to the development of a greater number of individuals, rather than the number of species. In other cases, the species of certain genera are more numerous, while in a succeeding rock the order may be reversed. This is true in regard to the Brachiopods, Avliere the terebratuloid forms increase in the higher rocks, and predominate greatly over Orlhis and Leptcena. The Ortlioceratites diminish in number of species, and individual preponderance ; while forms like Cyrtoceras and Goniatites, which are rare in lower rocks, become the predominating genera of this class in the higher strata. Among the Corals, the Cheetvtes of the Lower Silurian strata gives place to Favosites, which flourishes in abundance. All the Cyathophyllidea of the lower division of the system, having turbinate forms, are destitute of transverse or horizontal septa ; * and the first • The two species, Columnaria alveolata and Favistella stellata, have transverse as well as vertical septa ; but these forms, though regarded as belonging to the same family of Corals, are so dilVerent in their habit and mode of growth as to appear more nearly allied with Favosites. T Xxii INTROCUCTIO^f. species in which this character is developed, has the depression on one side, as in Caninia. Indeed, admitting the subdivisions among the groups as proposed, we shall scarcely find a well characterized species of Cyathophyllum in Silurian strata. Of the other families of Corals, or the Brj'ozoa, less is known, but there are nevertheless some important differences in character in the ascending development. Passing over the intermediate classes, I have noticed, in the Orthocerata, some pe- culiarities of structure which appear confined to species belonging to the lower division of the system. The first of these is in the undulating septa and angular form of Gonioceras ; which is the first instance, within my knowledge, of undulating septa in a straight cham- bered shell of palaeozoic date. The singular internal structure exhibited in the Endoceras, showing in fact the viviparous character of the animal, is still more remarkable, and exhibits a feature in the physiology of these animals before unknown. The great numbers of specimens examined leave no doubt of the true nature and object of this peculiar de- velopment of the siphuncle, which embraces the embryo sheath. I regret to say, however, tiiat I have not been able to make investigations to such an extent as would enable me to ascertain the true characters and gradual development of the young shell as it is found in the embryo sheath, and subsequently in its free state. Thus far, I have not discovered in my collections a single species having this character, from any strata above the Hudson- river group. The peculiar character of siphon observed in Ormoccras, I am induced to believe, is also found in one or more species in the higher strata ; but of this I cannot yet be entirely certain. This brief introductory notice can scarcely be regarded as more than a slight and im- perfect sketch of the subjects introduced. Suflicient progress has not been made, to speak with confidence of every point. So many new developments have taken place in the course of investigation, that we arc ready to expect others in our future progress ; and although these may not essentially modify general results, they may nevertheless tend to give greater force or importance to some minor points, or to show more clearly the untenability of others. The plan of the work, as has already been stated, is to give a complete representation of the succession among the organic forms typical of the palaeozoic strata, arranged in the chronological order of those strata. The clear and undisturbed succession which prevails tliroiighout (lie entire series, has given a certainty in the direction and result of our labors ; and it remains only to be hoped that the same facilities in the following portions will give that part of the work an equal value for its accuracy in this respect. INTRODUCTION. XXIll Every step in this research tends to convince us that the succession of strata, wlien clearly shown, furnishes conclusive proofs of the existence of a regular sequence among the earlier organisms. We are more and more able, as we advance, to observe that the Author of nature, though always working upon the same plan, and producing an infinite variety of forms almost incomprehensible to us, has never repeated the same forms in successive creations. Tiic various organisms called into existence, have performed their parts in the economy of creation ; liave lived their period, and perished. This we find to be as true among the simple and less conspicuous forms of the palaozoic series, as in the more remarkable fauna of later periods. The truth of all these conclusions is now so well sustained by ihe results of scientific investigations, that we regard the history of the past, from the dawning of vitality till man assumed the dominion over tlie whole, as marked in certain and intelligible characters, incapable of misinterpretation. ^H. PALiEONTOLOL'V OF NEW-VORK. POTSDAM SANDSTONE. Tins rock, with its associated slates and conglomerates, we regard as lying at the base of the palaeozoic strata; as having been produced at the dawning of the vital principle upon our planet, forming the eozoic point in our series. Nothing which bears the semblance of having been organic is yet known in strata of anterior origin. If, as has been supposed, organic forms were enveloped in the materials of the gneiss, mica and talcous slates, they have been so far obliterated by supervening changes that they cannot now be recognized. Neither has it been demonstrated, except to a very limited extent, that any of these rocks are of origin anterior to those which we term palaeozoic. In the metamorphosed strata of more recent periods, we are able to trace the gradual extinction of the outlines and substance of numerous organisms as we pass from the unaltered to the mctamorphic condition of the same formations. Therefore, in strata like those of the gneiss and associated slates, where the present character departs so widely from what we suppose to have been their normal type as sedimentary rocks, we are scarcely justified in expecting to meet with organic remains which might give a clue to their geological age. It can only be by a thorough study of the structural development, that we can hope to arrive at satisfactory conclusions regarding the age of a large portion of the metamorphic strata on the cast of our fossiliferous masses of the Hudson River valley.* • Some months since, Prof. H. D. Rogers informed me that he had discovered palaeozoic fossils in the White Mountain range ; and while this part of my report was passing through the press, I read the paper of Profs. H. D. and W. B. Rogers, "On the geological age of the Wfiite Mountains." It would appear, from the fossils discovered, that these apparently ancient and highly crystalline strata are of the age of the Clinton group of New-York. Never- theless, I am, for various reasons, inclined to regard the association of fossils there mentioned, though necessarily obscured by igneous action, as indicating the occurrence of the Hudson River rocks, which we find extending to a considerable distance east of the Hudson River, charged with Lingiilte, Cytherinir, Jignosti, and fragments of other Crustacea. I have already shown (Transactions of the Association of Geologists and j\"aliiralists, A'etB-Haven, May 1S45), that the Shawangunk grits do overlie the shales of the Hudson River group in Rensselaer county, N. Y., occupying some deep folds of the strata beneath. The same gi'its and conglomerates may be seen again farther to the north in Vermont, capping the summits of some of the elevated ridges ; and, so far as we can discover, these coarse grits are conformable to the strata beneath. [Paleontology.] 1 2 PALEONTOLOGY OF NEW-YOKK. We shall therefore commence our descriptions with those organic forms which are typical of the acknowledged base of the pala-ozoic series on the American continent, leaving for future consideration those forms Avhich have given rise to some difference of opinion regarding the age of the rocks in which they occur. Further explorations may add to the number of forms already known in this rock ; but it must be acknowledged, that, thus far,, it has proved very barren in organic products. ORGANIC REMAINS OF THE POTSDAM SANDSTONE. Plate I. Genus SCOLITHUS. [ From the Greek, rfx^Xrig, a worm, and Xiflo?, a stone.] Skolithus. Haldemait, Supplement to No. I. of a Monograph of tlie Limniades, &c. 1S40. This name was first proposed by Professor Haldeman, as forming a sub-genus under FucoiDES, and is now recognized by him as forming a distinct genus. Character. Stem free, simple, cylindric or subcyiindric, vermiform or linear, never branched. 1. 1. SCOLITHUS LINEARIS. Plate I. Fig. 1. a. b. c. Stem simple, rectilinear ; surface nearly even, cylindric or compressed, sometimes apparently striated. Diameter ^ to ^ an inch ; length from a few inches to several feet. This fossil, in its usual aspect, presents the appearance of numerous linear stems, often extending to one or two feet in length. Ordinarily it appears like a series of small pins or pegs driven into the rock in a somewhat regular manner, and at uniform distances. It preserves its distinctness even when the surrounding rock is much altered, as along the western face of the Green Mountains. In such situations, and often in others, the fossil is stained by oxide of iron, and the rock cleaves more easily in that direction. In tlie Second Annual Report of the Geology of Pennsylvania, Prof. Rogers speaks of this " marine plant " as the best defined species discovered in this rock. He has also spoken of it under th(> name of Tubuliics ; but I believe no generic description ever appeared, previous to the one of Prof. Haldeman ; nor am I able to find in print tlie name tubulites applied to this fo.ssil, of anterior date. Fig. 1. a. A vertical or longitudinal view of a specimen of the rock containing these bodies. Fig. 1. A. A similar view of a specimen of partially altered and laminated sandstone from Pennsylvania, the tubes somewhat flattened. Fig. 1. c. Weathered surface of a specimen of the altered sandstone (crystalline or granular quartz), from Adams, Mass. POTSDAM SANDSTONE. d Position and localities. This species is apparently confined to tlie Potsdam sandstone, though usually uuassociatod willi any otluT Ibssil. It is found, though somewhat rarely, in the valley of Lake Chaniplain ; and it also appears in the jjartially altered sandstone of the same age, at the base of the Green Mountains, in Adams, Mass. Rolled masses of the same rock, containing this fossil, are not unfrcquent in the eastern part of New- York. It occurs in the same sandstone in several localities in New-Jersey. In the sandstone of the same age on the Susquehanna, and at other places in Pennsylvania, this fossil is of frequent occurrence ; and it may be traced in the same rock, through Maryland and Virginia, to Tennessee. , {State Collection.) Lingula prima. Conrad. 2. 1. LINGULA PRIMA. Pl. I. Figs. 2 a, b. Obtusely oval or rounded, short, obtuse at both ends ; sides curved ; base rounded ; beak scarcely rising above the margin of the shell ; surface marked by faint concentric lines and sometimes a few concentric wrinkles, and fine longitudinal stria-. In some specimi-ns, the concentric and longitudinal striae are equally distinct, while in others the longitudinal strite are more distinct. In its form and general aspect, this shell bears considerable resemblance to L. carta of the Trenton limestone and Utica slate ; but that shell is usually larger, less obtuse at the beak, with strong concentric stria;, while the longitudinal ones arc indistinct or obsolete. Position and localities. This fossil is for the most part rare even in the Potsdam sandstone, though at Keeseville in Essex county it is quite abundant, forming distinct laminie in the rock, like films of carbonaceous matter. It extends, according to Dr. Emmons {Geol. Rep. p. 268), through a thickness of seventy feet of the rock at this place. It occurs also at Rosse's biidge, four miles west .of Essex village, Essex county. (State Collection.) 3. 2. LINGULA ANTIQUA* (n. sp.). Pl. I. Figs, 3 a, b, c, d, e. Elongated, subspatulate, rapidly tapering towards the beak ; sides usually straight, sometimes abruptly curved ; front broadly rounded ; surface marked by concentric lines ; no visible longitudinal striaa. * The figure given by Prof. Emmons {Geological Report, p. 2CS) as Lingula antiqua of the Potsdam sandstone, is the L. acuminata (Conr.\d, Annual Report «/lS39, p. 64) of the Calciferous sandrock, and is not known to me as a fossil of the Potsdam sandstone. The original specimen from which the figures were taken, in the collection of Mr. Vajsuxem, bears a close resemblance to L. attemeata of Murchison's Silurian System, p. C41, pl. 22, fig. 13. 1* 4 PALEONTOLOGY OF NEW-YORK. This shell is somewhat variable in form, as represented in the figures ; but the apex ia uniformly acute, and the surface of the shell marked by concentric strife. It approaches in form to tiie L. acuminata of Conrad ; and I am unable lo point out the difference, having only a drawing of that shell. In many cases, this shell, in the Potsdam sandstone, is almost wholly absorbed, a mere film remaining, showing the form of the shell. By taking extreme forms of this species, since the shell is so obsciue, it would not be difficult to indicate two^ distinct species. Fig. 3 a. The usual form of this fossil. Fig. 3 A. A broader specimen, with apex wanting. Fig. 3 c. A very broad somewhat rounded spfcimen, a viewof the interior of the shell, the inner laminae- waniing, and the concentric elevated lines showing in rehef. Fig. 3 d. An elongated specimen, somewhat compressed laterally. Fig. 3 e. An enlarged portion of 3 c. Position and locality. In the grey friable variety of this rock in the town of Hammond,, St. Lawrence county, and near Alexandria landing in Jefferson county. (State Collection.) We look upon these minute fossils with no ordinary degree of interest, as having been,. for a long period, almost the only representatives of animal life, at least upon this portion of our globe.* We find other species of the same genus in nearly every group in the New- York system, while others have flourished in every geological period, and many are still living in our present seas. In opposition to very conmionly received notions, we here find, as the earliest representative of the animal race, species of a still existing genus, showing that the conditions of tliat primeval ocean were in many respects similar to our own. We see, so far as the evidence goes, that external conditions were then as favorable to this form of life as at present ; and though subsequently immense numbers of forms were called into existence, differing from I he common and numerous forms of the present day, still, since some similar forms do occur during all this time, we arc justified in supposing that the conditions iheii existing were not very dissimilar from those at the present lime, where such forms now flourish. The form of these Lingidcc scarcely differs from that of some of the modern or existing species, showing that through all this time nature has worked upon the same principle in the production of her works ; and the little shell of modern seas is produced, in form and appearance, and in action and h;d)it, like tlie little shells which flourished in the earliest era of life upon this globe ; a period so incalculably lost in the [jasl, that we can have no conception of the time that has elapsed between. * Prof. H. D. Rogers has informed inc tlui' he bclipvcs he ha.s obtained a species of Orbkuhi from this rock, thu.i adding a third species, all belonging to genera whicli flourished in nearly eveiy subseijucnt period, and of which species still exist. Mr. Lyell also remarks that he obtained at Kecseville a placunoid fossil associated with the IJngttla {Travels, p. 132). CALCIFEROHS SANDSTONE. CALCIFEROUS SANDSTONE. Wo find in this rock, in niiincrous localities, a great nnmlier of what appear to he the remains of sea plants. Many of these consist apparent!}' of fragments of large succulent stems, even giving some evidence of having been hollow, like the stems of some of the marine plants of the present day. It is impossible in these, as in nearly all the remains of marine plants of the paheozoic rocks, to detect any structure which can be reliable in making distinctions. In the case before us, we are led to refer these vestiges to marine vegetation, not from their appearance a'one, but fiorn the fact that wtrfind, in cavities of the same roclc, small quantities of anthracite. Now although the present condition of this carbonaceous matter is that of antliracite, we nevertheless believe it to have been a fluid or semifluid bitumen, from the fact that where occurring free in a cavity of the rock, it has indurated in a globular or semi-globular form, indicating a degree of fluidity in its original condition. The very natural suggestion is, that the bituminous matter derived from this vegetation has parted with its volatile parts, and become a solid mass of non-bituminous coal. Whatever weight such an argument may liave, we cannot resist tlie inclination to associate this production with the obscure remains wliicli we find in the same strata. From the nature of the rock, and from the condition of many of its fossils, w'e cannot doubt but many more forms, both of plants and animals, were imbedded in it, than we find at the present time. The very obscure impressions and cavities which so frequently occur, in some of which it is not difficult to detect the marks of organic structure, lead us to believe that the sea from which this deposit was thrown down contained a numerous fauna. That their remains are so obscure at the ])resent time, has doubtles arisen from two causes : first, that during the deposition of the mass, there was a considerable intermixture of silica, which to some extent existed in a soluble condition, and, as we infer, absorbed the exuvia; and obscured the characters of these remains ; and again, the proximity of this rock, in its best defined localities, to those of hypogene origin, and the nmiierous faults and uplifts it presents, lead us to believe that it has undergone subsequent changes, which also may have had some effect in obliterating the organic forms. In nearly all instances, we find the shells removed, and siliceous casts of the interior only remaining. In a few instances, the siicll is replaced by siliceous matter. Many of these casts are imbedded in a mass of chert or hornstone, tlie material of which has doubtless been aggregated around them after their death, forming nodules or accretions as in the higher.limestones and in chalk. During the progress of this formation, and towards its close, a considerable number of forms of animal life appear to have been called into existence. We have passed from that t) PALEONTOLOGY OF ?{EW-YORK. condition of the earth unfavorable to animal development, and we perceive the gradual change, which, in the next period, presents us with swarms of animated existences. If we can, in imagination, allow ourselves to go back to the preceding epoch — to fancy the earth enveloped in one waste of ocean, save perhaps a few rocky peaks ; when the natural agitation of the waters by the winds was increased by volcanic or igneous outburstings 5 while the rocky points were abraded, and thence fine sand and pebbles spread over the bed of the ocean, we behold life, struggling into existence in this stormy period, only manifested in the fragile yet enduring form of the little Lingula, while an apparejitly rootless leafless plant is the representative of the vegetable kingdom. Look forward from this period to a gradual change — a more congenial element to the inhabitants of the ocean comes, in the form of calcareous matter, and new organisms are gradually called into existence. Still the heated waters bear their burden of silex in solution, and now they permeate every portion of this habitation of the newborn vitality, destroying the living, enveloping the dead in a siliceous paste, and preventing that development of numlicrs which awaits only a more congenial condition. Such, indeed, we have every reason to believe, was the state of things at this period. Numerous hot springs, bursting out from fissures or faults of the lower strata, penetrated with their heated waters the lower beds of this rock during their deposition, and while in a condition to be so affected. The superincumbent waters doubtless partook in some degree of this condition, and became a less congenial abode for the testaceous tribes just called into being. Still this condition does not seem to have been unfitted to the development of the singular vegetable forms which appear in great numbers, and which constitute a large portion of some thin layers (the fucoidal layers) near the base of the formation. The first metagenic interval lies between the deposition of the rock previously noticed, and the termination of this one, and may be regarded as the interval in which certain conditions were assumed by the elements, favorable to those forms of life, which continued through a long period, even indeed to the close of the palaiozoic epoch. CALCIFEROUS SANDSTONE. 7 FOSSIL PLANTS OF THE CALCIFEROUS SANDSTONE. Plate IIv Genus P A L .^ 0 P H Y C U S . [ Greek, *aXaiof, ancient, and (puxos, a seaweed ; from the apparent habit of the plant] Character. Stem terete, simple or brnnchecl, cylindric or subcylindric ; surface nearly smooth, without transverse ridges, apparently hollow. 4. 1. PALiEOPHYCUS TUBULARIS (n. *;;.). Pl. II Figs. 1, 2, 4 and 5. Stem cylindric, gradually tapering (sometimes to an obtuse point as in fig. 1) , unevenly bent or flexuous, irregularly branched and sometimes regularly bifurcating ; surface nearly smooth ; stems and branches usually compressed, and, when weathered, appearing as if hollow. Fig. 1 is a collection of flattened flexuous stems, which were apparently broken and thrown together upon a surface of sand, and gradually covered with shaly matter. The forms are not so well defined as in soine of the other specimens. Fig. 2 is better preserved, and the cylindrical form of the stem better defined. A great number of small fragments occur on the same specimen, some of which present an ap- pearance as if originally possessing a vesicular structure. The small branches appear to have been solid, and the larger stem hollow. The fossil is calcareous. Fig. 4 is a portion of a single stem, presenting a small branch below, with a bifurcation above. This specimen is but partially calcareous, with a considerable intermixture of oxide of iron. Fig. 5 is a collection of fragments of stems, aggregated in a fine sand from the lower part of the formation. It is not improbable but a further examination will enable us to distinguish two species among those described, as the specimens jjresent some diversity of character, which I have attributed to the nature of the matrix, and the variable proportions of siliceous and cal- careous matter. Position and locality. These fossils are more abundant towards the upper part of the mass, and in situations showing an admixture of calcareous matter. Tliey occur in the same layers with the fossil shells in some places, while in others they hold a higher situa- tion than some of the shells. They are found at numerous localities along the Mohawk valley, the principal of which are Amsterdam ; opposite the village of Fort-Plain ; along the railroad ; Canajoharie ; west of Palatine bridge, and at various other places. (State Collection.) 8 PALEONTOLOGY OF NEW-YORK. 5. 2. PALyEOPHYCUS IRREGULARIS (n.sj^.)- Pl. II. Fig. 3. Stems numLTOiis, cylindrical, iiregiilaily branched ; branches flexuous, diverging ; surface apparently smooth. Tliis species occurs covering the entire surface of large slabs of the sandstone. It is always nuich smaller tlian the preceding species ; its condition is such that no definite structure can be ascertained, nor is it easy to give specific characters which will serve to distinguish it from others. Position and locality. Tliis species occurs in the fucoidal layers near the base of the rock, and lower in position than the last described. It occurs near Chazy, Clinton county, and near Keeseville in Essex county ; also between Flint hill and Amsterdam, in the Mohawk valley. The other species occurring in this rock differs essentially from those preceding, and strictly appertains to another genus, which I propose to name BUTHOTREPHIS. [ Greek, /3u^oTp£"rad, in my possession, I am inclined to think he afterwards referred this shell to the L. attenuata of Sowerby. Having never seen a specimen from the sandstone, I can only give this figure from a drawing of Mr. Conr.\d (the original specimen being now in the possession of Mr. Vanuxem), in the hope of calling the attention of observers to the subject, and, if possible, of obtaining specimens which may be satisfactorily compared. [ Palaeontology.] 2 Liocub ftcomiiuU 10 PALa:0NTOLOGY OF NEW-YORK. Fig. 1. View of the upper side of a large specimen. Fig. 1 a. The lower side of a smaller specimen, showing the broad umbilicus. I regard this species as exceedingly interesting, and as linking by a generic type ( very rare in the lower rocks of this country) the lower, middle, and upper palaeozoic strata. Mr. Mdrchison records three species as occurring in the Llandeilo flags, in England and Wales ; but this is the first and only individual in our lower strata, which I feel warranted in referring to the same genus. Position and locality. The specimens were found in a loose mass of the Calciferous rock, in Saratoga county. The character of the mass, and its association, leave no doubt of the true position of the fossil. {Cabinet of Lyman Wilder.) 9. 1. M ACLURE A SORDIDA (».*;;.). Pl. in. Figs. 2, 2 a. Shell discoidal ; spire not elevated; mouth slightly expanded; surface apparently smooth.. The specimens of this fossil usually appear in a weathered, worn and distorted condition, in the upper part of the rock. From their condition, it is not easy to determine their specific relations. From the circumstance that these fossils always present the oval form exhibited in the figures, Mr. Vanuxem has termed them Ellipsolites ; but a careful examination induces me to refer them to the Genus Macluhea, typical specimens of which occur in the suc- ceeding rock. {State Collection.) 10. 2. MACLUREA MATUTINA (n. s;).). Pl. III. Fig. 3. Discoidal, involute ; spire not elevated ; umbilicus deep ; surface unknown, apparently striated. The fossils in this specimen, as is the case with nearly all the others in this rock, are obscure, both from the character of the rock, before alluded to, and from weathering by exposure. It is therefore with some hesitation that I characterize the two species above ; but as they may be of some service to the student in identifying the mass, and as the fact of their existence is also interesting, we offer them as they are usually seen. The rock in which they occur is litliologically a compact silico-magnesian limestone, which weathers with a greyish brown surface, and attains a coarse harsh structure. In the same rock are often seen a few fragments of Orthocerata, which, with the numerous individuals of the two species here dcscril)('d, render some of the thin layers highly fossiliferous. Position and locality. These fossils are usually found in the higher portions of the rock, at Canajoharie, and other places in the Moliawk valley.. CALGIFEROUS SANDSTONE. 1 1 Genus OPHILETA (Vanuxem). "(Greek, otpis, a snake, and siX-^tos, coiled ; the fossil having the appearance of a snake in coil ] Planorbicular, discoidal ; volutions numerous, slender. Tlie above characters are, drawn from the descriptions of Mr. Vanuxem {Report, p. 36). .1 append the woodcut, showing the forms given by him in his report.* 11. 1. OPHILETA LEV ATA. Pl. III. Figs. 4 and 5. Ophileta levata. Vanuxem, Geological Report, p. 3G, fig. 1. Discoidal ; volutions numerous, slender ; spire not elevated above the edge of the outer volution ; concave beneath ; volutions angular below ; aperture not expanded ; surface apparently smooth. This fossil bears a close resemblance to Euomphalus, to which genus I incline to refer it, since it presents no essentially distinct characters. I have, however, in deference to the opinion of my friend, allowed it to remain under the proposed name of Ophileta. Position and locality. This fossil is not uncommon in the fucoidal layers in the Mohawk valley ; it therefore appertains to the iiigher portions of the rock. The specimens in which it occurs are often finely granular, and sometimes oolitic, containing numerous finely comminuted fragments of other fossils, 12. 2. OPHILETA COMPLANATA. Pl. III. Fig. e. Ophileta complanata. Vanuxem, Geological Report, p. 36, fig. 2. Discoidal, planorbicular ; volutions numerous, very gradually increasing in size from the apex. The specimen figured by Mr. Vanuxem (woodcut, fig. 2 ) preserves a more distinct out- iline than any one I have seen. The specimen, fig. 6, pi. 3, is from the State Collection, and labelled as above by Mr. Vanuxem. I have obtained similar obscure forms from this rock, but it is impossible to define any essential characters. Whatever may have been its original nature, it is quite unsatisfactory at present, and can scarcely be regarded as of much importance as a characteristic fossil. * Fig. 1. Ophileta levata. 2. 0. complanata. 3. A crinoidal plate, associated with the preceding. 12 PALjEONTOLOGY of NEW-YORK. Position and locality. This species occurs in the higlier calcareous layers of this rock, at several places on the Mohawk ; at Canajoharie ; and also in Lewis and JefTerson counties. (State Collection.) 13. 1. TURBO DILUCULA (71. s;).)- Pl. III. Fig. 7. Subglobose; volutions few (about 3), ventricose, rapidly enlarging to the aperture; shell thin? ; spire moderately elevated, obtuse ; width and height of the sliell about equal ; surface 1 This fossil occurs in great numbers in the siliceous portions of the rock, usually in the form of casts, or the cavities made by the shell only are preserved. The specimen figured, with portions of several others, occurs in a coarse siliceous mass, partially decomposed, and containing ramified veins of chalcedonic quartz. Position and locality. This species is found at Middlevillc, at (he locality of quartz crystals ; and also at Littlefalls, Herkimer county. It occurs in the lower and middle parts of the mass, and usually in porous or cavernous portions. 14. 2. TURBO"? OBSCURA ( 71. ip.). Pi.. III. Fig. 8. Subconical ; spire ascending, obtuse ; volutions few ( 3 ■? ) , tumid, gradually increasing from the apex ; height considerably exceeding the width. This shell differs from tlie last in the proportionally greater height, and the more gradual enlargement of the volutions from the apex towards the aperture. The specimen figured occurs in a calcareous sandstone, with several others, more imperfect, all of which are casts, and the surfaces much eroded. Position and locality. This shell occurs in the upper portions of the rock, at Fort-Plain. 15. 1. PLEUROTOMARIA'? TURGIDA (71. j?j9.). Pl. III. Figs. 9 and 10. Depressed-conical ; whorls about 4, tumid, subangulnr, rapidly increasing from the apex; last whorl very large, ventricose, expanded ; height and greatest breadth about equal. This fossil is a rough cast of chert in a coarse siliceous mass of calcareous sandstone, and consequently its characters cannot be very accurately determined. The form of the aperture is very similar to that of Natica. In fig. 10, the upper part of the spire is nearly corroded, and the whole surface very rough ; in fig. 9, the surface is less eroded, though otherwise in a similar condition. Position and locality. This species was found in a loose cherty mass of the rock in Saratoga county. (Cabinet of Lyman Wilder.) CALCCEROUS SANDSTONE. 13 IG. 1. ORTHOCERAS PRIMIGENIUM. Pl. III. Figs, n, II a. > Orlhoccras primigtnia. Vanu-vkm, Geological Report, p. SC, fig. 1. Elongated, terete, gr.iclually tapering to an obtuse point; surface smooth?; section circular ; septa thin, deeply concave, closely approximated, being distant only ^'j the diameter ; siphuncle 1 In Mr. Vanuxem's figure, the septa are represented as about 4 or i the diameter. His specimen presents a longitudinal section nearer the apex than mine, and therefore this difference may be expected. The thin and closely approximate septa are very striking characters, and will probably serve to distinguish this species. The parts usually preserved in this rock are fragments near the apex, indicating that this portion was stronger than the rest of the shell. Position and locality. This species is found in the higher calcareous portion of tiie rock, in the Mohawk valley, near Fort-Plain, and also in a brecciated mass near the same place, in great numbers. 17. 2. ORTHOCERAS LAQUEATUM ( n. sj9.) . Pl. III. Fig. 12. Somewhat rapidly tapering (to an acute point?); surface fluted, or marked by lon- gitudinal angular ridges, with intermediate finer ones ; some faint remains of transverse striae ; section circular. One or two only of the septa are still obscurely visible, regularly arched, but their comparative distance cannot be ascertained. This fragment, being a portion near the apex of the shell, is a part of what has been probably a much larger specimen. Position and locality. The position of the specimen is probably at the upper termination of this rock, and just at its passage into the succeeding limestone. Its locality is uncertain. {State Collection.) In presenting these specimens as the typical fossils of this rock, it is not regarded as by any means certain that they are exclusively confined to it. Since several of them occur near its upper termination, and where the mass becomes more calcareous, it is not im- probable they may appear again in the succeeding rock. The vegetable forms, however, so far as known, do not reappear, being apparently confined to the Calciferous sandstone, and flourishing to its close, but disappearing with the augmentation of calcareous matter, and giving place to the remarkable forms presented on Plates VIII. & IX. 14 PALEONTOLOGY OF NEW-YORK. CHAZY LMESTOXE. The lower part of this rock, which can be seen resting upon the preceding mass, presents an agoregation of fragments of crinoidal remains, corals and shells ; showing conclusively that at this early period the sea was as well fitted for the production and support of living organisms, as at any subsequent period. It is true the species are not exceedingly numerous ; neither was the period of their duration very long. Still it is clearly evident that this portion of the ancient ocean, at least, swarmed with animal life in some of the lowest conditions of organization. In none of the subsequent groups do we find a more perfect crinoidal lime- stone, or one composed in greater proportion of the comminuted exuvia of these and other forms of zoophytic existence. Scarcely even do we find so great a number of individuals of any species, as can be obtained of the Maclurea upon the weathered surface of the stratum peculiar to that fossil. In vain shall we look for similar examples of so large a shell as this occurring in such incredible numbers, that several thousands may be counted in the space of a few rods ; and in no subsequent rock can we find even the Brachiopoda in greater abundance than at this period, when entire strata were composed of them. In truth we are almost led to conclude that this period was more favorable to the rapid development of organization, than most of the sidjsequent ones ; and thus at this primeval epoch, in which we have just witnessed the dawn of vitality, and might have expected a gradual ushering in of living forms, we find ourselves suddenly among myriads of extinct animals of all stages of growth and development. This epoch, like every subordinate one, has its peculiar and typical forms ; forms which appear, thrive, and flourish for a time, and are never seen at subsequent periods ; and although these forms may be fewer in the present than in some other cases, they are nevertheless sufficient for an example on which to base a hypothesis concerning the creation and extinction of the successive races v/hich have existed upon the earth. We find here also some forms which appear to claim an obscure place among their associates, but which become in succeeding periods more prominent and numerous, and therefore better entitled to our consideration. From the interest naturally attached to the forms of this early period, I have figured all that could be decided with accuracy ; leaving, no doubt, others to find a place hereafter. Indeed I think there is scarcely anotiier portion of our series that offers a better field for the palajontologist, than tlie lower limestones which are so well developed along the valley of Lake Champlain, the Mohawk valley, and the Black river. Few .points only have been examined, and these with less attention and less time than .could be desired to present any thing like a complete exhibition .of their fossil contents. CHAZY LIMESTONE. 15 CORALS AND CRINOIDEA OF THE CJIAZY LIMESTONE. Plate IV. 18. 1. RETEPORA INCEPTA. Pl. IV. Figs. 1 a, b. A thin expanded Icaflike coral, apparently composed of branches uniting laterally and often irregularly ; fenestrules oval or sometimes slightly angular, unetjual in size ; branches er reticulations even, roundish, scarcely expanded ; no pores visible. This species presents the common appearance of others of the genus, except that the above fragment shows no axis or central point of expansion, and in this respect resembles a fragment of Gorgonia. In the irregular arrangement of the fenestrules, it differs from any of the species yet noticed. Fig. 1 a. Specimen of the natural size. Fig. 1 b. An enlarged portion of the same. Position and locality. In the semi-oolitic limestone near the lower part of the mass at Chazy, and in a similar limestone near Galway, Saratoga county. 19. 2, RETEPORA GRACILIS ( 71. 5^.). Pl. IV. Figs. 2, 2 a. Expansion slender, diverging ; fenestrules oblong-oval ; branches or interfenestral spaces slender, flexuous, slightly striated ; no pores visible. This species differs from the last in its more slender appearance, the greater length of the fenestrules, and the smaller interfenestral divisions. The crust or expansion is less firm and solid. The nature of the stone almost effectually prevents the discovery of any pores upon the substance of the coral. The rock in which this and the preceding species occur is a semicrystalline greyish limestone, cxliibiting in some parts a tendency to an oolitic structure. Fig. 2 a. Natural size of the fragment. Fig. 2 b. Enlarged portion, showing the form of the fenestrules: Position and locality. This species occurs in the lower part of the Chazy limestone, below the position of the Maclurea gigantea, at the village of Chazy, Clinton county. (Stalt Collection.) 16 PALEONTOLOGY OF NEW-YORK. 20. 1. GORGONIA? ASPERA (m. *j9.). Pl. IV. Figs. 3 a, 3 4. A fragment of a leaflike expansion, consisting of an open network ; fenestrules angularly oval, distinct ; longitudinal ribs direct, undulating, united by smaller transverse bars ; surface of the ribs and bars marked by elevated dots or points, which, on the longitudinal ribs, gradually produce an elongation or elevated line, dying out just above the next lower point, thus giving a kind of interruptedly striate or echinulate appearance to the surface. This beautiful little fragment is peculiarly well marked, and need not be confounded with any other. The surface bears some resemblance to Retepora echinulata ( Blainville, Man. D'Actinologie, p. 433 ; Michelin, Icon, zoophytolngique, pag. 72, pl. 14, fig. 11). Fig. 3 a. Natural size of specimen. Fig. 3 b. Portion enlarged, showing the rough surface of the coral, and the form of the fenestrules. Position and locality. Near the lower part of the Chazy limestone, associated with crinoidal columns, etc., at Chazy, Clinton county. 21. 1. STICTOPORA* FENESTRATA ( n. sp.). Pl. IV. Figs. 4 a, b, c, d, e. A stony expanded branching coral ; branches flattened, obtuse at the extremities ; surface on both sides covered by a celluliferous crust ; cellules in perpendicular rows, separated by elevated ridges and crossbars, oval or roundish, more elongated as they become worn, alternating and apparently increasing in semicircular transverse rows ; internal crust marked by concentric lines in the direction of the lines of cellules, as seen in fig. 4 e. This species is perhaps identical with one found in the Birdseye limestone, but differs in essential characters from the Trenton limestone species. Specimens more or less worn present diflerent aspects, and may be mistaken for different species ; and I have been in- clined to regard tlie specimens 4 a b and A c d as distinct, but further comparison and examination induces me to consider them identical. Fig. 4 a. Natural size of the branches of this coral. Fig. 4 i A portion magnified. Fig. 4 c. A fragment of another specimen from a different locality. Fig. 4 d. Portion of the same magnified. Fig. 4 e. A part of the axis of a specimen, denuded of the outer crust, and presenting a series of concentric lines, corresponding with the lines of progressive growth. Position and locality. This fossil occurs towards the lower part of the Chazy limestone, associated with crinoidal joints, Leptana, and other fossils of the rock ; the preceding corala arc also met with in the same as'-ociation. It is found at Chazy, Clinton county, and also near Galway, Saratoga county. (,Staie Collection.) • For generic description, see description of species under Trenton limestone. ,. CHAZY LIMESTONE. 17 22. 2. STICTOPORA GLOMERATA (n. 5yj.). Pl. IV. Fig. .5. The specimen consists of a surface several inches square, covered and crowded with this coral, denuded completely of its colluliferoiis crust. Its appearance is very similar to the specimen fig. 4 e, though its mode of growtli is considerahly dilferent ; and principally from this circumstance, as well as from the impossibility of defining the external characters of the coral, I have referred it, with some hesitation, to a distinct species. Position and locality. Granville ( Vermont), in a limestone, associated with Maclurea magna, which I have elsewhere shown to be identical with that of Cliazy. Genus STREPTOPLASMA ( Fam. Cyathophyllidea ) . [ Greek, iTTpe-irTos, twisted, and irXarfiAa, lamells.] Turbinate, gradually or abruptly expanding above; form like Cyathophyllum ; terminal cup more or less deep ; lamelhe vertical or longitudinal, more or less spirally twisted together when meeting in the centre. There is some objection to the application of the term Stromhodes of Sciiweigger to fossils of this character, or those formerly grouped with CyAXHopHVLLiF., as the genus was constituted for a diflferent coral. To indicate the prominent character, I have proposed this name as applicable to a considerable number of palaeozoic species. 23. 1. STREPTOPLASMA EXPANSA («. .fp.). Pl. IV. Figs. G a, b. Turbinate, short, expanding above ; terminal cup deep ; lamelhe fine, numerous. This species presents some variety of form and aspect, l)ut its essential characters are a short broad turbinate form, with a deep cell. It is imbedded in the crystalline encrinital limestone, and being itself usually in a crystalline state, it appears like the pelvis of a crinoidean. From this crystalline condition, nothing satisfactory can usually be learned respecting its structure. Position and locality. This species is apparently confined to the lower part of the Chazy limestone, not having been noticed above the position of the Maclurea magna. It abounds at Chazy, to the west and southwest of the village. (State Collection.) [Paleontology.] 3 Ig PALiEONTOLOGY OE NEW-YORK. 24. 1. CHiETETES { Species undetermined) . Pl. IV. Figs. 7 a, b, c, d. Small rolled masses, in the shape of acorns or eggs, arc common among the crinoida! plates in the Encrinal limestone at Chazy. Figs. 7 a, b, c. The specimens considerably magnified. Fig. 7 d. The ends of the tubes magnified. 25. 1. ACTINOCRINUS TENUIRADIATUS (n. .fyj.). Pl. IV. Figs. 8 & 9. Plates depressed -conical, somewhat irregularly hexagonal in form; margins deeply crenated ; surface marked by elevated sharp ridges, which meet at the sutures ; rays or ridges in about six fascicles, which are from three to five times divided before reaching the margin ; indentations of the rays producing the crenulations ; lower surface of the plates flat, presenting a deeply notched margin. The plates of this species, which appears to be new, are ver}^ aliundant in the Crinoidal limestone of Chazy : they have evidently been macerated for a long lime in water before being imbedded. Associated with these plates are a great number of fragments of encrinal columns ; and from the thickness and extent of the mass, which shows a large number of the plates, it is evident that, at one period, this was a favorite habitation of the crinoidea. The disturbance attending their destruction has so comminuted their remains, that no perfect specimens can be obtained. In form of plates, and mode of sculpture, this species somewhat resembles Cyathocrinus geometricus of Goldfuss, as figured by Phillips {Palceozoic Fossils, p. 135, pl. 60, fig. 41) . {State Collection.) 26, 2. ACTINOCRINUS? { Species undetermined) . Pl. IV. Fig. 10. A single plate only (perhaps belonging to this genus) has been found. Form octagonal, somewhat irregular, smooth or granulated (from weathering"?) . Position and locality. This specimen was found at the base of tlie limestone, and im- mediately at its junction with the Calciferous sandstone, about one mile west of Chazy village. 27. 1. ASTERIAS? {Species undetermined) . Pl. IV. Figs. 11 a,b. This specimen presents precisely the form and appearance of the madreporiform tubercle on the back of an listerias, scarcely differing from that of the recent species of our coast. It is entirely separated from any other organic body in the stone, though associated with large numbers of crinoidal fragments. Fig. 1 1 a. Natural size. Fig. 1 1 b. Magnified view. Position and locality. In the lower part of the limestone at Chazy. CHAZY LIMESTONE. 19 SHELLS, TRILOBITES, <$-c. OF THE CHAZY LIMESTONE. Plate IV. (bis). 28. 1. LEPT^NA PLICIFERA («. i7).), Pl. IV. (bis). Figs. 1 a, b. Senii-cUiptical, much wider than long ; convex valve slightly depressed along the centre, from beak to base ; surface marked by about 34 or 36 equal, somewhat coarse stria>, which radiate, apparently in pairs, from the apex of the shell, intermediate ones often appearing towards the margin ; stri;E sharp, with rounded grooves between ; visceral cavity, as shown by the cast, duplicate, separated by a sharp ridge, which extends towards the base of the shell. Width 1^ to § of an inch ; length j\ to \ of an inch. The condition of nearly all the shells of this species, which I have seen, is such as to render clear and definite descriptions almost impossible. It is mostly preserved in impres- sions of the outer shell, or as casts. It is quite unlike any species in the Trenton limestone, but approaches in some degree a small one in the Hudson-river shales. Fig. 1 a. Figure of the convex valve. Fig. I b. Cast of convex valve, witli a portion of the shell remaining : cast of visceral cavities magnified. Position and locality. This occurs in great numbers in some thin layers of limestone near the higher part of the mass, at Chazy, Clinton county. 29. 2. LEPT^NA INCRASSATA ( n. xp.). Pl. IV. (bis). Figs. 2 a, b, c. Shell thickened, almost semicircular ; dorsal valve very convex near the beak, gradually becoming flattened on the disc, and suddenly bending upwards near the margin ; ventral valve moderately concave, exhibiting a tliiekening near the margin ; surface marked by sharp elevated radiating lines, between which are broader spaces. The surface of this species presents a kind of thickening which partially obliterates the striae ; the ventral valve particularly exhibits this sort of incrassation. It occurs with the last described in considerable ntimbers, but differs in being larger, thicker and more convex, as well as in the form of the visceral markings. This species often bears some resemblance to L. interstrialis of the Trenton limestone, but is a much smaller shell, and differs from the young of that species in essential points. Fig. 2 a, b. Convex valves of this species. Fig. 2 c. Ventral valve. Fig. 2 d. Cast of the interior of the convex valve, and the same enlarged. Position a)id locality. In the thiiil)ed(led limestone, upper part of the mass, Chazy, Clinton county. ^stale Collection.) " 3" 20 PALEONTOLOGY OF NEW-YOEK. 30. 3. LEPT^NA FASCIATA (m. s/).)- Pl. IV. (bis). Figs. 3 a, b, c. Semi-elliptical, wider than long ; surface marked by prominent sharp stritp, between which are fascicles of three or four smaller ones ; striec dichotomous, and increasing to- wards the margin. This shell presents many of the essential features of L. interstrialis upon the external surface, but I am inclined to believe that a complete exposure of all the parts would prove it a distinct species. It differs from the young of that shell, in its more convex form and broader proportions ; while the fascicles of striee are remarkably distinct, but not crcnulated, as in good specimens of L. interstrialis. Fig-. 3 a, b. Convex valves of two individuals. Fig. 3 c. A larger specimen of the same. Position and locality. In the tiiinbedded portions of the Chazy limestone, upper part of the mass, near Chazy village, Clinton county. The specimen, fig. 3 c, is a larger in- dividual, apparently identical with this species, from Galway, Saratoga county, in the concretionary or brecciated portion of the rock. (State Collection.) 31. 1. ORTHIS COSTALIS (n. i;p.). Pl. IV. (bis). Figs. 4 a, b. Dorsal valve very convex, subconical, sloping rapidly towards the margin ; ventral valve flat; surface marked by about 32 distinct strong rounded radii, which are continuous, and enlarging towards the margin ; dorsal area large, triangular ; beak short, not incurved ; cardinal line nearly equal to the width of the shell. The strong rounded undivided costaeupon the surface of each valve distinguish this from any other species in the lower strata, though there is a larger species in the Trenton lime- stone which has sometimes undivided radii. The visceral impression imder the beak of the dorsal valve is narrow, somewhat tripartite at the base, and margined by a sharp ridge. Cast of the dorsal valve convex, strongly marked near the margin by impressions of the radii. This shell resembles in gcner;il form 0. testudinaria of the Trenton limestone, but is more convex above, the striae coarser and less numerous, and the beak is shorter and not incurved. The casts are likewise equally distinct. Fig. 4 a. An imperfect shell, showing- the radii towards the margin. Fig. 4 Z). A cast showing the visceral marking, and casts of radii near the hase of the shell. Fig. 4 c. An impnssion of the convex valve, smaller than the other specimens. Such impressions are abundant. Position and locality. In the (hinlicdtlcd upper jxirtion of the Chazy limestone, associated with all the other brachiopods of the mass. Chazy village, Clinton county. (State Collection.) CHAZY LIMESTONE. 21 32. 1. ATllYPA DUBI A («. .?;).). I'l. IV. (bis). Fig. f). Obovate ; beak of the dorsal valve extended, rounded and incurved ; front scarcely depressed ; surface marked by 30 or more radii. The specimen described lias nearly all the shell removed, and presents only the characters of a cast. The impressions of the radii are distinctly marked in tlie cast. I have observed but two or three individuals of this species. Position and locality. In the higher semi-oolitic layers of the Chazy limestone, Chazy, Clinton county. i State Colieciion.) 33. 2. ATRYPA ACUTIROSTRA ( n. sp.). Pl. IV. (bis.. Fig. 0. Obovate, minute ; base rounded ; beak acute, acuminate ; surface marked with prominent equal radii ; dorsal valve convex, elevated along the middle ; ventral valve convex, with a depressed line along the centre ; surface marlccd by about 12 or 14 equal rounded di- verging radii, the central one on the dorsal valve often extending only half way to the beak. This fossil is usually very minute, and, on that account, frequently overlooked ; but when once observed, its characters are sufficiently decisive. The beak is incurved, ending in a sharp point, which is often broken in detaching the specimen from the rock ; the radii are strongly marked, and the obovate form is usually well preserved. Fig. 6. The two lower figures arc of the natural size ; the upper one is enlarged. Positioji and locality. In the higher layers of the Chazy limestone, in considerable num- bers ; also in the oolitic portions of the mass, Chazy village, and near Galway, Saratoga county. (^state Collection.) 34. 3. ATRYPA PLENA ( «. sp.) . Pi.. IV. (bis). Figs. 7 a, b, c, d, e. Compare Terebraliila tripartila ul" the Silurian System, pl. 21, fig. 15. Somewhat quadrangularly gibbous or rotund ; front margin elevated in a moderately deep sinus ; beak of the dorsal valve small, closely incurved over the beak of the ventral valve ; surface marked by 16 to 20 strong radii, about four or five of which arc depressed, forming the sinus of the dorsal valve, and an equal number elevated above the others on the ventral valve. 22 PALEONTOLOGY OF NEW-YORK. The forms 7 a, b, c, d, e, are varieties of the same species. Tlie ventral valve of 1 d is remarkably elevated, and the wliole figure rotund. In 7 a, b Sc c, the form is more qua- drangular, with a strongly marked sinus and elevated ribs upon the ventral valve. This species is exceedingly abundant at Chazy, forming almost of itself thin layers of the limestone in which scarcely anollicr fossil appears ; it is frequently crushed, and presents a great variety of accidental forms. I have received specimens of the same fossil from Mr. Logan, Provincial Geologist of Canada, marked (on the authority of Mr. Phillips) Terebratula tripartita ; but our shell differs essentially in its proportions from liiat fossil, the length and breadth varying little, and the radii never bifurcating, though the mesial elevation is broad, dividing the surface " into three nearly equal parts." Fig 7 a. View of the ventral valve, showing the bcalc of the dorsal valve closely incurved over the beak of the former. Fig. 7 b. Lateral view of the same individual. Fig. 7 c. Dorsal valve of a small specimen. Fig. 7 d. Front view of a large specimen. Fig. 7 e. Dorsal valve of the same. Position and locality. In the thin layers of impure limestone near the upper part of the mass, and sometimes in the more compact portions. Chazy, Clinton county ; Galway, Saratoga county ; and near Montreal. estate Colkction.) 35. 4. ATRYPA PLICIFERA (71. 5J9.). Pl. IV. (bis). Fif;s. 8 a, h, e, d. Both valves depressed-convex, somewhat tetrahedral, varying to broadly oval ; beak small, acute, elevated and slightly incurved over the beak of the ventral valve, which is closely appressed to the lower valve ; surface marked by al^out 18 or 20 equal rounded radii, aliout 5 or 6 of which, on the dorsal valve, are slightly depressed, forming a shallow sinus, and the same number very slightly elevated upon the ventral valve. The .specimens 8 a, and 8 c, difler slightly in form, and the shell of one is more de- squamated than the other, but they are specifically identical. The number of radii in this and the last described species are the same, but in this they are more rounded, the shell altogether more depressed, and the sinus very shallow, scarcely extending more than half the length of the shell. This species occurs with the last ; and when they are crushed and distorted, as most of them are, it is not easy to separate individuals of the two species. Figs. 8 a, b. View of ventral valve, and front of same individual. Figs. 8 c, d. Ventral valve and front view of another individual. Position and locality. In (hinbcdded .shnly and siliceous limestone, near the uppi^r part of the Chazy limestone. Cliazy, Clinton county. {fHau- Collection.) CHAZY LIMESTONE. 23 36. 5. ATRYPA ALTILIS (tj. s;)."). Pl. IV. (bis). Figs 0 a, b, c, d. Rotund ; valves almost equally convex, rapidly attenuating from the middle to the beaks ; beak of the dorsal valve small, acute, incurved over the other, which is closely appressed to the dorsal valve ; surface of each valve marked by about 24 o(|ual rounded radii ; eight of the radii are slightly depressed upon the back of the dorsal valve, and much elevated in front, meeting an equal number of slightly elevated radii of the ventral valve. This species occurs with the preceding, but is more rarely seen ; it is clearly distinct, and readily identified by the more numerous radii, evenly rounded outline, and less angular mesial elevation and depression upon the two valves. This species resembles, in many points, the rotund forms of the higher strata. Fig. 9 a. View of the ventral valve, showing the beak of the dorsal valve. Fig. 9 b. View of the dorsal valve. Fig. 9 c. Lateral view of the same shell. Fig. 9 d. Front view, sliowing the elevation of the mesial radii. Position and localifij. In the upper part of the Chazy limestone. Chazy, Clinton county. 37. 1. ORBICULA'? DEFORMATA (71. .9^.). Pl. IV. (bis). Fig. 10. Suborbicular, depressed ; surface smooth ; apex scarcely elevated. Position and locality. In the higher layers of the Chazy limestone. Chazy, Cinton county. 38. 1. METOPTOMA? DUBIA (n. */>.). Pl. IV. (bis). Fig. 11. Oval ; ape\ elevated, incurved ; surface nearly smooth, or with fine concentric lines. Position and locality. In the lower part of the Chazy limestone. Chazy, Clinton county. 39. 1. ILL/ENUS ARCTURUS ( n. «/;.) . Pl. IV. (bis). Fig. 12. Buckler rounded and narrow in front, tliick, expanding abruptly towards its junction with the first articulations of the abdomen ; subtrilobate, the posterior angles much extended. A single articulation of the bodj' only is visible ; posterior edge of the buckler nearly straight ; eyes not visible, though their position is visible. The lateral lobes of the buckler are wanting, or greatly compressed and contracted. This individual is the only specimen found, and further discoveries may make it necessary to change the description to some extent. Position and locality. In fine semi-oolitic limestone at the base of the formation at Chazy village. {State Collection. 24 PALEONTOLOGY OF NEW-YORK. 40. 2. ILLiENUS CRASSICAUDA? Pl. IV. (bis). Fig. 1.3. Entomostracitcs crassicanda. Wahlenberg in Nov. Act. Peg. Soc. Upsal. 1S21. Vol. viii. pag. 27. tab. ii. ; pag. 294. tab. vii. fig. 5, 6. Illamus crassicauda. D.m-man, K. Vet. Acad. Handl. 1826. Pag. 65. tab. v. fig. 2 a - e. — — HisiNGER, Pet. Suecica, 18.37. Tab. iii. fig. .5. Fragment of buckler. Large, sub-hemispherical, gibbous, very thick and strong ; front margin involute. The portion remaining is essentially the central lobe of the buckler, the lateral portions having separated at the sutures. The specimen is more gibljous than common ; but on comparison with the figures above quoted, and with a perfect specimen from Russia, there appears to be no reason to doubt the specific identity. Position and locality. In subcrystalline oolitic limestone at Chazy in Clinton county, and in Galway, Saratoga county. 41. 1. ASAPHUS? OBTUSUS (?i. SJ9.). Pl. IV. (bis). Fig. 14. Caudal extremity semicircular, twice as wide as long ; surface finely granulated or smooth ; marginal expansion even, and not depressed as in Isotelus ; central lobe faintly visible by a gentle depression on each side ; no marks of articulations. This fossil varies from Isotelus, in the extremity being destitute of the apparent articula- tions which are seen in species of that genus ; and also in the marginal expansion being plain, and not depressed near the margin, as well as in being punctulated, and exhibiting none of those fine linings seen in the margin of Isotelus, Ill^enus and Bumastis. This fossil bears some resemblance to llie caudal extremity of Jisaphus palpebrosus, but the central lobe is less distinct than in that species. The middle lobe is less distinct, and the whole shell more evenly convex and smooth than any specimens of the Isotelus of the Trenton limestone. Position and locality. This species occurs in the compact limestone near the base of the formation, and where the rock is but little changed from the character of the Calciferous sandstone. It has been found only at Chazy village, Clinton county. (Stale Collection.) 42. 2. ASAPHUS MARGIN ALIS («.*yj.). Pl. IV. (bis). Fig. 10. Caudal extremity semi -elliptical, distinctly three-lobed, marked by 7 or 8 distinct pseudo-articulations, whicli are duplicate on the lateral lobes ; articulations not reacliing the margin, but terminating in a cruslaceous marginal expansion, which is depressed or chaiUR'lk'd near tlic edge as in Isotelus ; surface granulaled. t;HAZY LIMESTONE. 25 This is a very distinctly marked fragment of an undcscribed trilobite ; the distinctness of the false articulations, and deeply trilobate cbarrirter of the caudal extremity, distinguish it from known species of Isotelus, which it resembles in the marginal expansion and general form. Position and locality. This fossil is found in tlie crystalline and highly fossiliferous mass of tlie Chazy limestone, below the portion containing Maclurea magna, at Chazy village. (Slate Collection.) 43. 1. ISOTELUS GIGAS1 Pl. IV. (bis). Fig. IQ. Asaphns platycepfiahi.1. Stokes, Trans. Geol. Soc. London, 1S22, Second series, Vol. i. p. 208, pl. 27. Isutelus gigas. Dekay, Annals N. York Lycevim, 1&24. Vol. i. p. 171, plates 12 & 13. This fragment approaches so nearly in character to the caudal shields of the young of Isotelus gigas, that I have not thought it worth while to separate it from that species. 44. 2. ISOTELUS CANALIS. Pl. IV. (bis). Figs. 17, IS, 19. Isotelus canalis. Conr.^d in MS. Margin of caudal extremity broadly and deeply depressed, forming a channel ; surface ^punctured. Judging from this fragment, the original was at least six inches in length. Figs. 18 &. 19. Labrum or epistoma of an Isotelus, perhaps of /. canalis. The structure and general aspect of these portions of the trilobite evidently ally it generically with the Isotelus ; and from the discovery of these, I am disposed to admit the species which the fragment before mentioned did not justify. The form of these plates is more elongated, and totally different from the corresponding parts of /. gigas. Position and locality. These fragments of a large species of Isotelus occur near the upper part of the mass, a little west of Chazy village. (State Collection.) 45. 1. CERAURUS? — [ Species undetermined) . Pl. IV. (bis). Fig. 20. A single fragment, being the posterior prolongation of the buckler of a species of Ceraurus, very analogous to C. pleurexanthemus of the Trenton limestone. Position and locality. In the oolitic limestone of Chazy, (State Collection.) Remains of other trilobites, too indistinct to be described, have been noticed in this rock ; but the materials are so comminuted, that it is impossible to recognize fossils, of which fragments of many species have been observed. L Paleontology.] 4 26 PALiEONTOLOGY OF NEW-YORK. UNIVALVES (GASTEROPODA) OF THE CHAZY LIMESTONE. Plates V., V. (bis), & VI. 46. 3. MACLUREA MAGNA. Pl. V. Figs. 1 a, b, c, d; and Pl. V. (bis). Figs. 1 a, b, c. Maclurites magna. Leseuer, Jour. Acad. Nat. Sci. Philad., Vol. i. pag. 312, pi. 13, figs. 1, 2, 3. Mac/urea. Emmons, Geol. Report, pag. 270, fig. 1. Sinistrorsal, discoidal, depressed-turbinate ; breadth more than twice as great as the height ; spire flat, a slightly depressed line at the sutures ; whorls about six, gradually increasing from the apex, ventricose, flattened above, obtusely angular on the outer edge ; surface marked by fine striae, which, upon close examination, are found to be produced by the imbricating edges of lamellaj ; striaj undulating, bending backwards from the suture, and forwards in passing over the edge of the shell ; aperture obtusely trigonal, depressed above, slightly expanded beyond the dimensions of the whorl just behind it ; axis hollow ; umbilicus broad and deep, extending to the top of the spire. Plate V. Fig. 1. The upper surface partially denuded of the shell, showing the striae with the smooth cast beneath. I'his is a perfect representation of the shell, except that the minute terminal volution is not shown. Fig. 1 a. Side view of a cast of the shell, showing the depressed turbinate form and flat spire. Fig. 1 b. View of the lower surface, somewhat worn, showing the large umbilicus, which is partially filled with stony matter. Fig. 1 c. A vertical section of the shell, near, but not directly through the centre of the spire, showing several volutions and the deep umbilicus. Such sections of the shell are not unusual in the rock, and they are generally vertical to the lines of deposition. Fig. 1 d. A view of the shell worn down from the lower side, as it very commonly appears upon the weathered surfaces of the rock at Chazy. Plate V. (bis). Fig. 1 a. An obliquely vertical section of the fossil, passing nearly through the centre of the spire above, but more on one side below, so as to escape the umbilicus. Fig. I b. A vertical section of the outer volution. A common appearance upon the weathered surface of the rock at Chazy. Fig. 1 c. An unusually large specimen of the same species ; the surface worn so as to obliterate the striae, and obscure the first volutions. This shell is exceedingly abundant in the limestone at Chazy and some other places. Sections of the shell in every possible position are seen, covering the weathered surfaces and forming a large part of several strata, and less abundant in some others. In the black CUAZY LIMESTONE. 27 marble of He la Motte .itKl oilier localities it is quite abuiulaiit, and the polished slabs often present beautiful sections of this shell. This marble, being used for hearthstones, doorsteps, doorsills, etc., is extensively distributed l)y commerce, and meets one at great distances from its locality, always recognizable l)y this fossil. Indeed, some of the doorsills of tlic Aslor House in New- York, and of many of our pulilic buildings, present good examples of the fossil.* Its geographical range is known to be \ery great, extending from Northeastern New-York to Virginia, and even into Kentucky and Tennessee, and north- westerly nearly to Lake Superior. Localities. Chazy, Clinton county ; Watertown, JefTcrson county ; He la Motte ; Win- chester, Virginia ; St. Joseph's Island, in St. Mary's River. (5■ 69. 4. MURCHISONIA PER ANGUL ATA ( 71. s;;.). Pl. X. Fig. 1. Fusiform ; spire long, acute ; volutions rapidly diminishing in size, angular on the middle, appresscd above and below, except the last one, which is somewhat ventricose. There are some obscure traces of striae, and of the spiral liand, which enables us to refer the shell to the Genus Murchisonia, but it has been so much macerated as nearly to obliterate these markings. The shell is readily recognized by the strongly angulated whorls, which, above the lower one, are not ventricose. Position and locality. It occurs in a siliceous chcrty mass of the Birdseye limestone, associated with fragments of shells, corals, etc., near the upper termination of the rock. Watertown, JefTerson county. (State Collection.) [ Pal.eontology.] 6 42 PALEONTOLOGY OF NEW-YORK. 70. 5. MURCHIS0NIA1 VARICOSA («.*;>.). Pi. X. Figs. 7 a, b. Turreted, or ovoidly conical ; volutions rapidly diminishing, angular, ventricose ; surface marked with longitudinal ribs or strong striae, which are crossed by transverse ridges, giving it a varicose appearance. The specimens which I have seen are obscure from the adhesion of stony matter, but the species seems well characterized and easily recognized, and it is therefore given in its imperfect condition. The lower volutions bear about two or three prominent ridges or angular elevations upon the upper side, while they are more regularly rounded below. Fig. 7 a. A specimen having the surface much worn and weathered ; the markings are but partially visible. Fig. 7 b. Longitudinal section of a specimen of the same shell. PosUion and locality. This species occurs in the upper part of the Birdseye limestone, associated with Phytopsis and the preceding species of shells. It also occurs in the Black- river limestone, near its upper termination. Watertown, Jefferson county. 71. 1. NATICA? {Species undetermined) . Pl. X. Fig. 5. Volutions about four, rapidly enlarging from the apex, last one very ventricose ; surface smooth 1 ; suture apparently channelled ; spire but little elevated. This small shell is of rare occurrence in this rock, and I am by no means satisfied that it is distinct from a species of the Trenton limestone. It will be readily recognized from the figure. Position and locality. In the upper part of the Birdseye limestone, associated with Pleurotomaria, Phytopsis, and other fossils. Watertown, Jefferson county. 72. 5. PLEUROTOMARIA 1 NUCLEOL AT A («.«;).). Pu X. Fig. 6. Trochiform ; spire short, rapidly tapering to an obtuse termination ; volutions few, angular, flat above, the last one ventricose below ; suture canaliculate. The last volution composes nearly the entire shell, the upper ones being very small, and somewhat depressed. This is a small distinct species, which I have observed in no other position. Fig. 6 a. Natural size of specimen. Fig. 6 b. Enlarged view of the same. Position and locality. In tlie upper part of the Birdseye limestone, with the last species. Watertown, Jefferson county. BIRDSEYE LIMESTONE. 43 73. 6. PLEUROTOM ARIA QUADRICARIN ATA (n.sp.). Pl. X. Fig. 8. Trocliiform ; spire obliterated ; last whorl witli four distinct carina; ; surface marked with zigzag siria-, whicli advance and retreat in passing over the angles of the wliorl ; aperture nearly circular ; umbilicus large. It is impossible to characterize the whole of the shell, since all the specimens yet seen are more or less imperfect. The angles upon liic last volution, with the zigzag stria;, seem sufficiently characteristic of the shell to denote its specific distinction. Position and locality. In the higlier shaly part of the Birdseye limestone, associated with Phytopsis and the shells which follow. 74. 7. PLEUROTOMARIA UMBILICATA (71. «;>.). Pl. X. Figs, fi a, b, c, d, e, g, h. Depressed, nearly discoidal ; spire gradually ascending ; width about equal to twice the height; spire short; volutions about four, angular and compressed above, ventricose below; suture canaliculated ; aperture subrhomboidal, angulated anteriorly ; umbilicus large and deep ; surface marked with undulating striae. The last whorl is distinctly marked by three spiral ridges or carinations : one near the suture, one at the upper outer edge, and one at the lower outer edge, leaving the side of the volution plain and vertical ; the upper side is angulated by the first carina, and the lower side rounded, scarcely ventricose ; the lower angle of the last volution is covered by the spire, the two upper ones continuing. This fossil is readily distinguisiied, even in fragments, by the distinctly canaliculated suture, elevated upper carina, and the curvilinear depression between this and the next angle. This species is very common, appearing in the Birdseye limestone, and continuing into the Trenton limestone, where it is numerous and widely distributed. It assumes various forms, which are partly due to compression, Init retains its essential characters here given. Fig. 9 a. Lateral view of a cast of this species, the spire partially obliterated. Fig. 9 b. View of a larger specimen, showing but a single angle upon the cast, the upper one having been obliterated. Fig. 9 c. View of the upper side of a smaller specimen. Fig. 9 d. Lateral view of a specimen much compressed. Fig. 9 e. Lower surface of the same, showing the umbilicus and the strisB upon the shell, which is partially preserved. ■ ' Fig. 9 g. View of the upper side of a crushed specimen. Fig. 9 A. Lower side of a small specimen. When imbedded in the rock, and often inucli distorted, the dilTercnt phases of this fossil 6» 44 PALEONTOLOGY OF NEW-YORK. might be regarded as indicating distinct species, but a careful examination will decide them to be identical. For further illustrations of this species, see Trenton limestone, Plate XXXVI. Position and locality. In the higher shaly and irregularly stratified portions of the Bird- seye limestone, at Watertown, Jefferson county. {State Collection.) 75. 8. PLEUROTOMARIA? NODULOSA (n. i'j^.). Pl. X. Fig. 10. Turbinate, spiral ; spire ascending, short, obtuse ; volutions few, angular, ventricose, rapidly increasing towards the aperture ; umbilicus large ; surface marked by nodulose spiral ridges, which are crossed by longitudinal lines, giving the shell a varicose appearance. Tlie surface of this shell, the characters of which are partially obliterated, somewhat resembles Murchisonia varicosa ; but the spire is much shorter, and the last whorl larger and more ventricose. The large deep umbilicus is also a distinguishing feature of this fossil. Position and locality. In the upper part of the Birdseye limestone, associated with Orthoceras multicameratum and Phytopsis. (State Collection.) 76. 9. PLEUROTOMARIA? OBSOLETA (n. SJ9.). Pl. X. Fig. 11. Suborbicular, depressed-spiral ; volutions rounded, ventricose ; aperture round, with a posterior depression which apparently communicates with the umbilicus ; umbilicus small ; surface marked by longitudinal fine striae radiating from the umbilicus. Little more than a single volution of this specimen can be seen, the upper part of the shell being enclosed in the rock. The margin of the aperture does not present the notch characteristic of the Pleurotomaeia, and it is therefore referred with some doubt to that genus. Position and locality. In the upper part of the Birdseye limestone, associated with the preceding fossils. Watertown, Jefferson county. (State Collection.) 77. 1. CYTHERINA {Species undetermined). Pl. X. Fig. 12. Broken- and separated valves of this little crustacean are of common occurrence in the higher portions of the Birdseye limestone, though usually too imperfect for description. It is probably identical with a species in the Trenton limestone, which will be described in the proper place. Locality. Watertown, Jefferson county. (State Collection.) ^- ■>'•' ' n. '7 • ♦ y. *. ^j « ^■*i ■f- _ >. •* BIRDSEYE LIMESTONE. 45 ORTHOCERATA OF THE BIRDSEYE LIMESTONE. ■ Plate XI. . 78. 8. ORTHOCERAS MULTICAMERATUM. Pl. XI. Figs. 1 a, b, c. • ■ Orthoceras multicameratum, Conrad in MS. Emmons, Geol. Report, 1842, p. 382. Extremely elongated, slender, very gradually tapering to an acute point ; surface apparently smooth, or girt with slight undulations ; septa thin, gently arched, distant from \ to yV the diameter ; siphvmcle a cylindrical ventral tube ; outer chamber very deep. The difference in the apparent concavity of the septa is owing to the wearing of the fossil to different depths from the surface. The septa are very variable in their distance from each other, being from i to ^'^ the diameter, and presenting even greater variations than tliis, so that a single measurement would be no guide to the specific character. There will be found in this species, and probal>ly in others, a proportion between the distance of the septa and the diameter of the shell : where the diameter is greatest, the septa are pro- portionally nearer ; and where smallest, comparatively more distant. This proportion, however, is not always uniform ; for when similar diameters in different specimens are measured, one presents a greater number of septa than the other. This species resembles the 0. tenuiseptum of the Chazy limestone, but I have not sufficient evidence of their identity to unite the two. It occurs in great perfection in the Birdseye limestone, and is almost the only well marked species found in this rock. Fragments of several other species have been found, but none sufficiently characterized to merit description. Fig. 1. A fragment twelve inches long, showing a large part of the deep outer chamber, which is par- tially filled with fragments of the Phvtopsis (See Plate IX). Fig. 1 a. Another fragment, showing the continuation of the fossil to the apex. These two were not found in connexion, but are apparently fragments of two individuals. Fig. \ b. A fragment, showing some irregularity in the septa. Ficr. 1 c. A worn specimen, showing the septa and siphuncle which is near the margin ( ventral ? ). The siphon, in one part, shows something like an enlargement between the septa as in Ormoceras ; but it is too indistinct to warrant the reference. Position and locality. This fossil occurs principally in the higher and moreshaly portions of the Birdseye limestone, often surrounded and enveloped in fragments of the Phytopsis. Watertown, Jefferson county ; Mohawk valley. {State Collection ; Collection of the Albany Institute, i(e.) 46 PALEONTOLOGY OF NEW-YORK. 79. 9. ORTHOCERAS RECTICAMERATUM. Pl. XI. Fig. 1 d. Elongated, cylindrical, gradually tapering ; septa not curved, but passing obliquely in a line from the inside of the shell to the siphuncle, or vice versa ; siphuncle a cylindrical tube, somewhat excentric ; septa distant \ to j\ the diameter. This species bears considerable analogy to the last in some respects ; but it differs in the direction of the septa, which are not curved ; in tapering more rapidly, and in the siphuncle being less excentric. The specimens obtained give only partial opportunities of seeing the exact position of the siphuncle, which differs essentially from the last. . Position and locality. It occurs in the same association as the last, and all the specimens contain great numbers of fragments of Phytopsis. Watertown, Jefferson county ; Mohawk valley. BLACK-RIVER LIMESTONE. Succeeding the Birdseye limestone, we have a well-defined mass of greyish blue lime- stone, very compact and sometimes subcrystalline in texture. This has already been fully described, and is known as the Black-river limestone. It probably rarely or never exceeds ten feet in thickness ; but from being characterized by a large number of peculiar fossils, though mainly belonging to a single family, it is regarded as worthy of a separate notice. The principal and most prominent organic bodies in this rock are Orthocehata, some of which attain the astonishing length of more than ten feet, and have a diameter of one foot or more. Associated with these are several species of Cephalopoda belonging to other genera, and some species of the Gasteropoda which subsequently appear in the succeeding limestone. The Orthocerata and other Cephalopoda of this rock, so far as I have been able to ascertain, differ from any in the Trenton limestone ; and it would tlierefore appear that nearly every species perished at the close of this period. Several species, one of Pleuro- tomaria, and a few others, are identical with those of the Trenton limestone, and it is by these only that it is linked with the succeeding rock. Its organic affinities, however, are very close ; for in both this limestone and the. Trenton, great numbers of Orthocerata occur, though of different species. BLACK-RIVER LHVIESTONE. 47 CORALS OF THE BIRDSEYE AND BLACK-RIVER LIMESTONES. Plate XII. 80. 1. COLUMNARIA ALVEOLATA. Pl. XII. Figs. I a, b, c. Columnaria alveolata. Goldfuss, Pctrcfacta, pag. 72, tab. xxiv. fig. 7 a, b, c. — — Eaton, Geol. Text-Book, pag. 131, pi. 1. Columnaria. Emmons, Geol. Report, pag. 27G, fig. 2. A hemispherical or irregularly massive coral, consisting of radiating, parallel or diverging tubes ; tubes hexagonal (or varying from 5- to 7-sided ), striated longitudinally, crossed by transverse dissepiments with vertical radiating lamella: ; no communicating pores. The vertical lamellte converge from the sides of the cell towards the centre, but I have not yet seen a specimen in which they meet at the centre. These lamellae are unequal in number, varying apparently from twenty to thirty, and never meeting in the centre in our specimens : they are often partially obliterated, and leave the inside of the tube marked only by sharp ridges, corresponding to the striae upon the outside ; when the transverse dissepiments are also obliterated, these ridges are denticulated, marking the point of junction. The vertical lamella; are only visible in weathered specimens, as fig. 1 h, where tlie ends of the tubes are exposed. In a large number of specimens, the radiating lamella; are entirely obliterated, and the dissepiments only preserved, as in fig. 1 a. These are common at Watertown, Jefferson county. In the Mohawk valley and elsewhere, when preserve^d in compact limestone, the tubes are solid, separable from each other, end preserving very perfectly their deeply striated surfaces, as in fig. 1. The coral occurs in hemispherical masses, varying in diameter from three inches to several feet.* Fig. 1. A vertical section of a compact specimen, showing the striated walls of the cells. Fig. 1 a. A vertical section, showing the transverse dissepiments, with the vertical lamellae obhterated. Fig. \ b, A. transverse section (weathered surface), showing the radiating lamellze. Fig. 1 c. The same enlarged. Position and locality. Glensfalls ; Chazy ; Watertown ; Lowville, Lewis county ; Am- sterdam and numerous other places in the Mohawk valley, always confined to the Black- river limestone, and is never known to rise above it in any locality. In many situations, it forms a large portion of a single thick stratum near the termination of the rock. * There is a specimen (a portion only of an entire mass) in the State Collection, weighing about 1500 pounds : the whole mass probably weighed 2000 or 3000 pounds. This specimen is from the Mohawk valley, and was blasted from the rock in quarrying stone for the enlarged Erie Canal ; and I am indebted to the Engineer, Mr. M'Alpi.v, for being able to place it in the Collection. Certainly, when we find at so early a period such masses of coral, there is no reason why extensive coral reefs may not hare margined our early shoals or islands of granite, as those of modern origin do the islands and shoals of our present seas. 48 PALEONTOLOGY OF NEW-YORK. Genus S T R 0 M A T 0 C E R IU M. In the black marble of He la Motte, and in the same rock at Chazy, but more particularly in the dark limestone containing the Columnaria, we find numerous specimens of obscure corals having a structure represented in figs. 2, 2 a and b. They are completely silicified, so that the more minute structiu-e cannot be decided ; but since they are abundant, and require notice, I have proposed the provisional name of Stromatocerium, from rfrpwua, -aros, a layer or lamina, and xipiov, honeycomb. 81. 1. STROMATOCERIUM RUGOSUM. Pl. XII. Fig3. 2, 2 a, b. Coral hemispherical; growth in concentric laminas or strata ; laminae numerous, wrinkled; some faint indications of vertical tubes or cells. This coral usually appears as a rough shapeless excrescence upon the weathered surface of the limestone ; but a little examination shows it to be composed of concentric layers, which are evidently the skeleton of some coral. Fig. 2. A specimen, natural size, showing the concentric lamination of the coial. The masses are often several times as large as this one. Fig. 2 ffl. A fragment magnified, showing less contortion of the laminae, with some indistinct indication of vertical tubes or cells. Fig. 2 J. A small portion of a specimen of the natural size, showing the rugose or contorted direction of the laminae. Position and locality. This coral, so fiir as known, is confined to the Black-river limestone, and to the dark layers alternating with the Birdseye limestone. It occurs in the dark marble quarried on the east side of He la Motte ; but this mass lies much above the Maclurea magna, if not higher than the Birdseye limestone. It occurs at Chazy village, Watertown, and other places. 82. 2. CH^TETES LYCOPERDONI Pl. XII. Figs. 3, -5. .See Plates xxiii. and xxiv. Trenton limestone corals. A cylindrical branched coral ; branches somewhat clavate ; tubes fine, angular ; no connecting pores visible. There is no apparent difference between this species and the one so common in the Trenton limestone. It is extremely rare in the Birdseye, though I have been led to suspect its existence in many instances where the structure is wholly obliterated by crystallization, as is the case with many other fossils of this rock. The same fossil, apparently, occurs in worn ovoid fragments in the Chazy limestone, and its upward limit I have not yet as- certained. It lias, however, evidently a wide geological range ; coming into existence at almost the earliest period of organic life, and is among those rare forms that escaped de- struction, or again came into existence after the final deposition of the Hudson-river group. •• BLACK-KIVER LIMESTONE. 49 Fig-. 3. Specimen natural size. Fig. 4. Probably the same species, very minute^, occurring in some thin shaly layers at the upper part of the Birdseye limestone, or at its junction with the Black-rivcr limestone. Position and locality. Upper part of the Birdseye, and in the Black-river limestone, at Watertown, Jefferson county. 83. 2. STREPTOPLASMA PROFUNDA (n. 47).). Pl. XII. Figs. I a, b, c, d. Obliquely turbinate, often slightly curved near the base, expanding above more or less abruptly ; cell profoundly deep, extending nearly to the base of the coral ; margin of the cup reflexed ; surface scarcely marked by transverse rugae ; lamellae from 36 to 60, strong, nearly equal on the margin, but distinctly alternating in length within ; no transverse dissepiments or celhiliferous strncture. Specimens of this fossil occur in considerable numbers in the upper part of the Birdseye limestone, and in the Black-river limestone. One specimen in the State Collection presents the remains of more than sixty individuals upon a surface six inches square. This fossil never presents any evidences of budding from its centres, as in many of the CYATHOPHYLL.a: ; for among all yet seen, the individuals are single and distinct. When worn down longitudinally or obliquely upon the surface of strata, as in figs. 4 d, e, and similar forms, they have been regarded as the jaws and teeth of fishes, and this has given rise to the report of remains of fishes in these lower strata. The interior of tlie cup presents a serrated appearance, which is owing to oblique sections that are shown in the figures just referred to. Fig. 4. Lateral view of a specimen where the edge of the cup is worn down, shortening the entire length about one-third. Fig. 4 a. Section of a specimen near the base, showing the contortion of the lamellae at the centre : the section is slightly oblique. Fig. 4 b. Transverse section above the base, showing the alternation of larger and smaller lamells, which do not reach the centre. Fig. 4 c. Transveise section near the termination of the cup. I have some doubt whether the section here presented is of the same species, the lamellje being much stronger and less in number than in the other individuals, which all occur in one specimen of the stone. Fig. i d. A longitudinal section, slightly oblique to the axis, and coming out on one side of the centre below, showing some of the lamellas vertically and others obliquely — giving the serrated appearance before alluded to. Fig. 4 e. An oblique section, being nearly transverse to the lower part of the fossil on one side. Various other appearances are given by these natural sections on the weathered surfaces of the limestone, which are exceedingly instructive as illustrating the generic and specific characters of the coral. Position and locality. Watertown, in the "7-foot tier;" Chazy ; He la Motte ; also in great numbers at Manheim, East-Canada creek, in the Birdseye limestone. [ PALiEONTOLOGY.] 7 50 PALEONTOLOGY OF NEW-YOKK. 84. 3. STICTOPORA LABYRINTHICA («. «p.)- Pl. XII. Figs. 8 a, b. Coral composed of broad, flattened, flexuous, branching stems, diverging and ascending from a base ; branches uniting laterally, and forming broad foliaceous expansions ; trans- verse sections of a group presenting an irregularly reticulate structure ; branches celluliferous on both sides of the flattened central axis ; cellules oval, arranged in quincunx order. This coral occurs in tlie most compact portions of the Birdseye limestone, the edges of the branches appearing in dark lines upon the exposed surfaces of the stone, as fig. 8 a. In some localities large surfaces of the rock are covered in this manner, and it is nearly im- possible to trace their commencement or termination. In a few instances, the flat surfaces of the branches are exposed sufficiently to show the generic relations of the coral. The branches are broader than in tlie next described species, but the arrangement of cells is similar.* The edges of the branches liave much the appearance of Graptolites, except that they are rarely straight. Fig. 8. The weathered surface of a fragment of the limestone, showing the transverse sections of this coral of the natural size. Figs. 8 a, b. Enlarged portions as seen upon the specimen above, showing sections of two rows of cells rising obUquely from the axis. Position and locality. This fossil, as shown in iig. 8 and the magnified portions, is found only in the Birdseye limestone. It is abundant at Chazy village, Clinton coimty, and at Watertown, Jefferson county. (State Collection.) * Tlie accompanying illustration on wood may enable the student to comprehend more clearly the characters of this somewhat obscure fossil. The drawing is an exact representation of a small portion of the surface of the limestone, where this coral abounds. In many instances the branches are iiartially turned on one side, and present two or three rows of cells; but where fully exposed, the number of vows is above twelve. Fig. 1. A small fragment tif limestone, showing the natural size of the coral upon the weathered surface. Fig. 2. Vertical section of the same fragment of limestone, showing the ascending and anastomosing branches Fig. 3. F,nlargcd portion of the worn edge of a branch of the coral from fig. 1. Fig. 4. Surface apparently unworn, presenting elevated obliijue ridges between the rows of cells. Fig. .5. .Surface of a branch somewhat worn. BLACK-RIVER tIMESTONE. 51 85. 4. STICTOPORA RAMOSA (n. sp.)- " Pl. XII. Figs. 0, 7 &. 7 a. A brandling, erect, somewhat stony coral, covered on both sides by a cellulifcrous crust ; branches flattened ; cells oval, in quincunx order, arranged in regular oblique lines, alternating with each other in the direction of the axis, opening obliquely upward and outward ; mouths of the cells in perfect specimens elevated, more perfectly rounded at the upper side ; intercellular spaces striated? This fossil occurs in various conditions, generally more or less worn, and broken into fragments : when perfect, the mouths of the cells are clearly elevated ; when a little worn, they are even with the crust ; when more worn, the whole frond has a retepore-like aspect, and the intercellular spaces are proportionally much less. Fig. 6. A small fragment of limestone, the surface covered with pieces of the coral. Fig. 7. A small portion showing the base of the cells when separated from the internal axis. Fig. 7 a. The same magnified. Position and locality. Great numbers of fragments of this species occur in some thin shaly layers at the termination of the Birdseye limestone ; during the deposition of which, the species seems to have flourished in mirch greater numbers than at any other period.* (State Collection.) CRINOIDAL COLUMNS. ' - Pl. XII. Fig. 9. Fragments of columns of this kind, difTering in no respect from the species of the Trenton limestone, are found in the Black-river limestone at Watertown ( See plate and description of the same ) . * The accompanying illustration may render the character of this fossil more clear. ( I* ±a Fig. 1 is a fragment of stone, showing the fossil of its natural size. Fig. 1 a. A magnified portion, showing the ranges of cells and their regular alternation. Fig. 2. A small fragment of the coral, showing the bases of some of the cells. Fig. 2 *. The same enlarged, a, the external celluliferous crust, b, the axis denuded of tlie crust, showing marks of the cells, c, bases of the cells, the margin well defined, distinctly oval ; the longest diameter in the direction of the axis. 7* 52 PALEONTOLOGY OF NEW-YORK. CEPHALOPODA OF THE BLACK-RIVER LIMESTONE. Plates XIII. to XX. The Cephalopoda of this period present a remariiable development in numbers of in- dividuals though not a large number of species. The forms are all peculiar to the rock,* none of them iiaving been found in the higher limestone, though other species of the same family are so largely developed during the Tienton limestone period. Some of the Or- thocerata attain the enormous length of eight or ten feet, and arc not less than one foot in diameter. This period, though so well defined by its fossils, must have been one of short duration, during which the bottom of the ocean seems to have swarmed with myriads of these cephalopods. The deposition of calcareous matter which imbedded them, and, so far as known, destroyed the entire race, has not a thickness of above ten feet in New-York. Still the same deposit, containing the same species of fossils, is recognized on Lake Huron, and in Kentucky and Tennessee ; and even in Sweden, we have reason to believe that the same distinction may be made as here, and that in other parts of Europe the mass will be found marked by identical or representative species. 86. 1. LITUITES UNDATUS. Pl. XIII. Figs. 1, 1 a, 6, & 3 ; and Pl. XIII. (bis). Fig. 1. Inachtts vndatiis, Conrad in MS. Emmons, Geol. Report, pag. 394, fig. 1. Convolute, suborbicular ; spire equally depressed on either side ; volutions about four, contiguous, gradually increasing towards the aperture, which is subquadrate and scarcely expanded ; volutions rounded upon the sides and flattened upon the back, ventral side compressed from contact with the next volution ; surface undulated by strong oblique ridges and depressions, which rise from the inner side of the volutions, bend backwards, and become very strong upon the periphery ; entire surface covered with fine sub-imbricating strise, which are more distinct towards the aperture ; stria curving downwards, forming an arch upon the back of the shell. This rare and remarkable shell is readily distinguished by its flattened orbicular form, and strong retral ridges, which are very prominent on the outer edge of the volution, though usually scarcely indicated upon the plain flattened back of the last whorl, which is only marked by curved striai. * I have received a single species from Lewis county, as occurring in the Trenton limestone, which is identical with a species in this rock, and also the same from Herkimer county ; but I am not quite satisfied of the position in these instances. BLACK-RITER LIMESTONE. 53 Plate XIII. Fig. 1. Lateral view of a specimen. A part of the last volution, near the aperture, is broken off Fig. 1 a. Lateral view of the cast of a smaller specimen. Fig. 1 h. Dorsal view of the same specimen. Fig. 3. A section apparently of the same fossil, though the surface markings arc not preserved. The septa are distinctly shown in a portion of the shell, and lh(; dorsal siphon at two points a, a. I have not been able to ascertain positively the position of the siphon in the other specimens bearing the shell, figs. 1 and 1 a. Plate XIII. (bis). Fig. I. A large specimen, showing a part of the fossil denuded of the shell, the direction and distance of the septa, and a portion of the deep outer chamber, the extremity being broken off I am indebted to Dr. Crawb for the use of thi.s fine specimen, as well as for that on Plate XIII. fig. \. Position and locality. This fossil is known to me only as occurring at Watertown, Jef- ferson county, in the Black-river (or ^'■seven-foot tier" of) limestone, being unknown in any higher position. "" (State Collection.) 87. 2. LITUITES CONVOLVANS? Pl. XIII. Figs. 2, 2 a. Compare Lituites convolvans. Hisingeh, Pet. Suecica, 1837, pag. 27, pl. S, fig. 6; Anteckn V. tab. v. fig. 1, 2. Lihdtes imperfectim. Wahlenberg, Nov. Act. Reg. Soc. Sci. Upsal, 1821. Convolute, discoidal, gradually enlarging ; volutions about two or three, scarcely con- tiguous, outer one separating and continued in a direct line towards the aperture ; surface smooth?; section circular; septa plain, moderately concave, direction oblique from the inner side of the volution outward and upwards ; siphuncle dorsal? Two or three specimens of this species have been discovered, where exposed upon the weathered surface of the limestone, w'hich is too compact to allow of separating perfect specimens. So far as can be determined, the surface is smooth and the section circular. It is evidently closely allied to the L. convolvans ut supra, and probably identical with that fossil, which is found in the older limestone of Sweden. Fig. 2. A portion of a cast, showing the septa and part of the outer chamber. Fig. 2 a. A vertical section of another individual as seen on the weathered surface of the limestone, showing the septa, which are removed from the smaller extremity by weathering. The cast is worn down below the siphuncle, which has not been observed in any specimen yet seen. Position and locality. In the Black-river limestone, associated with large numbers of Orthocerata. Watertown, Jefferson county. 54 PALEONTOLOGY OF NEW-YORK. » Genus G0NI0CERAS( Fain. Orthocerata ). [Greek, yovios, an angle, and xspaf, a horn] Character. General form and structure of the Orthoceras ; the tube flattened, with extremely salient angles ; septa sinuous ; section an* xtended ellipse, with projecting angles ; siphuncle ventral. This genus is constructed to include a very peculiar form of the Orthocerata figured on Plate XIV., and which differs so essentially from all the other forms examined as to require separation. 88. 1. GONIOCERAS ANCEPS. Pl. XIV. Figs. 1, 1 a,b, c,d. ^ General form elongated, somewhat rapidly tapering from the base, extremely compressed; section an excentric ellipse, compressed laterally towards the extremities, and extended into very acute angles ; diameters as 1 to 4 or 1 to 5 ; septa composed of double laminae, deeply concave in the centre, numerous, thin, approximate, sinuous on the longest diameter ; siphuncle moniliform, ventral, consisting of a round tube, which is exceedingly expanded between the septa, like the siphuncle of Ormoceras. This remarkable fossil, usually appearing upon the weathered surfaces of rocks, with the ventral or dorsal side exposed, and presenting a broad surface with extended septa and central siphon, has received the appellation of '■^petrified fish's backbones.'" I had been disposed to regard this structure ( as represented in the plate ) as due, in part at least, to pressure ; but the examination of numerous specimens in the rock, and of a portion of one nearly perfect, compels me to decide that their apparent disproportions are natural, and not the result of accident. In a portion of a nearly perfect individual, the siphuncle is so near the outer shell as to produce a longitudinal ventral ridge. In this instance, the relative diameters confirm previous measurements. The shell is apparently smooth or very finely striated, and extremely thin, as also are the septa. There is very little evidence of compression, and the original form seems to have been very nearly what it now is. In tlie longest diameter of the ellipse, the septa bend rapidly forward from the siphuncle, till a little more than half way to the external shell, where they make a gentle curve more directly towards the exterior, and, before reaching it, curve a little backwards. In the opposite direction, the septa have but a simple curve. In this character, the septa bear some resemblance to those of Goniatites. BLACK-KIVER LIMESTONE. 55 Fig. 1. Natural long^itudinal section of a Gonioceras, showing a portion of the siphuncle, which is greatly expanded laterally between the septa, and contracted at their junction with it. In this specimen, the sides arc worn down below the angles of the shell, so that the septa do not . . appear to turn backwards or towards the apex, as shown in 1 a, where the section is more directly through the angles. Fig. 1 a. A longitudinal section, showing a small portion of the siphuncle at one extremity, and a more perfect exhibition of the curving septa towards the exterior of the fossil. Fig. 1 b. A transverse section, showing the position of the siphuncle. The specimen on the upper side of the figure has been slightly worn, so as to present a straight line. The siphuncle is nearer to the upper edge than is represented in the figure. Fig. 1 c. A transverse section near the smaller extremity of the shell, showing the position of the siphuncle. Fig. 1 d. A small portion of the exterior denuded of the shell, showing only the central portion of the septa. Position and locality. In the Black-river limestone, and limited entirely to that mass. Watertown, Jefferson county. {State Collection; Cabinets of the Albany Institute, of J. B. Crawe, and J. IIaix.) 89. 1. ORxMOCERAS TENUIFILUM. ■. ■ ■ Pl. XV. Figs. 1 a, b, c ; Pl. XVI. Figs. 1 a, b, c, d, e; and Pl. XVII. Figs. 1 a,b. Compare Orthoccratites crassiventris. Wahlenberg, 1S21, Petrefacta Telluris SuecanEe, in Nov. Act. Reg. Soc. Sci. Upsal, Vol. viii. p. 90. — — HisiNGEH, 1819, Anteckn V. Tab. iv. fig. 9. — — Id. 1837, Petref. Suec. Tab. x. fig. 3. Ormoceras Backii. Stokes, 1837, Geol. Trans. 2d series, vol. v. p. 709, referring to fig. 1, pi. 30 of vol. 1 .- 1 of the same work and same series. Conotubidaria Cuvierii. Troost, 1S3S, Memoires de la Societo Geologique de France, Tome iii. pag. SS, pl. 9, fig. 1 ; also fig. 7, pl. 10 of the same memoir. Actinocei xs. Bronn, as figured by Stokes, Geol. Trans, ut supra. Elongated, subcylindric, somewhat gradually tapering to a very elongated conical form ; siphuncle ventral, annulatcd or expanded into bladde.r-like rings at the junclion of the septa ; septa moderately concave ; surface marked by longitudinal undulated fine thread- like lines. The greatest expansion of the swelled portion of the siphuncle is just within the concavity of the septum, and the constricted portion is just above the convexity of the septum. The outer shell is thin, but it is connected with an interior one which often closely joins it by infiltration of mineral matter, when it presents a thickened appearance. The septa are likewise composed of double plates or lamina;, which separate and expand at the siphuncle, folding round and forming the outer shell of this annulated tube. In cases where these laminae separate a little nearer to the outer shell than in others, the rings, instead of being obtuse or rounded at their edges, are angular. This species of Ormoceras occurs in immense numbers in the Black-river limestone. 56 PALEONTOLOGY OF NEW-YOKK. The rock is very compact, and the fossil cannot be easily obtained except in weathered portions of the mass. Most of those figured, and nearly all the specimens usually seen, are found upon the weathered surfaces of the rock, where it presents such a variety of appearances as to lead one to believe there are several species. In examples like those on Plate XVI. they are conuiionly regarded by the inhabitants of the neighborhood as the vertebriE of fishes, to which they bear some remote resemblance. I have little doubt of the identity of this fossil with those cited above ; though since there is not absolute certainty, I have adopted another name until this can be determined. The specimens of Mr. Stokes are from a locality where the existence of other well known fossils induces us to refer the rock to the lower stages of our system, and probably to a position precisely corresponding to the thin mass containing these fossils upon the Black river. The specimens of Mr. Troost, though said by that gentleman to be associated with many from the younger silurian strata and some carboniferous fossils, I am well aware are from a position quite as low in the series as the Trenton limestone of New-York. It is true, Mr. HisiNGER has referred his Orthoceratites crassiventris to the more recent transition strata of Sweden, which would be a strong indication of its being a diflercnt species, if there be no error in regard to position.* Plate XV. Fig. 1. A fragment of this species, partially covered with the delicate thin outer shell, presenting in the lower part of the figure some obscure markings of the septa ; and above, showing the moderate convexity of a septum. Fig. 1 a. Transverse section of the same specimen, broken through the annulations of the siphon. Fig. 1 A. A portion of the outer shell magnified, showing the fine undulating threadlike lines upon the surface. (Specimen from the Cabinet of the Albany Institute.) Fig. 1 c. A longitudinal section of a portion of a large individual, showing the septa, which are com- posed of double plates reaching only to the inner lamina of the exterior shell. The distance between the laminsB is unusually great in the upper part of this specimen, the spaces between them being nearly as great as between the septa. Plate XVI. Fig. 1. A transverse section, showing the edge of an annulation of the siphon, and the proportionate size a{ this part of the fossil. (By a mistake of the artist, the upper edge of this ring is far too nearly central to be true.) Fig. 1 a. An artificial longitudinal section of a portion of fig. 1, pi. 15, showing the siphon and septa. Fig. 1 b. A longitudinal section, in a direction from ihe ventral to the dorsal side, showing very clearly the position of the siphunclc. Tiic specimen appears contracted at both extremities, which is due to its having been slightly bent, so that in wearing down, the two extremities arc worn beyond the centre, while the middle portion is central, showing the siphuncle almost in * The structure of siphuncle here represented, thoU!;h common in the lower, is rare in the higher strata; and although we have sumetliing approacliing to the same form, yet I liave not hitherto been able to detect precisely the same in any of the Orthocerata of more recent periods than the Hudson-river group. BLACK-KIVER LIMESTONE. 57 contact with the external shell. Fragments like this one are of frequent occurrence, inducing -^ a belief that it is a distinct species ; and the figure is given here for the purpose of explaining the manner in which such a section is produced, which may bo cither Ly a previous bending of th(? shell, or from wearing down unevenly upon the surface. Fig. 1 c. A longitudinal section, similar to the last, but the shfll not bent ; the direction of the section is nearly in the ventral and dorsal lines. Septa and outer shell showing double laminae. Fig. I d. A longitudinal section, showing the siphuncle apparently central, which is due to a wearing down from the ventral side, and consequently leaving the siphon equidistant from the two lateral margins of the shell. Fig. 1 e- A similar section to the last, both of which exhibit more or less distinctly the double laminae of the outer shell and septa. In figs. 1 b, c, e, the double lamina of the outer shell and septa are not so clearly dis- tinguishable, the interspaces in the fossil being filled up by calcareous matter, so that both shell and septa appear thickened. In 1 a and 1 d, particularly the latter, the double laminoe of the septa are quite distinctly preserved, the interspaces being empty. This structure will be more fully illustrated when treating of the generic character of the Orthocerata. Plate XVII. Fig 1. A fragment of the same species, showing the siphon directly in contact with the ventral side of the shell, a portion of which remains on the lower part of the specimen. There is also a slight irregularity in the size of the annulations, which is a common occurrence. Fig. 1 a. Transverse section of the last, showing the wrinkled inner surface of the siphon at the points of contraction.* Fig. I b. A longitudinal section, passing through the siphuncle : the interior is here filled with stony matter ; but in other specimens, the inner surface of the tube presents the same wrinkled appearance along the contracted portions as is represented above, fig. 1 a. In presenting so many figures of this species, the object 1ms been to prevent misapprehen- sion, and to present to the student in the science the most obvious features, and those apparent variations which he might seize upon to form distinct species. Doubtless they will be presented under other aspects ; but it is believed that a careful study and comparison of these figures may enable one to detect the important characteristics, and decide their identity with these forms. In the Transactions of the Geological Society of Lo?idon, Second series, Vol. i. pi. 30, are to be found some analogous forms ; and if there be no fallacy in these, which I somewhat suspect, there arc several species indicated. From the geographical position of these fossils, it may be inferred that their geological position is identical with those of New-York. Position and locality. In the Black-river limestone, associated with Gonioccras, Lituites, Columnaria, &.C. &c. Watertown and Henderson Bay, Jefferson county ; Copenhagen and Lowville, Lewis county ; rarely in the Mohawk Valley, Lake Huron, &c. (.•'Hate Collection.) * See figures of Actihocer.vs in Trans. Geol. Soc. London, 2d series. Vol. v. pi. 19. [Palaeontology.] 8 58 PALEONTOLOGY OF NEW-YORK. 90. 2. ORMOCERAS TENUIFILUM 1 var. DISTANS. Pl. XVII. Fig. 2. Form as previously described ; septa a little more distant ; form of siphuncle, as appears near the base, somewhat different, and resembling very nearly Ormoceras Bayfieldii (Stokes, Geol. Transactions, 2d series, Vol. i. pi. 9, fig. 1 ). A partial longitudinal section on the opposite side displays the same structure as figs. 1 c, d, e, on the previous plate, and I have regarded this as a variety of the last species. The specimen before us is worn down to the siphuncle only towards the lower part of the figure ; and the peculiar form there presented is probably owing to weathering, or some accident, as I have seen the same in another specimen since this was figured. Position and locality. With the preceding. 91. 3. ORxMOCERASI GRACILE (». ;?jj.). Pl. XVII. Fig. 3. Slender, elongated, very gradually tapering ; septa distant about ^ of the diameter ; siphuncle'? surface? This species is distinguished by its more slender form and distant septa. The siphuncle is not distinctly visible ; but from some other evidences, it is presumed to belong to the Genus Ormoceras. Position and locality. Watertown, in the Black-river limestone. {Cabinet of the Albany Institute.) Genus ENDOCERAS. [Greek, ivSov, within, and xipag, a horn.] I propose this term, at least provisionally, to include those species of the Orthocerata whicli liave a large siphuncle, mostly lateral or excentric, marked or ridged on the outer surface by the septa, which, from their oblique direction, give it the appearance of a tube with spiral lines. Within this siphuncle are one or more very elongated conical tubes, often one witliin another to the number of four or five. Tliis latter ciiaracter is one of the essential features of the Jlctinoceras of Bronn ; but the foimdation of this name implies an impossibility, and requires a structure incompatible with the economy of the Orthocerata ; and, therefore, for our specimens at least, we must substitute another.* • I shall be able to show, under the Orthocerata of the Trenton limestone, tliat such a structure as that of rays in verticillalions from the internal tube to the walls of the si])hon could never e.xist in an animal conslifulod like the Orlhociras. These tubes, being developed one within the other, and remaining witliin the siphuncle only temporarily, and capable of separation without injury to either the young lube or the parent shell, could never have been provided with verticillating rays to sustain themselves in that position. We have also such numbers of them separated from the parent shell, that had there been any such structure, some indications of it would have been preserved. BLACK-RIVER LIMESTONE. 59 92. 1. ENDOCERAS SUBCENTRALE (n. s/..). Pl. XVII. Fig. 4. External form unknown, mucli elongated ; septa rather distant ; siphuncle a large straight subcentral tube, with external iml)ricating elevations at the attachment of the septa. The septa, on approaching the side of the siphuncle, turn suddenly upwards, or towards the apex, before joining the tube. A small portion only of the internal tube is visible, but enough remains to show its character. The marking is too faint to be traced, but it probably differs from any other species in this rock. Position and locality. This fossil occurs, associated with the Ormocehas, in the limestone of Black river, at Watertown, Jefferson county. {State Collection.) 93. 2. ENDOCERAS LONGISSIMUM ( n. sp.) . Pl. XVIII. Figs. 1, 1 a. Extremely elongated, cylindrical. In the specimen before us, the internal embryo tubes of the siphuncle, only, are preserved : these are cylindrical, elongated, very gradually tapering, each one fitting within the other nearly close at the aperture, but receding from each other towards the smaller extremity ; markings of the surface not visible. The section 1 a shows at least three distinct tubes, one within the other, which extend the whole length of the specimen. The portion figured is eighteen inches in length, and this is probably much less than half the whole length of the original. Fragments of this species are very abundant at Watertown, and they are often found embraced within portions of the original shell, which was at least six inches in diameter and several feet in length. The two figures connected by a dotted line are parts of the same specimen, joining as indicated. The section 1 a shows the different tubes, one within the other. Position and locality. In the Black-river limestone, associated with Ormoceras. Water- town, Jefferson county. (Cabinet of the Albany Institute.) 94. 3. ENDOCERAS MULTITUBULATUM (n.5;j.). Pl. XVIII. Figs. 2 a, b. Teretely conical, tapering somewhat rapidly ; embryo sheaths numerous ( five ) , one within the other ; sheaths thin; smooth externally ; interspaces equal, narrow. This species differs from the last, in tapering more rapidly towards the apex, and in the consequently different form, as well as in the greater number of sheaths, which latter, however, would not be regarded as important. Position and locality. In the Black-river limestone at Watertown, Jefferson county, associated with those forms previously figured. 60 PAL^ONTOLOY OF NEW-YORK. 95. 4. ENDOCERAS GEMELLIPARUM ( n. sp.) . Pl. XIX. Figs. 1 a, b. Teretel}' conical, somewhat rapidly tapering ; siphuncle lateral ; septa moderately convex, distant ; surface 1 This fragment is of large size, being four and a half inches in diameter. It is remarkable for presenting, enclosed within the siphuncle, two embryo tubes, which in themselves show some lines of septa indicating their tendency to perfection. The apices of both these tubes, as in all cases of single embryo tubes, are directed towards the apex of the parent shell. One of them is slightly bent on one side, and covered with stony matter. Fig. 1 a. External view of the fragment. Fig. 1 b. Transverse section of the smaller extremity, showing the siphuncle tube which joinj the external margin ; witliin which are shown sections of the two embryo tubes. Fig. 1 c. Longitudinal section of the specimen, d and e being the two enclosed tubes, one of them partially covered with stony matter. Position and locality. In the Black-river limestone at Henderson's Bay, Jefferson county. 96. 10. ORTHOCERAS FUSIFORME ( n. sp.) . Pl. XX. Fig. 1. Elongated, gradually tapering ; outer chamber deep, gradually contracting towards the mouth, giving a fusiform aspect to the specimen ; septa approximate ; siphuncle excentric. This species presents the peculiar character of contracting towards the aperture, at about the same rate that it diminishes from the last septum in the opposite direction. The siphuncle is a large apparently even cylindrical tube. Two specimens only have been observed, both of which are from the base of the Black-river limestone, near its junction with the Birdseye. This species possesses a character which I have observed in some others, namely, that of having several of the last septa, and the final one especially, more closely arranged than the others. Locality. Watertown, Jefferson county ; Valley of the Mohawk, Herkimer county. TRENTON LIMESTONE. 61 TRENTON LIMESTONE. This limestone is more important than cither of the preceding, in geographical extent, thickness, and number of fossils. It. usually succeeds the Black-river limestone, or, in its absence, the Birdseye limestone, in thin shaly layers, or in compact strata separated by shaly larainw. In a few instances the rock is concretionary in its lower portions, a large proportion of shaly matter being intermingled. The rock is for the most part thinbedded, of a dark blue or black color. Towards the higher part of the mass we usually find some thickbedded grey subcrystalline strata, bearing quite a different aspect from the rock below. Tracing the rock upwards from this point, we find a gradual increase of shaly matter, until finally the whole mass becomes a shaly limestone, thence passing into the succeeding black shale by imperceptible gradations. The rock is highly fossiliferous throughout, some localities furnishing more than others, and offering better facilities for procuring them. The number of species figured show how prolific it has proved, even under a very imperfect investigation. Perhaps none of the higher groups furnish a greater number of species in the same extent of tliickness and surface exposed, than docs this rock. In describing the rocks of New-York in the Geological Reports, it was found convenient to separate the Trenton limestone from the Utica slate, and the succeeding shales and sandstones of the Hudson-river group. The same distinction has been kept up in the present Report, though a more thorough investigation of the pala;ozoic features of these different rocks has proved that many of the fossils are common to the Trenton limestone and the Hudson-river group, while a few species of the limestone appear in the Utica slate. Among the trilobites, we may mention the Calymene Blumenbachii, which abounds in the Trenton limestone, is rare in the Utica slate, and more frequent in the Hudson-river group. The Trinucleus is common in the Trenton, abundant in the Hudson-river group, though rarely seen in the Utica slate. The Triarthrus Beckii abounds in the Utica slate, and is rare both above and below, though occurring in both situations. Nearly all the species of the Brachiopoda of the Trenton limestone reappear in the Hudson-river group, though rarely seen in the intervening slate. There are, at the same time, species in the Hudson-river which are unknown in the Trenton limestone, and vice versa, though their palaeozoic relations are very intimate throughout. From all these facts, I am disposed to unite the whole as one group, still retaining the subdivisions for convenience of reference. This seems the more desirable, since at the west, particularly in Ohio and Indiana, the augmentation of calcareous matter has made it im- possible to draw any line of demarcation which shall correspond with the three divisions so obviously marked by their lithological characters in New- York. Q2 PALa:ONTOLOGy OF NEW-YORK. FOSSIL PLANTS OF THE TRENTON LIMESTONE Plates XXI. & XXII. In the soft shaly portions of this limestone, there are considerable numbers of the fucoid- like veo-etable, fig. 1, pi- 22. They often appear as if attached by roots, but are never branched. More rarely species like fig. 1, pi. 21, appear upon the shaly surfaces of the limestone. Great numbers of obscure vegetable markings, or fragments of fucoid-like bodies, are frequently found in the shaly strata of the Trenton limestone, in nearly all localities where the surfaces are exposed. These bodies are coextensive with the rock, and even much more numerous in some western localities, and in Canada, than within the State of New-York. 97. 2. BUTHOTREPHIS GRACILIS (n. «;).). Pl. XXI. Fig. 1. Stem slender, flattened, branched ; branches compressed, leaflike, subdichotomous, diverging, opposite and alternate ; no visible structure. This is a beautiful species, very similar to some of the linear-leaved Potamogetons. A carbonaceous film is all that remains of the fossil. It was probably a succulent marine plant, not unlike Fucus, but of a very slender form and habit. It occurs where the crystalline limestone is separated by thin shaly layers, upon which, and upon a shaly carbonaceous film on the limestone, this fossil is found. Position and locality. Jacksonburgh and Middleville, Herkimer county, in the central and lower portions of tlie Trenton limestone. C^'"'* Collection.) 98. 3. BUTHOTREPHIS SUCCULENS ( n. sp.) . Pl. XXII. Figs. 2 a, b. Fossil composed of thick succulent stems ; stems branching ; branches divergent, bi- furcating ; structure apparently cellulous, indistinct. This fossil resembles, in its thick succulent stems, the Salicornia. It is one of the most prominent and remarkable species in tlie rock. Tliis is the Lithodcndron dichotomuin of Eaton. Fig. 2 a. A portion of a large specimen, the branches scarcely compressed. Fig. 2 b. A single stem with branches, from another plant. Position and locality. In the Trenton limestone. Glen's Falls. (Cabinet of the Troy Lyceum.) TRENTON LIMESTONE. 63 99. 3. PAL.EOPIIYCUS RUGOSUS (n. .syj.). Pl. XXI. Fig. 2. Compare with P. tvbularia, PI. iii. figs. 1, 2, I, 5. Stem subcylindrical, rough, Ijianched ; branches cylindrical, diverging at nearly right angles from the main stem. The .surface of the stem is very rugose, or irregularly pitted and ridged ; the branches flexuous, and nearly rectangular to the stem. This species is commonly obtained in fragments, and presents a great variety of appearance. Position and locality. Middleville ; West-Canada Creek, and below Prospect Hill, in the Trenton limestone. ■-• (State Collection.) 100. 4. PAL^OPHYCUS SIMPLEX ( n. 5p.) . Pj.. XXII. Figs. 1 a, b, c, d. Stems simple, cylindrical (or flattened and angular from compression ) , flexuous, gra- dually tapering to an oljtuse point ; surface smooth, or with indistinct interrupted ridges or striae ; one side often with a longitudinal groove. The stems are apparently hollow tubes, as the interior is filled with fragments of shells, crinoidal columns, etc. The crust, or substance of the stems, appears to have been of moderate thickness ( one-half to one line ) , and flexuous or elastic, as they are frequently bent and compressed. These fossils usually occur in short fragments, but they are not unfrequently met with in larger portions of six inches in length, and of the diameter of half an inch or more. From their tubular structure, flexuous form, and apparent attachment by roots, they have evidently been organic bodies. This species is perhaps more numerous than any other in the limestone, as I have obtained several hundred fragments of various lengths and dimensions. It appears to have grown only during the shaly deposition, and is imbedded in this portion of the mass ; consequently it is absent or obscure where such material is wanting as a component part of the rock. Fig. 1 a. A portion of a large stem, and section. Fig. 1 b. A fragment compressed and bent. ' . ■ Fig. 1 c. Section of the same. Fig. 1 d. A small fragment, showing the groove along the side of the stem. Position and locality. In the lower shaly portions of the Trenton limestone, at Middleville, Herkimer county. («'"'« Collection.) 64 PALEONTOLOGY OF NEW-YORK. CORALS OF THE TRENTON LIMESTONE Plates XXIII. to XXVI. The corals of the Trenton limestone are limited to a moderate number of species, and a few only of these are abundant ; but one species, the Ch^tetes, in some of its varied forms, abounds in nearly all localities of the rock. These species, of which there about eighteen, are referable to no less than twelve distinct genera. The Chcetetcs Lycoperdon, in hemi- spheric forms, often abounds in certain layers, to the almost entire exclusion of any other fossil ; while the slender and branched varieties of the same species are foimd in other situations, covering the entire surface of strata for many yards in extent. These corals rarely attain to massive dimensions, though we sometimes meet with irregular forms weighing ten or twelve pounds. This species is far more abundant than any other, and, in some of its protean forms, is every where met with in the Trenton limestone, being much more numerous than all the other species together. During the entire deposition of this rock, the condition of the ocean does not appear to have been favorable to the continued growth of corals, since no massive species are found in it. This is probably owing to the constant intermingling of shaly matter during the time, which interfered with the growtli of these animals ; for there seems no other sufficient reason, since such large masses of the Columnaria are found in the thin layer of Black- river limestone below this rock. The western extension of this formation shows, during the same period, the existence of immense numbers of corals, none of which attain to large dimensions, though in their present condition they form a considerable proportion of some of the strata. 101. 2. CH.^TETES LYCOPERDON. Pl. XXIII. Fjg3. 1, 1 a, b, c, d, e,f, g, h, i, &. 2, 2 o, 3 ; and Pl. XXIV. Figs. 1 a, b, c, d, e,f, g, h, i, k, m, n, o. Favosites Lycoperdon. S.iY. Favnsites /i/copodites. Vanuxem, Geol. Report, pag. 48, fig. 3. Emmons, Geol. Report, pag. 3S9, fig. 3. Calamopuiu fibrosa [ ? ] Goldfuss, lS2tj, Pctrol^icta, pp. 82, 215, tab. xxviii. figs. 3 & -1 ; tab. xxiv. fig. 9. Fai'ositcs fibrosa? Goi.pfuss, ISS.'?, Petref. corrigenda, p. 215. Compare Chlic[ue sides which support two interbrachial plates, against which the edges of the cuneiform arm-joint rest. The structure is fully explained by the figure 1 b, where the dotted lines connect the sides of the plates as they are arranged in the fossil. The column is round, moderately large, and composed of joints which alternate in this manner : the last joint, adhering to the pelvis, is a thin plale with crenulaled edges, whicli is succeeded by a thicker joint with a rounded smooth edge ; again a thin one with a crenulated or fimbriated edge, and so on alternately. The entire surface of the fossil is rugose or sculptured in Imes and points, the edges of the plates joining by slight sutures. No perfect specimens have been seen, and we are ignorant of the entire length of the fingers and tentacula, which were probably as long as in the last species. Fig. 3 a. A specimen (natural size), with the fingers and colunin broken off; the form otherwise well preserved. Fig. 3 b. The structure and arrangement of the plates, the letters indicating the parts as explained in the previous figures. The plates are slightly enlarged beyond their natural size. 86 PALEONTOLOGY OF NEW-YORK. Fio-. 3 c. The base of the specimen magnified, to show the fimbriated plate adhering to the base of the pelvis. Fig. 3 d. Lateral view of a smaller specimen of the same species, with portions of the fingers remaining. Y'lf. 3 e. The same, showing the base, with a fragment of the column broken off and lying at the side. Fig. 3 / A portion of this column magnified, to show the character of the plates. Position and locality. In lire soft shaly layers interstralified with tlic calcareous beds in the lower part of the Trenton limestone, at Middleville, Herkimer county. 126. 2. SCHIZOCRINUS'? Pl. XXIX. Fig. 1. A fragment composed mainly of the fingers and tentacula of an encrinite, closely re- sembling, and probably identical with, that figured on Plate XXVII. The joints of the fingers are cuneate ; the tentacula attached to the thicker edge ; the latter plain, and not jointed. The fingers are much longer than those of the specimen just referred to, but the individual was also larger : the number is the same in both specimens. Position and locality. In the compact limestone, associated wiih numerous shells of this rock, at Sugar River, Lewis county. (State Collection.) BASES OF ATTACHMENT OF CRINOIDEA. Pi,. XXIX. Figs. 2 a, b. The base or rootlike attachment of the columns of some species of Crinoidea are some- times found in this rock, attached to other fossil bodies. The specimens figured are both attached to a worn specimen of the Chatetes lycoperdon. It is imcertain to what species they belong. Locality. Trenton Falls. (.State Collection.) COLUMNS OF CRINOIDEA. Pl. XXIX. Figs. 3 a, b, c. Pentagonal columns, and fragments of other columns of which the body has not been seen in the Trenton limestone, are sometimes found in the central and higher portions of that formation. For description and illustration of the one figured above, see Crinoidea of the Hudson-river group. Locality. Middleville, in grey crystalline Trenton limestone. The specimen fig. 3 c is a fragment of an unknown crinoidal column, which presents the peculiarity of being deeply striated longitudinally, and having distant enlarged plates, which project, with rounded edges, beyond the general circumference. It may perhaps belong to the Poteriocrinus or Scyphocrinus, small fragments only of the columns of these having been seen. Position and locality, Middleville, in the lower part of the Trenton limestone. TRENTON LIMESTONE. ', 87 Genus ECHINO-ENCRINITES. Echino-encrinite}, Herman Von Meyer, 1826. Karstner, Arcliiv. fur die Naturlelire, Vol. vii. p. 1S5 - 19-2, pi. 2, fig. 1 - 5 ; Vol. viii. p. 232 - 237. Echinosplueritcs, Pander, 1830, Sp. Bronn, 1835, Sp. Goniocrinittn, Eichwald, 18-10. Echino-encrinus, Volborth, 1842. > Sycocystites, Von Buch, ISM. This genus is one among the few which Von Ruch has incliuicil in his family Cystidea, a group intermediate between the Echinidea and the true Crinoidea, and whicii pass into the latter by the genus Caryocrinus, wiiich combines in some degree the characters of both groups. The discovery of a species of this genus among the fossils of our older strata furnishes another interesting link, connecting in their palaeozoic characters the rocks of the European continent with those of America, and showing that at so early a period, when the peculiar forms of Echinodkrmata, the Crinoidea, flourished in considerable numher.s, a genu.s also existed which indicated a structure intermediate between that then numerous family, and the future Echinidea, a portion of this great group being at the same geological period represented by a true Asterias. The following extract, translated from the observations upon this genus in the second volume of the Geology of Russia and the Ural Mountains, will convey a more definite idea than my own language ; since, thus far, I have had no opportunity of examining anj' other than very imperfect specimens. This easily characterized genus belongs, as well as the Echinospii>erites, to the Crinoidea with closed summits and destitute of arms, or the Cystidea of M. de Bucii ; but it is distiaguished from the first, by the small number of its plates, their form and their regular arrangement. We find in them, indeed, only four basal plates, ten intermediate plates forming two ranges of five each, and five superior plates which imite at the summit. Of the four basal plates, three are quadrangular, and the fourth becomes pentagonal by the truncation of its salient angle. This last is exactly opposite to the two poriferous rhombic plates, of which we shall speak immediately ; and upon its truncated side is placed one of the plates which extends to the great lateral circular aperture, and which helps to form its contour. This opening is free, without enclosing plates ; and as this is the only one, except the mouth, which we discover on the surface of these bodies, it is very probable that it served both as the anus and as an ovarian aperture. M. Volborth supposes that it was divided in the interior, to serve this double function. It is certain that we see on none of our specimens the convex and pentagonal star, which is always remarked on the Echinosphaerites. Another very important character of the Echino-encrinites, is their being provided with a thick, round, creuse, elastic and contractile stem, which, by its thickness, contrasts with the small, and still so little known stem, of the other genera of the group Cystidea. This stem is not articulated like those of the Encrinites, and appears to be composed of tubes resting one within the other, and graduated like the compartments of a spyglass : it is besides covered with longitudinal strias, and appears to u.s, as also to M. Volborth, very analogous to, if not identical with, the Comvlites serpularius of authors.' • See fig. 3, p. by. m I*, 88 PALEONTOLOGY OF NEW-YORK. The surface of the Echino-rncrinitcs is irregular, unequal, and embossed. The plates of the shell are convex, sub-pyramidal, and ornamented with thick and reticulated striae. These stricP, always perpen- dicular til the s'lles of the jitate, as in the Echinosphserites, form, by their combination in successive chevrons, five or six rhombs radiating from the centre of these. The union of these rhombs forms triangles inscribed one within the other where the plates are regular, or in part having a common base, whrn, by the reduction of the sides of a plate, one of the rhombs become rudimentary The smallest of these triangles, comprised between three faces of the pyramid, corresponds with the»angles of the plates of the shell The Echino-encrinites is further distinguished by the presence of pores, not disseminated over the entire surface as in the Echinosphajrites, but occupying a determinate place, and bordering three small rhomboidal areas. These p 'res were only imperfectly defined by Schlotheim in his Eckinnspharites granatvm and by M FIrrhan von Meyer in his Eckinn-encrinites senkenbergii ; it is to M, VoL- B'-RTH that we are indebted for having exactly marked their place ( See Bull, de Saint- Petershourg, Vol X., no. 19, pi. 1, fig. 4, 5, G ). Two of these poriferous rhombs are .situated near the base, and have their gre-it diagonals united upon one of the angles of the opening where the stem is inserted ; while the third is found on the opposite side, between the mouth and the great lateral opening, and directly above the pentagonal basal [late : the two first are mounted upon the plates of the two inferior ranges, and the last upon those of the two superior ranges. What was the design of these pores, or elongated grooves, which bound the three rhomboidal areas? It would, doubtless, be difficult to affirm any thing on this subject : il is sufli.'ient to remark that these pores are disposed according to the same law as in the Echinosphasrites, or the Hemicosmites ; that is to say, that they part from the centre of the plates, and unite at their angles. The middle of the rhomboidal areas are usually striated ; but the strife are less distinct than upon the rest of the crust, and appear some- times a little w-orn The crust is in general solid, and crystallized in rhombohedrons as in all the crinoidea. The genus Erhiiin-encriniles has been established by M. Herman Von Meyer, in the Archives of Kaustner, upon a specimen now unfortunately lost The description and the figure which he gives of it are nevertheless exact enough to enable us to recognize, without hesitation, the fossil bodies of Saint- Petersburgh, confounded by MM Pander and Bronn with the Echinosphaerites, and named by M. EicHWALD GonocrvLiles. M. de Buch, struck with the impropriety of the name of M. Herman von Meyer, has proposed, in his Memoire of this year, to change it for that of Si/cocijsli(e^. Although this name, it must be allowed, may be better than that which we have adopted, we prefer to follow the rule which we have imposed upon ourselves, to preserve always the most ancient names. The Echino-encrinites belong, as well as the Echinosphaerites, to the Lower Silurian system of Russia. M. Volborth, to whom we owe a notice upon those of the environs of Saint-Petersburgh, distinguishes three species of them in this country : the E. siriatiis, angulosus, and granatum. AVe possess only the two first of these, and we do not believe that the third species is identical with the Echiiiospkxritcs granatum ( Wahl.), to which this author compares it. Indeed, according to M. he BticH, this last species, of which he makes the type of his genus Caryocystites, should have a very different number of plates, and the striae not reticulated. The Echino-encrinites senkenbergii ( H. von Meyer) constitutes probably a fourth species. M. Bronn, in his Lethaa Geognoslica, had reunited it to \\\c Echinosplmriles granatum (Schlot.); but in the additions and corrections of the same work, p. 1284, he says that M. Herman von Meyer has shown that this reunion has no foundation. The Echino-encrinites appear exclusively to belong to Russia; at least we do not know of their occurrence elsewhere. If the Cornulites serpularius is only a part of their stem, there is reason to believe, nevertheless, that they will be found in Gothland and in England, where this singular body has been discovered. {Geology of Russia and the Ural Mountains, Vol. ii. pp. 27, 2S & 29.) t^ TRENTON LIMESTONE. 89 * 127. 1. ECHINO-ENCRINITES ANATIFORMIS ( n. sy>.) . Pl. XXIX. Figs. .1 rt, i, c, d, e,f. Body composed of four scries or ranges of plates ; basal or pelvic plates four, three of them pentagonal, and one wiiii the upper angle truncated ; second series hexagonal ; ihe tliird series indistinct, those forming the summit not visible. Column short ; lower ex- tremity very slender, and composed of joints which are twice or thrice as long as broad ; in ascending, the diameter increases, and the joints are shorter, finally becoming flat rings with prominent sharp edges, being nearly one half the diameter of the cup above. The summit of the specimen pri^seiUs an apijearanre as if the original had been provided with arms or tentacula, but there are no remain.s of tiiem ol)S(;rvaiile. Our species approaches very closely to those figured and described by H. VoN Meyer and VoLBORTH, as quoted by Von Buch in his paper on the Cystidea* ; and also those * Journal of the Geological Society of London, No. 5, 1846. The accompanying illustration, fif;. 1, is from this paper of M. von Buch, ami will convey a more definite idea of the form of these bodies than tlic imperfect specimens tlius far seen in our rocks. .K' Fig. 1 a, the summit, with the mouth ; b, the ovarian aperture ; c, tlie base. Fig. 2. Lateral view of a specimen, showing the ovarian aperture. Fig. 3 a, the base of the specimen ; 3 b, lateral view of tlie same. Fig. 4. A portion of tlie column of the same species. Fig. 5, as above, is the Echino-encrinites striatus of Panher. A small portion of the column is still adhering to the body, and the side on which is situated the ovarian aperture a is much extended. {Paleontology of Russia and the Ural Mountains, pag. 29 & 30, pl. 1 & 27.) M. VoLBORTH has recently discovered the very delicate tentacula of the Eehino-cncrinitcs (Bulhtin de la Classe Phys. Math, de S.-Petersbourg, Vol. iii. no. 0 ). They are placed on the border of the buccal aperture, and do not pierce tlie plates as in ordinary Crinoideans. These tentacula are not fimbriated ; and since, according to M. v. Buch, the animal was provided with an ovarian aperture, they were not required for protecting the eggs, as in the true crinoideans. The views of von Buch, however, do not entirely coincide with those of M. Volborth, who regards this aperture as the anus.* * S«e note on page xiv. t>f M. PR Verneuil's General View of the PalKozuic Fiiuna of Russia. [ Palaeontology.] 12 90 PALEONTOLOGY OF NEW-YORK. in the Paleontology of Russia and the Ural Mountains, as cited above, which are the only authorities within my reacli. The specimens examined are very imperfect, consisting first of a column and a few scattered plates, which were collected by myself in 1835 ; and subsequently, since the first pages of this report had passed through the press, of some more perfect specimens, collected by Dr. Budd, in Lewis county, who has kindly forwarded them for my examination. There are some slight differences observable between the European species and this one, the most obvious of which is the greater elongation and breadth of the cup near the top in the latter. This feature, however, may be due to compression ; as the condition of our specimens, which are imbedded in a shaly calcareous mass and usually crushed, docs not admit of minute comparison. The occurrence of this fossil, so nearly allied to, if not identical with, the Russian species, is an exceedingly interesting circumstance, since all the specimens before known are from a single locality (Pulcowa) in Russia. The position also corresponds precisely ; for, in that country, these peculiar fossils occur only in the lower part of the Silurian system. So true is it that certain organic forms are reliable in the determinalion of the age of certain formations,, that M. de Verneuil, on seeing my specimens, pronounced the rock, without hesitation, the Trenton limestone, which rock is unquestionably identical with the great Orthoceratite limestone of Russia and Sweden. The illustrations which I have been able to give, are the following : Fig. 4 a. The column, will) a single detached plate near its uppci termination. The long narrow joints of the column, which gradually become shorter and broader until they form broad thin rings in the upper part, are clearly shown. The plate belongs to the second range, and is hexagonal, with three prominent ridges upon its surface. A curved depression on one side shows that it formed a part of the lateral aperture. Fig. 4 h. Part of a .similar column, with the plates of a crushed cup lying at its upper termination. There are, at the summit of this specimen, one or two free nearly circular discs, and one apparently attached, as if forming the base of the tcntacula at one point. Fig. 4 c. One of these plates enlarged. The surface is worn smooth, with the exception of the ridges upon the plate, but this is doubtless due to maceration and abrasion. Fig. A d. K larger and more perfect specimen ; the plates near the base showing the strong striie upon their surface, which are at right angles to the edges. Fig. 4 e. The structure, as far as can be ascertained from our specimens. Fig. 4/. The surface of one of the plates, magnified, to show the striae. Position and locality. The specimens first obtained are from the midst of the fossiliferous portions of the Trenton limestone, associated with Chcetetes, OrtJiis festudinaria, ^'c. The last arc from a stratimi upon which a layer of shaly matter has been deposited, imbedding the fossils. The rock contains no other fossils. Turin, Lewis county. TKENTON LIMESTONE. 91 128. 2. ASTERIAS MATUTINA (n. .9/j.). Pu XXIX. Figs. 5 a, b. Body small, wiili five radiating aims; arms elongated (length twice and a half the width of the body), terete, acute, composed of three rows of plates, which join above by their lateral margins. Beneath each upper lateral row of plates there is an inferior lateral range visilile, leaving the sulcus beneath the middle row, which is often depressed. The dorsal plates are somewhat hexagonal ; those of the arms quadrangular : surface punctate or granulate, perhaps from tlie removal of the spines covering the surfiicc. The .specimen is considerably cruslied, and two of the arms broken off at the base ; the madreporiform tubercle upon the back is not visilile in our specimen. From its condition, the structure cannot be entirely made out, but it is sufficiently clear to enable any one to recognize the species. Three specimens of this highly interesting species are known to me, two of wliich occur in the Trenton limestone of New-York. It ])ears some resemblance to the one found at Cincinnati ; but it would appear, from the figure and description of Prof. Locke ( Pro- ceedings Acad. JVat. Sci., Vol. iii. p. 33 ), that it is a distinct species, being at least twice as large, with the centre proportionally larger, and the plates composing the arms smaller than in our species. The name {Jlsta-ias antiqua) given by Prof. Locke, i.s already appropriated by Troost for a very distinct species, judging from his figure (Trans. Geol. Soc. Pcnn., Vol. i. p. 232, pi. 10, fig. 9 ) , and probabl}- holding a higher geological position. Prof. Troost also mentions ( page 235 of the work just cited ) having " found five other species of free AsTERiTES : one of them occurring in a lower stratum than that in wliich the Jl. antiqua is imbedded, and the four others in a higher situation ; all, nevertheless, below the Coal." It is therefore quite certain that the Genus Asterias existed during the deposition of the older Silurian rocks in localities widely separated from each other, and also that the genus is represented I)y more than a single species. Fig. 5 a. The specimen, natural size. Fig. 5 A. A portion enlarged, showing the form of the plates and the punctate surface. Position and locality. The specimen figured is from the thin shelly layers at Trenton falls, about midway of the rock. Another specimen has been found near Canajoharic, probably from a lower position in the Trenton limestone. An imperfect specimen, ap- parently of the same species, has been found in the shales of the Hudson-river group, by Gen, Spinner, of Mohaw'k. (Collection of W. H. Pbase.) 12* 92 PALEONTOLOGY OF NEW-YORK. 129. 1. TENTACULITES? FLEXUOSA (m. s;j.)- Pl. XXIX. Figs. 0 a, b, c, d. Tubes single or aggregate, adhering, more or less curved at the tip or along the whole length ; surface marked by strong annulations, which are crossed byfine longitudinal striae; annulations somewhat irregular ; interior distinctly septate ; septa with the concave sides upwards. The mode of growth and the interidr structure here developed give us more information regarding the habits of this hitherto doubtful fossil, than we have before possessed. If the species in question be a true Tentaculites, of which perhaps we may have some doubt, it appears to have been developed like many of the Corals, viz. a simple tube affixed at the base, occupied by an animal which secretes calcareous matter, building up the walls of the cell, and extending across it transverse septa as the tube became elongated. The structure of the tube, however, allies it more nearly with Crinoideans than with Corals ; and it is probable that it was inhabited by a simply constructed animal of the same order. The specimen fig. 1 a first attracted my attention by its curved tip, showing that it must have been attached to some other body. A further careful search among a large number of specimens from Lowville enabled me to discover the attached group, which shows that an exudation of calcareous matter attaches them firmly to the shell, while a group of the cells of Chcetetes lycoperdon have commenced their growth on the same. I have referred this, with some hesitation, to the Genus Tentaculites, both on account of its general form and mode of adhering to other bodies, as well as from its internal structure, which, however, has not heretofore been shown in the true Tentaculites. All the other species known in our strata are straight, rigid, and gradually tapering to a point, always separate, and never known as adhering to other bodies. Fig. G a. A single specimen of this species, with a portion of the same magnified, showing the transverse septa. Fig. 6 J. A group of the same species, adhering by their smaller extremities to the dorsal valve of Orthis iesludinaria. At c, there is the base of several cells of the Chatelcs lycoperdon, adhering to the same shell. Fig. 6 d. A single tube, magnified, showing more distinctly the striae upon the surface, and, also, in some degree, the irregularity of the annulations. Position and locality. This fossil is only known to me as occurring in the thinbeddcd portions of the Trenton limestone, from sixty to one hundred feet above its base. Lowville, Lewis county. TRENTON LIMESTONE. 93 BRACniOPODA OF THE TRENTON LIMESTONE. Plates XXX., XXXI., XXXII. & XXXIII. The BRAcniopor).\ of lliis period arc among the most numerous and prominent fossils of the rock. Several species are so abundant as to constitute of themselves entire strata, and others cover extensive surfaces of the thin layers. Those whicli occur in the greatest profusion in New-York, arc the Orthis testudinaria ( identical witii the species of the same name in Europe), and Leptcena scricca ; while other forms of Lkptjena arc scarcely less abundant in some localities. In the western extension of the sanu- rock, the Delthyris lynx and Atrypa protea are equally abundant ; but these species are comparatively rare in New- York, and are nev'er prominent species in any localities east of Oiiio. The species of this order are comparatively constant and rclialile throughout extensive areas, and the t3-pical species of this rock in New-York are C(|ually characteristic of strata of the same age in Ohio and Indiana. It is true, tliat both in this State and in all ilic western localities, many of tliese species are equall}' cliaractcristic of the upper part of this great group, viz. the Hudson-river rocks. In New-York, some of the same species which mark the Trenton limestone are equally abundant in the shaly sandstones of the Hudson-river group ; while in the latter, we do not know of more than two species, at the present time, distinct from those in the limestone below, and tiicse may yet be found in a lower position. It is from the occurrence of these species of Brachiopoda in tiie Hiidsou-rivcr group, together with species of other genera, that I am induced to unite the whole, as before stated, in one great series, though the lithological characters are so dilfcrcnt in the two extremities. Among others, the Lingul.e hold a prominent place ; this limestone containing half as many as we know, at present, in all the other palaiozoic rocks of America. This is the more interesting, since tiiis genus, containing species of the same lype, exists in the waters of our present seas, together with the Orbicula, another prominent fossil of this period ; while the other genera are unknown as existing forms. Although the number of species of this order is nearly as great as of any other group of equal thickness, still it is probable, from what we already know, that the number will be increased at least one half, and perhaps doubled, when the Brachiopoda of the same period in the West shall be fully known. It is probable that we shall yet discover species in New- York which may swell the present number considerably, though we can scarcely anticipate that we shall ever discover all those species which flourished in the more favorable conditions of the western ocean of that period. 94 PALEONTOLOGY OF NEW-YORK. 130. 4. LINGULA ATTENUATA1 Pl. XXX. Figs. 1 a, *. Compare Lingula attenuala. Sowerby in Sil. Researches, pag. 641, pl. 22, fig. 13. Also LinguLa acuminata, page 9 of this Report. > General form ovate-acute, attenuated towards the apex ; sides nearly straight ; front rounded ; surface depressed, marked by concentric lines which are crossed by obscure radiating striae. This description corresponds essentially with that of Sowerby, except that our shell is never smooth. The concentric lines are more or less strongly visible in all our specimens. The' sides are straighter, and the shell more attenuated towards the apex, than in any other species which we have in this rock : it varies in form, however, to a considerable degree, as will be seen on comparing different sjiecimens of the same species. Fig. 1 a, is the largest individual of this species yet seen. Fig. 1 b. A specimen of the ordinary size. It should be observed by the student, that the proportional strength of the concentric and radiating lines on the Lingula are influenced by the exfoliation of the shell which takes place in many of them. In some cases the concentric lines are partially or entirely obliterated by this process. In figs. 1 fl and b, the radiating stria; are visible, from a partial exfoliation of the shell. Position and localily. This species occurs in greater nmnbers aliout midway from the base to the top of the Trenton limestone, and is often met with in other parts of the rock. At Middleville, which is the best locality for all the species of the genus, this one is found about fifty or sixty feet aboYe the Birdseye limestone. It is also found at Trenton Falls, Jacksonburgh, Lowville, Watertown, and other places. The usual associates of the Lingula are the Conularia, Leptana allernata, and sometimes the small corals, as Sticfopora, fyc. The species found in the Calciferous sandstone is far more attenuated than any which we find in the Trenton limestone, and is perhaps tpiite distinct from the L. attcnuata of the Llandeilo flags, as it is, apparently, from the present species. That figured by Murchison is intermediate in form between the two, being less attenuated than the one in the Calci- ferous sandstone, and more attenuated than the one imder consideration. If the LiNGUL.ff:, like other genera of the Braciiiopoda, were influenced in form by the nature of the sediment deposited, or the ocean bed on which they lived, then the same species may present the extremes of form here noticed. TRENTON LIMESTONE. 95 131. 5, LINGULA RICINIFORMIS. Pi.. XXX. Figs. 2 a, b, c. Oval, convex, sliglitly attenuated towards the beak, which is obtuse; surface nearly smooth, or with fine nearly obsolete concentric lines. Fine radiating stria; are sometimes visible ; and the .surface is sometimes slightly ridged, as if from elevated lines beneath the outer lamina of the shell. The general oval form and equal convexity of tlie shell are ahiiost its only distinguishing rliaracters. It is less attenuated towards the beak tliau the last, and the surface is not so distinctly striated. The length of this species does not exceed y\ of an inch, with a width of little more than y\. Compared with figs. 1 a, b, it is less attenuated towards the beak, and not depressed towards the front, which latter feature appears to be constant in the L. attenuata. That species also becomes more spatulate or expanded towards the base as it increases in size, which is shown in 1 b. The figures 2 a, b, c, are from three specimens, varying in size, but all presenting the same form. Position and locality. This species occurs with the last in compact dark limestone near Middleville, Herkimer county. (*''«'« Collection.) 132. 6. LINGULA JEQVAUS {avaridy of the last species?). Pl. XXX. Figs. 3 a, b. Broadly oval, very obtuse, somewhat attenuated near the beaks, regularly convex, rounded in front ; surface marked by fine radiating stria; and less conspicuous concentric lines. This shell differs from the last, in its greater proportional widtli, and almost equally obtuse extremities. Length and breadth about as 5 to G. In addition to the very fine radiating striae upon the surface of the shell, there are some undulating ridges or wrinkles which are not very distinct. The radiating stria; are often obsolete or inconspicuous, and, to the naked eye, the surface appears entirely smooth. The shell is usually less convex than the last species, which it closelj' resembles. Position and locality. In the compact limestone, near the centre of the mass, at Middle- ville, Trenton Falls, &c. t ■1" . 96 PALjEONTOLOGY of NEW-YORK. 133. 7. LINGULA QUADRATA. Pl. XXX. Fig3. 4 a, b, c. Crania quadrata. Eichwald, 1S29, Zool. specialis. Vol. i. pag. 273, pl. 4, fig. 2. I.ingula quaibata. Eichw. 1S40, .Sil. Syst. in Esthland, p. 104. _ — Id. 1S40, Urwelt Russlands, heft 1, p. 15. _ _ Id. 1S42, Ibid, heft 11, p. 58. — — MuRCHisoN and Verneuil, Geol. Russia and tlie Ural Mountains, Vol. ii. pag. 292, pl. 1, fig. 10. Eqiii valve, equilateral, broadly oval, depressed-convex ; sides nearly straight and parallel, or slightly curved; extremities nearly equal in Avidth, the first broadly rounded, cardinal extreniily slightly narrower and somewhat angularly sloped ; beak marginal, not prominent; exterior surface of the shell marked by strong concentric stria?, and along the middle by distinct longitudinal striir, which are equally visible when the outer shell is exfoliated. A longitudinal depressed line marks the shell from the beak nearly half way to the base. This species is perhaps the largest fossil Lingula known : it is distinguished by its general elliptical form and nearly parallel sides. In its dimensions it is near the Lingula Lewisii ( Sowerby ) ; Init it is more regularly rounded at the base, and does not present the square outline which tiiat shell has. Our largest specimen is one inch and a half in length, with a width of almost an inch. The usual length of this shell is one inch, and its great size alone is commonly sufficient to distinguish it from any other species in our strata. The longitudinal striae mark only the central part of the shell, and arc equally distinct when the shell is exfoliated : this character may be useful in detecting the species. Our shell is evidently identical with that of Russia, as cited above, both from the figure and description, and from the opinion of M. de Vekneuil, who has seen the Trenton sjiecies. Fi<^. 4 a. A specimen of the ordinary size; the shell partially exfoliated, and presenting the strong radiating striae along the centre. Fig. 4 //. View of the edge of the sliell, with the two valves closed. It appears slightly inequivalve from compression. Fig. 4 c. A specimen of larger dimensions, from wliich the shell is partially exfoliated. Position and locality. This species occurs in the central and higher part of the Trenton limestone, usually in the compact dark layers, unassociated with otiier fossils. In some instances, it occurs in the higher gray rock. Trenton Falls, Middleville, Turin, Lowville, and other localities in New-York. It has a wide geographical range, l)oing known in Ohio and Wisconsin, where its geological position is similar to that in New-York. Its occurrence in several localities in Russia proves its distribution over an immense area in the palaeozoic seas. TRENTON LIMESTONE. 97 134. 8. LINGULA ELONGATA ( n. sp.). Pl. XXX. Fig. 0. Oblong oval, gradually narrowing towards the beak ; sides nearly straight ; shell much elevated along the centre, which continues to the beak, and is slightly depressed in front ; a narrow depressed line extends along the length of the shell, from the beak, more than half way to the base ; surface marked by fine concentric striae, without visible longitudinal ones. Length of the shell, li ; width, /j of an incii. I have seen but a single specimen of this shell, but its great elongation, and entire freedom from radiating stria, either upon the outer surface or where exfoliated, seem to me sufficient marks of distinction. Our shell corresponds in many respects with Lingula jiarallela of Phillips {Geol. Yorkshire, Vol. ii., pl. 11, fig. 17-19), as described by PoKTLOcK ( Geol. Report, pag. 444, pl. 32, figs. 6, 8 & 9 ) , but his specimens are much smaller ; the original shell, moreover, occurs in a much higher position, which alone would be a fair presumption against it being identical with the one of the Trenton limestone. Position and locality. In the compact dark limestone in the central part of the rock. Lewis county. (C'a4m« 0/ Mr. Vanuxem.) 135. 9. LINGULA CURTA. Pl. XXX. Figs. Ga,b. Lingula curia. Contrad, Jour. Acad. Nat. Science, Vol. viii. pag. 266, pl. 15, fig. 12. Obtusely ovate, flat or depressed convex ; beak small, often scarcely prominent ; surface marked by concentric elevated lines or wrinkles ; apex obtuse ; base broadly rounded. The length and breadth of this shell are nearly equal, and the beak often scarcely projects beyond the outline of the shell. In the Utica slate, it is quite flat from compression, while in the limestone it is depressed convex. • " • Fig. 6 a, is from the Utica slate, the same specimen figured by Mr. Conrad. Fig. 6 b, is from the Trenton limestone. When the shell is exfoliated, tine radiating striaR are visible. Position and locality. Middleville and East-Canada creek, in the compact dark limestone, nearly in the central part of the rock. It occurs also in a higher position, and in the Utica slate ; also at Carlisle ( Pa.), in Utica slate. [ Paleontology.] 13 98 PALJ;ONTOLOGY OF NEW-YORK. 136. 10. LINGULA OBTUSA { n. sp.). Pl. XXX. Figs. 7 a, b, c. Broad-ovate, obtuse at the apex and regularly rounded below, depressed in front, but very prominently convex on the umbones ; beaks obtuse, prominent, not terminal ; margin of the shell a little produced beyond the beaks ; surface apparently smooth, but, under a magnifier, exhibiting fine concentric and radiating striae. This shell is easily distinguished by its ovate form, with very obtuse apex ; the beak is prominent and elevated, with a narrow space between it and tlie margin of the shell. The outline from beak to base is much more arched than in any other species. Fig. 7 ffl. A very perfect specimen of large size, giving the exact form of the shell : radiating striae scarcely visible. Fig. 7 b. Another specimen, the form not quite as perfect as in the last, but the radiating strise more distinctly visible. Fig. 7 #. A smaller individual of the same species. Position and locality. In the more shelly central part of the Trenton limestone at Middle- ville, Herkimer county. (S'a'f Collection.) 137. 11. LINGULA CRASSA (71. s/*.). Pl. XXX. Figs. 8 a, b, c, d, e. Broadly ovate, with a subacute beak ; one valve more convex than the other, and some- what arched ; shell thick, marked by strong concentric elevated lines, without radiating striae. This shell is broad and regularly rounded in front, sloping abruptly to the beak. The thick shell and prominent concentric lines arc characteristic. The shell is black, and less brilliant than the Lingul.5; usually are. I have seen but one perfect specimen. Single valves and fragments are abundant in the limestone at Basin Harbor (Vermont). It. is also apparently the same species, in fragments and smaller individuals, which sometimes abound in the silico-argillaceous limestone intercalated among the slates east of the Hudson river near Troy, showing its geological range to be from the Trenton limestone through the Hudson-river group. Fig. 8 a, b. View of both valves of this species. Fig. 8 «. View of the edge of both valves, closed ; one being more convex than the other, and slightly arched. Fig. 8 d. A larger specimen, apparently of the same species, somewhat crushed. Fig. 8 «. A smaller specimen, apparently of the same species. Positionand locality. This species occurs at Middleville, in the central part of the Trenton limestone ; also in the same rock at Basin Harbor and Crown Point on Lake Cliamplain. A species, similar or identical, in limestone among the shales of the Hudson-river group, near Troy. TRENTON LIMESTONE. 99 138. 2. ORBICULAI FILOSA («. 5;3.)- Pl. XXX. Figs. 9 a, b, c, d. Orbicular ; one valve more or less convex ; apex marginal ; surface radiated with numerous fine elevated threadlike stria;, wliich are more or less prominent, depending on cxfolialioii of the shell; intermediate stria; coming in between the otlmrs as they recede from the beak, but the stria; are not bifurcate. It is with some hesitation, that I refer this shell to the Genus Orbicula, since it presents some variation from the usual type. The young specimens are very convex, almost conical, but gradually become depressed and expanded as they increase in age and size. A single specimen, which is partially exfoliated, presents the marks of three visceral or muscular impressions, arranged somewhat like those of the Crania ; but since the shell differs as widely from types of that genus, as it does from Orbicula, I should scarcely feel authorised to place it under that genus, in the present state of our knowledge regarding it. The strongly striated surface presents a deviation from the general character of shells belonging to Lingula or Orbicula ; but it is otherwise of the same texture — black and glossy, as those shells. It likewise occurs associated with them, proving tbat its habit was similar, deviating no more from these genera than they do from each other. As the shell exfoliates, the surface becomes smoother, and the striae are nearly lost, except upon the margins. " ^ .. Fig. 9 a. A young shell; very convex or obtusely conical in form. Fig. 9 6. A larger shell, less convex than the last : when exfoliated near the beak, the marks of the muscular impressions are visible, similar to those of Crania. This portion is magnified. Figs. 2 c &, d. Two apparently full grown shells of this species; the form is much depressed, nearly flat, and the surface completely covered by fine stria;. These specimens bear a close resemblance externally to the Orthis ; but it is easy to discover, on examination, that they do not belong to that genus. Position and locality. These specimens occur in fine-grained dark limestone, near the upper termination of the Trenton mass. Tlipy are associated with Orbicula., Lingula, and some of the Conularia. Middleville. (*''«'« Collection.) 139. 3. ORBICULA LAMELLOSA ( n. .7;.). Pl. XXX. Figs. 10 a, b. Orbicular, depressed ; apex small, but little elevated, situated about one-third the breadth of the shell from the margin ; surface marked by elevated lamelliform concentric lines or ridges. • ( Fig. 10 a. Ventral view. b. Lateral view. ' 13' 100 PALEONTOLOGY OF NEW-YORK. This shell is nearly flat, with the exception of the small apex. The concentric lines appear to be made up of thin shelly laminae ; but in the single specimen we have, their edges are much broken. In some of its characters it approaches the O. rugata ( Silurian Researches, pag. 610, pi. 5, fig. 11), a species, or an analogue of^which, we find in great abundance in the Hamilton group ; the latter diflers, however, in the concentric ridges beinn- proportionally liner and less elevated, and the shell is much larger. The one under consideration is readily distinguished from any other in the Trenton limestone, by its slight elevation and subcentral apex. Position and locality. Middleville, in the shelly layers, lower part of the Trenton lime- stone. A rare species. 140. 4. ORBICULA TERMINALIS. Pl. XXX. Figs. 11 a, A, o, d. Orbinda termiiialU. Conrad in MS. Emmons, Geol. Report, pag. 395, fig. 4. Shell very obtusely subovate or orbicular ; ventral valve depressed convex, with a terminal or marginal apex ; dorsal valve very convex or subcorneal, with a central iipex, a broad depression and narrow slit on one side, extending to the margin of the shell opposite the beak of the ventral valve ; surface usually smooth, from exfoliation? Fine longitudinal or radiating striaj are also visible when the sliell is exfoliated ; these strife are sometimes punctate. A single specimen, apparently in a perfect condition, is marked by strong concentric elevated lamellae, giving a rough aspect to the surface. This fossil is easily recognized by its low convex suborbicular ventral valve, with a marginal apex. The opposite valve is less often seen, but it is as readily distinguished by the broad depression on one side of the apex, with the narrow slit in the bottom for the protrusion of the peduncle. This character is a very remarkable one, and serves to dis- tinguish this from all other known species of Orbicula in our strata. M. DE Verneuil, ill his PalcBontology of Russia and the Ural Mountains, has described and figiu'ed a species of Orbicula ( the 0. reversa, pi. xix.), which possesses the same remarkable feature of having the convex valve perf6rated for the protrusion of the ligament. This rare character is possessed by few species of the Orbicula ; the Orbicula lodensis of the Geological Reports of the Third and Fourth Districts of New-York, being the only one previously known to me; and in this one, the perforated valve is far less convex than in the one under consideration. The Russian species occurs in an ancient silurian sandstone in the vicinity of St. Peters- burgh, which is perhaps of the same age as our Potsdam sandstone. Associated with it is another species of Orbicula, and an Obolus, a genus allied to Lingula, and which in this instance occurs in great numbers, giving the Russian sandstone a micaceous appearance, TRENTON LIMESTONE. 101 as the small Lingula docs our Potsdam sandstone in the vicinity of Kccseville and other places. Fig. 1 1 a. Dorsal valvo, showing tho central apfi.x and lateral depression, which extends to the margin. Fig. 1 1 b. Ventral valve wilh marginal apex. Fig. 1 1 c. Lateral view of a perfect specimen. < Fig. 1 1 d. Ventral valve, marked with strong concentric lamellae ; apex marginal. Position and locality. This species is not uncommon at Middleville, Herkimer county, and perfect specimens are found at LowviUe. It occurs also at Watertown, Turin and Trenton Falls. (State Collection.) Of the forms of Lingula above presented, 1, 2, 3 and 6, are more nearly allied to each other, while all the others are clearly distinguishable. If the upper part of L. ricinijormis were exterided, and the shell a litile depressed, it would correspond wilh L. attenuata ; while if the proportions were altered in the opposite direction, or the beak depressed and sides expanded, it would correspond with L. aqnalis, and the transition from this to L. curta is scarcely perceptible. On comparison, however, of a considerable number of speci- mens, I am induced to believe that it is desirable to separate them ; calling attention to these differences, and thus inducing a comparison of a larger number of specimens. Vt'e may thus, hereafter, be able to point to some more decided characters, or show the gradations of the same species through all these forms. ' ' Presenting, as the LiNOULiE for the most part do, but few prominent features, and being seen but rarely, it is not easy to distinguish them, or to point out characters which mark specific distinctions, as many of those relied upon may be only indicative of different ages of the shells, or of different periods of their growth, and may even be dependent on other circumstances unknown to us. The other forms, beyond those noticed, are clearly distinct species, and easily recognized by the characters given. The Orbicul.e are usually associated with the Lingul.t:, in the fine-grained compact limestone ; the Conularia is also an almost constant associate of these shells, and rarely found in other situations. These sliells, so unlike in structure and habit, appear to have flourished under similar circumstances, and to have required the same kind of ocean bed or sediment. 102 PALJEONTOLOGY OF NEW-YORK. 141. 4. LEPT^NA ALTERNATA.* Pl. XXXI. Figs. 1 a - ;» ; and Pl. XXXI. A. Figs. 1 a - h. Lcptitna alternata. Conrad, Ann. Geol. Rep. New- York, 183S, p. 115. Strophomena alternata. Id. lb. 1839, p. Q3, table of organic remains. — — In. lb. 1840, p. 201 : regarded in this place as identical with Orthis alternata of SOWERBY. — — Id. lb. 1S41, p. 37. — — Emmons, Geol. Report, 1842, pag. 375, fig. 3. Leptcena alternata. Verneuil, Pal. of Russia and the Ural Mountains, 1845, pag. 225, pl. 14, fig. 6 a, b. — deltoidea. Id. lb. pag. 222, pl. 14, fig. 5 a, b. Compare Orthis alternata, Sowerby, Sil. Researches, pag. 63S, pl. 19, fig. 6. Also Strophomena tiasuta, Conrad, Jour. Acad. Nat. Sciences, Vol. viii. p. 260. — — Emmons, Geol. Report, pag. 403, fig. 3. Broadly semioval ; length and breadth about as 12 to 15 ; hinge line, in perfect speci- mens, a little longer than the width of the shell, slightly rellected at the extremities, which sometimes become short acute ears ; cardinal area narrow, the callosity of the ventral valve nearly filling the triangular foramen of the dorsal valve ; beak uniformly perforated with a minute circular opening ; dorsal valve depressed convex, sometimes more convex in the middle, suddenly deflected near the margin and flattened towards the cardinal line ; ventral valve concave, gradually or sometimes suddenly inflected towards the basal margin ; surface marked by fine rounded radiating striae, which alternate at unequal intervals with coarser ones ; strife increasing in number towards the margin of the shell, crossed by fine elevated concentric lines and a few imbricating lines of growth. In this species the striae are usually of two sizes, the coarser and more elevated ones having from four to six finer ones between ; the latter increase in number as they recede from the apex, and one of them, in the centre of the fascicle, becomes enlarged, and rises above the others. Some of the specimens figured are strongly marked individuals, where these characters are very distinctly preserved ; but there are many variations from the type of the species, and some others where it is diflicult to decide their true relations when we have not a series showing their gradations. The characteristic developments of the shell depend on the circumstances of its existence and the nature of the sediment. There are other ditTerences which are due to causes beyond our knowledge ; for, in the same locality, and where great numbers of them must have lived under precisely similar circumstances, we find considerable variation in character. In • This species was proposed by Mr. Conrad, under the name of Leptcma alternata, in 1838 ; and the name was known and continued in use in New-York till the publication of the final Reports ( the generic term Strophomena being substituted for Lepttcna ). When Mr. Murchison'b Siluriati Researches was received in this country, wc found that Mr. Sowerby had proposed the name of Orthis alternata for a lower silurian species, which is doubtless a true Leptjena ; and not knowing certainly that it was an identical species, Mr. Conrad subsequently proposed for our species the name of trentone?isis in his manuscript notes. M. de Verneuil has adopted the name Lepttena alternata in his PalrBontolugi/ of Russia and the Ural Mountains, and I have continued tlie same in the present work. If, hereafter, it should be found to conflict with the species of Sowerby, the specific term trentonensis may be adopted. The present name has precedence over all others applied in this country to the same species. TRENTON LIMESTONE. 103 the compaci limestones of New- York, wliere, in splitting the rock, a portion of the shell often exfoliates, we find a great deviation from the type of the species. The age of the shell also exerts considerable influence upon its external form. Tiie yotmg ones, or those of medium size, are usually symmetrical shells, moderately convex, and gentlj- curving towards the base. The stria; in such individuals are distinctly in fascicles of four to six, separated by stronger and more elevated single ones on either side ; as the shell increases, this uniformity in the arrangement often disappears, and the strioe appear of uniform size, or alternate irregularly. The concave or ventral valve, particularly in old specimens, has the striae nearly uniform in size. Plate XXXI. Fig. 1 a, A specimen of medium size, with the elevated strioe very distinctly marked, and the gradual enlarging of one of the intermediate smaller strice is shown as they recede from the apex. Fig. 1 i. A smaller specimen, presenting the characters of the species in a very perfect manner. Fig. 1 e. The inside of the dorsal valve of this species, showing, imperfectly, the visceral impression near the beak, and the papillose surface of the shell. The alternation of larger stri.-B with fascicles of smaller ones is quite distinct. Fig. 1 d. An individual of larger size, having the essential features of the species well preserved. This specimen is much more convex in the centre, and more abruptly curved in front, than either of the preceding. In the four figures above, the width considerably exceeds the height of the shell ; but this character is not constant. Fig. 1 e. The dorsal valve of another species; the length and breadth are about equal, and in this respect only does it differ from the preceding ones. The larger and more elevated striae alternate precisely in the same manner with four to six smaller ones, the whole being crossed by fine concentric slightly undulating lines. Fig. I /. A specimen having almost precisely the same form as 1 e ,• but the larger striae are not .so prominent, and the intermediate smaller ones not as regular as in the last species. This character, taken in connexion with the deviation in form, has been regarded as indicating a distinct species ; but it is clearly identical with those previously noticed, showing no greater difference in regard to the strire than is observed in others of the same form as 1 a, b, which will be shown on the succeeding plate. The foregoing figures represent the principal forms found in the Trenton limestone in the State of New- York. In western localities of rocks of the same age, this species assumes a greater variety of form, and has received several distinct names. Fig. 1 g. The dorsal valve of this species, from the shaly blue limestone of Ohio. The surface is well preserved, and the stria; very strongly marked : a few imbricating lines of growth are visible near where the curvature of the shell becomes abrupt. Fig. 1 h. Ventral valve of another specimen ; the radiating striae are nearly equal, the larger elevated ones, dividing the fascicles of small rays, being scarcely distinct, while on the dorsal valve they present the same distinction as in the last figure. The hinge view, of the same shell shows the deltoid foramen nearly closed, with the small perforation in the beak, which is enlarged in the upper figure. 104 PALEONTOLOGY OF NEW-YORK. Fig. 1 i. This shell is a representative of that known as L. ponderosa in Ohio. In form it resembles the two preceding, except that it is more deflected on the margin, with more distinct imbricating and squamose lines of growth ; the space between the two valves is also much greater, and the shell more massive. The stris upon both valves resemble the preceding ; but it often happens that those on the convex valve are more or less worn, so as to appear nearly equal. The character of the hinge, with the perforation in the beak, is the same. in both varieties. This variety of form evidently consists of old shells, which often show marks of injuries that have been partially healed ; they also bear evidence of wearing, and are frequently covered with corals, from which the lighter and younger shell is comparatively free. The view of the ventral valve and hinge line is precisely similar to the last; the lower figure is a lateral view, showing the great elevation of the dorsal valve and the abrupt curvature in front, with the strong imbricating lines of growth. Fig. 1 k. An elongated form of this species ; the dorsal valve showing the margin abruptly curved upwards from a little below the hinge line. The alternating striae are very perfectly re- presented, and the cardinal line presents the same characters as the previous ones ; the foramen in this one being scarcely closed, while the minute perforation in the beak is very conspicuous. This form corresponds precisely with 1 /, while there is a little deviation in the ahernation of the striae in that specimen. Fig. 1 m. The interior of the ventral valve, showing the visceral impression, and the two prominent toothlike processes between which the ligament of attachment passed out through the fora- men : these processes approach each other above, and produce the callosity, which, in most specimens, fills, partially or entirely, the foramen in the opposite valve. The entire inner surface is papillose, and more strongly so on the visceral impression. Specimens of this kind, revealing the internal structure of the species, are of rare occur- rence in the Trenton limestone in New-York, though not unfrequently found farther west. Fig. 1 n. The conve.ic valve of this species, with the shell partially exfoliated. The stronger radiating striae are very prominent, but the intermediate ones are obsolete except towards the hinge; the concentric elevated lines are, at the same time, very prominent. The shell is partially removed, so as to reveal somewhat of the internal structure. Although presenting some slight deviations in the striaa from the type of the L. alternata, 1 cannot find sufficient to characterize it as a distinct species. Plate XXXI. A. The elongated forms, figs, l/and k on the last plate, gradually assume a nasute shape, in which state lliey have been characterized as StropJiomena nasuta by Mr. Conrad. The following illustrations will show sufficiently well how the species under consideration assumes this form. Fig. 1 ffl. A .specimen which is contracted just below the ears and bent abruptly upwards, having tovrards the front several folds, and a more prominent one directly in front. Fig. 1 6. A lateral view of the same specimen, showing the abrupt and extreme deflection of the shell. Fig. 1 c. A specimen having the same general form as the last, but contracted and folded in front so as to present precisely the same form as the L. nasuia of Conrad. TRENTON LlMESTONi:. 105 The surfaces of both these specimens present the essential characters of the L. alUrnata, and the beak is always perforated. This is shown in the enlarged view of the hinge in fig-. 1 a, whieli at the same time shows the foramen not quite closed. This nasutc feature is often connected with a single elevated ridge, or more prominent stria, much longer than the others, and extending from the base to the beak of the shell. Tliis appears very distinctly in the two preceding specimens ; but to show that this character is common to the species, the specimen fig. 1 d is represented, showing a prominent line down the centre, while the shell is totally destitute of the other characters of S. nasula, being scarcely convex and very regularly somioval. Figs. 1 c,f,g&h. These figures represent a series of the younger shells of this species, as they occur in the compact limestone of Middleville, Little Falls, Trenton Falls, and other places. The strinj often alternate irregularly, and sometimes they are of nearly equal size. This variation ol'tcn arises in part from exfoliation of the sliell ; but if a number of specimens are examined, there will be found a gradation in the strite, and some of them exliibit the typical characters of the species. These figures present also a gradation in form from the perfectly semioval to the elongated or nasute front, showing very conclusively that this character cannot be relied upon in the .distinction of species.* ~ Position and locality. This is one of the species, which, (omiiu'iicing its existence prior to, or at the epoch of the Trenton limestone, continues in great ruinibers throughout that rock, and, though not appearing in the Ulica slate, reappears in the Hudson-river group in immense numbers, several thin strata in the upper part of this group being composed almost entirely of the shells of this species. The forms 1 e,f, g Si, h, of Plate XXXI. A., are the most common and abundant in the Trenton limestone, and some of these are met with in almost every locality : the other forms are more rare. It is aluindant at Middleville, Little Falls, Jacksonburgh, Herkimer, Trenton Falls, Sugar River, Turin, Lowville, Watertown, Plattshurgh, Glen's Falls, &c. The same species, in forms like 1 g, h, i, k, Plate XXXI., and others, are abinidant at Maysville ( Ky.), Cincinnati and Oxford (Ohio), Madison ( Indiana), and in Tennessee. (State Collection.) • 1 liave been induced to dwell so loiii< upon tliis s|jc'cie.s, I'rom the fact of its variable form, and other characters which have been the source of much annoyajice to amateurs, and no little trouble to myself, since I have it from diflereut persons and localities, under at least six or eight dilierent names. [Pal-eontology.] 14 106 PALEONTOLOGY OF NEW-YORK. 142. 5. LEPT^NA CAMERATA.^ Pl, XXXI. A. Figs. 2 a, b. Strnphomena camerata. Conbad, Jour. Acad. Nat. Sciences, pag. 254, pl. 14, fig. 5. Compare Lepticna cleltoidta, Conrad, and the figures of that species in tliis work. Suborbicular ; dorsal valve very ventiicose in the middle, abruptly elevated in front ; disk and umbo nearly flat, or depressed convex ; surface marked by numerous crowded unequal radiating strise ; extremities of the hinge line slightly salient, and constricted below ; apex scarcely projecting beyond the hinge margin. The shell is removed from this specimen, except on the disk of the dorsal valve. Near the extremity of the hinge line, and on the disk, there are some obscure wrinkles, which induce me to believe that this shell is only a variety of L. deltoidea of Conrad. The specimen figured, however, I believe to be the original one from which Mr. Conrad has drawn his description, otherwise I should not have ventured a separation from L. deltoidea. Fig. 2 a. Lateral view of the specimen, showing the extreme convexity of the shell in the centre, and the nearly fiat disc. Fig. 2 b. Front view, showing the great deflection ; the surface is puncto-striate, from being denuded of the shell. Position and locality. In the Trenton limestone at Trenton Falls. (State Collection.) 143. 6. LEPT^NA DELTOIDEA. Pl. XXXI. A. Figs. 3 a, b, c, d, e. Lepteena deltoidea. Conrau, Ann. Geol. Report, 1S38, p. 115; Strophomena deltoidea. Id. lb. 1839, p. 64; 1841, p. 37. — — Vanuxem, Geol. Report, 1842, pag. 4G, fig. 2. — — Emmons, Geol. Report, pag. 389, fig. 2. Shell semioval or deltoid ; hinge line extending beyond the width of the shell ; dorsal vjilve convex, abruptly deflected at the margin, except a small portion in the centre, which is often produced in front ; surface of tiie disc marked by numerous irregularly concentric undulations or wrinkles, which are crossed by fine equal radiating striae ( one or two of these striffi, in the middle of the shell, more prominent than the others ) ; sides of the shell marked only by the finer stria; ; sometimes, in well marked specimens, the striae are distinctly alternating ; disc elevated in the middle ; beak scarcely projecting beyond the cardinal line. This shell dificrs from the preceding species, in the usually more convex area or disc of the dorsal valve, and the linguiform extension in front, which, though existing in the nasute forms of the L. alternata, is not accompanied by the concentric wrinkles. This feature characterizes nearly all the specimens I have seen from Trenton Falls. TRENTON LIMESTONE. 107 TIi<^ following fiGfiirps prpscnt some variety of form, which this species assumes, under iliflerent circmustaiices and in distant localities : Fig. 3 a. A specimen showing but a slight difference from the last described species. It is marked by distinct concentric wrinkles upon the disc ; is finely striated, with more prominent elevated ones alternating with every four, five or six of the smaller ones. In this respect it partakes of the characters of the specimen fig. 1 i, which appears to me clearly referable to L. alternata. Fig. 3 I. This specimen presents the same form as the last, except that it is more produced in front. Tho concentric wrinkles on the front are perhaps more distinct, and the shell is contracted more abruptly just below the extremity of the cardinal line, producing small acute ears. Fie. 3 c. Lateral view, showing the ele\-ation of the shell. Fig: 3 . The specimen under examination has perhaps suflfered some distortion, but it is remarkable for the nearly ec[ual areas, and the almost entire flatness of both valves. In its anguldted and extended cardinal extremities it resembles tlie succeeding species ; but that shell is much longer in proportion to its width, and the striae are less sharply crenulated. * Mr. Conrad has kindly placed this and some other western specimens at my disposal, for the purpose of instituting a comparison between the eastern and western species of our lower formations. [ PaL/Eontologv.] 15 l! 114 PALJEONTOLOGY OF NEW<.YOEK, Fig. 6 a. View of ventral valve. Fig. 6 b. Cardinal view of the same shell. Position and locality. Associated with the last species, and others, in the lower shaly limestone at Mineral Point ( Wisconsin). 151. 14. LEPT^NA PLANOCONVEXA ( «. SJ3.). Pl. XXXI. B. Figs. 7 a, i, c, d. Shell resupinate, sub-planoconvex, often distinctly inequilateral and oblique ; ventral valve moderately convex ; dorsal valve nearly flat or slightly concave ; cardinal line extended considerably beyond the width of the shell, and often produced into small acute ears ; surface marked by rather coarse radiating stria;, which bifurcate towards the margin of the shell ; apex usually, and perhaps always, perforated ; foramen closed ; cardinal area narrow. The most obvious characters of this shell are its resupinate form, the nearly flat dorsal valve, and frequent inequality of the two sides, or the greater extension of the cardinal line on one side. In these features alone it is dissimilar to all the other species of the genus in the lower strata. In its nearly flat valve, it approaches to the Orthis ; while the extension of the cardinal line, and closed foramen, are characters belonging to LEPT.a:NA, as well, also, as its general habit, which is different from the true Orthis. In some of its varieties, and particularly in the ventral valve being flat near the beak, it resembles the last species, but differs essentially from it in the coarser nearly equal strisp and absence of concentric elevated lines, as well as other important characters. Fig. 7 a. View of the dorsal valve, with one of the cardinal extremities produced beyond the other ; tliis feature is not due to wearing, but is the natural form of the shell. Fig. 7 b. View of a smaller specimen, more nearly equilateral. Fig. 7 c. Profile view of the shell. Fig. 7 d. Cardinal view of the first specimen. Position and locality. This species occurs associated with the two last, having a very extensive geographical range. It is known in numerous localities in Ohio, Indiana, Ken- tucky and Wisconsin. (Stale Collection.) tRENTON MMKSTONEi 1 15 152. 15. LEPTiENA TENUILINEATA. Pl. XXXI. B. Fig. 8. Strophomena tenuilineata. Conbae, Jour. Acad. Nat. Sci. Philadelphia, ISli, Vol. vni. p. 259. " Semioblong-oval, with minute crowded radiating lines ; cardinal extremities slightly salient and angulated ; one valve slightly convc.v, the otli'-r flat. " Distingiii.shable from its congeners of the Trenton limestone by the slight convexity of the inferior valve, and the extreme fineness of the radiating lines. The outline is alstJ different, being wider at the base than any other Trenton species. It resembles Orthis comprcssa (Sowerby), except in outline being much longer in proportion to the width. " Occurs in Trenton limestone." The above is quoted from Mr. Conrad's description and remarks, not having seen the shell myself. The drawing is given from his figure, marked with this name, and is doubtless correct. It is evid(;ntly a rare species, as I have never met with a single individual. The Orthis compressa of Sowerby, to which Mr. Conrad compares this species, is a Lower Silurian fossil, corresponding very nearly in position to this one. 153. 16. LEPTiENA SUBTENTA. Pl. XXXI. B. Figs. 9 a, b. Strophmiiena subtcnta. Conr.id, M.S. and figure. Resupinate, scmioval ; ventral valve convex in the middle ; cardinal extremities deflected, somewhat abruptly curving towards the margin, and flattened on the umbo ; surface marked by fine equally bifurcating stria?, which are crenulated ])y concentric lines, obliquely wrinkled on the cardinal margin ; interior of the hinge showing two projecting toothlike processes, with a narrow space between them for the passage of a ligament ; lateral teeth spreading widely. I find, among the drawings of Mr. Conrad, the figure of a Trenton species, with this name attached. I have not seen the same in New-York, but the specimen figured is from a western locality. It bears all the essential marks of the species cited, and I have therefore introduced it under that name. It will, doubtless, be found again in New- York. The cardinal margin bears some resemblance to CHa;TETES, but a careful examination does not show any spires. The strong oblique wrinkles form a distinguishing feature. Fig. 9 a. View of the dorsal valve. Fig. 9 b. Interior of the hinge margin. Position and locality. In the Blue limestone of Ohio, associated with Leptccna alternataf L. sericea and Orthis testudinaria. Oxford ( Ohio). Trenton Falls, on the authority of Mr. Conrad. 15* 116 PALEONTOLOGY OF NEW-YOKK. 154. 17, LEPTjENA ( Species undetermined ) . Pl. XXXI. B. Figs. 10 a, b, c. Semioval ; greatest width i|, height j\ of an inch ; cardinal line scarcely equalling the greatest width of the shell below ; surface marked by fine radiating striae, which are crossed by fine concentric lines ; striae upon the ventral valve equal and uniform in size ; those on the dorsal valve consisting of larger striae with one or two finer ones between, a single one, larger than tlie others, extending from the beak to the base of the shell ; beak imperforate ; foramen not closed. This species presents many characters in common with L. alternata, and is perhaps only the young of that shell. The character of the surface markings is very analogous, differing uo more than might be expected between the young and old individual. The callosity of the ventral valve, whicli, in most of the LEPT.a;NA, nearly fills the triangular foramen, presents in this case a narrow channel or groove, leaving a passage for the extension of the tendinous peduncle. The imperforate beak shows a distinct small point, projecting beyond the cardinal line. The open foramen is probably due to the youth of the individual, as it often happens that this passage becomes closed with age. Whether the perforation in the beak may become developed as the shell advances in age, I am unable to determine. The specimens under consideration are apparently young shells, though I have not been able to trace their gradation to the larger forms of L. alternata, or any other species. The careful examination of six well preserved specimens shows a uniform development of the characters above given. Fig. 10 a. Ventral valve of this species, showing the equal radiating striffi. Fig. 10 6. Dorsal valve, with unequal strise. Fig. 10 c. Cardinal area, and the same enlarged, showing the open foramen and imperforate beak. Position and locality. This shell occurs in the same situation and association with L. alternata, L. sericea, and other species of the genus. There are, in addition to the foregoing, one or two undetermined or obscure species, which require further investigation before they can be regarded as established. TKENTON LIMESTONE. 117 155. 2. ORTHIS TESTUDINARIA. Pl. XXXII. Figs. la-/. Orthis testudinaria. D.ilman, Vet. Acad. Hand. Stockholm, 1827, p. 115, t. 2, f. 4 a, b, c, d, e. Trigonotrctia testudinaria. Bronn, Leth. Geognostica, pag. 82, tab. 3, fig. 2. Orthis testudinaria. Hisinger, I'ct. Suecica, 1S37, pag. 71, lab. 20, fig. 11 a, b, c. — — 7 SowERBY in Sil. System, 1S39, pag. 640, pi. 20, fig. 9. — — CoNR.\D, Ann. Geol. Report of 1839, p. 63 ; 1S40, p. 201 ; 1841, p. 37. Orthis striatula, Conb.vd in MS. Emmond, Geol. Report, 1842, pag. 394, ill. 105, fig. 3. Orthis testudinaria 7 Emmons, lb. pag. 40 1, fig. 4. Suborbicular, plano-convex ; cardinal line straight, shorter than the widtli of the shell ; dorsal valve convex, much elevated towards the beak, often with an elevated ridge down the centre; beak small, slightly incurved; ventral valve (lat, or with a longitudinal depression along the centre, wliich often produces an emargination in front ; cardinal area small ; foramen small, triangular ; surface covered with fine stria;, whicli bifurcate towards the margin, and are crossed by elevated threadlike lines, giving them a crenulated appearance. This species is variable in some respects. Nearly all the specimens from New-York have a regularly depressed-convex dorsal valve, with a flat or sometimes slightly convex ventral valve ; while those from Ohio, wliich are specifically identical, have very frequently an elevated longitudinal ridge on the dorsal valve, and a depression along the flat or ventral valve. These characters do sometimes occur in the Trenton specimens, but not often. In the western specimens the striae are usually more prominent than in those of New- York, and the shells likewise attain a larger size. This species is exceedingly abundant in the Trenton limestone, being, with the Lcptama sericea, the two most abundant fossils in the rock. It often covers entire surfaces of the thin strata, both as perfect specimens and as separated valves. It appears to be in equal abundance in nearly all the western localities of the same rock. A comparison of a Swedish specimen of Orthis testudinaria with those of New-York, shows no essential difference ; the former being a little more elongated, and the ventral valve more convex than in the prevailing forms of the Trenton limestone. Fig. 1 a. Ventral valve, showing the beak of the dorsal valve and the foramen. Fig. 1 b. Profile view of the same shell, showing the convexity of the dorsal valve : the same is shown in the cardinal view, 1 d. Fig. 1 e. View of the dorsal valve, showing the small projecting beak. Fig. 1 e. A smaller specimen of the same species. Fig. 1 / The interior of the dorsal valve, showing the toothhke processes margining the foramen, and projecting forwards into the shell. Fig. 1 g. The interior of the ventral valve, showing the visceral impression, and the two lateral tooth- like processes which imite with the processes of the other valve. Fig. 1 /;. Cast of the dorsal valve, showing the two visceral impressions, one on either side of a central elevated ridge. Figs. 1 i, k, I. The same species, from the Blue hmestone of Ohio. •l 118 PAL^ONfOLOGV OF NEW-YORK. Position and locality. This species occurs in every part of the Trenton limestone, ap- pearing near its base, and continuing throughout : it also appears in the Hudson-river group, in almost equal numbers. (State Collection.) 156. 3. ORTHIS SUB^EQUATA. Pl. XXXII. Figs. 2 a, b, c, d, e,f. Orthis stiiieguata. Conrad, Proc. Acad. Nat. Sci. Philadelphia, 1S43, Vol. i. p. 333. Compare Orthis parva, var. avellana. Verneuil, Pal. Russia & Ural Mountains, 1845, p. 188, 1. 13, f. 3 & 4. Semioval or subglobose ; length and breadth about equal ; valves ventricose, subequal, regularly rounded in front ; cardinal line about equal the width of the shell ; area rather large ; dorsal valve very convex, with a prominent elevated centre ; beak extended, scarcely incurved ; ventral valve regularly convex, with scarcely a depression in the centre ; surface covered with crowded, radiating, nearly equal stria;. Length yV of an inch ; breadth a little greater. This shell bears some resemblance to the 0. testudinaria, but differs in the nearly equal convexity of the valves, the larger area, and more crowded striae, which do not exhibit the fine concentric lines of the latter species. Well defined specimens have not been found in New-York : the one figured is from the Collection of Mr. Conrad. From its general re- semblance to 0. testudinaria, it would be easily overlooked ; and since it occurs in the same association at the West, it is not improbable but it will be found in New- York. Fig;. 2 a. Ventral valve, showing the projecting beak of the dorsal valve, and a portion of the cardinal area and foramen, which is a narrow slit extending to the beak. Fig. 2 b. View of the dorsal valve of the same specimen. Fig. 2 c. Profile view of the same, showing the nearly equal convexity of the valves. Fig. 2 d. Cardinal view of the same, showing a slight depression in the centre of the ventral valve. Figs. 2 e, / Figures of a smaller specimen ; the ventral valve being less convex than in the older specimen. Position and locality. 'This species occurs at Mineral Point (Wisconsin), in the Blue limestone, associated with Lcptcena sericea, Orthis testudinaria, Delthyris lyiix, and other Trenton limestone fossils. 157. 4. ORTHIS BELLA-RUGOSA. Pl. XXXII. Figs. 3 a, b, c. Orthis bella-riigosa. Conrad, Proc. Acad. Nat. Sci. Philadelphia, 1843, Vol. i. p. 33. Semioval ; length and breadth about as 7 to 8 ; valves almost equally convex ; ventral valve with a narrow depression along the centre, which becomes indistinct towards the margin ; beak of the dorsal valve considerably extended beyond the cardinal line, scarcely TRENTON LIMESTONE. 119 incurved ; surface marked by fine, close, radiating striae which arc unequally bifurcated towards the margin, and transversely marked by prominent imbricating stiuamosc lamella;, which alternately advance and retreat in passing over the striae and the spaces between them. Width half an inch ; length less than half an inch. This species is, in form, much like 0. subaquata ; but the valves are less convex, and it is readily distinguished by the squamose striie, which give the surface a rugose appearance, differing from all the other species of Orthis in this rock. Fig. 3 a. Ventral valve. Fig. 3 b. Dorsal valve. Fig. 3 c. Profile view, showing the nearly straight projecting beak of the dorsal valve. Fig. 3 d. Cardinal view, showing the large triangular foramen. Fig. 3 e. An enlarged portion of the surface, showing the imbricating squamose lamclliB. Position and locality. This unique and beautiful species occurs with the preceding, and others which are common to the Trenton limestone of New-York, though it has not yet been noticed within this State. 158. 5. ORTHIS DISPARILIS. Pl. XXXII. Figs. 4 a, b, c. Orthis disparilis. Conrad, Proc. Acad. Nat. Sciences, 1S43, Vol. i. p. 333. Semicircular, with about 28 regular rounded stria;, more than half of which reach the beak, the intermediate ones commencing on the umbo ; striaj crossed by finer concentric elevated lines ; ventral valve flat or slightly concave, depressed along the centre, which produces a slight curvature in the edge of the shell ; margin of the shell regularly rounded from the extremities of the cardinal line ; area large ; foramen a narrow nearly linear slit, reaching to the apex. This peculiar shell is readily identified by its greatly elevated or subconical dorsal valve, and quite flat or slightly concave ventral valve. The stria are stronger than in the preceding species, and uniformly crossed by concentric lines as in 0. testudinaria. The dorsal area is proportionally larger than in any other species except 0. triccnaria, which is a larger and more elongated shell. Fig. 4 a. Ventral valve. ' . Fig. 4 b. Dorsal valve. Fig. 4 c. Profile view, showing the great disproportion in the size of the valves. Fig. 4 d. View of the cardinal area and foramen. Position and locality. This species occurs at Mineral Point ( Wisconsin), associated with the preceding species. I have also seen it from Cincinnati, associated with numerous species of Brachiopoda typical of the Tienton limestone. 120 PALEONTOLOGY OF NEW-YORK 159. 6. ORTHIS PERVETA. Pi,. XXXII. Figs. 5 a, b, c. Orthis pervcta. Conrad, Proc. Acad. Nat. Sci. Philadelphia, 1843, Vol. i. p. 333. Transversely suboval, somewhat wider below than the length of the hinge line ; valves slightly ventricose, nearly equal ; surface marked by numerous fine radiating strioe, which bifurcate on the umbo ; ventral valve with a slight almost imperceptible depression along the middle ; dorsal valve with a broad elevation in front, producing a sinuous margin ; cardinal area partially common to both valves, as likewise the deltoid foramen. Length about one third of an inch ; breadth nearly half an inch. Fig. 5 a. View of the ventral valve, and area of the dorsal valve. Fig. 5 b. Cardinal view of the same specimen. Fig. 5 c. Profile view, showing the width of the area, and the projecting beaks on both valves. Fig. 5 d. Cardinal view magnified, showing that the area and foramen are partially common to both valves. I have adopted this species, with the three preceding ones, from Mr. Conrad, as they occur associated witii several well known Trenton species at Mineral Point ( Wisconsin ) . The associated species more particularly are the Orthis tricenaria, 0. pectinella, 0. tes- tudinaria, Leptana sericea, Delthyris lynx, 8fc. 160. 7. ORTHIS ^QUIVALVIS ( n. sp.) . Pl. XXXII. Figs. 6 a, b, c. Subrotund ; valves almost equally convex ; length nearly equal to the breadth ; sides contracted just below the cardinal line, which is less than the greatest width of the shell ; area narrow ; foramen small ; dorsal valve differing from the ventral, in the beak being slightly extended, and scarcely curved over the foramen ; surface marked by about twenty rather sharp radii, with deep intermediate spaces ; radii strongly marked entirely to the beak, and becoming bifid or trifid towards the middle of the shell. This species is easily recognized, from the almost perfectly equal valves, the beak of the dorsal valve being only a little more extended than that of the ventral valve. The strong radiating striae or costae, which are usually bifid or trifid, are marked as if by the bases of short spires, or of squamosc projections of the shell, which, in perfect specimens, indicate a character much like Atrypa aspera. Fig. 6 a. View of the ventral valve, showing the beak of the dorsal valve, a small portion of the area, and triangular foramen. Fig. 6 b. View of the dorsal valve. Fig. 6 c. Cardinal view of the same, showing the equality of the valves. Position and locality. In Trenton limestone, Middlcville? Cincinnati. TUENTON LIMESTONE. ^ 161. 8. ORTHIS FISSICOSTA ( n. 5;>.) . Pl. XXXII. Figs. 7 a, 6. Compare Orthis ealligramma. Dalman, Hisingeh, de Verneuii.. Ort/iis actonue. Sowerby in Murchison's Sil. System, pag. 030, pi. 20, fig. Ifi. Semioval, with the cardinal line somewhat less than tiie width of the shell ; area narrow ; foramen narrow, triangular, reaching to the apex ; dorsal valve moderately convex, with the beak extending and slightly incurved ; ventral valve moderately convex in the middle, and depressed at the sides ; surface marked by angular costa;, which become bifid and trifid on the centre or towards the margin of the shell ; number of costa; about 19 or 20. This shell, in its general form, reseml)les the 0. ealligramma ; but it is clearly a distinct species, judging from a single European specimen in my possession. The bifid, trifid, and even cjuadrilid costte are an obvious dill'erencc, thougli such a change may take place in the costaj of 0. ealligramma. The costa are fewer on this species, and more elevated ; the ventral valve is convex, while in that species it is flat and slightly depressed in the centre ; the dorsal valve is less convex in our species, though the specimen is somewhat crushed. In the divided character of the costae, this shell resembles the Orthis actonix cited above ; but our specimen is smaller than the one figured by Sowerby, and has a greater number of costae (19 on the dorsal and 20 on the ventral valve, while that one has 14) . A com- parison with a single specimen of 0. actoniee shows the costEe to be more distant in that species than in ours. Fig. 7 a. View of the ventral valve, showing a portion of the area and beak of the dorsal valve. Fig. 7 b. Profile view of the same, showing the projecting beak of the dorsal valve. The dorsal valve has been crushed, so that the profile view does not give a correct idea of its convexity. Position and locality. This species occurs with the preceding ones in the Blue limestone of the West, but it is unknown to me in New-York. I obtained but a single specimen near Cincinnati, showing that the shell is comparatively rare. 162. 9. ORTHIS TRICENARIA. Pl. XXXII. Figs. 8 a, b, c, d, c. Orthis triccnaria. Conrad, Proc. Acad. Nat. Sciences, 1S13, Vol. i. p. 333. Semioval ; length and breadth nearly equal ; cardinal line straight, equal to, or greater than the width of the shell ; area very broad ; foramen long, sublineor ; dorsal valve sub- conical, with the apex much elevated and produced, though scarcely incurved ; cardinal margins sloping very obliquelj' from the beak ; ventral valve flat, regularly rounded from the extremities of the hinge line ; surface marked with from 16 to 32 rounded simple radii, with spaces between equal to the radii. The most striking character of this shell, and one which will serve to distinguish it from any other Orthis known to me in New-York, is the great elevation of the dorsal valve, and remarkably broad cardinal area; the ribs are always simple, continuing distinct quite to the apex of each valve, and gradually enlarging towards the base ; the foramen is some- what linear in perfect specimens, and continues quite to the beak. I Pal.-eontologv.] 16 122 PALEONTOLOGY OF NEW-YORK. Fig. 8 a. View of the ventral valve and area ; the specimen imperfect. Fig. 8 b. laterior of the dorsal ^alve, showing the cardinal area. Fig. 8 c. Exterior of the dorsal valve. Fig. 8 d. Interior of the ventral valve, shovying the toothlike processes and visceral impression. Fig. 8 e. Profile view of a perfect specimen. This is a rare sliell in New-York, and I have been able to obtain but few specimens, and these for the most part imperfect. Its associates in the strata are Orthis testudinaria, Ltptana sericea, ^trypa triplex, Ceraurus pleurexanthemus, ^c. Position and locality. In New- York, it occurs in the lower part of the Trenton limestone, associated as above, at Middlcville. It is found at Mineral Point (Wisconsin), apparently in the higher part of the same rock. {ty tlie external characters, the internal markings being quite distinct. The form of a perfect specimen is subquadrate, as shown in the figures ; the surface is evenly marked by radii which bifurcate twice, very rarely three times, before reaching the margin : the upper lateral ones curve upwards, so as often to run out uiJon the cardinal line, or the rounded slope near its extremity. This character is never observed in either of the following species. The visceral impression in the dorsal valve is subquadrangular, and broad below, the base being nearly on a straight line. The foramen of the ventral or convex valve is partially filled by a thick medial footh, which projects above the jilane of the area, and is deeply striated on the two sloping upper and outer sides. By comparing the parts indicated with either of the two following species, there will bo no difficulty in deciding as to which the individual belongs. Fig. 1 a, b, c. Three views of the dorsal valve, showing gradation in the size of the shell. Fig. 1 d, e. Profile views, showing the nearly equal elevation of the beaks. Fig. I /, g. Front views, showing the slight elevation produced by the sinus in the ventral valve. Fig. 1 h, i. Ventral valves, showing the slight depression along the centre of the shell. Fig. 1 !c. Cardinal view, showing the area, foramen, etc. Fig 1 I. Exterior of a large dorsal valve somewhat flattened from compression. Fig. 1 m. Interior of the same, showing the form of the visceral impression and the marks of the external radii, which terminate near the margin. Fig. 1 n. Dorsal area and foramen. Fig. 1 0. Interior of the ventral valve, showing the narrow area and foramen, with the projecting medial tooth, which is enlarged in the upper figure. The impressions of the external radii are visible but a short distance from the margin on the inside of the shell. Position and locality. This is a common species in nearly all the western localities, being * known at Maysville ( Kentucky) , Cincinnati and Oxford (Ohio) , Madison ( Indiana) , and ^ other places, associated with other .spcxies of the genus, and with IjEPTa:na. p .^ TRENTON LIMESTONE. 127 169. 16. ORTHIS OCCIDENTALIS ( n. .?/).) . Pl. XXXII. A. Figs, 2 « - m; and Pl. XXXII. B. Figs. I a - i. '^ . Resupinate, transversely somewhat oval, or longitudinally scmioval ; length and breadth about as 5 to 7 ; cardinal line equal to the greatest widtii of tlic shell ; area large, triangu- lar, partially common to both valves ; foramen narrow, triangular, reaching to the apex of the dorsal valve ; dorsal valve convex towards the beak, and usually flattened or slightly convex towards the margin (in old shells a broad depression in front) ; beak much elevated, straight, not incurved ; ventral valve regularly convex, with a slight depression along the centre ; beak slightly projecting beyond the cardinal line, and incurved ; surface marked by subangular radii, which bifurcate at one-half or two-thirds the distance from beak to • ' ^» base ; radii crossed by fine sharp elevated concentric lines, which are usually well preserved in the spaces between (ho radii. This species, in some of its phases, approaches in general aspect to the last, but diflerg in essential particulars. The length from beak to base is proportionally less than in the last ; the depth of the two valves together, when not compressed, is greater ; the beak of the dorsal valve is more elevated, the area larger and foramen longer ; the beak of the " ventral valve is likewise a little more incurved ; the radii are stronger, and do not bifurcate near the beak ; the concentric elevated lines are sharper and finer ; the striaj are straight - and direct, the last ones not bending upwards as in the O. suhquadrata. As the shell be- comes advanced, the dorsal valve presents an increasing depression towards the margin, which finally becomes a broad, not distinctly defined sinus. At the same time the slight depression iii the centre of the ventral valve, similar to that in the last species, does not reach the margin, and finally becomes obsolete. The slight elevation in front, shown in the last, is exactly reversed in this species. These characters, when once observed, will not fail in enabling the student to identify the species, and to distinguish it from any otiicrs in the same geological position. The internal structure is not as well known as in the last, the interior of the dorsal valve not having been seen. The interior of the ventral valve corresponds in general character to the last ; the small medial ventral tooth does not, however, reach as high as the plane of the area, and it is thin and sharp, while the last is thick. The interior surface is marked , nearly to the beak with the impressions of the external radii ; while in the last, these markings reach only a short distance from the margin. Plate XXXII. A. Figs. 2 a - f, are illustrations of a series of this species, beginning wiih the smallest recognized speci- mens, and passing througli the several grades, till the increasing rotundity of the ventral valve towards the umbo, rises above the bcnk of the dorsal valve. Figs. 2 g, h. Profile views of several specimens as above. The strong, nearly straight, and greatly elevated beak of the dorsal valve is well shoAvn, as is also the slightly incurved beak of the ventral valve ; the latter becoming more gibbous as the shell advances in age. .« . 4 « 4 128 PAL-EONTOLOGY OF NEW-YORK. Fio^. 2 i, k, I, m. Front views, showing the increasing sinus of the dorsal valve as the shell becomes older. Plate XXXII. B. Fin-s. 1 a, b. Cardinal views of a young and old specimen of Orthis occidentalis. Fig. 1 c. Ventral valve of an imperfect specimen, partially showing the mterior of the dorsal valve, which is strongly marked by the external radii. Fig. 1 d. Profile view of a large specimen. Flo's. 1 e,f, g. Views of ventral valves. Figs. 1 A, i. Interior of ventral valves of the same species, showing the medial tooth and the marks of the external radii. Position and locality. This species is associated with the preceding, in considerable numbers, in the Blue limestone of the West ; being found at Maysville ( Ky.), Cincinnati and Oxford (Ohio), Madison (Indiana), and other places. (State Collection.) 170. 17. ORTHIS SINUATA ( n. sp.) . Pl. XXXII. B. Figs. -la-s. Semioval, with a sinus in front ; cardinal line scarcely equal to the width of the shell ; dorsal area large, triangular ; foramen triangular, reaching to the beak, the upper margins sloping rather abruptl)' from the beak ; ventral area narrow linear, foramen broad triangu- lar, with a distinct medial tooth, which reaches as high as the area ; dorsal valve convex, its greatest elevation at the point of the beak, which is acute ; a depression along the centre, which becomes a sinus in older shells ; ventral valve regularly convex in young specimens, gibbous, somewhat emarginate and elevated in front in older specimens ; surface marked by strong, regular, rounded striae, which bifurcate in a nearly imiform manner about half way to the base ; striae crossed by elevated sub-imbricating concentric lines. A few imbricating lines of growth are distinct towards the margin of the older shells. This species is distinguished from the last by the stronger and more prominent striae, which are likewise more regularly bifurcating. The beak of the dorsal valve is more elevated and acute, giving a greater height to the dorsal area. The ventral valve is about equally convex or gibbous with the last, while it never exhibits any depression along the centre. The depression or sinus in the dorsal valve is usually more abrupt, dei-per, and often accompanied by a corresponding elevation on the ventral valve, which does not occur in the preceding species. The young shells of the species under consideration are more gibbous than the last, and have the beak of the dorsal valve more elevated and acute, differing conspicuously in this respect from the previous one. The variations produced by age, and the difficulty of obtaining a series of specimens, often produce confusion in regard to these similar .species, and it will fro(|Uontly be found a (iifficnlt task lo make the proper disposition of specimens. TRENTON LIMESTONE. 129 In the young shells of this species, looking upon the ventral valve, the Leak of the dorsal valve is distinctly seen projecting beyond the umbo ; but as the shell grows older, this part of the ventral valve becomes gibbous, and projects beyond the line of tlie beak of the opposite valve. Figs. 2 (I, i, c, d. e. A series of specimens, illustrating the variations producrd by age. Figs. 2f, g, h. Profile views of specimens of different ages, shouing the gradual increasing rotundity of the ventral valve, and also the more acute beak of the dorsal valve as compared to the last. Figs. 2 i, k Front views of young and old specimens. Figs. 2 I, m. Cardinal views of young and old specimens. Figs. 2 n, 0 Ventral valves of a young and old specimen. Fig. 2 p. Interior of the dorsal valve, showing the form of the visceral impression, and the radii near the margin. Figs. 2 q, r. The two lower figures show a slight difference in the character of the visceral impression. Fig. 2 s. Interior of the ventral valve, showing the medial tooth, which is thicker and stronger than in the last species, and is connected with a strong medial ridge which is trifid below. The radii are only shown near the margin of the valve ; in which respect, also, it differs from the preceding species. Position and locality. This is equally abundant with the two preceding and (he following one, in many western localities. It occurs at Maysville ( Ky.) , and Cincinnati ; while it i.s less frequently found at Oxford (Oliio), and at Madison ( la.). 171. 18. ORTHIS SUBJUGATA ( n. .?/>.) . I^L. XXXII. C. KiL's. 1 a-m. Semioval, with the front somewhat produced ; cardinal line nearly equal the width of the shell ; dorsal area moderately large, triangular ; ventral area narrow, linear ; dorsal valve having its greatest elevation just below the beak, or sometimes at the point of the beak; sides somewhat depressed, often flcittened, with a deep broad mesial depression; ventral valve convex, gibbous on the centre and towards the imdjo ; surface marked by even rounded stria?, whicli are dichotomous and triciiotomous towards the margin ; con- centric lines not very conspicuous ; a few imbricating lines of growth visible towards the margin ; a mesial elevated ridge in older specimens. Tliis shell bears considerable resemblance to the last, except that the stria; are much finer, and the concentric lines less distinct. The beak of the dorsal valve is less elevated, .^, and the umbo of the ventral valve, in old shells, more prominent than in the preceding species. There is some variation in the length of the cardinal line, as compared with the width of the shell ; but in the one imder consideration, it is always proportionally more extended than in the preceding species. The sinus of the dorsal valve is also more distinct in the young shells, and is equally conspicuous in older ones. [Pal^ontolo(;y.J 17 4 130 PALEONTOLOGY OF NEW-YORK, This species differs from 0. Occident alls, in the absence of a depression on the ventral valve, as well as in general form, stri;c, and other particulars. It bears about the same relation to the last, that 0. suhquadrata does to 0. occidentalis. The distinctions here indicated are believed to depend upon essential differences of structure, which are shown in tlie three preceding species ; and a further collection of disconnected valves will doubtless enable us to discover additional points of disagreement in specific characters. The three preceding species, with this one, are scarcely regarded as distinct, and are usually found mingled together in collections. This species, and O.ninuata, often suffer distortion from pressure, and on this account are frequently inequilateral, and the sinus of one valve, with the corresponding elevation upon the other, are unduly developed. Fig- 1 a^ Ventral valve of a young specimen. Fig. 1 b. Profile view of the same. Fig. 1 c. Front view of the same. Fig. 1 d. Dorsal valve of another specimen, with a deep sinus. Fig. 1 e. Front view of the same. Fig. 1 / Dorsal valve of an older specimen, showing the gibbous ventral valve projecting beyond the cardinal line. Fig. 1 g. Front view of the same. Fig. 1 h. Dorsal valve of an old individual. Fig 1 i. Front view of the same, showing the deep sinus of the dorsal valve, and the corresponding elevation on the opposite valve. Figs. 1 /i, m. Cardinal views of young and old individuals. Position and locality. In the Blue limestone of Ohio, at Cincinnati and Oxford (Ohio), Maysville (Kenlucky), Madison (Indiana). Several of the species of Orthis here given, so far as our present knowledge extends, are exclusively confined to western localities, and may not be found in New-York. There arc others which will probably be recognized among the imperfect specimens found in the Trenton limestone of New-York, but which are too imperfect for description. All the specimens figured, except those given on the authority of iVIr. Conrad, were found as- sociated with well known Trenton limestone fossils, and have been collected by myself, as well as subsequently furnished l)y several friends in Ohio and elsewhere. TftBNTON LIMESTONE. 131 Genus DELTHYRIS, ok SPIRIFER.* We have but a single species of this genus in our older strata, so far as known at tiie present time ; and this one possesses so many abnormal characters, that M. de Verneuil is inclined to regard it as distinct from the true Spirifer, in having, always, the veniral larger than the dorsal valve. There arc also some other reasons why this species may be regarded as an erratic one, possessing in part the characters of both Orthis and Delthyris. We sliall have observed, in some of (he preceding species of Orthis, a remarkable departure from the general external forms of this genus, and an approach to the Delthyris ; this variation in external form is also accompanied by a difference in the internal characters. The area and foramen being common to both valves, is a character of frequent occurrence in Orthis, but rare in the Delthyris, where the ventral valve of normal species scarcely presents the vestige of an area or foramen. It is very remarkable that the single species known in our older sirata, and apparently the earliest created one both on this continent and in Europe, should present characters common to the Orthis, which is so well characterized, and the species of which arc very numerous in our older rocks. The Delthyris, we shall observe, also, is not one of the earliest developed forms ; for in the first epoch when Brachiopods occur, we find LEPTiENA, Orthis and Atrypa ; while in the epoch of which we are now speaking, we find these three forms largely developed, with a single one assuming the delthyroid type, which, in subsequent periods, becomes so numerous in species. Glancing for a moment at the Brachiopods in their successive appearance upon our globe, we find that Lept^na, Orthis and Atrypa, appear at tiie same period ; and these must be regarded as types in the order of time, and as those to which we should rCally look for our ideas of generic character. In the second period, or the one of which we are now speaking, we find the orthoid type has admitted of some modifications, and that the first delthyroid type possesses some of those characters wliicli are thrown off, and the true normal character assumed in subsequent periods. ^ If we clioose to look a little fartlier, we shall find the lept»noid forms furnisiied with spines on the cardinal margin (the Chonetes, Fischer) ; and, finally, that as the surface * I have preferred to use the term DeHIiyris instead of Spirifcr, though both names have at tlie present time the same application. The genus Spirifer was proposed by Mr. Sowehby, ten years in advance of D.\lma.x's sub- divisions of tlie Brachiopod.-v ; but tlie characters given by the former do not separate that genus from Orl/iis, and not only have specimens of that genus, but also of Atrypa or Tcrebratulu, been confounded under the same term. The spiral appendage within tlie shell, which gives origin to the name, is found likewise in several species ui Mrypa in the pateozoic strata; and this therefore cannot be regarded as a distinguishing character, any more than the deltoid foramen in Delthyris, which is equally common to Orthis Since, however, the application of the two names is now precisely similar, either one may be used without producing confusion ; and I am well satisfied that a subdivision of the genus Spirifer (as now limited in Europe) will be made, when the species, varying so much in external character, shall be more carefully studied. 17* i;J2 PALEONTOLOGY OF NEW-YORK. of these forms becomes entirely spinous, they have assumed other characters essentially different from Lept.€;na, and become the true Productus. In the same manner the Atrypa of the older rocks, having no visible foramen or perforated beak, passes through some other modifications, and gradually assumes the characters of the true Terebratula. At the same time, the deviations from the type of Atrypa give rise to the Genera Pentamerus, Strigocephalus, &c.; while some of these approach the Delthyris, which never departs from its normal character to such a degree as to warrant a generic distinction, according to our present knowledge of these forms. DELTHYRIS BIFORATUS. TcrebratuHtes bifqiatvs. Schlotheim, 1820, Petrefacta, p. 265. Atrypa dorsata? Hisinger. 1S37, Lethaea Suecica, pag. 76, pi. 21, fig. 14. Spiri/er biforatus. F.ichwald, 1S40, .Sil. System in Esthland, p. 144. — — MuRcHisoN & Vehneuil, 184.'), Geol. and Pal. Russia, &c. Vol. li. p. 1.35. Vai'. A. Spirifcr lynx, Eichvv.ild. Var. B. — chiitahiSy Pander. Var. C. — chamu, Eichwald. The synonymy above is cited from the work of Messrs. Murchison and de Verneuil^ on the Geology and Palaeontology of Russia and the Ural Mountains. Under this species^ three principal varieties are designated, while the T. biforatus of Schlotheim is very rare both in Europe and elsewhere. The characters by which that one is distinguished from the other principal varieties, appear to be, according to von Buck, the existence of five plaits in tlie sinus, and the greater propoitional width of the shell. These characters alone are scarcely sufficient to constitute a variety ; for we have specimens willi five plaits in tlie sinus, where the width is not extended ; while we have others with this number of plaits, where the width is extended ; and again we have specimens with a fewer number of plaits in the sinus, where the width is much extended : so that it is scarcely possible to find any constant variety in this respect. The examination of more than one hundred specimens from ditTerent localities has scarcely shown two precisely alike in every particular, except the very young shells, which, both in New-York and in western localities, often present the same essential characters in every respect. We are able to distinguish, in our American specimens, at least an approach to the throe varieties cited ; but there are so many intermediate forms, tliat strict distinctions cannot be drawn. This we should expect, when we notice the fact just stated of the extreme variation in the external characters, so that we can scarcely hope ever to find constant forms in any one of the varieties : neither should this be expected, for a constant variety Would compel us to admit a specific distinction. t .,% .. / TKENTON LIMESTONE; 133 172. 1. Var. A. DELTHYRIS LYNX. Pl. XXXII. D. Figs. 1 a-u. Si. \-v. Terebratula lynx. Eichwald, 1830, Skizze von Podolie, p. 2U'.i. Spirifir lynx. Von Buch, 1s37, Ueber Dclthyiis, p. U. — — Id. ISK), Mem. de la Soc. i;(5ol. de France, Vol. iv. p. 100. — — KicHWALD, l^li), Sil. System in Esthland, p. ll.'i. — — Shkppardi de Ciistclnau, 1S-J3, Terrains siluriens de 1 'Amiriciue du Nord, p. 12, t. 11, f. 1.5. — — MuRCHisoN and Veh.neuii,, ISIT), Gcol. and I'al. Russia and the Ural Mountains, Vol. ii. pag. 130, pi. 3, fii;s. 3 a, S, and 4 a, b. ■ Shell scarcely transverse, varying from seniicUiptical to subquadrate and globose, often nearly as thick as long ; length and width as 5 to 9, or equal ; cardinal line often exceeding the width of the shell, and usually extended into short acute ears, or rounded at the extremities ; area common to both valves, as also the foramen ; ventral valve more gibbous than the dorsal valve ; surface marked with strong angulatcd longitudinal plaits, about three to four of which mark the sinus, and four to five the elevated mesial lobe ; transverse- ly ornamented by concentric or flexuous elevated subiml)ricating lines, which are very obvious on the lower half of the shell, becoming very distinct in front, and, in perfect specimens, continuing nearly to tlie beak. Examined with a magnifier, the surface is seen to be covered with very fine granulations, like those in some specimens of recent Tere- BR.\TUL.a;. It is impossible to assign any definite form or proportions to a shell as variable as this species. The cardinal line, in young shells, usually terminates in small acute ears extending beyond the width of the shell ; while in other cases, and particularly in the older and more gibbous specimens, the cardinal line is less than tjic width of the shell, and its extremities are rounded. There are, somewhat rarely, exceptions to the above observation, where the cardinal line, in old individuals, still extends into small acute ears. The number of plica- tions is very variable also ; but there is usually a relation between the number of those on the sinus and medial lobe, and those on either side. The greater or less number of these plications, however, has no reference to the form of the shell. This species, like many others of the Brachiopod.^, is influenced by local circumstances, and, in its wide geographical distribution, presents varieties of form, or types peculiar to different localities, dependent apparently upon the condition of the ancient ocean bed. In the dark carbonaceous limestones of Nev/-York, it is almost always small ; while in the lighter colored calcareous mud or shale of the West, it reaches a much greater size, and presents a greater variety of form. The eastern type of this species presents the following characters in its different stages of growth and development : In the young shell, there first appears liiree plaits in the sinus of the dorsal valve, with four on the corresponding medial lobe of the ventral valve ; these four becoming two aijout one half or two thirds of the distance from the base to the beak. As the shell grows older, 134 fAL^ONTOLOGY OF NEWiYORK. another plait is developed on one side of the sinus, and a corresponding one on the medial lobe ; but the five thus developed become two before reaching the beak. In the larger specimens of the New- York type (fig. Id), there is a fifth plait developed in the sinus, with six upon the corresponding medial lobe. The outer one on each side unites with the adjoining one about half way to the beak, thus making four plaits on the medial lobe, which finally unite in two before reaching the beak. The additional plaits of the medial lobe are developed laterally by a division of the outer one, which takes place at nearly regular intervals corresponding to the increasing size of the shell. The lateral plications in the sinus likewise disappear towards the beak, not by uniting with the adjoining ones as on the opposite valve, but by gradual diminution till they are lost in the surface of the shell. The plications on each side of the mesial lobe and sinus increase in like manner by the development of additional ones towards the margin of the shell ; and from seven, the number usual in the smallest shells, they increase to ten or eleven, the greatest observed number in any specimen presenting the characters here given ; the increase of lateral ones always keeping pace with the development of additional ones in the sinus and medial lobe. I have observed, in two specimens, a deviation from this rule ; for although they are much larger than any of those before noticed, there are but three plaits in the sinus and four on the mesial lobe ; while the lateral plaits are twelve in one specimen, and thirteen in the other, on either side of the sinus. This curious deviation from the rule before observed, seems due to the non-development of medial plaits, which have been developed upon the sides instead of the sinus ; the total number on each valve being nearly the same as when the medial ones are more numerous. The western types begin in like manner with three plications in the sinus and four on the mesial lobe, while the lateral plications are almost uniformly seven ( sometimes six and rarely five). As the size increases, however, the medial plications do not, as a prevailing character, increase as in the eastern types, but remain still three on the sinus and four on the lobe, till the shells reach to four or five times the dimensions of the largest New-York specimens. At the same time, also, the prevailing number of lateral plications is seven on each side of the sinus or lobe ; and so long as the mesial plications remain three and four, so long the Interal ones are seven. As soon as there is even an appearance of a departure from this number on the mesial lobe and siiuts, and where the rudiment of an additional plait is visible, we then find the lateral plaits to be nine or ten. These changes take place independent of the size of the shell, or of its rotundity ; all variations in the plaits of the siinis being accompanied liy a change in the number of lateral plates. This is illustrated in the figures of nearly equal dimensions, where the specimen fig. 1 a has three plaits in the sinus and four on the mesial lobe, and seven on each side ; while fig. 1 g has a partial development of the fourth ])hiit in the siiuis, and an obscure rudiment of a fifth on the mesial lobe, and at the same time it has ten on each side of the sinus. Even irregularities in tlie development of the mesial plications are followed by irregidarities in the lateral ones. A single specimen Ikis two plimlioiis in the sinus and (liiee on the mesial lobe, and also on one side of llie slope of (he sinus, as well ay on the slope of the nu'si;d lobe, a single TRENTON LIMESTONE. 135 plication, wliicli is intennediate to the mesial or lateral series ; and the lateral plaits, in this case, arc six on one side and seven on the other. In one individual (fig. 1 r), approaching to S. chama, and having but one fully developed plication in the sinus and two on the mesial lobe, the lateral ones are nine and ten. In two other specimens resembling tlie last, where the mesial plates are better developed, the outer ones being still smaller, the lateral plications are eight on each side. In two otlier some- what similar specimens, the lateral plications are six on each side ; while in a single smaller one, there are but five plaits on each side of the middle lobe and sinus. In the six specimens here enumerated, the shell is more distinctly trilobate ; the sinus deeper and more elevated in front, lifting up the mesial lobe higher in this part than it is in (lie centre of the shell, thus contrasting with the prevailing forms before noticed. Tiiese forms constitute a variety, which, though easily traced to the prevailing form, is nevertheless somewhat constant, and worthy of attention, being the nearest approximation to the Var. B. Sp. dcnfatus, which occurs in Russia. It has only been possible to illustrate the characters of this species by a great number of figures, drawn from a selection of specimens, both of New- York and the Western States, which exhibit in the best manner (lie gradations in form, and other characters which this truly protean species presents. Figs. 1 a, b, c, d. A series of specimens, showing the gradations in size, and the increase in number of plications as the shell becomes older. The smaller specimen 1 a has three plaits in the sinus and four on the inesial lobe, with seven on each side, thus : 7 -| 7. In fig. 1 b, there is the partial development of a fourth plication in the sinus, and a fifth on the mesial lobe, though there is no increase in the number of lateral ones. In figs, c and d, there is a full develop- ment of the I medial plications, and 10 lateral ones; the last specimen being about the sine of this type in the New-York rocks. Figs. 1 e and f, are front views of a and d. Fig. 1 g. Profile view of the specimen d. Fig. 1 h. Ventral valve of another form, showing extended beaks. Medial plications i ; lateral ones 1."? on each side. Fig. 1 i. Front view of the same. Figs. 1 Jc, I, m, 0, q, s, u. A series of western specimens, with the mesial and lateral plications (747); showing no tendency to increase of either number, though the size of the shell increases as in the previous series. Figs. I m, q and s, show the cardinal extremities more extended and acute than in the other forms; while the specimens o and u have the cardinal extremities shorter, scarcely equalling the width of the shell. Figs. 1 n, p, r, t, are front views of figs. 1 m, o, q, s and u, respectively. Fig. 1 A, B. Cardinal and profile view of an extremely globose specimen, having the cardinal line much less than the width of the shell, and the extremities rounded. The area is broad, and very well defined. The plications arc 7 f 7. Fig. 1 c. Dorsal valve of a specimen, having the cardinal lino extended beyond the width of tlte shell, and terminating in short acuto ears. 136 PALEONTOLOGY OF NEW-YORK. Fig. 1 D. Front view of the last, showing the plications, which are 10 f 10. Fig. 1 E. Profile view of the same. Fig. 1 F. Cardinal view of another specimen^ with the extrenaities extending beyond the greatest width of the shell below. Fig. 1 o and h. Front view and profile of a specimen similar in form to 1 b, but having the plications 10 i 10. The cardinal line is less than the width of the shell, and the e.xtremities rounded. Fig. 1 I, K. Front view and ventral valve of a cuboidal specimen, showing some irregularity in the development of the plications ; a single one in the sinus and two on the medial lobe being fully developed, with smaller ones on each side, while the lateral plications are six and seven. The following present some deviation from the prevailing forms, and approach to the Var. B. Sp. dcntatus of de Verneuil. The front of the medial lobe, in all of them, is elevated higher than the centre of the same valve ; while in the previous ones, the greatest elevation is in the centre of the shell, the front curving downwards. Fig. 1 L, M, N. Ventral, dorsal, and profile view of a small specimen, with the plications arranged thus : 5 f 5. Fig. 1 o, p, Q. Ventral, front, and profile view, having the same form and proportions as the last, but having an additional plication upon each side. Fig. 1 R, s, T, u. Ventral valve, front, cardinal, and profile views of the same specimen, which is re- markably extended on the hinge line. This specimen has a single fully developed plication in the sinus, and two on the mesial lobe, with the rudiment of another on each side of the sinus and of the medial lobe, while the lateral plications are ten on each side. Position and locality. This species occurs in numerous and widely separated localities of the Trenton limestone, being confined to the rocks of this period in the United States, and unknown in New-York above the Utica slate, though this line of demarcation cannot be recognized at the West. Within the State of New- York, it is found at Middleville, Trenton Falls, Herkimer, Jacksonburgh, and other localities in the Mohawk valley. It is also found at Turin, Watcrlowii, and other places towards Lake Ontario, and is likewise known at several places in the Champlain valley. It is found in great numbers at Maysville and Frankfort ( Kentucky) , near Nashville (Tennessee), at Cincinnati and Oxford (Ohio), at Madison (Indiana) , at Mineral Point ( Wisconsin), and on the northwest shore of Lake Michigan and towards Green Bay. It likewise occurs at several localities in Canada East and West, showing a geographical distribution equal to the extent of (he lower silurian strata of our country. It appears likewise in the lower silurian strata of Russia and the north of Europe, having there, as elsewhere, a wide geographical distribution. (Slate Collectioti.) TRENTON LIMESTONE. 137 ATRYI'yE OF THE TllENTON LIMESTONE. Several species of this gemis arc widely clifTiised in tlie Trenton limestone, tliong-h none of tlicni are so abundant in New-York as the Lkptjena and Ortiiis. The species most common in this Stale are known to occur in Ohio, Indiana and Kentucky, in the same formation, and ranging throughout a much greater thickness of strata. While several species of tiie LEPTiENA, and the Orthis testudinaria., occur at nearly every localitj' of tlic Trenton limestone in New-York, the AtrypjE are for the most part restricted, and the dilTerent species can only be sought successfully at dillerent localities. It should be observed, however, that many of our most prolific localities of fossils have been but partially explored, and therefore we cannot speak with certainty of all ; still it is believed that the paleonto- logist will find the above remarks generally true in relation to the distribution of species. 173. 6. ATRYPA EXTANS. Pl. XXXIII. Figs. 1 a, b. Atrypa extant!, Conr.vd in MS. Emmons, Geol. Report, 1842, pag. 3'J5, fig. 6. Compare Atrypa subtobata, Portlock, Geol. Tyrone, &c. 1S43, pag. 567, pi. 3S, fig. 2 b and k. — undata. Sowerby, Sil. System, 1S39, pag. 637, pi, 21, fig. 2. General figure somewhat irregularly globose, or subrhomboidal and gibbous, with the front produced ; length and breadth nearly equal, measuring the projection of the ventral valve; cardinal line remarkably extended, which is very perceptible in fig. li; beaks very small ; dorsal valve transversely oval, with a broad, deejj, not angular mesial sinus, defined by subangular margins ; ventral vulve with a prominent rounded mesial elevation, well defined at the margins by a shallow groove ; front produced, and but little elevated by the corresponding sinus ; surface marked by concentric somewhat undulating filiform lines, and less distinct longitudinal stria;. Length and breadth varying from f to | of an inch. This shell is somewhat common at one or two localities about Watertown in Jeflerson county, in a grey subcrystalline limestone, associated with Trochus Icnticularis, Orthis pectinella, Sfc. It is remarkable for the extended cardinal line, wliicli is more conspicuous in the ventral valve ; as also the profound mesial depression and elevation, neither of which are angular. The concentric lines are not imbricated, but simple elevated stria, more prominent than the fine longitudinal strife that usually appear towaids the margin. Fig. 1 a. Dorsal valve, b. Ventral valve. Position and locality. Watertown, Jefferson county ; Lowville, and Sugar River near Boonville in Lewis county, in the higher portions of the Trenton limestone. (State Collection.) [ Paljjontologv.] 18 138 PALiEONTOLOGY OF NEW-YOKK, 174. 7. ATRYPA NUCLEUS. Pl. XXXUI. Figs. 2 a, b, e. Cpmpare A. cxtans nf supra. General form subangiilarly globose ; lengtii and breadth about equal ; cardinal line regularly curved ; beaks small, close pressed, that of the dorsal valve incurving over the other ; margins of the valves uniting very closely and neatly ; mesial sinus broad, flat, extending about two thirds the length of the shell, and produced into a linguiform extension, which is much elevated in front; mesial elevation prominent, rounded, extending about two thirds of the distance to the beak, where it is lost in the general convexity of the shell ; surface of both valves crossed by filiform concentric lines, which are undulated in crossing the mesial sinus and elevation ; no visible longitudinal striae. This shell resembles the last one very closely, the principal difference being the extended cardinal line in the former ; the mesial sinus in the latter is flat and more elevated in front, while the mesial elevation on the opposite valve is less extant, rising more gradually from the surface of the shell, and not so distinctly margined by a shallow groove, nor produced in front. A comparison of a larger number of specimens may prove the existence of a gradation in the cliaracters, here noticed as distinctive. Fig. 1 a. Ventral valve, b. Dorsal valve. «. Profile view. Position and locality. MiddleviUe, Herkimer county, in the central portions of the Trenton limestone, associated with Conularia. 175. S. ATRYPA CUSPIDATAt (n.5j9.). Pl. XXXIII.* Figs. 1 a, b, c, d, e,f, g, h. Obtusely pyramidal or somewhat obcordate ; width greater than the length ; dorsal valve smaller than the ventral, convex at the sides, with a broad subangular depression which commences near the beak, and becomes broader, deeper and more angular, elevating the front of the shell into a cuspidate extension ; lower half of the sinus marked by a distinct narrow groove in the centre ; ventral valve very gibbous, with a broad mesial lobe which continues nearly to the beak, and extends in front scarcely so far as the line of the shell on each side ; beaks nearly equal, that of the dorsal valve incurved over the ventral valve, the latter being much more gibbous below the beak ; margins of the shell sharp ; surface ornamented with fine elevated concentric striae, which are imbricated towards the margin. The lower half of the shell, particularly on the ventral valve and sinus of the dorsal valve, is marked by numerous sharp radii, which gradually disapj)ear above. This species bears a close resemblance to Jltrypa exlans ; Init the specimens of that shell which I have been able to see, are all of separated valves, and differ from this one in Uie t PL xxxiii.* is a sriiiplementary plate. TRENTON LIMESTONE. 139 Straight hinge line, and pioihiced front of tlie medial lobe, as far as can be ascertained, though it has some obscure longitudinal strife. The shell is frequently nuich expanded laterally, and compressed towards the edges ; the beaks arc almost equally elevated, that of the ventral valve being more gibbous than the other. There is some variation in the sinus of the dorsal valve, which, in some specimens, is more produced and acute in front than in others, while the medial lobe often becomes angular. This species is apparently quite distinct from A. nucleus, which has a flat sinus in the dorsal valve, rounded at its extremity, and the surface of the shell presents no longitudinal striae. Fig. I a. Ventral valve of a perfect specimen, b. Front view of the same. Fig. 1 c. Dorsal valve, d. Profile view. Fig. 1 e. Front view of a specimen, where the sinus is narrower and more angular than in the preceding. Fig. 1 / Profile view of the same. Fig. 1 g. Dorsal valve of a specimen, which is more extended laterally. Fig. 1 h. Front view of the same specimen. Position and locality. This species is known to me only as occurring in the central part of the Trenton limestone, at Lowville, Lewis county. testate Collection.) 176. 9. ATRYPA BISULCATA. Pl. XXXIII. Figs. 3 a, b, c, d, e. Orthis bisulcata. Emmons, Geol. Report, 18-42, p. 395, fig. 4 a, b. Small, ovoid ; dorsal valve with a well defined, narrow, mesial sinus, which continues about half way to the beak, and from there the centre becomes much elevated ; beak of the dorsal valve strongly incurved over that of the opposite valve ; ventral valve depressed- convex, prominent on the umbo, beak very small and abruptly incurved ; front with two short well defined furrows, ending in two plications, whicli close on each side of the projecting plait formed by tlie extension of the mesial groove of tlie dorsal valve. This peculiar little shell has no analogue in any of the lower strata, though there are one or two approaching to it in form in the higher rocks. Its neat ovoid form, smooth or concentrically striated surface, with the two small plaits and grooves in one valve and one in the other, are marks to be sought for in identifying the species. It is extremely rare, and has been found only in one or two localities. Fig. 3 a. Dorsal valve, b. Ventral valve, c. Cardinal view. e. Front view. d. Enlarged profile view. Position and locality. Adams, Jefferson county, in shaly Trenton limestone, associated with MuRCHisoNi.\ and Pleurotomaria, and in a situation where few Brachiopods occur. (State ColUcHon.) 18" 140 PALJEONTOLOGY OF NEW-YORK. 177. 10. ATRYPA DEFLECTA { 7!. «;>.). Pl. XXXIII. Figs. 4 a, b. Sub-planoconvex, with the margins compressed, and deflected towards the front ; length and breadth about equal ; cardinal line somewhat extended, curved ; dorsal valve with a prominent ridge along the middle; beak extended, prominent, incurved; ventral valve depressed-convex, with a mesial sinus ; surface with about 20 small regular radiating striae, which are rarely divided towards the margin. A few specimens only of this shell have been found ; in these, the form is constant, as represented in the figure ; but the markings and general aspect approximate it to the next species. Fig. 4 a. View of dorsal valve, b. Front view, showing the form of the two valves. Position and locality. Near Martinsburgh, Lewis county, in the central part of the Trenton limestone. 178. 11. ATRYPA RECURVIROSTRA (n. 5/j.). Pl. XXXIII. Figs. 5 a, b, c, d. Elliptical, somewhat ovoid, very symmetrical ; breadth one fourth of an inch, length a little greater ; dorsal valve with the middle elevated, regularly convex on the sides, the beak extended and gracefully incurved over the beak of the ventral valve, which is re- gularly convex, with a slight longitudinal depression ; surface of each valve marked by about 24 regular simple longitudinal stria-, which continue entirely to the beak. The preceding species approximates to this one in general form and character of stria ; but the sides are more expanded, and the shell has a distinct mesial sinus and elevation. These characters usually increase with the age of a shell ; and since the form of the one under consideration is very constant in a large number of specimens, which are of nearly uniform size, and smaller than the one figured, we may presume that it is a distinct species. It will be readily recognizetl by its rotund synnuetrical form, which is more elongated, and more finely and evenly striated than any other species in the rock, except the preceding one. Fig. 5 a. Dorsal valve. Fig. 5 b. Profile view. Fig. 5 c. Cardinal view, showing tlie incurved beak of the dorsal valve. Fig. 5 d. Ventral valve separated from the dorsal. This valve is nearly circular, the beak being scarcely extended beyond the cardinal margin. Position and localiiij. This shell occurs in considerable numbers in a compact greyish blue l)cd of limestone near the centre of the Trenton limestone, near Martinsburgh, Lewis county. It has also been seen at Lowville and at Middlevillc. (•*'''"''' Collection.) TRENTON LIMESTONE. . ^ ■ 141 179. 12. ATRYPA EXIGUA (?(. ^;;.). Pl. XXXIII. Figs. G a, b, c, d. A Plano-convex; length and breadth about equal; cardinal line considerably extended ; dorsal valve elevated in a ridge along the middle, depressed at the sides, and slightly inllectcd towards the cardinal extremities ; beak small, straight, much extended beyond the cardinal line ; ventral valve considerably shorter than the dorsal, depressed-convex, witJi a broad depression along the centre, reaching half way from the base to the beak ; beak small, and close pressed into the foramen beneath the ]>vi\k of the opposite valve ; surface scarcely marked with line concentric lines, and a few indistinct longitudinal rays near the margin. ' . In the largest specimen which I have seen, there are evidences, under a magnifier, of small radii commencing below the centre of the valve. Since, however, they are not perceptible to the naked eye, they are of minor importance, unless it should be found that this is the young of a species which changes with growth. The specimens yet seen, how- ever, are minute, and it may properly be doubted whether the species attains a size beyond the largest figures given. The valves are often close pressed, and detlccted at the margin. It bears considerable resemblance to a small species occurring in the.Schoharic grit; but that one is readily distinguished by the absence of any depression in the ventral valve, which is a rare feature among (he Atryp^, and proliably indicates a departure from J,lie true normal character of the genus. Fig. G a. Ventml valve : the depression is proportionally too narrow in the figure. Fig. 6 b. Dorsal valve of the same. Fig. 6 c. Cardinal view, showing the acute slightly incurved beak. Fig. 6 d. Two figures of the dorsal valve of a small and large individual, the form and extension of the acute beak being well represented. . - Position and locality. In the central part of the Trenton limestone at Lowville, and near Martinsburgh, Lewis county. {Stait Cuiiectwn.) ' - 180. 13. ATRYPA MODESTA. Pl. XXXIII. Fig. 13. Producta modfstn. S.tv, Collection of the Acad. Nat. Sciences, Philadelphia, Suborbicnlar or plano-convex, with the beak extended ; width a little greater than the length ; cardinal line distinctly marked and somewhat extended ; dorsal valve convex, with an elevated ridge along the centre, occupied by four plaits which are stronger than the others ; beak prominent, incurved and perforated, the perforation extending below the beak and occupying a portion of the area ; ventral valve depressed-convex, broadly oval 142 PALEONTOLOGY OF NEW-YORK. or nearly circular, with a broad but ill defined sinus along the middle, the central plication stronger than the others, with a smaller one on each side ; each valve with about 18 simple rounded plications ; surface obscurely punctate. This neat and beautiful little species well merits the name bestowed upon it by Mr. Say, which I am happy to preserve. It is a rare species in New- York, while it is abundant in Ohio, Indiana and Kentucky. It is, in a large number of specimens examined, very con- stant in the characters given above. The central elevated portion consists of four stronger plications, which appear to be in two pairs, from being separated in the middle by a deeper and wider groove, while the groove between each pair is narrower than between the other plaits of the shell. These characters, with the stronger plication in the centre of the ventral valve, are constant, and apparently reliable in distinguishing the shell. The mesial sinus on the ventral valve, which is scarcely conspicuous in young shells, becomes deeper and more strongly marked in older ones, and produces a strong depression in the front of the shell. Fig. 15. The two upper figures are of the dorsal and ventral valve of a specimen above the common size. The lower figure is of a small specimen, having the same characters. Position and locality. I have seen this species in New-York only from the Utica slate, or upper shaly part of the Trenton limestone, at Turin, Lewis county. It is quite abundant at numerous western localities, particularly Oxford and Cincinnati (Ohio), Madison (Indiana), Frankfort and Maysville ( Kentucky) . This species, with the three preceding ones, form a group, presenting characters which may require a separation from the true AtryPjE. These characters consist in the elevation of the dorsal valve along the centre, with a depression or sinus xm the ventral valve, being the reverse of the usual arrangement. The beak is incurved, with a perforation at the apex, which occupies, also, a part or all of the deltidial area, being usually narrow and long. Mr. Conrad, some time since, projjosed the name Ste7iocisma for some specimens of the group of ATRYP.a; or Terebratulje, which he subsequently abandoned. Should the charac- ters here noticed be found persistent, and accomjjanied by the narrow foramen, I propose to restore the name first indicated by Mr. Conrad for the genus. 181. 14. ATRYPA CIRCULUS (7!. ^/).). Pl. XXXIII. Figs. 7 a, b, c. Depressed orbicular ; valves equally and uniformly convex ; margins close pressed, with scarcely a conspicuous undulation in front ; beaks equally prominent, one slightly larger, approximate ; surface marked by fine concentric lines, and obsolete longitudinal stria-, which arc only visible by the aid of a magnifier. TRENTON LIMESTONE. 143 This shell appears siiiTiricntly distinct from any other species in tliis rock, lo merit a separation. Its circular I'oriu, and equally convex valves with niarj^ins almost imiform, render it diflicult to imagine a gradation to the succeeding species. It must be confessed, liow^ever, that it approaches in some degree to the young of fig. 10 ; thotigh in fig. 10 d, a specimen of equal size, the plications are very distinct, while, in this species, they are not visible. Fig. 7 a. Dorsal valve, b. Cardinal view. c. Profile view. Position and locality. Tliis species occurs in the compact black limestone, with others of the genus, at Middleville, Herkimer county. 182. 15. ATRYPA AMBIGUA (7(. $/).). Pl. XXXIII. Figs. S a, 6, c, &, 9 a, A. Subrhomboidal, trilobate ; length and breadth about equal ; cardinal line somewhat extended in a regular curve ; beaks subequal, approximate ; dorsal valve convex near the beak, depressed towards the sides, with a deep, somewhat flat mesial sinus, which is extended and considerably elevated in front ; ventral valve with a prominent elevated mesial fold along the middle, which disappears before reaching the beak ; surface crossed by fine concentric lines, with a few obscure or incipient plications in the mesial fold and sinus ; sides of the shell rarely plicated. Figs. 8 a and b, represent this shell in its usual form, with a simple trilobate aspect, and free from plications. Fig. 8 c. Front view in outline, showing two incipient plications in the sinus. Fig. 9. Four valves are represented precisely as they occur on the surface of a slab of limestone. In two of these figures, a ventral and dorsal valve, the shell is free from plications either on the mesial fold or on the sides ; while in a ( a dorsal valve), both the mesial sinus and the sides of the shell are very distinctly plicated, and the contiguous figure of a ventral valve is subtriplicate in the mesial fold only. ' , - , This great deviation in external markings suggests the inquiry whether this shell may be a variety of some other species. The simple unplicated form approaches to Jltrypa nucleus ; but the form of the shell, the mesial sinus, and its extension in front, are all too different to allow of our confounding them. On the other hand, the plicated forms bear some resemblance to fig. 10, from which this differs in the greater length of the sinus, which extends nearly lo the beak, while in that one it is short, terminating abruptly, and extending little more than half way to the beak ; and in young shells, where the incipient plications are observed, the sinus is barely perceptible. Position and locality. In the lower part of the Trenton limestone at Middleville. A* 144 PALEONTOLOGY OF NEW-YORK. 1S3. 16. ATRYPA HEMIPLICATA ( n. sp.). Pi.. XXXIII. Figs. 10 a, b, e, d, e,f. Subglobose, pentagonal, wider tlian long-, thickness often equal to the length ; cardinal line distinct, short, with ( in some specimens) the appearance of a small area on the dorsal valve; dorsal valve depressed -convex, with an abrupt, broad, not deep sinus, which commences nearly half way from the beak to the base, the beak very small and closely incurved ; ventral valve very convex, becoming gibbous, with a broad mesial elevation commencing one third of the distance from beak to base, more gibbous towards the beak; sinus marked by two or three strong plications, with three or four upon the mesial lobe and two or tliree upon each side, all of which reach from one third to one half the distance from the base to the beak of the shell, leaving the upper lialf entirely free from these markings ; entire surface ornamented by fine, concentric, filiform, subimbricating lines, which are more conspicuous towards the base of the shell, and beautifully undulated in crossing the plications. Tliis peculiar and beautiful species is rarely found in western localities, but is never- theless extensively distributed in New- York. It is readily distinguished by its usually rotund figure, and the short prominent plications on the lower half of the shell, while it is smooth above, or only marked by the tine concentric lines. The sinus at the base usually occupies about one fifth of the circumference of the shell, which, with the basal and cardinal slopes, gives it a pentagonal appearance. In many specimens, collected from the crystalline limestone, I have been able to observe only the plications on the mesial portion ; while in the softer or shaly limestone, the lateral ones have all the distinctness of those presented in the figures. Fig. 10 a. Dorsal valve of a specimen of the ordinary size. Fig. 10 A. Profile view of the same. Fig. 10 c. Front view of the same, dorsal valve below, showing three plications in the sinus and four on the mesial lobe. Fig. 10 e. Ventral valve of a large specimen, with only three plications on the medial lobe. Fig. 1 0 /. Front view of the same, showing the extreme gibbosity of the ventral valve. Fig. 10 d. Dorsal valve and front view of a young specimen, having but a single plication in the sinus, which is only rudimentary, and two on the medial lobe. The two valves in this shell are almost equally convex, the beak of the dorsal valve curving very neatly over that of the ventral valve. Position and locality. In the tiiin shaly layers near the base of the Trenton limestone at Middleville, and in the higher crystalline portions of tlie same rock at Watertown, Turin, and other localities in the northwestern part of New-York. (Slate Collection.) TRENTOiV LIMESTONE. 145 181. 17. ATRYPA {Species undetermined). Pl. XXXIII. Figs. U a,b,c. Somewhat circular or suhorhiciilar ; dorsal valve flat or depressed at the sides, depressed in the centre, with a broad curving sinus which is little elevated in front; beak small, scarcely incurved ; ventral valve very convex, somewhat gibbous, with a broad medial elevation and sloping sides ; beak small, incurved within that of" the dorsal valve ; surface marked by filiform concentric lines, without longitudinal plications. I have been inclined to regard this species as the young of Jl. extans or Jl. cuspidata, but there are some objections to thus referring it. The sinus is broad and shallow, not distinctly margined, and is broadly rounded in front, as is also tlie mesial lobe of the opposite valve. The dorsal valve is (latter, and the beak appears to be less incurved than in either of the species named. It differs from the last species in the inetpiality of the valves, and the absence of plications either upon the sinus or sides of the shell. Fig. 11 a, b. Ventral and dorsal valves of this species. Fig. lie. Front view of the same ; the dorsal valve below. Fisr. 11 d. Profile view of the same. Position and locality. In the central portions of the Trenton limestone at Middleville, Herkimer county. 185. 18. ATRYPA SUBTRIGONALIS ( n. sp.). Pl. XXXIII. Figs. !•,> n, b, <•. General form subtriangular, with a rounded base ; length and greatest breadtli equal ; cardinal line short, well defined, with the appearance of a small triangular foramen under the beak of the dorsal valve ; cardinal slopes long, straight ; basal margin regularly curved, with a slight cmargination at the sinus ; valves almost equally convex ; dorsal valve extended beyond the ventral, beak scarcely incurved ; surface marked by about 20 rounded radii, three of which are in the mesial sinus and four on the mesial elevation, ornamented by elevated concentric lines which are undulated in crossing the plications. A distinguishing character of this shell is its triangular form, with extended small beak ; the mesial sinus and elevation are narrow, and continue only about two thirds of the distance from base to beak. This species is rare, occurring only in one or two localities. It may perhaps be regarded as a variety oi Jltrypa increhesceiis ; but it differs considerably in form, and has a larger number of plications, as will be seen on comparison ; even the oldest individuals of fig. 13 rarely having more than fifteen plaits, though specimens of twice the size of this are often found. [ PaLjEontolooy.] 19 146 PALEONTOLOGY OF NEW^YORK. Fi"' 12 a. View of the ventral valve, with the beak of the dorsal valve projecting above. Fig- 12 b. Profile view of the same. Fig. 12 c. Front, with the dorsal valve below. Position and locality. In the upper part of the Trenton limestone at Turin, Lewis county. {^Collection of Mr. Alson Clarke, of Turin, on whose authority this species is quoted from the Trenton limestone.) 186. 19. ATRYPA INCREBESCENS {»..?;).). Pl. XXXIII. Figs. 1.3 a-y. rompare Terchrattda plicatclla, D.^lman {Anomia plicatella, LiNNi5--.us), 18-37, Vet. Acad. Handl. pag. .56, pi. 6, fig. 2. — — HisiNGER, 1837, Lethsea Suecica, pag. 80, pi. 23, fig. 4 a, b, c. Spheroidal, gibbous, ovoid or subtriangular ; length and lireadth nearly the same, in older specimens very variable ; dorsal valve with a broad, more or less deep sinus, which, in older specimens, reaches nearly to the beak, and is marked by three or four plications, which finally become much elevated in front, producing a deep emargination in the opposite valve ; beak of the dorsal valve small, acute, and, in young specimens, slightly incurved, with a perforation beneath the apex. In older shells, the beak becomes strongly incurved, and closely pressed against the opposite valve. Ventral valve regularly convex in young shells, with a slight elevation in front ; as the shell advances in age, the medial lobe is developed, and, in old specimens, reaches nearly to the beak. Surface of the shell marked by twelve to sixteen plications, three or four of which are in the sinus and four or five on the medial lobe, the plaits never subdivided ; transversely marked by elevated flexuous imbricating lines, which, in young and well preserved specimens, continue entirely to the beak. This species is an associate of Delthyris lynx, and is equally variable with that shell. It has been referred to Terebratula tripartita ( Sowekby, Sil. System, Vol. ii. fig. 15), a Caradoc species ; but I regard our shell as quite distinct from that one. The smaller varieties approach more nearly to T. pusilla (Sovverbv, Sil. System, pag. 641, pi. 21, fig. 18). If described at all, in any foreign work within my reach, the species does not present the remarkable variation in form, on the other side of the Atlantic, that it does in this country. This species, like its constant associate Delthyris lynx, is much more developed in the West than in New-York, where all the specimens I have seen are small, and rarely approach the globose forms of western localities. The most common forms in New- York are those represented in figs. 13 a, h, c and d. In fig. 12 a, b, ventral valve and front view, the specimen has 16 or 17 distinct plications, four of which are elevated upon the mesial lobe. The form of the shell is somewhat triangular, the mesial TRENTON LIMESTONE. 147 elevation scarcely distinct, and the sinus short, extending less than half way to the beak ; the plaits arc more angular, from a partial exfoliation of the shell. Fig. 13 c, d Ventral valve and profile view. The specimen more rotund, and the surface marked by fifteen plications ; the medial lobe is more elevated, and the sinus extends nearly to the beak. The fiexuous imbricating strice, in both these specimens, are nearly destroyed from ex- foliation of the shell. Fig. 13 e,f. Ventral valve and profile of a more gibbous form, the valve being nearly circular or broadly oval, and the beak less exsert than in the last. The number of plaits is 16, and they are distinctly marked by the concentric fiexuous lines. ^'S- '3 oi ^! *• Front, profile and ventral valve of a larger and more rotund specimen, having a deeper and more strongly defined sinus and medial lobe, and the beak of the dorsal valve closely curved over the ventral valve. The surface is marked by 16 plications, which, as in the preceding specimens, are defined entirely to the beak. This specimen is the maximum size to which those of New- York attain ; but in the western localities, we are able to trace the species from its smaller forms through all the grades here presented, beyond which it assumes the more globose appearance shown in some of the following figures. Fig. 13 L A small specimen of the western type, corresponding very nearly with 13 a in size and form. Fig. 13 /j m, n, o. Ventral valves and front views of two larger individuals, showing a gradation in size. Every possible intermediate form between 13 k and the following specimen may be found in almost every locality. Fig. 13 ;>, r, s. Ventral valve, profile and front view of a larger specimen, varying but little in its pro- portions from the preceding ones. The sinus is deeper and more strongly defined, and the ventral valve more ernarginate in front, from the extension of this portion of the dorsal valve. Fig. 13 t, n. Profile and front view of a more gibbous specimen. Fig. 13 w. Profile view of a very gibbous specimen, which has become nearly globose, the thickness equalling the length of the shell. Fig. 13 X. Front view of the same, showing the sinus of the dorsal valve much extended and elevated in front, fillmg the deep emargination of the opposite valve. Fig. 13 y. Cardinal view, showing ihe sinus and medial elevation, extending nearly to the beaks of the shell. Specimens are frequently seen, where the gibbosity of the shell is much more extreme than in this one, the thickness being one third greater than the height of the shell. " A series of this species, and of Delthyris lynx, showing all the variations in form and size, constitute a very interesting collection for the study of those changes in species of the Brachiopoda, induced by age and local influences. Position and locality. This species is found in New-York, in the central and higher part of the Trenton limestone, very rarely in the lower part. It is found in all western localities of this rock, ranging througli several hundred feet in thickness. It occurs at JMiddlevillc, Trenton Falls, Herkimer, Turin, Watcrtown and other places in New-York. It is abundant at Cincinnati and Oxford (Ohio), iMadison (Indiana), iMaysville and Frankfort (Ky.), and numerous other places. (State Collection.) 19* 148 PALiEONTOLOGY OF NEW-YORK. 187. 20. ATRYPA DENTATA {n.sp.). Pl. XXXIII. Figs. 14 a, b, e. Pyramidal, subtriangular ; breadth somewhat greater than the length ; cardinal line short ; margins of the shell sloping abruptly downwards ; surface marked by about eight or nine strong and deep plications, two of which are much elevated on the mesial fold of the ventral valve ; dorsal valve with the sinus broad, deep and angular, with a single plication in the centre, extremely elevated in front j plications crossed by zigzag or ad- vancing and retreating filiform lines ; beak of the dorsal valve small, acute, incurved, with no visible perforation. This remarkable litlle shell is distinguished by its deep mesial sinus and strong plications, particularly the central ones. The plaits are simple, reaching entirely to the beak, and enlarging rapidly below. An analogous species, the ^. duplicata, with fewer plications, occurs in the Chemung group. Fig. 14 a. Dorsal valve. Fig. 14 A. Front view of the same; the dorsal valve below. Fig. 14 c. Profile view. Position and locality. In the higher part of the Trenton limestone at Turin, Lewis county. {VoUrction of Mr. Alson Clauke, on whose authority I have placed it among the Trenton species, not having mysf If collected the same from the rock.) 188. 21. ATRYPA SORDIDA (7(.sp.). Pl. XXXIII. Fig. 1(5. Circular : valves equally convex ; beak of the dorsal valve extended beyond the other ; surface marked by small simple radiating strife, which are crossed by elevated lines, giving a rugose appearance ; no mesial sinus or elevation. This is pfobably a young shell, having the sharp striae more distant than the spaces between them. The precise locality of this specimen is uncertain, but, from its association, there can be no doubt of its position being that of the Trenlon limestone. TEENTON LIMESTONE. 149 I ACEPHALA OF THE TRENTON LIMESTONE. » Plates XXXIV., XXXV. & XXXVI. In the fossils of this class, wc find a much g^roater difliculty in the determination of genera and species, than in the Brachiopoda, where the external characters alone are often sufficient for this purpose. The Acephal.4, also, are usually less perfectly preserved, and separate from the rock with greater difficulty, rarely presenting us with any of those characters on which generic distinctions in such shells are commonly founded. In far the greater number of instances they occur as separated valves imbedded in the stone, and in parts of the rock of such a nature that the shell is partially or entirely exfoliated, obliterating even the means of identifying them by this slender aid. The form of the fossil, therefore, is generally the principal or only means of its identification ; and every palaionlologist knows how liable this is to variation, from pressure, and other causes of which we can have but a slight knowledge. It will not be surprising, therefore, that differences of opinion may exist as to the propriety of the reference of many of these species to recent genera, or to genera constituted to receive analogous fossil species of a later epoch, which have been studied with better advantages. Notwithstanding the general paucity of species of this order, I am able to present a much larger nuailjer than have ever before been known from the Lower Silurian period, where they have been regarded as very rare. Among these there are two or three forms which present characters requiring a generic designation, and wliich appear to me not only tiius distinct, but equally distinct from analogous forms in the later deposits. Acting therefore upon the conviction that more good can be accomplished by attempting to discriminate, than to risk confounding with what is really unlike, I have attempted to point out characters which maj' serve at least to distinguish several fossils now generally referred to recent genera, and from which all our knowledge, as well as analogy, would teach us to separate them. The Genus Cypricardia has heretofore been the receptacle of a large number of species widely dill'ering from each other, and few, if any, of which probably belong to the genus. The name of Nucula has also been appended to shells, having few or none of the essential characters of that genus. Avicula, in like manner, has been the name applied to many shells possessing a remote analogy to some forms of that genus ; and Inoceramus, a genus of the Oolitic and Cretaceous periods, has received both Silurian and Carboniferous species. It is true, as just observed, that in many instances it is almost impossible to ascertain with certainty the essential generic characters of these sliells ; but in such cases we should study with more care the external form, and the structure of the shell, which may enable us to arrange the fossil species in natural groups. 150 PALEONTOLOGY OF NEW-TORK. 189. 1. NUCULA LEV ATA ( n. sp.). Pl. XXXIV. Fig3. 1 a-i. Compare JVucula Itpvis, Sowerby in Sil. System, pag. 335, pl. 22, fig. 1. Somewhat obliquely ovate or subrhomboidal, gibbous ; anterior extremity broad, rounded ; posterior side narrower and somewhat obliquely truncated ; umbones usually about one third of the length from the anterior extremity, elevated and incurved ; cardinal line slightly curved ; crenulations extending nearly twice as far on the posterior as on the anterior side ; surface obscurely marked with concentric lines ; muscular impressions visible near the anterior and posterior extremities. This little shell presents considerable variation in form, even in the same locality, becoming greatly increased in height over the prevailing form. It often becomes almost cylindrical from compression vertically ; and again, from lateral pressure, the umbones are much elevated, and the shell broader than the natural form. This is apparently identical with the species occurring in several western localities ; though in these situations it rarely or never attains the great elevation of the innbones, or general gibbosity of the shell, which the eastern forms present. Notwithstanding this prevailing difference, I am unable to find any characters indicating a specific distinction, and therefore arrange them both under the same name. Fig 1 a, b. Left valve and posterior view of a specimen of the prevailing form in New- York. The muscular impressions t t are distinctly visible. Fig. I c, d. Similar views of a larger shell, slightly varying in its proportions. Fig. 1 e Left valve of a very gibbous specimen, in which the posterior side is less extended. Fig. 1 / A specimen less elevated, and approaching the western forms. Fig. 1 g. Cast of a western specimen, showing more distinctly the muscular impressions f t- Fig. 1 k. Cardinal view of the same, sho%ving the crenulations of the hinge, and the same enlarged. Fig. 1 i. A smaller specimen of the same, with the shell showing faint concentric lines. This is the prevailing form of the western specimens, while 1 ^ is intermediate to this and the common New- York forms. Position and locality. This shell occurs in New-York, in the central portions of the Trenton limestone, at Middleville, Jacksonburgh, Trenton Falls, and other places. The western specimens figured are from Mineral Point ( Wisconsin) , whence they were sent with other fossils peculiar to the Trenton limestone. {State Collection.) ' TRENTON LIMESTONE. 151 190. 2. NUCULA POSTSTRIATA. Tl. XXXIV. Figs. 2 o, 6. % t A'ucuUtes poststriata. Emmons, Geol. Report, 1&4'2, pag. 399, fig. 4. Oblong-, somewhat quadrangular, compressed ; extremities of nearly equal widtii ; anterior extremity rounded, posterior one obliquely truncated ; umbones compressed, sharp, with an angular elevation extending obliquely to the posterior basal margin ; posterior slope strongly striated with diverging elevated lines ; remainder of the shell apparently smooth. I have referred this specimen, with some hesitation, to the Genus Nucula, having seen no evidence of crenulations on (he hinge line, and the strong striae upon the posterior slope are characters not usual in species of this genus. The species under consideration is rare in the Trenton limestone, and has heretofore been regarded as belonging to the Hudson-river group, where it is more frequently seen, and where it attains a larger size ; but since I have adopted the invariable rule of giving the species where it first appears, this one is presented here. Fig. 2 a. Right valve of this species, b. Cardinal view of the same specimen. Position and locality. In the compact part of the Trenton limestone, associated with several other species of shells peculiar to the rock. Carlisle, Pa. Genus TELLING MYA. [ From Tellina and Mya, from the form of the shell ) Character. Equivalve, inequilateral, somewhat compressed below, but becoming gibbous at the umbones ; umbones not angular ; outline of the shell curved, without angular ridges ; shell thin, closely laminated ; hinge without visible teeth or crenulations ; muscular impressions two in each valve, near the dorsal margin ; often apparently gaping at the posterior extremity. T. nasuta. This is one of several fossil shells of the Acephalous Mollusca, in the Trenton limestone, which cannot be satisfactorily referred to any of the existing or fossil genera with which I am acquainted. It is with great diffidence, however, that I propose a generic designation for it ; being willing to avoid, if possible, the multiplication of names, where the continuance of previous ones, or the reference to recent genera, will not produce confusion. I am well aware of the difficulty, not to sny impossibility, of properly characterizing a genus, where the specimens are in the condition of these ancient fossils ; and, therefore, general external form, and the structure of the shell, must be allowed some weight. In the present instance, the form of the shell, and some other characters in the typical species, are so widely different that they cannot fail to arrest attention. 152 PALAEONTOLOGY OF NEW-YOllK. 191. 1. TELLINOMYA NASUTA (n. 5;;.)- Pl. XXXIV. Figs. 3 a, b, c. Transversely elongated, inequilateral ; anterior extremity rounded ; posterior extremity greatly extended into a kind of beak, which is narrowed and compressed, contracted on the base by a shallow sinus ; umbones prominent, rounded ; shell thin ; surface marked by fine concentric lines. Tlie muscular impressions are strongly marked upon the cast, and the umbones are more obtusely angular ; there is no evidence of teeth or crenulations. This shell is readily distinguished by the prolonged posterior extremity, which is obliquely truncated and constricted by a sinus on the base. This character is more conspicuous on the cast than in the perfect shell ; the anterior portion of the shell is more gibbous, and regularly rounded at the extremity. This is a rare species, the form of which I was at first inclined to regard as accidental ; but having seen three specimens in which it is constant, there can remain no question of its title to a place among the species of this period. Fig. 3 a. Eight valve of a specimen on which the shell is preserved. The posterior side of the shell is less extended than in the other specimens. Fig. 3 h. Similar view of a cast, showing the muscular impressions a a. Fig. 3 c. Dorsal view of the same. Position and locality. In the dark colored upper portions of the Trenton limestone at Middleville, Trenton Falls, &c, 192. 2. TELLINOMYA SANGUINOLAROIDEA (n. ^^.). Pl. XXXIV. Figs. 4 a, b. Inequilateral, transversely extended, compressed, subelliptical, narrowed posteriorly ; anterior extremity broadly semi-elliptical ; posterior half sul>cuneate, compressed and acute ; umbones (in the cast) moderately jjrominent, thin, approximate ; cardinal line extended, without visible teeth or crenulations; basal margin regularly curved ; shell thin, closely marked by fine concentric laminas. The only specimen which I have been able to obtain is a cast, and I have seen another in the same condition. It is readily distinguished from the last, by being more compressed, the umbones less prominent, the front more uniformly and regularly rounded, while the posterior extremity is cuneate and the basal margin regularly curved, presenting no evidence of a sinus or depression as in the last. Fig. 4 a. Right valve, showing the posterior muscular impression a. Fig. 4 b. Cardinal view of the same specimen. Position and lucality. In the lower part of the Trenton limestone at Canajoharie and Middleville. tRENTON LIMESTOKE. 153 193. 3. TELLINOMYA GIBBOSA («. 5/;.). Pl. XXXIV. Fi.cs. r. a,b. Subeciuilatoral, transversely extended to a length more than once and a half the height, compressed below and very gibbous towards the iimbones, which arc ])rominent, large and distant, giving a broad space on the cardinal line ; posterior slope oblique ; anterior slope straight, and extended so as to interrupt the curvature of the anterior extremity ; ventral margin with a sliallow sinus below the posterior side of the umbones. The specimen, though not absolutely denuded of the shell, has the markings entirely obliterated. The form and general character of the surface, and, as far as can be determined, the structure of the shell, correspond with the preceding species of this genus. It diflcrs conspicuously from cither of the otliers, in the more prominent umbones and general gibbosity of the shell, as well as tlic more nearly equal extremities. The anterior portion of the cardinal slope is more nearly at right angles to a perpendicular drawn from the beak to the base ; thus giving a totally dilTerent outline to this part of tlie shell, when compared with the other species. The slight sinus in the base is a character approaching to T. nasuta J but in this one it is more nearly central, and less conspicuous. Fig. 5 a. Bight valve of this species, b. Dorsal view. Position and locality. In the central part of the Trenton limestone at Middleviile. 194. 4. TELLINOMYA DUBIA ( «. sp.). Pl. XXXIV. Figs. G a, h, c, d, e,f. Subequilateral, elliptical, the length almost twice the height, the two extremities nearly equal ; umbones subcentral, moderately elevated, with a scarcely prominent ridge along the posterior slope ; anterior extremity regularly rounded ; posterior one often narrower^ and somewhat obliquely truncated or contracted ; shell thin ; surface marked by fine con- centric lines. The structure of the shell is precisely similar to those already described. In this species the umbones are more central than in any other, but the reniaining characters appear sufficient to warrant its arrangement with the previous specimens. Tiie posterior extremity is often contracted, though this appears due to accidental circumstances; for in a great number of specimens examined, much the larger proportion were free from any such characteristic. Fig. 6 a. Cardinal view of the two valves in connection. Fig. G b. Left valve of the same, which is slightly contracted behind. Fig. 6 c. A separate valve, in which the posterior contraction is scarcely perceptible. Fig. 6 d. Left valve of a specimen, in which the posterior side is much contracted. Fig. Q> e,f. Separate valve of an old shell, with a view of the dorsal margin. The specimen is almost cqiiilatcral, and the two extremities arc of nearly corresponding form. 1 Pal.eontologv.] 20 154 PALAEONTOLOGY OT NEW-YORK. Position and locality. This shell, which is more abundant than any other of the order, occurs in the central and higher part of the Trenton limestone at Middleville, Trenton Falls, Herkimer, and other places. 195. 5. TELLINOMYA ANATINIFORMIS ( ?(. sy;.). Pl. XXXIV. Fig. 7. Oblong, subelliptical, slightly inequilateral ; umbones little elevated above the cardinal line, which declines posteriorly ; anterior extremity rounded ; posterior narrower, sub- truncated. On each side of the umljones is a shallow sinus or groove, extending obliquely downward to the posterior and anterior ventral margin. The specimen has only a small portion of the shell remaining upon it, and its structure cannot be so well ascertained, but it appears nevertheless to belong to this genus, though deviating somewhat from the usual characters in the slight oblique fold upon each side of the umbo. The partial truncation in front, and contraction of this part of the shell, are characters common to several species of the genus. This is evidently a rare species, two specimens only having been seen. Position and locality. In the upper crystalline portions of the Trenton limestone at Watertown, Jefferson county. Dr. Crawe. 196. 1. CARDIOMORPHA VETUSTA («.^y>.). Pl. XXXIV. Fig. 8. Subrlioniboidal, gibbous, abruptly rounded anteriorly, sloping abruptly from the posterior cardinal extremity ; umbones nmch elevated, nearly over the anterior extremity ; stuface marked by strong concentric ridges, with small depressions of equal width between. This species is only represented by a single imperfect specimen, which is well exhibited in the figure. The specimen has suffered slightly from compression, and the umbones were probably higher originally than they now appear. I have referred this species to Cardiomorpha of de Koninck, from its analogy in form (o some species of that genus, not having had an opportunity of learning the essential characters on which it is founded. I believe this genus, as well as Edmondin , has been constitutt'd by M. de Koninck for the reception of several Carboniferous species, and it may perhaps be found to preclude tiiose of lower Silurian epochs. Position and locality. In the central part of the Trenton limestone, in thin shaly layers. Middleville, Herkimer county. TBENTON LIMESTONE. li}.} The three following species are of forms w liiclx have heretofore boon referred to tiie genera Cypricahdia, Cardium, &c.; but I am satisfied that this is an improper reference, and that the shells have not the characters of these genera. They approach more nearly to Saxicava and Venerirupis among recent shells, but they differ from any of these. Tiie reference of Silurian fossils to Cypricardia should be regarded with distrust, since species of that genus are so rare among recent shells, and all the fossil species yet referred lo it are of Silurian, Devonian or Carboniferous age ; while thuing the long interval between the latter period and the present, the genus has been al)sent from the fauna of the globe. The most obvious characters of the following species will be found in the rigid straight hinge line, like Cucullea, with the umbones placed near to, or over, the anterior extremity, which, in most instances, is abruptly rounded. Siiells often very gibbous. M. DE Verneuil has suggested to the Author, tiiat several of these will fall imder the genus Edmondia of de Koninck. Not being aljle fully to ascertain tlic cliaracters on which this genus is founded, I plac(; them with some hesitation nader that luuiie. It ui;iy probably be found hereafter that they will require a separation from this genus. 197. 1. EDMONDIA VENTRICOSA («. s;;.). Pl. XXXV. Figs. 1 a. i, ,-. ,/, e,f. Rhomboidal, ctmeate, ventricose above, with the umbones large and prominent, and almost in a line with the anterior margin of the shell ; cardinal line short, from the posterior extremity of which the shell slopes abruptly towards the ventral margin ; posterior dorsal margin compressed ; anterior extremity obtuse ; posterior extremity acute, cuueate ; surface with fine concentric striae. Nearly all the specimens seen are casts, with the surface markings more or less obscuie or exfoliated. By placing the posterior extremity downwards, the shell is obtusely cuneate, dimini.shing rapidly in that direction. The specimens usually found are casts, and suffer various distortions from comj)ression in different directions, giving, in some instances, a widely diflerent form to the shell. Anterior profile cordiform. Fig-. 1 a. Right valve of a large and perfect specimen. Fig. 1 b. Anterior extremity of the sumo, showing the ventricose character of the shell. Fig. 1 c. Dorsal view of the same. Fig. 1 d. Left valve of a smaller individual. Fig. 1 p. Left valve of a specimen which has been compressed vertically, and is covered by a fine striated lamina of shale.* Fig. 1 / Dorsal view of the same. * Many shells, siitlering from pi-essure in the soft shaly rocks, become coated by a thin striated film of sliale, marked like the "slickonsidcs," as if the surrounding parts had been moved after partial solidification. In other instances, there appears to be a collection of shaly matter in a concretionary form around tlie shell, having also a striated surface. This aggregation of matter around the tube of the Orthoeeras, has been regarded as a portion of the animal petrified ; liut it happens eijuallv tn other shells. 20* [55 PALiEONTOLOGY OF NEW-YOKK, The proportions of length and breadth in this specimen are greatly altered by compression, tlie umbones depressed, and the length of the shell apparently increased. Position and locality. In the central and liigher part of the Trenton limestone at Middle- ville, Herkimer, Trenton Falls, Lowville, and other places. («««<« Collection.) 198. 2. EDMONDIAj^SUBTRUNCATA ( n. sp.). Vi.. XXXIV. Fig. 'J ; and Pl. XXXV. Fig. 3 a, b, c. Dorsal and ventral margins subparallel ; anterior extremity abruptly rounded, extending a little beyond the umbo ; posterior slope straight, oblique ; umbones moderately elevated, with an obtuse prominent ridge extending obliquely backwards, and becoming obsolete below ; surface marked by line concentric lines. This species is less gibbous than the following, though it is much expanded below the umbones, and the front very obtuse. A single specimen preserves a portion of the shell, which is marked by fine strias upon the centre and anterior portion ; while upon the posterior slope it presents a few strong subimbricating ridges, which are still marked by the striae. In the casts of this species from the crystalline portions of the limestone, these ridges are often preserved, while other portions are quite smooth. In such instances, there is no evidence of muscular imj)ressions in any part of the specimens. Plato xxxiv. fig. 9. A specimen preserving a part of the shell ; from the soft limestone at Middleville. Plate XXXV. fig. 3 a, b. Casts of the same in the crystalline limestone at Watertown. — fig. 3 c. Cast of the same, showing strong imbricating ridges towards the base. Position and locality. In the central or higher part of the Trenton limestone at Middle- ville, and in the crystalline part of tlie rock at Watertown, (State Cvlhctiou.) 199. 3. EDMONDIA? SUBANGULATA («. s;j.). Pl. XXXV. Figs. 2 a, b. Subelliptical, with the anterior narrowed and slightly projecting ; umbones very pro- minent, subangular, with an obtusely angular elevation extending thence to the posterior ventral margin ; hinge line short, deeply grooved near the margin for the insertion of the ligament ; surface nearly smooth, or marked by fine stria; which become undulating ridges upon the posterior slope. This shell has a greater proportional length than the jireceding, and there is a distinct oblusely angular ridge extending from tlio umbones lUMrly to the posterior ventral margin. Tlie umbones are more angular than the last, the cardinal line shorter, and the anterior margin more extended. Fig. 2 a. Left valve of this species, b. Doisal view of a single valve. Position and locality. In the concretionary lower part of llic Trenton limestone at Water- town, Jefferson county. testate Collection.) TRENTON LIMESTONE. 157 Genus MODIOLOPSIS. [Modiola, and o^]/l^, appearance; from its similarity to Modiola,] Character. Equivalve, inequilateral, elongatetl, becoming broader posteriorly ; uniboncs near the anterior extremity, which is marked by a single strong muscular impression as in Modiola. A sinus often extends from the anterior side of the umbones, obliquely back- wards, leaving the anterior portion separated as a kind of lol)e. Surface marked by fine concentric stri;e ; shell thin. Tliis genus, as defined, includes a very natural group of shells found in the older silurian strata, some of which have been referred to Cvpricardia, Modiola, Pterinea, and other genera. One of the most prominent characters is the strong muscular impression, which is close to the anterior margin : this is often visible in the shell, forming a little circumscribed elevation, and more conspicuous in the cast, where it is usually well preserved. There is often a slight contraction or sinus below, or posterior to, the umbones, Itut tliis is not always conspicuous. The shells of this genus are, for the most part, smooth, or marked only by fine concentric lines, indicating the lamiiue of the shell, and they are generally free from angular ridges. Cypricardites modiolaris (Conrad).* 200. 1. MODIOLOPSIS MYTILOIDES ( 71. . ?;?.). Pl. XXXV. Figs. 4 a, b. Subcyhndrical, enlarging posteriorly ; cardinal line extending about half way from the umbones to the posterior extremity ; umbones small, compressed anteriorly, with a slight depression extending obliquely backwards, and producing a small sinus in the ventral margin ; anterior extremity rounded, with the muscular im]iression reaching to the margin (in the cast) ; posterior extremity becoming broader, and sloping rapidly from the extremity of the cardinal line to the ventral margin ; surface marked by fine concentric lines; cast smooth. This shell is distinguished by its elongated cylindrical furm, and gradual enlargement towards the jiosterior extremity. The anterior side is small, and somewhat abruptly nar- rowed. It is usually found as casts, presenting some remains of the concentric markings ; the musculnr impression is nearly oval, acute above, and contiguous to the margin of the shell. Fig. 4 a. Right valve of a specimen, showing the muscular impression. Fig. 4 b. Dorsal view of the same specimen. Position and locality. In the thin slialy beds near llie upper part of the Trenton limestone, Middleville. (Cabinet of Mr. V.4.su.\em.) * I find myself compelled to abandon the use of the name Cypricardites, as applied to shells difiering so widely as these do from the Cypricardia, and belonging apparently to the Monomvaria and not Dimyaria. So far as it is possible to ascertain, none of the species of the older strata possess two muscular impressions, and therefore do not strictly fall under the genu.s Cypricardites of Conrad (^nn. O'col. Report, isll, p 51). 158 PALEONTOLOGY OF NEW-YORK. 201. 2. MODIOLOPSIS PARALLELA, Pl. XXXV. Fig. .5. Cypricardites paralhla. Conrad in M.S. Subcyliiidrical ; sides nearly parallel ; hinge line extended ; imibones not prominent. I find the above figure among those of the Trenton limestone by Mr. Conrad, marked Cypricardites parallela. Not Iiaving seen the original, I cannot give a full description. It is evidently a species of Modiolopsis closely allied to the preceding one, but distinguished liy its nearly parallel sides and greater extension of the hinge line. 202. 3. MODIOLOPSIS FABA. Pl. XXXV. Figs. C «, h, c, tl. J\ruculites faba, C0NR.4.D. Emmons, Geol. Report, 1S42, pag. 3'J5, fig. 5. Subelliptical or obliquely ovate, ventricose, witli a sinus extending from beak to base ; umbones prominent, near the anterior extremity ; posterior side expanded, sometimes be- coming alate, rounded at the extremity ; muscular impression close to the anterior margin ; surface marl^cd by fine concentric lines, and sometimes a few imbricating lamellaj which leave an impression upon the cast. This species is strongly marked l)y a depression, commencing at the beaks, and becoming broader and deeper below, producing a conspicuous sinus in the base. This depressed line from the beak sometimes appears to divide the two sides of the shell more equally than in others, often leaving the sinus in the base near the centre. The beaks in some specimens, both young and old, approximate towards the centre, giving the fossil a somewhat equi- lateral aspect ; but these characters are deviations from the prevailing ones. It should he observed, also, that the anterior lobe produced by this sinus is often compressed and extended, giving an Avicula-like feature to the shell. Fig. 6 a. A large and characteristic form of this shell, the muscular impression visible at the anterior extremity. Fig 6 A. A smaller specimen, less regularly rounded. Fig. 6 c. A specimen having a more oblique form, with the anterior lobe more compressed and extended. Fig. 6 d. A young specimen, having the umbones and sinus nearly central. Position and locality. In the concretionary layers of the Trenton limestone at Watertown ; in the black comjjact strata of the same rock at Sugar River (Lewis county), and in tiie higher crystalline strata at Middleville. (*''«'<^ CoihcUon.) iX •y .*■ TUENTON LIMESTONE. 159 203. 4. MODIOLOPSIS NASUTUS. ' * Pl. XXXV. Fig. 7. Compai-e Cypricarililcs nasuta, Conrad, Ann. Report, 1811, p. 5i. — — Emmons, Geol. Report, ISia, pag. 103, fig. 4. Elongated ; sides subparallel ; iiniboncs scarcely elevated above tlie cardinal line ; posterior side extended, gradually widening and rounded at t lie extremity ; anterior side contracted and extended into an acute beak ; surface marked by concentric, elevated, and subimbricating lines. This is probably the young of the species which appears in the Hudson-river group^ where it has attained a much greater magnitude. Position and localifi/. In the compact Trenton limestone, Carli.sle (Pennsylvania). 204. 5. MODIOLOPSIS ARCUATUS ( n. sp.). Pl. XXXV. Fig. ^. Obliquely ovate, with a broad sinus below the umbones ; an obtuse subangular ridge extending from the umbones, in a somewhat curvilinear direction, to (he posterior ventral margin ; posterior side broadly spatulate, rounded at the extremity ; anterior extremity narrow, extended ; shell thin, with fine concentric lines. The only specimen of this fossil which I have seen is almost entirely denuded of the shell, a small portion remaining on the lower side. It has the form of an Avicula ; init from its analogy with other species of this genus, I am induced to place it among them. Position and locality. In tlie shaly part of the Trenton limestone at Herkimer. (State Collection.) 205. (J. MODIOLOPSIS SUBSPATULATUS (H.syj.). Pl. XXXV. Figs. U a, b. Somewhat obliquely obovate, the anterior extremity narrowed and truncate ; posterior extremity broadly rounded ; shell compressed ; umbones small, prominent, placed almost in the direction of the longitudinal axis of the shell, and in a line with the anterior ex- Ireraity ; cardinal line ascending rapidly from tlie umbones to the sniimiit of tlie slull ; surface marked by fine concentric lines and a few imbricating ridges ; anterior lobe of the shell small ; sinus obscure ; muscular impression scarcely visible. This shell deviates in a great degree from the typical forms of this genus, and may, perhaps, with the previous one and the two following species, constitute a distinct genus. This species is distinguished from the last, by the more ascending direction of the hinge line, and less extended anterior side, as well as the more rapid expansion of the shell posteriorly. Fig. 1 a. View of the right valve of this species, b. Dorsal view of the same. Position and locality. In the crystalline upper p;ut of the Trenton limestone at Water- town, Jefferson COlUllV. (Ulute Culhcliun.) 160 PALiEONTOLOGY OF NEW'YORK. 206. 7. MODIOLOPSIS LATUS ( a. sp.). Pl. XXXV. Figs. lU a, b. Subrliomboidal, gibbous, broadly rounded below ; umbones prominent, obtuse, not incurved ; anterior side somewhat compressed and subulate, with a slight sinus in the margin, extending beyond the umbones ; posterior side compressed and exjjanded ; surface marked by close imbricating lamellae. This species departs somewhat from the typical form of the genus, but possessing many of tlie essential features, I am not prepared to refer it to any other at the present time. I have been unable to discover the characteristic muscular impression upon this species, though I have indeed obtained no perfect casts, and it may yet be discovered. Fig. 10 o, i. The left valves of two specimens, showing a slight variation in forni. Position and locality. In the upper crystalline portions of the Trenton limestone at Watertown, Jefferson county. 207. 8. MODIOLOPSIS CARINATUS ( n. sp.) . Pl. XXXV. Figs. H a, 4, c. Obliquely subovate, with an acute carina extending from the umbo to the posterior ventral margin ; umbones near the anterior margin, having a depression extending from thence to the base, producing a shallow sinus ; cardinal line extending little more than half the length of the shell ; posterior extremity obliquely truncated ; the slope between the margin of the shell and the carina occupies more than one third the entire surface ; surface marked by conspicuous elevated lines, which become more prominent and coalesce towards the anterior extremity. The anterior portion of this shell closely resembles the M.faha; but it is readily dis- tinguished from that one, and all other species of the lower rocks, by the conspicuous carina which marks the posterior slope. It is a rare shell, few specimens having been found. There is a very similar species in the Hamilton group, but it is distinguished by the less prominence of the umbones, which are not so near the anterior margin, and by the two sides of the shell being more nearly parallel ; the stria;, also, are sharper and more distinctly defined, and the posterior truncation is more nearly vertical. Fig. 9 a. A large specimen, with prominent umbones. Fig. 9 J. A smaller specimen, showing the true form of the shell more distinctly than the last. Fig. 9 c. A smaller spiximen, in which the posterior margin is less oblique. Position and locality. In the compact central portion of the Trenton limestone at Middle- ville. Mr. Wadleigu. tUENTON LIMESTONE. 161 208. 9. MODIOLOPSIS AVICULOIDES (n. s/).). PL. XXXVI. Figs. 1 o, 6. Obliquely ovate, ventricose ; cardinal line very obli(iue ; iirnboncs prominent, with an obtusely suliangular ridge extending to the posterior ventral margin ; a sliglit parallel depression just forward of theumbones ; posterior side somewhat extended and compressed, having a winglike appearance ; anterior extremity pointed, and projecting slightly beyond the umbones ; surface marked by fine concentric lines and a few prominent undulations. The specimen figured is somewhat imperfect, the compressed posterior margin i)eing broken off; and the anterior extremity has apparently suffered a litlle pressure. In its general features it resembles other species of this genus, being closely allied to Modiolopsis viytiloides. Fig. 1 a. A view of the left valve of this specimen, b. Dorsal view of the same. Position and locality. In the thin shaly layers which alternate with the more compact strata in the central part of the Trenton limestone at Middleville. 209. 10. MODIOLOPSIS? TRENTONENSIS. , ■ -. Pl. XXXV. Fig. 10. * ' ^ This figure is given by Mr. Conrad, as a species of CvPRicAnoiTES from the Trenton " -^ limestone. It bears so many characters analogous to the larger species of Modiolopsis, that - I have referred it to that genus, giving the figure to call the attention of geologists to the existence of such a species in the rock. r 210. 1. AVICULA TRENTONENSIS. ' .> Pl. XXXVI. Figs. 2a,b,c,d. Avicula trentonensis. Conrad, Jour. Acad. Nat. Sciences, Vol. viii. pag. 210, pi. 12i fig. 10. — aviformis. Id. lb, pag. 213, pi. 13, fig. 11. Obliquely obovate, gibbous, expanding towards the posterior extreniily, which is some- what obliquely truncated from the extremity of the hinge line, narrowed anteriorly, and constricted just below the umbones ; anterior wing small, acute; posterior wing narrow and long, forming a kind of border to the shell ; surface marked by strong radii and concentric subimbricating ridges. . ■ An examination of several specimens has convinced me that the two species cited above are identical. In perfect specimens, the surface is marked by strong radii and less distinct concentric undulations. In worn or macerated specimens, the radii become obscure or obsolete, and the concentric elevated ridges become more distinct. The two valves are [ Pal.eontology.] 21 •(.'■■ ■ 162 PALEONTOLOGY OF NEW-YORK. equally convex, and marked alike in perfect and unworn specimens. There is often a slight difference in the form of the anterior wing, as will be seen on reference to the figures ; and the posterior extremity is often obtusely angular, and sometimes rounded, depending on the oblique truncation. This shell approximates very nearly to the Modiolopsis arciiatus (PI. XXXV. fii^. 8); but the posterior extremity in that is broadly rounded, and there is no evidence of a posterior wing. The one under consideration presents obscure evidences of a posterior wing in the marginal expansion of the shell ; and this, with the existence of diverging radii, remove it from the preceding genus. Fig. I a. A worn specimen, showing only obscure traces of radii, with strong concentric ridges. (This figure is taken from the original of A. avlformis.) Fig 1 b. A similar specimen, with obscure radii, having the anterior wing more extended. Fig. 1 c. The opposite valve of a specimin of similar form as the last, with the radii better preserved. Fig. 1 d. A large specimen of the left valve, with strong radii. The presence or absence of the radii is here clearly shown to be due to wearmg of the surface. Position arid locality. In the compact central and higher portions of the Trenton limestone at Middlevillc, and in the calcareous layers in the Utica slate at Coldspring, Montgomery county. ' (State Collection.) 211. 2. AVICULA ELLIPTICA (7). .5^.). Pl. XXXVI. Fig. 3. Compare ./Ivicula obliqua, Sowerby, Sil. System, pag. 035, pi. 20, lig. 4. Incquivnlve, subelliptical, narrowing towards the anterior extremity, compressed ; uinbones small, their direction nearly rectangular to the hinge line ; posterior wing tri- angular, distinct above, and gradually merging into the margin of the shell ; anterior margin sloping from the beak with a gentle curve, without a well defined wing; cast of the muscular impression in the left valve oblong, rounded above, and somewhat diverging' and striated below ; surface marked by a few obsolete concentric lines. This specimen has the greater part of the shell removed, and perfect specimens may possess characters not obvious in this one. It corresponds in many respects with the one cited above, and its similar geological position induces me to regard it as an analogue at least. It is doubtful if this species belongs to the true Avicula, and it may be found to approach more nearly to the foUov/ing genus, which is distinguished from tiie Avicula by some characters possessed by this. Position and locality. In the fine-grained black limestone, central part of the Trenton limestone at Middlevillc. A rare shell. trenton limestone. 163 Genus AMBONYCIIIA. [Greek, a(A,3uv, the boss of a shield, and ovk|, a claw or talon ; in allusion to the rounded incurved unibenes in the typical species] Character. Eqiiivalve, itic(iiiilatei;il, compressed, alatc or siibalate posteriorly, obtuse and abiiiplly decliiiiiiij or curving downwards on tlie anterior margin. General form some- what ol)li((tiely ovale, gibbous or iiillated towartls the iiiiibones and on the centre of the shell ; cardinal margin very oblique, or approaching a line parallel to the direction of the umbones, which are often incurved at the extremity, and equal, or project beyond, the line of the anterior extremity ; surface marked by more or less prominent concentric striae, strong undulations, or fine radiating stria-. Muscular impressions large : one in each valve. The description includes several species of fossil shells, which, in some respects, vary in ciiaracter, while, so far as regards general form ;ind otlier prominent features, they evidently form a natural group. This genus may be again subdivided, when we become better acquainted with the species which are at present arranged under it. Several of these species have heretofore been referred to Inoceramus, and Pterinea, to which they bear some resemblance ; but have a structure of the hinge different from the former, as well as being equivalvc ; w'hile they differ from authentic specimens of the latter, in having no anterior alation, which renders it desirable to distinguish these early forms by another name. It appears probable that Pterinea carinata of Goldfuss may be referred to the same genus, not being a true Pterinea accordinof to the definition of that author. , . 212. 1. AMBONYCHIA BELLISTRIATA ( n. i;).). -■ ■ Pi,. XXXVI. Figs. 4 a, 4, «. Obliquely subovoid, ventricose, very inequilateral, height much greater than the length ; umbones very ventricose, and extended into long and incurved beaks, which bend forward at their extremities ; anterior margin not alated, or extending beyond the beaks ; posterior side compressed, subalate ; base regidarly rounded ; cardinal line short, very oblique to the umbones ; surface marked by fine radiating stria?, with a few elevated concentric lines of growth. This beautiful fossil shell is readily distinguished by its external form and markings. The umbones are extended into long incurved beaks, which are very ventricose, and rise abruptly from the shell towards the summit; the central and lower part of the shell is regularly convex, becoming more compressed towards the margin. The anterior side extends almost in a right line from the beaks towards the base. Fig-. 4 a. Left valve of a very symmetrical specimen. Fig-. 4 i. Right valve of a larger specimen. 21* . 164 PALEONTOLOGY OF NEW-YORK. Fig. 4 c. Profile view of the same. The specimen appears to be inequivalve, which is due to the sliding down of one valve below the other, as is clearly shown in the lower part of the figure, and in 4 b. Fig. 4 d. A portion of the surface enlarged, showing the fine undulating strice crossed by the concentric lines of growth. Position and locality. In the central part of the Trenton limestone at Middleville, Trenton Falls, &C. (Cabinet of Mr. Moore, of Trenton Falls.) 213. 2. AMBONYCHIA ORBICULARIS, Pl. XXXVI. Figs. 5 a, b, c, d. Pterinea orbicularia. Emmons, Geol. Report, 1842, pag. 397, fig. 3. Rhomboidal or siiborbicular, very ventricose in the middle and upper parts of the shell, regularly curved anteriorly, and somewhat compressed and alate behind ; umbones ven- tricose, narrowing above, very prominent, extended and incurved into a kind of hook or claw, which turns forward at the extreinity ; cardinal line moderately extended, straight ; surface of the shell ornamented by fine radiating stria', which are crossed by sharp concentric elevated lines ; cast smooth, marked by the large oval muscular impression of the shell. This species, in its young state, bears considerable resemblance to the preceding one ; but the radiating striae are always stronger, and distinctly marked by concentric lines ; and the shell is wider, though it does not attain so great a proportional width in the young as in the older specimens. It is not rare in the concretionary limestone at Watertown, where it is usually found in the condition of a cast, the material of the shell forming a thin crystal- line coating upon the surface, in which the original structure is not apparent. In a few specimens, I have detected small portions of the beautifully marked shell represented in fig. 5 d. The proportions of heiglit and breadth, shown in the figures, sometimes varies ; but the usual forms of perfect specimens are there represented. The associates of this shell are a single species of Tellinomya {T. anatiniforms) , Modiolopsis fnba, Edmondia suhangulata, and a slender Orthoceratite. The Edmnndia subtrnncata, E. ventricosa and E. vndata, occur in a higher position, where the present species is never seen. Fi.j. 5 a. Right valve of a specimen, showing the muscular impression. Fig. 5 b. Left valve, retaining a portion of the shell, which is beautifully ornamented by radiating and concentric stria;. Fig. 5 c. Anterior profile view of a single valve. Fig. 5 d. A portion of the shell enlarged. Position and locality. This shell occurs in the lower concretionary and irregularly bedded Trenton limestone at Watertown, Jefferson county. TRENTON LIMESTONE. 1G5 214. 3. AMBONYCHIA AMYGDALINA (n. sp.). Pl. XXXVI. Figs. 6 a, ft, c. Obliquely ovate or elliptical, with the iimboncs extended, height much greater tiian the length ; unibones oblique, nearly parallel to the anterior margin, and bending forward at the apices ; anterior margin obtu.se, straight for a short distance below the beak, and thence broadly curving around to the base ; surface regularly convex in the middle, becoming gibbous above ; posterior margin compressed, subalate. The only specimen known is a cast, from which the figures and descriptions arc taken. It will be readily recognized by the form, which differs from that of any other species. The lower part of the specimen presents a very regular elliptical figure, intercepted above by the oblique direction of the lunbones, which are slightly curved forward at the e.vtremi- ties. The anterior edge presents a distinct oblong lunule beneath the apices of the umbones. A few obscure undulations are visible upon the cast, but nothing from which the character of the original surface can be ascertained. Fig. 6 a. Right valve of this specimen. Fig. 6 b. Profile from the posterior side. Fig. 6 c. Profile of the anterior extremity, showing a kind of limule below the beaks. This siJccies resembles in form Inoceramus rostratus, a .species from the Lias (Goldfuss, Petrcfada, Vol. ii. pag. 110, tab. 115, fig. 3 a, 6). Position and locality. In the higher part of the Trenton limestone at Adams, Jefferson county. Its associates are Murchisonia, Pleurotomaria, Jltrypa bisulcata, and fragments of Ort/ioceratites. 215. 4. AMBONYCHIA UNDATA. Pl. XXXVI. Figs. 7 a, ft. Plerinea undosa. Conrad in MS. — undata. Emmons, Geol. Report, 1842, pag. 39.'), fig. 1. Compare Inoceramus vttuslus, Sowerby, Min. Conchology, 1829, Vol. vi. pag. 102, tab. 5S1, fig. 3. — — var. priscus, Portlock, Geol. Report, 1843, pag. 423, pl. 32, figs. 1, 2, 3. — — Goldfuss, Petrefacta, 1S34 - 1S40, Vol. ii. pag. 107, tab. lOS, fig. 5. Obliquely ovate or subrhomboidal, with the base rounded, ventricose ; anterior margin obtuse, straight above and curving below ; posterior margin compressed, scarcely alate above ; cardinal line straight, oblique ; umbones ventricose, elevated, narrowing above and scarcely incurved, with the extremities bending forward ; surface with broad, smooth, concentric undulations, which curve downward more abruptly on the centre of the shell ; anterior side scnrcely concave below the lieaks ; no definite lunette. 166 PALEONTOLOGY OF NEW-YORK. This species has been referred to Pterinea by Mr. Conrad, witli the remark that it " has much resemblance to certain species of the Genus Inoceramus." It is probably identical with that described by Mr. Portlock (cited above), who adds the remark, that Professor Phillips regards it as belonging to the Genus Posidonia of Bronn. It is true that our shell approaches to Posidonia in many respects ; but in other essential characters, it differs from that genus. The species here grouped under a new generic name, may be regarded, perhaps, as the representatives of a type, which, in a later geological period, appears in the Posidonia ; but the species under consideration, and its congeners, cannot, I apprehend, be properly placed under the Genus Posidonia. Strictly speaking, the present species has few of the distinguishing characters of Inoceramus, except the broad undulations which mark some species of that genus as well as of Posidonia. It cannot therefore be admitted into that genus, and we are compelled to construct a new term, under which tliis and the preceding ones may be arranged. Our species bears a close analogy with Inoceramvs vetustus of Sowerby, from the Carboniferous limestone ; but that one is more distinctly alated, both as represented by Sowerby and by Goldfuss : neither can we, for a moment, believe that this species of the older Silurian rocks, after such an immense lapse of time, should reappear in the Car- boniferous strata, while we have scarcely an analogous form in all the intermediate strata. If the geological position of Mr. Sowerby's specimen be correctly cited, it is not probable tiiat the one described by Capt. Portlock is identical ; for from its associates, as well as precise similarity to our own, we regard it as of lower silurian age. Fig. 7 a. Right valve of a specimen which is imperfect on the lower side. Fig. 7 b. Profile of the same, looking upon the posterior side. Position and locality. In the higher crystalline portions of the Trenton limestone, asso- ciated with Edmondia subtruncata, Subulites elongate, and several of the common Brachio- pods of the rock. Watertown, Jefferson county. (State Collection, from Dr. Crawe.) TRENTON LIMESTONE. 167 216. 5. AxMBONYCHIA OBTUSA ( n. sp.). Pl. XXXVI. Figs. Sa,b. Obliquely ovate, short, gibbons ; mnboncs short, obtuse, scarcely incurved or bending forwards ; shell somewhat compressed towards tlie lower margin, convex on the centre and becoming inflated above ; anterior side obtuse, rounded, scarcely extending beyond the umbones ; posterior side compressed, scarcely alated ; cardinal line straight, margin of the shell curving from its posterior extremity ; surface? The specimens seen are casts, where the markings of the shell are not preserved. This species is distinguished from the others by its short ovate form, as well as the shorter, very obtuse and gibbous umbones. It departs somewhat from tiie typical forms of the genus; but it has nevertheless the essential features, and cannot be referred to any other genus. I have a specimen from the northwest part of Wisconsin, which is apparently identical with the one here figured, but presents a slight ridge extending from the summit down the anterior side of the shell, as if produced by a contraction in that direction. The specimen is a cast, differing in no otiier respect from the one figured. Fig. 8 a. Right valve of this species, b. Profile view from the posterior sid& Position and locality. In the higher part of the Trenton limestone, associated with the preceding, at Watertown. '■ ■ ' 217. 6. AMB0NYCHIA1 Pl. XXXVI. Figs, 'i a,b. ' The specimen here figured has been unfortunately lost, so that a description cannot be given. It bears in some respects the characters of the present genus, but is equilateral, with a distinct prominent umbo. The surface is marked by thin sharp concentric ridges, as shown in the figure. Fig. 9 a, b. View of the single valve, and profile of the same. Position and locality. In the thinbedded higher portions of the rock at Middleville. There are several other species of the preceding, or allied, genera of Aceph.4l.\, in the Trenton limestone ; but the condition of the specimens which I have seen is such that they cannot be satisfactorily described. Furtiier examination will doubtless increase the number, and render us better acquainted with the character and relations of those already described. Notwithstanding that several of these species are widely distributed, and may be found in almost every locality of the rock, they are never abundant. Of several species, only two 168 PALiEONTOLOGY OF NEW-YORK. or three specimens have been seen, and careful researches have been but poorly rewarded. It is evident from what we find in subsequent formations, that the nature of the sediment, or the condition of the ocean, was not favorable to their development during this period. In this respect they contrast with the species of Brachiopoda, which, for the most part, are abundant in one or more localities. An interesting comparison may be drawn between this and the subsequent period, or a later part of the same epoch, during which the shales of the Hudson-river group were deposited. In the latter group, the Brachiopoda known, with the exception of two species, are identical with those previously found in the Trenton limestone ; while the species of AcEPHALA are, for the most part, distinct from previously existing forms. Several species of those already described do appear in the shales and sandstones of the Hudson-river group ; but a large majority of the forms are quite distinct, though belonging to the same genera. From these facts we are able to infer that the condition of tlie ocean, during the deposition of the calcareous strata, was more favorable to the development of the Bra- chiojjoda, than of the Acephala ; also that the former are less susceptible to the influence of change, or more enduring than the latter, which, with the exception of three species, are not known in the succeeding strata. We shall find, also, in all subsequent palaeozoic formations, that the calcareous strata have proved comparatively barren of the Acephala, though very prolific in the Brachiopoda; while, on the contrary, the periods of sandy and shaly deposits have been far more pro- ductive of the Acephala, with a comparatively larger proportion of Brachiopoda than we find of the Acephala in the calcareous deposits. We must take into account, however, in making this comparison, the character of both the calcareous and other deposits ; for, as in the case of tlie Trenton limestone, we may have a considerable proportion of shale ; and in formations where the other materials predominate, we shall find also a large amount of calcareous matter. In such instances we usually discover, as in the present case, that the Brachiopods are most abundant in the calcareous part ( often, perhaps, constituting a large proportion of the same), while the Acephala occur in the shaly part of the formation. In the present instance, we have an opportunity of making a comparison with the same formation in its western extension, where the subdivisions made in New- York are scarcely recognizable, showing that the Acephala are less abundant throughout the formation than in New-York ; while several of the species known here in the higher part of the formation, occur there in a lower position, and others ascend perhaps quite to the upper limits of the formation, and there become more numerous than elsewhere. rRENTON LIMESTONE. 169 GAISTEROPOBA OF THE TRENTON LIMESTONE. Plates XXXVIL, XXXVIII., XXXIX. & XL; We aio at present acquainted wiili about tliiity species of this order in the Trenton limestone. One or two of tliese are icnovvn in a lower position, and ai)oiit the same number pass upwards into the shales of the Hudson-river group. Tiiey belong mainly to the genera Pleurotomaria and Murchisonia, with a few others which cannot be satisfactorily referred to these genera. There are, also, one or more species of Bellerophon, and some others of an allied genus. A few of the species only are abundant and widely distributed, while the others are comparatively rare and circumscribed in their distribution. Shells of this order are apparently more numerous in New-York tiian in the western extension of the same formation, where we know, at present, but few sj)ecies. Two or three forms, however, are quite frequent in western localities, one of which, and the most abundant, has not yet been satisfactorily identified in New-York. Unfortunately for accurate determination, many of these species are usually found as casts, the shell having been removed ; and it is only in favorable localities that the characteristic surface markings are preserved. Several species have never been seen except as casts, and these can only bo determined by their general form and proportions. '■•' . Genus HOLOPE A. • [ Greek, okog, entire, and o*<), an aperture ; in allusion to the entire margin of the dperture.] Character. Shells conical, ventricosc, more or less oblique or nearly direct ; aperture round ovate ; margin entire ; surface marked by simple fine curved striae, or cancellated. The shells constituting this genus have the general form of Turbo or Palddina, differing somewhat in the form of the aperture. They are distinguished from the Pleurotomaria by the absence of a slit in the margin of the aperture, or of angular bending in the striae upon the surface, as well as being generally more ventricose, and the volutions more regularly rounded. There are also some other reasons for separating these shells from the Genus Turbo, which probably had not come into existence at so early a period ; since most of those here- tofore referred to it, and other allied genera, have been subsequently discovered to belong to distinct genera, and to possess reliable characters for their separation. As examples of these, may be instanced Murchisonia and Loxonema, which have become well known within a short time, and generally distinguishable from other genera by obvious characters. The two forms in the Calciferous sandstone, referred to the Gcntis Turbo, probably belong to the genus here proposed. I Pal.«ontology.] 22 170 PALAEONTOLOGY OF NEW-YORK, 218. 1. HOLOPEA SYMMETRICA (n. 573.)- Pl. XXXVII. Fig. 1. Spire conical, elevated, apex acute ; height much greater than the breadth ; volutions four or live, rounded, ventricose, increasing gradually from the apex ; surface marked with fine, crowded striae, which curve gently backwards from the sutures ; aperture nearly circular. This is a very pretty symmetrical shell, with the spire elevated and the volutions ventricose, resembling some species of Paludina. The striae are fine, close, and sometimes crowded together and elevated in fascia or undulations. All the specimens examined present the uniform character here given, and show scarcely a perceptible variation even in the size of the shell. Position and locality. In the upper crystalline portions of the limestone at Middleville. (State Collection.) 219. 2. HOLOPEA OBLIQUA ( n. sp.) Pl. XXXVII. Figs. 2 a, b, c, d. Spiral, oblique, height and breadth nearly equal ; spire very short, acute at the apex, composed of three or four volutions, diminishing rapidly above, the last one very ventricose; a_perture somewhat circular, entire, transversely extended, with the outer lip thin ; surface smooth, or covered with fine striae. This shell has heretofore been referred to the Genus Natica, from its general resemblance, though it is not probable that it is a true Natica. It is more oblique, and the spire is shorter and more abruptly acute than in either of the other species described. The aperture, in two specimens examined, is rounded upon the outer side, contracting towards its junction with the body whorl. In the largest specimen seen, the surface is marked witlr vertical curving undulations or rounded ridges ; but these appear due to age, or other circumstances not constant in their inlluence, though something of the kind is obscurely visible in another specimen. The volutions are somewhat more appressed at their junction than the succeeding Species. Fig. xJ a. View of the aperture of a small specimen. Fig. 2 b. View of the back of the shell. Fig. 2 c. Pi ofile view of the same. Fig. 2 d. Back of a larger specimen. Position and locality. This species occius in the higher shaly part of the Trenton lime- stone at Middleville. Tiie specimen fig. 2 d is from the upper crystalline portion of the rock at VVatertown, Jefferson county. (State Collection.) TRENTON LIMESTONE. 171 220. 3. HOLOPEA PALUDINIFORMIS. Pl. XXXVIT. Figs. 3 a, b. PleUTotomaria. Emmons, Geol. Report, 1842, pag. 397, fig. 1. Spiral, scarcely oblique, elevated ; height greater than tho breadth ; volutions four or more, rounded, ventricose, enlarging somewhat rapidly from the apex ; aperture round ovate ; surface] The specimen is a cast, preserving no surface markings. This species resembles the first described, but it is comparatively more gibbous, and the spire less elevated in proportion to the size of the shell. In form and aperture, it closely resembles the larger Paludin^. . . Fig. 3 a. View of the back of the shell, b. View of the aperture. Position and locality. The only specimen known, is from the crystalline upper part of the Trenton limestone at Watertown, Jefferson county. (State ColUctioTi.) - ' 221. 4. HOLOPEA VENTRICOSA (n.:jp.). ■ Pl. XXXVII. Figs. 4 tt,b. Spiral, oblique, subglobose, very ventricose ; height and breadth nearly equal ; spire short ; volutions about three, rounded, rapidly enlarging from the apex, and becoming ventricose ; aperture rounded oval, slightly contracting at the upper side ; surface ? The specimen is a cast, preserving some slight evidences of stria as in fig. 1, which appears to have been the prevailing character of the markings on the surface. But few specimens of either of the species have been seen, and they are much more rare than the Pleurotomaria, and occur almost entirely or altogether in the upper part of the rock. Fig. 4 a. View of the back of the spire, b. View of the lop of the spire. Position and locality. In the upper crystalline part of tlie Trenton limestone at iMiddle- ville, Herkimer county. Several other imperfect specimens, apparently referable to this gentis, have been observed in the Trenton limestone, but none of them in a condition to furnish specific characters. There are smooth casts of Pleurotomaria, resembling in general form these or smaller species of the same genus, being sometimes regularly rounded ; but in most instances they preserve some evidence of the angular form of the last volution, which is never seen in the HoLOPEA. 22* 172 PALEONTOLOGY OF NEW-YORK. 222. 10. PLEUROTOMARIA SUBTILISTRIATA (n. .^/j.). Pl. XXXVII. Figs. 5 a, ft, c, tl. Lenticular ; spire niiicli depressed ; volutions four or five, even, smooth, forming a verj'^ depressed cone, with an elevation little more than one third the width of the shell ; aperture transversely extended into a somewhat triangular form ; umbilicus very small ; surface marked by fine close striae, whicli bend gently backwards on the upper half of the volution, and more abruptly on tlie lower half, finally running almost parallel to the outer margin ; outer margin of last volution sharply angular, with a mesial band parallel to the edge, indicating the generic character of the shell. This species is much smaller and more depressed than either of the others, most of the specimens being scarcely visible to the naked eye. The siuface is apparently smooth, but under a magnifier, is clearly marked by fine strife as described. The outer volution is slightly concave near the margin, the others being plane. Fig. 5 a. View of the spire of a large specimen. Fig. 5 b. Profile of the same. Fisf. 5 c, d. View of the spire and profile of the largest specimen seen. Position and lucality. This species is known to me only as occurring in the concretionary and irregularly bedded limestone, near the base of the Trenton limestone, at Watertown, Jefferson county. 223. 11. PLEUROTOMARIA LENTICULARIS. Pl. XXXVII. Figs. 6 a, b, c, d. Trochus lenticularis ( .' ) Sowekby in Sil. Researches, 1839, pag. 642, pl. 19, fig. 11. Pleurotomaria lenticularis, Conrad iu MS. Emmons, Geol. Report, 1842, p. 392, f. 2; p. 393, f. 2 & 3. Compare Hclicitts gualleriattis, Schlotheim, 1820, Petrefacta, p. 103; Id. Nachtrage, pl. 11, fig. 3. — ubvallatiis, Wahlenberg, 1821, Act. Soc. Sci. Upsal, Vol. viii. pag. 73, pl. 4, f. 1 & 2. Solarium pctropolitaniirn. Pander, 1S30, Beitrage zur Geogn. Russland, pag. ISO, pl. 1, fig. 3. Euamphalus pseuduqualteriatus, Vo.v Buch, 1S3U, Karst. Archiv, p. 156 - li3S. Delphinula obvallalo, Hisingeb, 1S31, Petrif. de la Suede, p. 8. JEuomphalus qualttriatm, Goldfuss, 1834, in Kloden Verst. Brandenburg, p. 155. — — Bronn, 1835, Leth. Geognostica, pag. 94, pl. 2, fig. 1. — pseudoqualteiiatus, Hisinger, 1837, Leth. Suecica, pag. 36, pl. 11, fig. 5. — gualteriatm, Eschwald, 1840, Sil. Syst. in Esthland, p. 115. — — Goldfuss, 1844, Pettef. Germanica;, Vol. iii. pag. 81, pl. 189, fig. 3 a, b. — — VEHN.EUIL, 1845, Pal. Russia and the Ural Mountains, pag. 333, pl. 23, fig. I a,b ; and var. A. fig. 2 a, b. Not Pleurotomaria lenticularis, Goldfuss, Petrefacta, Vol. iii. pag. 65,- pl. 183, fig. 2. Lenticular; spire depressed, subdiscoidal ; volutions scarcely four, flattened above, last one obtusely angular at the margin and somewhat ventricose below ; aperture transversely extended, subtrigonal ; umbiHcus large, c.Klcnding to the apex ; surface marked by fine stria;, which curve gently backwards from the suture, making an abrupt retral bend in passing over the angles of ihe last volution. TRENTON LIMESTONE. 173 This species usually occurs as casts of the interior, the siicll being rarely preserved. I have seen a single specimen in which some remains of the shell can be distinguished ; and there is also an obscure indication of the spiral band on the angular margin of the last volution, but the details cannot be made out. This species is probably the same as that described by Mr. Sowerby, cited above ; and its similar geological position is a further reason to regard it as identical. It possesses the essential cliaracters of Pleurotomahia, whicli are better seen in the analogous succeeding species. This species is regarded by M. de Verneuil as identical with Euomphalus qualteriatus, cited above ; but it appears to me that there are some reeisons for separating it. That species, judging from the figures of Sciilotheim, Wahlenberg, Hisinger, Goldfuss and DE Verneuil, is less depressed than our shell, and the last volution below the angle more vertical and ventricose, giving the aperture a different form as represented by the antliors quoted, that of Wahlenberg approaching more nearly to our shell, but being insufficiently extended tiansversely. In our specimens, the extent of tiie aperture, from the suture with the next volution, is greater than the vertical height ; while in the figures cited, except that of Hisinger, the vertical diameter is equal to, or greater than, the transverse, and, in that of Goldfuss, nearly twice the transverse extent from the suture to the outer angle. Our specimens are very uniform in character, and we can scarcely conceive such a change to have taken place in the same species on the other side of the Atlantic. The succeeding species bears a more close resemblance to the E. qualteriatus, in the form of the aperture and expansion of the last volution. Fig. 6 a. View cf the spire (the specimen is a cast). Fig. 6 b. Lateral view, shewing the elevation of the spire. Fig. 6 c. Base of a smaller specimen (a cast), showing the umbilicus. Fig. 6 d Front view of the same, showing the aperture. Position and locality. This fossil is more abundant in the higher crystalline portions of the rock at Watertown, than at any other locality. It is rarely found at Middleville, and other localities in the Mohawk valley. At the first named locality, it is more abundant than any other univalve in the rock, except the Belleroplion bilohatus. {State Collection.) 224. 12. PLEUROTOMARIA ROTULOIDES (n. ,?;).). Pl. XXXVII. Frgs. 7 a, b, c. Compare Euomphalus qunllcriattis, and synonymy as in tlie preceding s))ecies. Depressed conical ; spire composed of about four volutions ; height about ecpial to half the width of the shell ; outer volution angular at the margin, ventricose below and slightly concave above ; upper ones becoming convex above, and slightly elevated vertically at the suture •, umbilicus small ; aperture subqiiadrate ; surface marked by distinct sharp stria, which curve gently backwards from the suture above ; edge of the outer \olution distinctly markeil by a spiral band, with abruptlv curving striie, indicating the marginal slit. 174 PALEONTOLOGY OF NEW-YORK. This species, in form, bears considerable resemblance to the one cited above ; but it is uniformly smaller, more distinctly striated, and has the spire more elevated, with the volutions vertically elevated at the sutures. TJie umbilicus is also smaller than in E. qual- teriatns, and the outer margin less nearly vertical. It is distinguished from the preceding species, with which it has usually been confounded, by the greater elevation of the spire and the convexity of the volutions, and also in the form of the aperture, which is nearly subquadrate. It is a very neat symmetrical species, occurring much more rarely than the P. lenticularis. Fia-. 7 a. View of the aperture and front of the shell, showing the elevation of the spire. Fig. 7 b. View of the top of the spire. Fig. 7 c. View of the base, showing the umbilicus. Position and locality. In the lower part of the Trenton limestone at Middleville. 225. 13. PLEUROTOMARIA SUBCONICA ( n. sp.). Pl. XXXVII. Figs. 8 a, b, c, d, e. Compare TrocMis eUiptieus, Hisinger, Leth. Suecica, pag. 3.5, pi. 11, fig. 1. — ttochifurmis, Porilock, Geol. Rep. Londonderry, 1843, pag. 414, pi. 30, fig. 9. Trochiform ; spire elevated, apex acute ; volutions about five, flattened above, with a projecting carina just above the suture ; last volution strongly carinated on the outer edge, and marked with a spiral band, ventricose below ; aperture transverse, subquadrate, an- gular on the outer side and round below ; surface marked by fine striae, which bend gently backwards from the suture, and more abruptly on the lower part of the whorl ; spiral band a distinct groove, margined by sharp elevated edges, upon which the striae bend Iiackwards in an abrupt curve; below this the striae bend gently forward, and thence curving back- wards, terminate in the umbilicus ; longitudinal striae crossed by transverse sharp elevated lines which are finer than the longitudinal ones. This is a beautiful trochiform shell, with a symmetrical conical spire, and beautifully cancellated surface. The finer concentric striae are often obliterated from wearing or ma- ceration, the longitudinal ones only remaining, and these also are often obliterated. The spiral band is distinct on the last volution, and the striae upon it appear to be crowded into ridges. The suture is formed just at the lower margin of the band, leaving it visible at the lower edge of the higlier volutions. In casts of this species, the outer angle of the last volution is distinctly carinated, as also the lower margin of the higher volutions. Fig. 8 a. Front view of a specimen preserving the shell in a very perfect manner ; the aperture im- perfect. Fig 8 b. Base of the same, showing the small partially closed umbilicus. Fig. 8 c. An enlarged portion of the surface, showing the cancellated strije which arc scarcely visible to the naked eye. Fig. 8 d. Cast of another specimen. Fig 8 e. Front view of the same, showing the form of the aperture. TRENTON LIMESTONE. 175 These figures are of specimens of the ordinary size ; they are frequently smaller, and others attain an elevation of nearly two inches. Position and locality. This species occurs in the lower part of the Trenton limestone, near its junction with the Black-river mass, at Watertown, Jefferson county. I have also seen the same species in the shales of the Hudson-river group at Turin and Pulaski. (State Collection ; Cabinet nf Dr. Chahe.) 74. 7. PLEUROTOMARIA UMBILICATA. Pl. XXXVIII. Figs. 1 a, b, c, d, e,f, g. Reference Pleurotomaria vmbilicata, pag. 4-3, pi. 10, fig. 9 of this volume. This variable species is widely distributed in the Trenton limestone, occurring in nearly all localities of the rock. The description of the forms in the Birdseye limestone apply to those of the Trenton limestone, though they are usually better preserved in the latter rock. The last volution is sometimes angulated along the margin of the umbilicus ; and, in a single specimen, apparently not differing specifically, there is an additional carina on the side of the shell. If this prove only a deviation from the prevailing character Of the shell, we may be inclined to refer the P. quadricarinata ( page 43 of this Report) to the same species. The specimens, in both instances, however, are much compressed and partially distorted, so that further examination may be required to determine this point. The specimen fig. 8 «■ is from Mineral Point ( Wisconsin) , having the upper part of the spire rejilaced by sulphuret of lead. It is apparently identical with the New- York specimens, though the spire appears to be more elevated than in the prevailing forms. Mr. Conrad (Proc. Jicad. JVat. Set. Philadelphia, Vol. i. p. 330) regards this shell as identical with Pleurotomaria angulata of Sowerby [Sil. System, pag. 641, pi. 21, f. 20); but in this species, the cast of the volutions is distinctly biangular, thus differing from the figure of Sowerby. Fig. 1 a. Back of the shell, showing an elevated spire. Fig. 1 b. Front view, showing the aperture. Fig. 1 c. Base of the shell, showing the umbilicus. Fig. 1 d. View of the top of the spire of a larger specimen. Fig. 1 e. Front view of the same, showing a depressed spire. Fig. 1 / Base of the same, showing the large umbilicus. Fig. 1 g. Specimen from Mineral Point, showing a greater elevation of the spire. Position and locality. This species occurs in almost every part of the Trenton limestone, usually in the intercalated shaly strata, and more rarely in the compact or crystalline portions of tlie rock. It has been found at Middleville, Herkimer, Trenton Falls, Lowville, Turin, Watertown and Adams, and probably occurs in many other localities. This species has already been shown to exist in the Birdseye limestone, and it has been rarely seen in the Hudson-river group. (State Collection.) 176 PALEONTOLOGY OF NEW-YORK. 226. 14. PLEUROTOMARIA INDENTA ( n. sp.) . Pi.. XXXVIII. Fig. 2 a. Pleurotomaria. Emmons, Geol. Report, 1S42, pag. 39C, fig. 5. Obliquely depressed conical ; spire short, acute ; volutions about three, rapidly enlarging towards the aperture ; the last one, composing the greater part of the shell, is ventricose, biangulated above and rounded below ; angles subnodulose, with indentations between the two and below the lower one ; aperture rounded or transversely broad oval ; surface marked by fine stria;. This species usually occurs in the form of casts of the interior, scarcely preserving any remains of the surface markings. It is readily distinguished by its small acute spire above the last volution, which is distinctly nodulose on the two angles. In this character, it differs from any other in the Trenton limestone. Position and locality. This species is known only in the black limestone at Watertown, being the lower portion of the rock at this place. (State Collection.) 227. 15. PLEUROTOMARIA AMBIGUA (n. *;?.). Pl. XXXVIII. Figs. 3 a, b. Depressed conical, width about equal the height ; spire short, obtuse ; volutions few (three or four), rapidly increasing towards the aperture, subangular, ventricose; the last volution distinctly bicarinate on the outer edge, upper ones with a single carination near the lower side ; suture canaliculated ; aperture subquadrate, with the angles rounded above and expanding below ; umbilicus small, scarcely distinct. This species resemljles in many respects the Pleurotomaria umbilicata, but differs in some important particulars. The spire is higher, each volution being less compressed vertically ; the space between the two marginal angles of the volution is less, and these angles less prominent. The umbilicus is scarcely distinct, and the aperture is less extended transversely, and angulated below, approaching in this respect to Muhchisonia. I have but a single specimen sufficiently perfect to figure, and this one is somewhat distorted from pressure, and tlic aperture imperfect. Fig. 3 a. View of the back of the spiri>. Fig. 3 b. Front of the same, showing tlie apeiturc. Position and locality. In the higher shaly limestone at Adaius, Jefferson county, asso- ciated with the preceding species. (State Collection.) TRENTON LIMESTONE. 177 228. 16. PLEUROTOMARIA PERCARINATA (n. s/).). Pi.. XXXVnr. Fig. 1. Somewhat obtusely conical, vontricose ; spire short, ohtiise ; volutions three or four, rounded, marked by numerous spiral carinee, which are crossed by vertical or undulating striae ; aperture not distinclly visible, but apparently it is broadly oval or rounded ; umbilicus none. This species is readily distinguished from all tlie others known in this rock, by the numerous spiral elevated ridges or carina; which mark tiie surface. It approaches very nearly in character to the Pleurotomaria hilix of Conrad {Joxir. Jlcad. J\~at. Sciences, Vol. viii. pag. 211, pi. 16, fig. 10); but differs from that shell in being more ventricose, and in the volutions being rounded above, while in that species they are flattened, and abruptly contracted below, giving it a more trochiform aspect. This species and the preceding one differ from Pleurotomaria in the form of the aperture, and approach in this respect to Murchisonia. Position and locality. In the compact blue limestone, upper part of the Trenton limestone. Middleville. , , . 229. 6. MURCHISONIA BICINCTA. Pl. XXXVIII. Figs. 5a-h. Compare Pleurotomaria angtilata, Sowerbt in Sil. Researches, pag. 641, pl. 21, fig. 20. Obliquely subconical ; spire elevated, acute ; volutions four or five, angular, rapidly enlarging towards the aperture ; last one ventricose below, tricarinatc, the lower carina hidden by the suture of the next volution at tlie upper inner angle of the aperture ; central carina on the outer angle of the volution, margined on either side by a sharp elevated line, with a narrow groove between, producing a double spiral band ; aperture oblong, angulated below ; surface marked by fine sharp striae, which bend gently backw^ards, and are but slightly undulated in passing the first carina, from whence they turn more suddenly backwards to the mesial band, making an abrupt retral angle, and then bending forwards below, pass in a vertical direction to the suture. In the last volution, the striw pass vertically to the lower slight carina which corresponds with the suture in the other volutions, and from thence bend slightly backwards, curving into the umbilicus. The minute description here given will be found perfectly applicable to entire and un- worn specimens ; but it is often found in fragments and casts, with the surface markings more or less obliterated. The doui)le spiral band becomes obsolete, and only a single ridge is manifest ; the lower carina on the last volution is not visible in casts, and there is but an obscure indication of the upper one. The entire casts, therefore, present scarcely more than the single marginal angle, indicating the direction of the mesial band, and, in this respect, correspond with P. migvlafa cited above ; Inu tlie volutions in our shell are more ventricose. I Pai,.e()NT(ii.ogy.| 23 178 PALEONTOLOGY OF NEW-YORK. Fig. 5 a. Front view of a nearly perfect specimen, showing the form of the aperture, b. Back view. Fig. 5 c. Front view of a specimen with the last volution broken off behind the aperture, giving it a different form. Fig. 5 d. View of an imperfect specimen, showing the direction of the striae. Fig. 5 e. An enlarged view of the same. Fig. 5 f. A smooth cast from crystalhne limestone, scarcely preserving the upper carination in an obscure angle. These specimens are of the ordinary size of the shell in most localities. Fig. 5 g. View of a large imperfect specimen, still preserving the strice upon the surface. This specimen preserves the same form and proportions as the others figured ; but al- though retaining the shell, it does not present the double mesial band, a single obtuse carina being all that is visible. The sharp lines on either side have doubtless been obliterated with- out removing the vertical striae. Fig. 5 A. A portion of the same enlarged. Position and locality. This species occurs more frequently in the lower shaly portions of the Trenton limestone at Mitldleville. It is found occasionally in the higher crystalline part of the same rock at that place. The cast fig. 5 _/ is from the higher part of the same rock at Turin in Lewis county. The larger specimen 5 g is from the compact lower part of the rock at Watertown. (State Collection.) 230. 7. MURCHISONIA TRICARINATA (w. 5j5.). Pl. XXXVIII. Figs. 6 a, b, c. Subfusiform ; spire elongated, acute ; volutions five or more, gradually expanding below, tricarinate, the central carina more prominent than the other two ; aperture suboval, acutely extended below ; surface marked by sharp prominent striae, which are distinctly undulated in passing over the central carina ; umbilicus none. This species somewhat resembles the last, but the spire is more extended and gradually enlarging below ; the central carina is not margined by two smaller ones, and both the carintE and striaj are stronger and more distinctly elevated above the surface. The form of the aperture, so far as can be seen, is more distinctly oval, and not so straight upon the pillar lip. The shejl is somewhat distorted by pressure, and therefore cannot be perfectly represented. Fig. 6 a. View of the back of the shell. Fig. G b. Front view, showing the aperture, which is imperfect on the outer side. Fig. 6 c. This fragment belongs apparently to the same species, but the striae are much better preserved, and the carinte sharply projecting. The striae between the suture and upper carina are directly vertical ; between the first and second carinas they bend backwards, making an acute retral angle on the mesial carina, below which they again turn forwards, and, in passing the lower angle, bend backwards. These characters are clearly distinct from cither of the other species described ia this place. Position and locality. This species occurs at Mineral Point ( Wisconsin) , associated with Pleurotomaria vmbiiicnta and several other Trenton limestone fossils. (Cabinet of Mr. Conrad.) TRENTON LIMESTONE. 179 231. 8. MURCHISONIA PERANGULATA, var. A. Pl. XXXVIII. Figs. 7 a, b. Subfusiform ; spire olongatcd, direct, apex sharp ; volutions six or more, close, angular, not ventricose, gradually enlarging below ; mesial angle very prominent, appressed above and below ; mesial band double, as in M. bicincta ; surface marked by distinct vertical striae, which make an abrupt retral angle on the mesial band ; aperture not visible. This species resembles the M. bicincta in its surface markings, but the volutions are more numerous, and enlarge much more gradually below ; it is also less ventricose, and the upper carina of each volution is nearer the suture. It will probably prove identical with M. perangulata of the Birdseye limestone, which differs only in the absence of the upper carina, which is distinct in this one. Fig. 7 a. Back of the spire, showing si.t volutions Fig. 7 b. A portion of the surface, with the striae enlarged. Position and locality. This species occurs, with M. bicincta, in the lower shaly layers at Middleville. -. •. , 232. 9. MURCHISONIA UNIANGULATA (rt. 4;;.). , ' . . Pl. XXXVIII. Fig. s. Fusiform ; spire elongated, rapidly ascending, acute ; volutions about five, angular, the last one ventricose below ; aperture oval, extended below ; surface marked by a single carina upon the centre of the volutions, whicli are crossed by vertical stria; bending back- wards upon the carina. This species has the form of the last one, but the volutions ascend more rapidly, and there is but a single carination upon the centre of the volution. The latter character dis- tinguishes it from the other species, which all have a smaller carina near the upper marjin of the volution ; and the last whorl has one below the centre, corresponding to the sutural line, which is not seen in the present species. Position and locality. This species occurs with the preceding at Middleville. 233. 10. MURCHISONIA BELLICINCTA ( n. sp.). Pl. XXXIX. Figs. 1 a, b, c, d, e. Compare Turritella cingulata. Hisinger, 1S37, Leth. Suecica, pag. 39, pl. 12, fig. 6. Pleurotomaria cingulata. Von Buch, 1840, Beitr. zur Geol. Russland, p. 116. Murchisonia cingulata. D'Anchiac & Verneuil, Bull, tie la Soc. gfol. de France, Vol. xii. p. 459. — — MuRCHisoN & Verneuil, Pal. Russia, &c. 1S45, pag. 339, pl. 22, fig. 1 a, b. Pleurotomaria. Emmons, Geol. Report, 1S4'2, pag. 390, fig. U. Elongated ; spire composed of eight or more volutions, which are regularly convex, and somewhat rapidly enlarging from the apex ; volutions moderately oblique, marked upon the centre by a flat spiral band, which is margined by slight sharp elevations ; striae bending 23* 180 PALEONTOLOGY OF NEW-YORK. backwards from the sulure to the mesial band, upon whicli they make an abrupt curve forwards ; aperture rounded, extending below, with the pillar lip nearly straight. This is a large and beautiful species, known by its moderately ascending spire and re- gularly convex or ventricose whorls, which render it readily distinguishable, in its usual condition, as casts of the interior. The mesial band divides the volution almost equally, producing no appreciable elevation except at the sharp marginal carina ; and where these are worn down, as they sometimes are, the volutions preserve their equal convexity. The figure of Hisingee (6 a) corresponds very closely with our shell in form ; but the mesial band is much below the centre of each volution, while ours is central. The cast 6 b is too slender, and does not correspond with our species. The figure of M. de Verneuil is also too slender to correspond with our species, and the mesial band produces a carina, which is not a feature of the American fossil. The specimen figured by Hisinger is from the more recent limestone of the Transition period ; and those in the Palteontology of Russia and the Ural Mountains, are regarded as belonging to the Upper Silurian strata. The united testimony of these authors induces me to regard our species as distinct, belonging to the older Silurian limestone, and never known above the Hudson-river group. In the western strata of the same age, there is another more slender species, with obtusely carinated volutions ; but I have never seen the outer smface of the shell. Fig, 1 a. A small imperfect specimen, preserving the strice and mesial band in a very perfect manner. Fig. 1 b. A specimen with the striae partially removed, showing the extension of the aperture below. Y\g. 1 c. A cast, showing the form of the aperture, which is nearly entire. Fig. 1 d. A fragment of a larger specimen, preserving the striae and mesial band. Fig. 1 e. Cast of a larger specimen, the lower volutions broken off Position and locality. This shell is widely distributed, and is very common in the form of casts. It is more abundant in the higlier part of the limestone at Watertown than else- where, but is occasionally found in the lower strata at Middleville. It is likewise found at Trenton Falls, Herkimer, Turin, and other places. ( State Collection ; Cabinet of the Albany Institute.) 234. 11. MURCHISONIA SUBFUSIFORMIS ( «. s^.). Pl. XXXIX. Figs. 2 a, b. Fusiform, elongated ; spire rapidly ascending ; volutions about six or more, flattened, lower one large and ventricose ; aperture oval, acutely extended below ; surface! All the specimens discovered are casts, whicli preserve no remains of external markings. This species is readily distinguished from the last, by the greater obliquity of the volutions, which are flattened, and never present the regularly convex outline of that species. These features are preserved in tiie figure, and will generally be found sufiicient to identify the species. Fig 2 a. View of the back of the spire ; the ape.v imperfect. Fig. 2 b. View, showing, imperfectly, the form of the aperture. TRENTON LIMESTONE. 181 Position and locality. In the higher shaly part of the limestone at Adams, Jefferson county, and Turin, Lewis county. 235. 12. MURCHISONIA VITTATA (w. s;j.). Pl. XXXIX, Figs. 3 a, b. Elongated, fusiform, slender ; volutions oblique, scarcely vcntricose, last one moderately expanded ; suture apparently banded ; aperture extremely elongated. This species has the volutions as oblique as the preceding, and differs principally in the less expansion of the lower one, and the more elongated aperture. The suture appears to be banded, but the single specimen seen is a cast, and this character is somewhat obscure. In general characters, the two last more nearly resemble Loxonema than Murchisonia ; but never having seen the former genus well characterized in the Lower Silurian strata, I am unwilling to admit it upon the evidence of a cast alone. Fig. 3 a. View of the back of the spire. . Fig. 3 6. A partial front view, showing a part of the aperture. Position and locality. In the higher shaly layers of the limestone at Adams, Jefferson county. ^ ,/ .. 236. 13. MURCHISONIA GRACILIS (71. *;;.). Pl. XXXIX. Figs. 4 a, J, c. "" ' Slender, elongated ; volutions not less than ten, ventricose, subangulated on the middle, very gradually increasing in size from the apex towards the aperture ; surface marked by a carinal band upon the centre of the volution, with curving striis above and below. This is the most slender species known in the rock. It is quite distinct from either of the preceding, in the gradual enlarging of the volutions, and its uniformly small size. The centre of the volutions is distinctly marked by an obtuse carina, giving them a subangular character quite different from the M. hellicincta. Casts of the shell are entirely free from the angular carina. All the specimens seen in the limestone of New- York are of the size of those figured, and preserve, but imperfectly, the shell. It is quite similar to, and perhaps identical with, the slender species found in western localities, but is entirely distinct from M. angusta of the Birdseye limestone. ■ . Fig. 4 a. Fragment showing six volutions. Fig. 4 b. Another fragment, showing one of the lower volutions partially covered by the shelL Fig. 4 c. A small fragment, on which the shell is partially preserved. Position and locality. In the crystalline portions of the Trenton limestone at Watertown and Middleville in New- York, at Carlisle in Pennsylvania, and also in the lower shaly beds at Middleville. ig2 paleontology of new-york. Genus SUBULITES (Conrad). Character. " Subulate ; volutions wide, with a very oblique suture ; aperture approaching that of Terebra." " The exact form of the aperture is unknown, the base being imperfect." The above description of this genus is copied from Mr. Conrad's manuscript notes. The specimen figured ( PI. XXXIX. fig. 5 a) , is the original one on which the genus has been founded. 237. 1. SUBULITES ELONGATA. Pl. XXXIX. Figs. 5 a, b, c. Subulites elongata, Conrad in MS. Emmons, Geol. Report, 1S42, pag. 392, fig. 3. Elongated, subfusiform or subulate ; spire rapidly ascending to an acute point ; volutions six or more, flattened ; suture banded ; aperture longitudinally extended, narrow, contracted posteriorly ; surface smooth 1 This remarkable species is easily distinguished by its elongated fusiform shape, and flattened volutions which are very oblique. The last volution is extremely elongated, con- tracting gradually below the centre, and terminating in an acute point. The aperture is narrow posteriorly, gradually enlarging to the centre, and contracting to the anterior extremity. In its usual condition, as casts of the interior, the banded suture is not observed ; but in a single specimen from Middleville, and another from Mineral Point (Wisconsin), the shell is partially preserved, and the suture distinctly banded. In both these specimens there are no visible surface markings, but these may have been obliterated by maceration. Fig. 5 a. Imperfect cast of a large specimen, showing a part of the aperture. Fig. 5 b. A specimen preserving a portion of the shell, and showing the great length of the last volution and aperture. Fig. 5 e. A fragment preserving the shell, and showing more distinctly the banded suture. Position and locality. This species is not unfrequent in the higher crystalline portions of the limestone at Watertown. It is extremely rare in other localities, and I have seen but two specimens from Middleville and one from Wisconsin, showing that it has a wide geographical range. {Slatc Collection, from Dr. Crawe.) TRENTON LIMESTONE. 183 Genus C A R IN A R 0 P S I S. [Carinaria, and On^is; from its resemblance to Carinaria.] Character. Syinmetrical, subconical, pntclliform, subanjrulatetl or rarinatcd on the dorsal line ; apex incurved or convolute ; aperture oval, narrowed posteriorly. There are two or three species of shells having the characters here given. They arc usually associated in tlie rock with the Bellerophon bilohatus, and are rarely seen in any other situation. 238. 1. CARINAROPSIS CARINATA (n. sp.). Pl. XL. Figs. 1 a, b, c. Depressed conical ; apex incurved ; aperture broadly expanded, with a narrow sinus in the posterior dorsal margin, from which a strong dorsal carina extends to the apex ; surface concentrically striated. This species is remarkable for the broadly expanded aperture and sudden contraction towards the apex, which is acutely pointed and incurved. y. Figs. 1 ft, b. Lateral and dorsal views. ' ' Fig. 1 c. Lateral view of another specimen, showing a more elevated carina. Position and locality. In the dark compact limestone at MiddleviUe and Trenton Falls, associated with the Bellerophon hilobatus. 239. 2. CARINAROPSIS PATELLIFORMIS (m. si>.). ' Pl. XL. Figs. 2 a,b. Obliquely subconical, patelliform, the apex incurved and extended in a line with or beyond the margin, obtusely carinated upon the dorsal line ; aperture broadly oval, slightly narrowed posteriorly ; surface marked l)y fine concentric suhlani(>lliform strise. This species resembles in form the recent Capulus ; but the structure of the shell is quite different, being, in this respect, closely allied to the Bellerophon. There are one or two other species in the Hudson-river group, and a single more elevated one in the Trenton limestone, which has not been satisfactorily determined. Fig. 2 ft. Dorsal view. E'ig. 2 b. Lateral view of the same specimen. This one and the preceding species are arranged in this connection, both from similarity f- in the structure of the shell to Bellerophon^ and from an analogy in the form of C. carinata. Position and locality. In the compact finegrained limestone, with the preceding species, at MiddleviUe. 184 PALEONTOLOGY OF NEW-YORK. 240. 1. BELLEROPHON BILOBATUS. Pl. XL. Figs. 3 a, b, c, d, Bellerophon bilobatus. Sowerby in Sil. Researches, 1S39, pag. 043, pl. 19, 6g. 13. — — Emmons, Geol. Report, 1842, pag. 392, fig. 6. Involute, subglobose ; height and widtli about equal ; aperture bilobate, large, sub- reniform ; .surface marked by fine strisc, which, ascending from the umliilicus, form a broad arch on the side of the shell, and, bending downwards, meet in an abrupt curve on the dorsal line. The form of this shell can be readily understood from the two figures, which are of a full grown individual. The arching of the striae upon the dorsal line corresponds with the sinus in the aperture. The greater number of individuals of this species are smaller than the one figured. This species is doubtless identical with the one described by Sowerby under this name. It is abundant in the Trenton limestone, occurring in almost every locality. It is unknown in the Utica slate and lower part of the Hudson-river group, though in the higher part of the same it is often found, and in some localities is numerous. In the last named situation, it corresponds exactly with specimens in the Caradoc sandstone of Great Britain, its associated fossils being precisely similar. Its occurrence in the Trenton limestone, and its reappearance near the top of the Hudson-river group, show its vertical range to be greater than heretofore supposed. In western localities this fossil is equally abundant, ranging througli the entire extent of strata of the same period. It is there, however, usually destitute of the shell, and much distorted from pressure. Fig'. 3 a. Dorsal view, showing the sinus of the aperture. Fig. 3 b. Lateral view, showing the involution of the whorls. Fig. 3 c, d. Two views of a smaller specimen. Position and locality. In the Trenton limestone at Middleville, Trenton Falls, Herkimer, Turin, Watertown, Glen's Falls, Plaltsl^urgh, and numerous other localities. {State Collection.) TRENTON LIMESTONE. 185 241. 2. BELLEROPIION BILOBATUS, var. ACUTUS. I'l,. XL. Figs. 1 a, b, & f) a, b. Compare Rellcrophon aciUiis, Sowebdy in Sil. Researches, pag. 61'!, pi. I'J, fig. II. Involute, suboibiciilar, compressed, elongated ; last whorl acutely angular ; aperture oblong, .sublriangular ; surAice smooth or finely striated ; umbilicus small. The lenglli of tliis .shell is about once and a half ihe height, and the height twice the breadth. It is more elongated and less orbicular than the figure of 7>. acutus of Sowerby ; it is also less acutely cariuated, particularly at the commencement of the involution. The acutely angular, almost carinated, dorsal margin, contrasts strongly with the prevailing forms of B. bilobatus ; and this deviation does not appear entirely the efifect of pressure, but is an original character of the shell, which, in other important particulars, retains the features of the species. Fig. 4 a, b. Dorsal and lateral view of the specimen. The specimen fig. 5 presents another variety of this species, which is apparently due to pressure. The aperture is broadly expanded, and in form like the characteristic varieties; but the siiell is rapidly compressed below, becoming sharply angular, and even distinctly carinated. The striae are similar to those of the more globose varieties, but meeting m a more acute angle on the dorsal line. These varieties all occur in a similar position in the strata, and in Ihe same localities, and are all doubtless referable to the single species. 242. 3. BELLEROPHON BILOBATUS, var. CORRUGATUS. Pl. XL. Figs. 0 a, b. This shell has the fornr of the B. bilobatus.) with similar surface markings. The dorsal side, below the aperture, is characterized by strong folds which reach half way to the umbilicus. These folds are more or less developed in different individuals, sometimes becoming as distinct as in the one figured. The aperture in such specimens is more angular, and the sinus on the dorsal margin less regularly curved. In other respects there appears to be no essential difference between this fossil, and that marked by simple strire. Both in the specimens having this character, and in those with stria alone, the dorsal margin is sometimes obtusely angular, and in others llattened. The specimen fig. 6 a is in a stone with three others, only one of which shows a slight development of these dorsal folds. Fig. 6 6 is a specimen less distinctly corrugated. This variety of form occurs in the same localities and position as the preceding ; being, however, of comparatively rare occurrence. (Cabinet of Mr. Moore, Trenton Falls.) [Palaeontology.] 24 186 PALAEONTOLOGY OF NEW-YORK. 243. 3. BUCANIA EXPANSA ( n. sp.). Pl. XL. Figs. 1 a,bc,d. Convoluie, trumpet-shaped ; volutions three or four, subangular, the last one elongated, rapidly enlarg-ing and abruptly expanded at the aperture ; aperture broadly semicircular or sublunalc, with a sinus at the dorsal side ; dorsal line obtusely carinated ; section of the last volution, below the apertine, subtriangular ; of the inner volutions, subelliptical, with the extremities obtusely angular ; original surface striated. Specimen a cast. This shell is not unlike Bellerophon cornuarietis ( Sowerby, Min. Conchology, tab. 469, fig. 2 ) ; but tlie volutions in that species are represented as not contiguous. The species under consideration differs from either of the two preceding in a very obvious manner. Tiie broadly expanded aperture and oljtuse carina of tlie last volution are prominent features ; and in fragments, the subtriangular form of sections of the last volution are often sufficient to enalile ns to identify the species. The strongly marked carina commences at tlie base of the last volution, and continues to the aperture. The volutions are closely pressed against each other, the convex dorsal side producing a corresponding depression on the ventral side of the contiguous volution. Fig. 7 a. View of the back of the shell, showing- the strong carina, expanded aperture, and sinus on the dorsal margin, b. Lateral view of the same. Fig. 7 c. Transverse section of the last volution, below the aperture. Fig. 7 d, e. Lateral and front view of another specimen, from which the expanded portion of the aper- ture is broken off, and showing also a little deviation in form. Position and locality. In the lower irregularly bedded portions of the Trenton limestone, and in the strata resting on the Black-river limestone, at Watertown, Jefferson county. {State Collection.) 244. 4. BUCANIA BIDORSATA («. s;;.). Pl. XL. Fig.s. 8 o, 6, c, d, e,f, g. Convolute, subglobose, with a deep umbilicus ; volutions about three, the last one extended and somewhat straight, gradually enlarging and more abruj^tly expanding to- wards tlie aperture ; dorsal margin witii a double or grooved carina, on the centre of which is a narrow elevated line ; on each side of the dorsal band is a broad groove or depression, and an obtusely angular ridge, the latter being half way l)elweeii the centre and margin of tlie shell ; surface ornamented by transverse fililorm striie, wliicli, receding from the umbilicu.s, bend abruptly backwards near the centre, making a more gentle curve on the dorsal band ; aperture sublunate. In young specimens, the carinal btiiid is very consjiicuous, willi a narrow elevated central line. The lateral carinje or ridges scarcely all'ect tlie directijii of the stria> ; the de])ressions on the outside of these ;ue less conspicuous lliaii on the inner side. In this respect, however, there is some variation in specimens from dilferent localities. In casts of ' TRENTON LIMESTONE. . 187 the shell, the detail of the surface markings is partially lost, ami a broad dorsal carina is sometimes all that is observaliie ; I lie marginal carina; are often faintly distinguishable by a slight depression on either side. A section below tjie a])ertnre presents an extremely excentric ellipse, which is depressed on the ventral side by tiic convexity of the contiguous volution. Fig. 8 a. Dorsal view of a small specimen, preserving a portion of the shell. Fig. 8 h. View of the aperture, which is very imperfect. Fig. 8 c. A fragment, showing the carinas and dorsal band very distinctly, d. The same enlarged. Fig. 8 e. Cast of a larger specimen, imperfect towards the aperture, and showing only the broad dorsal carina. /. Lateral view of the same, showing the umbilicus. Fig. 8 g. Section of the last volution below the aperture. Position and locality. This species occurs in the lower shaly portions of the rock at Middleville, and in the compact lower layers of the same rock, immediately above the Black-river limestone, at Watertown, Jefferson county. (State Collection.) 245. 5. BUCANIA PUNCTIFRONS. Pl. XL. A. Figs. 1 a, b, e, d, e. Bellerophon punctifrona. Emmons, Geol. Report, 1842, pag. 392, fig. 5. Convolute, suborbicular ; volutions about three, gradually enlarging, rounded upon the back ; dorsal line marked by an abrupt narrow carinal band ; sides of the volutions abruptly rounded, suddenly depressed into a broad deep umbilicus, which reveals the inner volutions ; surface marked by rounded or rhomboidal punctures, which are regularly arranged in lines in two directions ; carinal band marked by close curved striae ; the last volution is little extended, and abruptly expanded near the aperture, which has a shallow sinus on the dorsal margin. This beautiful species is readily distinguished by tiie peculiarly ornamented surface. The dorsal band is sometimes abruptly elevated, and at other times even with the surface of the shell, and marked by curved striae. In a single specimen I have detected lateral longitudinal ridges, which interrupt (he regularity of the surface markings ; but these appear to be accidental. Fig. 1 a. Dorsal view of a small specimen, h. Lateral view, showing the umbilicus. Fig. 1 c. Dorsal view of a larger specimen, showing the elevated carinal band, which docs not rise above the surface on the lower part of the shell. Fig. 1 d. Lateral view of another specimen, showing the side of the shell, which is obtusely angular with obscure lono-itudinal ridafes. Fig. 1 e. A portion of the surface enlarged. Position and locality. This species occurs in the higher crystalline portions of the rock a( Middleville and Watertown. (State Coileetion.) 24* 188 PALEONTOLOGY OF NEW-YORK. 246. 1. CYRTOLITES COMPRESSUS. Pl. XL. A. Figs. 2 a, b, c, d, e,f. Reference Pliragmolites cmnpressus, Conrad, Ann. Geol. Report, 1838, p. 110. Discoidal ; volutions scarcely contiguous, very gradually enlarging, rounded on the sides, sharply and profoundly carinated on the dorsal margin ; greatest diameter of the volutions from the dorsal to the ventral side ; aperture scarcely expanded ; surface ornamented by transverse, zigzag or abruptly undulating, elevated, subinibricating lamellae, and finer transverse and longitudinal stria;. This very beautiful and unique species is readily distinguished by the undulating elevated lamelhT, which mark the surface at more or less distant intervals. Every forward bend of these lines is accompanied by a slight depression behind it, and every retral bend shows a broad slightly elevated ridge behind. This character is not, however, always conspicuous, but sometimes gives a nodulose appearance to the shell. The sharp dorsal carina fills a narrow groove in the ventral side of the inner volutions, the sides of which are not other- wise in contact. The Genus Phragmolites of Conrad ( ut supra) was founded upon this species, on the supposition that it was septate internally, which is not true, as I have had opportunities of examining the interior. The undulated lines are merely superficial, and rarely at equal distances from each other in diflferent shells. The Genus Cyrtolites was organized by Mr. Conrad for the reception of a species from the Hudson-river shales : that species, like the present, is profoundly carinated ; the carina filling a groove in the ventral side of the volutions, which are scarcely contiguous. The surface in both is peculiarly ornamented and subnodulose, the volutions having a greater longitudinal than transverse diameter. I have therefore removed this species from Phragmolites, and placed it imder Cyrtolites, the typical species of which is C. ornatus. It maybe remarked, in this place, that these species differ in essential characters from any of the BucANiiE, to which they are in some respects allied. Fig. 2 a. Lateral view of a specimen, having the sinuous lamollse at the ordinary distance asunder. Fig. 2 b. Dorsal view of the same. Fig. 2 c. Lateral view of a specimen, where the elevated lamellas are more distant. Fig. 2 d. Lateral view of another, showing the lamellas closely arranged. Fig. 2 e. A cast, which is smooth, with the exception of the elevated carina. Fig. 2/ A portion of the surface enlarged, showing the finer transverse and longitudinal striffi, aiid the subnodulose appearance of the surface. Position and locality. This species occurs, in its greatest perfection, in the lower shaly strata of the Trenton limestone at Middleville. It is found, also, in the higher crystalline pnitof the rock at the same place; and, in the form of casts, in the higher crystalline portions of the same rock at Watertown. TUENTON LIMESTONE. 189 247. 2. CYRTOLITES TRENTONENSIS. Pl. XL. A. Figs. 3 a, b, c, d ; ami Pl. XLI. Vi'fii. 1 a, b, c. CyrtoUtes trcntoncnsin. Conrad, Jour. Acad. Nat. Science, 18-12, Vol. viii, pag. 270, pi. 17, fig. 4. Compai-e Eeciilioiiiplialus minor, Portlock, Gcol. Rep. Londonderry, 1813, pag. 412, pi. 30, figs. 11 & 12. Shell slender, angular, gradually curving and tapering to an acute point, making rather less than an entire volution ; dorsal and ventral margins angulated or subcarinated ; lower side distinctly angulated ; upper side less prominently angulated, and suddenly contracted on the inner margin ; section subquadrangular ; aperture scarcely expanded ; surface marked by obliquely transverse striaj. This peculiar little shell has the appearance of a claw or talon, making from two thirds to nearly an entire volution. It bears considerable resemblance to Ecculiomphalns minor, cited above. It differs in some important characters from the typical species of CyrtoUtes of Conrad, which he describes, however, as being in form like Cyrtoceras* It is usually an obscure fossil, occurring as casts of the interior, and destitute of surface markings. Plate XL. A. Fig. 3 a, b. View of the upper surface of two individuals. Fig. 3 c. Lower surface of the same. Fig. 3 d. Dorsal view. Plate XLI. Fig. 1 a. Lower surface of an imperfect specimen. .- Fig. 1 b. A portion of the surface strise enlarged. Fig. 1 c. Section of the shell below the aperture; the upper side of the figure being the dorsal margin. Position and locality. In the higher strata of the Trenton limestone at Middleville ; in a lower position, in the same rock, on tlic Moliawk valley, associated with Isotelus, fyc; and in the same rock at Carlisle, Pa. (State Colleclivn ; Cahinet of Mr. Co.vRAD.) ' Mr. Morris (Catalogue of British Fossils, p. 21G) regards CyrtoUtes as identical with Eccnliomphalvs, and remarks that the former should be retained. Although unwilling to allow tlie present and succeeding species to remain under CyrtoUtes, I have so arranged them for the present; believing that the Genus EcculiompUulus, or some other, will include those forms like the one under consideration. 190 PAL^ONTOLOGV OF NEW-YORK. 248. 3. CYRTOLITES FILOSUM. Pl. XLI. Figs, 3 a,b Cyrtoceras [Cyrtolites 7 '] filosum, Conrad in MS. Emmons, Geol. Report, 1S42, pag. 372, fig. 4. Shell forming a nearly straight, gradually tapering, rounded tube in its upper part, curving towards the extremity, and making little more than half a volution ; surface marked by fine transverse lamellose striae, which bend downwards in an arch on the back of the shell ; section circular. This species has been given by Dr. Emmons as a Cyrtoceras, but inadvertently, as he considers it destitute of septa. The specimen figured is the only one known, and it is imperfect towards the aperture. The shell is removed and broken in several places, but reveals no evidence of septa, though the surface markings indicate that it is a cephalopod. I am, therefore, still uncertain as to the true place of this species. Fig. 3 a. Lateral view of the specimen imbedded in stone, the apex being concealed. Fig. 3 b. View of the dorsal side of a small portion of the shell, showing the arched strias. Position and locality. This species has been seen only in the higher crystalline part of the rock at Watertown, Jefferson county. (State Collection.) • I have seen fragments of one or two other species of analogous form, where there was no evidence of septa, but have hesitated to arrange them in this association, hoping that that some fortunate discovery would reveal their true character. I am the more doubtful in this matter regarding forms like the Cyrtoceras, since I have learned that the tubes of the true Orthoceras do exist without any evidence of a septate character, while other specimens, precisely similar in every other respect, are provided with septa. The absence of septa, in such cases, does not always appear due to accidental destruction, but to their non-development ; and perhaps the same may be true in regard to those forms like Cyrtoceras. TRENTON LIMESTONE. 191 CEPHALOPODA OF THE TRENTON LIMESTONE. Plates XL. A. (in part), & XLI. - LVIII. The great abundance of a single family of this order, the Orthocerata, constitutes a peculiar feature of the strata of this period. Here they attain their maximum development, and at no subsequent period during the palaeozoic era do they appear in any thing like equal abundance. At the base of this reck, in the Black-river limestone, I have already shown (page 52) that there was a remarkal)le development of individuals of this family, though comprising a few species only. During the present period, we find a large number of species, many of which are exceedingly abundant and widely distributed ; while others, so far as known, are of rare occurrence. Near the base of the Trenton limestone, where I have had good opportunities of seeing the strata, the Orthoceras is very rare ; while the few species of Cyrtoceras, known in the rock, seem almost confined to that position. As we ascend in the strata, specimens of Orthoceras are occasionally found, but never abundantly in the lower half of the deposit. The Trocholites, which differs from Lituites principally in the position of the siphuncle, is abundant in the central part of the rock, occupying but a small tiiickness, and mostly confined to a few localities in the vicinity of Middleville and Trenton Falls. At about the same point we find the Orthocerata increasing in mmibers, and, in succeeding beds, they occur in such profusion as to lie in contact with each other, imbedded in myriads. In the highest beds of this limestone, in many places they have nearly disappeared, though in some portions of the succeeding slate they are again abundant. It is not a little remarkable, that notwithstanding the abundance of this genus of chambered shells, so few species of other cephalopods siiould occur in the same strata. The two species of Lituites known in the Black-river limestone, are not known in this position ; the only representative of the family, known, being a single species, besides the Trocholites just noticed. From the immense profusion of the Orthocerata, which can scarcely be overstated, we should expect to find specimens so well preserved that the entire form and structure could be ascertained ; but this is not true. Almost all, and indeed every specimen found, is more or less imperfect ; whether young or old, of large or small species, they have suffered injury, in a greater or less degree, before being imbedded in the sediment whicii now envelops them. This condition of the specimens, many of which are small, we are not prepared to find, if we regard them as internal shells, where the muscular body of the enclosing animal might have protected them till they were surrounded with the soft cal- careous mud. In their present condition, however, we are compelled to depend upon frag- ments, and to indicate the specific differences by the surface marking wiien preserved ; or, in its absence, by the form of the tube, distance of the septa, and position of the siphuncle. In another place, I shall endeavor to illustrate the hal>its of tiic Orthocerata more in detail ; showing their structure, mode of development, and other peculiarities derived from the examination of a vast number of specimens obtained from tiie Trenton and Black-river limestones. 192 PALiEONTOLOGY OF NEW-YORK. 249. 1. TROCHOLITES AMMONIUS. Pl. XL. A. Figs. ia-k. Trocholites ammonius. Conrad, Ann. Geol. Rppoit, 1S3S, p. U9. See also Generic description of Trocholites revised, in Jour. Acad. Nat, Science, 1812, Vol. viii, p. 274. — Emmons, Geol. Report, 1842, pag. 372, fig. 4. Compare Lituites cornuarittis, Sowerby in Sil. Researches, 1839, pag. 643, pi. 20, f. 20, & lb. pi. 22, f. 18. — PoRTLocK, Geol. Rep. Londonderry, 1843, pag. 382, pi. 28 B, fig. 7 a, b. — Verneuil, Pal. Russia and Ur. Mountains, 1845, pag. 359, pi. 25, fig. 7 a,b, — odini. Id. lb. pag. 301, pi. 25, fig. 8. Clymenia odini? Eichwald, 1840. Discoidal ; volutions in the same plane, about four, rounded, slightly concave on the ventral side, gradually enlarging in size towards the aperture, which is slightly expanded ; surface marked by lamellose irregular and oblique transverse stria? or ridges, between and upon which are finer lamellose striffi, covering the outer surface, and giving it a peculiar textural or netted appearance ; strife meeting in an arch upon the back ; septa direct, or slightly undulated on the dorsal side ; outer chamber large ; siphuncle ventral. This is a very beautiful and interesting shell, and its usual appearance is very correctly represented in the figures. In examining a large number of specimens, I have never found one where the last volution extended in a direct line. I have been inclined to regard our species as identical with Lituites cornuarietis of Sowerby ; but if the one figured by de Verneuil is identical, our species presents some important variations. The strife meet in an arch upon the back, and not in an acute angle forming a V as in the latter. In a single injured specimen, however, I have detected a few of the strise near the aperture, meeting in this manner upon the back, while the others present the usual appearance. The peculiar character of the surface is produced by the numerous crowded edges of lamellee, which, in perfect specimens, are somewhat regularly undulating. When the shell is partially exfoliated, the textural character of the surface is destroyed, and it is only marked by fine oblique striffi. The stronger striaj are very variable, being soinetimes so prominent as to deserve the name of ridges, and at other times are only slight undulations ; while in many instances they are not at all developed, and the smface is marked only by the finer lamellose striae. Upon a careful examination of the figures and descriptions o{ Lituites odini of Verneuil {Clymenia of Eichwald ) , I am satisfied that our species is closely allied, if not identical with that one, and that it is qtiite distinct from the L. cornuarietis of Russia. The striiE of L. odini are arcuate upon the back, precisely as in our specimens ; the septa are likewise slightly undulating or bent towards the aperture on the back, particularly those of the inner volutions ; and the whole aspect of the shell is decidedly like the New- York specimens, •where the outer surface is exfoliated. In the Russian specimen, however, the siphuncle is not represented so close to the ventral side of the volution as it is in our specimens. This may happen in the last volution, where it is produced in a direct line, and less appressed on the ventral side by contact with the inner ones. TRENTON LIMESTONE. 193 There may be some doubt as to tlie propriety of separating this species from Lituites, which has been done principally on account of the ventral position of the siphuncle; since this deviation is not usually regarded as important. M. de Verneuil, speaking of this position of the siphuncle in L. odini, does not consider it as suflicient to found a generic distinction. Fig. 4 a. A small perfect specimen, showing the lamellose striae in great perfection. Fig. 4 fi. A large specimen, preserving the lamellose surface. Fig. 4 c. Dorsal view, showing the archings of the strife upon the back. Fig. i d. A specimen denuded of the shell, showing the septa and deep outer chamber. Fig. 4 e. Section, showing the position of the siphuncle. Fig. if,g. Lateral and dorsal view of a fragment of an inner volution, showing a shght undulation of the septa on the back. Fig. 4 h. Lateral view of a fragment partially denuded of the shell, showing only the oblique transverse ridges. Fig. 4 i. Dorsal view of the same, showing the arching of the stria; upon the back. Fig. 4 k. Section of the same, showing the position of the siphuncle. Position and locality. This shell occupies a central position in the Trenton limestone, being unknown in the lower part, but passing upwards into the Utica slate, where it is of less frequent occurrence. - {State Collection.) 250. 1. CYRTOCERAS LAMELLOSUM ( n. .9/).). Pl. XLI. Figs. 2 a, b, c. Subcylindrical, gradually curving and tapering ; aperture somewhat expanded, and the shell slightly constricted just behind ; septa closely arranged ; surface with transverse undulating squainose lamellae, which are abruptly bent backwards on the dorsal line ; lamellas equidistant with the septa, but not corresponding to them ; spaces between the lamellae marked by fine transverse striae. The form of the entire shell is unknown, the only specimen seen being a fragment : this, however, is well characterized in its surface markings, which resemble in some degree those of the Cyrtolites comprcssus ; but the lamella; are more squamosc, and less abruptly undulating, as well as more closely arranged than is usual in that species. An exfoliation of the sliell on one side exposes the interior, which is clearly septate. Fig. 2 a. Lateral view of the fragment Fig. 2 b. Dorsal view of the same. Fig. 2 c. Magnified portion of the surface. Position and locality. In the lower part of the Trenton limestone at Middlcville. [Palaeontology.] 25 194 PALJEONTOLOGY OF NEW-YORK. 251. 2. CYRTOCERAS ANNULATUM (n. sp.)- Pl. XLI. Figs. 4 a, b, c, il ; and Fig. .5. Gradually curving, expanding towards the aperture ; surface annulated by strong ridges, which, with the intermediate spaces, are marked by fine transverse strife ; siphuncle central ; septa jjlain. This species is readily recognized among all the others, at present known, in this rock, by its elevated annulating ridges and fine striee, in which it is very similar to some of the Ortliocerata. The shell is pretty uniformly curved, gradually enlarging, and more abruptly expanding towards the aperture. It occurs in fragments, a perfect specimen not having been seen. The central position of the siphuncle is a departure from the usual character of Cyrtoceras, and on this account may be regarded as a bent Orthoceras ; but it enlarges more rapidly towards the aperture than ordinary species of that genus, and being constant in its curvature, this may be regarded as its normal form. Fig. 4 ffl. A large fragment, which is a cast, retaining the annulations. Fig. 4 b. A smaller fragment, retaining the shell and transverse strife. Fig. 4 c. Section of the last, showing the siphuncle. . Fig. 4 d. A portion of the surface magnified. Fig. 5. A fragment of the same species, nearer the aperture. Position and locality. In the lower shaly strata at Middleville, and in the higher crystal- line strata of the same rock at Watertown. (State Collection.) 252. 3. CYRTOCERAS MACROSTOMUM. Tl. XLII. Figs. 1 a, 4, c, & 3 a, b. Cyrtoceras marginalis. Conrad, Proc. Acad. Nat. Sciences, 1843, Vol. i, p. 334. Not Cyrtoceras marginahy Phillips, Pal. Fossils, 1841, pag. 115, pl. 4(j, fig. 219. Subconical, slightly incurved, rapidly enlarging from the apex ; outer chamber large, forming about half the length of the fragment ; septa closely arranged ; siphuncle dorsal i section not entirely circular ; surface 1 The fragment measures four inches, the outer chamber occupying one half the length. There are twenty-five septa remaining in the portion preserved. The diameter of the smaller extremity is half an inch ; and of the larger, one inch and seven-eighths, the edge being broken. The septa are interrupted, and slightly bent upwards along the dorsal line, by (he siphuncle. The elliptical form of the section is due to pressure, the natural form being circular. The larger specimen described is from Wisconsin, where it occurs associated with Trenton limestone fossils. Fraginents of the same have been seen in New-York and in Pennsylvania. The fragment 3 c i is probably of the same species, since a careful examination shows that it is not identical with Zed. This specimen is marked by closely arranged lamellose stria?, TRENTON LIMESTONE. 195 which bend abruptly ilownward over the dorsal line, in form like the letter V. The siphuncle is also dorsal. Fig. 1 a. A fragment, showing a partial spction. Fig. 1 A. A large fragment, showing the wide outer chamber. Fig. 1 c. Section of the smaller extremity of tiie last. Fig. 3 a. Dorsal view of a fragment probably identical : the striae in the figure do not bend so abruptly as in the original. Fig. 3 b. Lateral view of the same. Position and locality. In the Trenton limestone at Middlcville ( N. Y.), Carlisle (Pa.), and in light buff-colored limestone of the same age at Mineral Point ( Wisconsin) . ( State Collection ; Cabinet of iMr. Conrad.) 253. 4. CYRTOCERAS CONSTRICTOSTRIATUM (h. s;).). ' - Pl. XLII. Figs. 2 a, b, and 3 c, d. Very gradually curving, and enlarging towards the aperture, which is but little expanded ; septa approximate ; siphuncle dorsal ; surface marked by filiform transverse stria;, which, at intervals, are bent abruptly downwards, or constricted ; section elliptical. This species, from its very slight curvature and gradual tapering, might perhaps be regarded as an Orthoceras ; from which, however, I believe it to be distinct. I have relied mainly on the external markings to characterize the species, but have arranged with the one thus marked, other fragments, which appear to me of the same species, though destitute of the shell. Fig. 3 c. A fragment, showing the surface markings. Fig. 3 d. Section of the same, which does not show the siphuncle. Fig. 2 «. A fragment, showing several of the septa and a part of the outer chamber. Fig. 2 b. Transverse section, somewhat compressed, showing the position of the siphuncle. Position and locality. This species usually occurs in fragments in the lower shaly layers of the Trenton limestone at Middlcville. A single specimen, only, has been found in the upper part of the rock at the same place. 254. 5. CYRTOCERAS MULTICAMERATUxM ( n. sp.). Pl. XLII. Fig. 4. This specimen is a fragment denuded of the shell ; it is somewhat straight above, more abruptly curving below, and gradually tapering. It is remarkable for the close approxima- tion of the septa. The specimen is too obscure and imperfect to be reliable, but is given as clearly showing its distinction from the other species. Position and locality. In the lower shaly beds of the Trenton limestone at Middleville. (State Collection.) 25* 196 PALEONTOLOGY OF NEW-YORK. 255. 6. CYRTOCERAS ARCUATUM ( n. sp.) . Pl. XLII. Figs. 5 a, b, c. Broadly curving, and very gradually tapering ; septa approximate, thin ; section elliiJtical ; siphunde dorsal 1 This species has the appearance of a curved Orthoceras ; but I have seen several fragments of the same, all of which are curved, while I do not know a straight species having the same characters. The specimen figured is compressed, giving the section a very eccentric elliptical form. The siphuncle is obscure, but there is some indication of its existence upon the dorsal margin. Fig. 5 a. Lateral view of the specimen, which is crushed towards the lower extremity. Fig. 5 b. Section of the same. Fig. 5 c. The base of a parasitic coral, or of a crinoid, attached to the fossil. Position and locality. In the lower shaly layers of the Trenton limestone at Middleville. 256. 7. CYRTOCERAS CAMURUM ( n. sp.). Pl. XLII. Fig. 0. This species is somewhat similar in form to the last, but curving more rapidly. The septa are more distant, being once and a half those of the last species. The siphon is dorsal, as shown in some fragments of the same. This species is not rare in the lower strata of the Trenton limestone ; but it is almost always so intermingled with other fossils, that it cannot be separated except in fragments. It is clearly distinct from the other species, though it is at present impossible to designate the important characters of an entire specimen. Position and locality. In the lower strata of this rock at Middleville, in a situation where all the other species of the genus known in the Trenton limestone are found, two only being known in a higher position in the same rock. Genus ONCOCERAS. f Greek, oyxos, a bending or protuberance, and xspa?, a horn ; the central portion of the fossil resembling a flexed and enlarged joint] Character. Tube curved ; aperture constricted ; lower part of the outer chamber, and upper part of the septate portion, ventricose, abruptly contracting towards the apex ; siplnmcle small, dorsal ; septa plane, nearly flat, slightly elevated on the dorsal margin. This genus will probably be found restricted to the lower pala;ozoic strata. TRENTON LIMESTONE. 197 257. 1. ONCOCERAS CONSTRICTUM (n. 5/).). Pl. XLI. Fi^s. ('p a -/, and 7 a, b, c, il. Sliell curving-, vontricose in tiic midcUc, abruptly constricted near the aperture, and rapidly tapering towards tlic apex ; sepia very slightly convex, numerous, approximate, slightly undulating and bending upwards on the dorsal margin ; section ovate, Avith the dorsal side narrower and somewhat obtusely angular ; siphuiicle small, dorsal ; surface striated transversely. The characters here given are those presented by a number of specimens examined, though with some little variation, depending on local circumstances, or the nature of the strata. I have decided to retain all the various forms as one species, though we may yet be able to separate them. This fossil has the form of Phragmoceras, which it resembles in the contraction of the aperture ; while the position of the siphuncle is different, Ijeing dorsal as in Cvrtoceras. It appears sufficiently distinct from the latter to constitute a new genus, allied to Phrag- moceras, and in some respects to Gomphoceras. It is recognized when perfect, not only by the contraction of the aperture, but by the ventricose character of the lower part of the outer chamiMM- and upper part of the sep(atc portion, below which it is again suddenly contracted towards the apex. The base of the shell is often nearly perfect, but the apex is usually destroyed, or extends into a curved prolongation like that represented in 6 /, in which there is no evidence of septa. I have seen this kind of termination in two or three instances, while all the other specimens have been imperfect like 6 d e. The septa are exceedingly thin ; and from the slight convexity, the edges of the chambers in the cast are remarkably angular and sharply defined, presenting an appearance very different from the Cvrtoceras or Orthoceras of the Trenton limestone, and which is sufficient to distinguish the species even in casts of a single chamber. Fig. 6 a. View of the ventral side of an imperfect specimen. Fig. 6 b. Lateral view of the same, showing the sudden contraction below the outer chamber : the aperture is imperfect. Fig. 6 c. Section of the lower extremity, showing the small dorsal siphuncle. Fig. 6 i. A smaller specimen, showing the same form as the last. Fig. 6 e. A shorter and more ventricose specimen. (The transverse lines on the upper half of the figure, indicating septa, are incorrect.) Fig. 6/ The apicial extremity of the fossil. Two or three specimens have been found, with an ap- pendage or termination of this kind. Figs. 7 a, c. Dorsal and lateral views of a fragment, showing the direction of the septa. Figs. 7 b, d. Sections of different specimens, sljowing the position of the siphuncle, and the narrowing of the dorsal side of the shell. Position and locality. This species is comparatively rare in all the localities examined. It occurs at Middleville, in the lower part of the rock ; wliile at Waiorlown a few speci- mens have been seen in the higher part of the same rock, and I have received a specimen from Mr. Joseph Clarke, of Cincinnati, Ohio. (f^tatc Collection.) 198 PALEONTOLOGY OF NEW-YORK, 258. 11. ORTHOCERAS ARCUOLIRATUM (n. s;).). Pl. XLII. Figs. 7 a, b, c. Cameroceras* trentoneiisis (siphuncle), Conrad in MS. Emmons, Geol. Report, pag. 397, fig. 4. Slender, very gradually tapering to an acute point ; surface marked by strong and extremely arching or undulating annulations, and, obscurely, by fine longitudinal striee ; annulations about equalling the spaces between them ; outer chamber and aperture un- known ; section circular ; siphuncle central. The distinguishing features of this species are its slender form and extremely arched annulations, which, in half the circumference, ascend twice the width of the space between each annulation. All the other annulated species have the ridges less arched upon the back. Fig. 7 ffl. A fragment near the apex of the shell. Fig. 7 b. A fragment of larger diameter, showing the convexity of a septum. Fig. 7 c. Transverse section, showing the central position of the siphuncle. Position and locality. This species occurs both in the lower shaly strata of this rock at Middleville, and in the higher crystalline portions of the same rock at Watertown. (State Collection.) 259. 12. ORTHOCERAS TERETIFORME (n. 5;>.). Pl. XLII. Figs. S a, b. Ortlioccralite. Emmons, Geol. Report, 1S42, pag. 306, fig. 3. Robust ; tube strong, somewhat rapidly tapering towards the apex ; outer chamber and aperture unknown ; surface marked by strong, slightly undulating annulations, the centres of which are distant from each other about twice the diameter of the ridges, longitudinally marked by coarse stria3 ; section circular ; septa having a convexity exceeding one third the diameter of the tube ; siphuncle small, central. The specimens of this fossil which have been seen, are imperfect, and have only a portion of the shell remaining, which preserves some strong longitudinal strife without any visible finer markings. It differs from the preceding species in the stronger annulations, which are less undulated than in that species ; the surface markings are also stronger, and the tube enlarges more rapidly towards the aperture. The summit of the lower specimen is covered by the dorsal valve of Orthis testudinaria, which gives an irregular convexity to the outline. • Mr. Conrad {Jour. Acad. J^'at. SH. Philadelphia, 1S43, Vol. viii, p. 207 ) has proposed the generic name of Cameroccras for a species of Ortlioccralite with a large lateral siphuncle, which exhibits strong oblique ridges at the junction of the septa. This specimen is clearly septate within, and is therefore not the siphuncle. (See also Plate Ivi. of this Report.) TRENTON LIMESTONE. 199 Figf. 8 a. Fragments of two specimens connected by the dotted lines. The annulations are represented as too broad. Fig. 8 b. Section showing the position of the siphuncle. Position and locality. This species is only Iviiown to me as occurring in the higher crystalline portion of the limestone at Watertown, Jefferson county. (State Collection.) 260. 13. ORTHOCERAS TEXTILE ( n. sp.). I'L. XLIII. Figs. I a,b. , ' . General figure cylindrical, very gradually tapering, marked by prominent transverse or slightly arching annulations, which are distant about one third the diaineter of the shell ; entire surface marked I)y fine longitudinal and transverse stria;, which are closely arranged, the series being equidi.stant from eacii other, giving the surface the appearance of a woven texture; septa rather deeply concave, distant about one third of liie diameter; section circular; siphuncle'? This fossil bears some resemblance to O. calamitcum, as figured l)y Portlock (Geo/. Rep, Londonderry, pag. 365, pi. 25, fig. \ a,b); but our specimens never present any "strong longitudinal threads or stripes" passing over the annulations, the stria; being uniform in this respect. It also differs essentially from 0. tuhicinella of Sowerby, which we find in our Hamilton group. Fig. 1 a. A fragment of the natural size. Fig. 1 b. A portion of the surface enlarged, to show the stria;. Position and locality. In the lower concretionary beds of the Trenton limestone at Watertown. t' - - 261. 14. ORTHOCERAS BILINEATUM (n. .?/).). Pl. XLIII. Figs. 2 a, i, c, d. Compare Orthoceras calamiteum, Munster, 1S39, heft i, pag. 3G, pl. 17, fig. 5 ; Id. lS-10, heft iii, p. 102. — D'Archiac &. DE Verneuil, 1S42, Trans. Geol. Soc. London, 2d series, Vol. vi, — Portlock, Geol. Rep. Londonderry, 1843, pag. 30'), pl. 25, fig. 1. [p. 346. — — Verneuil, Pal. Russia and the Ural Mountains, 1845, pag. 353, pL 25, fig. 5. General form cylindrical, gradually tapering, marked by slightly arched or undulating rounded annulations distant about two fifths the diameter; surface marked by longitudinal sharp elevated lines, which alternate with finer lines in equal number ; transversely marked by fine scarcely visible striie, which are interrupted by (he longitudinal lines ; section circular ; siphuncle excentric. The two series of longitudinal lines, one being more tlian twice the elevation of the other, are distinguishing features of this fossil. The annulations are more arched on the back 200 PALAEONTOLOGY OF NEW-YOKK. than in the last species, but still rounded. The transverse fine striae, under the magnifier, give a kind of varicose appearance, being closely arranged and slight!)^ arched between the longitudinal ones, following the oblique direction of the annulations. The difference in the size of the longitudinal and transverse lines is a striking peculiarity of the species, rendering it readily distinguishable from the last. I have referred above to the 0. calamiteum of Munstee, which, however, is from the liio-her silurian or devonian rocks, from which circumstance alone it is proper to presume it distinct from this one. The figure of Poetlock corresponds in some degree with our species, but is represented with two or three finer longitudinal strife between the larger ones, while the transverse striee are as strong as the fine longitudinal ones ; in which characters, the one under consideration is quite different. M. de Verneuil has represented the O.calamiteus as destitute of transverse strise ; though tlie one referred to that species by D'Archiac and DE Verneuil, cited above, has transverse stria;. The species under consideration is not only quite distinct from 0. tiibkineUa of Sowerby, Init from all the species in our higher strata, tliough having some resemblance to them. Fig. 2 a, b. View of two individuals, showing the annulations and longitudinal striK. Fig. 2 c. Transverse section of b. Fig. 2 d. Portion of the surface enlarged. Position and locality. In the lower shaly strata of the Trenton limestone at Middleville, Turin and Lowville. A fragment or impression of the saine species has been found at an exposure of the Trenton limestone one mile east of Alban}', which was incorrectly figured on Plate VII. (See page 35). (State Collection.) 262. 15. ORTHOCERAS BILINEATUM, var. a. Pl. XLIII. Figs. 3 a, b, c, d. This variety differs from the typical forms, in the absence of the intermediate finer longitudinal stricc ; the single series, which is pretty constant, corresponds in distance to the coarser ones in tlie other specimens. A careful examination of several specimens, however, has shown an occasional deviation from this rule, and smaller strife are sometimes present. In otbiM- characters, it is not essentially different from the last, and therefore can scarcely constitute a distinct species. Fig. 3 «. A fragment of this variety. Fig. 3 b. Transverse section, slightly compressed, showing the siphon, Fig. 3 c. An enlarged portion of the surface. Fig. 3 d. A fragment denuded of the shell, showing the lines of septa wiiich do not correspond to tlu' annulations. Position and locality. Same with the preceding. tKENTON LIMESTONE. 201 263. IG. ORTHOCERAS CLATHRATUM («. .s/j.). Pl. XMII. Figs. I a,b, c Compare Orthoceratiles nnihilahis, Hisinckr, Loth. Succica, 1837, pag 2.9, pl. 10, fig. 2. Cylindrical, gradually tapering', marked by moderately elevated subangular annulations, longitudinally marked by sluirp elevated lines distant j'j of an inch in the specimen figured; between and crossing these longitudinal lines are still finer transverse lines or striae, one third the distance of the longitudinal ones ; section circular ; siplumclel I have seen but the small fragment of the fossil here figured, l)Ut it is quite distinct from any other species in its surface markings. The transverse ridges are angular, and distant about one half tiie diameter ; the longitudinal lines are at equal distances, sharp and prominent ; the transverse striaj are stronger and more clearly marked than in the preceding species, and distinctly cross the longitudinal ones, producing finely crenulated edges. Fig. 4 a. The fragment, natural size. b. Magnified portion of the surface, c. Transverse section. Position and locality. In the lower shaly limestone at Middleville. . 264. 17. ORTHOCERAS VERTEBRALE ( n. sp.). ' '• Pl. XLIII. Figs. .5 a,b,c. Cylindrical, very gradually tapering, annulated with abruptly elevated angular ridges, which are distant from each other about one fourth the diameter of the tube, slightly arched upon the back, and direct on the ventral side ; surface marked by strong longitudinal stria? and finer transverse ones, giving it a cancellated appearance ; siphuncle apparently central or subcentral. The specimen figured is somewhat compressed, scarcely diminishing towards the apex. The septa are not visible, though there is some evidence of a siphuncle at one extremity. This species differs from any of the preceding ones, in the abruptly elevated and angular annulations, which are comparatively more distant from each other, and but slightly arched upon the back. The tube is more gradually contracted towards the apex, and the annulations less arched upon the back. In this respect it resembles a species in the higher strata, but is otherwise very distinct from it. Fig. 5 a. Ventral side of the fragment. Fig. 5 b. Portion of the dorsal side, showing the slightly arched annulations. Fig. 5 c. Transverse section of the specimen. Position and locality. In the compact limestone at Middleville. (From Mr. Wadleioh.) [ Pal-eontology.] 26 202 PALEONTOLOGY OF NEW-VORIi:. 265. 18. ORTHOCERAS ANELLUM. Pl. XLIII. Figs. 6 a, b, c, d, e,f. Orthoceras anellus. Conrad, Proc. Acad. Nat. Sciences, LS43, Vol. i, p. 334. Elongated, very gradually tapering, annnlated by prominent sharp sligliily sinuous ridges which are distant about one fourth the diameter of the shell, longitudinally marked by fine crowded wrinkled stria; ; septa moderately convex ; siphuncle excentric, but not marginal ; section circular. This species is readily distinguished from any of the preceding by the angular approxi- mate annulations, which are sharper and more elevated than those of any other species known in the rock. The length of the larger fragment figured is one inch and a half : the diameter at the larger extremity is half an inch ; at the smaller end, three eighths of an inch. The smaller specimen differs from the other in the strise being less crowded, though otherwise similar. Fig. 6 a. A fragment of the septate portion of the shell, b. Transverse section of the same. Fig. 6 c. Enlarged portion, showing the stria;, which, on a great part of the surface, are covered by a calcareous coating. Fig. 6 (/. A smaller fragment, e. Transverse section. / Portion of the surface enlarged. Position and locality. The larger specimen is from Mineral Point ( Wisconsin) , where it is associated with several other Trenton limestone species. The smaller specimen is from the lower part of the same rock at Middleville. (Caftmeio/ Mr. Conrad.) 266. 19. ORTHOCERAS UNDULOSTRIATUM (?!.j;).). Pl. XLIII. Figs. 1 a-k. Compare 0. trochlearis, Hisingee, Leth. Suecica, pag. 28, pl. y, fig. 7. Cylindrical, very gradually tapering, annulated by oblique undulating angular ridges, which are distant about one fourth the diameter ; annulations transverse on the ventral side, and abruptly arching towards the apex on the dorsal side ; surface marked by fine crowded transverse undulating stria; ; section circular ; siphuncle slightly excentric. This species is readily distinguished from the others, by the transverse undulating striae without longitudinal lines. The annulations are subangular, and abruptly arched on the dorsal side, in this respect resembling the longitudinally striated species. In its external characters, it corresponds with 0. trochlearis of Hisinger ut supra ; but the position of the siphuncle is more nearly central, and the annulations more angular. This species may be confounded with 0. hilincatum, and the variety of that species, where the shell is removed ; but it differs from those, in the more angular character of the TRENTON LIMESTONE. 203 annul.-itions, and thvit more extreme iindtilatioii upon the back, as well as the ilifferent direction of the striae and position of tlic siphuncle. Specimens of this species, as well as of the others, are often much flattened, presenting an elliptical section ; and the specimens which I have, show all grades in this respect, from circular to extremely elliptical, proving the latter forms to be due to compression ; which is probably true of all, or nearly all, the elliptical species of Ohthoceras. Fig. 7 a. Ventral side of a fragment, showing the nearly transverse direction of the annulations. The strias are scarcely preserved. Fig. 7 b. Dorsal side of the same; the specimen cylindrical. Fig. 7 c. Transverse section of the same. Fig. 7 d, e. Two smaller fragments of the species, compressed in diffLrcnt degrees. Fig. 7 /, g. Transverse sections of the two last. Fig. 7 h. An enlarged portion of the surface. Fig. 7 i, k. Another fragment and section, showi.ng the position of the siphuncle. The Orthoceratites trochlearis of Hisinger is from the more ancient calcareous strata of the palffiozoic period, in Dalecarlia (Sweden), corresponding- in position to our Trenton limestone ; which circumstance, together with the similarity in form and markings, induces me to make a comparison between (he two, believing at first that they were identical. Position and locality. In the lower shaly layers at Middleville. 267. 20. OB.i:\lOC¥.RA^ {Species undetermined). Pl. XLIII. Fig. S. Cylindrical, very gradually tapering ; annulations rounded, undulating, distant a little more than one third the diameter ; section circular ; septa moderately convex ; siphuncle central. This fragment possesses some peculiarities, which indicate a difference between it and those already described ; the annulations are more rounded than those of any other species, except the 0. textile and 0. bilineatum. Position and locality. At Middleville, in the lower shaly strata of the Trenton limestone. I have discovered several other imperfect specimens of annulated Orthocerat.\ in the shaly strata of the Trenton limestone ; but the surface markings are either obscure or obliterated, so that it is scarcely possible to point out specific distinctions. Nearly all these specimens are more or less compressed, so that the sections present variable elliptical forms, and this compression distorts the annulations in such a manner that these cannot be relied upon for specific distinction. In the absence of surface markings, therefore, it is impossible to characterize species with any degree of certainty. 26* 204 PALAEONTOLOGY OF NEW-YORK. 268. 21. ORTHOCERAS LATIANNULATUM (?i. *;).). Pl. LIV. Figs. 1 a, i. Elongated, cylindrical, anniilated by very strong rounded somewhat oblique ridges, which correspond to the distance between the septa ; septa distant from each other a little less than one third the diameter of the shell ; siphuncle small, excentric ; surface? Fig-. 1 a. A fragment, showing four chambers. 1 b. Section and siphuncle. We know nothing of the external characters of this shell, having seen only fragments of the casts, which are marked by strong and broad annulations. The siphuncle is com- paratively small, and could never have contained any embryo tube, like the somewhat similar species Endoceras annidatum. Position and locality. In the higher part of the Trenton limestone at Middleville. 269. 22. ORTHOCERAS JUNCEUM ( n. sp.). Pl. XLVII. Figs. 3 a, b, c, d, e,f. Slender, terete-cylindrical, tapering very gradually ; septa thin, distant from one fourth to one third the diameter ; outer chamber deep ; siphuncle small, central ; section circular; surface finely striated transversely, but without longitudinal striae. This species presents a surface marked precisely similar to Endoceras protciforme, var. lineolatum ; but the shell is mucli more slender and gradually tapering, the sipliuncle being always central. The septa, towards the outer chamber, are more closely arranged, sometimes two or three in the usual space of a single one. This is a constant species, presenting no important variation in its characters. All the specimens seen are imperfect, and the interior is often filled with crystalline matter, which obliterates the septa and siphuncle. The outer chamber, though incomplete, is proportion- ally very deep. Very little variation in size has been observed in all the specimens obtained. Fig. 3 a. A fragment denuded of the shell, showing a part of the outer chamber, and septate portion of the tube. Fig. 3 b. A smaller specimen, showing the marks of septa which appear to be slightly oblique. The shell covering the lower part of the specimen is crystalline, and preserves no markings upon the surface. Fig. 3 c. A small fragment, showing the convexity of a single septum. Fig. Z d. A. section of the last, showing the central position of the siphuncle. Fig. 3 c. A small fragment, showing the closer approximation of the septa near the outer chamber. Fig. 3/ A small fragment, preserving the shell and the striated surface. Position and locality. This species is known only in the lower concretionary beds of the Trenton limestone at Watertown, where it is abundant. (Stair Coiieriinn.) TKENTON LIMESTONE. 205 270. 23. ORTHOCERAS AMPLICAMERATUM (h. «jj.). Pl. LI. Figs. 1 a- g. Teretely cylindrical, extremely elongated, very gradually tapering; outer chamber profound ; septa distant about one third the diameter, very convex ; siphuncle excentric, small; surface 1 section circular. The peculiarities of this species arc its great length, and very gradual diminution from the larger extremity, and the distant and very convex septa, which seem sufficient to distinguish it from all other species known in this rock. In all the specimens examined, there is no enlargement of the siphuncle sufficient to admit the development of embryo tubes, unless they are mainly confined to the outer chamber, a longitudinal section of which does not reveal any thing of that kind. Fig. 1 a, b. Parts of the same individual, preserving a large portion of the outer chamber, with an equal length of the septate part of the tube. Fig. 1 c. A transverse section of the specimen, at the upper e.xtremity of 1 a, showing the excentric position of the siphuncle. Fig. y d, e. A fragment of another specimen, showing the same distance of the septa and excentric position of the siphuncle. - - Fig. 1 / A fragment of the septate portion of a much larger specimen. Fig. 1 g. Transverse section of the same, showing the position of the siphuncle. Position and locality. This species is found in the central and Iiigher part of the Trenton limestone at Middleville. (State Collection.) 271. 24. ORTHOCERAS STRIGATUM (». 5/;.). Pl. LVI. Figs. 1 a, b, c, d. Compare O. lineatum, Hisinger, pag. 29, pl. 9, fig. 6. Elongated, teretely cylindrical, gradually tapering ; outer chamber large ; septa distant about one fifth the diameter of the shell, very convex ; siphuncle small, central ; surface marked by flexuous elevated longitudinal lines, which are indistinctly visible on the cast. In the comparative distance of the septa, this species approaches some of the varieties of Endoceras proteiforme ; but the septa arc more convex, and the siphuncle always central. The longitudinal stria difTer essentially from the ridges in the next species, and are more distinct than in any of the species witliout annulations. The transverse stria;, if any exist, are mucji finer, and not preserved where the shell is exfoliated. This species approaches in character to the O. lineatum o[ Hisinger ; but the longitudinal stria; are stronger than in that species, judging from (he character of the smface, whicli is imperfectly preserved in our specimens. 206 PALAEONTOLOGY OF NEW-YORK. Fig. 1 a. A young specimen, with the shell partially exfoliated ; a few of the septa being indistinctly visible. Fig. \ b. A. fragment, showing the shell in a considerable degree of preservation. Fig. 1 c. A portion of the surface of the last enlarged, showing the flexuous character of the striae. Fig. \ d. A large specimen, preserving but indistinctly the strice. About twenty of the chambers are preserved, as well as a large part of the outer chamber. This specimen shows a small septate tube within the open extremity, but it is probably accidentally present. Position and locality. This species occurs in the higher part of the Trenton limestone at Middleville. 17. 2. ORTHOCERAS LAQUEATUM. Pl. LVI. Figs, 2 a, b, c. Reference Plate iii, fig. 12 of this Report. Small, teretely conical, somewhat gradually tapering ; surface marked by sharp elevated longitudinal ridges, alternating with finer intermediate ones ; no transverse striae ; septa? siphuncle? section circular. This is evidently identical with the species fig. 12 of Plate III. In that specimen, there are no indications of the intermediate finer lines, which are indistinctly visible in the larger specimen fig. 2 a, while they are very distinct in the smaller one. I have been unable to find a specimen showing either septa or siphuncle. Fig. 2 a. A fragment imbedded in compact limestone. Fig. 2 A. A small fragment, showing the intermediate finer strife. Fig. 2 c. A portion of the surface enlarged. Position and locality. This species is comparatively rare in New-York, but still has a wide geographical and somewhat extensive geological range ; the one figured on Plate III being found in the upper part of the Calciferous sandstone, while the specimen 2 a is found in the lower part of the Trenton limestone at Watertown. The smaller specimen is from the middle portion of the same rock at Middleville. 272. 25. ORTHOCERAS LAQUEATUM"? t;ar. a. Pl. LVI. Fig. 3. This specimen is marked by sharp longitudinal ridges, about equally distant with the stronger ones in the preceding figiues, but having no intermediate ones. The surface is well preserved, and presents an aspect somewhat different from the preceding, and may pcrliaps prove a distinct species. Position and locality. In the lower shaly strain of the Trenlon limestone at Middleville. TRKNTON LIMESTONE. 207 273. 5. ENDOCERAS* ANNULATUM ( n. sp.). Pl. XLIV. Figs. 1 a, b. Cylindrical, very gradually diminishing towards the apex, annulaled by broad rounded ridges, wliicii are equal to tlu; depressed spaces between, and distant from each other one fifth the diameter of the tube, slightly arched upon the back ; surface markings unknown ; septa deeply concave, and bending more abruptly backward just before reaching the • Since the name Endoceraa was proposed in the early pages of this report, I have learned from M. de Vekneuii. that the Genus Hyolithes had been previously proposed by M. Eichwald for the embryo tubes of the Orthoceras ; but it does not appear to have been adopted by subsequent writers. M. de Verneuil (Pal. Russia and the Ural Mountains, p. 33U) regards this tube as a mould of the interior of the siphon ; but since we find so many specimens having the embryo tube connected with the jiarent sliell, we can hesitate no longer in our decision regarding these bodies. I have felt some hesitation in pressing tlie adoption of the proposed name of Endoctras ; though I have no doubt that when we become better aciiuainted with these curious fossil bodies, such a separation will be admitted. There can be no longer any doubt of the development of the embryo sheatlis within the large siphuncle of many species of the Orthoceras ; while, in others, the siphuncle is evidently too small to admit of such development. That these embryo tubes do contain within them other tubes, which are septate, and which finally become developed into the form of the parent shell, 1 believe can be demonstrated, though we do not yet know all the steps of the process, or whether they are expelled from the siphon of the parent, or take the place of the enclosing body, which decays, and leaves the young and vigorous animal alone. The occurrence of several tubes, one within the other, would induce a belief that they were separable from the parent body without its destruction ; while, in other cases, the existence of a single tube enclosing anotlier difierently marked, suggests the idea that the former may not leave tlie siphuncle. From these facts, and from the evidence shown in the succeeding illustrations, it is desirable that any proposed name should include both the parent and embryo tube, as the latter has not an independent existence, but depends on the former, which differs from many of the Orthocerata in the enlarged siphon. There are, however, difficulties in the way of a clear separation of the species having this chai'acter, from the ordinary Orthoceras, which has a small siphuncle. In the young specimens which I have had an opportunity of examining, the siphuncle is always small, and it is not easy to conceive of its enlargement to such a degree as to admit of the development of the embryo tubes within it. Owing to these facts, and the possibility of confusion which will result in a multiplicity of species, it may be preferable for the present to indicate the Ktidoceras as a subordinate term under Orthoceras ; noting only such species as are proved to have tlie large siphuncle with enclosed embryo tubes. So far as my present knowledge of the Orthocer.\t.\ extends, those possessing the characters given above are confined to the Lower Silurian strata. All those of tlie higher strata, so far as examined, have simple small siphuncles, giving no evidence of enclosed tubes. Should this suggestion prove true in regard to this family of fossils, it may be of importance in its application to the identity of the older Silurian rocks in localities where other characteristics are not satisfactory. I am aware that a part of the description given as characteristic of Endoceras, is likewise applicable to the Actinoceras as defined by M. Bronn. But the tubes of Endoceras do not extend throughout the entire length of the sipluincle ; they are cylindrico-conical, filling the siphuncle at its outer extremity, and gradually tapering to a point. The space between this tube and the inner wall of the siphon is usually filled with crystalline carbonate of lime; but the tube is always smooth, and never in any manner presents radiating plates or verticillations. The character of ■. Actinoceras, as given by Bronn, is often seen in the Ormoceras, where a slender ill defined tube of crystalline matter extends through the centre of the siphuncle, with verticillating plates of the same material. These, however, never present, in American specimens, any evidence of organization, and are inconstant in their occurrence even in the same species. The Genus Endoceras, therefore, may be known from Actinoceras, by the internal tube being of a cylindrico-conical form, not continuous with the siphuncle, and having a smooth surface without radii or verticillations connecting it with the walls of the siphuncle. 208 PALjEONTOLOGY of NEW-YORK. siphuncle, more approximate than the annulations ; siphuncle large, subdorsal, containing a smooth emljryo tube ; section circular. A fragment of tliis species, two feet in length, is all that I have seen, thougli the original must have been at least three times this length. This is the largest of the annulated species, and is clearly different from all the others in the rock, which have small siphons, and are of far smaller size, with more abruptly elevated annulations. The annulations in this species are broadly arched on the dorsal side, which is at the left hand of fig. 1 a. The septa are direct and plainly arched, being distant about three fourths as far as the annulations. The internal tube, within the siphon, is not annulated. There is also, apparently, the apex of another tube within this one, which is not central ; but this appearance may be due to accidental displacement. Fig. 1 a. Lateral view of a fragment, showing- the arching of the annulations towards the left side. The fine dark transverse lines indicate the edges of the septa. Fig. 1 b. Longitudinal section of the last, showing the position of the siphuncle, convexity of the septa, and internal tubes. Position and locality. This species occurs in the compact lower strata of the Trenton limestone at Watertown. (Frvm Dr. Crawe.) ENDOCERAS PROTEIFORME {n. sp.) Plates XLV. to L., & LIII. General form cylindrico-conical, more or less elongated, often compressed, tapering somewhat unequally in different specimens ; young specimens terminating in an extremely acute point ; surface marked by distinct transverse stria, which usually appear like narrow subimbricating bands, with one edge well defined and more elevated than the other, more or less distinctly striated longitudinally ; stri^ varying from extreme tenuity to distinct elevated threadlike lines ; section circular ; septa distant from one fifth to one fourth the diameter ; siphuncle excentric or submarginal.* I ara able to characterize three distinct varieties of this species, which are the prevailing forms : these depend mainly on the surface markings of the young shell. The old shells are recognized by a large submarginal siphuncle, which usually contains a smooth cylindrico- conical embryo tube or sheath. This tube is sometimes irregularly tapering, and always free from visible ,'urface markings or sculpture. Within this embryo tube are the young shells, sometimes perfectly formed Orthocerata, and at other times destitute of septa or * This is a very variable species, wliich, in its extreme varieties, I have been disposed to regard as specifically distinct. TiiG engravings of the two first plates (xlv and xlvi) were made with this view; and the parent shell, with the smooth embryo tubes figured on the subsequent plates, was considered distinct, presenting no characters which could be identified as common with those figured on Plate xlv. It is only by some fortunate discoveries made since the engraving was comijleted, and while my descriptions are passing through the press, that I_am able to present the tnie characters of this protean species. The two plates xlv and xlvi were figured during the early part of the jireparation of this work in 1843, and my subse(]ucnt investigations have furnished the other specimens which appear on the following plates. This will account for the want of unity or completeness in the grouping of the different varieties. TKENTON LIMESTONE. 209 siphuiicle. Those young' shells are also frequently foiiiul separate from the parent shell or embryo tube, when we are compelled to rely ujjou the surface markings for their lie- terminalioii. 'I'lie position of the siphuncle, convexity of septa, and some other characters, are usually consiaul in all the varieties, wliich only exhibit a change in the character of the surface. In the aijseuce of septa and sijihuncle, which is of common occtnrence in the young shell, the character of the surface is reliabh; for determining the species. 274. 6. ENUOCERAS PROTEIFORME, var. TENUISTRTATTiM. I'l, XLV. Fics. 1 a,h; and Pi.. XLVII. Figs. 1 a, 4, and 2 a, b, c, iJ, e. This variety is known by the character of the surface, which is marked by regular transverse striae, sometimes appearing as if imbricated, or having one edge elevated. Tiie longitudinal stri;e are not more than one fourth as large as the transverse ones, and visible only under a magnifier ; they often become obsolete and scarcely jjerceplible, and the transverse strias assume a slightly imbricating and lainellose structure. The transverse striifi are often crowded together in bands or fasciae, as shown in the figures. In examining other specimens, we find the longitudinal striaj becoming more distinct, until finally they are equal to the transverse ones, and the entire aspect of the surface is changed. All the specimens examined of this variety are more or less imperfect, and, with a single exception, disconnected from the parent tube, and destitute of septa. In a specimen five inclics long, the diameter of the larger end is one inch and a quarter, while that of the smaller end is half an inch. In another specimen wilh a diameter of half an inch at the larger extremity, the smaller end is one eighth of an inch in diameter. Plate XLV. _ . Fig. 1 a. A fragment of the young shell, of the natural she. Fig. 1 b. An enlarged portion, showing the longitudinal stria3. Plate XLVII. ^ Fig. 1 ffi. A smaller and more slender specimen of the same species. Fig. \ b. A. portion of the surface enlarged, showing the cancellated lines. Fig. 2 a. This specimen presents very similar surface markings, and cannot be distinguished from the last, though the transverse strice are less prominent. The specimen consists of a double or triple tube ; the outer one 2 b showing externally marks of septa, which are distant about one fourth the diameter. The shell is exfoliated, and the surface markings are unknown. The inner tube, which is shown in the upper part of the figure, is likewise septate in its upper part, the septa being at about the same proportional distance as in the last. A portion of the shell still remains upon this one, which preserves the markings before described. Fig. 2 c. An enlarged portion of the surface; the longitudinal strio8 are too strong in the figure. Fig. 2 d. A. small portion still farther magnified, showing the proportionate size of the transverse and longitudinal stria. [PaLvEontologv.J 27 210 PALiEONTOLOGY OF NEW-YORK. Fig. 2 e. Transverse sertion of the specimen 2 a, showing the proportional diameters of the two, and the section of a still smaller tube within 2 a. In thi? instance, the specimen does not reveal enough to show whether the internal tubes are embraced within a siphuncle or not : the outer one is clearly marked with septa upon the outside, similar to the one within it ; but of the interior one we know nothing. The first internal tube is clearly not a cast within the outer tube; for it preserves a shell with surface markings, as well as septa externally. This figure is given to show the similarity, general form and surface markings, both in the septate and non-septate tubes, which belong ap- parently to the same species. 275. 7. ENDOCERAS PROTEIFORME, var. TENUITEXTUM. Pl. XLV. Figs. 2 ab, 3 a J, &, .5 a 6 c ; and Pl. XLVIII. Fig. 1 ab c. This variety does not differ in form from the preceding. The longitudinal and transverse striae are more distinctly elevated and threadlike, being of nearly equal size in both direc- tions, giving the surface a texturate or vveblike appearance. These stria3 are sometimes distinctly visible to the naked eye, while in other specimens they can only be distinguished by the magnifier. The septa are distant a little less than one fifth the diameter of the tube ; section circular ; siphuncle excentric. In some specimens of the last variety, the striee become more distinctly developed, and gradually assume the decided characters of such specimens as are described in the following figures. Plate XLV. Fig. 2 (I. A fragment of a tube destitute of septa, presenting strong transverse and longitudinal strite. Fig. 2 A. A portion of the surface enlarged. Fig. 3 a. A specimen with finer stricE, showing the marks of septa. Fig. 3 6. A portion of the surface enlarged. The specimen 3 a diminishes more rapidly towards the apex than the preceding one, and the cancellation of the surface is finer. Fig. 5 a. This specimen presents a double tube or sheath, the outer one (or embryo tube) being entirely smooth, while the inner one, which is but liule smaller, is marked by longitudinal and transverse strife as in the preceding figures. Fig. 5 i. A portion of the same enlarged to show the strite. Fig. 5 c. A section of the same, showing no septa or siphuncle. Plate XLVIII. Fig. 2. An embryo tube, containing a young specimen of this variety. It has been broken at a b c, and presents the sections a h c at the bottom of the plate, showing the septa and e.\centric si- phuncle. The surface marking of this young shell is precisely like fig. 3 « i, PI. xlv. TRENTON LIMESTONE. 211 276. 8. ENDOCERAS PROTEIFORME, var. LINEOLATUM. Pi.. XLV. rigs. 4 a, b, c, d, e; Pl. XLVI. Figs. 1 a A c, 2 a b, & .3; and Pl. XLVII. Figs. 1 a, A, e, d, e. Compare Orthoceratites centralis, Hisinger, Leth. Suecira, 1837, PI. 9, fig. 4. — bacillus, EicHWALD, 1S,30, Zool. specialis, Vol. ii, pag. 31, pl. 2, fig. 14. — — Id. 1S40, Sil. Syst. in Esthland, p. 94. — litiearis, Munster, 1S40, Beitr. zur Petrefacten, Heft iii, pag. 99, pl. 19, fig. 1 a, b. — — D'Archiac &.DE Verneuil, 1S42, Trans. Geol. See. London, New series, Vol. vi, part 2, p. 345. — bacillus, Verneuil, 1S4.j, Pal. Russia and Ural Mountains, pag. 353, pl. 24, fig. S a, b. This variety is usually more slender than the prevailing forms of the last, hut is not essentially different. The surface is marked by fine transverse striae, scarcely visible to the naked eye ; strias somewhat irregular, lamcUose, and crowded into bands or fascia. The siphuncle is equally excentric with the last, and the septa have a concavity of about one third their diameter ; section circular. The length of the fragment fig. 4, pl. 45, is 4 A inches ; the comparative diameters of the two extremities are as 4 to 1. In fig. 2, pl. 46, the length is 6^ inches, and the two diameters as 13 to 3, or about the same as in the other specimen. The surface of some specimens, when highly magnified, presents very minute or eva- nescent longitudinal stria-, approaching in this character to the var. E. tenuistriatum, into which it finally passes by a greater development of the longitudinal stria;. The transverse stria; are often imbricating, as if produced by the elevated edges of lamelhi; which are frequently broken or irregular. They also sometimes become vesicular, giving the surface a blotched appearance as in fig. 4 c, pl. 47. Towards the extremity they often become more distinct, and assume the character of sharp annulations. This variety differs from the 0. centralis of Hisinger, in the excentric position of the siphuncle, and in the finer striae, in which it approaches to O. bacillus, which has likewise a central siphuncle and more conical form. The finely striated surface of this species is very similar to one or two species in our higher strata ; but in those the striee are usually stronger, and they do not become, in any variety, cancellated in like manner with fine longiltidinal striae. It will be desirable, there- fore, to recollect these distinctions, in order to avoid confounding wliat are really distinct, and from different geological periods. Plate XLV. Fig. 4 ft. A young shell, with the outer chamber and apr.\ broken off. This specimen reprcsenis the prevailing Ibrm and dimensions of this variety. Fig. 4 b. Transverse section of the larger extremity of 4 a, showing the position of the siphuncle. Fig. 4 c. A fragment of the smaller extremity of the shell, which is annulated by fine sharp ridges. Fig. 4 d. The same enlarged. Fig. 4 c A fragment of another tube, marked as fig. 4 a, showing at the lower extremity a septum and siphuncle. 27* 212 PALEONTOLOGY OF NEW-YORK. Plate XLVI. Fig. 1 a. A fragment of the parent shell, enclosing an embryo tube within the siphuncle. The young shell within this tube is marked precisely as fig. 4 a, pi. 45. Fig. 1 b- Transverse section of the last, showing the large lateral or excentric siphuncle of the old shell. The shell is crushed, as shown in the upper figure, so tliat a perfect section cannot be given. Fig. 1 c. The surface marking of the young shell, enlarged. Fig. 2 a, b. The external shell, and a longitudinal section of a young shell, which is destitute of septa. Fig. 3. This is marked upon the surface as other specimens of the var. lineolatum. The septa in the figure are erroneously represented by the engraver much nearer than they are in the specimen. PX..4TE XLVII. Fig. 4 a. A fragment from the apex of one of these tubes, which is septate as in the larger specimens. Fig. 4 6. A transverse section. Fig. 4 c. A fragment which is annulated near the apex, and septate to the extreme point. Fig. 4 d. Section near the apex. Fig. 4 e. A fragment of a similar young shell, where the lamellose strite have become vesicular, giving a rough scaly appearance to the surface. I have given so great a number of figures of this variety, in order to show the various forms and aspects under wliich it appears. The separated and enclosed tubes, or young shells, are all identical ; some of them being septate, and others witJiout septa. It is im- possible to determine when these bodies assume the septate character, or whether they are always so except when the septa are removed by accident ; which may be the explanation of their absence in larger tubes, while they are present in smaller ones as I have shown in the preceding figures. 277. 9. ENDOCERAS PROTEIFORME, var. STRANGULATUM. Pl. XLVI. Figs. 4 a, b, c, tl e. It is not entirely certain that the character on whicli this variety is founded does not exist in the var. lineolatum ; since, in all the specimens of that one examined, the outer chandler is not preserved. The surface markings are ])recisely similar in the two ; some specimens being ({uite destitute of longitudinal stria;, while in others tiiey are faintly preserved, and the; surface resembles the var. tenuistriatum. The distance of the septa is from one fourth to one third the diameter of tiie tube, corresponding closely with those of the var. tenuitextum (PI. xlv, fig. 3 a). There is a slight difleicnce in this character in the two specimens figured, but tiie parent shells are also shown to be somewhat variable in the distance of the septa. The position of the siphuncle in the best preserved specimen is nearly central, while in another speciuKMi it is somewhat excentric. In this respect, the var. lineolatum, as well as other species of Okthoceras, is variable. In the small specimens with TKENTON LIMESTONE. 213 septa, figured on PI. XLVII, figs. 4 a, b, c, d, the sipliunclc is nearly central, and, in tiie smallest one, it scarcely deviates from that position. Tliis character, therefore, is not to be regarded as of primary importance. The dimension of the siphuncles in the two varieties is precisely similar in specimens of eciual size. Ill the figures given, one or two of tlie last septa are represented as more approximate than the other. This ciiaraclcr is likewise common to other species, and, I l)elieve, to nearly all tliosc wliere I have had an opportunity of examining this portion of the shell. In the variable character of the stria;, and the crowding together in bands, this one presents all the variations observed in the preceding variety. Fig. 4 ffl. A fragment, showing the contraction below tlic aperture. Fig. 4 h. Transverse section, sliowing the nearly central pobition of the siphunclc. Fig. 4 c. A portion of the surface of a specimen enlarged. Fig. 4 d. e. Two specimens denuded of the shell, showing a uniform character in the contraction of the tube, with a slight difference in the distance of the septa. ENDOCERAS PROTEIFORME. ILLUSTRATIONS OF THE OLD SHELLS, WITH THE EMBRYO SHEATHS OR TUBES SEPARATE Pl. XLVI. Figs. I a,b; Pl. XLVIII. Figs. 1, 2, 3, A ; Pl. XLIX. Figs. 1 a-e; Pi.. L. Figs. 1, 2, 3; and Pl. LIII. Fig. 2. These figures illustrate some of the many different forms in which this species occurs. They further show that the smooth embryo tube or sheath is almost constantly present within the siphuncle, as well as often separated from it. In all the specimens figured, it will be observed that the apex of this tube is directed towards the apex of the parent shell, thus precluding the idea of its accidental occurrence in this situation and position. The uniformly smooth surface of these tubes, which have never been found to contain septa or siphuncle, while on the other hand they contain sejjtate tubes with peculiar surface markings, indicates that they performed some other function, and proiial)ly only changed their position by accident, or the deatli of the enclosing animal, and consequent destruction of its habitation. Wo shall perceive, from the evidences to follow, that the young shell of this species, at least, was enclosed during its early stages, and probably always until fully developed, within a shelly tube. Plate XLVI. Fig. 1 a, b. This specimen has been noticed before, as containing a young shell of the var. tineolatum. The parent shell, or cast, has the septa distant about one fifth or one sixth the diameter of the shell. The embryo tube is smooth, slightly projcctine- at one extremity, and containing a smaller striated tube. The specimen is crushed, so that the section is imperfect. 214 PALEONTOLOGY OF NEW-YORK. Plate XLVIII. Fio-. 4. A fra"-mcnt of a larjre spncimen, composed of twenty or more chambers, one side of which is worn down, exposing the siphuncle, which contains the embryo tube, within which is a young shell a. Ficr. 4 i, h. The larger or embryo tube, which is broken at the lower extremity. FIt. 4 c. The siphuncle, the space surrounding the tube being filled with calcareous spar. This specimen shows, in a very satisfactory manner, the position of these tubes within the parent shell. Unfortunately we have not yet been able to obtain the apex of one of the larger shells, to determine whether the siphimcle continues of the same dimensions throughout. A small portion of the upper part only of the embryo tube is preserved in this specimen. Fig. 3. An embryo tube with a longitudinal section on one side, showing a slender septate tube within, which is nearly destroyed by weathering. Fig. 2. A similar tube, free from strice, and like the others. This tube has been broken at a, h, c ; and the transverse sections a, b, c, at the bottom of the plate, represent its appearance. The outer tube contains an inner one, which is septate throughout its entire length, and furnished with an excentric siphuncle, which is distinctly represented in the section a. An exposure of the surface of this septate tube shows precisely the same sculpture as that represented in the specimens 2 and 3 of plate 45, and also the small enclosed tube fig. 5 of the same plate. Fig. 1. A separate embryo tube, nearly perfect, and showing some inequalities near the base, apparently from contact with the inner side of the siphuncle. Plate XLIX. Fig. 1 a. Ventral side of a fragment, showing the siphuncle, which is worn through in the lower part, showing the smooth embr)'o tube. This specimen shows the more abrupt arching of the septa as they approach the siphuncle. Fig. 1 b. A fragment, preserving the embryo tube. Fig. 1 c. Transverse section of the last, which is slightly elliptical from compression. The embryo tube is pressed against the upper side of the siphuncle, the outline of which is only faintly re- presented. Fig. \ d. A. similar fragment, embracing a portion of the embryo tube. In this one the septa are a little more approximate than in the other specimens, but it docs not differ in other respects. Fig. 1 c. A nearly perfect embryo tube, with a few of the septa of the parent shell still attached. The tenacity with which tiiis tube retains its connexion with the parent shell, as shown in all these fragments, and particularly the last one where the outer shell is nearly destroyed, would indicate something more than accidental possession of the sipliuncle. In all these specimens, the septa are distant one fourth to one sixth the diameter of the outer shell. Plate L. Fig. 1 a. An embryo tube containing a yoimg shell. This specimen is more elongated, and less rapidly attenuating than the prevailing forms of the species. The outer tube is smooth, while the inner one is striated ; hut the crystalline condition of the rock renders it difficult to determine the character of the tulirs with accuracy. Fig. 1 b. This tube is more slender than the usual forms, but does not differ in other respects. Figs 2 a, b. Fragments of smooth embryo tubes, apparently of the same species, differing only in being TRENTON LIMESTONE. 215 more suddenly contracted and aculeate near the apex. This character docs not probably influence the young shells developed within them. Figs. 2 c, (1. Parts of the siphuncle separated from larger shells, still retaining the embryo tube within. Several such specimens have been found, though none in which the embryo tubes contain young shells. The similar character in these tubes, with the marks of septa upon the si- phuncle equally distant with the preceding figures, appears to be suflicicnt to warrant their reference to the same species. The siphuncle is marked by oblique or ascending annulations, indicating the junction of the septa. This ascending direction of the annulations is due to the lateral or cxcentric position of the siphuncle. The slight variation in the distance of the septa, < as marked on the siphuncle, is no more than is shown in difTcrent specimens in the preceding figures. Fig. 3. An embryo tube, more conical than any of the others. I have referred it, with some hesitation, lo the same species, until further discoveries shall prove it dislinct. Plate LIII. Fig. 2. A large fragment of this species, m which the embryo tube is preserved, while the surroundinof shell has been partially removed. All that part of the parent shell remaining is septate, the outer chamber having been broken off; which is likewise true of all other specimens of this species that have fallen under my notice. Position and locality. This species is found in the central and higher part of the Trenton limestone at Middleville and the valley of West-Canada creek, where it is far more abun- dant than any other species in the rock. It occurs less frequently at Turin, Lowville and Watertown, as well as in the same position in the Champlain valley. (State CuiUction.) I have been inclined to regard this species as very closely allied to, if not identical with, Orthoceratites duplex, as described by Wahlenberg and Hisinger (^id. Soc. Set. L'psal, Vol. viii, p. 88 ; Lcth. Sitecica, pag. 28, pi. 9, fig. 1); but the figures given by de Ver- NEUiL {Pal. Russia aiid the Ural Mountains) differ from tliat of Hisinger in the distance of the septa, and in having the sipliuncle quite marginal. This difi'ercnce will be seen by a comparison of the figures here given, with those of the author last cited ( pi. 24, fig. 7, and pi. 25, fig. 2 a, b) , where the distance of the septa is comparatively greater, and the siphuncle larger and ciuite marginal. The young shells of this species, however, arc re- presented as constricted near the aperture, as in the one under consideration. It is not improbable that more than a single species is knov/n in Europe under the name of 0. duplex, and the Endoceras proteiforme is represented in one of them. For synonyms and references of 0. duplex, see page 220, under Endoceras distans. 216 I'ALiEONTOLOGY OF NEW'YORK. 278, 10. ENDOCERAS PROTEIFORME? iw. ELONGATUM. Pl. LII. Fig. 1 a, b. Teietely cylindrical, very gradually tapering and extremely elongated ; septa distant about one sixth to one liftli the diameter of the shell ; siphuncle large, excentric. This species is closely allied to E. protciforme, in the character of septa and siphuncle. The external shell and embryo tubes have not been discovered, and it is from the great size of the siphuncle that I have referred the species to the Genus Endoceras. It is usually found in fragments, which are more or less compressed and distorted. The one figured is a small portion of a much larger specimen which was imbedded in a nearly perfect condition, but is broken from the weathering and decay of the rock. Fragments of this species are not unfrequent in the higher part of the Trenton limestone, but, like all the others attaining great size, it is nearly impossible to procure characteristic specimens. Fig. 1 a, b. Parts of the same individual, united as represented by the dotted line. Position and locality. In the higher shaly beds of the Trenton limestone at Middleville. ENDOCERAS PROTEIFORME. Pl. lviii. Fig. :. Reference page 20S of this Report. Since the preceding pages were in press, I have obtained from Dr. Emmons the specimen figured on Plate LVIII. It is apparently identical with the preceding, and very similar to the var. elongatiim, if this be a distinct variety of so variable a species. This one shows very conclusively that the young shell is developed within the siphuncle of the f»aront one, and furnishes more evidence than any other instance I have seen, that the old shell is succeeded by the young one, which assumes the place of the parent, which gradually decays. The specimen preserves twelve or more chambers of the parent shell, which are pierced by an extremely large submarginal siphuncle. This siphuncle embraces the young shell, which projects beyond the last septum of the old one preserved, nearly ten inches, and is imperfect at its extremity. The part of the young shell thus projecting, numbers between forty and fifty chambers, the lower or larger part of it L)eing partially enclosed by the embryo tube. Two specimens of this character have been found, and, when taken in connexion with the j)receding illustrations, leave little doubt as to the actual mode of development among the shells of this genus. It would appear from this one that the embryo tubes and young shells within keep pace in their growth with the parent, all the specimens of the young bearing a uniform proportion to the size of the enclosing or parent shell. Sullicienl, how- 4. ^1 tftENTON LIMESTONE. 217 ever, has already been said in reference to this part of ihe subject, and new facts are constantly presenting themselves in favor of the views here advanced, which, from their novelty, and the imperfection and ol)scinity of many of the specimens, have heretofore been regarded as untenable and unsatisfactory.* Position and locality. This specimen is from the valley of West-Canada creek, near Middlcville, and in the same position as those previously noticed. (Cabinet of Dx. Emmons.) Plate LIX. In the figures 1, 2, 3, I have attempted to give the precise markings presented on the surface of the varieties of E. proteiforme, which are somewhat more distinct than the litho- graphic impressions. Fig. 1 (7, b. var. tcnuilextum. The surface markings on two different specimens, somewhat enlarged beyond the natural size. Fig. 2 a, b. var. tenuistriatum. The surface markings on two different specimens, both slightly mag- nified. A careful examination shows a slight difference in the strength of the markings, which becomes more extreme in other specimens. Fig. 3 a. var. lineolatum. This one presents only transverse stria3 ; but some specimens show minute longitudinal ones, passing into the preceding variety. Fig 3. var. lineolatum. The surface is covered by fine spots or stigmata, as if some adhering softer substance had been separated from it. The same is observed in fig. 2 i, in a less degree. The markings are very similar to the bases of the cells of a Flustra. 279. 11. ENDOCERAS ARCTIVEKTRUM ( «. .s;).). Pl. LI. Figs. 2 a; b. Elongated, very gradually tapering ; septa distant about one third the diameter of the shell; siphuncle marginal (ventral), slightly contracted at the junction of the septa; section oval ( probably from compression ) ; embryo tube slender. The specimen is a fragment, preserving about eight or nine of the chambers ; but these, with the siphuncle, are different from any other species of this period. The siphuncle is remarkably narrow, somewhat longitudinally wrinkled, and slightly contracted at the junction of the septa. The small embryo tube contains a young shell, which has the appearance, in a small portion visible, of Orthoceras junceum ; but this cannot be demonstrated till we obtain other specimens. Position and locality. This species occurs, associated with the preceding, in the higher part of the Trenton limestone. * This view of the development of the Orthocer.'ITA was first imperfectly made known at the meeting of the American Association of Geologists and Naturalists, at Washington, in tSll, and subsequently more fully explained . at the Xew-York meeting in 1S16. [ Paleontology.] 28 SiilS PALJEONTOLOGY OF NEW-TOEK. 280. 12. ENDOCERAS ANGUSTICAMERATUxM (n. 5J5.). Pl. LI. Fig. 3. Teretely cylindrical, very gradually tapering ; septa distant about one sixth the diameter of the shell ; outer chamber deep ; siphuncle excentric? The specimen is a fragment somewhat compressed, giving a greater breadth in the figure than the actual diameter. The outer chamber contains a small tube, which is too obscure to determine satisfactorily its character, though indicating that the species belongs to the Genus Endoceras. The siphuncle of this specimen cannot be satisfactorily examined, and therefore I have some hesitation as to the true character of the fossil. The specimen is denuded of tiie shell, so that the surface markings are unknown. Position and locality. This species is found in the higher part of the Trenton limestone at Middleville. 281. 13. ENDOCERAS MAGNIVENTRUM («.:?;>.). Pl. LIII. Figs. 1 a, b, c, d, e. Elongated, very gradually tapering ; siphuncle very large, occupying about three fifths the diameter of the shell ; septa extremely convex, distant one eighth the diameter of the shell. The specimen figured is a fragment of an individual, which, when perfect, could not have been less than six feet in length. The septa are more convex than in any other species known to me, being in this respect slightly irregular as shown in the figure. The siphuncle is proportionally larger, and the septa more approximate than in any other species described. Fig. 1 a. A fran-ment, showing several of the chambers, with the large siphuncle projecting above. Fi"'. 1 b. An artificial longitudinal section, showing the proportional diameter of the siphuncle and shell, as well as the extreme convexity of the septa, which are correctly represented as soinewhat irregubr in this respect. FJ"'. 1 c. A transverse section of the larger e.xtremity, which is worn off obliquely. At d d the outer line indicates the edge of the siphuncle, the inner one being perhaps an exfoliation from the same, but too obscure to determine its character. At e, the embryo tube, with a young shell, is clearly distinguishable within the siphuncle. The position of the same is shown in the longitudinal section, which slightly cuts its outer edge. The small size of the embryo tube indicates that this section is distant from the outer chamber, at which point this tube usually fills the siphuncle. Position and locality. In the higher part of the Trenton limestone near Middleville. 282. 14. ENDOCERAS MAGNIVENTRUM ? var. Pl. LIV. Fig. 2 b. This specimen consists of a portion of an extremely large siphuncle, with a few septa attached. The septa are equally convex with those of the specimen figured on Plate LIII ; but their distance is equal or greater, though the diameter of the siphuncle is less. Position and locality. Same with the preceding. TRENTON LIMESTONE. 219 283. 15. ENDOCERAS APPROXIMATUM (n. ^;).). Pl. TJV. Fig. Q a. . Cylindrical, gradually tapering ; sopta with a convexity little more tlian one fourth their diameter, distant about one fifth the diameter of the shell ; siphuncle large, marginal, obliquely annulated l)y the thin edges of the septa. This specimen is a fragment, preserving about five or six chambers, with a portion of the siphuncle projecting above. . , >. . In many respects, this species resembles the E. proteiforme ; but the markings of the septa upon the siphuncle are more approximate in proportion to its diameter. In the one figured, they are distant about one third the diameter of the siph\mcle ; being actually nearer than those of smaller siphuncles of that species figured on Plate L, which are distant two fifths of the diameter of the tube. There is, however, still some obscurity in regard to these parts of the shell, and we are not able to decide whether their proportions are constant. Tliis can only be determined by a comparison of all the parts of a large number of specimens of authentic species. I have examined three specimens of what appear to be, very satisfactorily, the siphuncles of E. proteiforme, two of them containing a portion of the embryo tube. In all these the diameter is almost precisely the same, and the distance of the septa corresponds. On this account, I have thought it preferable to indicate this one as a distinct but approximating species. Position and locality. This species is found, associated with the preceding, in the higher part of the Trenton limestone near Middleville. 284. 16. ENDOCERAS DUPLICATUM (n. 5J3.). ^ ' Pl. LV. Fig. 1. r Cylindrical, gradually tapering ; septa distant about three eighths of an inch ; siphuncle extremely distended, and containing two embryo tubes, within each of which is a young shell. The only specimen seen is much compressed, and distorted so that its original form can not be made out. It evidently contains two embryo tubes, which apparently belong to the specimen. This is quite distinct from the Endoceras gemelliparum of the Black-river lime- stone, both in its general form, distance of septa and character of the tubes, showing a second species with double embryo sheaths. Position and locality. This species occurs in the upper shaly part of the Trenton limestone near Middleville. (Cabinet of iouy Gy.bhkkt), it.) 28' 220 PAL.EONTOLOGY OF NEW-YORK. 285. 17. ENDOCERAS DISTANS ( n. sp.). Pl. LVII. Figs. 1 a, b. Teietely cylindrical, very gradually tapering ; septa thick, distant one half the diameter of the shell, moderately convex ; siphuncle marginal, large ( more than two fifths the diameter of the shell ) ; external surface 1 section circular. The specimen figured is compressed towards the larger extremity, which gives it the appearance of enlarging more rapidly than it really does. The siphuncle is large, but is apparently of equal vi^idth throughout. The distance of the septa is much greater than in Orthoceras amplicameratum, and the siphuncle much larger and lateral. In these j)articulars it is clearly distinct from any described species. In the dimensions of the tube, position and size of the siphuncle, it corresponds precisely with a specimen of 0. duplex from Sweden ; but the septa are more distant than usually represented in that species. Our species will probably prove to be a true Endoceras, judging from the dimensions of the siphuncle, though the specimen under consideration apparently contains no embryo tube.* Fig-. 1 a.. A weathered cast of a fragment of this species. Fig. I b. Transverse section of the smaller extremity of the same, showing the large siphuncle. Position and locality. This species has been found only in the upper part of the Trenton limestone at Turin, Lewis county. * The following references and synonyms of the Orthoceratites duplex, are given from the work of Murchison and DE Verneuil on the Palaeontology of Russia and the Ural Mountains. Klein, 1731, Descr. tubulorum marinorum, PI. 2, fig. 1 a,b (e, d, exclusis). 7" espece d' Orthoceratites, Breyn, 1732, Dissert, de Polythalamiis, PI. 5, fig. 1-4. Orthoceratites duplex, Wahlenberg, Act. Soc. Sc. tJpsal, Vol. viii, p. 86. — spiralis, I''ischer, 1S29, Bull, de Moscow, p. 323. — — Pander, 1S30, Beitr. zur geogn. Russland, pag. 109, pl. 30, fig. 1. — — Fischer, 1S37, Oryct. de Gouv. de Moscow, pag. 125, pl. 10. — duplex, HisiNGER, 1S37, Leth. Suecica, pag. 2S, pl. 9, fig. 1. — — KUTORGA, 1S37, Beitr. zur geogn. Dorpat, pag. 32, pl, 5, fig. 9. — giganteus. Id. lb. pl. 6, fig. 6 (non id Sowerby). — spiralis, EicHWALD, 1840, Sil. Syst. in Esthland, p. 92. — duplex, QuENSTEDT, 18-10, Neues Jahrb. fur Mineralogie, p. 262. — — Troost, 1841, Si.xth Geol. Rep. Tennessee, p. 10. — — Verneuil, 1845, Pal. Russ. & Ur. Mountains, pag. 351 , pl. 24, f 7 ; & pl. 25, f 2 a 4. / TRENTON LIMESTONE. 221 Genus CAMEROCERAS (Conrad). Character. " Straight ; siphuncle marginal ; a longitudinal septum, forming a roll or involution with the margin of the siphuncle." The above description is quoted from Mr. Conrad {.Tour. ./lead. JVa/. Sci. Philadelphia, 1842, Vol. viii, p. 267); and although dissenting from his opinion of the characters in part, I have adopted it as a distinct genus, closely allied to Endoceras. There is no evidence of a longitudinal septum as described above, in the specimens I have examined ; nor is it probable that such a character exists. The character of the siphuncle, though resembling that of Endoceras, is different from any examined. 286. 1. CAMEROCERAS TRENTONENSE. Pl. LVI. Fisjs. 4 a, b, c. Cameroceras trentonensis. Conrad, Jour. Acad. Nat. Sci. Philadelphia, Vol. viii, pag. 2H7, pl. 10, fig. 3. Elongated, gradually tapering ; section elliptical, with diameters about as five to seven, slightly contracted at intervals ; septa distant about one third the longest diameter of (he tube ; siphuncle marginal, contracted between the septa, obliquely annulated at the junction of the septa. The single species differs from the Endoceras in its oval form, which is slightly con- tracted at intervals. The siphuncle is marginal, occupying one of the extremities of the ellipse, which is unequal at the two ends. The siphuncle is not only marked with the septa, but is contracted between them, in some slight degree, like Ormoceras. The oval form and contraction of the shell is constant and uniform in four specimens examined ; and the same is true of the one described by Mr. Conrad, on which account we may presume it to be the original form of the shell. This is a rare species, and the only one of the genus known. Fig. 4 a. A fragment of the shell, preserving about three of the chambers, beyond which the siphon is extended to an equal distance. Fig. 4 b. Another fragment, with the siphuncle still more extended. Fig. 4 c. Transverse section, showing the position of the siphuncle. Position and locality. This species occurs in the higher part of the Trenton limestone, associated with the other species of the same family, at Middlevillc. (State Collection.) 222 PALJEONTOLOGY OF NEW-YORK. 89. 1. ORMOCERAS TENUIFILUM? Pl. LVIII. Fig3. 2 a, b, c. Reference Ormoccras tenuifilum, Plates XV &. XVI of this volume. The specimen fig. 2 a is a part of a siphuncle, with a small portion of the shell adhering. The edges of the annulations are somewhat irregular and more sharply angular than is usual in this species, but otherwise it presents no important differences. Tlie specimen fig. 2 6, and section 2 c, is a fragment worn down on one side somewhat obliquely, showing the siphuncle in the lower part of the figure, which is precisely similar to those previously figured. These specimens have been given to me, the one by Gen. Spinner, of Mohawk, and the other by Dr. Budd, of Turin, Lewis county, as coming from the Trenton limestone. It is possible, that in the Mohawk valley, where the Orthoceratite limestone of the Black river is not clearly recognized, some of its fossils may be found in the base of the Trenton limestone. This is the only explanation I am able to offer at present, if the specimens are really from the localities given ; for among many hundreds examined from the central and higher part of the Trenton limestone, I have never observed a fragment of tlie Ormoceras. These specimens are figured in this place, though I do not regard them as characteristic of the Trenton limestone. 287. 1. CONULARIA TRENTONENSIS,* Pl. LVIII. Figs. 1 a, b, c, d, e,f. Compare Conularia quad/milcala, Miller. Sowerby, Min. Concliology, Vol. iii, pag. 107, tab. 250. — — D.iLMAN, Vet. Acad. Haiidlingar, 1824, tab. 4, fig. 3. — — HisiNGER, Leth. Suecica, 1837, pag. 30, tab. 10, fig. 5. — — Sowerby in Sil. Researches, pag. 626, pl. 12, fig. 22. — Suiverbii. Defrance, Diet, des Sci. naturelles. — — Bl.\inville, 182S, Malacologie, pag. 377, tab. 14, fig. 2 b, c, d, e. — — Troost, 1840, Fifth Geol. Rep. Tennessee. — — Verneuil, 1843, Pal. Russ. ar,d Ural Mountains, pag. 348, pl. 24, fig. 5 a, b. Pyramidal, obtusely quadrangular ; angles sulcate ; sides somewhat rounded ; a slightly impressed line along the centre of each side, from the apex to the base ; surface marked by sharp obliquely transverse ridges, which, extending from each angle of the shell towards (he mouth, meet those from the opposite angle in the centre of cacli side, producing a sligiiliy impressed line, along which the ridges arc less prominent; longitudinally marked by finer strise, which are slightly convergent towards the angles, and divergent from the centre of each side ( tliese strite are most prominent in the depressions between the trans- verse ridges ) ; septa transverse, very convex, smooth ; siphuncle excentric. • The Genus Conularia is usually placed under the Family Pteropoda. This species is provided with septa which are perforate as in Orthoceras, and, on this account, I have allowed those described to remain under Cephalopoda. TRENTON LIMESTONE. 223 Tlicrc is liulc difliciilty in identifying iliis curious and beautiful fossil, which is quite abundant in the Trenton limestone. The ohlicjuely transverse ridges and nearly vertical strife, which are always more promiiiont in the depressions tluui ui^on the ridges, are con- stant in a large number of specimens. The shell at the angles seems to be slighlly folded inward, jiroduciug a groove, wiiich interrupts tiie transverse ridges. It is but rarely that the septa and siphuncle can be seen ; the latter is usually excentric, but in one specimen there is an obscure appearance of a duplicate siphuncle. When the outer lamina of the shell only is removed, the cast preserves the sharp transverse ridges, the longitudinal stria; being obliterated. The entire cast is smooth, with a deep groove at the angles, and a shallow one on the centre of each face of tlie pyramid. . . ' . Fig. 1 a. A specimen (natural size), with the apex broken off. Fig. I b. Another specimen, more abruptly acute. Fig. 1 c. Transverse section of a, near the apex, showing the septum and siphuncle. Fig. 1 d, e. Lateral and transverse view of a fragment, showing the convex septum. Fig. 1 /. A portion of the surface enlarged. Position and locality. In the central and higher part of the Trenton limestone at Middle- ville, Jacksonburgh, Trenton Falls, and other places. 2SS. 2. CONULARIA GRANULATA (n. 5/;.). Pl. LIX. Fig. -2. Conical or pyramidal ; specimen compressed, tapering rapidly to an acute point ; angles marked by linear grooves or sulci ; surface marked by distinct transverse strife, which are crossed by finer longitudinal ones, giving, under a magnifier, a granulated or papillose appearance to the shell ; no septa or siphuncle visible. This species is quite distinctly marked ; and from the examination of several specimens, I have no doubt of the propriety of its reference to the Genus Conularia. The specimen figured is in soft shaly limestone, and presents no more than a thin laminar expansion. It differs essentially from the last in the character of its markings, which are also much finer, being scarcely visible to the naked eye. The surface is marked by longitudinal lines or folds, which are probably due to the folding of the shell from pressiue. Fig. 2 a. A specimen nearly entire, giving the general form of this species. Fig. 2 6. A portion of the surface enlarged. Position and locality. In the upper shaly portion of the Trenton limestone, associated with Lingula, Orbicula, ^"c. 289. 3. CONULARIA PAPILLATA (n.s/).). - " Pl. LIX. Figs. 3 a, ft. Compare Conularia quadrisuUata, Daxman, Vet. Acad. Handlingar, 1S24, pag. 374, pl. 4, fig. 3. Pyramidal, sulcated at the angles, gradually diminishing towards the apex ; surface 224 PALEONTOLOGY OF NEW-YORK. marked by regular lines of granulations or papillEe, which appear to be produced by regular transverse and longitudinal depressed striae, the spaces between which are elevated ; shell slightly folded inward at the angles, forming a shallow groove, which is partially marked by the granulations ; lines of granulations slightly curving upwards, or towards the apex, at the angles. This species is readily distinguished by the regularly arranged granulations, which are separated by equal transverse and longitudinal depressed lines. The surface is more coarsely marked than the last, and more distinctly granulated. These granules appear to be capable of separation from the shell, leaving small punctures ; or they are hollow pustules, which, when worn down, leave a small pit. Such a character is shown by D'Archiac and dk Verneuil in the structure of Conularia gervillei and C. gerohteinensis, from the older deposits of the Rhenish Provinces. The specimen figured is completely flattened ; and the longitudinal and transverse wrinkles, shown in the figure, are, in part, due to this pressure. The fragment here given diminishes towards the apex less rapidly than cither of the preceding. Fig. 3 a. An imperfect specimen, of the natural size. b. A portion magnified. Position and locality. This species occurs in the higher part of the Trenton limestone, near Middleville. 290. 4. CONULARIA GRACILE (n.5p.). Pl. LIX. Figg. 4 a, b. Slender, conical or pyramidal, slightly bent or arcuate ; angles sulcate, and a scarcely conspicuous depressed line along the centre of each side ; surface marked by sharp un- dulating transverse striae, and scarcely conspicuous longitudinal ones. This species is more narrow and elongated than either of the preceding ; the grooves on the angles are shallow, and the shell has less the appearance of being folded inwards along this line. The transverse striae are regularly arched downwards, or towards the mouth of the shell, between the straight longitudinal ones. The shell appears to be exceedingly thin and fragile. The three last species are comparatively rare, while the first is abimdant. They are apparently quite distinct in character, and, though much flattened, preserve the general aspect of other species of the genus. From the minute and indistinct markings, I had been inclined, on hasty examination, to refer them to the inner side of partially exfoliated shells of the C. trentonensis ; but that species never presents any similar markings, either as casts or partially exfoliated surfaces. We are able to add, therefore, to this genus, comparatively rare in species, four new forms from one of our older rocks, in a position lower than they have been before discovered. Fig. 4 a. A specimen, natural size; the apex broken off! Fig. 4 6. A portion of the surface enlarged. Position and locality. In the shaly upper part of the Trenton limestone near Middleville. Trenton limestone. 225 TRILOBITES OF TUE INFERIOR STRATA. It is ill tlic Trenton limestono tliat we are first made acquainted with this class of animals, in any considerable number. In the preceding- rocks, their remains are exceedingly rare and obscure. The few species known in the Ciiazy limestone are confined to a limited district, and lo a small iliickncss of sirata ; and their condition, also, is such as to render their characters indistinct and unsatisfactory. In the Birdsoye limestone, we are forced to depend on a few fragments for the determination of all we know in tliat rock. In the Trenton limestone, we have at least fifteen or sixteen well characterized species, and an immense number of individuals in a more or less perfect condition. They appear to have been as abundant, even, as the Orthocerata of this rock, or of tlie Black-river limestone. If we were to designate tiiis rock by its most striking, abundant, and peculiar fossils, it would very appropriately be teirncd the Older Trilobile limestone ; for nowhere in the series do we find, in a single rock or formation, so many species as in this. We may indeed confidently rely upon these fossils alone to ciiaracteri'/e the rock, at least throughout New- York, Canada, and some of the Western States. Those species in a iowtu' position can scarcely lead to any confusion, since they are few in number, and rare in all the localities examined. It is true that several species of this limestone reappear in the shales of the Hudson-river group ; Imt it lias already Ijeen sliown how iiUimatcly related are these two formations, constituting, in fact, liut a single natural group. This group, in its western extension, is characterized throughout by the presence of Triloijites, whicii, in New- York, are almost entirely restricted to the Trenton limestone. On this accoiuU, I have thought it lieiter to arrange the species of this rock in connection with those occurring in the succeeding shales. This arrangement seems the more necessary, since, in the western extension of this group, where the calcareous matter is augmented, many of the species continue throughout its entire thickness, terminating only with the deposit itself. The [jeriod of the existence of certain species in this position is limited in New-York solely by the cessation of calcareous deposits ; since it is clearly shown, that in other situations, where the formation continued to be calcareous, they existed for a longer time. I have already shown, in regard to the Brachiopoda and Monomyaria ( and the same is true of other fossils) , that the former are far more abundant in the Trenton limestone, in the calcareous part of the formation ; while the latter increase in the Hudson-river, or in the shaly portion of the group. That all these changes are dependent on the nature of the sediment, can be clearly sliown when we continue our observations to the western extension of the same formation. These facts should be lionie in mind by the geological student, in his investigations of the New- York strata, and the same succession of strata elsewhere. The general proposition regarding not only the Trilobites, but other fossils, may be [Palaeontology.] 29 226 paljEontology of new-yokk. staled ihus : 'J'linl all iliose loniis requiring ciilcareoiis sediment for their full development, will flourish during the deposition of such material, but become diminished or entirely exterminated when a change to argillaceous or arenaceous deposits takes place. On the other hand, those forms which require a very small proportion of calcareous matter, and flourish in the argillaceous mud, are diminished or cease altogether when a calcareous deposition supervenes. The forms which maintain a bare existence through a series of calcareous deposits, become extensively developed so soon as the nature of the sediment changes ; and tlie same may be said of those requiring calcareous sediment, during a period of argillaceous deposits. Those changes in the nature of the sediment, which may afTcct the majority of species in the way we have mentioned, will, in others, produce a total destruction or extermina- tion, because they are not adapted to encounter such extreme changes. This is, in a great degree, true of the Trilobites. Of the sjjecies known in the Trenton limestone of New- York, scarcely one fourth are found in the shaly strata which succeed ; and, with two exceptions (the Calymcne and Trinndeus) , those which are known are extremely rare. In a case like the present, where the higher shaly part of the formation much exceeds the lower calcareous part, reaching the thickness of nearly one thousand feet, we are very likely to lose sight of the characteristic fossils of the lower division of the group, and to regard them as of little or no importance in the identification of the higher strata. Neither are they, while the nature of the deposit continues uniformly argillaceous ; but so soon as the calcareous matter is increased, we find, spontaneously as it were, the appearance of forms vviiich we have l)efore known in the lower part of the formation. We may recollect, however, that not only are certain families affected by this change in the sediment, but different species of the same family are differently affected. In the present instance, the Triarthrus and Trinudeus become more abundant in the shaly portion of the strata, and we find two other forms which have not been seen in the calcareous part of the formation. Nearly all the characteristic genera of Trilobites appear at once during this period ; and all the subsequent forms in our strata are referable to these, or some modification of them. Some of them, as Phacops and Calymene, are continued throughout the Silurian and Devonian rocks, with scarcely any modification of form in some species, while others present a wide departure from the original type. The Platynoius, Illtcnus* and Jlcidaspis, reappear in the Upper Silurian strata; while Trinudeus, Ccraurus, Isotdus, Jlsaphus and Ogygia, arc unknown beyond ihe strata of (his period. * I rel'er here to Sumastis barriensis of the Niagara strata, vvliicli, tliougli it may conslitiitc a distinct genus, is nevertheless, constructed as the true Illanus in its important part-;. BIRDSEYE LIMESTONE. 227 TRILOBITES OF THE BIRDSEYE LIMESTONE. Plate LX. ( in part ). 291. 1. OGYGIA? VETUSTA. I'L. LX. Fig. 1. Compare Jlsaphus tyrannus, Murchison, Sil. System, pi. 21, and pi. 2.'), fig. 1 a, i. Caudal shield obtusely subtriangular ; middle lobe with 16 articulations, abruptly nar- rowing from above towards the middle, below which it is of nearly equal wichb ; lateral lobes with 15 distinct segments, the posterior ones meeting the middle lobe at a very acute angle, and terminating in a thickened or recurved border ; surface, near the margin, ■marked by imbricating lines or lamellose striee. The only specimen yet known is the caudal shield here figured ; it bears a very close resemblance to the A. tyrannus of Murchison, and, from its geological position, it is doubt- less a closely allied species. It will at once be recognized by the numerous segments of the caudal shield, the axis of which reaches only about ^ of the whole length. A few of the last articulations of the lateral lobes are nearly parallel to the central lobe, wiiile the first ones are nearly perpendicular to it. Each articulation of the lateral lobe is marked b}' a sudden and slight bending or contraction, about two thirds the distance from the axis to their outer extremity. The specimen is almost denuded of the crust, so that its original character cannot be entirely known. I have referred this species to the Genus Ogygia, on account of (he striated or lamellose surface, which does not belong to any of the species of Phacops witii wiiich I am ac- quainted. In the absence of other portions of the fossil, this reference must lie given with some hesitation. The surface markings of some species of Asapitus do not difler materially from this specimen, and' it may prove to belong to that genus. In the present state of our knowledge, we must regard the Asaphus and Ogygia as confined to the older silurian strata, appearing among the earlier forms of the Crustaceans, and limited to a single epoch of 2;eolo2:ical time. Position and locality. In the compact Birdseye limestone of the Mohawk valley. 29' 228 PAL7E0NTOL0GY OF NEW-YOKK. 292. 3. ASAPHUS1 EXTANS (n. ^p.)- Pi,. LX. Figs. 2, 2 a. Buckler unknown ; thorax with nine articulations visible, those of the lateral lobes bifurcate or grooved ; caudal shield very convex, with the middle lobe very prominent and terminating abruptly behind, the posterior extremity much elevated above the margin ; the three anterior segments of 1 lie middle lobe distinct, the posterior portion nearly smooth ; lateral lobes each with five segments, the two last ones terminating in a thickened marginal expansion, which extends beyond the middle lobe ; surface marked by fine imbricating lamellose strise. Two individuals only have been seen, and both these are from the Birdseye limestone. The fossil is remarkably distinct from the last, and is easily distinguished from any other in the lower strata, by the prominent projecting central lobe of the caudal shield, and the thickened margin. This species, having nine or more articulations of the thorax, varies from the true AsAPHus, and, in this and some other characters, approaches to Phacops. The caudal shield, however, showing but three distinct articulations in the axis, has more the character of AsAPHUs, to which genus I have provisionally referred the species. Fig. 2 a. A- caudal shield, b. Lnteral view of the same. Fig. 2 c. Another fragment, showing nine articulations of the thorax. Position and locality. In the Birdseye limestone of the Mohawk valley, and in the same position near WatertOWn. (Ca4inc< o/ John Gebhard, Jr., a?jrf o/ Dr. Emmons.) 293. 1. CALYMENE MULTICOSTA («. ^;j.). Pl. LX. Fig. 3. Thorax and caudal shield with at least 25 articulations. The specimen is from the Birdseye limestone of He la Motte, and, though very obscure, is evidently distinct from any thing we know in the older strata of New-York. The figure is presented in the hope of calling attention to the occurrence of such a species, and the explorations in Vermont will doubtless bring to light more specimens. Position and locality. Associated with Illcenns and Ortlioccras. He la Moltc, Lake Cham- plain. {Stale Collection.) TRENTON LIMESTONE. 229 TRILOBITES OF THE TRENTON LIMESTONE. Plates LX. (in part), LXI. - LXV., & LXVI. (in part). 40. 2. ILL.'ENUS CRASSICAUDA. Pl. LX. Figs. 1 a, b, c, d. Entomostracites crasstcauda. Wahleniierg, Nov. Act. R. Soc. Sc. Upsal, 1821, Vol. viii, pag. 27, no. 2, tab. 2, fig. 5 & 6; and pag. 294, no. I, tab. 8, fig. 0 & 0. niirnus crasskauda. Dalman, Vet. Acad. Handlingar, 1820, pag. 248, pi. 5, fig. 1 a, h, c. — — HisiNGER, Leth. Suecica, 18.37, pag. 10, tab. .3, fig. 4. — — PoRTLocK, Geol. Rep. Londonderry, IS43, pag. 3U0, pi. 10, figs. 3 a, 3 6, 4, 5. Illimns trcntonensii. Emmons, Geol. Report, 1S42, pag. 390, fig. 3. Compare I//irmis perova/is, Murchison, Sil. System, 1839, pag. 001, pi. 23, fig. 1 a, b. Oval with tlie longer axis more or less extended, convex ; buckler large, convex, rotund ; posterior extremities obscure ; eyes prominent, distant from the axis ; maxillary shield small ; thorax distinctly three-lobed, the divisions continuing a sliort distance into bolli the cephalic and caudal shields ; articulations ten, smooth, slender, those of tiie lateral lobes extended ; caudal shield large, semicircular, convex, having the rudiment of a central lobe ; entire surface smooth, or witii fine curving subiinbricating lamellose stria;. The general form of this species is variable from its contractility, none of the individuals yet seen being quite perfect. It is distinguished from Isotelus by the number of articula- tions, and by the more rotund and less equal extremities. In the rocks of New-York, the cephalic and caudal shields of tin's fossil are frequently found ; but from the delicacy of the articulations of the thorax, they are rarely preserved. Fig. 4 a. The caudal shield of a large individual. Fig. 4 b. Middle lobe of the cephalic shield, the lateral portions being separated at the sutures. Fig. 4 c. Lateral view of a small entire specimen. Fig. 4 d. Dorsal view of the specimen, showing the great width of the middle lobe, and abrupt incurving of the cephaUc shield. Position and locality. In the Trenton limestone at Middlcvillc, Watcrtown, Turin (New- York) , Carlisle (Pennsylvania), and in tlie upper pnrt of tiie Birdseye limestone on He la Motte (Vermont). 230 PAL.SONTOL0GY OF NEW-YORK. 294. 3. ILL^NUS TRENTONENSIS. Pl. LX. Fig. 5. Bumastis trentonensis. Emmons, Geol. Report, pag. 390, fig. 1. General form oval-ovate, very convex ; buckler semicirciilnr, rounded and ventricose in front, elevated behind ; glaliella scared}' distinct, narrow in the middle, but expanding before ; eyes approximate, large, form 1 facial suture making a deep and abrupt sinus at the eyes, from whence it turns outward and backward ; central lobe of the thorax broad ; segments plane, flat, continuing into the lateral lobes ; longitudinal furrows shallow, un- defined, slightly continuing into the buckler, and less distinctly into the caudal shield ; caudal shield sublriangular, very convex in the middle, and descending abruptly at the sides, the margin slightly expanded. Surface marked by fine converging imbricating striae, as in other specimens of the genus. This rare fossil was obtained by Dr. Emmons, from a boulder near Hogansburgh (N. Y.); but from other associated fossils, it clearly belongs to the Trenton limestone. The original of the perfect specimen has been lost, and our description is taken from a plaster cast. I have placed it under the Genus Illjenus, to which it properly belongs, the distinctions between this genus and the Bumastis being scarcely decisive. 295. 4. ILLiENUS LATIDORSATA (n. 5^.). Pl. LX. Figs. C a, b. General form broadly elliptical ; buckler convex, ventricose, thickened in front; thorax with ten narrow articulations ; middle lobe of the thorax very broad ; lateral lobes narrow ; surface marked by prominent imbricating lamellose striae. The specimen is a fragment, preserving five of the articulations very distinctly, and fragments of five others in the stone. The buckler is crushed and broken, so that it cannot be perfectly represented. The articulations arc very slender, those of the lateral lobes being suddenly bent forward just outside of the longitudinal depression. The great width of the central lobe (which is four times wider than the lateral lobe) , the well defined longitudinal groove, and sudden bending forward of the articulations of the lateral lobes, are distin- guishing features, and show it to be clearly distinct from the two preceding species. Fig. 6 a. The fragment, natural size. Fig. 6 b. Three of the articulations enlarged, showing the lamellose striae. Position find locality. In the Trenton limestone near Waterlown ( New- York ) . {Cnbinft nf Mr. .Alexandkr Fitch.) tKENTON LIMESTONE. 231 43. 1. ISOTELUS GIGAS.» Pl. LX. Figs. 1 a- i; Pi., I. XI, l'ip;s. ;! a - m, &, 4 a b c ; Pl. LXII. Kigs. 1 a i c, & 2 ; and Pl. LXIII. Jlsaphtts platycepha/us. Stokes, 'I'rans. Geol. Soc. London, New series, 1822, Vol. i, p. 208, pi. 27. Jsoteltis gigns, and I. planus. Dk Kay, 1824, Ann. Lye. Nat. Hist. New-YorU, Vol. i, pag. 170, pi. 13, fii;. 1,2; and pi. 13, fig. 1, 2. Isoteliis gigas. Green, Monograpli, 1S32, p. 07 & 03. Isotelus Cyclops, I. megalops, and /. stegojis. Id. lb. p. 09, 70 & 71. Asaphns platycephahts. Bucki.axd, liridgw. Treatise, Vol. ii, pag. 7(i, pi. 45, fig. 12. Isotelus gigus. Vanuxem, Geol. Rep. New-York, 1S42, pag. 40, fig. 1. — — Kmjions, Geol. Rep. New-York, 1842, pag. 389, fig. 1. Isotelus gigas, and /. planus. Poktlock, Geol. Rep. Londonderry, 1S43, pag. 296, pi. 7, figs. 1, 2 & 3. Compare .isaphus cornigerus, Hrongxiart, Crust, fossiles, 1S22, pag. IS, pi. 4, fig. 10 (not pi. 2, fig. 1 A, b). Brougniartia isotela, Eaton, Geol. Text-Book, 1S32, pi. 2, fig. 19. ,1saplius potriiii, Murchison, Sil. System, 1S30, pag. Gdl, pi. 23, fig. 9. Isotelus powisii, Portlock, Op. cit. pag. 297, pi. 0, fig. 1. - ' Isvleltis ovaius, I intennedius, I. schrops, and other figures. Portlock, Op. cit. pag. 297 - 299, plates 0, S, 9 & 10. Isotelus megistos, Locke, .Am. Jour. Science, 1S42, Vol. xlii, p. 300. — — TraiLS. Assoc. Am. Geologists and Naturalists, 1^43, Vol. i, pag. 221, pi. 6. General figure oval-oblong, with the sides rather straight ; buckler in the form of " a spherical triangle," obtuse or more or less rounded at the posterior extremities ; cephalic shield convex in the middle, rapidly descending in front and at the sides, margined by a narrow elevated rim or border ; eyes sublunate, prominent, " subpedunculatcd," strongly supported on the inner and concave side by a projection of the glabella; facial suture continuing from the centre of the front, nearly parallel to the margin, until in a line with the eye, when it turns backward, and leaving the eye upon the maxillary portion, turns outwards and backwards, coming out at the base of the shield distant from the angle ; thorax with eight articulations, the middle lobe about once and a half the breadth of the lateral lobes, the longitudinal grooves continued slightly into the Imcklcr, and more dis- tinctly into the caudal shield ; segments of the middle lobe Hat above, those of the lateral lobes with a groove on ibeir upper surface, extending nearly half way to their extremities ; caudal shield of nearly the same form as the buckler, presenting e.xtcrnally some evidence of a trilobate character, sharpened at its upper lateral angles, and having a single trans- verse groove on each of the lateral lobes extending from the axis more than half way to the margin ; entire surface finely punctulated. When the crust of the buckler is removed, a narrow shallow groove is visible at the base. In young specimens the caudal extremity is more pointed, and ])resents the marks of eight anchylosed articulations ; in older specimens, these increase in ntimlier, but the external * I have adopted the name of De Kay, though aware that the name of Stokes has precedence in point of time. If it be proved that Isotelus cannot be separated from Asaphus by any important characters, we must abandon the genus ; but at present it is well known to all .American naturalists, and a change of name would not bo attended with any beneficial results. 232 PALiEONTOLOGY Ot" NliW-YORK. crust presents scarcely any traces of them. When the crust is removed, liowever, they are often very distinct (as in PI. 61, fig. 3 ^). When the thick crust of the inargin of the caudal shield is separated, the lower part presents a striated surface, which is also common to corresponding parts in the buckler, and apparently to the entire under surface of the animal, as well as to those portions of the articulations which come in contact with each other. After examining several hundred specimens of all sizes, and in every possible degree of perfection, I am satisfied to refer all those of New-York to a single species. The models of Green present no greater differences in form than may be witnessed in specimens ordinarily found, and which, if regarded as specific, would give us a different species for nearly every individual ; depending on difference of size, in the manner of being imbedded, the nature of the mass in which it is found, etc. The same remark will apply to several of the species given by Capt. Portlock. I have therefore thought it better to bring back the whole to llie original species ; believing that sucli a course will cause far less difficulty and confusion, than an attempt to identify and establisli distinct species upon characters which are in- sufficient, or so variable as not to l>e relied upon. Notwithstanding the great number of individuals which existed at the period of the Trenton limestone, it is extremely rare to meet with perfect specimens. This is, doubtless, in part owing to their great size, which exposed them to be more frequently broken, than the smaller species ; but it would appear, also, that they were more easily separated at their joints and sutures, than some other species, as shown from the condition of the parts which we find. Owing to this circumstance, we are able to illustrate its structure more perfectly than in most other species; and I am induced to present many of tlicse figures, not only Avith this view, but also to aid students in difficulties which I find are not uncommon in identifying isolated portions of the fossil. Plate LX. Fig. 7 a. A specimen preserving the thorax, caudal extremity, and central lobe of the buckler. (The base of the latter is too far extended in the engraving.) The caudal shield is denuded of the shell. Fig. 7 b, c. The maxillary portions or cheeks of the buckler. These have been supplied from specimens which are frequently found separated from the other parts, e e. The eyes, which arc always separated with the maxilla;. Fig. 7 d. The inside of the lower crust of the cephalic shield, the upper part having been separated at the lateral suture. Fig. 7 c,/ The lower side of the cephalic shield, towards the extremities of which the upper and lower crusts are folded together, so as to present the appearance of projecting spines. Fig. 7 g. The epistoma or labrum, the place of which is indicated in the centre of the lower side of the previous figure. The epistoma is rarely found connected with the head of the fossil. It was attached by a suture, and probably easily separated. Two circular depressed spots are re- presented in the figure, which are always observed in well preserved specimens : these probably indicate the points for tlic attachment of muscles or tendons upon the inside. The TKENTON LIMESTONE. 233 horns or processes of this organ are flat on the outside, and angular on the inner side. The crust of the lower side of the head, as above, shows a longitudinal suture extending- down the middle to the point of junction at the epistoma, but it docs not continue into this organ. Fig. 7 h. The central lobe of the cephalic shield. Fig. 7 i. The same part of a larger individual. Specimens of this kind are very frequently found, and are sometimes mistaken for parts of other trilobites. The lateral or maxillary lobes of the buckler often remain connected, while the central portion is separated at the suture. Plate LXl. Fig. 3 a. The buckler of an individual of medium size. This is more extended in front, and the eyes are more prominent than usual. Fig. 3 b. The caudal shield, corresponding in size to the buckler. The crust is removed, showing the lines of the articulations. Fig. 3 c. A portion of the surface of the buckler enlarged, showing a peculiar punctate structure which is scarcely visible to the naked eye. Fig. 3 d, e. Lateral and dorsal view of a small perfect specimen. The figure preserves all the important marks of the species. The buckler is somewhat compressed or bent in front, so that the facial suture is not shown to its full extent. This specimen is from Kentucky. {Cabinet of W. II. Peask.) Fig. 3 / Buckler of an individual of ordinary size. The eyes are prominent, but less proportionally elevated, and the whole less convex than the specimen 3 a. The course of the facial suture is distinctly vi.'-ible. Fig. 3 g. Caudal shield corresponding in size to the buckler 3 f. The marks of the transverse segments scarcely visible. Fig. 3 A. View of the eye of 3/, natural size, as seen looking forwards and outwards. Fig. 3 i. Oblique front view of the eye, which, under ordinary magnifying glasses, presents no granula- tions. Fig. 3 k. The labrum or epistoma, showing the inner or upper side. Fig. 3 m. A portion of the same enlarged, showing the striae upon the surface^ Fig. 4 a, b, c. Front, lateral, and dorsal views of the original specimen, to which Green applies the name of /. cijdops. Its proportions vary in no essential manner from other individuals of /. gigas. It is abruptly bent downward before, and the sides of the buckler are worn off", giving it the appearance of being narrower than usual. The whole specimen is much worn, and the crust almost entirely removed. The bases, only, of the eyes remain, which are round ; but this is true of all the others, when worn off in the same manner. Plate LXII. Fig. 1 ffl. A specimen folded so that the two e.xtremilies meet. The fossil is rarely found in this condition ; and in many instances where it has originally assumed this form, it has been subsequently crushed. Fig. 1 b. The caudal shield of a young individual, showing the marks of the articulations, and pre- serving the trilobate form more perfectly than older specimens. Fig. 1 c. A magnified portion of the surface of one of the articulations of a large individual, showing, in addition to the punctures upon the surface, a series of curving impressed lines. The latter [ Palaeontology, j 30 234 PALEONTOLOGY OF NEW-YORK. are not observed upon the buckler or caudal shield, which preserves a double series of punctures as shown in PI. 61, fig. 3 c. Fio-. 2. This specimen has the crust almost entirely removed. The upper part of the cephalic shield has been separated at the marginal suture, leaving the lower portion with the epistoma attached, as represented m the figure. The position of the eyes is represented by the letters e e. This interesting specimen was obtained by Mr. Bullions, Civil Engineer, from the Utica slate on the Mohawk valley, and by him presented to the Cabinet of the Albany Institute. Plate LXIII. The lower figure represents the caudal shield, and five of the articulations of a very large specimen, from the Collection of Mr. Moore, of Trenton Falls. The superior covering is removed, showing the converging strife in the deep groove along the margin. This individual, when perfect, could not have been less than nine or ten inches in length. The buckler is of nearly cor- responding size. The narrow thickened border, and course of the facial suture, are well shown in this specimen. The posterior angles are represented in the figure too much rounded, the one from being broken, and the other from being covered by the stone. The eyes are nearly perfect and remarkably prominent. Position and locality. In certain portions, particularly the bhick fine-grained layers, of the Trenton limestone, this species is often abundant, though perfect specimens are exceedingly rare. The bucklers, caudal shields, and fragments of the thoracic segments, are met with in nearly every locality of this rock in the State of New-York. Beyond the limits of New-York, we know of its existence in Canada, Ohio, Indiana, Kentucky and Tennessee, being equally characteristic of the Lower Silurian rocks in all these places. In our own State, it is occasionally found in the Utica slate and Hudson-river group, though it does not appear to have flourished in these situations. In Ohio, one or two other species have been described as occurring in the lower strata ; hut in no instance, within my knowledge, has it been found in any rocks above the Hudson- river group. The species, therefore, and even the genus, may be regarded as eminently characteristic of the inferior rocks ; and a single fragment, so far as our present knowledge extends, is sufficient to decide the age of the rock in which it occurs. The more calcareous nature of the older strata in their western extension, and perhaps other cavises combined, have continued the existence of this species, in great numbers, long after it had nearly or quite ceased in New- York ; and its remains characterize the higher portions of the Blue limestone of Ohio, Indiana and Kentucky. TKENTON LIMESTONE. 2.35 Genus P L A T Y N OT U S (Conrad).* "Depressed, apparently not contractile ; buckler witli oculiferous Uibercles sitnaled on the front or middle lobe ; abdomen with about 12 articulations ; mesial and lateral loijcs depressed ; ribs with oblique grooves." This description may be amended, so as to read : Buckler five-lolied, or witii the central lobe trilobate ; oculiform tubercles situated on the outside of the lateral divisions of the middle lobe (or of the inner lateral lolies) ; thorax with 11 articulations. (These characters will be more fully illustrated under the descriptions of the genera of Trilobites.) This genus was foimded by Mr. Conrad, for tin- reception of the Paradoxides boltoni of the Niagara group. It is clearly distinct from any other established genus, unless it may be the Lichas of Dalman. The following species is clearly referable to this genus, possessing a very similar character to the P. boltoni. It is also probal)ly identical with JYultainia hibernica of Capt. Portlock, cited Ijelow, being a species of the same genus. f 296. 1. PLATYNOTUS TRENTONENSIS. Pl. LXIV. Figs. 1 a, b, c, ella separated from the cheeks by a deep broad groove, wider behind or often of nearly equal width throughout, with three tubercles or lobes on each side, the anterior one often obscure ; cheeks triangular ; eyes truncato-conical, situated a little out- ward from the inner edge of the cheek ; facial suture terminating nearly in front of the eye ; thorax with thirteen segments, those of the lateral lobes with a deep groove extending from the base more than half way to the extremities ; caudal shield small, with seven segments in the middle lobe and five in each lateral one, the latter with an impressed line or shallow groove the whole length. This species is very abundant in the dark compact portions of the Trenton limestone, though perfect individuals are comparatively rare. A comparison of specimens from this rock in New- York and Ohio, with those from Gothland in Sweden, shows no essential difference. Tlie only difference in the Niagara specimens is a rougher granulation of the surface, and a slightly greater width of the front of the glabella, which latter character is variable from different causes. The large specimens fronj the Schoharie grit present a slight difference in ihe direction of the facial suture, as well as some other characters which may prove essential in the designation of the species. On comparison with a well preserved specimen of the Calymene blumenbachii from Dudley in England, the most obvious difference consists in the slight but conspicuous tuberculation of the segments of the middle lobe of the thorax, at their extremities. The articulations of the lateral lobes of the caudal shield show a strong impressed line towards their extremities, but not towards the base, as in well preserved Trenton specimens. The glabella of the Dudley specimen is broader in front than tliat of the Trenton species, and its surface is more coarsely granulated. In other respects, the two resemble each other. Fig. 3 a. A large specimen from the Trenton limestone, with the buckler abruptly curved downward in front. This specimen is of unusually largo size. Fig. 3 i. A small specimen from the same rock. 3 c. Lateral view of the same. Fig. Z d. A. small specimen from the Hudson-river group, showing no essential difference of cliaracter. Fig. 3 e,f, g. Three views of a contracted specimen from the Bhie limestone of Ohio. This is the C. callicepkala of Green ; but I am unable to perceive any essential dif- TIIENTON LIMESTONE. 239 ferencc between it and specimens of the same size from Trenton falls. The buckler is some- what flattened on ihe top, and the lobes of the glabella arc more distinct than is usual in this species. I have examined the original specimen described by Green, which presents scarcely so great a deviation from the prevailing forms as does this one. The figure of BuRMEisTER, who adopts this species, is widely diffcrrnt from the original, in the cabinet of J. P. Wetherell, Esq., which is now in the Academy of Natural Sciences of Phila- delphia. Fig. 3 h. Lateral view of the eye of this species, enlarged. The eye is obtusely conical, with a de- pression or cavity at the ape.x, which is granulated as shown in fig. 3 i. From the oblique conical form, this depression opens outwards and upwards, being protected on all sides by a thick crust. This portion may have been originally of softer material, which contracted on the death of the animal. Fig. 3 Ic. The buckler of this species separated at the facial sutures, showing the form of the maxillary portions y y, which embrace more than half the oculifonn tubercle. Fig. 3 I. Front view of the buckler, showing the termination of the facial sutures. X is the labrum, which occupies this position beneath the buckler ; but I have not been able to determine the exact form and proportion of the part intervening between this and the front of the glabella, to which it is attached by a suture. Fig. 3 m. The same enlarged, showing the lines of the frontal suture, and the termination of the facial sutures. Fig. 3 n. The inside of the glabella, having the maxillary and basal portions separated. It is evident that the characters of the eyes, or oculiform tuljercles, in Calymene, have not been well understood, from the usually ill preserved condition of this part of the fossil. The granulations mentioned, though not as regular or strongly marked as in Phacops, are nevertheless interesting and important, since this small oval part of the tubercle must have been alone the seat of vision. The labrum figured was discovered beneath the glabella of a specimen, its posterior extremity extending back as far as the first segment of the thorax. See also the same organ in C. beckii, PI. 66. Position and locality. This species is abundant in the Trenton limestone, at many locali- ties. The vicinity of Middleville and Trenton falls has furnished many thousands of specimens in a more or less perfect condition. It occurs also at Herkimer, Jacksonburgh, Turin, Lowville and Watertown ; and at Plattsburgh, Glen's falls, and other places in the Hudson and Champlain valley. It is likewise common in the same rock at Bay Quinta and other places in Canada. It is found in the Hudson-river group at Turin, Lowville and elsewhere, and it appears to be almost equally abundant in the western extension of this group ; occurring at Cin- cinnati, Lebanon, Oxford and other places in Ohio ; at Maysville and Frankfort, Kentucky; at Madison, Indiana ; and at Mineral Point, Wisconsin. This is one of the most abundant and widely distributed fossils of any in our palaeozoic strata ; and the only detraction from its value in the identification of strata, is the great similarity di absolute identity of the species in the shale of the Niagara group. (Slate CulUction.) 240 PAL-ffiONTOLOGV OF NEW-YORK. Genus ACIDASPIS ( Murchison ). ODONTOPLEURA ( Emmrich). I prefer to adopt the name of Murchison, which is well understood in its application to a species in the central or higher Silurian strata of New-York. It is not easy to determine whether the name of Murchison or Emmrich has priority in regard to time ; the works of the former, and the dissertation of the latter, bearing the same date. Dr. LovEN {Ofv. Vet. Acad. Sci. Stockholm, 1845) has attempted to show the identity of AciDASPis, Odontopleura and Ceraurus ; but the latter genus is quite distinct, as I shall show in the succeeding pages. 299. 1. ACIDASPIS TRENTONENSIS. Pl. LXIV. Figs. 4 a, b, c, d, e,f. Compare Ceraurus crosotus, Locke in Am. Jour. Science, 1843, Vol. xliv, no. 2, p. 346. Odontopleura ovata, Emmrich, Dissertation, 1S39. — bispinosa, Id. Scient. Memoirs, 1845, Vol. iv, part 14, pag. 275, pi. 4, fig. 12. Cephalic shield subcrescent-form, broadly rounded and dentated in front, produced into elongated spines at the posterior angle, the connate segment at the base distinct ; glabella of nearly equal width, somewhat straight, and having a projecting spine at the posterior margin, and two distinct rounded lobes or tubercles on each side, or in the furrow between the glabella and cheeks, being nearly disconnected with the former ; cheeks with a lon- gitudinal or slightly oblique groove from the inner posterior base of the eye, extending forward, and a ridge from the front of the eye, extending forward and inward along the facial suture ; outer margin of the maxillae fimbriated ; eyes round smooth tubercles ; body ten-jointed ; lateral lobes with a row of small tubercles on the anterior edge of each articulation ; caudal shield two-jointed, with a spinous margin. In our specimen, both the spines from tlie angles of the buckler, and the one from the posterior part of the glabella, are broken oft". That they existed in accordance with other species of the genus, is clear from the appearance of the remaining portion. The extremities of the pleura, or lateral articulations, are prolonged into short spines as in the Odontopleura bispinosa of Emmrich cited above, and in the figure of the same species given by Bur- MEisTER ; but the character of the caudal extremity, and the serratures on the margin of the buckler, as well as the tubercles of the middle lobe of the thorax, as represented by these authors, are different from our specimen. The form of the buckler, the tubercles of the glabella, eyes, etc., clearly point to Acidaspis of Murchison. We have another ana- logous species in the Delthyris shaly limestone, which resembles the Acidaspis brightii of England. tRENTON LIMESTONE. 241 I have examined fragments of a similar species in the collection of Mr. Carly of Cin- cinnati ; but tlie finil)riae beneath the maxilla; in tiiat one are longer and fewer in number, which I conceive to be a specific distinclion. In that species, the central posterior spine of the buckler is very long, extending half the length of the thorax. A comparison of our species with the one figured and described by Dr. Locke ( cited above ) , shows several points of resemblance. The fanbritc beneath the maxilla; are the same in number; but the rc])resentalion of the C(;phalic shield, particularly the glabella, is (|uite different, as also the nodes or tuljercles upon the segments of the thorax. These differences are clearly distinguishable on a comparison of the figures. The species of Locke is undoubtedly an Acidaspis, and not a Ceraurus, which differs in many essential characters. Fig. 4 a. Front view of the specimen, which is folded (natural size). Fig. 4 b. The same enlarged, to show more distinctly this part of the fossil. Fig. 4 c. Dorsal view (natural size), d. The same enlarged. Fig. 4 e. The caudal extremity and part of the thorax enlarged. Fig. 4/ Margin of the maxilloe enlarged, showing the fimbrise. Position and locality. I have received this specimen from Mr. Logan, the Geologist of Canada, who obtained it, with the Calymene senaria and other Trenton limestone fossils, at the Bay of Quinta on Lake Ontario. 300. 2. ACIDASPIS SPINIGER (n. s/).). Pl. LXIV. Fig. 5. Glabella oval, margined laterally by a deep broad groove, front nearly straight, pos- teriorly extended into a strong spine ; surface tuberculated. This fragment is all that I have seen of this species within the State of New- York : another similar one, with a spine an inch in length, has been obtained by Mr. Logan near Montreal. The western species alluded to, bears some analogy to this one. I have referred this fragment to the Genus Acidaspis, from the long posterior spine of the glabella, which is known to me as occurring only in this genus and Trinucleus. The tuberculated surface is likewise peculiar, and different from that of other genera in the lower strata. Position and locality. In the central part of the Trenton limestone in the Mohawk valley, and in a similar position near Montreal. [Paleontology.] 31 ■ * ■ ^\ r -*. 4 ,-,^ . 242 PALEONTOLOGY OF NEW-YORK, 301. 2. CERAURUS PLEUREXANTHEMUS. Pl. LXV. Kigs. 1 a-n; and Pl. LXVI. Figs. I a - h. Ceraurvs pleurexantheinus. Gkeen, 1S32, Monograiih, pag. S4, fig. lU (Cast no. 33). Calymene? sjieciosus, Dalman Hisinger, Leth. Suecica, Suppl. '2, 1S40, pag. 6, pl. 39, fig. 2. — — Dalman, Palaeaden, p. 74 ; Vet. Acad. Handlingar, 1S2G, p. 28.'5, who quotes Trilobites in- detenninahis, Sternberg in Verhandl. des Gesellsch. des Vaterl. Museums in BohcMiie, pag. 85, tab. 1, fig. -5. Amiihion gelathiosits. Portlock, Geol. Rep. Londonderry, 1843, pag. 289, pl. 3, fig. 4 a, i, c. Compare Trilobites ignotits, Brongniart, Crust, fossiles, 1822, pl. 4, fig. 11. Calymene ? verrucosa, Dalman, Vet. Acad. Handlingar, 1 826, p. 285. Trilobites {Calymene!) verrucosa. Dr. Loven, Ofv. Vet. Ac. Forhandl., March 18-15, p. 52, t. 1, f. 5 a 6 c* Buckler crescentform, with a prominent connate articulation at the base, and the posterior angles extended into long curved spines ; eyes small, distant, sublunate, granulated (not reticulated ) ; glabella clavate, more or less convex, deeply foiu-lobed on each side, leaving the front one broader ; thorax with eleven articulations ; caudal shield with four ( scarcely five ) anchylosed articulations in the axial lobe, and three on each lateral lobe, the upper of these lateral articulations thickened and extended into a long curved spine, the others terminating in blunt points; surface entirely papillose or granulated, the buckler with scattered larger tubercles ; two ranges of small papillose tubercles along the central lobe, and three ranges of mammillary tubercles on each lateral lobe ; labrum ovate, attached to the front margin of the glabella by a straight suture. The above description comprises the most essential characters of this peculiar Trilobite, which is presented to us under a variety of obscure phases, no single specimen exhibiting all the essential characters. The whole surface, when perfect, is papillose. Upon all parts of the cephalic shield are interspersed small mammillary tubercles, and two similar ones on each articulation of the axial lobe, making two ranges of tubercles. Each articulation of the lateral lol)es, presents three large mammillary tubercles ; the first formed by an obli(iue furrow from the upper side of the articulation, downwards and outwards ; the third, by a furrow from the upper edge, downwards and inward, or toward tlie axis : the meeting of these furrows leaves above them the second, or middle tubercle ( see Plate Ixvi, figs. 1 a and 1 e). Tiiis remarkable feature is unknown to me in any other trilobite. The ovate labrum attached directly to the front of the glabella, is shown in Plate Ixv, fig. \ d e. From each uj)pcr angle of the labrum commences the facial suture ( more distinctly sliown in Plate Ixvi, fig. lac), which, proceeding to the eye in a slightly curving line, divides the oculiform tuljcrcle, and thence slightly ascending to the junction of the marginal fillet, it bends abruptly downwards. • I have referred to this species, wliicli appears to be a true Ceraurua allied to the C. pleurexanthennis ; and since its geological position is very similar, judging from the locality (Llandeilo), its occurrence is doubly interesting. trenton limestone. 243 Plate LXV. Fig. 1 a. A nearly entire specimen, with the maxillary portions obscure or partially removed. This is the orifjinal specimen upon which Prof. Green fonnded the Genus Ceraurbs. The buckler is partially crushed and obscured by soft shaly matter, and the oculiform tubercle very imperfectly preserved. The posterior prolongations of the buckler are distorted and obscure, as are also the spines proceeding from the caudal shield. Although very obscure, a careful examination shows that the structure of the articulations, form and lobes of the glabella, correspond wiiii the better preserved specimens represented in the succeeding figures. Fig. 1 J. A specimen of the same partially folded, with the buckler curved forward and the margin broken off The crust is partially exfoliated, so that the surface markings are not well preserved. Fig. I c. Front view of the buckler, showing the junction of the epistoma. Fig. I d. A large imperfect specimen of the same species, showing more distinctly the peculiar structure of the articulations. The buckler is imperfect, but still partially preserves the posterior spines. The caudal spines are broken off! Fig. 1 e. Lower side of the buckler of the last, showing the epistoma joined by a straight suture to the front of the glabella. Fig. 1 / A separated labrum, with upper margin broken off, being the form in which they are usually found in the rock. Fig. 1 g. A buckler, with the maxillae removed. Fig. 1 h, i. The glabellse of two large individuals. Such fragments are very frequently found, while perfect specimens are exceedingly rare. 1 i*. A magnified portion of the surface. Fig. 1 /;. A caudal shield, with the spines removed. Fig. 1 I. The spines of the caudal extremity, with a single articulation connecting them. View from the lower side. Fig. 1 m. The caudal shield, with the spines attached. This specimen preserves the characteristic fea- tures of this part of the fossil in great perfection. The spines are attached to the first segment only, which is enlarged and greatly expanded laterally, and, as it curves downwards, throws out a process above, to which the segments of the thorax are joined. 1 m*. A magnified portion of the surface. Fig. 1 n. A transverse section, showing the elevation of a segment, and the lateral extension of the articulations into fin-like processes. Plate LXVI. The specimens illustrated upon this plate were obtained after the previous plate had been engraved. Fig. 1 a. A fragment of a large individual, preserving the buckler and eight articulations of the thorax. The surface is beautifully and evenly granulated or papillose, with larger tubercles upon the cephalic shield, and mammillary tubercles upon the articulations. These are enlarged in the figures 1 b, c, d. Fig. 1 e. Front view of the specimen 1 a, showing the elevation of the oculiferous tubercles. Fig. 1 / One of these tubercles magnified. When magnified to this degree, they exhibit only rounded granulations. 31* 244 PALJSONTOLOGY OF NEW-YOKK. Fig. 1 g. The cephalic shield, represented in fig. 1 a; showing the separation of the maxillce y y at the facial sutures. Fig. 1 h. The right maxilla, separated from the cephalic shield, as it appears in a fragment of the lime- stone. Much confusion in regard to this species exists in the works of foreign authors, several distinct forms being erroneously referred to the same ; while the real one, which doubtless occurs in several localities, is referred to another genus. Capt. Portlock, though disposed to recognize and identify all American species, has failed in this instance, and his Amphion gelatinosus can scarcely be any other than our species. This difficulty has arisen in part from the obscure specimen from which Green's cast was made, the character of the buckler being very indistinct, though the nodulose articulations are well preserved. Emmrich, in his memoir, remarks that the Jitnphion gelatinosus of Portlock belongs to Phacops, a section of the Genus Calymene of Brongniart, having reticulated eyes. This is quite untrue, however ; for the eyes of Ceraums are peculiar, and quite different from those of Phacops, as they are from those of Calymene ; while the facial suture is similar in direction to the former, and the labrum, as in that genus, is attached by a suture to the front of the glabella. More recently. Dr. Loven ( id cit. ) lias attempted to prove the identity of Ceraurus, Odontopleura and Jlcidaspis ; but he has misapprehended the characters of the Ceraurus, owing to the obscurity of the model of Green. I shall hereafter be able to show that the Ceraurus is restricted to the lower epoch of our palteozoic strata, while Jlcidaspis {Odonto- pleura) is a genus continued into the lower and middle palaeozoic strata, and differing essentially from Ceraurus in many other particulars, as well as in the direction of the facial suture. I have given the numerous figures of this species, and of the parts usually found in the Trenton limestone, with a view of establishing the characters of the genus, and its clear distinction from other genera of Trilobites in the older strata. Notwithstanding all that is given, however, the entire characters of the species are not represented, as will be seen from the transverse view of a single articulation (PI. 65, fig. In), which is well preserved on the surface of a slab of limestone, showing the extended extremities, which bend abruptly downwards and curve slightly backwards, terminating in an obtuse point. Position and locality. This species, so far as known in New-York, is restricted to the period of the Trenton limestone. It is found at Middlcville, Trenton falls, Lowville and Wntertown, and is more rarolj' seen in localities in the Chaniplain valley. It is also known in several western localities and in Canada, showing a wide geographical range. The large fragment figured on Plate 66 is from near Cincinnati, Ohio. TRENTON LIMESTONE. ' 245 302. 3. CERAURUS VIGILANS. Pl. LXV. Figs. 2 a -A. Compare Entomolithus, No. 2, Linne, Vet. Acad. Handlingar, 1759, T. 1, fig. 2. Entotnostracites punctalus (Trilohus punctaltis, Brunn.), Wahlenskkg, Act. Soc. Sc. Upsallcnsisi, 1V21, Vol. viii, pag. 32, no. 7, tab. 2, fig. I. — — BnoNGNi.MiT, Crust, fossiles, 1S22, pag. 36, tab. 3, fig. 4. Tri/obites punctatus, Schlotheim, Nurhlra;.;e, IS23, Vol. ii, pag. 37, no. 23. Calymene punctata, Dalman, Vet. Acad. Handlingar, ls2G, pag. 233 &. 207, pi. 2, fig. 2 a 6. . '^ "i" — — HisiNGER, Leth. Suecica, 1S37, pag. 12, pi. I, fig. 6. y. — .' ? — MuncHisoN, ,Sil. System, 1830, pag. 001, pi. 23, fig. Sab. Amphion multisegmentatus, Pohtlock, Geol. Rep. Londonderry, lS-13, pag. 291, pi. 3, fig. 6. Buckler subcrescent-forni, with the posterior angles extended into long sharp spines, which, when perfect, reach backward to the coinmencement of the caudal shield ; entire surface of the buckler studded with strong tubercles ; glabella not lobed, front margin thickened and studded by two lines of tubercles ; oculiform tubercles subconical, remark- ably prominent, granulated ; facial suture as in the preceding species ; maxillary shield thickened and tuberculated at the margin ; labrum small, ovate, attached directly to the front of the glabella ; thorax with eleven articulations, the lateral lobes three times the width of the central lobe ; pleurae much extended ; caudal sliield elongated, the lateral lobes with nine simple segments, while the central lobe has twice as many ; every second segment of the central lobe of the thorax is^iiarked by a tubercle or short spine, and every third (or fourth) segment of the central lobe of the caudal shield ; alternate segments of the lateral lobes more or less distinctly tuberculated. - In all the specimens which I have seen, the body is partially contracted, and the lateral articulations bent downwards so that their terminations cannot be seen ; it is not improbable that some of them terminated in spinous processes, as in the preceding species. The posterior angles of the buckler, when perfect, terminate in long spines, which extend to the caudal shield, and are curved upwards at the extremity ; but these are frequently broken off, and the species might readily be mistaken. Surface of the buckler marked by pustular tubercles. The articulations are granulated, and every second one of the axial lobe of the thorax has a prominent tubercle or short spine, which is not often seen, however. The caudal shield closely resembles the figures cited above, though the glabella given by Wahlenberg as of the same species is totally different from our species, and probably not belonging to the caudal shield there figured. The great disproportion in the number of articulations of the middle and lateral lobes of the pygidiiun is very remarkable ; every third articulation in the central lobe is furnished with a short spine, which is usually broken off in all the specimens yet seen. Nearly all the specimens are distorted by being bent downwards just behind the buckler, while the latter is elevated and thrown sonaewhat backwards, giving it a remarkably prominent appearance.* * I have a specimen from Dudley, in England, marked Ca/ymene punctata, in which there are two caudal shields. 246 PALJEONTOLOGY OF NEW-YORK. Fig. 2 a. An entire specimen, preserving the posterior spines of the buckler. Fig. 2 b. Front view of the same, showing the elevation of the oculiferous tubercles. Fig. 2 c. A small specimen with the surface markings obscure. Fig. 2 d. Lateral view of a specimen, showing the extension of the extremities of the lateral articulations. Fig. 2 e. Caudal shield of a larger individual. Fig. 2f. An enlarged portion of the buckler of 2 a, showing pustulose tubercles, which appear much like the tubercles on the surface of Echinus or Cidaris, for the attachment of the spines. The oculiferous tubercle, under an ordinary magnifying glass, presents only small un- arranged granulations. Fi". 2 g. The caudal shield and a portion of the thorax enlarged, showing the tubercles upon alternate and third segments. Fig. 2 h. Profile of the same. Position and locality. This rare species occurs in the lower shaly portions of the Trenton limestone, being scarcely known except in the soft argillaceous beds, which admit of their nearly perfect preservation. I am indebted to Mr. Wadleigh, of Middleville, for several very good specimens. (State Collection.) 303. 4. CERAURUS'? PUSTULOSUS. Pl. LXI. Figs. 2 a, b. The specimen is a fragment, apparently of the lower side of the maxillary shield, with the prolonged posterior extremity. It is clearly distinguishable from the preceding species, by the large pustulose markings with a finely granulated surface between. It is not easy to decide positively regarding this fragment, and further discoveries may prove it to belong to the Genus Jlcidaspis, which in its surface marking is allied to Ceraurus. The margin presents some elevated tubercles or fine lines which are not represented in the figure. Fig. 2 a- The fragment, natural size. 2 i. A magnified portion of the same. Position and locality. This fragment was obtained from the higher beds of the Black- river limestone, near its junction with the Trenton limestone, at Watertown. {From Dr. Crawe.) very similar to the one under consideration, and the ditrerence of geological position renders it desirable to point out any difTerences of character. In the Dudley specimens, thougli not larger than ours, there are at least twenty-five segments in the middle lobe and eight or nine in the lateral lobe, every fourth articulation is tuberculated, and the tuberculations on the lateral lobes are nearer the axial lobe. The surface, also, appears not to have been as roughly granulated as in the Trenton species. Hisinger cites Calymene punctata as irom the more recent Transition limestone, and Murchison has given it from the Caradoc sandstone. There are doubtless two species referred to this name, and I have regarded the one under consideration as differing from the species of Wahlenberg, Dalman, &c., though closely allied to it. THENTON LIMESTONE. 247 304. 1. PHACOPS CALLICEPHALUS. Pl. LXV. Figs. 3 a-i. Compare Phacops Dalmanii, Portlock, Geol. Rep. Londonderry, paj. 2vi, pi. 2, fig. 1 a, b, c ; and pi. 3, fig. 7 2, pag. 14.5, pi. 4, figs. G, 7 a b c. — BuisBY, Ann. Lye. Nat. Hist. New-York, 1824, Vol. i, pag. 214, pi. 15, fig. 1. jViitlainia cotuentricn. E.4.T0N, Geol. Text-Hook, 1832, pag. 128, pi. 1, fig. 2. Cryptolithitx tcssellatus. Green, Monograph, 1832, pag. 74. Trinuchus caractaci. Murchison, Sil. System, lS3i), pag. 0.")9, pi. 23, figs. 1 a b c d. ^saphus seticornis, and A. cyllarus. Hisingeh, Leth. Suecica, Suppl. ii, 1840, pag. 3, pi. 37, figs. 2 and 3. Trinucleus caractaci. Hurmeistkr, 1S43, pag. Co, tab. 1, fig. 1. Compare Entomostracites granulatus, Wahlenberg, Act. Nov. Soc. Sc. Upsalensis, 1821. — — Brongniart, Crust. fo.ssiles ( figure alter Wahlenberg). Maphtis gramdattis, Dalman, Vet. Acad. Handlingar, 1820, pag. 238, tab. 2, fig. 6. — — HisiNGER, Leth. Suecica, pag. 14, pi. 2, fig. 4. Buckler semicircular or subcrescent-fonn, the posterior angles prorluced into ]ona; slender straight spines; glabella very prominent, finely granulated, produced posteriorly into a short spine ; checks prominent, finely granulated ; marginal fillet marked in front l)y three, four, or five rows of deep rounded pores or punctures ; these rows increase by one or two additional ones on the sides of the shield, and towards the lateral posterior angles are often irregularly scattered. The buckler or cephalic shield alone is figured here, as I have no specimen of the thorax or caudal shield from the Trenton limestone, thotigii llie buckler is often abundant. I iiave restored the specific name given by Eaton, adopting the generic name of Lhwyd given by Murchison. There is indeed no reason for a separation on account of the number of rows of pores, as they are variable, and the specimens are more often without the long spines of the buckler than otherwise. The specimen figured by Green, is one before referred to, as coming from the slates of the Hudson-river group, near Waterford, which at that time were regarded as almost non-fossiliferous. Though destitute of the small spines at the posterior angles of the buckler, it is specifically the same as those here presented, and doubtless identical with the figures of Murchison, though more doubt may be entertained as to its identity with those of Wahlenberg and Dalman. Fig. 4 a. The cephalic shield of this species, still preserving one of the slender spines from the posterior angle. The posterior spine of the glabella is broken off", though the fracture is not conspicuous. Fig. 4 b. Lateral view of the cephalic shield of a smaller specimen. Fig 4 c. The cephalic shield of a small specimen, in which the glabella preserves its posterior spine. These specimens present some variety in the number of rows of punctures in the border, and the same is true in many other individuals, showing that this chaiacter is not reliable for specific distinction. Position and locality. In the higher subcrystalline portions of the Trenton limestone, and sometimes in the more slialy part of the rock, the bucklers of this trilobite are abundant. The fragile thorax is very rarely preserved, and I do not recollect to have seen one in the limestone in the whole course of my investigations. It is found at Trenton falls, Middleville, Turin, Lowville, Watertown, Glensfalls, and many other localities of this rock. Although more abundant in the Hudson-river group, it is unknown in the intermediate Utica slate. [ Palaeontology.] 32 (State Collection.) 250 pai,;f.ontology of new-york. TRILOBITES OF THE UTICA SLATE AND HUDSON-RIVER GROUP. Plate LXVI. ( in part ). The important and characteristic Trilobites of these rocks are species which appear, though less conspicuously, in the Trenton limestone, and have been already noticed. The rule I have adopted, however, renders it necessary to speak of them here, giving- illustra- tions of specimens from these rocks. The most numerous forms are those of Calymene beckii and Trinucleus concentricus ; and the condition of the specimens in the shaly strata is so different from the same in the compact limestone, that both require illustration. Two or three forms appear in these rocks, which are thus far unknown in the limestones below, and which are probably peculiar to this period, becoming developed only after the com- mencement of argillaceous deposits. 297. 2. CALYMENE BECKII. Pl, LXVI. Figs. 2 a-k; and Pl. LXVII. Figs. 4 a, b, c, d, e. Reference pag. 2^1, pl. 64 of this report. Much confusion has arisen respecting this species, which is abundant in the Utica slate. It was first described by Prof. Eaton, under the name Brongniartia, from imperfect specimens of the cephalic shield, in the calcareous beds of the Utica slate, at Coldspring, Montgomery county. These specimens are more convex than those in the softer slate, and their true character is not obvious on a cursory examination. Prof. Green substituted the name of Triarthrus for that proposed by Prof. Eaton ; still regiyding the small imperfect cephalic shields as the entire animal. Dr. Harlan, in correcting this error of Eaton and Green, described the buckler as destitute of oculiform tubercles ; and I have, myself, fallen into the same error in describing as distinct species two nearly entire specimens, owing to the absence of the maxillary shields in one, and their partial preservation in the other.* * Silliman's Am. Jour. Science, Vol. xxxiii, p. 137. UTICA SLATE ANU HUDSON-RIVKK UROIIP. 251 The buckler of our species bears considerable resemblance to tli;it of specimens of Olenus gibbosus from Sweden ; but llie true Olenus, as in Paradoxides, has thn facial suture terminating at the posterior margin of the buclvler, distant from tlie angles, while in this one it terminates at the angles as in Cahjmene. Tiic labrum found in the slate associated with this species, has also the form of liiat organ in Calymene senaria ; and taking these two facts in connection, I have preferred to refer the species to Calymene, since it is more nearly related to other species of that genus than to the Oleni. There is still some little difficulty in determining the number of articulations of the thorax, since the greater number of specimens are imperfect ; and in a single large specimen there appear to be fourteen or liftpen. This fact indicates an increase in tlu; number of thoracic rings with age, a character which Emmrich has given of the Olenus. The articulations of the lateral lobes are marked by a simple straight groove extending their entire lengtli, and terminate in an obtuse point, unlike those of the true Oleni as represented by various authors. On account of these ciiaracters, it is impossible to refer the species satisfactorily to the Genus Olenus, though in some of its characters it evidently forms a link between that genus and Calymene. Farther investigation of this species may develop characters sufficiently distinct from Calymene to establish the Genus Triarfhnis, which was proposed witli a very imperfect knowledge of the entire animal. The most prominent character of this species, distinguishable in the segments of the thorax, are the tubercles or short spines which mark the centre of the axial lobo, and are usually more or less distinctly preserved under all circumstances. No other trilobite in the lower strata possesses this character ; the Ceraurus pleurexanthemus having a double row of less prominent ones, while in the C. vigilans every second or third segment only is marked in this manner. In order to illustrate this species, and, if possible, to clear up the difficulty and obscurity attending it, I have given numerous figures of its different parts, and of the same parts preserved under different circumstances and in different materials. Fig. 2 a. An entire specimen, with the exception of the maxillary shields, which arc separated at the facial suture, leaving the cephalic shield in the usual form. Tin' crust of the central lobe of the thorax is removed, obliterating the tubercles Fig. 2 b. An imperfect specimen, witli the maxillary portions partially preserved, but separated at the suture and pressed downwards. Fig. 2 c. The thorax and caudal shield, preserving the crust with the tubercles upon the middle lobe, in a very perfect manner. Fig. 2 d. The cephalic shield, with the maxillary portions separated at the facial suture. Fig. 2 e. The cephalic shield entire, but so much compressed that the eyes are obh'terated. The posterior angles are too much rounded in the figure; in other respects, the true form of the buckler is represented. Fig. 2/ The cephalic shield preserved in compact calcareous stone. This specimen is from the same locality, and very similar to the one on which Eaton founded the Genus Brongniartia. Fig. 2 ^. A larger specimen, in compact limestone, preserving a more convex form in all its parts. 32* 40i PALJEONTOLOGY OF NEW-YOKK. Fig. 2 h. A small individual, preserving the thorax and the maxillary portion of the buckler, the glabella being separated. Specimens of this kind are not rare among the young individuals. Fio'. 2 i. The maxillary shields, as they frequently occur in the slate, separated from any other part of the fossil. The position and partial form of the base of the eye is clearly distinguishable. Fig. 2 k. A single maxillary shield of this species. It is impossible, from the slender and fragile nature of these portions of tlie fossil, to decide whether the suture continues entirely across the front of the glabella, or is interrupted as in other species of Calymene. The specimen 2 i, shows a continuous slender fillet in front; but this may be joined to the lateral portions by sutures, since the specimen fig. 2 k terminates as in Cahjmene senaria. Position and locality. It has already been observed that this species is more abundant in the Utica slate than elsewhere, being in fact the only trilobite usually seen in that rock. Large surfaces of tiie lamina; are often almost entirely covered with the fragments and more or less perfect individuals. The most prolific localities are Coldspring, on the Erie canal, Montgomery county ; Oxtungo creek, above Fort Plain ; Martin's Hill, near Amsterdam ; Turin, Lewis county ; and less abundantly at Utica and numerous other localities. (State Collection.) Plate LXVII. Jltops trilineatus. Emmons, Tac. System, pag. 20. — — Id. Agr. Report, pag. 64. Fig. 4 a. The buckler, with a few of the articulations of the thorax. The specimen is very much compressed, and the crust removed. It is imbedded in a gritty micaceous slate, and in such a condition as to render it somewhat obscure. The form of the buckler, with the lobate character of the glabella, leave no doubt of the true nature of the fossil. Fig. 4 A. A specimen of the same fossil, presenting nearly the entire length of the individual ; the form and markings of the buckler are obscure, but still visible, and evidently identical with the fossil from the Utica slate. Fig. 4 c. An iuiprcssion of the body of this fossil, showing the indentations produced by the short spines upon the back. Fig. i d. A. portion of the same enlarged, showing the impressions of the fine granulations of the crust. Fig. 4 e. This fragment preserves an impression of a part of the central and one lateral lobe of this species. ( See Emmons' Tacnnic System, pag. 19, pi. 2, fig. 3; and Agricultural Report, pag. 63, pi. 14, fig. 3. ) These specimens are all in the thinly laminated, folded, and partially altered slates, on the east side of the Hudson. Tire occurrence of these fossils is sulhcient evidence of the age of the strata, without the evidence furnished in the structure of the country as presented in the sections. This species likewise occurs in the unaltered slates of the Hudson-river group, in Lewis, Jeficrson and Oswego counties. .m i 1 'ITICA SLATE AND HUUSON-RIVEK UKOUl'. 25c 308. 4. CALYMENE {Species undetcrmmed). Pl. LXVr. Fi',M. 3 a, ft. Caudal shielfl witli sevcMi or more articulations in the lateral lobes, and ten in the middle lobe ; articulations of the lateral lolies of the thorax and caudal shield with a distinct groove extending nearly their entire lengtli ; extremities obtuse ; lateral lobes nearly once and a half the width of the middle lobe. The width of the lateral lobes of the thorax, compared with the middle lobe, is much greater than in Calymene beckii, and somewhat greater than in C. senaria. The continuous, nearly direct, groove in the articulations of the lateral lobe, is different from the same in C. senaria, and may perhaps prove a sufficient distinction to identify fragments of the two species. The two fragments figured are the only parts of the fossil yet observed, and from these the crust is entirely removed, so that no aid in distinguishing the species can be obtained from the surface markings. Fig. 3 o. A part of the thorax, preserving eight or nine articulations. , "' . ■ Fig. 3 b. The caudal shield, with a kw segments of the thorax. Position and locality. These specimens were obtained in the Utica slate, near Canajo- liarie, Mohawk valley. The Calyme7ie beckii occurs in the same locality. {From Mr. Everett, Principal of the Canajoharic Academy.) 309. 5. ASAPHUS? LATIMARGINATA (71. *;>.). Pl. LXVI. Figs. A a,b. Compare Aaaphus tyrannus, Murchison, Sil. System, 1839, pag. CG'2, pl. 25, fig. 1 a 6. Caudal shield with fourteen articulations in the lateral lobes, and ai)out the same number in the middle one ; the posterior articulations of the latter lobe join the axis in an acute angle, and all terminate in a fiat border; surface ( of exfoliated portions) marked by imbricating lamellose striae ; outer surface of the crust finely punctured. The fragment of a caudal shield of a much larger specimen ( fig. 3 6), was found in the same stone as the other, and, from its surface markings, doubtless belongs to the same species. The articulations are narrow, as in Asaphus tyrannus, and terminate in a broad flat border ; it is impossible, however, to decide that it is identical with that species. It also bears some analogy with the fragment found in the Birdseye limestone, but on comparison proves clearly distinct. V, .. 254 PALEONTOLOGY OF NEW-YOKK. Numerous fragments of articulations of the thorax were found with the specimens here figured. In one of these, an articulation of tlie lateral lobe is marked by a broad groove, extending about two-thirds of its length from the axis; beyond which, it presents a broad flattened surface, sharpened upon the upper edge, and obtuse at the extremity. Figf. 4 a. The caudal shield of a small individual. Fig. 4 b. A fragment of the lateral lobe of the caudal shield of a larger individual. Position and locality. This species has been seen only in a single fragment of slate, from near Watertown, Jeflerson coimty. I should not have ventured to figure it in this place, since there is some little doubt as to its precise locality ; but that the same fragment contains one or two other peculiar fossils, known only in the slates of this period. (From Dr. I. B. Crawe.) 43. 1. ISOTELUS GIGAS. Pl. LXVI. Fig. 5. Reference pag. 231, pi. 60, 61, 62 and 63 of this report. I have obtained from the Utica slate, in the Mohawk valley, the large labrum here figured. The dimensions are twice as great as any other specimen I have seen ; and judging from this circumstance, the animal must have lieen at least eighteen inches long. The distance between the extremities of the processes is less, and these parts are proportionally^ shorter than in specimens from the Trenton limestone ; but these differences do not appear to be sufficient to found specific distinctions. Fragments of other portions of this species are often found in this slate, and also in the shales of the Hudson-river group ; but the animal does not appear to have existed in any considerable numbers, after the deposition of the Trenton limestone. HUDSON-RIVER GROUP, . 255 TRILOBITES OF THE HVDSONRIVER GROUP. 307. 1. TRINUCLEUS CONCENTRICUS. I'l. LXVII. Fiis. 1 a-li. Also Pl. LXV. V\'i. 1. The specimens from the slates of the Hudson-river group are more flatleneil tlian those from the Trenton limestone. In a large numl)er of specimens examined, there are four rows of punctures in front of the buckler, while a few have but three rows ; on the other hand, those with four rows are rare in the Trenton limestone, while those witli three rows are the prevailing form. This difference, however, cannot be regarded as essential, for in a few instances there are five rows, and very frequently five or six rows on the maxillary margin, near the posterior termination of the buckler. The specimens in the Hudson-river group rarely preserve the posterior spine of the glabella, but it is shown in fig. 1 d, and is never wanting except from accident. The long spines from the posterior angles of the buckler correspond in tlie specimens from the two rocks. The thorax consists of six free articulations, the lateral ones being bifurcate or grooved ; the caudal shield has seven segments in each lateral lobe, and about fourteen in the central lobe. The crust is exceedingly thin, almost always separating; and when preserved in the shaly strata, rarely shows any surface markings. The animal had the power of contracting or folding itself, at least to a certain degree, though this does not apjjear to have been its habit. Fig. I a. A large individual, destitute of spines upon the posterior angles of the buckler and glabella. The border in front oi the glabella has three distinct rows of punctures, four in front of the cheeks, and five on each side, with six or seven near the base. Fig. 1 b. The thorax and caudal shield enlarged, to show more clearly the character of the segments. Fig. 1 c. A smaller specimen, preserving the spines of tiie buckler. There are four rows of punctures in front, and six on each side of the buckler. Fig. 1 d. The buckler, preserving the posterior spine of the glabella. These specimens are from the soft shales in the upper part of the Hudson-river group, at Loraine. Fig. 1 e. Fragments of the cephalic border, showing a variable number of rows of punctures in front; one having five, with seven or eight at the posterior margin. Fig. 1 /. A portion of the marginal fillet, where the crust is partially removed, showing the little studs or points which fill these pores from below. 256 PALEONTOLOGY OF NEW-YORK. Fig. 1 0-. A fragment of a large buckler, having but two distinct rows of punctures in front of the glabella. Fig. 1 h. A portion of the thorax and caudal extremity, from the glazed slate, at Waterford. The long spine appears as if attached to the caudal extremity ; but it is scarcely in a direct line with the axis of the specimen, and is not quite symmetrical on the two sides at its base. I am, therefore, inclined to regard this as a spine from tlie buckler, which has been accidentally placed in this position. I have not yet been able to find any marks of specific distinction among these fossils, though I have examined more than one hundred nearly perfect specimens, and as many frao-ments, from the slate and limestone. The small spine-like process at the base of the glabella has not been heretofore observed, but it will be foimd to exist in all perfect speci- mens ; the cause of its absence is fracture, which may often be obscure or indiscernible. I am indebted to Dr. Emmons for an opportunity of examining a beautiful collection of specimens of this species, from the shales of the Hudson-river group, at Loraine. Many of the small slabs are completely charged with them, and several hundreds were obtained in the space of a few feet. Position and locality. This species is found throughout the rocks of the Hudson-river group, occurring in the lower part of the same at Turin and Marlinsburg. At Loraine and Pulaski, this fossil occurs in the higher parts of the group ; and at Waterford, near Cohoes falls, in the glazed and plicated slates of the same group. It has likewise been found in one or two places in the Mohawk valley, in a similar position. (State Collection.) 310. ]. OLENUS ASAPHOIDES. Pl. LXVII. Figs. 2 a, 4, c. Elliptocephalus asaphoides. Emmons, Tac. System, 1811, pag. 21, fig. 1,2, 3. — — Id. Agr. Report, 1816, pag. 05, figs. 1. 2, 3. Compare Asaphiis (Ogygia) Buchii, Brongniart, Crust, fossiles, pag. 20, pl. 4, figs. 2 a i. Asaphus Buchii, Murchison, Sil. System, pag. 6(52, pl. 2.5, fig. 2. Ogyi(ia (Jisaphits) Buchii, Burmeister, pag. 69, pl. 1, fig. 2. Olenus of Dalman, Burmeister, &c.* Buckler semielliptical or subcrescent-form, with the posterior margins produced into sharp spines ; eyes indistinctly marked ; glabella lobed ; direction of the facial suture as in * The species under consideration is either an Olcttus or Ogygia, as the genera of this class of animals are now defined, and I therefore arrange it with tlie former for reasons to be given. The name El/iplocephalus could scarcely be admitted, since the Ellipsocephalus of Zenker is so well known in its application to a very distinct generic form. flDDSON-lUVEK GROUi>. 257 Olenus ; thorax trilobate, the longitudinal furrows not defined ; segments of the middle lobe moderately broad and flat, those of the lateral lobes grooved along the centre, suddenly bent backwards near tlic extremity, and pointed : surface markings obliterated. The specimen, which is imperfect, preserves five and part of the sixth articulations only, upon the middle and one lateral lobe. The crust appears to have been very thin, and the whole specimen is very much compressed. The elliptical central portion of the buckler, on which the Genus EUiptocephalus is founded, appears to be due in part to the outline of the eyes and the line of the facial suture. This character is not so distinct in the specimen 2 6. The specimen 2 o, though very indistinct, clearly presents the lobate character of the glabella, which is margined in front, as Well as laterally, by a broad coriaceous margin. The form of the buckler, its prolongation posteriorly into spines, the form of the glabella, and the character of the' articulations, the grooved lateral segments, and their abrupt bending backwards with pointed extremities, correspond very closely with Jlsaphus ( Ogygia ) buchii. Tiie proportional width of the middle lobe, liowcver, is much greater ; and the course of the facial suture is different, so far as can be ascertained. The buckler is more elongated than in Olenus spinidosus, which in some respects it resembles.* Fig. 2 a. An imperfect cephalic shield, with several articulations. Fig-. 2 6. A smaller imperfect cephalic shield. Fig. 2 c. A fragment of one of the lateral articulations of the thorax. Position and locality. This species was found associated with Calymene heckii, and a few other undetermined fossils, in the dark laminated micaceous slates at Greenwich, Wasiiing- ton county. The position of these slates has already been alluded to ; the particular locality is about tliree miles northeast of Bald mountain, wliere the lower limestones are clearly exposed, and upon which these plicated and partially altered slates repose. (Cabinet of Prof. Emmons.) •This species, with CaJymene beckii {Jltops trilineatus), are those given by Dr Emmons as the characteristic trilobites of tlie Taconic system. I caunot admit the Atops to be distinct from Calymene beckii; and though the other form is doubtless new, it evidently belongs to a lower silurian type. Tlie discovery of a new species in our older rocks, whether among the disturbed or horizontal strata, is not a matter of surprise, for sucli discoveries are of frequent occurrence. I have already given my own views in regard to the position of these rocks, and I see no reason to change this opinion. Supposing the existence of a system of strata below the Potsdam sandstone, of which we have no proof, we might fairly infer that the wide interval between the deposition of those strata and the Hudson-river group would give us forms of animal life more widely difTerent than these examples offer. The great analogy between the latter species and the succeeding one, which is from strata scarcely disturbed, shows how similar were the forms of two supposed epochs. [ PaljEontolooy.] 33. 258 PALEONTOLOGY OF NEW-YOEK. 311. 2. OLENUS UNDULOSTRIATUS (m. *;?.)• Pl. LXVII. Figs. 3 a, b. Compare Olemis spinulosus, Dalman. Buckler semielliptical or sublunate, the posterior angles extended into diverging spines ; eyes lunate ; glabella (apparently not lobate) marked by fine rugae ; facial suture extending from the margin of the cephalic shield, in front of the eye, to the base of the same, distant from the angles ; articulations slender, those of the lateral lobes grooved. The single fragment figured, is all that has been seen of this species. The character of the buckler, form of the eye, and direction of the facial suture, induce me to refer it to the Genus Olenus. It is, in many respects, analogous to the preceding species, but is too obscure to decide whether the glabella is lobed or not. The segments of the thorax are imperfect, and the extremities are not preserved. Fig. 3 a. The fragment, natural size. Fig. 3 A. A part of the same enlarged, showing the course of the facial suture, and the rugose striated glabella. Position and locality. This specimen was obtained at Snakehill, Saratoga lake, in the soft olive shales, associated with other species belonging to this group. {State Collection.) 312. 1. AGNOSTUS LOBATUS (n. sp.), Pl. LXVII. Figs. 5 a -/. Minute, trilobate, with a narrow border around the base and sides ; middle lobe often with a small tubercle near its larger extremity. This species bears considerable analogy to the Swedish specimens from a similar geo- logical position, but they are not identical. Our species is always smaller, and I have never seen the small node or tubercle at the base of the central lobe; but it presents a similar character on the other extremity. All our specimens have the appearance of the caudal shield of a small trilobite, and two or three individuals are apparently articulated. Figs. 5 a, b. Individuals of the natural size. 5 c, d. The same magnified. Figs. 5 e, /. Specimens sliowing an articulation of the lobes. Position and, locality. This pecidiar little fossil has been found only in some calcareous beds, intercalated with the shales of this group, one mile east of Troy. I am indebted to Dr. Skilton of that city for good specimens of the same. (State Collection.) HUDSON-RIVER GROUP, ADDENDUM TO THE TRILOBITES. 259 Among several western species not included in the previous descriptions, I introduce the following^, for the purpose of illustrating (lie characters of a fjcnus proposed l)y Mr. Conrad, and of showing a new form associated with several well known Trenton species, in the lower limestones of the West. Genus THALEOPS (Conrad). " Ovate, profoundly trilohed, lateral lohes wider than the middle lohe ; buckler lunate, with very remote oculine tubercles, not reticulated; abdomen with ten articulations; ribs witliout grooves, and not alternated in size ; outer half of lateral lobes suddenly depressed ; post-abdomen without rilis or grooves, and profoundly trilobed." I am not able to perceive tiie essential difference between this fossil and Ill-T-nus, of which it possesses all the characteristics, in the number and character of the articulations of the thorax, in the cephalic and caudal shields, and in the direction of the facial suture. 313. 1. THALEOPS (ILL^NUS) OVATUS. Pl. LXrV'II. Kiss. 6 a, b. TVialeops ovata. Conrad, Proc. Acad. Nat. Sci. Philadelphia, Vol. i, 1S43, p. 332. . " Obtuseljr ovale ; surface minutely punctate ; head very wide, lunate, involuted ; eyes very prominent, rounded, smooth, placed on a line with the angle in the middle of the side lobes; ribs flattened, smooth, without a border at the extremities, where they are rounded and not expanded ; post-abdomen with the middle lobe convex, rounded and well defined at the extremity; inferior margin obtusely rounded. Length two-tiiirds of an inch ; width of the buckler three-quarters of an inch." This species is clearly distinct from either of those previously described, in tiie pro- portional width of the lobes of the thorax ; and it is remarkable for the trilobate cluuacter of the caudal and cephalic shields. The outer surface of the crust is punctate, and not striated, as in several other species. The eye is remarkably prominent, and somewhat truncato-conical, apparently smooth to the naked eye, and presenting a finely punctate surface, only, under the magnifier. This species is associated with another species of IlltEnus ( /. crassicauda ? ), Ceraurus pleurexanthemus, Phacops callicephalus, or an allied species, as well as other well known Trenton limestone fossils. Fig. 5 a. The specimen of the natural size. Fig. 5 i. A part of the cephahc shield magnified, showing the punctures and the course of the facial suture. 33* 260 PALAEONTOLOGY OF NEW-YORK. Position and locality. This species is found in the lower limestone at Mineral point, Wisconsin. The association of numerous other fossils known only in the Trenton limestone or its representative, leave no doubt of the true position of the rock. {Cabinet of Mr. Conrad.) In addition to the preceding species, there are several others described by Prof. Green, which I have not examined, except in the plaster models, and cannot therefore describe them satisfactorily. These are the Asaphus tetragonocephalus, Ji. astragalotes, and A. onicropleurus, with one or two other doubtful ones. I shall endeavor to give figures and descriptions of these in a supplement to this work, after having examined the originals. There are one or two other species heretofore erroneously referred to the Trenton limestone, which arc now known to be restricted to the higher limestones. The strata of this period have been too little examined at distant localities, to enable us to speak with certainty of the geographical distribution of the Trilobites ; but a very large proportion of the species described are known at various localities within New-York, and in Ohio and Kentucky in the west and southwest ; in Canada on the north, and in Wis- consin on the northwest. Several of our species are evidently identical with those of the lower strata of Europe, and more particularly of England, Ireland and Sweden. It is interesting to observe how similar are the Trilobites of our lower strata with those of the same period in Ireland, given by Capt. Portlock, in his Geological Report (on Londonderry, and parts of Tyrone and Fermanagh ) . It is evident that among the prevailing forms, those which are identical with our species are more numerous than they are in England or upon the Continent ; thus assimilating the ancient fatma of the western extremity of Europe more nearly with that of the new world. Among the most numerous forms of our lower strata, we may mention Isotelus and Trinucleus, which are prevailing forms in Ireland. The Genus Ampyx, which is typical of the lower silurian rocks of Europe, was unknown among us till obtained from the eastern prolongation of the slates of the Hudson-river group in Canada, by Mr. Logan. In like manner Olenus and Ogygia, which have been reckoned among the doubtful genera of our older strata, appear to have existed in the eastern extension of the same, while they are quite unknown at the west. Other similar changes may be noticed in tracing the geographical distribution of the genera of Trilobites, both in tlie lower and upper silurian strata. In the present state of my knowledge on this part of the subject, the species here figured, or the Trilobites of the lower silurian strata, embrace about one-third of the species known below the Carboniferous period. In this remark, however, I intend to speak prin- cipally of the rocks of New-York, and those portions of the adjoining Slates which I have examined. It is impossible to say how far this proportion may be varied by further discoveries l)oth in the older and newer strata, but it is not iiuprol)able that it may continue very nearly the same ; and tliat the three great periods into which these strata are divided, present almost an equal lumiljer of crustaceans. UTICA SLATE AND HXnDSON-RIVER GROUP. 261 FOSSIL PLANTS OF THE UTICA SLATE AND HIDSON-RIVER GROLT. We find in tliis group several well marked species of marine plants, with other forms simulating, if not actually, organisms of tliis class. The prevailing forms are similar to tliose of the preceding strata, but the same species have not been recognized. Tlie nature of the sediment, and tlie condition of the ocean bed, were favorable to tiie development and growth of this kind of vegetation; for we find, in almost every locality, evidences of its existence. As our researches have been principally directed to the discovery of animal fossils, little examination has been made in situations most favorable for the preservation of these plants ; and we may anticipate a very large accession to the number of species, when careful explorations are made. The species already obtained show a considerable variety of form, and it is evident that we are but commencing our knowledge of the ancient marine flora. The two following species appear to be quite new, and to require a generic designation. Genus SPHENOTHALLUS. [Greek, (r^*iv, a wedge, and ^aXXo;:, a branch or frond ; in allusion to the form of the leaves.] Character. Plant consisting of a stem, with diverging wedge-form leaves, or of detached leaves having this form. Leaves apparently succulent or thickened, and sometimes sub- coriaceous. It will probably be found that plants of this character are restricted to Silurian, and perhaps Lower Silurian strata. , ■ '■ 314. L SPHENOTHALLUS ANGUSTIFOLIUS ( n. sp.). Pl. LXVIII. Fig. 1. The specimen is a fragment, consisting of a stipe or stem, to which are attached elongated narrow cuneiform leaves. These leaves appear to proceed in tufts, and are accompanied by other smaller and narrower ones about their base. The stem presents no distinct markings, though there are several obscure impressions which may have been the point of attachiuent for leaves. The leaves are obscurely striated, though nothing like a veined structure can be distinguished. The fragment has much the appearance of the terminating portions of the Calamites ; and it is diflScult to believe that it is not a land plant, though in a position so far below where anything of the kind has heretofore been discovered. Position and locality. The specimen figured, with another obscure fragment, were obtained from an authentic locality, between the village of Canajoharie, on the Mohawk, and Schoharie village, by Mr. Lyman Wilder, of Hoosick falls.* • I am thus particular in stating the locality, and my authority for the specimens, though the succeeding species serves to establish the fact of its occurrence in this position. 282 PALEONTOLOGY OF NEW-YORK. 315. 2. SPHENOTHALLUS LATIFOLIUS (w. 5;j.). Pl. LXVIII. Figs. 2 a -f. Leaves broadly cuneate, somewhat (hickened at the outer margin, and truncate at the lower extremity ; surface obscurely striated. The specimens are often marked on one side by a ridge or midrib along the centre, and sometimes transversely wrinkled. These leaves all appear to have been thick and succulent, like the Fuci. A large number of specimens have been seen, but in no case has one been discovered where the leaves are attached to the stem. Fragments of similar substance are often found with these leaves, which may have been parts of the stems of this species. The specimens present a dark carbonaceous surface, contrasting with the greenish shale in which they are imbedded. Fig. 2 a. A leaf nearly entire, showing a depressed line along the centre. Fig. 2 J. A similar leaf, with a sharp ridge along the centre. Fig. 2 c. A leaf of a narrower and more elongated form, with a broad ridge along the centre. Fig. 2 d. Another fragment, with a ridge extending a part of the length. Fig. 2 e, / Fragments of what may have been stems of this plant. Position and locality. This species occurs in considerable abundance near Schoharie, in the bed of the creek, in the central part of the Hudson-river group. I have not seen it in any Otlier locality. (State Collection; Cabinet of Mr. Gebhard.) 316. 4. BUTHOTREPHIS SUBNODOSA ( n. sp. ). Pl. LXVIII. Figs. 3 a, b. Compare Fucoides antiquus, Brongniart, Hist. Veg. fossiles, Vol. i, pag. 03, tab. 4, fig. 1. — — HisiNGER, Leth. Suecica, 1837, pag. 106, pl. 31, fig. 3 a. Frond compressed, branched ; branches opposite or alternate, subnodulose or vesicular, obtuse at the extremities. This species is common in the shaly sandstones of the Hudson-river group, in Lewis county. It bears considerable analogy in some of its varieties with the species cited above ; and its associations with the Graptolites of the older shales in Sweden, are very similar to its association in the rocks of New-York. It differs from the slender species of the Trenton limestone in the branches being shorter and subnodulose, and approaches more nearly to the species of the Clinton group. Figs, 3 a, b. Figures of imperfect specimens, illustrating the prevailing form of tlie species. Position and locality. This species is common in the central part of the group, at Turin and Martinsburgh, Lewis county ; at Loraine, Jefferson county ; and at Pulaski, Oswego county. ( l^tate Collection ) UTICA SLATE AND HUDSON-KIVER GROUP. 263 317. 5. BUTHOTREPHIS ? FLEXUOSA. Pl. LXIX. Figg. 1 a, b, c. Fueoides rigida & flexuoaa. Kmmons, Tac. System, 1S44, pag. 07, pl. 5, figs. 2 & .3. — — & — Id. Agr. Report, 1816, pag. GO, pl. 17. Frond compressed, .somwliat irregularly branched ; steins and brandies extremely compressed. This species presents much variation of character, owin<^ in part to tlie condition of the slate in which it is iml)edded. The two species of Dr. Emmons are not separable by any established characters, and wi; tinil lumierons intermediate forms. The specimens usually consist of a thin carbonaceous film upon the surface of the soft slate ; and slabs of several feet square are often nearly covered with fragments, which appear to have been of a less succulent character than most of the preceding species. This is one of the species regarded by Dr. Emmons as typical of the slates of the Taconic system, but I can find no evidence to support this assumption. The locality, though con- taining no characteristic fossils of the Hudson-river group, is surrounded by authentic exposures of these rocks, and the lithological character is the same. Further examination will doubtless enable us to obtain this species in other localities of the group. Fig. 1 ffl. A large fragment, with numerous branches or leaves. The specimen appears to have been long macerated before it was imbedded. Fig. \ b. A. specimen in the same condition as the last, with the branches less diverging. Fig. 1 c. A fragment of stone, with two smaller specimens retaining more of the original substance of the plant. Position and locality. In the slates of the Hudson-river group, M'Arthur's ([uarry, Jacksonj Washington county. (^""'^ Cuihciion.) ' - ''■ - 318. 5. PAL.f:OPHYCUS VIRGATUS (71. i-;;.). Pl. LXX. Fig. 1. This species is only seen in fragments of long rigid stems, of nearly equal diameter. It appears to have been succulent or tubular, and is always compressed in the stone. Fractured or weathered surfaces of the arenaceous shales often present great numbers of these fragments, imbedded in great confusion. The species bears some analogy to the P. simplex of the Trenton limestone ; but it is impossible to indicate characters either to assimilate or distinguish them. It can be readily identified in the rock, from its resemblance to llattened fragments of stems of succulent plants. , , Position and locality. This species is abundant in the shales of this group, in the neigli- berhood of Union village and Salem, in Washington county. (State Collection.) 264 HL^ONToLOGY of NEW-YORK. 319. 6. PAL^OPHYCUS [Species undetermined). Pl. LXX. Fig. 2. This species occurs in short, small fragments, often quite covering the shaly laininee in some parts of this group. It appears to have been a succulent plant; but no definite character can be assigned to it in the present state of our knowledge. The specimens figured are in a fragment of slate, presenting the usual aspect of the species. It is often found in smaller and in larger fragments, both covering the surfaces and penetrating the thin arenaceous layers. Position and locality. In the central portions of the group, near Rome, Oneida county ; and in Lewis and Oswego counties. (,State Collection.) 320. 1. GORDIA MARINA.* Pl. LXXI. Figs. 1, 2. Gordia marina. Emmons, Tac. System, pag. 67, pi. 1, fig. 2. — — Id. Agr. Report, pag. 68, pi. 14. I have given this peculiar form, though doubting whether it be organic. An examination of two specimens shows the slightly elevated ridge to be thoroughly incorporated with the stone on one side, and appear as if they had filled slight depressions in the soft shales beneath. The form and meanderings of this body are not unlike the tracks made by Melania and other aquatic and marine shells of the present day ; and I am, therefore, inclined to refer it to such a cause. Examined with tliis, or the other view, it does not detract from the interest attached to this singular marking upon the surface of these ancient strata. I have given figures of two specimens, in which the exact course of the elevated ridge is preserved. Position and locality. These specimens occur in the same position, and at the same locality, with those forms described on Plate LXIX, from M'Arthur's quarry, Jackson, Washington county. In addition to the forms here given, and those which are unequivocally of vegetable origin, there are others in which it is impossilile to determine their true character. After examining a considerable number of specimens of this kind, I have decided to omit them all, believing that an attempt to indicate species and genera where constant characters are wanting, will be followed by a multiplication of species of which the individuals described would be the only representatives ; an occurrence that can be attended with no good results to the science. • I have used the generic term Gordia in this instance, though aware tliat tlie similar name of Gordius will preclude its final adoption among naturalists. a. UTICA SLATE AND ilUDSON-RIVEH GROUP. 205 GRAPTOLITES OF THE UTICA SLATE AND HUDSON-RIVER GROUP. Tlie fossils of (his genus are numerous in many localities of tlie Utica slate, as well as in the succeeding greenish or olive shales. In the same shales and slates along' the Hudson river, they are more numerous, hoth as individuals and species, than in any other part of the State, or perhaps of the Continent. This genus, which recently contained Init a few species, has become so augmented that it now numbers not less than twenty distinct forms. In consequence of these fossils being usually imbedded in shale, and often extremely compressed, some doubt of their true nature has been entertained, and by some authors they have been j)lnced among plants. When imltedded in calcareous matter, they often preserve their original form and proportions, and reveal more cleaily their true character. In tliis condition, they show a more close analogy with the Linnean ViRGULARiA than with any other among living forms. This opinion has already been advanced by Dr. Beck of Copenhagen ( Murchison, Sil. System, p. 695 ) ; and an inspec- tion of the figures of G. bicornis, from specimens in limestone ( Plate LXXIII, figs. 2 7n.andm'), will sustain this view. Judging from this and several other well preserved specimens, all the Graptolites possessed a semicalcareous body with a corticiform covering ; which latter, entirely compressed, is all that is usually preserved in the slates. 321. 2. GRAPTOLITHUS PRISTIS. Pl. LXXII. Figs. 1 a-s. Piioiiotus pristis. Hisinger, Leth. Suecica, 1S37, pag. Ill, pi. 33, sup. fig. 5. Compare Graptolithus foHaceus, Murchison,' Sil. System, 1839, pi. 20, fig. 3. "Linear, straight, scarcely a line broad, compressed ; racliis central, capillary ; both sides with broad acute teeth." Tliis description of Hisinger corresponds precisely with the most abundant and widely distributed species of this genus wiiicii we have in the older slates. Tlie species occurs in small short fragments, and in forms which appear to be nearly entire, having a length of two inches. When the specimens are flattened, a central capillary axis is very perceptible, extending the entire length. In some specimens where the serrated portion is removed, * PoBTLocK is inadvertently cited as authority for this species, on page 79 of tliis volume. I Palaeontology.] 34 266 PAL.EONTOLOGY OF NEW-YOKE. this central axis is still preserved, extending beyond the other parts of the fossil. It expands gradually, from what appears to be the base, upwards for some distance, but rarely exceeds a single line in width. The scrratures are usuall}'- acute, but sometimes obtuse. The aspect of this fossil is very variable, depending in some degree upon the nature of the mass in which it is imbedded ; and it is not easy to determine what shall constitute specific characters in bodies so obscure as these, and of which we have but fragments. In the more calcareous portions of the rock they preserve a considerable thickness, but in the thinly laminated shales they form a mere carbonaceous film upon the surface. I have given figures of this species from various localities, and in slates of slightly different cliaracter, in order to present a faithful illustration of its usual form. Fig. 1 a. A fragment of arenaceous slate, from the Hudson-river group at Turin, preserving the bases of several specimens. Fig. 1 J. A portion of the same magnified. Fig. 1 c. A magnified fragment of the same species on the opposite side of this specimen, showing obtuse serratures. Fig. 1 d. A specimen of the same species, from the black slate of Oxtungo creek, south of Fort-Plain. Fig. 1 c. A magnified portion of the same. Fig. 1 / A fragment of the same species, from the olive slates of the Hudson-river group, at Loraine. Fig. 1 g. The same magnified, showing the obtuse termination of the teeth. Fig. 1 A. A specimen from the olive slate in Lewis county. Fig. 1 i. A magnified portion of the same. Fig. 1 k. A narrow and somewhat more finely serrated specimen, from the Utica slate. Fig. 1 l. The same magnified. Fig. 1 »». A small specimen, showing the axis extending beyond the serrate portion in both directions. Fig. 1 n. The same magnified. Fig. 1 0. A fragment of the same, from the black slates of the Hudson-river group near Albany. Fig. 1 p. A magnified portion of the same, showing the acute teeth near the base, and the broader obtuse ones above. All these specimens clearly belong to the same species, and the slight variations are due to accidental causes, or to diflerences observable in different parts of the same specimen, as is shown in some degree in the magnified portion 1 p. Fig. 1 r. This specimen resembles Gr. foliaceus of Murchison, and differs shghtly from tho preceding in the short mucrnnatc points of the tectli, shown in the magnified portion 1 s. In other respects it is similar. Position and locality. This species occurs in the Utica slate, and in the olive slates of tlie Hudson-river group, often very al)imdantly, and is widely distributed. It is found in great numbers in tlie black sla((! near tlie city of Hudson ; nt Stnyvosant, Columbia county ; near Albany, Ballslon and Baker's falls, in a similar slat(\; in the Utica slate near Fort-Plain, and at Herkimer, as well as other places in the Mohawk valley ; in the olive or greenish slates of tlie Hudson-river group at Loraine, Jefferson county, and at Turin in Lewis county, as well as several other localities in that part of the State. MTICA SLATE AND UUUSON-RIVEU OIIOUP. 267 3-22. 3. GRAPTOLITHUS SECALINUS. ■ Vl. LXXII. Figs. 2 o, *, c. Fucoidcs secalitius. Eaton. — simplex. Emmons, Tac. System, pag. 27, pi. 5, fig. I. — — Id. Agr. Report, pag. 71, pi. 17, fig. 1. Stipe linear, elongaleil, narrowing towards the base; width variahh;, from less than one line to one line and a half or two lines; axis usually obliterated, when preserved it is capillary like the preceding; margins serrated, teeth more or less acute. This species is very closely allied to the preceding, if not identical with it, tiie difference being due to pressure and the extreme lamination of the parts. When we examine a species of this genus imbedded in calcareous matter, and trace the same in its changes presented in the slates of different character, we shall be ready to admit that the variable expansion or width is an unimportant character. I am therefore scarcely willing to admit this one as a distinct species. The slates of the Hoosick quarries have been more metamorpho.sed than in any other locality where we find these fossils ; they are more perfectly laminated, and the surfaces extremely smooth and glossy. If we can imagine them to have remained in a somewhat plastic state, and with these imbedded fossils to have been acted upon in such a manner that the surface has been extended or spread out, as is always true in altered .^ilaty rocks, we can readily account for the greater expansion of the fronds of these graptolites without supposing them distinct species. In order to show that such a change may take place, I have introduced figures of specimens in the slate from Hudson and from Baker's falls, where the rocks are j)artially altered and more regularly laminated than in the Mohawk valley, in order to show the gradual change which supervenes in the G. pristis under such circumstances. In these specimens, particularly in fig. 2 b from Baker's falls, the substance of the fossil has almost totally disappeared, and is scarcely recognized, except by the difference of color in the surface of the slate. The same is always true in a greater degree of those from the Hoosick quarries, which are often so obscure that a particular direction of the light is necessary in order to distinguish the outlines of the fossil. To such causes, therefore, we may sometimes look for the foundation of species, particularly among forms like the Graptolites. Fig. 2 a. A portion of the surface of a lamina of the Hoosick slate, with specimens of this fossil presenting some variations in character. The broader one crossing the figure has the form and appearance of Prionotus folium of Hisinoer ; but it is evidently only a more extenuated form of the same species as the more elongated and narrower ones. Fig. 2 b, b. Fragments of the slate from Baker's falls, with forms intermediate between the more expanded varieties of G. pristis and those from Hoosick. Fig. 2 c. A specimen from Hudson, where the slates are partially metamorphic, but much less thinly laminated, and the fossils less expanded, than those at Bakei's fails or at Hoosick. 34* 268 PALEONTOLOGY OF NEW-YOKK. Still further east in the town of Chatham, where the slates are more altered, the Grapto- lites present a greater approximation to those of Hoosick. After examining great numbers of specimens from numerous localities, I am disposed to believe that the G. pristis, G. foliaceus and G. folium, as well as the one here indicated, may all prove identical, the differences being due to the greater or less degree of lamination in the shale, and the preservation of different parts of the fiond. Position and locality. This variety, in its extreme character, is known only in the roofing slate of Hoosick, in Rensselaer county, which overlies the partially metamorphic Trenton limestone. Approximating forms occur at Baker's falls, on the Hudson ; at the city of Hudson, and at Chatham in Rensselaer county. 323. 4. GRAPTOLITHUS MUCRONATUS (n. 57;.). Pl. LXXIII. Figs. 1 a, A, c,d. Linear, compressed to a thin film ; axis capillary, serrated on both sides ; teeth with mucronate tips. The serratures are slightly more distant than in G. pristis, and always mucronate. This character has been oliserved in several small fragments, which are very closely pressed in the thinly laminated slates. It is scarcely possible to conceive that the G. pristis assumes this character in some of its parts, and it cannot be due to pressure, since both forms occur together in the slates. Fig. 1 a. Two fragments of this species. Fig. I b. A portion of one enlarged. Fig. 1 c, d. Fragments of the same species, one of them much contracted, and both preserving extremely mucronate teeth. Position and locality. This species has been seen only in tlic partially altered and folded slates of the Hudson-river group near Albany. • 324. 5. GRAPTOLITHUS BICORNIS (m. 5;).). Pl. LXXIII. Figs. 2 a - s. Stipe linear, elongated, compressed, narrow, gradually widening from the base upwards; width one line or less ; serrated on both sides; serratures slightly oblique ; teeth about half the width of tlie stipe, obtuse at the extremities; axis capillary ; base or radix bifurcate. This species is clearly distinct from either of tlie preceding, and easily identified by the UTICA SLATE AND HUDSON-RIVER GROUP. 269 obtuse teeth, which are separated from eacli other \>y a narrow slit, and each one about half as wide as the entire width of the fossil ; the slit or serratiire extends al)out half way to the axis. The specimens all become gradually narrower towards the base, which presents two diverging forks ; these are sometimes thickened or expanded, and in other cases very slender, the scrrse often continuing beyond the divergence. But for the direction of the serrae, which are regarded as ascending, v/e might consider this bifurcation as the summit or termination of the fossil. When imbedded in calcareous matter, this species has a thickness of about half its width, witii a prominent round midrib on one side, and ihe other is often flat or depressed. The substance of the fossil, in such cases, appears to be calcareous or semicalcareous, with a corticiferous covering, wliich is probably true of all the graptolites. The specimens preserving their original form have the outer margins of the teeth concave, witli the upper and lower angles mucronate ; but this character is scarcely ever preserved when the fossil is imbedded in slate. Fig. 2 a. A small specimen of the natural size, showing the bifurcation below. Fig. 2 i. A portion of the same magnified, showing the form of the teeth. Fig. 2 c. A larger specimen, having the same character with a stronger bifurcation, which is thickened at the point of separation. . Fig. 2 d. A portion magnified. Fig. 2 e. A specimen having similar obtuse teeth, with the base removed and the midrib projecting above. Fig. 2/ A fragment of slate, with several specimens preserving the peculiar radical termination, associated with G. ramosus. Fig. 2 g, h. Magnified portions of these, showing a partly uniform character in the teeth. Fig. 2 i. A fragment of this species in the slate, preserving its original form in a good degree. Fig. 2 k. The same enlarged. Fig. 2 /. A fragment in limestone. 2 V. A more compressed form in the same. Fig. 2 OT, m'. Enlarged portions of the same. Fig. 2 m". A magnified view of the edge of a specimen in limestone showing an appearance analoi^ous to G. scalaris. Fig. 2 n. Transverse sections of the same magnified. Fig. 2 0. A slender specimen, with the sides parallel. Fig. 2 p. A similar specimen, preserving the capillary axis beyond the remaining portion of the stipe. Fig. 2 r, s. Magnified portions of these, showing their identity with the preceding. Position and locality. This species is among the most common in the slates near Albany, and at Ballston, Saratoga county. It is more rarely seen in the slates in Columbia county, and its occurrence in the Mohawk valley is doubtful. It occurs likewise at Cincinnati and other western localities, and appears to be the most common species in that part of the country, {State Collection.) 270 PALEONTOLOGY OF NEW-YOEK. 325. 6. GRAPTOLITHUS RAMOSUS (m. s;j.). Pl. LXXIII. Figs. 3 a- A. Stipe linear, narrow, scarcely one line in breadth, compressed ; serrated on both sides, except the branches ; teeth obtuse, distant, somewhat narrowed towards the base, more than half the width of the stipe ; stipes bifurcating or ramose ; branches slender, linear, serrated only on the outer margin. This species may be distinguished from the last by a careful examination of the serratures, which are proportionally deeper and more distant, as well as slightly more oblique and' narrowed towards the base. The radical termination has not been seen, and the species usually occurs in fragments of the simple undivided stem, or with a single bifurcation towards the extremity. Other specimens show a wide bifurcation with divergent branches, and others again are several times branched. When preserved in a tolerable degree of perfection, this is a beautiful and interesting species, presenting a character before unknown in this genus of fossils. The separate branches which are serrated on one side only, can be readily distinguished from the G. Sagittarius and G. tenuis, as well as from the preceding species, by the form and distance of the teeth, which are quite different in these species. Fig. 3 (I, a'. Small specimens near the radical termination, having a simple bifurcation above. This is the more common form. Fig. 3 4. A specimen with a more diverging and elongated bifurcation, with a smaller specimen lying obliquely across the right ramus. Figs. 3 i' &. 3 i". The same species. This and the preceding species are here grouped together on the same fragment of slate. Fig. 3 c, d. Enlarged portions of the two preceding specimens. Fig. 3 e. A specimen with elongated rami, which are serrated on one side only. Fig. 3/ A specimen branched below, and bifurcating above. The branches and bifurcate stipe above are serrated on one side only, while the stipe below and between the branches and bifurcation is serrated on both sides. This unique specimen proves that the inhabitant had the power of throwing out lateral shoots without dividing its axis; and also that the axis, when divided, does not afterwards become a perfect stipe in each of its two parts, tlie serrae continuing on one side only. Fig. 3 g, h. Enlarged portions, showing the character of the teeth at the points of divergence, below and upon the branches. Position and locality. This species ha.s only been obtained from the black glazed slates on the Norman's kill, near Albany, though it will probably be found in the localities of other species in Columbia county, and perhaps at Ballston, Saratoga county. {Slate Collection.) UTICA SLATE AND HUDSON-RtVEa GROUP. 271 326. 7. GRAPTOLITHUS SCALARIS. Pl. LXXIII. Figs. ia-g. Graptolithus scalaria. Li.n.vf.. Prionotus scahiris. IIisinijkr, Leth. Succica, Supplement, 1S37, pag. 115, pi. 35, fij;. 4 a J. Linear, straiglit, rigid, compressed, with a capillary central axis ; margins smooth ; spaces on each side of the axis marked by transverse slits or dissepiments, which do not reach the margin ; stipe narrowing towards the base, and terminating in a thickened expansion. This appears to be identical with the figure and description of Hisingeb.. I have other specimens which show no central axis, and have but a single range of transverse dissepi- ments ; these I have arranged with the former, believing that this difference is due to accidental causes, or to one side of the specimen only being shown. This species is more rigid than either of the preceding, except G. bicornis, and is readily distinguished by the absence of serratures on either margin. Fig. 4 a. A specimen showing the radical termination. Fig. 4 J. A portion of the same magnified. Fig. 4 c. A more slender and tapering specimen, with a single range of dissepiments. Fig. 4 d. A portion of the same magnified. Fig. 4 e, / A small fragment, with oblique dissepiments and smooth margins. This resembles the G. Sagittarius, with both margins uninterrupted. Fig. 4 ^. A specimen with, apparently, a single range of dissepiments, and a central capillary aiis projecting beyond the stipe. The forms given are quite variable, po.ssessing a single character in common, that of continuous smooth margins. The specimens are all exceedingly compressed, and it appears as if the apparently continuous margin may be fallacious, or due to the expansion of the thin covering of the stipe beyond the edges of the serra;. This conclusion appears more reasonable when we compare the nearly direct and oblique dissepiments, corresponding to the G. bicornis and G. Sagittarius. The same character has been observed by Capt. Poktlock {id cit., pag. 321, pi. 20, figs. 2, 3 and 4) . I cannot doubt but this one ( represented in fig. 4 a, 6 ) is the form to which Hisinger applies the name of Prionoius scalaris. Position and locality. This species, fig. 4 c, occurs in the Utica slate, on West-Canada creek. The other specimens figured were all obtained from the Norman's kill, near Albany. {State ColUctiun.) 272 PAL.EONT0LOGY OF NEW-YOEK. 327. 8. GRAPTOLITHUS SAGITTARIUS. Pl. LXXIV. Figs. 1 a, b. Prionotus Sagittarius. Hisinger, Leth. Suecica, Supplement, 1S37, pag. 114, pl. 35, fig. fi. Graptolithus Sagittarius. Poktlock, Geol. Rep. Londonderry, IS 13, pag. 3'20, pl. 19, figs. Sab. Stipe linear, straight or flexuous, extremely elongated, about one line in width, com- pressed ; one side smooth and the other serrated ; teeth oblique, acute, distant about half the width of the stipe. This species is readily distinguished from the preceding, by the regular strong serratures on one side of the axis only. Specimens of eight or nine inches in length are of frequent occurrence, and these are only fragments of much longer ones. It shows no apparent increase or diminution of width in either direction, and neither the lower or upper termina- tion has been observed. There is, apparently, a capillary axis near the smooth margin, and the surrounding substance of the stipe is sometimes of considerable thickness. The character is very uniform, showing, in a large number of specimens examined, no important deviation from those figured. This species is distinguished from the G. cUntoni of New-York by its shorter and stronger teeth, and by the same characters from G. murchisoni and G. sedgwickii of Europe. Fig. 1 a. A fragment of the slate, showing three nearly parallel stipes of this species. Fig. 1 b. A magnified portion, showing the upper margin of the teeth to be nearly rectangular to the direction of the stipe, while the lower side is oblique. Position and locality. This species occurs in the glazed and folded black slates on the Norman's kill, near Albany ; in the town of Stuyvesant, and near Hudson, Columbia county. 328. 9. GRAPTOLITHUS TENUIS. Pl. LXXIV. Figs. 2 a - d. Graptolithus tenuis. Portlock, Geol. Rep. Londonderry, pag. 319, pl. 19, fig. lab. Stipe very slender, filiform, straight or flexuous, with one side obscurely and distantly serrated, the other side smooth. This species is readily distinguished from the preceding by the appressed, obscure, and more distant serratures. The width in all the specimens examined is less than half that of G. Sagittarius, and it often appears as if both sides were destitute of serratures. Fig. 2 a. Slender elongated stipes of tliis species, associated witli G. Sagittarius. Fig. 2 b. A portion of one of these magnified. Fig. 2 c. A small filiform stipe, gradually tapering and bent abruptly backwards. Fig. 2 d. A portion of the same magnified, showing the serratures of the same character as the preceding. Positio7i and locality. This species has been seen only in the black glazed slates of the Norman's kill, near Albany. I'TICA SLATE AND HUDSON-RIVER GROUP. 273 329. 10. CRAPTOLITIIUS SEXTANS (n. .'fp.). Pi.. LX.XIV. Figs. 3 a - e. Slender, bifuicating from the base; branches linear, straii^ht, serrated upon the outside; serratures oblique ; teeth sharp, and extended into a slender iiuicronate point. In perfect specimens, two small seta; extend from the base, one on each side. This small species appears to i)e (piite distinct from either of the others. In a considerable number of specimens examined, it, bifurcates at the base, from l)eneatli which two slender spines or bristles proceed. The bifurcations are straight, ami regularly diverging at an angle of sixty degrees. The angular teeth on the outer margin always preserve a mucronate point when perfect, and this character is sufficient for identifying small fragments. Fig. 3 a. A fragrncnt of slate on whicii are two specimpos of this species, with straight diverging branches. Fig. 3 i. A portion of one of these magnified, showing the mucronate teeth. Fig. 3 c. Specimen with larger branches. Fig. 3 d, d. Two specimens, showmg the appendages at the base. Fig. 3 e. One of the last magnified. Position and locality. This species is known to me only in the black slates of the Norman's kill, near Albany. {State Colltciwn.) 3.30. 11. GRAPTOLITHUS FURCATUS (/(..?;).). Pl. LXXIV. Figs. -1 a -/. Stipes slender, bifurcating near the base; branches diverging, curved in the centre, and converging towards the extremities ; stipe below the bifurcation serrated on both sides, branches serrated on the outside ; teeth nearly as wide as the branches, rectangular, obtuse ; inner side of the branches more obliqely serrated. This small and peculiar species is readily distinguished from cither of the preceding, by its curving bifurcations, and shape of the serratures. In a laige number of specimens examined, it preserves the form and character given in tiie figures, and a single branch can be distinguished by a careful comparison. It differs in its mode of l)ifurcating from G. ratnosus, and is always smaller and narrower. Fig. 4 a. An individual on the same stone with 3 d, showing the difference in form. Fig. 4 i. A magnified portion of the same. Fig. 4 c. A small specimen, with the branches more converging than usual. Fig. 4 d. A portion of the last magnified, showing no serratures on the inside of the branches. Fig. 4 e. Another specimen, similar in form to 4 c. Fig. 4/ A part of the same magnified, showing serratures on the inside of the branches. Position and locality. In the glazed slates of the Normairs kill, near Albany, [ Palaeontology | 35 .t ••' 274 PALAEONTOLOGY OF NEW-YOKK. 331. 12. GRAPTOLITHUS SERRATULUS («.«/).). Pl. LXXIV. Figs. 5 a, b. Stipe Straight, slender, almost filiform, widely diverging from an acute point ( the basel); upper or inner edge serrated; teeth triangular, distant nearly the width of the stipe; serratures nearly as deep as half the width of the stipe. This species closely resembles the G. Sagittarius, but differs in the greater obliquity of the serratures and the distance of the points of the teeth, which are, in this specimen, equal to that species where the stipe is more than twice as wide. This character may prove sufficiently distinctive to identify small fragments of the two species. Fig. 5 a. A specimen of the natural size, diverging from a slender smooth spine or mucronate radicle below. Fig. 5 b. A portion magnified, showing the form and opposite direction of the serratures at the base. Position and locality. This is found, associated with several of the preceding species, in the black slates at Norman's kill, near Albany. 332. 13. GRAPTOLITHUS GRACILIS (71. s;?.). Pl. LXXIV. Figs. G a, b, c, d. Stipe very slender, branching from one or both sides ; branches slender, gradually enlarging, sometimes dividing, distinctly serrate ; serratures oblique ; teeth distant, ap- pressed, or scarcely distinguishable above the outline of the branches. This is much the most slender and graceful species among the Graptolites. In the examination of a large number of specimens, I have not been able to learn that the principle stipe is serrated, though the branches are distinctly so on one side. Figs. G a, b. Two specimens, natural size, showing the principal stipe and branches, one of the latter being subdivided. Fig. 6 c A specimen in which the principal stipe is obscure; several branches are subdivided. Fig. 6 (2. A fragment magnified, showing the serratures of the branches. Position and locality. This species is only known to me in the black slates on the Norman's kill, near Albany. 333. 14. GRAPTOLITHUS? L^VIS (n. 5/).). Pl. LXXIV. Fig. 7. Stipe slender, linear, flexuous, smooth on both margins ; not branched. This fossil presents the same appearance as the Graptolites, and occurs in the same position. I have several specimens, all presenting a uniform character ; and from its being of conunon occurrence, I have figured it in this connection. Position and locality. In the Utica slate, at Turin, in Lewis county. hUDSON-RIVER GROUP. 275 CORALS OF THE HUDSON-RIVER GROUP. Plate LXXV. We have few additional species of the solid corals, beyond those common to the Trenton limestone. The comparatively small amount of calcareous matter furnished during the deposition of the materials of this group, show at once why so few Corals flourished in that period. And we again find, as before remarked, that as the formation becomes more calcareous in its western extension, the Corals increase in number of individuals and species, in some places constituting a large proportion of the rock. In the shaly and arenaceous strata of this group in our own State, we are, for the most part, forced to depend upon the exterior moulds of tliese forms, the calcareous matter of the coral having been dissolved and removed. In more favorable situations the specimens are well preserved, but they never acquire the perfection and beauty which is seen in those from the same position in Ohio, Indiana and Kentucky. Genus FAVISTELLA. [Latin, favus, honeycomb, and slella, a star.] Character. Coral massive, hemispheric or globose, composed of polygonal tubes or cells, which increase by interstitial lubes, or by lateral developments of tul)cs upon tlie margins of the mass; cells divided transversely by closely arranged diaphragms, and lono-itudinally by radiating dissepiments; extremities of the tubes starform ; rays (dissepi- ments) about twelve, more or less, meeting in the centre. The rays generally reach one half or two thirds of the distance from the margin to the centre. .334. 1. FAVISTELLA STELL ATA («..9p.). Pl. LXXV. Fiijs. 1 a, b, c. Coral hemispheric or spheroidal ; cells polygonal, with diameters of one eighth or one tenth of an inch ; walls of the cells not separable as in Favosites, but apparently composed of a single partition or lamina. The tubes are usually six-sided, and two rays or dissepiments proceed from each side; in other specimens of interstitial tubes there are a less number of sides, and consequently a less number of dissepiments. The diaphragms are usually nearly direct, or bending slightly downward at the margins. This species is one of the most beautiful corals among the older rocks. The ends of the 35* 276 PALAEONTOLOGY OF NEW-YORK. tubes present a beautiful strllate appearance, and the mass is often as open and free from the infiltration of mineral matter as in the recent corals. In weathered specimens, the sides of the tubes show the remains of the vertical and transverse partitions of the adjoining cells. Fig-. 1 a. A fragment of this coral, showing a vertical section, with an oblique section of the extremities of the tubes. Fig. 1 b. A transverse section of the cells, showing the starlike extremities. Fig. 1 c. An enlarged view of the extremities of several cells. Position and locality. This species is scarcely known in New^York, a few obscure speci- mens being all that I liave observed in the shaly parts of the Hudson-river group. In the western extension of the same formation it is abundant, and developed in large spheroidal and hemispheric masses. At Madison, Indiana, this species forms two distinct layers near the top of the shales of this group, occurring in masses of from one to three feet in diameter. (State Collection.) 101. 2. CH^TETES LYCOPERDON. Pl. LXXV. Figs. 2 a, b, c, d, e,f. Reference pag. 64, pi. 23 and 24 of this report. This coral acquires its full development in the shaly part of the Trenton limestone, rarely appearing in hemispheric forms in the succeeding shales. In the more calcareous part of the Hudson-river group it occurs in ramose forms, similar to those already described, and assumes some other features in its mode of growth not observed in the limestone. Notwithstanding the fact that it is rarely or never found in the hemispheric form, the animal appears often to have commenced its growth in this way, and to have discontinued it, probably from unfavorable circumstances, while the slender branching forms are numerous in the same situation. Fig. 2 a, h. The bases of two hemispherical forms, where the tubes have a barely perceptible extension. Fig. 2 c. A fragment of a ramose form, one of the largest occurring in this group. Fig. % d. K subhcniispheric form, which commenced its growth upon the column of a crinoid. Fig. 2 c. A fragment of stone, with several ramose forms associated with a crinoidal column, a small Murchisonia and Orthis testudinaria. Fig. 2/. Magnified section of a ramose form, showing the columns to be nearly parallel to the axis of the specimen. Position and locality. This species occurs throughout the Hudson-river group, particularly in the calcareous strata ; and though assuming a somewhat different aspect from the same species in the Trenton limestone, is nevertheless identical. The principal localities are Turin, Lewis county ; Loraine, Jefferson county; Pulaski, Oswego county; and it is also found in numerous other places. (State Co/lection.) HODSON-RIVER GEOUPi 277 Genus D I S C 0 P II Y L L U M. [Greek, (Sio'xos, a disc, and (jjuXXov, a leaf.] Character. Discoidal, flattened, rays or disscpiniciits numerous, proceeding from the centre; body of the fossil apparently semicalcareous or corticiferous ; margin well defined. From the semi-metamorphic condition of the rock, it is impossible to determine whether this body was calcareous ; but it appears to have been otherwise. 335. 1. DISCOPHYLLUM PELTATUM (n. s;;.)- Pl. LXXV. Fig. 3. Body consisting of a somewhat circular flattened expansion, composed mainly of radiating fibres, which enlarge as they recede from the centre, and terminate in a thickened border. This fossil appears to have consisted, originally, of a semi-hard circular or oval body, with firmer rays, reaching nearly or quite to the margin. The body becomes thicker and apparently harder towards the margin, and the rays are nearly concealed in its substance. This disc may have been attached by a smaller stipe, proceeding from the lower side, some obscure evidence of such an appendage existing. Two specimens of this peculiar fossil have been found : one in 1822, and the other a few years since, showing that it is an exceedingly rare form. It is (juite unlike any other fossil known in our older strata. Position and locality. This species occurs in the partially metamorphic arenaceous shales of the Hudson-river group, near the Nail Factory, below Troy, where the only known specimens have been found. , (Cabinet of Tray Lyceum; Cabinet of Prof. Cook.) 336. 1. (Undetermined.) Pl. LXXV. Fig. 1. The specimen figured is an impression of the outer surface of some incrusting coral, frequently foiuid attached to the shell of tlie Orthoceras coralliferum. It appears to be composed of large elevated points or stars, with an intermediate granulated or papillose surface. It is usually obscure, or very imperfectly preserved, the more elevated points only being visible. The figure is of the natural size, from a specimen adhering to an Orthoceras. This coral is also represented in an imperfect specimen attached to another shell of tlie same species (Plate Ixxxvi, fig. 1 ) . It is sometimes found under other circumstances, and attached to other shells, but always so obscurely preserved that its characters cannot be well determined. Position and locality. Tiiis coral is known in many localities of the Hudson-river group, widely separated from each other. It has been found at Turin, Pulaski, Loraine ; near Rome, in Oneida county ; in the altered shales near Waterford, and in the same situation in Ohio, near Cincinnati, C^'"'' Collection.) 278 paljEontology op newyork. CRINOIDEA OF THE HUDSON-RIVER GROUP. Plates LXXVI., LXXVII. & LXXVIII. Scarcely more than three well marked species are known in this group, and one of these may be regarded as having existed during the period of the deposition of the Trenton limestone. The fragments of these species, and the columns of the same, appear under so many different forms and aspects as to indicate a greater number of species than really exist, and on this account have been more fully illustrated. The characteristic species of the Trenton limestone ceased to exist with that formation, and the peculiar forms so well preserved in that rock do not appear beyond its termination. At this period the nature of the sediment in its eastern part was not well adapted to the growth or preservation of this class of animals ; and, as might be expected, we find in the western extension of the same, where the mass becomes more calcareous, an increase of the number, and a better pre- servation of their remains. In addition to the unequivocal forms of Crinoidea, the western localities of this group have afforded several species of the asteroid form, which have a very close resemblance to the true Asterias. A single fragment of this character has been found in the shales of this group on the south side of the Mohawk valley, but it is too obscure to be described. All the forms here described, as well as those from the Trenton limestone, terminate their existence with this formation, and the next rock in which such remains occur presents us with a new assemblage. Genus HETEROCRINUS. [Greek, s-rspoff, irregular, and xpivos, a lily] Character. Column more or less pentagonal ; pelvis composed of five plates, which are somewhat irregular ; costal plates in a single or partially double series, pentagonal, heptagonal or quadrangular ; scapular plates regular ; arms variable in character ; fingers composed of a double or single series of quadrangular joints, which are not tentaculated. The two species which I have placed under this genus, have a similar pentagonal column, with the pelvic plates similar in each. The succeeding plates are somewhat irregular, but are few in number, and the entire structure very simple, interposed plates being entirely absent. Allhough I have liut two species, and of these only imperfect specimens, it is evident that they may with propriety constitute a distinct genus, on the basis of Miller's arrangement. The third species, which is provisionally placed under this genus, cannot be satisfactorily determined at present. HUDSON-RIVER GROUP. 279 337. 1. HETEROCRINUS HETERODACTYLUS. Pi.. LXXVI. Figs. 1 a - o. Body short, rounded, subcylindrical, tapering above and below ; pelvis composed of five small pentagonal plates, wliich are succeeded by the same numljer of larger costal plates, and these again by five scai)ulars ; arms irregularly subdivided ; column pentagonal, composed of thick joints, which are nodulose at the angles ; joints alternating in size as they approach the pelvis. This is a peculiar species, remarkable for the small size of the body when compared with the column. The irregularity of the arrangement of the plates in the arms and fingers is likewise a striking characteristic of the species, which is constant in two specimens from difierent localities. In one of the arms ( fig. Id), the scapular plate ( h ) supports a regular series of six or more plates (7 1 ) of similar form without division. The arms at the right and left of this one are again unlike each other. Tlic one on the left has three regular and gradually diminishing joints (^2) above the scapular, and of the same form ; the last one supports the cuneiform joint ( |^ ), which again supports a double row of joints ( or a pair of fingers ) . The arm on the right of the first mentioned, consists of a pair of quadrangular joints ( 5. 3 ) , each of which supports a cuneiform joint (Li). In the remaining two arms, no plates have been traced beyond tlie scapulars, and consccpiently the entire form of tlie species cannot be determined. Sufficient is visible, however, to show the irregular character of the arms, from which its name is given. Figs. 1 a, b. Two specimens of the natural size. Fig. 1 c. The body of the same enlarged. 1 c'. Transverse section of iho column, enlargc-d. Fig. 1 d. An enlarged figure, representing the structure of this species. Figs. 1 e,f. Fragments of slate with pentagonal columns of this species, showing the body at/'. The fragments of round columns in the same specimens are of another species (see Plate Ixxvii). Fig. 1 g. A fragment of one of these columns enlarged, showing the nodulose angles. Fig. 1 h. A fragment of a column, with a section of the same. Fig. 1 i. A fragment of slate, showing numerous impressions of the discs or plates of the column. Fig. 1 k, I, m, TO, 0. The same magnified, showing the pentapttalous expansion around the canal, and the deeply impressed strioe, which are different in each one. Where tlic column is crystalized these markings are not visible. Position and locality. Fragments of the columns of this species are found in the shales of the Hudson-river group, in nearly all localities. Of the two individuals figured, one is from near Boonville in Lewis county, and the otiier from Loraine, .JeilVrson count}'; it is also found near Rome, Oneida county. I have the same species from the shaly strata near Cincinnati, Ohio. («a/e Collection.) 280 PAL.EONT0LOGY OF NEW-YORK. 338. 2. HETEROCRINUS SIMPLEX. Pl. LXXVI. Figs. 2 a, b, c, d. Body slender, very gradually expanding above the base, and composed of five regular divisions above the pelvic plates; pelvic plates five, four of them irregularly pentagonal, and one wiih the lateral and upper margins equal ; costal plates in two of the divisions single, hexagonal, and supported on the straight upper edges of the pelvic plates, those of the three other divisions double, the lower one pentagonal with the lateral margins short, the second one quadrangular ; scapular plates quadrangular, with the upper sides concave and supporting a pentagonal arm-joint ; arm-joint supporting on its oblique upper edges a double series of obliquely quadrangular or rhomboidal plates, which gradually diminish in size ; column subpentagonal, composed ( near the pelvis) of alternating thicker and thinner plates. This species is readily identified by its structure, which is peculiar in the form of four of its pelvic plates, and the double or subdivided costal plates in three of the divisions ; the body and arms, when closed together, present a slender subcylindrical form, scarcely attracting attention, from their resemblance to a collection of small individual columns. The small fragment of a column attached, which is crushed, can scarcely be characterized, but it is clearly pentagonal. I am indebted to Mr. J. G. Anthony, of Cincinnati, for the specimen here figured. Fig. 2 a. The specimen, natural size. Fig. 2 4. A few joints of the columns enlarged. Fig. 2 c. Section of the same, which is flattened from pressure. Fig. 2 d. An enlarged figure, showing the structure of the body and arms of this species. Position and locality. In the soft shaly portions of the Blue limestone of Ohio at Cin- cinnati, equivalent in position to the Hudson-river group of New-York. 339. 3. HETEROCRINUS? GRACILIS. Pl. LXXVI. Figs. 3 a, b. This is a small slender species, with the body but little expanded, supporting long and slender fingers, which are not fimbriated ; column pentagonal, proportionally large ; the plates distant, not nodulose on the angles ; radicles numerous, jointed, diverging. This is a very delicate species, approaching in form and general appearance to the first species ; but the plates of the body arc so far destroyed that their arrangement cannot be determined. The angles of the column are not nodulose, as in that species, and this is almost the only olnious mark of distinction. FijT. 3 a. The .specimen of the natural size. 3 h. The same magnified. Position and locality. This species occurs in the soft olive shale at Snakehill, Saratoga ijjjjg (State Collection.) HUDSOM-RrV'ER GROUP. 28 1 Genus G L Y P T 0 C R I N U S. [Greek, yXi/irros, sculptured, and xpivos, a lily; in allusion to the deeply carved or sculptured plates of the body.] Character. Column rouiul ; pelvis composed of five plates ; costals in two series, with a single regular intercostal j)latc ; scapulars five, with two interscapular plates ; scapulars supporting a pair of arm-plates, which are succeeded by the hands and fingers. 340. 1. GLYPTOCRINUS DECADACTYLUS. Pl, LXXVII. Figs. 1 a -/; and Pl. LXXVIII. Figs. I a - u. Body cupshaped, with ten arms, which support twenty tentaculated fingers ; plates all marked by strong elevated radiating ridges ; pelvic plates five, pentagonal, supporting upon their upper oblique edges five heptagonal costal jjlates, which are succeeded by five hexagonal second costals in a direct line ; scapular plates heptagonal, resting directly upon the straight upper side of the second costals, and supporting on their two upper obli([ue edges two hexagonal arm-joints, which in turn support a second arm-joint, and this one two hexagonal hand-joints, the latter sustaining the fingers ; fingers composed of a column of fimbriated joints, which are quadrangular below and cuneiform above ; column round or obtusely pentagonal, varying in its character at different distances from the body. In addition to the regular series of plates supporting the arms and fingers, there are numerous intermediate ones, of which a hexagonal intercostal plate, a first pair of hexa- gonal interscapular plates, and a second pair of heptagonal interscapular plates, the latter truncated above, are always regular and uniform. Between these last interscapular plates, there is usually an irregular interscapular joint, and several pectoral plates. The number and arrangement of the latter does not appear to be always uniform ; but I have not been able to find specimens where every part could be satisfactoril}- examined. Between each pair of arms there are three or more plates, and between each pair of fingers one or more plates at the base. The capital plates, and their arrangement, are shown in the enlarged figure of the crown, fig. 1 d, pi. 77. The mouth is depressed and obscure. The body of this species is readily recognized by the strong radiating ridges which mark the surface of all the plates below the tentaculated fingers. The surface is also marked by five more prominent ridges, which, proceeding from the first costal plates, bifurcate on the scapular plate, the divisions extending to the base of each pair of fingers. In these characters of the surface, and in "its general structure, it resembles some species of the Genus Actinocrinus, from which it differs in having five instead of three pelvic plates.* • Tlie first notice of this fossil was given by Mr. J. G. Anthoxy of Cincinnati, in Siluman's American Journal of Science, 1838, Vol. xxxv, p. 405. Mr. A. gives a very good figjure of this beautiful species, but proposes no name, [ Paleontology.] 36 282 paljEONtologt of new-yokk. There is some difficulty in making out the entire structure, since the plates usually adhere very closely, and some of the pectoral and intcrbrachial plates are very small. The important parts, however, and the plates proceeding to the arms, are readily and clearly determined. This fossil is usually found destitute of the column ; and I have not been able to decide satisfactorily whether all the fragments found with it are parts of the same, or belong to two species. The first, which evidently belong to this species, and form the upper part of the column, consist of joints, having a small base resting upon the broader disc of the next one below, giving more freedom of motion. Other portions have the upper sur- face of the disc excavated, and the column appears to be composed of a series of cups, alternating in size and placed one within the other, having the upper edges either smooth or fimbriated (figs. 1 a and 1 6, pi. 78). These columns have usually a distinct round alimentary canal, with the upper and lower siuface marked by fine rays, more deeply impressed near the edge. In other parts of the column, where the plates are more nearly equal in size, the upper and lower surfaces have a pentapetalous impression or elevation radiating from the alimentary canal. This character, in fine, becomes the prominent and characteristic one of the greater proportion of the fragments of columns which we find ; and they present all the variety of broad equal smooth joints with even surfaces, or of similar joints with a thin plate interposed, and of columns composed of moniliform joints with smaller ones between ; or of distant rounded joints, sometimes deviating slightly from a cylindrical form. All the important varieties are illustrated by figures. Plate LXXVII. Fig. 1 ffl. A fragment of stone with two small specimens, preserving the tentaculated fingers. Fig. I b. Figure of a larger specimen, showing the character of the plates and their arrangement more distinctly. The bases of the fingers, with about five or six joints, are preserved in this specimen. Fig. 1 c. The upper e.xtremity or crown of the last specimen, showing the capital plates. Fig. 1 d. The same enlarged. Fig. 1 e. A portion of the surface enlarged, showing the form and character of the plates, and the strong radiating ridges. Fig. 1 / An enlarged figure, showing the structure and arrangement of the plates as described. A small portion only of ihe plates of the fingers are represented, but there are no subdivisions beyond this point. Plate LXXVIII. Fig. 1 a. A figure of a specimen, preserving a small portion of the column and the entire length of the fingers. Fig. 1 b. Fragments of columns, composed of alternating larger and smaller discs with angular edges. suggesting that it may be an .flpiocrinite, which proves otherwise on examination. From his account, it would appear that the first specimen was found at Cincinnati, in 1837. This species is probably one of those named in Dr. Owen's Catalogue ; but I have never seen a description of the same, nor received a specimen with the name attached. IIUDSON-RIVEK GROUP. 283 Fig. 1 c. Section of the same. Fig. I d. Section and figure of a similar fragment of a column enclosed in a coral. Fig. 1 e. Fragment and section of a column where the discs are e.\cavated on their upper side, and have plain rounded edges with a penlapetalous impression on the e.xtremiiics. Fig. 1 /. Fragment of similar character, having the upper edges of the plates fimbriated. Fig. 1 g. Section of the same, enlarged. Fig. I h. A magnified portion of 1 f, showing the fimbriated edges of the discs. Fig. 1 i. Separate plates or discs of a similar column, showing the variable character of lire marginal crenulations, one specimen being marked by si.x prominent angles. Fig. 1 k. Two figures, showing the proportionate size of the larger and smaller discs in the columns, composed of plain alternating joints. Fig. 1 Z. A fragment of slate, with impressions of various discs of columns. Fig. 1 m. Several of the same enlarged, showing their analogy with the preceding and following forms. Fig. 1 n. Fragment of a column, with the edges of the discs rounded and slightly nodulose; iiitcr- mediate plates thin. Fig. 1 0. Edges of the discs rounded and subnodulose; intermediate ones thin, nodulose. Fig. 1 p. Edges of the dijcs rounded and smooth, the intermediate ones thin. Fig. 1 r. Edges of the discs flat and broad, the intermediate ones thin. Fig. 1 s. A fragment of slate with moniliform columns; the intermediate plates often being scarcely distinct, while in others they are half as thick as the larger ones. Fig. I t. Large fragments of columns in the compact slaty rocks of the Hudson-river group, with the discs thick, the intermediate ones being scarcely visible. Fig. 1 u. A similar fragment of a column, with a section of the end, showing its identity with the preceding figures. These figures illustrate nearly all the varieties of form usually seen in the columns of this species. There are some others presenting deviations greater than those figured, of which I have some doubt as to their specific identity, and therefore do not give them in this place. I have also entertained some doubt as to the propriety of uniting the figures from 1 n, pi. 78, onwards with the preceding, .since I have not been able to tiace a positive connection between the remote forms, though fig. 1 e, which is clearly identical with the preceding figures of columns, presents the pentapetalous impression on the extremity of the discs. Position and locality. This one is the most common species of this family in the western extension of the formation, occurring at Cincinnati (0.), Maysville (Kj'. ), and Madison (Indiana). In numerous localities in New-York, fragments of the columns are abundant, but I have never been able to find the body. Fragments of cohuuns, well preserved, are abundant in western localities. Those figured are from Cincinnati (Ohio), Maysville ( Kentucky) , Pulaski, Turin, Loraine, Boonville, and other places in New-York. (State Collection.) I am indebted to Mr. Joseph Clarke, to Mr. Anthony, and to Mr. Carly of Cincinnati, for beautiful specimens of this species. 36» 284 PAL.SWNTOLOGY OF NEW-YORK. 129. 1. TENTACULITES FLEXUOSA. Pl. LXXVIII. Figs. 3 a, b. Reference pag. 92, pl. 39, fig. C of this report. Tentaculites. Emmons, Geol. Report, 1842, pag. 404, fig. 6. Compare Cormilites serpulariiis, Schlotheim. Murchison, Sil. System, pag. 627, pl. 26, figs. 5 - S. This species is equally as abundant in the rocks of the Hudson-river group as in the Trenton limestone. In the latter it often attains a greater length, and is nearly straight or simply curved. The flexuous character, therefore, may not be constant or essential in distinguishing the species, though I have not seen perfectly straight specimens. In the shales and ferruginous shaly sandstones of the Hudson-river group, the moulds only of this species are found, and the fine longitudinal striae are rarely well preserved. It is distinct from either of the species described by Mr. Muhchison, from the Caradoc sandstone.* Fig. 2 a. Fragment of the stone with several specimens a, a, a, associated with corals, shells, etc. Fig. 2 J. A specimen enlarged, showing the longitudinal striae. Position and locality. In the middle and higher parts of the Hudson-river group at Turin, Boonville, Loraine, Pulaski, and other places in New-York ; at Cincinnati ( Ohio ), Maysville ( Kentucky ) , and Madison ( Indiana ) . NOTE TO THE CRINOIDEA. Since this volume will be published without the elementary portion, which is in pre- paration, and will form a part of the next volume, the following explanations are given of the signs used in designating the structural arrangement of these animals. Those only are given which are used in the plates of this volume. B. Base of attachment. E. Pelvis. F. Costal plate or joint. G. Intercostal plate or joint. H. Scapular plate. I. Interscapular plate. J. Irregular interscapular plate. K. Arms. L. Cuneiform joint. M. The hand. N. The fingers. Ql. Pectoral plates. R. Capital plates. Cuneiform arm-joint. First. Second. Jnint, as L, first costal ; L, second costal, etc- -, arm-joints. • In the description of this species, I had overlooked the analogy in its mode of growth to that of the Cornulitcs serpulariiis, so fully illustrated by Mr. Murchison. The structure, however, is quite different, being annulated by sharp equal ridges, and not composed of sections of different sizes, one proceeding from the other. The apparently septate character, shown in a single large individual in the Trenton limestone, may indicate a structure incompatible with the true Tentaculites. Its geological position is below that of the Cornulites serpulariiis ; and should further examination and comparison prove it to be generically allied to that one, it will form a distinct species. HUDSON-RIVER GROUP. 285 BRACHIOPODA OF THE UTICA SLATE AND HUDSON-RIVER GROUP. Plate LXXIX. Few species of this class are known in tlie Utica slate, and the individuals rarely found are specifically identical with those of the Trenton limestone. As the shales become less carbonaceous and lighter colored, with an admixture of arenaceous and calcareous matter, some of the species so abundant in the Trenton limestone again make their appearance in great force, and characterize the strata in almost all localities. Although, from the nature of the mass, they are in a different condition, they nevertheless preserve all the peculiarities of the same species in a lower position ; while the absence of the shell, and the abundance of moulds of the interior and exterior surface, have induced an opinion that (here are several distinct species. This remark is peculiarly applicable to the Leptama alternata, which is rarely found preserving its shell entire, while the impressions of the outer and inner surface are abundant. This species has already (pages 102, 103 and 104, PI. 31 and 31 a of this volume) been fully illustrated, and a few figures presenting its appearance and character in this group are given in the present connection. It should be borne in mind, however, that comparatively few of the Trenton limestone species of Braciiiopoda are found in the strata of this group, the larger portion ceasing their existence with that rock. The forms given on Plate Ixxix are nearly all that usually occur; the Lcptcena alternata, L. scricea and Orthis testudinaria being quite abundant, while the Atrypa and Lingula are rare. At the same time we find two other species of Orthis, wliich have not been observed in the limestone below. The same horizon, in the western extension of the formation, gives us not only the Trenton limestone species, but also several others not known within New-York. The few species occurring in this position in New- York, differing from those known in the Trenton limestone, are not therefore to be regarded as offering any important distinction between the two portions of the group ; for we shall doubtless yet find many more in the lower limestones than we now know. 133. 7. LINGULA QUADRAT A. Pl. LXXIX. Figs. 1 a,b. Reference pag. 90, pi. 30, fig. 4, of this volume. Lingula rectiliileris, Conrac, MS. Emmons, Geol. Report, 1312, pag. 39^, fig. 0. I am unable to perceive any essential difference between this shell and the /.. quadrata of the Trenton limestone. The figure given by Prof. Emmons has the sides straighter and the upper extremity more pointed than the original specimen. In two specimens examined there is a slight difference in the form, owing in part to compression ; but there is no more 286 PALEONTOLOGY OF NEW-YORK. deviation than is often observed in the same shell in the limestone. The surface is marked by concentric lamellose striae, and the centre by nearly equal longitudinal stria; ; the sides are more or less straight, the base rounded with the upper extremity often subcuneate, having the slopes nearly direct. The base is sometimes nearly straight, and the shell resembles L. lewisii. Figs. 1 a, b. Figures of two specimens, showing the difTerence ordinarily seen in the form of this fossil. Fig. 1 c. A portion of the surface magnified. Position and locality. In the soft argillaceous shales in the lower part of the group at Loraine, Turin, and other places. (State Collection.) 141. 4. LEPT^NA ALTERNATA. Pl. LXXIX, Figs 2a-/. Reference pag. 102, pl. 31 and 31 a, of this volume. Strophomena nasuta. Conrad, Jour. Acad. Nat. Sciences, Vol. viii, p. 100. — — Emmons, Geol. Report, 1842, pag. 403, fig. 3. Strophomena. Id. lb. pag. 403, fig. 2. This species occurs under a variety of conditions, and often presents a different aspect from the same in the Trenton limestone ; but a comparison of several hundred specimens has convinced me that it is identical. The casts of the interior are striato-punctate, as in all the Lept.5:na ; and the alternating character of the striae is not well preserved, or even at all visible. The circumstance of having one or two of the central lines larger than the others is often observed, and we have the same, already noticed, in tliose of the limestone. This character, therefore, which has been regarded as reliable for distinguishing it from L. alternata and L. deltoidea, is of no importance. It presents in these rocks, as in the limestone below, all the varieties from forms acutely nasute in front, to those of regularly curved outline, and entire absence of this character. The impression of the outer surface of the shell, so often preserved in these rocks, shows, in a very perfect manner, the beautiful fascicles of strife, separated by larger ones. This character, however, is not always evident ; neither does it exist equally in all specimens. In a few localities we find this species with the shell perfect, showing in all its variety the same character which the species every where exhibits, and which is even more strongly marked and better preserved than is usual in the limestone. The most interesting parts of tlie shell, however, are the moulds of the interior of the valves, which are never found in the Trenton limestone. These reveal important characters of the species, on which we may rely in distinguishing it from others. Fig. 2 a. Mould of tlie intcTior of the convex vah-e of this species, showing tl.e form of the visceral impression, the obHqiie teeth, etc. The nasute character is well preserved. Fig. 2 b. Figure of a similar specimen, where the nasute character is less conspicuous. Fig. 2 c. A smaller specimen of the same character, showing a slight contraction in front. The entire surface in such specimens, when well preserved, is striato-punctate. HUDSON-RIVER GROVPt 38T Fig. 2 d. A portion of the surface of one of these enlarged, showing the striato-punctate character. Fig. 2 e. A cast of a large symmetrical specimen, showing the same characters of the surface, form of visceral impression, etc. Fig. 2/ The impression made by the outside of the convex valve of this species, showing the fascicles of stria; in a perfect manner. Specimens like this and the preceding are often found in connection, giving the impressions made by the two sides of the valve. Fig. 2 g-. A small specimen, preserving the shell, and showing the strise in interrupted fascicles. Fig. 2 ^f. A portion of the surface enlarged. Figs. 2 A, i. Figures of specimens which still preserve a part of the shell, having the striiB in broad fascicles of small ones separated by larger ones. Fig. 2 k. Interior of the concave valve, showing the two small teeth on the hinge line, with three diverging callosities. Fig. 2 I. Mould of the interior of the flat valve, showing the two cavities made by the teeth, and the impressions of the radiating callosities. The general aspect of this species, a.s it occurs in tlie slialy and arenarooiis strata of this group, is more nearly like the same in tlie Blue liine.stonu of Ohio and other western localities, where there is a considerable admixture of argillaceous matter in the mass. In both the Hudson-river group of New-York, and the western extension of the same strata, where there are frequent alternations of slialy, arenaceous and calcareous matter, there is a greater variety in form and appearance of the fossils. This species, therefore, in the numerous localities within this State, presents much diversity of appearance, depending upon the character of the rock, or upon the partial preservation of the shell. Position and locality. The most prolific localities of this species in this group are Pula,>ilvi, and Washingtonville, in Oswego county ; near Rome, Oneida county ; near Boonville, Turin, and Martinsburgh, in Lewis county. It is cf|ually abundant in numerous localities on the north side of Lake Ontario. {State Collection.) 146. 9. LEPT.^NA SERICEA. Pl. LXXIX. Figs. 3 a, 6. Reference pag. IID, yil. .31 b, of this volume. This species is often quite abundant in the rocks of this group, extending almost to its highest limit. The shell is usually removed, and specimens are found mostly in the form of moulds or impressions of the shell. In some localities, when well preserved, the alternating stronger stria; are more distinct than in those of the Trenton limestone. Fig. 3 a. A mould of the interior of the shell. Fig. 3 b. An enlarged portion, showing the striato-punctate character of the surface. Position and locality. This species is found in all the localities with the preceding, and rarely in the Utica slate. {State Collection.) 288 Paleontology of new-york. 155. 2. ORTHIS TESTUDINARIA. Pl. LXXIX. Figs. 4 a, *, c, d, e. Reference pag. 117, pi. 32, of this volume. In the shales of this group, this species is rarely preserved with the shell entire ; casts of the interior, or impressions of the exterior of one or both valves, being the usual form in which it is found. In some situations, it is almost equally as abundant as in the Trenton limestone, and often attains a larger size than in that rock. Figs. 4 a, b. Casts of the interior of the dorsal valve. Fig. 4 c. Cast of the interior of the ventral valve. Fig. i d. A similar cast, more strongly impressed by the stria. Fig. 4 e. A fragment of the impression of the outer side of the ventral valve, showing the fine concentric strise, which crenulate the diverging stri^. These forms are the common ones in the shales and shaly sandstones of this group. It is rarely that we find casts in the Trenton limestone, and almost equally rare to find the shell preserved in this group. In this condition, it presents some slight differences from the same shell in the limestone below ; but it is by no means a distinct species, as has been represented. Position and locality. This species rarely, or never, appears in the Utica slate, but re- appears near the middle of the Hudson-river shales, and continues nearly to their termination ; being abundant at Turin, Loraine, Pulaski, and other places. It is more rarely found in the vicinity of the Hudson river, and in the Mohawk valley. (State Colltction.) 341. 19. ORTHIS? ERRATICA (71. s;j.). Pl. LXXIX. Figs. 3 a, b, c, d, e,f. Subhemispherical, orbicular ; dorsal valve very convex, with the mesial portion abruptly elevated, flat above ; ventral valve convex at the sides, depressed in the middle, and considerably elevated in front ', surface marked by fine simple uniform strire. This species is usually found in great numbers, in erratic masses of the sandstones of this formation, associated with Orthis testudinaria, Cyrtolites ornatus, and other fossils of the group. It has rarely been found in the rocks in place. It is distinguished from Orthis testudinaria, which it most resembles, by its more rotund form, and broader mesial elevation and depression ; the strias are also more simple and straight, scarcely curving towards the cardinal margin. It is unknown in the Trenton limestone. Figs. 5 a, b. Dorsal and ventral views of the cast of a large specimen. Fig. 5 c. Ventral view of a small specimen. Fig. 5 d. Front view of a larger specimen. Fig. 5 e. Cardinal view of a large specimen. Fig. 5/. Profile view of a moderately convex specimen. HUDSON-RIVER GROUP. 289 Position and locality. Near Washingtonville, Oswego county, in the central part of the g^roiip, and in transported fragments in all the southern counties of the State ; often abundant. {State ColUttUm.) 342. 20. ORTHIS CENTRILINEATA (h. syj.). Pl. LXXIX. Figs. 5 a, b, c. Semioval ; length and breadth nearly equal ; dorsal valve moderately convex; stri* about thirty, bifid or trifid towards the margin ; cast of the visceral impression bilobate, small, narrow, sublinear, with a depressed line extending from the centre towards the base of the shell. The specimens of this species yet seen are casts, with a small portion of the shell remaining. It approaches more nearly to 0. dichotoma of the Trenton limestone, than to any other species known to me; but the strias are more numerous and often trifid, and the dorsal valve less convex. It is readily distinguished from 0. tcstudinaria, with which it is associated, by the slightly elevated convex valve, and the stronger radiating stria;, which show no evidence of concentric striaj. It bears some resemblance to Orthis vespertilio of MuRCHisoN, but is uniformly smaller, and evidently distinct. Fig. 5 a. A specimen of the natural size. Fig. 5 b. A magnified portion of the cardinal line, and visceral impression. ; Fig. 5 e. Several striae enlarged, showing the bifid and tiifid character. Position and locality. This species is found associated with Orthis tcstudinaria, Trinucleus, and crinoidal colunms, in the higher part of the group, at Lorainc, Jefferson county, and at Turin in Lewis county. {State Collection.) 186. 19. ATRYPA INCREBESCENS. Pl. LXXIX. Fig. C. _ ' . _ Refeience pag. 146, pi. 33, figs. 13 a - y, of this volume. This species is of frequent occurrence in the lower part of the Hudson-river group, rarely attaining a larger size than the figure given. It is always crushed, and is not readily recognized as identical with that of the Trenton limestone. Position and locality. In the Utica slate, at Turin, Lewis county, and in the shales of the Hudson-river group at the same place, and at Loraine. {State Collection.) In addition to the preceding forms, the Mrypa modesta ( see page 141 ) occurs in the upper part of the Utica slate ; and very rarely fragments or casts of some other Trenton limestone species are found, either in this slate or in the Iludson-river group. They are, however, by no means characteristic of the rocks of this formation. I P.tL.EONTOLOGY.] 37- 290 PALEONTOLOGY OF NEW-YOHK. 343. 5. ORBICULA? SUBTRUNCATA («. *j5.). Pl. LXXIX. Figs. 7 a, ft. Ovate-orbicular, depressed, marked by fine concentric striae ; apex small, excentric ; the broader extremity often subtruncate, having an appearance like Metoptoma. This species is abundant in some localities, covering large surfaces of the shaly sandstones, or distributed through the mass. In the latter condition it is obscure and not readily detected. Fig. 7 ffl. A small fragment, with several individuals of this species upon the surface. Fig. 7 b. A. single specimen, enlarged. Position and locality. In the central and upper part of the group, at Loraine and Turin, and probably at other places. {State Collection.) 344. 6. 0RBICULA1 CRASSA (n. s;).). Pl. LXXIX. Figs. 8 a, b. Ovate-orbicular, with the apex near the narrower extremity ; apex obtuse ; surface marked by strong concentric wrinkles, ond fine radiating striae. These characters are preserved in the cast, a small portion only of the shell remaining upon the specimen. Fig. 8 a. The specimen of the natural size. Fig. 8 b. A part of the surface enlarged, showing the concentric and radiating lines. Position and locality. This species was found in the intercalated calcareous strata, among the shales of the Hudson-river group, two miles northeast of Troy. 345. 7. ORBICULA CiELATA (n.sp.). Pl. LXXIX. Figs. 9 a, ft, c. Orbicular, small ; apex excentric, depressed along the centre, and subplicated near the margins; surface marked by fine concentric lines and minute elevated points, giving it the appearance of being covered by a poriferous coral. This species is readily distinguished by the fine papillose markings, which sometimes appear as if depressed at the tip, resembling in some degree the surface of the 0. punctata of MURCHISON. Fig. 9 a. A fragment of this species. Fig. 9 b. The fragment enlarged, to show the central depression and lateral plications. Fig. 9 c. A portion of the surface still farther enlarged, showing the character and arrangement of the papilliE. Position and locality. The fragment figured is from the limestone intercalated with the Hudson-river shales, near Troy (from Dr. Skilton). I have a similar perfect specimen, which occurs in the shales of the Blue limestone of Ohio, from Mr. Clarke, of Cincinnati. tTICA SLATE AND HUDSON'-BrVER GROUP. 291 ACEPHALA OF THE UTICA SLATE AND HUDSON-RIVER GROUP. Plates LXXX., LXXXI. & LXXXU. Among the Acephala, not more than tliree species are known in the Utica slate ; and these, with one exception, are continued into the higher shales. In the shales, and argillaceous and calcareous sandstones succeeding tho black slate, we find a considerable accession of species, which are unknown in the limestone below. At tlie same time, several species are common to the limestones and the succeeding shales and sandstones. The Genus Avicula, of which the species in the limestone are somewhat equivocal, becomes well characterized in two species. The Genus Ambonychia is represented by two species quite distinct from those in the lower strata ; and the Genus INIodiolopsis presents very characteristic forms, which are much more numerously developed than in the inferior limestone. In addition to these, there are two or three other forms, presenting generic characters not observed in those previously described. Two of these ( Orthonota and Cleidophords ) become more distinctly developed in succeeding formations. The comparative abundance of species and individuals of the Brachiopoda and Acephala in these strata may be readily appreciated by reference to the plates (79, 80, 81 and 82), where the species of each are represented. 346. 3. AVICULA INSUETA. Pl. LXXX. Figs. I a,b. Avicula insueta. Conrad in MS. — — Emmons, Geol. Report, 1S42, pag. 399, fig. 5. Shell obliquely subrhomboidal, depressed convex ; hinge line extended ; anterior wing short, obtuse or rounded ; posterior wing triangular, acute, extending a little beyond the margin of the shell ; surface marked by imequal concentric striae and stronger wrinkles, and longitudinally, along the middle of the shell, by obscure radii. This fossil bears some resemblance to other species of the genus in the higher strata, but differs essentially on a careful comparison. . " • • Fig. 1 a. A specimen, natural size. 1 *. A portion of the surface enlarged. Position and locality. This species occurs in tiie lower black shale, or Utica slate, at Canajoharie, and is not known in the higher part of the group. (State Collection ) 37' 292 PALEONTOLOGY OF NEW-YORK. 347. 4. AVICULA DEMISSA. Pl. LXXX. Figs. 2 a, b. Avicvla demisfa. Cois-rap, Jour. Acad. Nat. Sciences, 1S42, Vol. viii, pag. 243, pl. 13, fig. 3. — Emmons, Geol. Report, 1S42, pag. 404, fig. 2. Obliquely suiiovate, compressed, extended posteriorly into a broad triangular wing ; anterior wing short, obtuse ; surface marked by close, sharp, imbricating, lamellose striae ; posterior wing extending beyond the line of the posterior extremity of the shell ; anterior and posterior margins nearly parallel, and but slightly oblique. This species is characterized by the sharp elevated concentric strias, which arc crowded together on the posterior wing, and at its jimction with the body of the shell. The shell presents some variations in form, bnt preserves the sharp striee in all the specimens seen. Fig. 2 n. A large perfect specimen, which is more elevated than usual. Fig. 2 b. The impression of a smaller specimen in sandstone. Position and locality. This species is found in the higher part of the Hudson-river group, near Rome, Oneida county, and at Pulaski. It likewise occurs in the same position in Ohio. Rolled fragments of the calcareous portions of the group, containing this shell, are frequently found on the south shore of Lake Ontario. (State Collection ) 348. 5. AVICULA 1 DESQUAJWATA. Pl. LXXX. Figs. 3 a, b. Suborbicular, convex in the middle ; beak nearly central ; hinge line slightly extended on each side ; surface scaly, or with elevated imbricating lamellae, which desquamate, giving the surface a rough scaly appearance. The characters of this species are not clearly decided, though it appears referable to the Genus Avicula. Fig. 3 a. A specimen, natural size. 3 b. An enlarged portion of the surface. Position and locality. This species has been found only in the calcareous beds associated with the shales of the Hudson-river group, near Troy. 349. 7. AMBONYCHIA RADIATA. Pl. LXXX. Figs. 4a-/. Pterinea carinata. Conhad, Ann. Geol. Report, IS3S, p. 114; 1839, p. H.3. — — Vanuxem, Geol. Report, pag. Ci5, fig. 1. — — F.MMONs, Geol. Report, pag. 402, fig. 1. Compare Pterinea carinata, Goldfuss, Vol. ii, pag. 13(5, tab. 119, fig. S. Equivalve, obliquely obovate, extending into acute curving beaks ; anterior slope nearly straight above, and rounded below ; posterior slope oblique, scarcely alate ; surface marked UTICA SLATE AND HUDSON-RIVER GROUP. 293 by ttventy-five to forty strong simple radii, whicii are crossed by fine concentric striae ; radii flattened upon the top ; the intermediate spaces are regularly concave grooves, narrower than the radii, and marked by the concentric striae. Tiiis species has usually been referred to Pterinea carinata of Goldfuss, but it appears to me specifically distinct. The figure of that author, which is larger than figs. 4 a, 6 of our plate, represents the shell as iiaving twenty-three or twenty-four radii, which are proportionally stronger than in this shell, while specimens of equal size with the figure of Goldfuss have from thirty-five to forty radii upon each valve. On this account, principally, I am disposed to consider the succeeding species as identical with that of Goldfuss. I regard both this and the following species as differing sufficiently from Pteeinea of Goldfuss to be separated from that genus, and to constitute species under the Genus Ambonychia, which is destitute of an anterior wing, while the posterior side is expanded, thouf^h scarcely alate, never showing the distinct wing which marks the Avicula and nearly all the species of Pterinea. Fio'. 4 a, b. The right and left valves of diflerent specimens of this species. Fio-. 4 c. A smaller individual, with the radii distinctly marked, and more than thirty in number. Fi.) Pi,. LXXXII. Figs. 5 a, b. Subelliptical, length nearly once and a lialf the width ; beaks elevated ; cardinal margin a little declining posteriorly ; front rounded ; a shallow sinus extending obliquely backwards from the beak to the base, producing an indentation in the basal margin ; surface marked by concentric folds, which are undulated on tiie sinus. tJTICA SLATE AND HUDSON-RIVER GROUP. 299 This species is very distinctly characterized by tlie ol)lique impression or sinus, wliirh produces an indentation in the basal inarj^in, and often leaves the posterior extremity acute. iPig. 5 a. A specimen preserving both valves. Fig. 5 b. The right valve, which is less compressed than the preceding. Position and locality. This species occurs in the Utica slate, at Turin, associated with the Graptolites ; in the same position in Montgomery county ; and in the black, glazed, and partially mctamorphic slates of Waterford, Saratoga county. 357. 1. ORTHONOTA PHOLADIS. Pl. LXXXII. Fig. 6. ■ . - Pterinea pholadis. Conrad, Ann. Geol. Report, 1S3S, p. 118. Orthonota pholadis. Id. lb. 18J1, p. 151. " Shell profoundly elongated, ventricose; dorsal and basal margins parallel ; posterior side rugose, or with short undulations near the dorsal margin. Length If inches." The preceding description is cited from i\Ir. Conrad, and the figure is also by him, having never seen the shell myself. It resembles the following species, but is much more elongated and proportionally narrower. Position and locality. In the shales of this group at Pulaski, Oswego county^ 358. 2. ORTHONOTA PARALLEL A (ji.i/j.). Pl. LXXXII. Figs. 7 a, ft, c, d. Shell extremely elongated and very narrow ; anterior extremity rounded, and contracted just forward of the beaks; cardinal margin straight or gently arched ; posterior extremity rounded, broader than the anterior ; basal margin slightly arcuate ; beaks near the anterior extremity having an obscure carina, extending obliquelj' towards, l)ut not reaching, the posterior basal margin ; surface marked by fine concentric stria;, and a few obli(|ue strong wrinkles along the dorsal margin. This shell bears considerable resemblance to the 0. pholadis ; but is less extended, and has a greater width. The width in this species is fully one third the length, while in the figure of 0. pholadis the width is less than one fourth the length. In specimens which are imbedded in shale and much compressed, the surface is regularly convex, and the oblique elevated carina becomes obsolete. The cast is smooth, with scarcely any evidence of the oblique folds on the cardinal margin. Fig. 7 a. The left valve, preserving the shell, which is finely striated concentrically, and shows the folds upon the cardinal line. Fig. 7 b. Dorsal view of a cast in coarse sandstone, where the folds are visible on the dorsal margin. Fig. 7 e. The left side of a cast scarcely retaining any markings. Fig. 7 d. Dorsal view of the same. The anterior extremity is partially eroded. 38» 300 PlLjEONTOtOGY OF NE*-YO»K. Position imd locality. This species occurs in the soft shaly portions of the group, at Pulaski, Loraine, and other places. I have obtained casts of the same from the ferruginous sandstones in the higher part of the group. It occurs likewise at Cincinnati, and several other western localities. 359. 3. ORTHONOTA CONTRACTA (n. SJ3.) Pl. LXXXII. Figs. 8 a, b. Subcylindrical, slightly arcuated ; beaks distinct, acute, with a prominent oblique carina extending towards the posterior basal margin, which is arcuated, and the shell much contracted below and posterior to the beaks ; dorsal margin broad, rounded, the valves strongly marked by oblique folds. The extremities of the shell are wanting in the two specimens which I have. It differs from the last, in liaving more acute and distinct beaks, with the cardinal margin broader. The base is arcuate, and distinctly contracted, or sinuate, a little behind the beaks. It is possible that this may prove identical with the last, since I have been unable to examine perfect specimens. Fig. 8 a. The left valve, showing the distinct carina and concentric striae of the surface. Fig. 8 b. Dorsal view of the same, showing the oblique wrinkles on the posterior cardinal margins of the shell. Position and locality. This species occins in the soft marls at Cincinnati, Ohio. I have not seen it from other localities. 360. 1. CLEIDOPHORUS PLANULATUS.* Pl. LXXXII. Figs. 9 a, b, c, d, e. JVuculiies planulata. Cowbad, Ann. Report, IS41, p. 4S. — scitula. Conrad in MS. Emmons, Geol. Report, pag. 399, fig. 2. Subelliptical, with the anterior extremity narrowed, regularly rounded ; posterior side broader ; beak scarcely elevated ; a distinct impressed line extending from before the beak, • All the specimens of this species which I have examined, show no crenulations upon the cardinal margin, which is nearly direct and subalate posteriorly. There is no visible muscular impression as in Modiolopsis ; and the strong linear depressed line in the casts indicates the existence of a rib, or clavicle, as in Solecurtus. This character, which is very conspicuous in several species in the higher strata, pertains to shells having a similarity of form, which is nearly like the one figured. For shells of this character, I propose the following generic name : Genus CLEIDOPHORUS. [Greek, xXfi^og, clavicle, and (p£po, to bear; in allusion to the clavicle in each valve, anterior to the beak.] The shells of this genus may be characterized as, equivalved, inequilateral; hinge without teeth or crenulations; surface (particularly in casts) marked by an oblique linear depression, extending from the anterior cardinal margin towards the base, indicating the place of the clavicle ; surface concentrically striated. tTICA SLATE AND HUUSON-RIVER GROUP. SOl halfway lo tlio l)ase ; hinge line straight; posterior extremity obliquely truncated ; shell uniformly convex ; a round elevated ridge extending from the beak to the posterior basal margin, between which and the cardinal line a narrow portion of the shell is closely compressed. This species is very abundant in the green shales just above the black shale, and is also often found in the higher arenaceous parts of the group. The thin compressed portion on the posterior dorsal margin is often covered, so that the form is the same as lig. 9 a, which shows only the convex part of the shell. Sometimes the impressed line before the hinge is not distinctly visible, particularly in the folded and glazed slates of this group along the Hudson river ; but in most instances it is a reliable character. In the decomposing arenaceous portions of the group, this is one of the most abundant fossils, associated with crinoidal joints, fragments of Trinudeus, and other fossils. Fig. 9 a. A specimen of the arenaceous slate, with several individuals of this species, associated with crinoidal columns, etc. Figs 9 b, c, d. Other individuals from different localities, showing a slight difference in form. Fig. 9 e. A specimen from the altered slates, preserving both valves. In its geographical distribution, this species is coextensive with the group, and is un- known below the Utica slate, or above the terminal sandstone of the Iludson-rivcr group; Position mid locality. This species occurs in all parts of the group, in the following localities : Turin and Martinsburgh, Lewis county ; Loraine, Jefferson county ; Pulaski and Washingtonville, Oswego county ; near Rome, Oneida county ; Waterford, Saratoga county, and other places. 190. 2. iNUCULAI POSTSTRIATA. , . . - • Pl. LXXXII. Figs. 10 a, b. Reference pag. 151, pi. 34 of this volume. . . This species has already been given under the Trenton limestone, where it first occursi In the Hudson-river group it acquires a greater development, and is both larger and more numerous. It rarely preserves the shell, however, and we are forced to depend on casts of the interior for our examinations. The strong diverging stria; upon the posterior slope are usually marked upon the cast, which, with the subtriangular form of the shell, is suflicient to distinguish it from others of the group. The broader or more quadrangular form of the specimen in the Trenton limestone is due to the preservation of the shell, which gives the posterior slope a greater elevation. Fig. 10 a. A small specimen in the ferruginous sandstone. Fig. 10 i. A larger specimen, preserving very distinctly the stria; on the posterior slope. Position and locality. This species occurs both in the shaly and arenaceous part of the group, at Loraine and Pulaski, though it is a comparatively rare form, instate Collection.) 302 paleontology of new-york* Genus LYRODESMA (Conrad). Character. " Equivalved, inequilateral; hinge with about eight diverging; prominent cardinal teeth, transversely striated." If this description, cited from Mr. Conrad, were so altered as to include shells with a greater number of cardinal teeth, it would include a species which appears Closely allied to the one described as the typical form. The form of this shell, and character of the diverging cardinal teeth, or crenulations, are different from Nucula, and more nearly like Pectunculus. I prefer, however, to place it under the Genus Lyrodesma, provisionally ; though a better knowledge of L. plana, the typical species of the genus, may hereafter render it necessary to separate them. 361. 1. LYRODESMA PLANA. Pl. LXXXII. Figs. 11 a, ft. Lyrodesma plana. Conrad, Ann. Geol. Report, 1811, p. 51. " Subrhomboidal, compressed ; posterior margin widely and obtusely truncated ; posterior basal margin rectilinear; extremity rounded." I have copied the figures and description of Mr. Conrad, not having seen the shell. It is described in the Annual Report cited above, and also figured on a plate partially prepared for his report on palaeontology. Fig. 1 1 a. The right valve. 1 1 b. Interior of the right valve, showing the cardinal teeth. Position and locality. In the shaly sandstones of the Hudson-river group near Rome, Oneida county. 362. 2. LYRODESMA PULCHELLA. Pl. LXXXII. Figs. 12 a, b, c, d. Slightly inequilateral, broadly oval ; beaks moderately elevated ; anterior extremity rounded; posterior extremity scarcely truncated ; hinge line gently arched, marked by about eight diverging teeth on the posterior side of the beak, and apparently fewer ( five or six ) on the anterior side ; surface marked by fine equal concentric striee. This is the most beautiful shell among the bivalves of this group ; its nearly symmetrical form, finely striated surface, and crenulated hinge line, are sufficient to distinguish it from any other species. It is usually compressed, and but slightly convex ; hut wlien found in a perfect condition it is very convex, and even ventricose towards the umbones. Fig. 12 a. A specimen of the natural size, from the black slate near Watertown, Jefferson county. Fig. 12 b. The same enlarged, showing the character of the crenulations. Fig. 12 c. A smaller specimen, from the partially altered slates near Waterford, on the Hudson river. Fig. 12 d. The cardinal line enlarged. Position and locality. This species occurs in the loWer part of the group at Turin, and near Watertown, in the unaltered slates; and near Waterford, in the black glazed slates of the same group. HUDSON-RIVER GROUP. 303 GASTEROPODA OF THE HUDSON-RIVER GROUP. Plates LXXXIII. & LXXXIV. Among the Gasteropoda of the Utica slate and the succeotling shales and sandstones, there are few forms with which we are not already familiar in the Trenton limestone. In the lower black slate we rarely find specimens of this order, a single species being all that I have observed. In the succeeding strata we find a single well marked species of Bellerophon, differing from those of the Trenton limestone ; and that peculiar form, the Cyrtolites ornatus, which is unknown in any other position. A very small proportion of the species known in the limestone reappear in this position, and in nearly all instances the specimens are but poorly preserved. I have introduced a single well marked and characteristic species from the western extension of the group, though it has not been distinctly recognized in New-York. Almost all the specimens occur in the form of casts of the interior, ti»e shell being rarely preserved; in consequence of which, there is some difficulty in identifying them. 236. 13. MURCHISONIA GRACILIS. Pl. LXXXIII. Figs. 1 a, 6. , Reference Murchisonia gracilis, pag. ISl, pi. 39, figs. 4 a, b, c, of this volume. I am unable to find any marks of distinction between the slender forms so common in the Trenton limestone, and those in the shales of the Hudson-river group, which will enable me to refer them to distinct species. There are some slight variations observable even in specimens from the same rock ; but these appear to be due to accidental causes, or the different chararter of the enclosing material. This species is abundaiU in tlie shales and calcareous portions of the sandstones of tliis group, but I have never been able lo obtain one where the shell is preserved. Fig. 1 a. A specimen (a cast) from the calcareous sandstone. Fig. 1 ft. A similar cast from the soft shales, at Loraine. Position and locality. This species occurs throughout the group, and is one of the most coiumon forms at Turin, Loraine, Washingtoin illc, Pulaski, and Rome. It is also found in the altered slates of the group, on the Hudson river, near Waterford. (State Collection.) 304 PALJEONTOLOGY OF NEW-YMIK. 363. 14. MURCHISONIA UNIANGULATA, var. ABBREVIATA. Pl. LXXXIII. Figs. 2 a, b, c, d. Compare Murchisonia uniangulata, pag. 179, pi. 3S, fig. 8, of this volume. Conical or subfusiform ; volutions about four or five, rapidly diminishing from the apex ; last whorl angular on the middle ; centre of the whorls marked by a double depressed spiral band, separated by a narrow space, which is not marked by the striae ; surface marked by fine striae, which form a deep retral bend on the body of the whorl where they meet the spiral band. This species resembles, in form, the M. bicarinata of the Trenton limestone ; but it differs essentially in having the volutions angulated only on the centre. The specimens of this species which occur in the Hudson-river group, are all shorter than the M. uniangulafa of the Trenton limestone. The carinal band in that species is obscure, and I cannot decide whether it be double, as in the specimens under consideration. Figs. 2 a, b. Two specimens which preserve a part of the shell. Fig. 2 e. A portion of the surface of the last volution magnified, showing the double spiral band. Fig. 2 d. A specimen with the volutions more acutely angulated, but apparently identical. Position and locality. In the calcareous higher portions of the group at Turin, Lewis county, and in a similar situation near Rome, Oneida county. {State Collection.) 225. 13. PLEUROTOMARIA SUBCONICA. Pl. LXXXIII. Figs. 3 a, b, e, d, e. Reference Plevrotomaria siibconica, pag. 174, pi. 37, figs. 8 a, b, c, d, of this volume. This species is not unfrequently found in the shales of the Hudson-river group, but usually in such a condition as not to be readily recognized. All the specimens yet seen are casts, preserving in one or two instances some remains of the vertical striae and the carina, upon the centre of the last volution, It can be recognized by its almost uninterrupted conical form and broad volutions, with a prominent carina on the last one, which is pre- served in the casts, while the higher volutions are obtusely angulated near their base. I have received specimens of the same species from the northwestern part of Wisconsin, collected by the late Mr. Nicollet. Fig. 3 a. A specimen preserving the vertical strife. Fig. 3 A. A portion of the same enlarged. Figs. 3 c, d. Imperfect casts, from the shales of the Hudson-river group. Fig. 3 e. A more perfect cast of the same species, from Wisconsin. Position and locality. Tliis fossil occurs in the central portions of the Hudson-river group at Turin, Pulaski, and otiicr places in tiie State of New- York. The western specimens are in limestone, associated with other fossils known as belonging to the Trenton limestone. {State Collection.) HUDSON-RIVER GROUP. 305 - 364. 17. PLEUROTOMARIA[?] BILIX. Pl. LXXXIII. Figs, i a, b, c, d, e. Plenrotomaria bilix. Conrad, Jour. Acad. Nat. Sci. Philadelphia, lS-12, Vol. viii, pag. 21\, pi. 16, fig. 10. Compare Pleurotomaria percarinata, pag. 177, pi. 38, fig. 4, of this volume. Obliquely conical ; spire short, composed of four or more voluiions, wliicli are somewhat appressed above and ventricose below ; last volution somewhat flattened on the lower side ; aperture rounded, or sliglilly transverse ; surface marked by numerous strong spiral carinae, which frequently alternate with finer ones ; these are crossed by fine stri a, b, c 1 a, b 8 a- e 9a-g 10 a- e 11 a. A, c 12 a, 6, c xxxii, 13 a, b xxxii A, 1 xxxii A, xxxii B, xxxii B, xxxii c, Ixxix, Ixxi .X 2 a- q \ a - e 2 a- s 1 a - m 5a-/ 6* a, 6, c xxxii D, iv bis, iv bis, iv bis, iv bis, iv bis, xxxiii, xxxiii, xxxiii', 1 a- u 6 7 a - e 8 a- dl 9 a- d 1 a, b 2 a,b, c 1 a-h 290 290 290 19 19 20 102 2S6 lOti lOfi lOS 109 110 287 111 112 113 113 114 115 115 116 20 117 2S8 118 118 119 120 120 121 121 122 123 124 125 125 126 127 128 12S 129 2S8 2S9 i:):j 21 21 21 22 23 137 1.38 138 Rocks & Groups. + + + + ' Erroneously referred to fig. 5 on page 289. t J?, cuspidata figured on supplementary plate xxxiii* TABLE OF SPECIES. GENERA AND SPECIES. Atrv]>a bisulcata, Kmmons , — deflecta, HaU . — lecurvirostra, — cxii^ua, — modesta, f-'ai/. — circulus, — ambi;4ua, '• — lierniplicata, *' — up. btilct — sublrigonalis. Hall — increbescens,* U) 11 12 13 11 15 — 10 — n — IS — 19 — ■20 — 21 — dentata, sordida. 1 2 — 3 — 4 — 5 — U — Ha' I ACEPHALA. Ambonychia mytiloides, — bellastriata, " — orbicularis, Conrad . . — amygd-ilina, i/a// . ... — luidata, Conrad obtusa, HaU — : sp. indit . — radiata, /faW — carinata, Goldfuss . . . . Avicula trentonensis, Conrad . , — elliptica. Hall — insueta, Conral — demissa, " — ? desquaniata, Hall Modiolopsis mytiloides. Hall . . . — parallela, Conrad — faba, " nasutus. 5 — arcuatus. Hall 6 — subspatulatus, " .... 7 — latus, " . . . . 8 — carinatus, " . . . 9 — aviculoides, " . , , . 10 — trentonensis, Conrad . , . 11 — modiolaris, *' . . 12 — truncatus. Hall 13 — curta, Conro'i 1 4 — sp. indet " — terminalis, //«W 1;'> — anodontoides, Conrad ... Ifi — ? niiculiformis. Hall 1 Moiliola ? obtusa, " . . . . 1 Tellinomya nasuta, Hall.... 2 — sanguinolaroidea, " ... 3 — ffibbosa, " ... Plate and figure. XXXIll xxxvi, xxxvi, xxxvi, xxxvi, xxxvi, XNXvi, Ixxx, Ixxx, xxxvi, xxxvi, Ixxx, Ixxx, Ixxx, XXXV, XXXV, ', XXXV, [ Ixxxii, J XXXV, [ Ixxxi, XXXV, XXXV, i a - c 5 a - (i a a- c 1 a,b S a, b 0 a,b 4 a- m 5 a, b 2a-d 3 1 a. b 2 a, 6 ■J a. i a. 5 0 a- 4 7 •2 8 9 a. XXXV, 10 a, b XXXV, 11 a - c 1 o, 6 10 Ixxxi, 1 ; Ixxxii, 1 Ixxxi, 3 a. b Ixxxi, 4 ; Ixxxii, 2 ■ Ixxxi, 5 a, b XXXVI xxxiv 3 a-c 4 a, b 5 a, 6 Page. 1.39 IJO 140 Ml 141 142 143 144 14.'j M.O 140 289 148 113 315 163 164 165 165 107 107 292 294 161 162 291 292 292 l.-)? 158 1.58 298 159 296 159 159 160 160 101 101 294 296 297 297 ; 318 < 208 ' 293 40 152 152 153 Rocks tc Grovp9. + + +'■ + + + + + + + + + + + + + + + + + + + + + + + + + + + • • + + + + + + + + Compare .3. capax, Conrad, Jour. Acad. Nat. Sciences, Vol. viii, pag. 204, pi. 14, fig. 21. 41-2 326 PALEONTOLOGY OF NEW-YORK. GENERA AND SPECIES. Tellinomya dubia, Ha/t — anatiniformis, " Orthcnota pholadis, Conrad — pavallela. Hall — contracta, " Ck'idophoi'us plaiuilatus, Conrad . Nucula levata, Hall — [■'] poststriata, Conrad — f donaciformis, Hall . Lyrodesma plana, Conrad. . . — pulchella, Hall Cardiomuipha vetusta, " Edmondia ventvicosa, " — subtruiicata, " — ? siibangulata, *' 1 1 •2 1 2 3 1 2 3 4 1 1 1 1 2 1 2 3 4 1 o 3 4 .') (J 7 S It 10 11 12 13 It IT) 10 17 IS GASTEROPODA. Enomphulus uniaiia;ulatus, Hull . . . Ophileti levata, Vanuxcm — complanala, " Maclurea sovdida. Hall — matulina, " — !nai^na, Leseticr Raphisloma striata, Kmmons — staminea. Hall — planistiia, " — — var. [invvd, Hall , Scalitps angulaliis, Conrad Capuhis auritbrmis, Ha// Natica .' (sp. indrt ) Tuvbo dilucula, Hall — ? obscura, " Holopea symmetrica, Hall • — obliqua, " . . ., — paludiniformis, " . . . . — vtintricosa, " . . . . Pleurotomaria? turgida, " .... — biangulata, " .... — (sp. indit.) — antiqiiata, H
us sandstone, sandstone. 1 I Miirchisonia abbreviata. Hall vi, 7 32 ....+ 2 — .' angustata, " X, 2 a, i 41 + 3 — vcntricosa, " X, 3 41 + .. 4 — perangulata, " X, 4 41 +...-.... 5 — .' varicosa, '* X, 7 a, i 42 +..., t) — bicincta, " xxxviii, .'i a - h 177 .. + .... 7 — tricarinjta, " xxxviii, ii a ~ r. 178 +.. .. 8 — peranKiilata, t)«r. .\., y/u// .. xxxviii, 7 a, 6 i7y + .. .. 9 — uiiiangulata. Hall xxxviii, ft 179 + .. .. 10 — bcUacincta, " xxxix, 1 n - f 179 •• 4 .. .. U — subrusiformis, " xxxix, 2 a, b ISO + .. .. 12 — vittata, " xxxix, 3 a, 6 181 + .. .. 13 — gracilis, " ( xxxix, 4 a - c I Ixxxiii, 1 a, 6 303 5 •■■•••••••+■■ + 14 — uniangulata, var. abbreviata. Ixxxiii, 2 a - rf 304 .. + 1 Subulites elongata, Corirad xxxix, 5 a - c 182 ....-•.... + .... 1 Metoptoma ? dubia. Hall iv bis, 11 23 ....+ 2 — .' rugosa, " 1 Carinaropsis carinata, ** Ixxxiii, ij a - f xl, la-c 30G + 183 +.. .. 2 — patcUiformis, " 3 — orbiculatus, " 1 Bellerophon bilobatus, Sowerby ( xl, 2 a, i ( Ixxxiii, 7 Ixxxiii, 8 a - c (xl, 3a-(i ( Ixxxiii, 'J a - e xl, 4 a, * 1S3) I. , 3oe 5 ^ ^ 184 +• -. 2 — — tiar. acutus. Hall.. isr, + ■•.. 3 — — var. corrugatus, " xl, 6 a, b Ixxxiii, 10 a - i; vi, 10, 10 a vi, 11 a - c xl, 1 a-d 18.') +■■ •• 32 ••••+ ••.. 33 .. .. + •• .. 186 + •• .. 2 — rotundata. Hall 3 — expansa, ** 4 — bidorsata, " xl, 8a-g ISO .. + •• .. 5 — piinctifrons, Conrad, £mm.. (J — intexta. Hall xl A, I a - e xxxiii*, 4 a - d xl A, 2 a -/ 1S7 -\- ... 317 +•• .. 188 +••■■ 1 Cyrtolites compressus, Conrad 2 — trentonensis, " .... xl A, 3 ; xli, 1 189 +"•• 3 — filosum, " xli, 3 a, 4 190 -.........+■■.. 4 — ornatus, '• Ixxxiv, 1 a - g 308 ■■ + CEPHALOPODA. xiii, 1, 3; xiii bis, 1 xiii, 2, 2 a r)2 • • +...... .03 •• +..•• . 2 — coiivolvans ? Hisinger 1 Trocholites ammonius, Conrad f xl A, 4 a -A: 5 Ixxxiv, 2 a - c Ixx.xiv, 3 o -/ l'-'2) ..+..+ 309 5 ^ ^ 2 — planorbiformis, " .... 310 ......+ ORTIIOCER.\TA. 1 Oncoceraii constrictiim. Hall xli,0 a-f, 1 a-d 197 -f .. .. 1 Cyrtoceras lamelldsuin, " ... .- xli, 2 a - c 193 •• +■• ■• 2 — annulatum, " xli, 4a-d, f, 194 • +.. •. 3 — macrostomum, '* xiii, 1 a - c, 3 a, d 194 •• +■• •• 4 — constrictostriatum, " xiii, 2 a,b; 3 c,d 195 •• ..+.... 5 — multicamcratum, " xiii, 4 19S •• •• •• +•• •• 6 — arcuatum, ** xiii, 5 a - i; 19(5 . ........ ^.. .. 7 — camurum, " xlii, 6 196 •-.••• • .. + 1 Orthoceras primigcniutn, Vanttxem.. iii, 11. 11 a 13 ..+............ 2 — laqueatum, Hall iii, 12; Ivi, 2 a - c 3,206-- +--J-- .. +|-- ••! 328 PALEONTOLOGY OF NEW-YORK. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 9 10 11 12 13 U 15 IG 17 18 1 1 GENERA AND SPECIES. Orthoceras rectiannulatum. Hall — subarcuatura, " — teiuuscptum, " — (Ormoccras) nioniliforme, ' Conrad Hall . muUicameratu recticameratum fiisiforme, " arcuoliratiiiM. " teretiforme, " textile, " bilineatum, " — var. a. " clatliratum, " vertebrale, " ■anellum, Conrad ... undulostriatum. Hall {sp. indet.) . latiannulatum, Hall junccum, " amplicameratum, *' strigatum, " laqueatiiin, var. a. " (sp. ijidet.) coralliferum, " lamellosum, " 1 Ormoceras tenuifilum, — — var. distans, — .' gracile, " — crebrisaptum, " Endocevas subcentrale, " — longissimum, " — multitubulatum, " — gemelliparum, " — annutatum, " — proteiforme, var. temiistiiatum, — var. tenuitcxtum. Hall — var, lineolatum, " . — var. strangiilatura, " , — var. elnngatum, " , — arctiventi'um, Hall . — angiisticamcratum, " — magniventrum, " — — var. " — appioximatum, " — duplicatum, ** — distans, " — protcif'urmc ? Cameroceras trentoncnsc, Conrad. Gcmiocpras anceps, Hall Plate and figure- VII, vii, vii, vii, xi, xi, XX, xlii, xlii, xliii, xliii, xliii, xliii, xliii, xliii, xliii, xliii, liv, xlvii H, Ivi 2, 2 a 3 6 5 1 a, b, c 1 d 1 1 a - c 8 a,b 1 a, b ■2 a- d 3 a - il A a - c 5 a - c 6 a -/ 7 a -A- 8 1 a, b , 3 a-/ 1 a- g 1 a - d xviu xviii xix, xlv, Cxlv, Ivi, 3 Ixxxv, 2 Ixxxv, 3 ; Ixxxvi, Ixxxvi, 2 a ~ d ( XV, 1 ; xvi, 1 : xvii, ( Iviii, 2 a, b xvii, 2 xvii, 3 Ixxxvi, 2 ; Ixxxvii. xvii, 4 1, 1 a 2 a, b 1 a, b 1 a, b I a,b ^ xlvii, 1, & 2 a - e ^xlv, 2, 3, & 5a-c ( xlviii, 2 a - c i xlv, 4 a - e ^xlvi, 1,2,3 (xlvii, 4 a - e xlvi, 4 a - e Hi, 1 a, b 2 a,b 3 1 a ~ e 2 b 2 a 1 1 a, * Ixxxv, 1 a -f Ivi, 4 a - c xiv, I, I a - d li, li, liii, liv, liv, Iv, Ivii, Page. 34 34 35 35 45 46 60 198 198 199 199 200 201 201 202 202 203 204 204 205 205 206 311 312 312 55 222 58 58 313 59 59 59 60 207 209 210 211 212 216 217 218 218 218 219 219 220 311 221 54 Rocks & Groups. + + + + TABLE OF SPECIES. 320 GENERA AM) SPKCIES. Conularia tientonensis — granulafa, — papiUata, — gracilis, Tlieca triangularis, Hall CRUSTACEA. Ulsenus arctvirus, " — crassicauda ? Wahltnberg . . — crassicauda, " — trentonensis, Emmons — latidorsata, Hall Thaleops (lUienus) ovatus, Conrad . , Asaphus ? obtusus. Hall — marginalis, " ..... extans, " nodostriatus, " latimarginata, ** ..... Isotelus canalis, Conrad — S'o''^ ■ Oekay — gigas, Hall Ogygia ? velusta, AciJaspis trentonensis, " . .. — spiniger, " ... Platynotus trentonensis, Conrad . . Ceraurus ? s^. indet pleurexanthemus. Green, — vigilans. Hall . . . — pustulosus, " . • . Calj mene mullicosta, " 2 — 3 — 4 — 1 — beckii, Green . — senaria, Conrad. ... — (sp. indet ) Phacops callicephalus, Hall — ? laticaudus, " Trinucleus concentricus, Eaton Olenus asaphoides, Emmons. . . . — unduloslriatus. Hall. . . Agnostus lobatus, " Cytlierina (sp. indet ) Plat>! and figure. li.v, 4 a-/ lix, 5 a, b lix, G a, b lix, 1 a,b Ixxxvii, I a - d iv (bis), 12 iv (bis), 13 Ix, 4 a - rf Ix, 5 Ix, fi a, 6 Ixvii, 6 a - c iv (bis), 14 iv (bis), 15 Ix, 2, 2 a Ixi, 1 a, b Ixvi, 4 a, A iv (bis), n, 18, 19 iv (bis), I'j Ix, 7; Ixi, 3, 4 ) Ixii, 1, 2; Ixiii ) Ixvi, 5 Ix, 1 Ixiv, 4 a - f Ixiv, 5 Ixiv, 1 o - e iv (bis), 20 Ixv, 1 a - m } Ixvi, \ a~ h J Ixv, 2 a - A Ixi, 2 a, b Ix, '3 Ixiv, 2 a - e 2 o- At -i 4 o - e 5 3 a - m 3 o, 6 3 a - i 3 A a- t 1 a-h 2 a-c 3 a,b 5a-f Page. 242 250 I Rocks & Groups. + + + + + + + + + 3| + Note. Several species of Graptolithus are marked a? occurriiii» in the shales of the Hudson-river croup only. These are unknown to mo ill any situniioiis, except where the strata are so much disturbed as to render it difficult to identify the Utica slate, in the absence of other fossils ; and it is quite possible that the black siate coutaining ihem is that rock. inierplicateU and folded with the green slates and shaly sandstones, which Intter, in undisturbed reg-ionsj constitute the IIud=on.river group proper. t^everal species of fossils from western localities (particularly of the genus Orthis) have been referred to (he period of the Trenton lime- 3tc>nc, though it is quite probable they may be found to range through the entire series, and to have existed a-* late as the period of the Hudson-river group of New- York : while others, peculiar to the latter, are found only near the termination of the " Blue limestone forma- tion" in western localities. [ PaLjEONTOLOGY.] 42 330 PALAEONTOLOGY OF NEW-YORK. KECAPITULATION OF THE PRECEDING TABLE, SHOWING THE NUMBEK OF SPECIES PECULIAR TO EACH FOKMATION, AND ALSO THE NUMBER COMMON TO SEVERAL FORMATIONS. CLASS OR ORDER. O w Z > CO H n RESTRICTED TO THE COMMOJV TO THE o 1 s § a- o o 2"' d 0 0 1 ■ 0 re 1 n 0" 3 3 0* 0 ■5 0 1 3 (O C , 0 0 ft> & 'J=l (/J 1 ■ 0 0 CA 3 0 3' P « w- 3 CD 1 3 re SB. (f - -" c !=■ 0 fD 3 '-J ^ s 0 3 td 1 ■f < B 0 c" 3 » c" 3 i" 0 3 re CO Q 3 c! f? ?^ 3 3 3 0 -■ 3 0. " 5 ■ 0' p p re . 3 0 3 p & r p. i 5" >^ at; 3 c I' p* ?P C c« 0 < •I CR -) 0 y PlantjE IncerTjE sedes, ZoOPHYTA .... Crinoidea Brachiopoda. . Acephala Gasteropoda . . Cephalopoda.. Crustacea ... Total 4 3 I'J S 7 12 17 11 14 U 4 .'JO 15 77 49 71 68 33 1 • 3 1 s 1 7 8 10 1 13 4 7 2 1 1 9 0 4 3 10 4 19 7 51 26 ■2S 4iJ 13 1 3 1 2 1 5 1 13 3 5 13 C 5 3 54 • • Ir - 1 1 3 3 1 1 1 1 Itl .' 3H; 4tl? Itlr 1? 1 2 f 1 95 :^-l 3 13 45 19 13 188 8 0 1 1 1 6 2 20 3 INDEX TO THE GENERA AND SPECIES DESCRIBED IN THIS VOLUME. Page, acidaspis 210 — spiniger 211 — tientonensis 240 Actinocrinus tenuiradiatus ... 18 — ? {indet.) IS Agnostus lobatus 2'>S Alecto inflata 11 Ambonychia M3 — amvirdalina IGrj — bellastriata 1 63 — cariiiata 2'J4 — obtusa 1 nil — orbicularis 1U4 • — radiata 292 — undata 1. 25 — gigas 231, 254 Leptaena alternata 102, 286 — alternistriata 109 — camerata 106 — deflecta 113 — deltoidea 106 — fasciata 20 — filitexta Ill _ — incrassata 19 — planoconvexa 114 — planumbona 112 — plicifera 19 — recta 113 — sericea 110,287 — subteiita 115 — tenuilineata, 115 — tenuistriata 108 Lingula acuminata 9 — aequalis 95 — antiqua 3 — attenuata ? 94 — crassa 98 — curta 97 — elongata 97 — obtusa 98 — prima 3 — quadrata 96, 285 — ricinilormis 95 Lituites convo'.vans 53 — undata 52 I_.YRODESMA 302 — plana' 302 — pulcliella 302 Maclurca magna 26 — matutina 10 — sordida 10 Metoptoma .' dubia 23 — ; rugoia 306 Modiola .' obtusa 40 iMODIOLOPSIS 157 — auodontoidea 298 Paob. Modiolopsis arcuatus 159 — aviculoides 161 — carinatus 161 — curta 297 — faba 158, 298 — ktus 160 — modiolaris 294 — mytiloides 157 — nasutus 159, 296 — iiuculiformis 298 — parallela 1 5S — subspatulalus 159 — ? trentonensis 161 — truncatus 29'i — (indet ) 297 Murchisonia abbreviata 3'J — ? angustata 41 — bellacincta 179 — bicincta 177 — gracilis 181, 303 — perangulata 41 — — var. A 179 — subfusiformis 180 — tricarinata 17H — uniangulata 179 — — var. abbreviata . 304 — varicosa 41 — ventricosa 41 — vittata 181 Natica? (indet.) 42 Nucula ? donaciformis 316 — levata 150 — poststriata 151 — ? poststriata 201 Ogfgia .' vetusta 227 Olenus asaphoides 256 — undulostriatus 258 ONCOCEK.iS 196 — constrictum 197 Ophileta 11 — complanata 11 — levata U Orbicula ca^lata 290 — .' crassa 290 — ? dofovniata 23 — ? lilosa 99 — lamellosa 99 — subtruncala 290 — tcrminalis 100 Ormnceras ? gracile 58 — tenuifilum 55, 222 — — var. distans .... 58 Ortliis ajquivalvis 120 INDEX OF OE.VEHA AND Sl'ECIES. 333 Paoe. Orthis bcUanv^osa 118 — eentiilintala '2S9 — costalis 20 — dichotomu 125 — disparilis 119 — ? ei-ratica 2S3 — fissicostii 121 — insculpta 125 — occi
  • tit;iIis 127 — pectinfUa 123 — — var. semiova is . 121 — perveta 120 — plicatella 122 — sinuata 1 28 — subdEiiuata .' 1 18 — subjuj^ata 129 — siibquailrata 12u — tcstiuUnaria 117 — tricenaria 121 Orthoceras amplicameratuin . . 205 — aiiellum 202 — arcuolii'utum I'JS — bilinejtuni 199 _ _ var. a 300 — clathratum 201 — fusiforme IJO — junceum 20 1 — laquealum 13 — latiannulatum 204 — moniliforme 35 — multicameratum .... -14 — primigenium 13 — rectiannulatuin 34 — recticamcratum ... 45 — strigatum 205 — subarcuatum 31 — tenuiseptum 35 — tcretiforiue 198 — textile 199 — undulosti latum 202 — vertebrale 20 1 — iindet.) .' 203 Orthonota contracta 300 — parallela 299 — pholadis 299 Paoi 1' \i..«;opiivcu.s 7 — irrogularis S — ru^osus 03 — simplex ("'3 — tubulaiis 7 — virgatua 263 — (indet.) 28 Pliacops eallicephalus 247 — ? latieaudua 24S Phytop^^is 3S — tubulosum 38 — CfUulosum 39 Platy.notus 235 — trentonensis 235 Pleurotomaria ambigua 170 — anlirjuata 31 — biangulata 31 — [?] bilix 305 — indcnta 17ij — lenticularis 172 — : nodulosa 41 — ? nucleolata 42 — .' obsoleta 44 — percaiinata 177 — (juadricarinala 43 — rotuloides 1 73 — subconica 174, 304 — subtilisti'iata 172 — tuigida 12 — umbilicata 43, 175 — {indet.) 31 Poiitos ? vetusta 71 Poteriocrinu8 alternatus S3 — gracilis 84 Raphistoma 28 — planistria 30 — — var. parva 30 — staminea 29 — striata 28 Receptaculites neptunii.' .... 08 Retepora ? foliacea 78 — gracilis 15 — incepta 15 Scalites angulatus 27 .SCHIZOCRI.NUS , 81 Pao». Schiznrrinus nodosus 81 — 8triatu3 316 — (indet.) S« SCYPHOCBI.VUS 85 — ■ hclerocostalin 85 SCOLITHUS 2 — linearis 2 SpHENOTHALLUa 201 — • angustifulius 201 — latlfolius 262 S lELUPORA 79 — antheloidea 79 Stic ropoRA 73 -^ .' acuta 74 — elegantula 75 — I'lMicstrata 10 — glomerata . . . 17 — Ubjrinthica 50 — lamosa 51 Strf.ptoplasma 17 — corniculum 69 — crassa 70 — expansa 17 — inultilamifUosa 70 — jiarvula 71 — profunda 49 Stromatocerium 48 — rugosum 43 -SUBUI-ITF.S 192 — elongata 182 Tellinomya 151 — anatinil'ormis 151 — dubia 153 — gibbosa i . . . 153 — nasuta 152 — sanguinolaroidea .... 152 Tentaculites flexuosa 92, 284 Thaleops (lllaenus) ovatus .. . 259 Theea.' triangularis % 313 TrinucleUB coiicentricus. 249, 255 Trocholites amraonius . . 192, 309 — planorbiformis 310 Turbo dilucula 12 — obscura 12 — ? cvatliiformis 72 42-2 LIST OF PLATES. • •« The numbers on the left hand indicate the figures on the plates, and ^ho^5e on the right refer to the pages containing the detaiJe-) descriptions of the several sprcinicns. Fio. Pas. Plate 1. 1 Scolithus linearis 2 2 Lingula prima 3 3 — antiqua 3 Plate 2. JO) .' e' > PalsEopliycus tubiilaris, 1 3 — irregularis 8 6 Buthotrephis antirjuata .. 8 Plate 3. 1 Euornphalus uniangulatus, 0 2 MacUirea sordida. ...... . 10 3 — matutiiia 10 4, 5 Ophileta levata 11 6 — complanafa 11 7 Turbo dilucula 12 8 Turbo ? obscura 12 9, 10 Pleurotomaria .' turgida, 12 11 Orthoceras primigenium . 13 12 — laqueatuitt 13 Plate i. 1 Retepora incepta 15 2 — gracilis l.T 3 Gorgnnia aspera Itj 4 Stictopora fenestrata lij C) — glomerata .... 17 f) Streptoplasma expansa .. 17 7 ChiKtetes (m(W.) 18 8, 9 Actinocriiiites tenuiradiutiis, 18 10 Actinocrinus ? (sp. indct.) 18 11 Asterias ?(.«;). ^n^e^) .... IS Plate 4 (bis). I. Leptena plicifera . . . 2 — iiicrassata . . 3 — fiisoiala . . .. lO 19 20 Fia Pag. Plate 1 (bis). 1 Orthis coatalis 20 5 Atrypa dubia -;... 21 6 — acutirostra 21 7 — plena 21 8 — plicifera 22 y — altilis 23 10 Orbicula? deformata ... 23 1 1 Metoptoma .' dubia 23 12 lUiEnu.'i arcturus 23 13 — orassicauda.'. . . . 24 14 Asaphus? obtusus 24 15 — marginalia .... 24 1 (3 laotelus gigas ? 25 17, 18, 19 Isotelus caualis ... 25 20 Ceraurus .' (indet.) 25 Pl.^te 5. 1 Maclurea magna . 26 Plate 5 (bis). 1 Maclurea magna 20 Plate 0. 1 .Scalites angulatu.s 27 2 Raphistoma striata 28 3 a, b — • planistria 30 3 c, (i — — var. parva, 30 4,5 — staminca 29 6 Pleurotomaria biangulata, 31 7 Murchisonia abbreviata. . 32 8 Pleurotomaria (sp indct ) 31 9 Capulus auril'ormie 31 10 llucania sulcatina 32 11 — rotundata 33 Plate 7. 1 Pleurotomaria antiquafa. . 31 '■'. Orthoceras rectiannulatum, 34 Fig. Pao Plate 7. 3 Orthoceras subarcuatum . 34 4 — bilineatum .... 35 5 — monilil'orme.. .. 35 • ; — tenuiseptum . . . . 35 Plate 8. 1 Phytopsis tubulostim . . . .3S Plate 9. 1 Phytopsis cellulosum .... 39 Pl.vte 10. 1 Modiola? obtusa 40 2 Murchisonia.' angustata . 41 3 — ventricosa 41 4 — perangulata . . 41 5 Natica?. 42 6 Pleurotomaria? nucleolata, 42 7 Murchisonia ? varicosa . . 42 8 Pleurotomaria quadricarinata,43 9 — umbilicata 43 10 — ? nodulosa 44 11 — ? obsoleta 44 \i Cytlierina (.s^i. lnrf«'^) .. . 44 Plate U. 1 Orthoceras multicamcratum, 45 Id — recticameratum, 46 Plate 12. 1 Coliimnaria alveolata . . . 47 2 Stromatocerium rugosum 4H 3, 5 Cha'tetes lycoperdoii ? . 48 4 Streptoplasma profunda. 49 6,7 Stictopora ramosa 51 8 — labyrinthica . . 50 9 Criiioid;d colum-g 51 Fio. Pao. PLA.TE 13. 1,3 Lituite3 undatus ,V3 5 — convolvaiis .... f),"! Plate 13 (bid). I Lituites undatus ,02 Pr.ATE 11. L Gonioceras ancep.s r>i Plate l.'j. 1 Ormoceras tenuifilum .. . .W Plate Hi. 1 Ormoceras tenuilihim ... 56 Plate 17. 1 Ormoceras tenuifilum ... 51 2 — — var. distans, 53 3 — ? gracile 5& 4 Endoceras suhcentralc ... 59 Pl.^te 18. 1 Endoceras longissimum .. 5i) 2 — multitubiilatum . 5U Plate 19. 1 Endoceras gemelliparum, 60 Plate 20. 1 Orthoceras fu.siforme .. .. CO Plate 21. t Buthotrephis gracilis .... G2 2 PaljEophycus rugosus .... 63 Plate 22. 1 Palseophycus simplex 63 2 Buthotrephis succulens . . 62 Plate 23. 1, 2, 3 Chstetes lycoperdon .. 61 4 — columnaris 68 Pl.^^te 24. 1 Chsetetes lycoperdon .... 66 2 — rugosus 67 3 Receptaculites neptunii ? (>8 Plate 2'). 1 Streptoplasma corniculura, C'J 2 — crassa 7U 3 — multiUmellosa. . 70 4 — parvula 71 3 Porites.' vetusta 71 6 (Genus.') cyathifoimis.. . 71 Plate 26. 1 Escharopora recta 73 2 — — var. nodosa, 73 . LIST OF PLATES. FlO. Pis. Plate 26. 3 Stictopora? acuta 74 4 — elegantula 75 5 Gorgonia pcrantiiiua .... 76 6 Aiilopora ararlinoidca ... 76 7 Alecto indata 77 8 Intricaria ? retic\ihita .... 77 9 Retepora.' foliacoa 7& 10 Stellipora antheloidea ... 7i) 11 Graptolithus ample.\icaulc, 79 Plate 27. 1 Schizocrinus nodosus... . 61 Plate 28. 1 Poteriocrinus alternatus.. 83 2 — gracilis S4 3 Scyphocrinus hcterocostalis, 85 4 Schizocrinus striatus ... . 316 Plate 29. 1 Schizocrinus.' 86 2 Bases of attachment of Crinoidea 86 3 Columns of Crinoidea ... 86 4Echino-encrinitesanatiformis,89 5 Asterias matutina 91 6 Tentaculites flexuosa ... 92 Plate 30. 1 Lingula attenuata ? 94 2 — riciniformis .... 95 3 — eequalis 95 4 — quadrata 96 5 — elongata 97 6 — curta 97 7 — obtusa 98 8 — crassa 98 9 Orbicula .' filosa 99 10 — lamcUosa 99 11 — terminalis 100 Plate 31. 1 Leptaena alternata 102 Plate 31 a. 1 Leptsena alternata 104 2 — camcrata 106 3 — deltoidea 106 4 — tcnuislriata .. . 103 PL.A.TE 31 B. 1 Leptffina alternistriata .. . 109 2 — sericea 110 3 — filitcxta Ill 4 — planumbona ... . 112 335 fi". Pao. Plate 31 b. 5 Lcptena dcflecta 113 6 — recta 113 7 — planoconvcxa .. 114 8 — tenuilineata 115 9 — subtenta 115 10 — (up. indet.) lie Plate 32. 1 Ortliis te-studinaria 117 2 — subsequata 118 3 — bellarugosa 118 4 — disparilis 119 5 — perveta 120 G — sequivalvis 12^1 7 — fissicosta 121 8 — tricenaria 121 9 — plicatella 122 10 — pectinella 123 11 — — var. semiovalis, 121 12 — insculpta 125 13 — dichotoma 125 Pl.^te 32 A. 1 Orthis subquadrata 126 2 — occidentalis .... 127 Plate 32 b. 1 Ortliis occidentalis 127 2 — sinuata 128 Plate 32 c. 1 Orthis subjugata 129 2 — sinuata 129 Plate 32 o. 1 Delthyris lynx 133 Plate 33. 1 Atrypa extans 137 2 — nucleus 135 3 — bisulcata 130 4 — deflecta 140 5 — recurvirostia .. . 140 6 — e.xigua Ill 7 — circulus 142 8,9 — ambigua 143 10 — hcmiplicata . . . . 144 11 — (sp.Jndet.) .... 145 12 — subtrigonalis . . . 145 13 — increbescens. . . . 146 11 — dentata 148 15 — modesta 141 16 — sordida 148 336 PALAEONTOLOGY OF NEW-YORK. Fio. Pag. Plate 3,'I *. 1 Atrypa ciispidata I3S 2 Ambunyclua mytiloides. . 315 3 Nucula? donacit'ormis. . . 316 4 Bucania iiitexta 317 5 Modiulopsis tenniualis .. 318 Platk 31. 1 Nucula levata 150 2 — poslstriata .... 1-51 3 'rellinoniya iiasuta lu-2 4 — sangoinolaroidea, 152 5 — gibbosa 153 0 — dubia 153 7 — anatiniformis .. 154 8 Cardiomorpha vetusta . . . 154 9 Edmondia subtruncata. . . 156 10 MfjJiolopsis ? trentonen.sis, IGl Plate 35. 1 Eilmondia ventricosa ... 155 2 — ? subangulata .... 156 3 — subtruncata .... 156 4 Modiolopsig mytiloides .. 157 5 — parallela 158 6 — faba 158 7 — nasutus 159 8 — arcuatus 159 9 — subspatulatus .. 159 10 — latus 160 11 — carinatus 160 Plate 36. 1 Modiolopsis aviculoides. . 161 2 Avicula treiitonensis . . . 161 3 — elliiTtica 163 4 Ambf nychia belhi3triata . 163 5 — oibicularis ... . 164 fl — amygdalina ... 105 7 — undata 165 8 — obtU3a 167 9 — ? 167 Pl.vte 37. 1 Holopea symmetrica .... 170 2 — obli'iua 170 3 — paluditiifonnis .. 171 4 — ventiicoaa 171 5 Pleurotomaria suhtilistriata, 17i 6 — lenticulaiis 172 7 — rotuloides 173 8 — subconica 174 Ph.tk 38. 1 Pleurotomaria umbilicata, 175 Fiii. Pag. Platz 38. 2 Pleurotomaria indenta .. . 176 3 — ambii^ua 176 4 — percarinala .... 177 5 Murchisonia bicincla . . . . 177 6 — tricariiiata 17S 7 — perangulata . . . . 17',) 8 — uniangulata . . . . 17'.i Plate 39. 1 Murchisonia bellacincta. . 179 2 — subfusiformis . . . 180 3 — vittata 181 4 — gracilis 181 5 Subulites e4onsata 182 Plate 40. 1 Carinaro|)sis carinata . ... 183 2 — palellit'ormis ... 183 3 Bellerophon bilobatus . . . 184 4,5 — — var. acutus .. . 185 6 — — var. corrugatus, 185 7 Hucania expansa 186 s — bidorsata 1S6 Platk 10 A. 1 Bucania punctifrons 187 2 Cyrtolites compressus ... ISS 3 — trentonensis. . . . 199 4 Trocholites ammonius . . . 192 Plate 41. 1 Cyrtolites trentonensis. . . 189 2 Cyrtoceras lamcUosum .. 193 3 Cyrtolites filosum 190 4, 5 Cyrtoceras aanulatum. . . 191 6,7 Oncoceras constrictum .. 197 Plate 42. 1 Cyrtoceras macrostomum, 194 2, 3 — constrictostriatum, 195 4 — multicamcratum, 195 5 — arcuatum .... 196 6 — camurum ■ 196 7 Ortlioeeras arcuoliralum . 198 8 — teretiforme 198 Plate 43. 1 Orthoceras textile 1 99 2 — bilincatum 199 3 — — var. a. . . 200 4 — clatliratum 201 5 — vertebrale 201 6 — anellum 202 7 — undulostriatum . 202 8 — (sp. indet.) 203 ~IC. Pl.*.te 44. Pas. 1 Endoceras annulatum . . . 207 Pl.vte 15. En loceras protciforme, 1 var. tenuistriatum . . 208 , 3,5 var tenuitoxlum. . . . 210 4 var. linctildtum , , . . . 211 Plate 46. Eiidoceras proteil'orme, 1 I'ar. lineolatum 212 4 fur. strangulatum . . . 212 Plate 47. Endoccras proleiforme, 1 var. tenuistriatum . . 289 4 car. lineolatum 212 3 Orthoceras junceum .... 204 Plate 48. 4 Endoceras proleiforme . . 214 2 var. tonuitcxtum.. . . 210 Plate 49. 1 Endoceras proteiforme .. 214 Plate 50. 1 Endoceras proteiforme, 214 Pl.vte 51. 1 Orthoceras amplicameratum, 205 2 P^doceras arctiventrum. . 217 3 — angusticaraeratum,218 Plate 52. Endoceras proteiforme. 1 var. elongatum 216 Plate 53. 1 Endoceras magniventrum, 218 2 — proteiforme .... 215 Plate 54. 1 Orthoceras latiannulatum, 204 2 a Endoceras approximatum, 219 2ft — magniventrum, var. a, 216 Plate 55. 1 Endoceras duplicatum .. . 219 Plate 66. 1 Ortlioceras strigatum .... 205 2 — laqueatum 2(i6 3 — — .' var. a... . 206 4 Cameroceraa trentoncnse, 221 LIST OF PLATES. 337 Fm. Pao. Pi. KTK T)?. 1 Emloceras proteil'orme . . 21iJ Pi. VTE fiS. 1 Endoceras distans 220 2 Ormoceras tcuuitilum ... 222 Plate 59. Endoceras proteiforme, 1 var. tcnuitextum. .. 217 2 var. tenuistriatum .. 217 3 var. lineolatmii . . .. 217 4 Conularia trentonensis 222 .1 — giamilata .. . .. 223 G — papillata .... . . 223 7 — gracile Plate 60. . 224 1 Ogygia ? vetusta .. 227 2 Asaphus ? extans . . . . 22S 3 Calvmene multicosta . .. 228 4 lUsenus crassicauda. . . .. 229 5 — trentonensis . .. 230 ti — latidorsata. . . .. 230 1 Isotelus gigas .. 231 PL.A.TE CI. 1 Asaphus.' nodostriatus... 248 2 Ceraurus? pustulosus . 24G 3 Isotelus gigas 233 Plate 62. 1 Isotelus gigas 233 Plate 63. 1 Isotelus gigas 234 Plate 64. 1 Platynotus trentonensis . . 235 2 Calymene beckii 237 3 — senaria 238 4 Acidaspis trentonensis . . 240 5 — spiniger 241 6 Phacops? laticaudus .... 248 Plate 65. 1 Ceraurus pleurexanthemus, 242 2 — vigilans 245 3 Phacops callicephalus . . . 247 4 Trinucleus concentricus . 249 Plate 66. 1 Ceraurus pleurexanthemus, 243 2 Calymene beckii 250 3 — (sp. indet. ) .... 253 4 Asaphus ? latimarginatus. 253 5 Isotelus gigas 254 [ PAL.SONTOLOGV.] Fio. Pas. Plate 67. 1 Trinucleus concentricus . 255 2 Olenus asaphoides 256 3 — undulostriatus . . 258 4 Calymene becUii 2.")0 5 Agnostus lobatus 2.58 6 Thaleops (lUaenus) ovatus,25'J Plate 68. 1 Sphenothallns angustil'i)lius,26l 2 — latifolius 262 3 Buthotrephis subnodosa.. 262 Plate 69. 1 Buthotrephis.' flexuosa .. 263 Plate 09 a. 1 Buthotrephis flexuosa ... 263 Plate 70. 1 Pateophycus virgatus. ... 263 2 — {sp. indtt.) 264 Plate 71. 1 , 2 Gordia marina 264 Plate 72. 1 Graptolithus pristis 265 2 — secalinus 267 Plate 73. 1 Graptolithus mucronatus. 268 2 — bicornis 268 3 — ramosus 270 4 — scalaris 271 Plate 74. 1 Graptolithus Sagittarius . . 272 2 — tenuis 272 3 — sextans 273 4 — furcalus 273 5 — serratulus 274 6 — gracilis 274 7 — livis 274 S — arundinaceus. Plate 75. 1 Favistella stellata 275 2 Chvetetes lycoperdon .... 276 3 Discophyllum peltatum .. 277 4 {Indeterminate) 277 Pl.vte 76. 1 Heterocrinus heterodactylus, 279 2 — simplex 280 3 — .' gracilis 280 43 Fio. Pio. Plate 77. 1 Glyptocrinus decadactylu8,2bl Plate 7S. 1 Glyptocrinus decadactylus,28l 2 Tentaculites flexuosa .... 284 Plate 79. 1 Lingula ((Uadrata 285 2 I.,eptiKna alternata 2b6 3 — sericea 287 4 Orthis testudinaria 2">8 5 — ? erratica 2>!S 5* — centrilineata 2NU ti .\trypa incrubesceus .... 2^9 7 Orbicula .' subtruncata . . 2'JO 8 — .' crassa 290 y — caelata 290 Plate SO. 1 Avicula insueta 291 2 — demissa 292 3 — ? desc|uamata .... 292 4 Ambonycliia radiata . . 292 5 — carinata 294 Plate 81. 1 Modiolopsis modiolaris .. 294 2 — iiasutus 296 3 — truncaliis 296 4 — curta 297 5 — (up. indtt.) 297 Plate 82. 1 Modiolopsis modiolaris . . 294 2 — curta 297 3 — anodontoides . . . 298 4 — faha 298 5 — .' nuculiformis ... 298 6 Orthonota pholadis 299 7 — parallcla 299 S — contracta 300 9 Cleidophorus planulatus . 3o0 10 Nucula ? poststriata 301 1 1 Lyrodcsma plana 3ij2 12 — pulchella 3o2 Plate 83. 1 Murchisonia gracilis .... 303 2 — uniangulata, car. abbreriata, 304 3 Pleurotomaria subconica . 304 4 _[!] bilix 303 5 _ (»p. indet.) 305 6 Metoptoma .' rugosa 306 338 PAI.JIONTOI.OGY OF NEW-YORK. Fm. P/ig. Plate S3. 7 Carinaropsis patelliformis, 306 8 — orbiculatus 3()6 9 Bellerophon bilobatus .. . 307 10 — cancellatus .... 307 Plate 81. 1 Cvrtolites ovnalus . . 308 hg Plate 84. fAB. 2 Trocliolites ainmonius . . . 309 3 — planorbit'ormis. , Plate S."). 310 1 Endoceras pioteifonne ?.. 311 o Orthoceras (sp. indet.) . . 311 3 — corallitenim. ... 312 Fl9. Pi«. Plate 86. 1 Orthoceras coralliferum.. 312 2 — lamellosum .... 312 2 a Ormoceras crebriseptum, 313 Plate 87. 1 Theca .' triangularis 313 2 Ormoceras crebriseptum . 313 ERRATA. Page 9, second line of first paragraph, (or '• Atrypa," read " Ortliis." 15, last line of page, tor "Afaclurea gigantea," read "Maclurea magna." 19, 7th line from bottom, for "/.. interslrialis," read "L. alternata." 20, first and last line of second paragraph, for "i. interstrialis," read "i. alternata." 26, description of plate v, for " 1," read " 1 a;" for " 1 a" read " 1 b ,■" and for " 1 b," read " 1 e." 31, under Capuhia auriformis, plate vi, for " fig. b," read "fig. 9." 49, second line from top, for " fig. 4," read " fig, 5." 64, 3d line from top, for " of which there about eighteen," read " of which there are about eighteen." 79, for "Compare Graptolites foliaeeus, Portlock, etc.," read "Compare Graptolites foliaceuf, Murchi- soN, Sil. System, pi. 26, fig. 3. 103, 16th line from the bottom, for "species," read "specimen." 104, 10th line from the top, for " lower," read " upper." 10.5, 5th line from the top, for "longer," read "larger." 108, description of fig. 4/, for " the same species," read " the same specimen." 114, description ni Lfptiena planoconvexa, fourth line, insert "rounded" between "coarse" and "radiating." 129, after the 0th line from the top, insert " Plate x.\xii c." 136, 6th line from the top, for "|," read "J." 159, for " Compare f'y/»icardi7« kosk/hs, Emmons," read " CompAie Cypricardites modiolaris, Emmons." " 3d line from the bottom, for " fig. 1 a," read " fig. 9 a." 160, 3d, 4th and.'rth lines from the bottom, for " fig. 9," read " fig. 11." 161, wnier Modwlo])sis trentonensis, for " plate .\xxv," read " plate xxxiv." 162, 10th, 12th, 13th and 14th lines, for " fig. 1," read " fig. 2." 216, for " plate Iviii," read " plate Ivii ;" and in the third lioe below, for " this," read " there." 220, for " plate Ivii," read " plate Iviii." 222, for " plate Iviii, figs. 1 a. Sec." read " plate lix, figs. 4 a, &c." 223, explanation of plate, for "fig. 1," read "fig. 4." " under Conularia granulata, for " fig. 2," read " fig 5." 223 & 224, under Conularia papillata, for " fig. 3," read " fig. 6." 224, under Conularia gracile, for " fig. 4," read " fig. 7." 237, Calymene beckii, no. of species, for "1," read "2;" and "3" for "2," in C. aenaria. 248, under Phacops? laticaudus, for " fig. 3," read " fig. 6." 284, under Tentacuiites ftexuoaa, reference page 92, for " pi. 39," read " pi. 29." 288, (oT " Orlhis? erratica," read " Orthis erratica." 289, foT " Orthis certtrilineata" read " Orthia? centrilineala." 2S9, under Orthis cetitrilineata, reference to pi. 79, for " fig. 5," read " fig. 5*." 297, under Modiolopsis (sp. indet.), the reference is to fig. 5, but some of the plates are printed " fig. 4." 312, under Orthoceras lamellosutn, for " plate Ixxxvi, fig. 2 a, b, c, d, e" read " 2 b, c, d, e." 327, under " Cephalopoda," insert " Lituacea." r 4* « i' (.£ .'sb'^ > PLATE 1. Fig. 1. 1. 1. SCOLITHUS LINEARIS. ( Pag. 2.) 1 a. A vertic;il or longituilinal view of a specimen of the rock containing these hoilieg. 1 6. A similar view of a specimen of partially altered and laminated sandstone from I'ennsylvania, the tubes somewhat flattened. I c. Weathered surface of a specimen of the altered sandstone (crystalline or granular i(narl/.)i from Adams, Massachusetts. Fig. 2. 2. 1. LiNGULA PRIMA. (Pag. 3.) Fig. 3. 3. 2. LlNGULA ANTIQUA. (Pag. 3.) .1 a. The usual form of this fossil. 3 6. A l)roader specimen, with ajiex wanting. 'I c. A very hroad somewliat rounded specinn-n, a view of the interior of the shell, the inner laminir wanting, and the concentric elevated lines showing in relief. .■3 il. An elongated specimen, somewhat compressed laterally. •'I c. An etdarged portion of 3 c. •1?^ loJIi'SSloJ.^SsSSj: SiXiS'lqJgiJ'lDBg'lg , I'l I . !■ I, AXT >■ ' « SHKI.I.S ■/■4 I ' " '^^^^Sf^*^ *<* / > > ^ h%^' • * el i i '" "^ i "^ .,iTH (IK t: Ic «.V ?_.\'nK*U ■ ;a>i . ,!;):i"?' -'.■'■)'.':i I'v .; ....;•» U i » PLATE 2. Fi". 1, :i, 4i 5. 4. 1. Pal^eophycus tubulauis. (Pag. 7.) Pig, 3, 5. 2. PALiEOPHYCUS IRREGULARIS. (Pag- 8.) Fig. 6, 6. 1. BUTHOTREPHIS ANTIQCATA. (Pag. 8.) I' I, ]ri-: 'J T7'-^^^~- / / f .t/l I --^ i; /• X'-^^ '^ *".''; "Vi^ ' >f >, ■%. \ V,. Jr- C* i W. ENOICOTT. LITH PLATE 3. J.'],, 1 8. 1. EUOMPHALUS UNIANGULATUS. I View vt llie uiiper side of a large specimen. I a- The luwer side of a sniallcr specimen, showini; the bioad iiinliilicus Fi'T. 2, a a. 9. 1- Maclukea sordida. Fi"•o'. ii.' 'fi'Tts r ^n^hi 'A 1 0 .1 .Oe .,;: .-r'-i -■•1 ■ I i 1 ,^^ ," .-.ll ,01 .■..,^_ . 1 ! «.;''< PLATE 4. Fig. 1. 18. 1. Retepora incepta. (Pag. 15.) 1 a. Specimen of the natural size. I b. An enlarged portion of the same. Fig. 2. 19. 2. Retepora gracilis. (Pag. 15.) 2 a. Natural size of the fragment. 2 b. Enlarged portion, showing the form of the fenestrules. Fig. 3. 20. 1. Gorgonia? aspeka. (Pag. 16.) 3 a. Natural size of specimen. 3 6. Portion enlarged, showing the rough surface of the coral, and the form of the fenestrules. Fig. 4. 21. 1. Stictopoea fenestrata. (P^g- 16-) 4 a. Natural size of the branches of this coral. 4 ft. A portion magnified. 4 c. A fragment of another specimen from a different locality. 4 d. Portion of the same magnified. 4 e. A part of the axis of a specimen, denuded of the outer crust, and presenting a series of concentric lines corresponding to the lines of progressive giowth. Fig. 5. 22. 2. Stictopora glomeeata. (Pag- 17.) Fig. 6 a, i. 23. 1. Steeptelasma expansa. (Pag. 17.) Fig. 7. 24. 1. Chjetetes . (Pag. IS.) 7 a, b, e.. The specimens considerably magnified. 7 d. The ends of tlie tubes magnified. Fig. 8, 9. 25. 1. AcTiNocRiNus tenuiradiatus. (Pag. IS.) Fig. 10. -2^. 2. AcTiNocRiNTTs . (Pag. IS-) F'£r- 11- 27. 1. Asterias? . (Pag. 18.) U (I Natural size. 1 1 J. IWaffnified view ©ipc.t\i ^,:i -I'li ;■,•( /■ n •. '\^,< .1 •U;- ^.■ll '•■'• .IrV ■ ^'-: ■■.Vi 1 ■:• I ..'I'-.- >"i'/ ■ ']' r'%f ■ ) .11 - 1 PLATE 4 (bis). Fig-. 1. 2S. 1. LePTJENA PLICIFERA. (Pfig- 19-) 1 a. Figure of the convex valve. 1 /(. Cast lit' convex valve, with a portion of the shell rcmaininR : cast of visceral cavities mapnifieii. Fio-. 2. 29. 2. Leptjena incrassata. (Pag- 19-) 2 a, b. Convex valves of this species. 2 e. Ventral valves. 2 d. Cast of the interior of the convex valve, and the same enlarged. Fig. 3. 30. 3. Leptj-ena fasciata. (Pag. 20.) 3 a, b. Convex valves of two individuals. 3 c. A larger specimen of the same. Fig. 4. 31. 1. Orthis costalis. (Pfig- 20.) \ a An imperfect shell, showing the radii towards the margin. 1 b. A cast allowing the visceral marking, and casts of radii near the base of the shell. 4 c. An impression of the convex valve, smaller than the other specimens. .Such impressions are abundant. Fig. 5. 32. 1. Atrypa dubia. (Pfig- 21.) Fig. 6. 33. 2. Atrypa acutirostra. (Pag- 21.) The two lower figures are of the natural size ; the upper one is enlarged. Fig. 7. 34. 3. Atrypa pleka. (Pag. 21.) 7 a. View of the ventral valve, showing the beak of the dorsal valve closely incurved over the beak of the former. 1 h. Lateral view of the same individual. 1 c. Doi-sal valve of a small specimen. I (I. Front view of a large specimen. ^ e. Dorsal valve of the same. Fig. 8. 35. 4. Atrypa plicifera. (Pag. 22.) 8 n, b. View of ventral valve, and front of same individual. '^ r, d. Ventral valve and front view of another individual. Fig. 9. 36. 5. Atrypa altilis. (Pag. 23.) II a. View of the ventral valve, showing the beak of the dorsal valve. '.i b. View of the dorsal valve, '.p r. Lateral view of the same shell. 9 d. Front view, show'ing the elevation of the mesial radii. Fig. 10. 37. 1. Orbicula? deformis. (Pag- 23.) Fig. 11. 38. I. Metoptoma? dubia. (Pag. 23.) Fig. 12. 39. 1. Ill^enus arcturus. (Pag. 23.) Fig. 13. 40. 2. Illvenus crassicauda? (Pag. 24.) Fig. 14. 41. 1. AsAPHUs? obtusus. , (Pag. 24.) Fig. l.*). 42. 2. AsAPHirs marginalis. (Pag. 24.) Fig. 16. 43. 1. Isoteuis gigas? ■ (Pag- 25.) Fig. 17, IR, 19. 44. 2. Isotelus canalis. (Pag. 25.) IS & I'J l,;iliniMi nr epislnm.! r.l .m linlilus, |ierh,i]is ol /. lunnlis. Fig. 20. l-'ii. 1. Geraurus? (Spacics uvdctrrvirned). (Pag. 25.) Fig. 21. A f'ragiTKMit of thf crust nf an unknown trilobit(>. ( I! H A c; H 1 O P O D A .V T H I I. (J H ] T K S ) "9 ^ ^ m '^^^ <3 if o ^ .^^iis # Sr.sJr^*»S Vl*ria;rfb»- Gsnt rl>i;t!tn; icro'iV'. iiiiivM'!' ; 111', ■nj; f'xif I'lif. .ib'i-! oil) .'1 •-.il) Hjnoiilr vi!-i')7ili i'.ii PLATE 5. 1. 46. 3. Macltjrea magna. (Pag. 26.) 1 a. The Upppr surface parlially deniuled of the shell, showing the striic with the smooth cast beneath. This is a perfect representation of tlic shell, except that the minute terminal volution is not shown. 1 h. Side view of a cast of the shell, showing the depressed turbinate form and flat spire. I c. View of the lower surface, somewhat worn ; showing the large umbilicus, which is partially fdled witli stony matter. I (/. A vertical section of the shell, near, but not directly through the centre of the spire ; showing several volutions, and the deep umbilicus. Such sections of the shell are not unusual in the rock, and they are generally vertical to the lines of deposition. I e. A view of the shell worn down from the lower side, as it very commonly appears upon the weathered surfaces of the rock at Chazy. ( SHELLS. ■) IM 5 /a STCYE BT P, SWIKTOK L'TD OP 0 t W t-NDICOTT, 59 3,;lmaN Jl ;. .„,,,, .i«"i)0 I'iJ'A'i .AM^i>lK PIATE 5 (*»). Fig! ^^ ^ M - — I ' ' (Pag. 36.) -3e f^nie abore, bat aoe 1». .^ .-_; . - ri SBi&ce of Ae nick -li^iMliS^'U' ^J^l ^ < fi. .: o:- kASTaOPODA - S «- ZSZCC ri/.ri ,liiMii(r;i .!i; ..'.v.. ■. 1 !• ......i7'.^ I ,..u. l,-.jl .U .-'t ;, , i:f !:.;iji/. Kj--) :■ I ,:••/■.« .h: I.I ■ iv ■fiiii^i ■<' . ■ (. ■ PLATE (). Fig-. 1 a, ft. 47. ]. SCALITES ANGULATUS. (Pag. 27.) Fig. 2. 48. 1. Rapiustoma striata. ( Pag. 28.) 2 a. An obliquely lateral view of the si)ecimeii. showing the spire, with the 3lri;i' upon the surface of the shell. •2 b. View of the spire denuded of the shell. Fig. 3. 50. 3. Rapiustoma planistria. ( Pag. 30.) 3 a. View of the spire ; the stria; Hat and broad. The ligure does not show the interruption. 3 b. View from beneath, showing the umbilicus. The height of tlie shell is not shown liere. ( See the figures at the foot of page 3U.) Fig. 3. 51. 4. Raphistoma planistria, «ar. parva. (Pag. 30.) 3 c. View of the spire. 3 d. Lateral view. 3 e. View of the aperture. Fig. 4, 5. 49. 2. Raphistoma staminea. (Pag. 29.) 5. View of the spire; the inner volutions partially denuded of the shell. 5 a. A lateral view, showing the aperture, which is distorted by crushing from above. The denuded spire is shown to rise considerably above the outer volution. The striae upon the side do not bend forward as much as in the original. Fig. 6. 52. 2. Pleukotomaria biangulata. (Pag. 31.) Fig. 7. 56. 1. MuRcnisoNiA abbreviata. (Pag- 32.) Fig. 8. 53. 3. PhEVROTomxiLiA. (Species U7idetermi/u!d). (Pag. 31.) Fig. 9 a, A. 55. 1. Capulus auriformis. (Pag. 31.) Fig. 10. 57. 1. Bucania sulcatina. (Pag. 32.) 10. Dorsal view, looking into the aperture, which is filled with stony matter, so that the form can not well be shown. The shell is denuded from a large portion of the last volution, but is well preserved on the part exhibited in the figure. 10 a. Lateral view of the fossil denuded of the shell ; the cast smooth. Fig. 11. 58. 2. Bucania rotdndata. (Pag- 33-) 11 a. Dorsal view, looking into the aperture, which is partially filled with stony matter, and broken at the sides. In this view, it presents the aspect of a Btllerophon. 11 ft. Side view ; the volutions not all visible, from the umbilicus being filled with stony matter. He. Longitudinal section, showing the form and relation of the volutions to each other ; the dotted line is the margin of tlie outer volution near the aperture. (s.^^E's asssES3iP®ny3. PI fl 0« STONE BY F. SWINTOK lITfl or 6 * W. EHDLC&Tr 53 HEEKMAN s: K -YOR « i;. .-i-'i '.II ,.;'.( 1 i ( .of: .-«4) .1/;; I / r.;'/^; IT I'Jii '.i.m.i.jwvifl' ,■' -iir.Mi., Ill . . : ■! ,|i i.-J ..,/! -; .I'nTAavirjia ?Ar-:a:)OiiTH0 .3. PLATE 7. Fig. 1. 54. 4. Pleurotomaria antiquata. (Pag. 31.) Fig. 2. 59. 3. Orthoceras rectiannulatum. (Pag. 34.) 2, A puitinn ol the fossil, noiirly two inches lung, exhibiting eight aaiiuhitions. •2 a. Trunsverse section, showing the position of the siphon. Fig. 3. 60. 4. Orthoceras subarcuathm.. (Pag- 34.) Fig. 4, 4 a. 62. 6. Orthoceras bilineatum. (Pag. 35.) Fig. 5. . 63. 7. Orthoceras moniliforme. (Pag. 35.) Fig. 6. 61. 5. Orthoceras tenuiseptum. (Pag. 35.) (S^l■i^.s■s■ assjiSS'S'S'Si'??; I' I 7 ' ORTHOfFH ATA Af *- C . / ''^**JW»^A^^,_. ilsmi'C.i'V:'*' V">" V ■ m ) fi^ / ^i: .'\ • .' *^:' ,^ » ^ ■^ i ON STONE DY I'.SWINTON LiTH or 8.* W CTOIC0TT.59 SEErMAB ST. S TORZ PLATE 8. Fig. 1. 64. 1. Phytopsis tubulosum. (Pag. 38.) 1. A I'lagmeiit of rock, showing several stems of this Ibssil, \vith their iinasloinosiii!; Inanolies. 1 a. A similar vertical section, where the stems have been divided, showing that tliej- were originally hollow. 1 i. A bulb of stony matter, embraced by the stems or rootlets of this fossil. The stems apparently jirocecd from such a bulb or root ; as the radicles converge below and diverge above, as represented in the (igure. 1 c. A horizontal section, presenting the ends of several stems, most of whicli are less than the ordinary size. The rock is discolored for some distance around these stems, as if deprived of its coloring matter by the carbonaceous character of the fossil. I d. A horizontal section of stems larger than the usual size : these stems are cellular, with ajiparent lon- gitudinal dissepiments in two of the four presented in the figure. 1 e. A horizontal or transverse section of the stems, showing a concretionary arrangement of the calcareous matter around tliem, which, on weatliering, presents the appearance here represented. PLWTS I I'LATK H ^ 1} i,.- 1 ^ /r "^k J - a w EnmcoTT LiTM, PLATE 9. Fig. 1. 65. 2. Phytopsis cELLtTLOsuM. (Pag. 39.) 1. Base or root of one of these fossils, with its diverging and slightly ascending branches. The surface, not being worn, |)resents no marks of structure. 1 a. A part of the specimen presents the longitudinal fibres, with very distant transverse fibres. 1 J. A longitudinal section, pa.ssing nearly through the centre of the stem, showing the longitudinal and trans- verse fibres. 1 c. Portion of two stems vvith the cuticle removed, showing the structure. 1 d. Oblique sections near the termination of branches, presenting stellate or cruciform cells. 1 a ( in part), presents quadrangular cells, arranged diagonally to the direction of the stems. These forms may arise from weathering, or solution of cellular partitions in forms like 1 d. f PL A ATS? I'L.VI'K a (,lt -JM'-V. (• .ii'l l,Ct .?f>I I .:«AUj,) /urAKOfOJiV?'-'! .<• .oi ":'!«?!•' ■"-' .'^1 I pj. ■ I'l ;..-ii ( PLATE 10. Fig. 1. 66. 1. MoDioLA OBTUSA. (Pag- 40.) Fig. 2 a, ft. 67. 2. Murchisonia? angustata. (Pag. 41.) Ficr. 3. 68. 3. Murchisonia ventricosa. (Pag. -H.) Fi — ^.y J' "V, ON SrONE BY F SWDJTDT/ Ti 8r-W, RHOJCDTT l.lTb. NfW/ YORK. PLATE 12. Fijr. 1. SO. 1. CoLTrMNABIA ALVEOLATA. (Pag. 47.) 1. A vertical section of a compact specimen, showing the striated walls ol' the cells. 1 a. A vertical section, showing the transverse dissepinieiils, with the vertical lamellae obliterated. 1 h. A transverse section (weathered surface), showing the radiating lamellre-. 1 c. The same enlarged. Fio-. 2. 81. 1. Stromatocerium rugosum. (Pag- 48.) 2. A specimen, natural size, showing the concentric lamination of the coral. The masses arc often several times as large as this one. ■2 a. A fragment magnified, showing less contortion of the lamina:', with some indistinct indication of vertical tubes or cells. 2 i. A small portion of a specimen of the natural size, showing the rugose or contorted direction of the lamince Fig. 3, 5. 82. 2. Ch^etetes lvcoperdon? (Pag. 48.) .3. specimen natural size. .•i. Probably the same species, very minute, occurring in some thin shaly layers at the upper part of the Eird- seye limestone, or at its junction with the Black-river limestone. Fig. 4. 83. 2. Streptelasma profunda. (Pag. 49.) 4. Lateral view of a specimen wliere the edge of the cup is worn down, shortening the entire length about one-third. 4 a. Section of a specimen near the base, showing the contortion of the lamellse at the centre : the section is slightly oblique. 4 ft. Transverse section above the base, showing the alternation of larger and smaller lamellae, which do not reach the centre. 4 c. Transverse section near the termination of the cup. I have some doubt whether this section is of the same species, the lamellae being much stronger and less in number than in the other individuals, which all occur in one specimen of the stone. 4 d. A longitudinal section, slightly obliijue to the axis, and coming out on one side of the centre below ; showing some of the lamella; vertically, and others obliquely. 4 e. An oblique section, being nearly transverse to the lower part of the fossil on one side. Fig. 6, 7. S5. 4. Stictopora ramosa. (Pag. 51.) li. A small fragment of limestone, the surface covered with pieces of the coral. 7. A small portion, showing the base ol the cells when separated from the internal axi.s. 1 a, Tlie same magnified. Fig. 8. 84. 3. Sttctopora labyrinthica. (Pag. 50.) N. Tlic weathered surface of a fragment "f the limestone, showing (lie transverse sections of this coral of the natural size, s rt, 1). Enlarged portions as .seen upon the .-ipecirneii almve, showing sections of two rows of cells rising oh- licjuely from the axis Fig. 9. Frngment of a rrinoidal column. (Pig. 51.) BiAfii iMrviiiii ,,„ ji/miD^iYn: njim^s'mM: run. ij -^^m^' a- WEND r'roTT LI ni PLATE 13. Fig. 1. 86. 1. LlTUITES UNDATUS. ( P^g- 52.) 1. Lateral view of a specimen. A part of the last volution, near tlie aperture, is broken otV. 1 a Lateral view of the cast of a smaller specimen I h. Dorsal view of the same. Fig. 2. 87. 1. LlTUITES coNvoLVANs? (Pag, 5.3.) 2. A portion of a cast, showing the septa and part of the outer chamber. 2 a. A vertical section of another individual as seen on the weathered surface of the limestone, showing the septa, which are removed from the smaller extremity by weathering. The cast is worn down below the siphuncle. which has not been observed in any specimen yet seen. Fig. 3, 86. 1. LiTTTiTEs UNDATUS. (Pag. 62.) A section apparently of this fossil, though the surface markings are not preserved. The septa are distinctly shown in a portion of the shell, and the dorsal siphon at two points a, o. )ii!L.^^iii iKK\t'isiUi ,i.nM5S;.^W''J)Kfrs ( ,,,'.■..,.■! A ) 1'! I.; ^^' // rf .';■' ■•*E' *T , ^vmiTCII L.1G. SI C.I W.'tlBK.TT !>. il i.tHAl IT ». Ib*t PLATE 13 (bis). Fig. 1. 86. 1. LiTUlTES TTNDATUS. ( P^g. 52.) A large specimen, showing a part of the fossil denuded of the shell, the direction and distance of the septa, and a portion of the deep outer chamber ; the extremity being brol^en off. k ! s a ii'S s Hi 2 ■\y n IE aicjs'Ji IS s '31' ^0) >••.' i Si . ( 1. 1 T U * C 1 * ) J ^m i. r'" ■■.-• ' R T H O )' t' n A T A OH STONl By F SwniTON LITII Cr C- i .V iSriCOT: 5? BEUKMaf. ST M VCRI irTinv^T -/■ 3!tMoirH' I ( ''^ PLATE 16. Fig. 1. 89. 1. Ormoceras tenuifilum. (Pag. 55.) 1. A transverse section, showing the edge of an annulation of tlie siphon, and tlie proportionate size of this part of the fossil. ( By a mistake of the artist, tlie upper edge of this ring is far too nearly central to he true.) 1 a. An artificial longitudinal section of a portion of fig. 1, pi. 1.5, showing the siphon and septa. 1 b. A longitudinal section in a direction from the ventral to the dorsal side, showing very clearly the position of the siphuncle. The specimen appears contracted at both extremities, which is due to its having been slightly bent ; so that in wearing down, the two extremities are worn beyond the centre ; while the middle portion is central, showing the siphuncle almost in contact with the external shell. 1 c. A longitudinal section similar to the last, but the shell not bent : the direction of the section is nearly in the ventral and dorsal lines. Septa and outer shell showing double lamins. 1 d. A longitudinal section, showing the siphuncle apparently central, which is due to a wearing down from the ventral side, and consequently leaving the siphon equidistant from the two lateral margins of the shell. ) e. A similar section to the last, both of which exhibit more or less distinctly the double lamintc of the outer shell and septa. In figures 1 4, c, e, the double laminae of the outer shell and septa are not so clearly distinguishable, the interspaces in the fossil being filled up by calcareous matter, so that both shell and septa appe;u- thickened. In 1 n and 1 rf, particularly the latter, the double lamina> of the septa are q\iite distinctly preserved, the interspaces being empty. sa^(5ns ffi.Jl:■^rsIE &sw.wsmis^s . n iG. OM BTijME 3V F. SWINTON , LITH OF ff&W. KJ.-DlCOTf 59 bF.EKM.-v: ST. UtW YGh ( ■( ) ,1. .■!; i; Iirj ,:). . .1 Ti ';il'.*'i ■, •, .ii r= ■'■■ ;.;,; ,,-i;,liu'i,v PLATE 17. Fig. 1. 89. 1. Ormoceras tentjifilum. (Pag. 55.) 1. A fragment of this species, sliovving the siphon directly in contact with the ventral side of the shell, a portion of which remains on the lower part of the specimen. There is also a slight irreguhuity in the size of the annuUtions, which is a common occurrence. 1 a. Transverse section of the last, showing tlie wrinkled inner surface of the siphon at the points of contrac- tion. 1 6. A longitudinal section passing through the siphuncle. The interior is here fdled with stony matter ; but in other specimens, the inner surface of the t\ibe presents the same wrinkled appearance along the con- tracted portions as is represented in 1 n. Fig. 2. 90. 2. Ormoceras tenuifilumI var. distans. (Pag. 58.) Fig. 3. 91. 3. Ormoceras? rracile. (Pag. 58.) Fig. 4. 92. 1. Endoceras subcentrau.. ( Pag. 59.) m^.s,(sm. ms-wmm. ajrsaassoKrn, * / Oin llix KIIATA 1 <: t I'l r '%- V ^ V-".'^:i?iiW^'7 I -J r > \, ■^i^ft J '^. 'i y WMi :> I \ i I^'.'H or O.J. W.SNDICOTr 59 BEEKMAN ST. NEW YORK , PLATE 18. Fig. ], ] «. 93. 2. Enboceras LONGissiBiiriM. (Pao. .59.1 Fig. 2 a, I). 94. 3. Endoceras MiTLTiTiiBni.ATTrM. ( Pasf. •')9.) isa^i^eis; iiir^i^m. )utwim''iS®'S!i& . PI in I i; / IHM f OBTKOCKRATA r .V l/y ^s^ > ON STQHE BV p. swmvojM I^a.OP G.a-W, ENI>:C0TT S9BEEKIAAN 5T. N PLATE 19. Fig. 1. 95. 4. Endoceras gemelliparttm. (P^g- 60.) 1 a. External view of the fragment. 1 b. Transverse section of the smaller extremity, showing llie siphuncle tube wliich joins the external margin ; within which are shown sections of the two embryo tubes. 1 c. Longitudinal section of the specimen, d and c being the two enclosed t\ibes, one of them iiartially covered with stony matter. lBE).jSi.©BS. m.'iL-^mm. E.SSfflSS'tfESJIg. ri I '.I ON STC(^E BY F SWINTUN. IITK.OF 0 «• W. ENDICOTT. 19 BrlKKUAN ST. NF.Vf YDHK . [■[ f.tct.a*/!: iiJlTiwJif -rH :3H '■■"'T;: I ■■:■•} (.;: '.■:^07)'r|i PLATE 21. Fig. 1. 97. 2. Btithotrephis gracilis. (Pag. 62.) Fig. 2. 99. 3. PALJEOPHycxrs rtjgosus. (Pag. 63.) Fig. 3. An undelermined species of Pal;eophycus. >? lyriU s!.\^!^C(DJ5tJr ItlOiiC) !^ ^1 W(nM) si o 1*1 :?l ri. ,\\' r.s. '« .^MMK BY t SV, il. r. 11 I.ITH OF U » W F,:ini':(j- • « YORK ..; ,7, I'i "i ■ .1 :.m PLATE 22. Fig. 1. 100. 4. Paljeophycus simplex. (Pag- 63.) 1 «. A portion of a large stem, and section. 1 6. A fragment compressed and bent. 1 c. Section of the same. 1 d. A small fragment, showing the groove along the side of the stem. Fig. 2. 98. 3. BnxHOTREPHis sttcculens. (P^g- 62.) 2 o. A portion of a large specimen, the branches scarcely compressed. 2 b. A single stem with branches, from another plant. 'm ijoii)^?!''?!:' (MW ? f'. .' ( » >: ' ^ -'o"^ "ii i^(n"»)-:^'' ' i-;: n / ^ ' k id S a "^^^^W-- > il -v' ON STONE BT r 3WINIUN. LITB- OP (; a W, i;NDICOTT H. YORK. PLATE 23. Fig. 1, 2, 3. 101. 2. Ch^tetes lycoperdon. (Pag. 64.) 1. Portion of a vertical section of a hemispherical form of large size, showing the radiating structure from increase of tubus by subdivision, and also the increase by development of marginal tubes. The tubes are filled, and have become solid columns, which are easily separable by a slight blow of the hammer. 1 a. A portion magnified, showing only the enlarged columns ; the diaphragms not visible. 1 b. Transverse section of a small conical or hemispheric form, showing the radiating arrangement of the tubes. 1 c. A portion of the same enlarged, shovfing the diaphragms at regular intervals in some of the tubes which are divided longitudinally. 1 d, e,f. Different external forms of the coral : 1 d and /, with more depressed forms, being the more usual ; while 1 e shows a tendency to branching, which, if continued, would produce a coral with a massive centre and numerous branches. I ^. A large irregular mass with numerous diverging branches, some of which are broken ofi', showing the radiating arrangement of the tubes from, a central axis. This specimen exhibits the same tendency as in 1. e, carried forward to a greater extent, showing how the same form may produce the ramose varieties. 1 h. A fragment from a larger mass, where the tubes are not filled .with calcareous matter, showing the re- gularity of the diaphragms, which are distant a little less than the width of the tubes. 1 j. The same enlarged. The mass is light and spongy like recent coral, and appears to he composed of nu- merous smaller ones which were drifted together, and afterwards recommenced their growth, forming a very irregular mass. 2. var. ramostis. A fragment of limestone, with numerous worn fragments of a coral upon its surface. The structure of this coral is apparently identical with those just noticed, though it has assumed a perfectly ramose form. 2 a. A fragment enlarged, showii\g the columnar structure upon the worn surface. The ti»bes terminate at un- equal heights, from having been worn and broken off in this manner. 3. A cylindrical specimen having the bases of three branches above, which appear to have been suddenly contracted and discontinued ; as also the central shaft, which has been broken off, and partially healed before the death of the animal. The form of the openings of the tube is not correctly given in this figure. It is not unusual, in the branching forms, to find specimens in which the branches have been broken off; and the polyps adjoining the fracture, by the addition of lateral tubes, commence covering up the part, and terminate it abruptly, as the branches of this specimen and the upper branches of 1 g. Fig. 4. 103. 4. ChjEtetes colttmnaris. (Pag. 68.) 4. A fragment of the natural size. 4 a An enlarged portion, showing the general form of the tubes. T MINION JJM'KS 7 mi (tOHAiS) '." J ■■>v. *r- '"T^r^-. // i'M ^^. 's/ iTJ^ V»'i '^iHHift^ //7 • ■- a W ENOICOTT LITH 1 PLATE 24. Fig. 1. 101. 2. Ch^tetes lycopekdon. (Pag. 64.) 1 a. Section of a small hemispliericul mass, showing the tubes nearly vertical to the base. 1 4. A portion of the same magnified. 1 c. The base of one of the hemispherical forms, where the polyps have just commenced their operations ; the tubes, though distinctly formed, have scarcely a i)erceptible elevation. The polyps here commenced their operations by attaching themselves to a valve of the Orthis testndinaria, and thence extended laterally on all sides. 1 d. A small membranous envelope of this coral, from which, in some parts, the tubes have just commenced rising : this substance is thin, and concentrically wrinkled on both sides. 1 c. A portion of an irregular massive specimen, showing a tendency to branching more distinctly than the specimens represented on Plate 23. 1/. A few tubes of the same enlarged, showing the structure before exhibited in the hemispheric masses. 1 g. A cylindrical branched specimen. 1 A. A portion enlarged, showing the radiated tubes. 1 i. Enlarged ends of the tubes on the surface of 1 g. 1 »i & 1 k. Smaller branched and cylindrical specimens. In these the direction of the tubes is more nearly in the direction of the axis of the coral, as shown in 1 o : they are, otherwise, similar to the previously noticed forms. The opening of the tubes upon the surface being likewise more oblique to the axis, they present a different form as represented in 1 ti. Fig. 2. 102. 3. Ch^etetes rugosus. (Pag. 67.) 'i a. The specimen of the natural size. 2 b. An enlarged portion, showing the form of the tubes and the rugose interior. Fig. 3. 104. 1. Receptaculites neptunii? (Pag. 68.) 3 a. The upper surface of the specimen, showing the quadrangular or rhomboidal openings upon the outside. 3 4. A portion of the same enlarged, with a few of the openings, showing the aperture of the cylindrical tube within. The opening above is not entirely circular. 3 c. Vertical section of the cylindrical tubes through the centre of the mass, as they appear on a weathered surface. As these converge towards the base, the ends only are seen as shown in the figure. 3 d. Three of these tubes enlarged, showing a contraction or stricture near their upper termination, and the same below. >ic]fisi.e©i:ins.. I o 09 A r. SI w- il '^_ PLATE 25. Fig. 1. 105. 3. Streptelasma corniculum. (Pag. 69.) 1 a. A small nearly perlecl individual. 1 b. A largev specimen. 1 c. A slioi-t and less curved specimen, with the surface distinctly marked. 1 (/. A portion of the surface of the last enlarged. Fig. 2. 106. 4. Streptelasma crassa. (Pag. 70.) 2 a. Lateral view of a specimen, the edges somewhat broken. 2 b. Longitudinal section, showing the internal arrangement of the lamellae. 2 c. View of the c\ip, showing imperfectly the meeting of the lamellEB in the centre. Fig. 3. 107. 5. Streptelasma multilamellosa. (Pag. 70.) .3 a. Lateral view of a specimen, somewhat shortened from wearing otT of the smaller extremity. 3 b. Transverse section, showing the thin lamellse. 3 c. An enlarged portion of the^ denuded outer surface. Fig. 4. 108. 6. Streptelasma parvula. (P=>g- 71.) 4 (i. The lower part of a specimen of ordinary size, with the margin of the cup broken off, showing the lamellae within. ■1 b. Tran.sverse section of the same, showing the simple radiating lainelltp. I c A group of the same. Three of the specimens lie upon the surface of tlic stone, wifli llicir bases nearly in contact. Fig. 5. 109. 1. Porites? vetusta. (Pag. 71.) !> a. Surface of the specimen, a part only showing the cells. 5 b. A portion magnified. The figure on the right hand is one of the cells more distinctly enlarged. Fig. 6. 110. 1. CY ATTnvonuis {GeTtustrndetermined). (Pag. 72.) (i a. View of .specimen, looking upon the upper or inner surface. 0 b. Lateral view, li r. lOnlarged portion of the inner surface, showing the structiu'e and arrangement of the cells. Tj'agsg'ffOJsr assass'^ffflBSffi. I'l '•: I t'OKAI-SI ^ /' : I. r /. / d iiii: 4 b. (f c. : n 6 S prvftuvda f Bla cJc Rii-er Lunestone. .? c .} A. 2 r. 4 a ■S 4 C. C /!C. ON STDNE BY f. SWINTON. G. ft W- [NOICOT- L^M. N. TOR--- PLATE -26. Fig. 1. 111. 1. ESCHAROPORA RECTA. (Pag- 73.) 1 a. Sjicciiiien iialural size ; the lower extremity expanding to lunu tlie mutlilve piutesses, and terminating abrn|)tl\ abn\e. 1 li. An enlarged portion, showing the arrangement of cells, which arc api)arently in ascending spiral lines around llie axis. 1 c. A small specimen, entirely cylindrical, tapering above to an acute point. 1 (/. An enlarged portion, showing the oblique elevated lines crossing the surface, in the spaces between which are the openings oi' tlie cellules. These lines are partially obliterated in worn specimens. 1 c. The root or attaching part of this coral : the branches embrace a portion of stuny matter. Upon the base of the broken shaft of the coral, a portion of the surface is marked as the specimen 1 a. 1 g. A longitudinal section of one of these corals, a little on one side of the centre, showing a few ranges of the apertures of the cells, and the diverging and ascending tubes on either side. Fig. 2. 112. 2. EscHAROPORA RECTA, var. NODOSA. (Pag. 73.) Fig. 3. 113. 5. Stictopora? acuta. (Pag. 74.) J (I. A small fragment of limestone, with several branches of the coral upon its surface, o b. An enlarged portion of one of the branches. 3 c. Transverse section of two branches of the coral, just above the bifurcation. Fig. 4. 114. 6. Stictopora elegantula. Fig. 75.) 4 fl. A small fragment of the natural size, showing the form of branches and arrangement of cells. 4 i. A small part of the same enlarged. The form of the cells is more rounded than appears in this figure. 4 c. The entire specimen 4 a enlarged, to show more distinctly the arrangement of the cells, the striated margin, etc. 4 d. A small specimen, bifurcating above, with the celluliferous crust nearly removed, a few of the cells only remaining near the base. The longitudinal and concentrically transverse striae are clearly shown. 4 e. A small portion of the same enlarged. 4 ./'. A more elongated specimen ; the branches narrow, and bifurcating more nearly like the last species. The celluliferous crust is removed, leaving tl^.e central striated axis. 4 g. A small portion of the last enlarged. Fig. 5. 115. 2. Gorgonia? peeantiqua. (Pag. 76.) ') a. The specimen, natural size. 5 4. A portion of a branch enlarged, showing the openings upon the two sides of the axis. ,% This species proves, on farther examination, not to be a Gorgonia. Fig. 6. 116. 1. AuLopoRA arachnoidea. (Pag- 76.) li a. The dorsal valve ui DeUhyris iyii.r, having the inner side of the shell spread over witli a fine web of this little coral. 0 4. A magnified portion, sliowing the form of the cells, openings, etc. (i c. Two of the cells still farther magnified. Fig. 7. 117. 1. Alecto inflata. ( Pag. 77.) 7 a. Dorsal valve of Lfpttena alternata^ on tiie outer surface of which this coral is affixed. 7 b. Two of tlie tubes magnified, to show their form. Fig. 8. 118. 1. Intricaria? reticulata. (Pag. 77.) 8 a. A small fragment of the rock covered by this coral, and fragments of one or two other species (nat. size). S 4. A portion magnified, showing the apertures of the cells, and the mode of branching and anastomosing. A small fragment of another coral lies across the specimen. 8 c. A small portion of a branch still more enlarged, showing the apertures of the cells. Fig. 9. 119. 3. Retepora? foliacea. (Pag. 88.) '.I a. The specimen (nat. size), upon the surface of limestone. 'J 4. Surface of the same enlarged. Fig. 10. 120. 1. Stellipora antheloidea. (Pag- 79.) II) a. Fragment, exhibiting the prominent star-form cells of the natural size. 10 4. Three of these stars enlarged, showing points or pores upon their upper surface. One of these stars has a slightly irregular form in the centre, as if composed of parts (jf two : this is true of several others. Fig. 11. 121. 1. Graptolithus amplexicaule. (Pag- 79.) 11 a. A group of these fossils ; all the stipes, except one, having been broken off by a fracture of the stone. 116. An enlarged portion, showing the edges of the sheathing scales. ^r la IB K? IT ® KJ ILIISitIES'ir'n))B'r]Se [ r II I( * (, -i ] I'l •-1). PLATE 27. Ficr. 1. 122. 1. SCHIZOCRINUS NODOSUS. ( P^g- S^-) 1 a. A nearly perfect individual of this species, with portions of the fingers and several inches of the rnhinin attached. The body is composed of plates arranged as follows : 1 6. E. Pelvis, composed of five small pentagonal plates. — . First costal plates five, heptagonal, resting upon the upper and inner edges of the pelvic plates. a — . Second costal plates five, hexagonal, resting upon the upper edges of the first costal plates. d H. Scapulars five, hexagonal, and resting directly upon the last. G. Intercostal plate. I. Double interscapular plates. The intercostal plate supports upon its upper lateral edges a pair of interscapular plates, which are in turn succeeded by two other pairs of similar plates ; the last pair truncated on their upper angles, and more deeply excavated between, supporting on the upper and inner lateral edges a small quadrangular plate, and upon tlie truncated upper edges a pair of larger quadrangular plates. K. Brachial plates. Each of the scapulars is surmounted hy a liexagonal brachial or arm-plate, wliicli supports a double cuneiform arm-joint — , from which proceed the liands and fingers m, n. 1 c. Part of one of the tentaculated fingers of this species : the tentacula are long, and not jointed ; the joints of the fingers are cuneiform, the tentacula being attached to the broatj^r side of each joint. I d. A part of one of the fingers magnified, showing the tetacula attached to the broader side of the plate. 1 «. A fragment of a small column. If. The same enlarged, showing characters precisely similar to the fragments of larger columns. 1 ff. A column of large size ; the upper part showing the larger thick plates, which are nodulose on their margins, alternating with three thinner plates : lower down the number of intermediate plates becomes four, and below this five, when the central one becomes thicker and broader, the edges projecting beyond the others. 1 A. A fragment of a small column ; the surface worn nearly smooth, and presenting only the points of at- tachment of the side-arms on the thicker joints. 1 t. A small column ; the larger joints unusually projecting, and their edges elevated. 1 k, I, m. Fragments of columns from difTerent parts, showing the alternation of larger and smaller plates, the points of attachment for side-arms, and the weathered surface exhibiting the serrated appearance of the edges of the plates. 1 n, 0. Specimens showing the character and aspect of fragments of diflferent parts of the column. In some portions there are six, seven, and eight intermediate plates; the central ones usually extending a little beyond the others, and showing a nodulose margin. 1 p. Ends of the plates of the columns, showing a striated surface. 1 p *. The same enlarged. WlSUISfll'^JJf ILHjS«lKS'lC'©Sf:ifi. I'l ,'7 'p ( rillXdlDKA I 'X'^ \^ / M^ E;>^>;ea t^J IV-ijir ■-naT.I; -. I J. ..{■ -.-■'., ,!if, 'Cr.iJ.'M . ^'!j .1 . ■''•'j'".li-!- ;■ . I ii',' .;f ■."' '■■j'.'^s o-.i PLATE 28. Fig. 1. 123. 1. PoTEniocKiNus alternatus. (Pag. 83.) 1 a. A specimen upon the weathered surface of the limestone, showing imperfectly the structure and arrange- ment of tlie plates, with the tentacula and a portion of the column below. 1 b. Shows the arrangement of the plates around the column, and the attachment of the fingers to the upper part of the brachial plate. 1 c. A brachial plate separated. 1 d. A costal plate separated. 1 e. A pelvic plate. 1 /. A portion of the column of this species, showing the alternating width and rounded edges of the plates. Fig. 2. 124. 2. PoTEKIOCRINTTS GRACILIS. (P^g. 84.) 2 a. A specimeh of the natural size, broken off just below the last joint of the column, which adheres closely to the pelvis. The tentacula are broken off above, before reaching their termination. '2 b. The same enlarged, showin*:; more clearly the arrangement of the plates, arid the situation of the inter- costal plate. E. Pelvis. F. Costal plates. J. Irregular intercostal plate. H. Scapular plate. 2 c. The body of another specimen, vyith a few of the last joints of the column attached. 2 d. The same enlarged, showing the intercostal plate and the structure of the column. Fig. 3. 125. 1. ScYPHocRiNus HETEROcosTALis. (Pag. 85.) 3 a. A specimen (natural size), with the fingers and column broken oflT; tlie form otherwise well preserved. 3 b. The structure and arrangement of the plates, the letters indicating the parts as explained in the previous figures. The plates are slightly enlarged beyond their natural size. 3 c. The base of the specimen magnified, to show the fimbriated plate adhering to the base of the pelvis. 3 d. Lateral view of a smaller specimen of the same species, with portions of the fingers remaining. 3 e. The same, showing the base, with a fragment of the column broken off and lying at the side. 3f. A portion of this column magnified, to show the character of the plates. Fig. 4. 378. 2. Schizockinus steiatus. (Pag- 316.) 'I a. The body of this species, with a small part of the cohimn attached. 1 h. A portion of the column enlarged. 4 (*. An eidarged figure, showing the structtu'e and arrangement of the plates. ^^iajS2ir'5i''®S!r aassas'u'.oiiYis! , I'l '2li ( cniXOID K A ) '0- 1^- ri \ 0 ^Z" 0 \ u> 'n o 0. U i V/-i:"Oa~t. PLATE 29. Fig. 1. 126. 2. ScHizocKiNus? (Pag. 86.) Fig. 2 a, b. Bases of attachiuetil of CKiNoiDiiA. ' (Pag. 86.) Fig. 3 a, h, c. Columns of Ckinoiuea. ( Pag. 86.) Fig. 4. 127. 1. ECHINO-ENCIUNITES ANATIFORMIS. ( P^g. 89.) ■1 a. The column, with a single detached plate near its upper termination. The long narrow joints of the co- lumn, which gradually become shorter and broader until they form broad thin rings in the upper part, are clearly shown. The plate belongs to the second range, and is hexagonal, with three prominent ridges upon its surface. A curved depression on one side shows that it formed a part of the lateral aperture. 4 b. Part of a similar column, with the plates of a crushed cup lying at its upper termination. There are, at the summit of this specimen, one or two free nearly circular discs, and one apparently attached, as if forming the base of the tentacula at one point. 4 c. One of these plates enlarged. The surface is worn smooth, with the exception of the ridges on the plate. 4 d. A larger and more perfect specimen ; the plates near the base showing the strong slriie upon their sur- face, which are at right angles to the edges. 4 c. The structure, as far as can be ascertained from our specimens. 4 / Tlie surface ol' one of the plates, magnified, to show the striae. Fig. 5. 128. 2. AsTERiAS matutina. (Pag. 91.) 5 a. The specimen, natural size. 5 b. A portion enlarged, showing the form of the plates and the punctate surface. Fig. 6. 129. 1. Tentaculites? flexuosa. (Pag- 92.) 0 a. A single specimen of this species, with a portion of the same magnified, showing tlie transverse septa, ti i. A group of the same species, adhering by their smaller extremities to the dorsal valve of Ortliis tesludi- naria. At c, there is the base of several cells of the Chtetetes lycoperdon, adhering to the same sliell. IJ d. A single tube magnified, showing more distinctly the striae upon the surface, and, also, in some degree, the irregularity of the annulations. '•^)Km aT'-j: 0 XT jl 'i ^.OR ^. ?£' x:* \Ti^ . J* I .".» ( cm X n\ II K A I ^^i> I *p:j''V:: o ? ^ KM ^ ^'> ^ \ \ ^^:^ ^i / 3 •T-t*" '^r.I a; yfi ■=) i-ur-* '.t '1) - •; II l> 111 ■- '.'.,1 I •Hi. ; b-:.' .H(j yi.'!;, ; I A l«ir»ti .."i)(1jii;i"ip ■ ■{.^ .001 ,>ji^) ,! ■•. I. • 1 i J .• - HI. .i # PLATE 30. Fig. 1. 130. 4. LiNGULA ATTENUATA? (Pag. 94.) I (I, IS the largest individual ol' this species yet seen. 1 b. A specimen ol the oidinarv size. Fig. 2 a, b, C. 131. 5. LiNGULA RICINIFORMIS. (Pag. 95.) Fig. 3 a, A. 132. 6. Lingula jeq.uai,is {a variety of the /ast species?). (Pag. 95.) Fig. 4. 133. 7. Lingula quadrata. (Pag- 96.) 4 a. A specimen of the ordinary size ; the shell partially e.xlbliated, and presenting the strong radiating striae along the centre. 4 b. View of the edge of the shell, with the two valves clo.sed. It appears slightly inequivalve from compression. 4 c. A specimen of larger dimensions, from which the shell is partially exfoliated. Fig. 5. 134. 8. LiNGULA elongata. (Pag- 97.) Fig. 6. 135. 9. LiNGULA curta. (Pag. 97.) fi a. Specimen from the Utica slate. 6 b. Specimen from the Trenton limestone. Fig. 7. 136. 10. LiNGULA obtusa. (Pag. 98.) 7 a. A very perfect specimen of large size, giving the e.xact form of the shell : radiating striiE scarcely visible. 7 b. Another specimen, the form not quite so perfect as the last, but the radiating striae more distinctly visible. 7 e. A smaller individual of the same species. Fig. 8. 137. 11. LiNGULA ceassa. (Pag. 98.) 8 a, b. View of both valves of this species. 5 c. View of the edge of both valves, closed ; one being more convex than the other, and slightly arched. S d. A larger specimen, somewliat crushed. S e. A smaller specimen. Fig. 9. 138. 2. Orbicula? FiLosA. (Pag. 99.) y a. A young shell, very convex or obtusely conical in form. 9 b. A larger shell, less convex than the last : this portion is magnified. 9 e & d. Two apparently full grown shells of this species; the form is much depressed, nearly flat, and the surface completely covered by fine striae. Fig. 10. 139. 3. Okbicula lamellosa. (Pag. 99.) 10 a. Ventr.d view. lu *. Lateral view. Fig. 11. 140. 4. Orbicula terminalis. (Pag- 100.) 11 a. Dorsal valve, showing the central apex and lateral depression, which extends to the margin. 1 1 A. Ventral valve with marginal apex. 1 1 c. Lateral view of a perfect specimen. U d. Ventral valve, marked with strong concentric lamellae; apex marginal. %• '^i IS .'I? S" (2) iS Ei H 2£ 3^ :i JT to ij E , i la * 15 7fr 4ft I 11 It A c H I O 1' o ii A . 1 4a 8£ PI. 30. • 2a D 0 2^ 2c # • 3ff. 'Ta .36 6 a • 6J Sa 86 • 12 a IZ 'M 9h 9 ' ' /T^^eU tv- **^^v ^- il 2.^ lis Drawn Jgr Kcs-Holl . ■Tl ) r-j-o-' i-ici .:' i;ii < 'ACA ,:■■'■'] V J. -.:•! :-.li .ii.;i iii rrti PLATE 31 A. Fig. 1. 141. 4. Lept^na alteenata. (Pag. 102.) 1 a. A specimen which is contracted just below the ears and bent abruptly upwards, having towards the front several folds, and a more prominent one directly in front. 1 J. A lateral view of the same specimen, sliowing the abrupt and extreme deflection of the shell. 1 c. A specimen having the same general form as the last, but contracted and folded in front so as to present precisely the same form as the Strophomena nasuta of Conr.\d. In both the preceding specimens the beak is perforated, as is exhibited in the enlarged view of the hinge in 1 o, which at the same time shows the foramen not quite closed. Tlie nasute feature above indicated is often connected with a single elevated ridge, or more prominent stria, much larger than the others, and extending from the base to the beak of the shell. This appears very distinctly in the two preceding specimens ; but to prove that this character is common to the species, the specimen t d is represented, showing a prominent line down the centre, while the shell is totally destitute of the other characters of S. nasuta, being scarcely convex and very regularly semioval. 1 e, f, g ii, h. These figures represent a series of the younger shells of this species, as they occur in the com- pact limestone of Middleville, Little-Falls, Trenton-Falls, and other places. 1 i. A very convex specimen, much contracted below the cardinal line, with the alternating striae less distinct. Fio-. 2. 142. 5. Lept^na cabierata. (Pag. 106.) 2 a. Lateral view of tlie specimen, showing the extreme concavity of the shell in the centre, and the nearly flat disc. 2 b. Front view, showing the great deflection ; the surface is puncto-striate, from being denuded of the shell. Fig. 3. 143. 6. Lept^na deltoidea. (Pag- 106.) 3 a. A specimen showing Ijut a slight difference from the last described species. It is marked by distinct con- centiic wrinkles U]ion the disc ; is finely striated, with more prominent elevated ones alternating with every four, five or six of the smaller ones. In this respect it partalces of the characters of specimen 1 i. 3 b. A specimen presenting the same form as the last, except tliat it is more produced in front. The concentric wrinkles on the front are perhaps more distinct, and the shell is contracted more abruptly just below the extremities of tlie cardinal line, producing small acute ears. ;i c. Lateral view, showing the elevation of the shell. 3 d. A specimen of neai-ly the same form as the last. The concentric wrinkles are more distinct, and the ra- diating striae are equal, except on the central part of the shell, where they are stronger. 3 e. A larger specimen, with the disc distinctly wrinkled and marked by nearly equal radiating striie ; scai'cely produced in front. The strife on the centre are more distinct than at the sides. 3f. A very perfect specimen in form and markings, from a drawing by Mr. Conr.\d. Fig. 4. 144. 7. Lept^na tenuistriata. ( Pag. 108.) 4 a. A small specimen, the dorsal valve having about four or five strong undulations upon the surface : the cardinal extremities are strongly deflected. 4 b. Cardinal line, showing imperfectly the deltoid foramen. 4 c. A small specimen, having about six distinct undulations oh the disc, and three less distinct ones towards the beak : the shell bends abruptly upwards, nearly at right angles to the disc. 4 d. A small shell, exhibiting very indistinct undulations upon the surface, being very abruptly deflected near the margin, and extremely extended on the cardinal line. 4 e. A larger specimen, sliowing about four or five distinct undulations on the dorsal valve, and the same number on the ventral valve. The cardinal line is more extended than is usual in this species. if. Ventral valve and cardinal line of the same specimen, showing the narrow almost linear area ; the latter enlarged, exhibiting the perforation in the beak. 1 g. Lateral view of the same specimen, showing the abrupt deflection and elevation in front. ( BB.A.CHIOPODA) IM :nA 'f: % a.*- 4» / 4:f Z^ ■if Dth-wii1>7 SKE. Xi.;'iok.-ved3v ^JdvitJel/titiie ■; I . I. i 1- ■ r PLATE 31 B. Fig;. 1. 145. 8. LeptjEna alternistriata. (Pag- 109.) 1 a. Dorsal valve of a large specimen, showing a very regular alternation in the size of the striie, 1 b. Ventral valve of the same specimen, the strise being regular and uniform in size. 1 c. A smaller specimen, presenting a greater extension of the cardinal extremities, and an irregular alterna- tion of the strise upon the surface. Fig. 2. 146. 9. Lept^na sericea. (Pag- 110.) 2 a, b. The form and surface of the shell are perfectly preserved in this specimen, both valves of which have distinct larger striic alternating with several smaller ones. 2 c, d. The opposite valves of another specimen, showing the equal strise and a few' concentric lines of growth. 2 e. Interior of the ventral valve, showing two winglike papillose callosities for the visceral attachment. 'If, shows a variation from the preceding internal structure. 2 g. Interior of the convex valve, showing the visceral impression, margined by a sharp elevated ridge. 2 h. View of the cardinal area of the convex valve, showing the deltoid aperture which is partially closed. Fig. 3. 147. 10. Lept^ina filitexta. (Pag. 111.) 3 a. Ventral valve of a large specimen. 3 b. Cardiiial area. 3 c. Interior of the dorsal valve. 3 d. Dorsal valve of a smaller specimen. 3 c. Cardinal view of tlie same. 3/. An enlarged portion of the surface, showing tlie textile character. Fig. 4. 148. 11. Lept^ena plandmbona. (Pag. 112.) 4 a & i. Views of the two valves ; the ventral one b showing some strong imbricating lines of growth. •1 c. Cardinal view, showing the nearly linear area and closed foramen. ■1 (/. Interior of the concave valve. 4 c. Lateral view of the shell. Fig. 5. 149. 12. Lept.i:na deflecta. (Pag. 113.) 5 a Dorsal valve of the specimen. Ti b. Cardinal area of the same. Fig. 6. 150. 13. Left, ena recta. (Pag. 113.) t'l a. View uf the ventral valve. ' •) b. Cardinal view of the same shell. Fig. 7. 151. 14. Lept^na planoconvexa. (Pag. 114.) 1 a. View of the dorsal valve, with one of the cardinal extremities produced beyond the other. 7 6. A smaller specimen. 7 c. Profile view of the shell. 7 d. Cardinal view of the first specimen. Fig. 8. 152. 15. Lept^na tenuilineata. (Pag- 115.) Fig. 9. 153. 16. LEPT.a;NA subtenta. (Pag- 115.) ;• a. View of the dorsal valve, i) J. Interior of the hinge margin. Fig. 10. 154. 17. Luns.'eiA {Species U7idetermined). (Pag- 116.) 10 a. Ventral valve, showing the equal radiating stris. 10 ft. Dorsal valve, with unequal striae. 10 e. Cardinal area, and the same enlarged, showing the open foramen and imperforate beak. ^r'n;i:^j:^<'t''DVT -rj^xiiaaa'DSfia ( Hit.VClI lO UO IJ A I \ - . .^s^—^ ¥^" ^»vk« Hv ^>> f r ) .f .•J J %m . L«i*=V Wr».BT'^vle Tirii!-' ii)'- )T ),M Ji ■ ! s^'ir: U'.> A .(ti' i .11 ■ ,1 ■I ■)': 'ii.V,; .ri- .„■.!, . :,: '; i ■ ■ ■ ,,•■,,, |- ,,,, , , .;:' '0 •"." J.:l/'- '■' \\ ■■'-'] .(V-iiii;i .,. :)■■■■ !■ • •>:'^,l •■1.1..IH ,».'l ,M,Mi I..-. .,, viill-..i..-ul '..it ;^lic/f...<.- ..-^ftll.. PLATE 32. F)V. 1. 155. 2. Orthis testcdinaria. (Pag. 117.) 1 II. Ventral valve. 1 I'. Profile view of the shell. 1 c. Dorsal valve. 1 d. Canlinal view of shell. 1 c. A smaller specimen. 1 /. Interior of the dorsal valve. 1 g. Interior of the venti-al valve. 1 h. Cast of the dorsal valve. 1 i, /•% I- The same species from the Blue limestone of Ohio. Pier. 2. 156. 3. Orthis stib.«:(1uata. (Pag. 118.) 2 a. Ventral valve. 2 b. Dorsal valve. 2 c. Profile view. 2 d. Cai-dinal view. 2 e,f. Figures of a smaller specimen; the ventral valve being less convex than in the older specimen. pjg, 3. 157. 4. Orthis bellarugosa. (Pag. 118.) 3 a. Ventral valve. 3 ft. Dorsal valve. 3 c. Profile view. 3 d. Cardinal view. 3 e. An enlarged portion of the surface, showing the imbricating squamose lamellae. Fio-. 4. 158. 5. Orthis disparilis. (Pag. 119.) 4 a. Ventral valve. 4 6. Dorsal valve. 4 c. Profile view. 4 d. Cardinal area and foramen. Fio-. 5. 159. 6. Orthis perveta. (Pag. 120.) 5 a. Ventral valve. rj ft. Cardinal view. 5 c. Profile view. 5 d. Cardinal view magnified. Fio-. 6. 160. 7. Orthis tequivalvis. (Pag- 120.) G a. Ventral valve. 'i ft. Dorsal valve. 6 c. Cardinal view, showing the equality of the valves. Fig. 7. 161. 8. Orthis fissicosta. ^ (Pag. 121.) 7 a. Ventral valve. 7 ft. Profile view, showing the projecting beak of the doi-sal valve. Fiff. 8. 162. 9. Orthts TRICENAKIA. (Pag. 121.) S a. Ventral valve and area. 8 A. Intei-ior of the dorsal valve. 8 c. Exterior of the dorsal valve. 8 (/. Interior of the ventral valve. 8 e. Profile view of a perfect specimen. Fig. 9. 163. 10. Okthis plicatella. (Pag. 122.) U rt, ft, c. Ventral valves. 9 d. Profile view of the last. 9 c. Cardinal view of the same, fl/. Ventral valve of a large specimen. 9 g. Profile view of the same. Fig. 10. 164. 11. Orthis pectinella. (Pag. 123.) 10. A small individual. 10 a. Ventral or convex valve. 10 ft. Dorsal valve of the same specimen. 10 c. Cardinal view of another specimen. 10 d. Ventral valve. 10 e. Interior of tlie ventral valve. Fin-. 11. 165. 12. Orthis pectinella, var. semiovalis. (Pag. 124.) 11. .\ large specimen, somewhat imperfect. 11 o, ft. Dorsal and ventral valve of a smaller individual. Fig. 12. 166. 13. Orthis insculpta. (Pag. 125.) 12 a. Dorsal valvl^ thi' beak imperfect. 12 A. Interior of tlie dorsal valve. 12 c Dorsal area. Fig. 13. 167. 14. Orthis dichotoma. (Pag. 125.) 13 «. \'entral valve, showing the projecting dorsal beak. 13 ft. Profih' view of the sami'. TT US B E5 B" © H IL It M IS 3 ffi © W :S , H K A r: H I n p o 0 4 1 PI. yi. I 9l Ba •ia 2« in, d J ff*. I 2y 5d ""%- dh 5^ 4^ 'Sri ♦ ■«: PLATii 32 A. Fig. 1. 168. 15. . Orthis subquadrata. (Pag. IHG.) I «, 0, c. 'I'liice views of the dorsal valve, showing gradiition in the size ul the shell. 1 d, e. Profile views, showing the nearly equal elevation of the beaks. 1 /, g. Front views, showing the slight elevation produced by the sinus in the ventral valve. 1 A, i. Ventral valves, showing the slight depression along the centre of the shell. 1 k. Cardinal view, showing the area, foramen, etc. 1 /. Exterior of a large dorsal valve somewhat llattencd from compression. 1 m. Interior of the same, showing the form of the visceral impression and the marks of tlie external radii, which terminate near the margin. 1 n. Dorsal area and foramen. 1 0. Interior of the ventral valve, showing the narrow area and foramen, with the projecting medial tooth, which is enlarged in the upper figure. The impressions of the external radii are visible but a short distance from the margin on the insidi- of the shell. Fig. 2. 169. 16. Orthis occidentalis. (Pag- 127.) 2 a -f, are illustrations of a series of this species, beginning with the smallest recognized specimens, and passing through the several grades, till the increasing rotundity of the ventral valve towards the umbo rises above the beak of the dorsal valve. 2 g, h. Profile views of several specimens as above. 2 i, k, I, m. Front views, showing the increasing sinus of the dorsal valve as the shell becomes older. wjE-issfii'^ST oams^rosfs. I UK A( III Ill-DIIA I '^^i^gitm^ .\V' .# ':'4^»SP'' -'y I- -fJ' ^ V/ J %. iJrawi. kr Mi3 .: U H .11 PLATE 32 B. Fig. 1. 169. 16. Okthis occidentalis. (Pag. 127.) 1 a, b. Cardinal views of a young and old specimen of this species. 1 c. Ventral valve of an imperfect specimen, partially showing the interior of the dorsal valve, wliicli is strong- ly marked by tlie external radii. 1 d. Profile view of a large specimen. 1 e,f, g. Views of ventral valves. 1 /(, i. Interior of ventral valves, showing the medial tooth and the marlcs of the external radii. Fig. 2. 170. 17. Okthis siNCATA. (Pag. 128.) 2 a, b, c, d, e. A series of specimens, illustrating the variations produced by age. 2y, g, h. Profile views of specimens of difierent ages, showing the gradual increasing rotundity of the ventral valve, and also the more acute beak of the dorsal valve as compared to the last. '2 i, /(. Front views of young and old specimens. ^cisuRxxiemx^ it,K»nti3ir>ii)X!n«. !'l 'M II UUl AC H I OPODAl .r ■''// ^^ fc.^ >^ if?..'ji tj Dr»7m by Mis S M Ball Er.oriTt J ij J I PeMc V! '(i.';fj>^-.-'i f't'i -.11 h't; t]Vi^7 I i-'l"fi T>«'',' "K' ^(.firU ,:iv5b ->n> ,^ .ovtsiy ii-'luiiv .Of!) '•'-v'/.-jiV k i ?ih;iif'''filiu: I'i" on». "uik.v !•■ ■/ J"ii'.i>is:i .]« ,A 1) . .' T Ml ■ mi PLATE 32 C. Fig. 1. 171. 18. Oethis sttbjtjgata. (Pag. 129.) 1 a. Ventral valve of a young specimen. 1 b. Profile view of the same. 1 c. Front view of the same. 1 d. Dorsal valve of another specimen, with a deep sinus. 1 e. Front view of the same. 1 /. Dorsal valve of an older specimen, showing the gibbons ventral valve projecting beyond the cardinal line. 1 g. Front view of the same. 1 h. Dorsal valve of an old individual. 1 i. Front view of the same, showing the deep sinus of the dorsal valve, and the corresponding elevation on the opposite valve. 1 k, m. Cardinal views of young and old individuals. 1 n. View of the ventral valve. Fig. 2. 170. 17. Oethis sinttata. (Pag. 128.) 2 /, m. Cardinal views of young and old specimens. .2 n, o. Ventral valves of a young and old specimen. 2 p. Interior of the dorsal valve, showing the form of the visceral impression, and the radii near the margin. 2 q, r. The two lower figures show a slight diflierence in the character of the visceral impression. 2 s. Interior of the ventral valve, showing the medial tooth, which is thicker and stronger than in the last species, and is connected with a strong medial ridge which is trifid below. ifiiiMSf'i*©»f iL:iMiisi?if®3a":s. !'l U' 11)11 A I II I fll'OllAI > '■^■■'^j'hiiUi^ -/' ./ Ih ""^^.. w*--. 'ir»r ' ^hh. PLATE 32 I). Fig. 1. 172. 1. Delthyeis lynx. (Pag. 133.) 1 a, b, c, d. A series ol' specimens, showing the gradations in size, and the increase in number of plications as the shell becomes older. The smaller specimen 1 a has three plaits in the sinus and four on the mesial lobe, witli seven on each side, thus : 7 f 7. In 1 b, there is the partial development of a fourth plica- tion in the sinus, and a fifth on the mesial lobe, though there is no increase in the number of lateral ones. In c and d, there is a full development of the f medial plications, and 10 lateral ones. I e and /, are front views of a and d. 1 g. Profile view of d. 1 h. Ventral valve of another form, showing e.vtended beaks. Medial plications f ; lateral ones 13 on each side. 1 i. Front view of the same. 1 k, I, m, 0, q, 4, u. A series of western specimens, with the mesial and lateral plications (7 f 7 ) ; showing DO tendency to increase of either number, though the size of the shell increases as in the previous series. Figures 1 m, q and s, show the cardinal extremities more extended and acute than in the other forms ; while the specimens o and u have the cardinal extremities shorter, scarcely equalling the width of the sheU. 1 n,i>, r, t, are front views of 1 »i, o, q, u, respectively. I A, B. Cardinal and profile views of an extremely globose specimen, having the cardinal line much less tlian the widtli of the shell, and the extremities rounded : the area is broad, and very well defined. The plications are 7^7. 1 c. Dorsal valve of a specimen, having the cardinal line extended beyond the width of the shell, and ter- minating in short acute ears. 1 D. Front view of the last, showing the plications, which are 10 f 10. 1 E. Profile view of the same. 1 F. Cardinal view of another specimen, with the extremities extending beyond the greatest widtli of the shell below. 1 G & H. Front view and profile of a specimen similar in form to 1 b, but having the plications 10 ^ 10. The cardinal line is less tlian the width of the shell. 1 I, K. Front view and ventral valve of a cuboidal specimen, showing some irregularity in the development of the plications ; a single one on the sinus and two on the medial lobe being fully developed, with smaller ones on each side, while the lateral plications are six and seven. Tlic following present some deviations from the prevailing forms, and approach to tlie Spirifer denlaius ol ul Verneuil : 1 L, M, N. Ventral, dor.sal, and profile view of a small specimen, with tlie plications arranged thus : 5 ^ .5. 1 o, p, Q. Ventral, front, and profile view, having the same form and proportions a.s the last, but liaviiig an additional plication upon each side. 1 H, s, T, u. Ventral valve, front, cardinal, and profile views of the same specimen, which is remarkably extended on the hinge. This specimen has a single fully developed plication in the sinus and two on the mesial lobe, with the rudiment of another on each side of the sinns and of the mesial lobe, while the lateral plications are ten on each side. lr;f:SMTS'!t? ^SMSk^'MiSTS P I ;'. i I) BR Al'H lOPOOA c ^---^ -»-5r- ,./???^ ;/ ^1 ■^4/'^p^ ■^^ rn. Of 0 V H KNDir-OTT N * r,7 ■ .... ,* ' "(i- y... j.rtyi .(Ti .. .! ^' .1 .■ -l (.i-ii .tl .VI i 7.1 r A .it .d> b. Left valve of the same, slightly contracted behind. 0 c. A separate valve, in which the posterior contraction is scarcely perceptible. 0 d. Left valve of a specimen, in which the posterior side is much contracted. 6 e,f. Separate valve of an old shell, with a view of the dorsal margin. Fig. 7. 195. 5. Tellinomya anatiniformis. (Pag. 154.) Fig. 8. 196. 1. Cardiomorpha vetusta. (Pag- 154.) Fig. 9. 198. 2. Edmondia subtrttncata. (Pag. 156.) Fig. 10. 209. 10. MoDioLOPSis? trentonensis. (Pag. 161.) ( AI'i':PHAL A, PI 3 4. f v^ .••"A 2 h ^^k :-^ I 9 5 h .J" - *■ e ^ »■ s:D}fz fii- 3vni7o» . i.:tk. oj' r».iw. ekdicott s.vobe. PLATE 35. Fig. 1. 197. 1. Edmondia ventricosa. (Pag. 155.) 1 a. Right valve of a large and perfect specimen. 1 b. Anterior extremity of the same. 1 c. Dorsal view. 1 d. Left valve of a smaller individual. 1 e. Left valve of a specimen which has been compressed vertically. 1/. Dorsal view of the same. Fig. 2. 199. 3. Edmondia? subangulata. (Pa-g. 156.) 2 a. Left valve of this species. 2 b. Dorsal view of a single valve. Fig 3. 198. 2. Edmondia subteuncata. (Pag. 156.) 3 a, 6. Casts of this species, in the crystalline limestone at Watertown. 3 c. A cast, showing strong imbricating ridges towards the base. Fig. 4. 200. 1. MoDioLOPSis mytiloides. (Pag. 157.) ■J a. Right valve of a specimen, showing the muscular impression. 1 b. Dorsal view. Fio-. 5. 201. 2. MoDioLOPSis parallela. (Pag. 158.) Fig. 6. 202. 3. MoDioLopsis faba. (Pag- 158.) 6 a. A large and characteristic form, the muscular impression visible'at the anterior extremity. 6 6. A smaller specimen, less regularly rounded. 6 c. A specimen having a more oblique form, with the anterior lobe more compressed and extended. tj d, A young specimen, having the umbones and sinus nearly central. Fig. 7. 203. 4. MoDioLOPsis nasutus. (Pag- 159.) Fig. 8. 204. 5. MoDioLOPsis arcuatcs. (Pag. 159.) Fig. 9. 205. 6. MoDioLopsis subspatulatus. (Pag. 159.) 9 a. View of the right valve of this species. 9 b. Dorsal view of the same. Fig. 10. 206. 7. MoDioLOPSis laths. (Pag. 160.) 10 rt, b. The left valves of two specimens, showing a slight variation in form. Fig. 11. 207. 8. MoDioLOPSis cakinatus. (Pag. 160.) 11 a. A large specimen, with prominent umbones. 11 6. A smaller specimen, showing the true form of the shell more distinctly than the last. 11 c. A smaller specimen, in which the posterior margin is less oblique. 'S'a.iiBJfir.stsr %:iw-.m®''-:x'®i^':i;,o I' 1 3.; ACEPHALA f.V ■JiS-iiiL-^-:' : .■' \ ¥-1 % '4 i I, 5,«eiSi,. ^ no 3 I mj OK- ^sjoNE av r .*wi»,Toy , .-n-r : M f- »•■ 'll :.i.i^ ' '•] ■ <': :-i:'i 'I .11 ■• I ■ r,;|;. '% PLATE 36. Fio-. 1. ;208. 9. Modiolopsis aviculoides. (Pag- 161.) 1 a. A \-iew of the lel't valve nf this specimen. I 6. Dorsal view of the same. Fig. 2. 210. 1. AvicuLA TRENTONEKsis. (Pag- 161.) 2 a. A worn specimen, showing only obscure traces of the radii, with strong concentric ridges. 2 b. A similar specimen, with obscure radii, having the anterior wing more extended. 2 c. The opposite valve of a specimen of similar form as the last. 2 d. A large specimen of the left valve, with strong radii. Fig. 3. 211. 2. AvicuLA ELUPTicA. (Pag. 162.) Fig. 4. 212. 1. Ambontchia bellistriata. (Pag. 163.) 4 a. Lell valve of a very symmetrical specimen. 4 b. Right valve of a larger specimen. 4 c. Profile view of the same. The specimen appears to be inequi- valve, which is due to the sliding down of one valve below tlie other, as is clearly shown in the lower part of tile figure, and in 4 b, 4 d. A portion of the surface enlarged, showing the fine undulating striae, crossed by the concentric lines of growth. Fig. 5. 213. 2. Ambonychia orbicularis. (Pag. 164.) 5 a. Right valve of a specimen, showing the muscular impression. 5 b. Left valve, retaining a portion of tlie shell, which is beautifully ornamented by radiating and concentric strise. .') c Anterior profile view of a single valve. ' 6 rf. A portion of the shell enlarged. Fig. 6. 214. 3. Ambonychia amygdalina. (Pag- 165.) 0 a. Right valve of tliis specimen. 6 b. Profile from the posterior side. 6 c. Profile of the anterior extremity, showing a kind of lunule below the beaks. Fig. 7. 215. 4. Ambonychia tjndata. (Pag. 165.) 7 a. Right valve of a specimen which is imperfect on the lower side. 7 b. Profile of the same, looking upon the posterior side. Fig. 8. 216. 5. Ambonychia obtusa. (Pag. 167.) 5 a. Right valve of this species. s b. Profile view from the posterior side. Fig. 9. 217. 6. Ambonychia 1 (Pag. 167.) y a, b. View nf the single valve, and profile nf the same. T!llSlfTiS5r SIEMlgSTDJ^S . PI -.Mi A OBPH A I. A .'/' % m a)' sTONt B t r. swiTQ-j .i'H 0- 0 I. W ENDCO"^ • ■O'^f (.0^ ,1' -'-<■!■• :-t I >'\'-' ji_ ■ U.Ml'. -\<> .'J.'!) ' -.;.,' .'..i ... j..! .; (,VTI v-o'i) ■y .a,:j.K02CiI!'i:i.i i >.<{ 'M ' 1 . ■•■-..1/ mi; ■ ,■•-. -.in i.j ii:!fv . % ^ . ) 1, . I 1 PLATE 37. Fig. 1. 218. 1. HoLOPEA SYMMETRICA. (Pag. 170.) Fig. 2. 219. 2. HoLopEA OBLIQUA. (Pag. 170.) 2 a. View of the aperture of a small specimen. 2 b. View of the back of the sliell. 2 e. Profile view. 2 d. Bade of a larger specimen. Fig. 3. 220. 3. HoLOPEA paludinifokmis. (Pag. 171.) 3 a. View of the back of tlie shell. 3 b. View of the aperture. Fig. 4. 221. 4. HoLopEA ventricosa. (Pag. 171.) 4 a. View of the back of the spire. 4 b. View of the top of the spire. Fig. 5. 222. 10. Pleurotomakia subtilistkiata. (Pag. 172.) 5 a. View of the spire of a large specimen. f> b. Profile of the same. 5 c, d. View of the spire and profile of the largest specimen seen. Fig. 6. 223. 11. Pleurotomaria lenticttlaris. (Pag. 172.) 0 a. View of the spire (the specimen is a cast). 6 b. Lateral view, showing the elevation of the spire. 6 c. Base of a smaller specimen (a cast), showing the umbilicus. 6 d. Front view, showing the aperture. Fig. 7. 224. 12. Pleitkotomaeia rotuloides. (Pag. 173.) 7 a. View of the aperture and front of the shell, showing the elevation of the spire. 7 4. View of the top of the spire. 7 c. View of the base, showing the umbilicus. Fig. 8. 225. 13. Pleuhotomaeia sitbconica. ( Pag. 174.) 8 a. Front view of a specimen preserving the shell in a very perfect manner ; the aperture imperfect. S b. Base of the same, showing the small partially closed umbilicus. 8 c. An enlarged portion of the surface, showing the cancellated striae which are scarcely visible to the naked eye. 8 d. Cast of another specimen. 8 e. Front view of the same, showing the form of the aperture. Tl&Mm^r'CiTf ai]im]ii£3=2''£JST2iS ( (1 A S 'L R O 1' O li A ) ^^ ^ V^^i^ ..- J- 7 C Kruyu'^i* Prmtod^Tijt.nil'Hib.r PLATE 38. Fig. 1. 74. 7. ^Pleurotomaria umbilicata. " (Pag. 175.) 1 a. Back of the shell, showing an elevated spire. 1 b. Front view, showing the aperture. 1 c. Base. 1 d. Top of the spire of a larger specimen. 1 e. Front view, showing a depressed spire. 1 /• Base. 1 g. Specimen from iVIineral Point, showing a greater elevation of the spire. Fig. 2. 226. 14. Pleurotomaria indenta. (Pag- 176.) Fig. 3. 227. 15. Pleurotomaria ambigua. (Pag. 176.) 3 a. View of the back of the spire. 3 b. Front of the same, showing the aperture. Fig. 4. 228. 16. Pleurotomaria percarinata. (Pag. 177.) Fig. 5. 229. 6. Murchisonia bicincta. (Pag. 177.) 5 a. Front view of a nearly perfect specimen, showing the form of the aperture. .5 b. Back view. ■ 5 c. Front view of a specimen with the last volution broken otT behind the aperture. 5 d- View of an imperfect specimen, showing the direction of the striae. 5 e. Enlarged view of the same. 5f. A smooth cast from crystalline limestone, scarcely preserving the upper carination in an obscure angle. 5 g. A large imperfect specimen, still preserving the striae upon the surface. 5 h. A portion of the same enlarged. Fig. 6. 230. 7. MuECHisoNLi teicaeinata. (Pag. 178.) 6 a. View of the back of the shell. 6 b. Front view, showing the aperture, which is imperfect on the outer side. G c. A fragment apjiarently belonging to the same species ; but the stri^ are much better preserved, a'ld tlie carina: sharply jjrojecting. Fig. 7. 231. 8. Murchisonia perangulata. (Pag. 179.) 7 a. Back of the spire, showing six volutions. 1 b. A portion of the surface, with the stria? enlarged. Fig. 8. 232. 9. Murchisonia uniangulata. (Pag- 179.) ■0fSTglS'"f?f'!J3'^ SiESSl^S^^SSls^ IM 3 8 -^ ( r, & s T R o p o n A . ) y.a '**»:*sijii»*-'- \ A \ k .1 /,. Xst'- S^ ^■^u ^ w 4^ 4 v^' .//: A Oir STOTJE BT STTINTON LITK OF r KICHELITI N "V O RK . PLATE 39. Fig. 1. 233. 10. MiracHisoKiA bellicincta. (Pag. 179.) 1 a. A small imperfect specimen, preserving the striae and mesial band in a very perfect manner. 1 d. A specimen with the strise partially removed, showing the extension of the aperture belovf. 1 c. A cast, showing the form of the aperture, which is nearly entire. 1 d. A fragment of a larger specimen, preserving the strife and mesial baud. 1 e. Cast of a large specimen, the lower volution broken off. Fig. 2. 234. 11. MuECHisoNiA suefusiformis. (Pag. 180.) i a. View of the back of the spire ; the apex imperfect. 2 b. View, showing, imperfectly, the form of the aperture. 2 c. A large imperfect individual of this species. Fig. 3. 235. 12. Murchisonia vittata. (Pag. 181.) 3 a. View of the back of the spire. 3 b. Partial front view, showing a part of the aperture. Fig. 4. 236. 13. Murchisonia gracilis. (Pag. 181.) 4 a. Fragment showing six volutions. 4 b. Another fragment, showing one of the lower volutions partially covered by the shell. 4 c. A small fragment, on which the shell is partially preserved. Fig. 5. 237. 1. SiTBULiTEs elongata. (Pag. 182.) 5 a. Imperfect cast of a large specimen, showing a part of the aperture. 5 6. A specimen preserving a portion of the shell, and showing the great length ol the last volution and aperture. .5 c. A fragment preserving the shell, and showing more distinctly the banded suture 'jpasEJifoss iLns2ssw®a/3„ I' I 7,! / CO. 2 6 /«' « n S i fjl STONE BY r SAr.NTON 6. ft W. CNDICOTT LlTM. N. YOlPi ■t NT' If (.Of? I .iM.M ) ')■ ■.iti\ .lit ', \ I-, .,,'.1 M .\hSi PLATE 40. pig_ i_ 238. 1. Caeinaropsis carinata. ( Pag. 183.) 1 o, b. Lateral and dorsal views. 1 c. Lateral view of another specimen, showing a more elevated carina. Fjg. 2. 239. 2. Carinaropsis patelliformis. (Pag. 183.) 2 a. Dorsal view. - *■ Lateral view of the same specimen. Fig. 3. 240. 1. Belleeophon bilobatus. (Pag- 184.) 3 a. Dorsal view, showing the sinus of the aperture. 3 b. Lateral view, showing the involution of the whorls. 3 c, d. Two views of a smaller specimen. • Fig. 4, 5. 241. 2. Bellerophon bilobatus, uar. actjtus. (Pag. 185.) 4 a, b. Dorsal and lateral views of the specimen. 5 a, b. Another variety, apparently due to pressure. Fig. 6. 242. 3. Bellerophon bilobatus, var. corrugatus. (Pag. 185.) 6 a. A specimen which is in a stone with three others, only one of which shows a slight development of the dorsal folds. 6 6. A specimen less distinctly corrugated. Fig. 7. 243. 3. Bucania expansa. (Pag- 186.) 7 a. View of the back of the shell, showing the strong carina, expanded aperture, and sinus on the dorsal margin. 7 b. Lateral view of the same. 7 c. Transverse section of the last volution, below the aperture. 7 d, e. Lateral and front view of another specimen, from which the expanded portion of the aperture is broken off, and showing also a little deviation in form. Fig. 8. 244. 4. Bucania bidorsata. (Pag- 186.) S a. Dorsal view of a small specimen, preserving a portion of the shell. 8 b. View of the aperture, which is very imperfect. 8 c. A fragment, showing the carinae and dorsal band very distinctly. 8 d. The same enlarged. 8 e. Cast of a larger specimen, imperfect towards the aperture, and showing only the broad dorsal carina. 8/. Lateral view of the same, showing the umbilicus. 8 g. Section of the last volution below the aperture. wjajaJtYit'^yr iCiiciacasa'a'ms.Tm (OA S TR O 1> O I) A ; 7« i» 1 d ^^ i:r«Kri.bj-SMH«U. f.ngti»in*i. i>r vi»*Wi:l)«tlii* PLATE 40 A. Fig. 1. 245. 5. BucANiA punctifeons. (Pag- 187.) 1 a. Dovsal view of a small specimen. 1 6. Lateral view, showing the umbilicus. 1 c. Dovsal view of a larger specimen, showing the elevated carinal band, which does not rise above the sur- face on the lower part of the shell. 1 d. Lateral view of another specimen, showing the side of the shell, which is obtusely angular, with obscure longitudinal ridges. 1 e. A portion of the surface enlarged. Fig. 2. 246. 1. Cyrtolites compressus. (Pag. 188.) 2 a. Lateral view of a specimen, having the sinuous lamellae at the ordinary distance asunder. 2 6. Dorsal view of the same. 2 c. Lateral view of a specimen, where the elevated lamellae are more distant. 2 d. Lateral view of another, showing the lamelte closely arranged. 2 e. A cast, which is smooth, with the exception of the elevated carina. 2/. A portion of the surface enlarged, showing the finer transverse and limgitiidinal stria?, and the subnndu- lose appearance of the surface. Fig. 3. 247. 2. Cyrtolites trentonensis. (Pag. 189.) ^ a, h. View of the upper surface of two individuals. 3 c. Lower surface of the same. 3 d. Dorsal view. Fig. 4. 249. 1. Trocholites ammonius. (Pag. 192.) 4 a. A small perfect specimen, showing the lamellose striae in great perfection. 4 4. A large specimen, preserving the lamellose surface. 4 c. Dorsal view, showing the archings of the stride upon the back. 4 d. A specimen denuded of the shell, showing the septa and deep outer chamber. 4 e. Section, showing the position of the siphuncle. 4/, g. Lateral and dorsal view of a fiagment of an inner volution, sfiowing a slight undulation of the septa on the back. 4 A. Lateral view of a fragment partially denuded of the shell, showing only the oblique transverse ridges. 4 i. Dorsal view of the same, showing the arching of the stri« upon the back. 4 le. Section of the same, showing the position of the siphuncle. ■".c m:sr'r'ap®i^ :LE)]iMi3Egs'-ir'©:iT:si (r. A s'l- m* ro n ,V A C i: !■ It A J.O iM) r) A / .r t 3) ^-:A 3b J ■y.i f -»!>.«. Vj-M'»- Hill- I K.M PLATE 41. Fig. 1. 247. 2. Cyrtolites trentonensis. (Pag- 189.) 1 a. Lower surface of an imperfect specimen. 1 4. A portion of the surface striae enlarged. 1 c. Section of the shell below the aperture ; the upper surface of the figure being the dorsal margin. Fig. 2. 250. 1. Cyrtocekas lamellosdm. (Pag- 193.) 2 a. Lateral view of the fragment. 2 h. Dorsal view of the same. 2 c. Magnified portion of the surface. Fig. 3. 248. 3. Cyrtolites filosttm. (Pag. 190.) 3 a. Lateral view of the specimen imbedded in stone, the apex being concealed. 3 b. View of the dorsal side of a small portion of the shell, showing the arched stria?. Fig. 4, 5. 251. 2. Cyrtoceras annulatum. (Pag. 194.) 4 a. A large fragment (a cast), retaining the annulations. 4 4. A smaller fragment, retaining the shell and transverse striae. ~"' 4 c. Section of the last, showing the siphuncle. i d. A portion of the surface magnified. r . 5. A fragment of the same species, nearer the aperture. Fig. 6, 7. 257. 1. Omcoceras constrictum. (Pag- 197.) 6 a. View of the ventral side of an imperfect specimen. G 4. Lateral view of the same, showing the sudden contraction below the outer chamber : aperture imperfect. 6 c. Section of the lower extremity, showing the small dorsal siphuncle. 6 d. A smaller specimen, of the same form as the last. 6 e. A shorter and more ventricose specimen. (The transverse lines on the npper half of the figure, indicating septa, are incorrect.) iif. The apicial extremity of the fossil. 1 a, c. Dorsal and lateral views of a fragment, showing the direction of the septa. 7 4, d. Sections of different specimens, showing the position of the siphuncle, and the narrowing of the dorsal side of the sliell. ( CYKTdCERAS fc' ) f^ Xa ^1 ■ II 1 1>^_ l-l. 41 4c id fi 4i % OH STOire BT F SWDITON UTH or G. i W, ESTDICOTT, 5 9, BEEliMANST M. YOB^Jl PLATE i± Fig. 1, 3. 2b2. 3. Cyrtoceras macrostoivhtm. (P^g- 194.) 1 a. A fragment, showing a partial section. 1 i. A large fragment, showing the wide outjer chamber. 1 c. Section of the smaller extremity of the last. 3 ft. Dorsal view of a fragment ]irohably identical : tlie sti'ive in tlie tigure do not bend so abruptly as in tile original. -3 b. Lateral view of the same. Fig. 2, 3. 253. 4. Cyrtoceras constrictostriatum. (P^g- 195.) 2 a. A fragment, showing several of tlie septa and a part of the outer chamber. 2 4. Transverse section, somewhat compressed, showing the position of the siphuncle. 3 e. A fragment, showing the surface markings. 3 d. Section of the same, wliich does not show the sipliuncle. Fig. 4. 254. 5. Cyrtoceras MULTicAMERATnM. (Pig- 195.) Fig. 5. 255. 6. Cyrtoceras arcuatum. (P^g- 196.) 3 a. Lateral view of the specimen, which is cruslied towards tlie lower extremity. 5 b. Section of the same. 5 c. The base of a parasitic coral, or of a crinoid, attached to the lossil. Fig. 6. 256. 7. Cyrtoceras cAMtrRUM. (Pag. 196.) Fig. 7. 258. 11. Orthoceras arctjolibatum. (Pag. 198.) 7 a. A fragment near the apex of the shell. 7 A. A fragment of larger diameter, showing the convexity of a septum. 7 c. Transverse section, sliowing the central position of the siphuncle. Fig. 8. 259. 12. Orthoceras teretiforme. (Pag- 198.) S a. Fragments of two specimens connected by tlie dotted lines. The annulations are represented too broad. s b. .Section showing the position of the siphuncle. 'i?aasy'K'®ss aH3aj3S'5?®JvV5ii, n 4.; ( cyhtoceras *>■ Za Ji X. STONE BY P SVrrNTON LITH OP G i W ESDICOTT, 5 9 BKKKMAK3? N ^'O-U'v r*f I '."( "(.'I .\'M: I l-tj' -OV .:.'' fW: -MiH ) PLATE 43. Fig. 1. 260. 13. Orthoceras textile. (Pag. 199.) 1 a. A fragment of the natural size. 1 b. A portion of the surface enlarged, to show the striae. Fig. 2. 261. 14. Orthoceras BiLiNEATUM. (Pag. 199.) 2 a, b. Views of two individuals, showing the annulations and longitudinal striae. 2 c. Transverse section of b. 2 tl. Portion of the surface enlarged. Fig. 3. 262. 15. Orthoceras bilineatum, var. a. (Pag. 200.) 3 a. A fragment of this variety. 3 b. Transverse section, slightly compressed, showing the siphon. 3 c. An enlarged portion of the surface, 3 rf. A fragment denuded of the shell, showing the lines of septa which do not correspond to tlie annulations. Fig. 4. 263. 16. Orthoceras clathratom. (Pag. 201.) 4 a. The fragment, natural size. 1 b. Magnified portion of the surface. 4 c. Transverse section. Fig. 5. 264. 17. Orthoceras vertebrale. (Pag- 201.) .') a. Ventral side of the fragment. 5 i. Portion of the dorsal side. fi c. Transverse section. Fig. 6. 265. 18. Orthoceras anellum. (Pag- 202.) 6 o. A fragment of the septate portion of the shell. 6 6. Transverse section of the same. (J c. Enlarged portion, showing the stris, which, on a great part of the surface, are covered by a calcareous coating. 0 (i. A smaller fragment. 6 e. Transverse section. 6/. Portion of the surface enlarged. Fig. 7. 266. 19. Orthoceras unduldsteiatum. (Pag. 202.) 7 a. Ventral side of a fragment, showing the nearly transverse direction of the annulations. 7 b. Dorsal side of the same, the specimen cylindrical. 7 c. Transverse section of the same. 7 d, e. Two smaller fragments of the species, compressed in different degrees. If, g. Transverse sections of the two last. 7 h. An enlarged portion of the surface. 7 i, k. Another fragment and section, showing the position of the siphuncle. Fig. 8. 267. 20. OmnocEK as {O. trochlear e?). (Pag. 203.) ic :a:ai£f'ii''as3' irjicsi?!:^ S'TjvOJ.'vra ( O H ■[' II () C K It A '(■ A ) m "^^^ T>Ta>fn 'by'y.rt Hikll E&rfr«T<>ii-?Tia!rdlrr 'Sar-.rtD'itln.e as^. ■^i ',"'-1 \o -,' ■ ' -■;■ ■ ' I . . ( PLATE 44. Fig. 1. 273. 5. Endoceras annttlatum. (Pag. 207.) 1 a. Lateral view of a fragment, showing the arching of the annu'ations towards the left side. The fine dark transverse lines indicate the edges of the septa. 1 b. Longitudinal section, showing the position of the siphuncle, convexity of the septa, and internal tutes. '2'mmiJS"s'®M ai£Sffiii^'i?®»i'^' M 4 4 I OnTIKlCF.RATA . i N Ik ^ '11 .■a*; '";>i- 'S, ' :- i!i .H?^r , r s^ .^ OS !T0 JE BT y SiVltlT OH L:Ta OT S I "».■ S^i'ClTT. 59 .1r:(,HMAn Si PLATE 45. Fig. 1, 274. 6. EnDOCEEAS PROTEIFORME, ««?•. TENUISTKIATUM. (Pag. 209.) 1 a. Fragment of the young shell, natural size, showing only the transverse striaa. 1 b. Enlarged portion, showing the longitudinal striee. Fig. 2, 3, 5. 275. 7. Endoceras pkoteiforme, var. tenuitextum. (Pag. 210.) 2 a. A fragment of a tube destitute of septa, presenting strong transverse and longitudinal striae. 2 J. A portion of the surface enlarged. 3 a. A specimen with finer striae, showing the marks of septa. '3 b. Portion of the surface enlarged. 5 a. This specimen presents a double tube or sheath, the outer one (or embryo tube) being entirely smooth ; while the inner one, which is but little smaller, is marked by longitudinal and transverse striae as in the preceding figures. 5 i. A portion of the same enlarged to show the stria;. 5 c. A section of the same, showing no septa or siphuncle. Fig. 4. 276. 8. Endoceras proteiforme, var, uneolattjm. (Pag. 211.) 4 a. A young shell, with the outer chamber and apex broken off. 4 6. Transverse section of the larger extremity, showing the position of the siphuncle. 4 c. A fragment of the smaller extremity of the shell, which is annulated by fine sharp ridges. 4 d. The same enlarged. 4 «. A fragment of another tube, marked like 4 a, showing at the lower extremity a septum and siphuncle. 'jFiii.5gss"'s^®ss' asaciis'i?(n)ss"Sa IM 45 triiQCERATA. ) it i^C CN S'OUE 6v ^ ->»(,t,TON . V •J ^■-»r ^<^l I -tr W.ENDICarr LITH.NEV YOHK . PLATE 46. Fig. 1, 2, 3. 276. 8. Endoceras proteiforme, mr. lineolatum. (Pag. 211.) 1 a. A fragment of the parent shell, enclosing an embryo tube within the siphuncle. 1 6. Transverse section of the lest, showing the large lateral or excentric siphuncle of the old shell. The shell is crushed, as shown in the upper figure, so that a perfect section cannot be given. 1 c. The surface marking of the young shell, enlarged. 2 a, b. The external shell, and a longitudinal section of a young shell, which is destitute of septa. 3. This is marked upon the surface as other specimens of the var. lineolatum. The septa in the figure are erroneously represented by the engraver much more approximate than they are in the specimen. Fig. 4. 277. 9. Endoceras proteiforme, mr. STRANCfULATUM. (Pag. 212.) 4 a. A fragment, showing the contraction below the aperture. 4 b. Transverse section, showing the nearly central position of the siphuncle. 4 c. A portion of the surface of a specimen enlarged. 4 d, e. Two specimens denuded of the shell, showing a uniform character in the contraction of the tube, with a slight difference in the distance of the septa. 'li' 3if,a Jsjfw CO) m iti.miii iii a 'jf (0) isv i3j , PI 40 (ORTHQCKH ATA ) f i V^i 5?&--^ "1 ,'V 1 .> :^^. ON STDNE B* f Sl'Mi On . (k fc W ENOiCO PLATE 47. Fig. 1, 2. 274. 6. Endoceras proteiforme, var. tenuirtriatum. (Pag. 209.) 1 a. A small and slendei- specimen of this species. 1 A. A portion of the surface enlarged, showing the cancellated lines. 2 a. This specimen presents very similar surface markings, and cannot be distinguished from the last, though the transverse striffi are less prominent. The specimen consists of a double or triple tube; the outer one 2 b showing externally marks of septa, which are distant about one-lburth the diameter. The shell is exfoliated, and the surface markings are unl;nown. 2 e. An enlarged portion of the surface : the longitudinal stria; are too strong in the figure. 2 d. A small portion still farther magnified, showing the proportionate size of the transverse and longitudinal strise. 2 e. Transverse section of the specimen 2 a, showing the proportional diameters of the two, and the section of a still smaller tube within 2 a. Fig. 3. 269. 22. Orthoceras juncetjm. (Pag. 204.) .3 a. A fragment deniided of the shell, showing a part of the outer chamber, and septate \>ortion of the tube. 3 b. A smaller specimen, showing the marks of septa which appear to be slightly oblique. '■i c. A small fragment, showing the convexity of a single septum. '3 d. A section of the last, showing the central position of the siphuncle. i e. A small fragment, showing the closer approximation of the septa near the outer chamber. 3f. A small fragment, preserving the shell and the striated surface. Fig. 4. 276. 8. Endoceras proteiforme, var. lineolatum. (Pag. 211.) 1 a. A fragment from the apex of one of these tubes, which is septate as in the larger specimens. A b. A transverse section. 4 c. A fragment which is annulated near the apex, and septate to the extreme point. '1 d. Section near the apex. 4 c. A fragment of a similar young shell, where the lamellose stris have become vesicular, giving a rough scaly appearance to the surface. ic';isir'3r®»r itKMJi^imwn^ , PI. 4: im 1 HIM h;K VIA '% j^^ f:^: ^■■■i .^r h t '7 /^^ 1',' E. ;^^ f:' ^«[ >'■ : K-- j^; fe' - v'?-^' ^, \ - --..y . / ZH SlSNt H'i ¥' ^W'N , li\ LIFH 0- 0 I. * tNOtCOl t NtWVOftK PLATE 48. Fig. 1, 2, 3, 4. Endoceras proteiforme. (Pag. 213.) 4. A fragment of a large specimen, composed ot" twenty or more chambers, one sitle of \vliich is worn down, exposing the sipliuncle, which contains the embryo tube, within which is a young shell a. 4 b, b. The larger or embryo tube, which is broken at tlie lower extremity. 4 c. The siphuncle, the space surrounding the tube being filled with calcareous spar. This specimen shows, in a very satisfactory manner, the position of these tubes within the parent shell. A small portion of the upper part only of the embryo tube is preserved. .3. An embryo tube with a longitudinal section on one side, showing a slender septate tube within, whicli is nearly destroyed by weathering. ^. A similar tube, free from striie, and like the others. This tube has been broken at a, b, c ; and the trans- verse sections a, b, c, at the bottom of the plate, represent its appearance. The outer tube contains an inner one, which is septate througliont its entire length, and fiu-nislicd wilii an excentric sijjhuncle, whicli is distinctly i-epresented in the section a. I. A separate embryo tube, nearly perfect, and showing some ineiiualities near the l)ase, apparently from con- tact with the inner side of the siphuncle. V2ii^ij!r'-j'®5j5r ■&mmmsfm))^im. OK rlHIlK ATA \'\ 4>S. ai'- \^ -ms: i: ■ m -I i'/. ds ■> "■■' '•3 \ y -N .S'rONE BY F JWIKTSN LITH jr J 4 W KNDlCU'ir. 59 BKF.KMAB iT N YOK' (.tf: ^1,V! . 'Z-!>- .. -y-ii PLATE 49. Fig. 1. Endoceras proteifoeme. (Pag. 213.) 1 a. Ventral side of a fragment, showing the siphuncle, which is worn through in the lower part, exhibiting the smooth embryo tube. This specimen shows the more abrupt arching of the septa as they approach the siphuncle. I 6. A fragment, preserving the embryo tube. 1 c. Transverse section of the last, which is slightly elliptical from compression. The embryo tube is pressed against the upper side of the siphuncle, the outline of which is only faintly represented. 1 d. A similar fiagment, embracing a portion of the embryo tube. In this one the septa are a little more ap- proximate than in the other specimens, but it does not differ in other respects. 1 f. A nearly perfect embryo tube, with a few of the septa of the parent shell still attached. In all these specimens, the septa are distant one-fo\irth to one-sixth the diameter of the outer shell. 'ffaSM'S'ffiir ILKftSm^'JTiolSfTS o I' I 49 IIRTHtirBRA TA ^^.^liJ. - E Sc <«' EKBICOTT LITM « ^OW. PLATE 50. Fig. 1, 2, 3. Endoceras photeifoeme. (Pag. 213.) 1 a. An embryo tube containing a young shell. This specimen is more elongated, and less rapidly attenuating than the prevailing forms of the species : the outer tube is smooth, while the inner one is striated. 1 h. This tube is more slender than the usual forms, but does not differ in other respects. 2 a, b. Fragments of smooth embryo tubes, apparently of the same species, differing only in being more suddenly contracted and aculeate near the apes. 2 c, d. Parts of the siphuncle separated from larger shells, still retaining the embryo tube within. The si- phuncle is marked by oblique or ascending annulations, indicating the junction of the septa ; which direction of the annulations is due to the lateral or escentric position of the siphuncle. 3. An embryo tube, more conical than any of the others. Tmiss^iFiBS?!' %EmTi smo)i^i3;,. PI f)0. ( () r< r II II c I. K /VTA \: 1 /o- ■t;ti i w-- ->-^ |S'« B-« Mm ^ M 3 T list by f 3W.S.0N i.iTii Of .■; t y/ tMiiicorr. 59. iiFhHX».'i si :i PLATE 51. Fig. 1. 270. 23. Orthoceras amplicameratum. (Pag. 205.) 1 a, b. Parts of tho same individual, preserving a large portion of the outer chamber, with an c(|ual length of the septate part of the tube. I c. A transverse section of the specimen, at the upper extremity of 1 a, showing the excentric position of the siphuncle. \ d, e. A. fr^ment of another specimen, showing the same distance of the septa and excentric position of the siphuncle. 1 /. A fragment of the septate portion of a much larger specimen. 1 g. Transverse section of the same, showing the position of the siphuncle. Y\g.2a,b. 279. 11. Endoceras arctiventrum. (Pag. 217.) Fig. 3. 280. 12. Endoceras angusticameratum. (Pag. 218.) 'S'siiwiF(o)sr 5^,JiMT,sg'ip®Kia„ I'l. 51 ( IIRTIIUI l.RATA ) ;'.] r ;'/' J H •Jf sr OKB B? !■ SW.fi r OK Lira OF 0 4 W tUlK. OTT >9, BSERMAN IT .1 fOKr. M^ $'. ' '.,!'( .'.II r.'oai Ml . /:. -■.'f.---,;l ■ I /SI«: .v.,i:H .I'i ,1' » • PLATE 54. Fig. 1. 268. 21. Orthoceeas latiannulatum. (Pag. 204.) 1 a. A fragment, showing four chambers. 1 b. Section and siphuncle. Fig. 2 a. 283. 15. Endoceeas appeoximatitm. (Pag. 219.) Fig. 2 b. 282. 14. Endoceeas magniventetjm? var. (Pag. 218.) « ^'isiiss"tf S'ji'i' iiCSSSri-; "s^^'Ji^n's PI r.4 ; ORTHIUKHA r.\ ) Ja / /, f -*SfeJ!¥^;<„s %- 'fc-V ^m ■V■« STOKE BT V IVAi-.i'. ■_ .< I :^;r^ ^;, i'\:^.^:i u.'.j,. i ; .(■ <■_■ PLATE 56. Fig. 1. 271. 24. Orthoceras steigatum. (Pag. 205.) I a. A young specimen, with the shell partially exfoliated ; a few of the septa being indistinctly visible. 1 b. A fragment, showing the shell in a considerable degree of preservation. 1 e. A portion of the surface of the last enlarged, showing the flexuous character ofjthe strise. 1 (/. A large specimen, preserving but indistinctly the striaj. About twenty of the chambers are preserved, as well as a large part of the outer chamber. This specimen shows a small septate tube within the open extremity, but it is probably accidentally present. If,/. A fragment, showing five chambers, with a section of the same. Fig. 2. 17. 2. Orthoceras laqueatum. • (Pag. 206.) 2 a. A fragment imbedded in compact limestone. 2 6. A small fragment, showing the intermediate finer striffi. 2 c. A portion of the surface enlarged. Fig. 3. 272. 25. Orthoceras laqueatum ? var. a. {Pag. 206.) Fig. 4. 286. 1. Cameroceras trentonense. ( Pag. 221.) 4 a. A fragment of the shell, preserving about three of the chambers, beyond which the siphon is extended to an equal distance. ■1 b. Another fragment, with the siphuncle still more extended. ■1 c. Transverse section, showing the position of the siphuncle. TriEIgS?Tf®Sy Io2MSS'B'®KflS.. PI 5ti ^ORTBOCKRATA * ,im i w- i-\ ON SI ONE BT F SWtNION LrTH OF 6,1,* LNOjCO'^T nCW irO^ * 0-" -I- ..l>,i;-i. PLATE 58. Fig. 1. 285. 17. Endocekas DisTANs. (Pag. 220.) 1 a. A weathered cast of a fragment of this species. 1 b. Transverse section of the smaller extremity of the same, showing the large siphuncle. Fig. 2. 89. 1. Oemoceeas tenuifilum ? (Pag. 222.) 2 a. Part of a siphuncle, with a small portion of the shell adhering. 2 6. A fragment worn down on one side somewhat obliquely, showing the siphuncle in the lower part of the figure. 2 c. Section of the same. ' TaSM-iriM ILHMIIigli-'fflJiyjg o \'\ .)« uniHot-fc.R ATA ) ^S^isw^-"" ''•^ir>;ui'>'^i-Ti^'*%; » fc *f EMUeOT-: i.JTH H fO». . '] I ( ;'-;i-' 1/ 1 .--i, ,,!i; ■. n 11.1 PLATE 59. Fig. 1, 2, 3. Endoceras troteiforme. (Pag. 216.) 1 a, b. Var. tenuitextum. The surface markings on two different specimens, somewhat enlarged beyond the natural size. 2 a, b. Var. tenuistriatum. Tlie surface markings on two different specimens, both sliglitly magnified. 3 a. Var. i'meolalmn. This presents only transverse striae ; but some specimens show minute longitudinal ones, passing into the preceding variety. 3. Var. I'meolatum. The surface is covered by fine spots or stigmata, as if some adhering softer substance had been separated from it. The same is observed in 2 b, in a less degree. Fig. 4. 287. 1. CoNULARiA trentonensis. (Pag. 222.) 4 a. A specimen (natural size), with the apex broken off. '1 b. Another specimen, more abruptly acute. A c. Transverse section of 4 a, near the apex, showing the septum and siphunclc. '1 d, e. Lateral and transverse view of a fragment, showing the convex septum. 4/". A portion of the surface enlarged. Fig. 5. 288. 2. Conularia geanhlata. (Pag. 223.) 5 a. A specimen nearly entire, giving the general form of this species. 5 i. A portion of the surface enlarged. Fig. 6. 289. 3. Conularia papillata. (Pag. 223.) 0 «. An imperfect specimen, of the natural size. C 6. A portion magnified. Fig. 7. 290. 4. Conularia gracile. (Pag- 224.) 7 a. A specimen {natural size), the apex broken oft'. 1 b. A portion of the surface enlarged. TPB13S152'©H IklISi::^-..^l.JB. [ CUPUALoruDA.] PLOD. * # /i:- . •/ PLATE 60. Fig. 1. 291. 1. Ogygia? vetusta. (Pag. 227.) Fig. 2. 292. 3. AsAPHUs? EXTANs. (Pag. 228.) 2 a. A caudal shield. 2 b. Lateral view of the same. 2 c. Another fragment, showing nine articulations of tlie thorax. Fig. 3. 293. 1. Calymene multicosta. (Pag. 228.) Fig. 4. 40. 2. Ill^nus ceassicattda. (Pag. 229.) 4 a. The caudal shield of a large individual. 4 b. Middle lobe of the cephalic shield, the lateral portions being separated at the sutures. 4 c. Lateral view of a small entire specimen. 4 d. Dorsal view, showing the great width of the middle lobe, and abrupt incurving of tlie cephalic shield. Fig. 5. 294. 3. Ill^nus trentonensis. (Pag. 230.) Fig. 6. 295. 4. Ill^nxjs latidoksata. (Pag. 230.) li a. The fragment, natural size. li b. Three of the articulations enlarged, showing tlie lamellose strite. Fig. 7. 43. 1. IsoTELUs gigas. (Pag. 231.) 7 a. A specimen preserving the thorax, caudal extremity, and central lobe of the buckler. (The base of the latter is too far extended in the engraving.) Tlie caudal shield is denuded of the shell. 7 b, e. The maxillary portions or cheeks of the buckler. e, e. The eyes. 7 d. Inside of the lower crust of the cephalic shield, the upper part having been separated at the lateral suture. 7 e,/. Lower side of the cephalic shield, towards the extremities of which the upper and lower crusts are folded together, so as to present the appearance of projecting spines. 7 g. Tlie epistoma or labrum, the place of which is indicated in the centre of the lower side of the previous figure. Two circular depressed spots are represented, which are always observed in w^ell preserved specimens ; these probably indicate the points for the attachment of muscles or tendons upon the inside. 7 h. Central Inbe of the cephalic shield. 7 ?. Same part of a larger individual. iBirmiDSiiirii ^^Tisii^^5if®S5rig n (;n I TKI i.iiiii r K ; OK STDNf BY F SWiN TON - LIT! or S 1 W. ENDICOTT. N YORK. PLATE 61. Fig. 1. 306. 3. AsAPHirs ? NODOSTRIATUS. (Pag. 248.) 1 a. The fragment, natural size. 1 b. A magnified portion of the surface, showing the lamellose stria;, witli small nodes which interrupt the lines. Fig. 2. 303. 4. Ceratjkus? PTTSTTiLosus. (Pag. 246.) •2 a. The fragment, natural size. 2 6. A magnified portion of the same Fig. 3, 4. 43. 1. IsoTELUs gigas. (Pag. 231.) 3 a. The buckler of an individual of medium size. This is more extended in front, and the eyes are more prominent than usual. 3 b. The caudal shield, corresponding in size to the buckler. The crust is removed, showing the lines of the articulations. 3 c. A portion of the surface of the buckler enlarged, showing a peculiar punctate structure which is scarcely visible to the naked eye. ■ 3 d, e. Lateral and dorsal views of a small perfect specimen from Kentucky. The buckler is somewhat com- pressed or bent in front, so that the facial suture is not shown to its full extent. 3/ Buckler of an individual of ordinary size. The eyes are prominent, but less proportionally elevated, ami the whole less convex than the specimen 3 a. The course of the facial suture is distinctly visible. 3 g. Caudal shield corresponding in size to the buckler 3/ ; the marks of the transverse segments scarcely visible. 3 h. View of the eye of 3 /(natural size), as seen looking forwards and outwards. 3 i. Oblique front view of the eye, which, under ordinary magnifying glasses, presents no granulations. 3 k. The labrum or epistoma, showing the inner or upper side. 3 m. A portion of the same enlarged, showing the strise upon the surface. 4 a, b, c. Front, lateral, and dorsal views of the original specimen to which Green applies the name of /. ryclops. 'M'JEJIB'T!;'® ffl' IC,II5iJi;5§ §5 WdDOTJS n c H I i.«i II I r K a ^ -t*'.5^^?^"^>'' .■> (' ^ /a 3d -^ . vV.v'tWss.s .-if m -rtf- f. ^^§' :ili' '^ f / ON STONt: Bl r XWra ION . LITH «F 6. 8 W ENDICOTT N YD .T*. PLATE 62. Fig. 1,2. 43. 1. ISOTELTJS GIGAS. (Pao^. 231.) I a. A specimen folded so that the two extremities meet. The fossil is rarely found in this condition ; and in many instances where it has originally assumed this form, it has been subsequently crushed. 1 b. The caudal shield of a young individual, showing the marks of the articulations, and preserving the tri- lobate form more perfectly than older specimens. 1 c. A magnified portion of the surface of one of the articulations of a large individual, showing, in addition to the punctures upon the surface, a series of curving impressed lines. The latter are not observed upon the buckler or caudal shield, which preserves a double series of punctures as shown in PI. 61, fig. 3 c. 2. A specimen with the crust almost entirely removed. The upper part of the cephalic shield has been se- parated at the mai'ginal suture, leaving tlie lower portion with the epistoma attached as represented in the figure. :t' ]iiiei^iV-li?f.t))lV ILillimiivi ^j»«wiil>]rX»»S*i: r n,'tk'»ifc'r»^''J "J — »»i''' juiii' PLATE 63. Mg. 1. 43. 1. IsOTELUS GIGAS. (Pig- 231.) • The lower figure represents the caudal shield, and five of the articulations of a very large specimen. The superior covering is removed, sliowing tlie converging stria; in the dee]i grooves along the margin. Tlie individual, when perfect, could not have i>een less than nine or ten inches in length : the buckler is of nearly corresponding size. The narrow thickened border, and course of the facial suture, are well shown in tlie specimen. The posterior angles are represented in the figure too much rounded, the one from being broken, and the other from being covered by the stone. The eyes are nearly perfect, and re- markably prominent. TIESMfSS? Ty.-illMDt^'^rm'^m . n tA TKII.IIBITRS \ ^ ^^\ ^^"•,'' J k ■^■^•-; '• f^ %: *■-*-. f.-^-^-^^. ■ m % f ^ f ON STONE BY F. SWJNTON LITH OP a »• W EmrcOTT }JEW YORK- l.ii. '/i: '.'.'i' ,„.i',.H ,:...!,/ I't; I HO .v,.'7': , . ,| , .. ■ , ' I ■ PLATE ()4. Pier. 1. "296. 1. Platynotus trentonensis. (Pag- 235.) 1 a, h. Portions of the buckler and caudal shield of this species. 1 e. A fragment of the buckler, more compressed than the preceding. 1 d. A magnified portion of the crust, showing the pustules upon the surface. 1 e. This figure is from a plaster cast of a specimen from the Blue limestone of Ohio. Fin'. ± 297. 2. Calymene becku. (P"8- 237.) 'i «. .-Vn imperfect specimen, preserving the thorax and caudal shield, and tlie left maxillary portion of the' buckler. 2 4. A perfect specimen, with the exception of the maxillary portions, which are separated at the facial suture. 2 c. A similar specimen, preserving the maxillai-y parts, which give a difi'erent outline to the cephalic shield. 2 d. Part of a single articulation enlarged, sliowing the spine upon the centre, with papillose surface. 2 e. A portion of the surface of the buckler enlarged, showing the papillose character of the surface. Fig. 3. 298. 3. Calymene sENAKiA. (Pag. 238.) 3 o. A large s\)ecimen from tlie Trenton limestone, witli the buclcler abruptly curved downward in front. 3 4. A small specimen from the same rock. 3 c. Lateral view of the same. 3 d. A small specimen from the Hudson-river group. 3 e,f, g. Three views of a contracted specimen from the Blue limestone of Ohio. 3 /(. Lateral view of the eye of this species, enlarged. The eye is obtusely conical, with a depression or cavity at the apex, which is granulated as shown in 3 i. From the oblique conical form, this depression opens outwards and upwards, being protected on all sides by a tliick crust. 3 k. The buckler of this species separated at the facial sutures, showing the form of the maxillary portions 7 /, which embrace more than half the oculiform tubercle. 3 I. Front view of the buckler, showing the termination of the facial sutures. ^ is the labrum, which occu- pies this position beneath the buclcler. 3 in. The same enlarged, showing the lines of the frontal suture, and the termination of the facial sutures. 3 n. The inside of the glabella, having the maxillary and basal portions separated. Fio-. 4. 299. 1. AciDAspis tkentonensis. (Pag. 240.) 1 a. Front view of the specimen, which is folded (natural size). 1 b. The same enlarged, to show more distinctly this part of the fossil. 4 c. Dorsal view (natural size). 4 d. The same enlarged. 4 e. The caudal extremity and part of the (liorax enlarged. 4 /. Margin of the maxilla; enlarged. Fifi. 5. 300. 2. AciPASPis .spinigei;. (Pag- 2-11.) Fig. 6. 305. 2. PiLACop.-^ !' LATicAUDVs. (Pag. 248.) ■•s" D5t m :i'j a' © 'iy li a itiic la; s ^' o 'xj m I'l I..V I T K I L O B I T K S ) 'v*^.' M\ J .^ $i^ cr^> -^yyjjtp PLATE 65. Fig. 1. 301. 2. Ceraurus pleurexanthemus. (Pag. 242.) 1 a. A nearly entire specimen, with the maxillary portions obscure or entirely removed. The buckler is par- tially crushed and obscured by soft shaly matter, and the oculilbrm tubercle very imperfectly preserved. The posterior prolongations of the buckler are distorted and obscure, as are also the spines proceeding from the caudal shield. I b. A specimen of the same partially folded, with the buckler curved forward and tlie margin broken oO'. The crust is partially exfoliated, so tliat the surface markings are not well preserved. i c. Front view of the buckler, showing the junction of the epistoma. 1 (/. A large imperfect sjiecimen, showing more distinctly the peculiar structure of the articulations. Tlie buckler is imperfect, but still partially preserves the posterior spines : the caudal spines are broken ofl'. (This specimen has been left by the engraver imperfectly represented.) 1 c. Lower side of the buckler of the last, showing the epistoma joined by a straight suture to the front of the glabella. i f. A separated labrum, with the upper margin broken off. 1 g. A buckler, with the maxillae removed. 1 h, i. The glabellae of two large individuals. 1 i*. A magnified portion of the surface. 1 k. A caudal shield, with the spines removed. I /. The spines of the caudal extremity, with a single articulation connecting them. View from the lower side. 1 m. The caudal shield, with the spines attached. 1 ni*^ A magnified portion of the surface. 1 n. A transverse section, showing the elevation of a segment, and the lateral extension of the articulations into fin-like processes. Fig. 2. 302. 3. Ceraurus vigilans. (Pag- 245.) 2 a. An entire specimen, preserving the posterior spines of the buckler. 2 ft. Front view of the same, showing the elevation of the oculiferous tubercles. 2 c. A small specimen with the surface markings obscure. 2 d. Lateral view of a specimen, showing the extension of the extremities of the lateral articulations. 2 e. Caudal shield of a larger individual. 2/. An enlarged poi-fion of the buckler of 2 a, showing pustulose tubercles. '2 g. The caudal shield and a portion of the thorax enlarged, showing the tubercles upon alternate and third segments. 2 h. Profile of the same. Fig. 3. 304. 1. Phacops callicephalus. (Pag: 247.) 3 a. Cephalic shield of this species. 3 ft. A small entire specimen. 3 c. The caudal shield of the last, showing the number of articulations, etc. 3 d. Magnified portion of tlie surface of the buckler, showing the pustulose-punctate character of Ihe surface. 3 e. A magnified portion of the articulations of the thorax, showing the irregular pustulose surface. 3/. Lateral view of the eye of this species. 3 g. Magnified view of the eye. 3 h. A contracted specimen. The lobes of the glabella are obliterated, and the surface of the eye crushed or absorbed. 3 /'. View of the same specimen, showing the caudal shield and front of the buckler. Fig. 4. 307. 1. Trinucleus concentricus. (Pag- 249.) ■ I n. The cephalic shield of this species, still preserving one of the slender spines from the jiosterior angle. Tlic posterior spine of the glabella is broken off, though the fracture is not conspicuous. -1 ft. Lateral view of the cephalic shield of a smaller specimen. 4- f. The cephalic shield of a small specimen, in which the glabella preserves its posterior spine. ^j'SiiKSTff'DS'r i£).x:«:ii s-■■,- \ ((( I M(ff , I I ' ^-4 f I>j«n.l-»- :;M M Ef,r* •■*■ ■-■ *' -I* » Tfni-t* PLATE m. Fig. 1. 301. 2. Ceraurus pleurexanthemus. (Pag. 242.) 1 a. A fragment of a large individual, preserving the buckler and eight articulations of the thorax. The sur- face is beautifully and evenly granulated or papillose, with larger tubercles upon the cephalic shield, and mamillary tubercles upon the articulations ; these are enlarged in the figures 1 b, c, d. 1 e. Front view of the specimen 1 a, showing the elevation of the oculiferous tubercles. 1 f. One of these tubercles magnified. When magnified to this degree, they exhibit only rounded granulations. 1 g. The cephalic shield represented in 1 a, showing the separation of the maxillffi J y sX the facial sutures. 1 //. The right maxilla, separated from the cephalic shield. (Tliis figure on the plate is without a number.) Fig. 2. 297. 2. Calymene beckii. ( Pag. 250.) 2 a. An entire specimen, with the exception of the maxillary shields, which are separated at llie facial suture, leaving the cephalic shield in the usual form. '2 b. An imperfect specimen, with the maxillary portions partially preserved, but separated at the suture, and pressed downwards. 2 c. The thorax and caudal shield, preserving the crust, with the tubercles upon the middle lobe, in a. very perfect manner. 2 d. The cephalic shield, with the maxillary portions separated at the facial suture. 2 e. Tlie cephalic shield entire, but so much compressed that the eyes are obliterated. The posterior angles are too much rounded in the figure ; in other respects, the true form of the buclder is represented. 2/. The cephalic shield preserved in compact calcareous stone. 2 g. A larger specimen, in compact limestone, preserving a more convex form in all its parts. 2 h. A small individual, preserving the thorax and the maxillary portions of the buckler, the glabella being separated. 2 i. Tlie maxillary shields, as they frequently occur in the slate, separated from any other part of the fossil. The lower figure is the labrum. 2 k. A single maxillary shield of this species. Fig. 3. 308. 4. CALYHEtiE (Species undetermimd). (Pag. 253.) 3 a. A part of the thorax, preserving eight or nine articulations. :i 4, Tlie caudal shield, with a few segments of the thorax. Fio-. 4. 309. 5. AsAPHtTS? latimarginata. (Pag. 253.) 4 a. The caudal shield of a small individual. 4 6. A fragment of the lateral lobe of the caudal shield of a larger individual Fig. 5. 43. 1. IsoTELus oiras. (Pag. 254.) The hihnitn or epist(jroa of a very large indiviilual. J*'- [ T It 1 I. u D I T U -< . 1 I'l 00 /S t a/ ■•trKr^-'^ , p«^W^ /«^- PLATE 67, Fio-. ]. 307. 1. Trinucleits concentricus. {Pag. 255.) 1 a. A large individual, destitute of spines upon the posterior angles of the buckler and glabella. The border in front of the glabella has three distinct rows of punctures, four in front of the cheeks, and five on each side, with six or seven near the base. 1 b. The thorax and caudal shield enlarged, to show more clearly the character of the segments. 1 c. A smaller specimen, preserving the spines of the buckler There are four rows of punctures in front, and six on each side of the buckler. 1 d. The buckler, preserving the posterior spine of the glabella. 1 e. Fragments of the cephalic border, showing a variable number of rows of punctures in front ; one having five, with seven or eight at the posterior margin. I f. A portion of the marginal fillet, where the crust is partially removed, showing the little studs or points which fill these pores from below. 1 g. A fragment of a large buckler, having but two distinct rows of punctures in front of the glabella. 1 h. A portion of the thorax and caudal extremity, from the glazed slate at Waterford. Fig. 2. 310. 1. Olenus asaphoides. (Pag- 256.) 3 a. An imperfect cephalic shield, with several articulations. 2 b. A smaller imperfect cephalic shield. 2 c. A fragment of one of the lateral articulations of the thorax. Fig. 3. 311. 2. Olenus undttlostriatus. (Pag. 258.) 3 a. The fragment, natural size. 3 4. A part of tlie same enlarged, showing the course of the facial suture, and the rugose striated glabella. Fig. 4. 297. 2. Calymene beckii. (Pag. 250.) 4 a. The buckler, with a lew of the articulations of the thorax. The specimen is very much compressed, and the crust removed. 4 6. A specimen of the same fossil, presenting nearly the entire length of the individual. 4 e. An impression of "the body, showing the indentations produced by the short spines upon the back. 4 d. A portion of the same enlarged, showing the impressions of the fine granulations of the crust. 4 f. A fragment preserving an impression of a part of the central and one lateral lobe of this species. Fig. 5. 312. 1. Agnostits lobatus. (Pag. 258.) 5 a, b. Individuals of the natural size. .') c, d. The same magnified. 5e,f. Specimens showing an articulation of the lobes. Magnified views. Fig. 6. 313. 1. Thaleops (lLL.a:Nns) ovatus. (Pag. 259.) 6 a. The specimen of the natural size. The upper figure has a strong thick spine at the posterior angles of the cephalic shield. I'l b. A part of the cephalic shield magnified, showing the punctures and the course of the facial suture. ( T U 1 L O B I T E S ) I'l 87 w :?# •'■?^. /* T Z,/ / / \ m Sil / » ^\ 5/Xj- • ) 3» ^ I Radr*T.-il7-J:l" ja-s- .v.- ;.■-! ) .it fOR»> PLATE 69. Fig. 1. 317. 5. BuTHOTREPHis? FLExuosA. ( Pag. 263.) i «. A large li'agment, with numerous branches or leaves. Tlie plant appears to have been long macerated before it was imbedded. 1 A. A specimen in the same condition as the last, with the branches less diverging. 1 c. A fragment of stone, with two smaller specimens retaining more of the original substance of the plant. lETDriDgOS!^ ISE'xfiilE iSl^>o:)Wl? I'l l(!i f \ r 1. A N 1- s ^^: -■- \i^ ■^ N STONK Br F SAINTON LITH OF a fcW EHDICOTT N.YORK. PLATE 69 A. Fig. 1. 317. 5. BuTHOTREPHis flexuosa. (Pag. 263.) A fragment of slate from Greenwich in Washington county, with a nearly entire specimen of this plant, which presents some slight differences from the preceding one. Specimens of the same species have recently been obtained from the unaltered slates of the Hudson-river group in Lewis county. xcim© a 'O iT m3!:^r]B3£i. ou'i'O to '^ V I. A N I' S I /if///ft /ry/'///s /7f:iff''.\'' PLATE 70. Fitr. 1 318. 5. PaL/EOPHYCUS VIEGATUS. (I'clg. ^63.) Fitr. 2. 319. 6. PaljEOphycus (Species undetermined). (Pag. 264.) ifri3;!.ce®yj rf\Tcy.^;35t (e!'::j\®'ii)n?',. I'l. A N IN $ m m ■iVfff:'-: ^"'%. \ t H ENOlCOTT LIT- r, voflr ■ii/.lM PLATE 71. Fig- 1 a, h. 320. 1. GORDIA MARINA. (Pag. 264.) !$nbJ IB) ^^® K" '}&.)l\Ti0,)^i ^13 JR C© W 5P „ 1*1 -I ON .STONR RY SWINTON. LITB OK G !. W, ENDICOTT N.YOS' II). vi;.-,,*:!!.!.. •. . (-.: •-■<■ PLATE 72. Fig. 1. 321. 2. Graptolithus pristis. (Pag. 265.) i a. A fragment of arenaceous slate from the Hudson-river group at Turin, preserving the base of several specimens. I 6. A portion of the same magnified. I c. A magnified fragment of the same species on the opposite side of this specimen, showing obtuse serratures. 1 rf. A specimen of the same species from tlie black slate of Oxtungo creek, south of Fortplain, 1 ^. A magnified portion of the same. 1 y. A fragment of the same species from the olive slate of the Hudson-river group at Loraine. 1 g. The same magnified, showing the obtuse termination of the teeth. 1 A. A specimen from the olive slate in Lewis county. 1 i. A magnified portion of the same. 1 ft. A narrow and somewhat more finely serrated specimen from the Utica slate. 1 /. The same magnified. I m. A small specimen, showing the axis extending beyond the serrated portion in both directions. 1 n. The same magnified. 1 o. A fragment of the same ffom the black slate of the Hudson-river group near Albany. I p. A magnified portion of the same, showing the acute teeth near the base, and the broader obtuse ones above. 1 r. This specimen resembles G.foliaceus of Murchison, and difiers slightly from the preceding in the short mucronate points of the teeth shown in the magnified portion I s : in other respects it is similar. Fig. 2. 322. 3. Graptolithus secalinus. (Pag- 267.) a a. A portion of the surface of a lamina of the Hoosick slate, with specimens of this fossil presenting some variations in character. The broader one crossing the figure has the form and appearance of Prionottis folium of HisiNGER ; but it is evidently only a more extenuated form of the same species as the more elongated and narrower ones. 2 It, b. Fragments of the slate from Baker's falls, with forms intermediate between the more expanded varieties of G. jwistis and those from Hoosick. 2 <•. A specimen from Hudson, where the slates arc partially metamorpliic, but much less thinly laminated, and the fossils less expanded, than those at Baker's falls or at Hoosick. •|U'3C.''£iDJi. ^^)rjA^t'3« &lfi£W3n?;.I1^X)f n^ll'r^^m ^JaC'tO"]^ O H A r I i> I. 1 T K S ) ■"A '-Vi ':i fA \ VA V^ tp m ^ J J r: ■J tn^,r«rBtl b> J t C PLATE 73. Fig. 1. 323. 4. Graptolithus muckonatus. (Pag. 268.) 1 a. Two fiagments of this species. I b. A portion of one enlarged. 1 c, (I. Fragments of the same species, one of them much contracted, and both preserving extremely mucro- nate teeth. Fig. 2. 324. 5. Graptolithus bicornis. (Pag. 268.) 2 a. A small specimen of the natural size, showing the bifurcation below. 2 i. A portion of the same magnified, showing the form of the teeth. 2 c. A larger specimen having the same character, with a stronger bifurcation, which is thickened at the point of separation. 2 d. A portion magnified. 2 e. A specimen having similar obtuse teeth, with the base removed and the midrib projecting above. 2/. A fragment of slate, with several specimens preserving the peculiar radical termination; associated with G. ramosus. 2 g, h. Magnified portions of these, showing a dissimilar form in the teeth. 2 i. A fragmeiit in the slate, preserving its original form in a good degree. 2 k. The same enlarged. 2 I. A fragment in limestone. 2 I'. A more compressed form in the same. 2m,m'. Enlarged portions of the same. 2 m". A magnified view of the edge of a specimen in limestone, showing an appearance analogous to G. sca- laris. 2 n. Transverse sections of the same magnified. 2 o. A slender specimen, with the sides parallel. 2 p. A similar specimen, preserving the capillary axis beyond the remaining portion of the stipe. 2 r, s. Magnified portions of these, showing their identity with the preceding. Fig. 3. 325. 6. Graptolithus ramosus. (Pag. 270.) 3 a, a'. Small specimens near the radical termination, having a simple bifurcation above. 3 b. A specimen with a more diverging and elongated bifurcation, with a smaller specimen lying obliquely across the right ramus. 3 ft' & b". The same species. 3 c, d. Enlarged portions of the two last. 3 e. A specimen with elongated rami, which are serrated on one side only. Fragments of G. Sagittarius on the same specimen. 3/. A specimen branched below, and bifurcating above. The branches and bifurcate stipe above are serrated on one side only ; while the stipe below and between the brandies and bifurcation is serrated on both sides. 3 e, h. Enlarged portions, showing the character of the teeth at the points of divergence, below and upon the branches. Fiir. 4. 326. 7. Graptolithus scalaris. (Pag. 271.) 4 a. A specimen showing the radical termination. 4 ft. A portion of the same magnified. 4 e. A more slender and tapering specimen, with a single range of dissepiments. - 4 rf. Magnified portion. 4 e,/. A small fragment, with oblique dissepiments and smooth margin. 4 g. A specimen with apparently a single range of dissepiments, and a central capillary axis projecting beyond the stipe. icr*3fii:t£ii;t. 4rf:c3AVJt'j« a isctetdd =y ^oss" ''m.'X'-y:s^:z* EviK-urcfip I: A 1- 'J- n 1. I 'I- K s ( PLATE 74. Fis. J. 327. 8. Graptolithus Sagittarius. (Pag. 272.) 1 a. A fragmenl of tlie slate, showing three nearly parallel stipes of this species. 1 6. A magnified portion, showing the upper margin of the teeth to be nearly rectangular to the direction of the stipe, while the lower side is oblique. Fig. 2. 328. 9. Graptolithus tejmuis. (Pag- 272.) 2 a. Slender elongated stipes of this species, associated with G. Sagittarius. ■J b. A portion of one of these magnified. ■J (.'. A small filiform stijie, gradually tapering and bent abruptly backwards. 2 d. A portion of the same magnified, showing the serratures ol the same character as the jirecedmg. Fig. 3. 329. 10. Graptolithus sextans. (Pag. 273.) 3 a. A fragment of slate on which are two specimens of this species, with straight diverging branches, 3 6. A portion of one of tliese magnified, showing the mucronate teeth, 3 c. Specimen with larger branches, 3 d, d. Two specimens, showing the appendages at the base. 3 e. One of the last magnified. Fig. 4. 330. 11. Graptolithos fukcatus. (Pag. 273.) 4 a. All individual on the same stone willi 3 d, showing tlie dift'erence in form. 4 h. Magnified portion. 4 c. A small specimen, with the branches more converging than usual. 4 d. A portion of the last magnified, showing no serratures on the inside of the branches. 4 e. Another specimen, similar in form to 4 c. if. A part of the same magnified, showing serratures on the inside of the branches. 4 g. A specimen with elongated branches which cross each other. • 4 A. A part of the same magnified, showing both margins to be serrated. Fig. 5. 331. 12. Graptolithus serratulus. (Pag- 274.) 5 a. A specimen of the natural size, diverging from a slender smooth spine or mucronate radicle below, •5 b. A portion magnified, showing the form and opposite direction of the serratures at the base. Fig. 6. 332. 13. Graptolithus gracilis. (Pag- 274.) 6 a, b. Two specimens (natural size), showing the principal stipe and branches, one of the latter being sub- divided. li c. A specimen in which the principal stipe is obscure : several branches are subdivided. A fragmenl ol (i. prislis, and of G. mucronattcs, are shown on the same piece of slate. 6 d. A fragment magnified, showing the serratures of the branches. Fig. 7. 333. 14. Graptolithus? l^vis. (Pag. 274.) Fig. 8, 381. 15. Graptolituus arundinaceus. 8, The specimen, natural size. S a. The same magnified i c, H A I' r u r, [ •(• K s 1 ;iar^WJ E &«nt % \ 4. PLATE 76. Fig. 1. 334. L Favistella stellata. (Pag. 275.) 1 «. A fragment ol this coral, showing a vertical section, with an oblique section of the extremities of the tubes. 1 i. A transverse section of the cells, showing the starlike extremities. 1 c. An enlarged view of the extremities of several cells. Fig. 2. 101. 2. Ch^etetes lycoperdon. (Pag. 276.) 2 a, b. The bases of two hemispherical forms, where the tubes have a barely perceptible extension. 2 c. A fragment of a ramose form, one of the largest occurring. in this group. 2 d. A subhemispheric form, which commenced its growth upon the column of a crinoid. 2 e. A fragment of stone, with several ramose forms associated with a crinoidal column, a small Murchuonia and Orthis testudinaria. 2/. Magnified section of a ramose form, showing the columns to be nearly parallel to the axis of the specimen. Fig. 3. 335. 1. DiscoPHYLLTJM peltatitm. (Pag. 277.) Fig. 4. 336. 1. {U7tdetermi7ied.) (Pag. 277.) t Ih f CORALS. ) v PI . J> i^=^i?^ » '*• ^ !• V * V: i. :'a'^ .'r/ ^ i- V So. :^ .^^ '■* * nJV STONK BY F. SWfNTtJN. t.lTH OF M R PlJtllNSON' N Y»^ 0 w m. ivrm '.a. '& :y. o ^>■l" :;':' I (■ u I s I <) i> !■; -^ y" On ^ O^ O H _- f 0 '" n '.••/ an V 5' PLATE 77. FicT. 1. 340. 1. Glyptocrinus decadactylus. (P^g- 281.) 1 a. A fragment of stone with two small specimens, preserving the tentaculated iingers. 1 b. Figure of a larger specimen, showing the character of the plates and their arrangement more distinctly. 1 c. The upper extremity or crown of the last specimen, showing the capital plates. 1 d. Same enlarged. 1 e. A portion of the surface enlarged, showing the form and diaracter of the plates, and the strong radiating ridges. I/. An enlarged figure, showing the structure and arrangement of the plates as described (pag. 2S4, note). M'iriDiSosa" T£air'>y:ffi:i£i £i2E.t)'j:r]i^ I'l 77 (c R INIOD fJJ S Jii "^ vi ^ ^ @ ® ® ..'^^ V ai v' --/^ .^ / o %(/ f J DsarabrSMHaa -^rf-r-iSr >»^' fcl-'i:e -.I. PLATE 78. Fig. 1. • 340. 1. Glyptocrinus decadactylus. (Pag. 281.) 1 a. A figure of a specimen, preserving a small portion of the column and the entire length of the fingers. 1 b. Fragments of columns, composed of alternating large and smaller discs with angular edges. 1 c. Section of the same. 1 d. Section and figure of a similar fragment of a column enclosed in a coral. 1 e. Fragment and section of a column where the discs are excavated on their upper side, and have plain rounded edges with a pentapetalous impression on the extremities. 1 f. Fragment of similar character, having the upper edges of the plates fimbriated. 1 g. Section of the same enlarged. 1 h. Magnified portion, showing the fimbriated edges of the discs. \ i. Separate plates or discs of a similar column, showing the variable character of the marginal crenulations, one specimen being marked by six prominent angles. 1 k. Two figures, showing tlie proportionate size of the larger and smaller discs in the columns, composed of plain alternating joints. 1 n. Fragment of a column, with the edges of tlio discs rounded and slightly nodulose : intermediate plates thin. 1 0. Edges of the discs rounded and nodulose ; intermediate ones thin, nodulose. 1 p. Edges of the discs rounded and smooth, the intermediate ones tliin. 1 r. Edges of the discs flat and broad, the intermediate ones thin. I s. A fragment of slate with moniliform columns ; the intermediate plates often being scarcely distinct, while in others they are half as thick as the larger ones. 1 t. Large fragments of columns in the compact slaty rocks of the Hudson-river group, with the discs thick, the intermediate ones being scarcely visible, 1 u. A similar fragment of a column, with a section of the end, showing identity with the preceding figures. Fig. 2. 129. 1. Tentaculites flexuosa. (Pag. 284.) 2 a. Fragment of stone with several specimens a, a, a, associated with corals, shells, etc. 2 6. A specimen enlarged, showing the longitudinal stris. I it o s ^ © 3£fj:a-3D)S'OW :E.a:^r:ffi:ai. e-jRO-ir^i' <; H I N o r ij I'. A J I t *^.MJI L*'4i»Gant kXfufk.* 'Ig. PLATE 79. 1. 133. 7. LiNGULA QUADRATA. (Pag. 285.) 1 a, b. Figures of two specimens, showing the difference ordinarily seen in the form of this fossil. 1 c. A portion of the surface magnified. Fig. 2. 141. 4. Leptjena alternata. (Pag- 286.) 2 a. Mould of the interior of the convex valve of this species, showing the form of the visceral impression, the oblique teeth, etc. The nasute character is well preserved. 2 b. Figure of a similar specimen, where the nasute cliaracter is less conspicuous. 2 c. A smaller specimen of the same character, showing a slight contraction in front. 2 d. A portion of the surface of one of these enlai-ged, showing the striato-punctate character. 2y. The impression made by the outside of the convex valve of this species, showing the fascicles of striae in a perfect manner. 2f*. A cast of a large symmetrical specimen, showing the same characters of the surface, form of visceral impression, etc. 2 g. A small specimen, preserving the shell, and showing the stria? in interrupted fascicles. 2 g\. A portion of the surface enlarged. 2 h, i. Figures of specimens which still preserve a part of the shell, having the stria; in broad fascicles of small ones separated by larger ones. 2 k. Interior of the ventral valve, showing two small teeth on the hinge line, with three diverging callosities. 2 /. Mould of the interior of the ventral valve, showing the two cavities made by the teeth, and tile impressions of the radiating callosities. Fig. 3. 146. 9. LEPTiENA sEEicEA. ( Pag. 287.) 3 a. A mould of the interior of the shell. 3 b. An enlarged portion, showing the striato-punctate character of the surface. 3 a*. Another specimen, presenting more distinctly the usual character of casts of this species. Fig. 4. 155. 2. Orthis testudinaria. (Pag- 288.) '1 a, b. Casts of tiie interior of the dorsal valve. 4 c. Cast of the interior of the ventral valve. A d. A similar cast, more strongly impressed by the striae. 4 e. A fragment of the impression of the outer side of the ventral valve, showing the fine concentric strise, which crenulate the diverging striae. Fig. 5. 341. 19. Orthis EERATicA. (Pag. 288.) 5 a, b. Dorsal and ventral views of the cast of a large specimen. 5 d. Ventral view of a small specimen. 3 c. Front view of a larger specimen. 5 e. Cardinal view of a large specimen. 5f. Profile view of a moderately convex specimen. Fig. 5*. 342. 20. Orthis centrilineata. (Pag. 289.) .5 a*. A specimen, natural size. 5 6*. Magnified portion of the cardinal line and visceral impression. 5 c*. Several striae enlarged, showing the bifid and trifid character. Fig. 6. 186. 19. Atrypa increbescens. (Pag. 289.) Fig. 7. 343. 5. Oebicula? subteuncata. (Pag. 290.) 7 a. A small fragment with several individuals upon the surface. 7 S. A single specimen enlarged. Fig. 8o. 344. 6. Oebicula? ceassa. (Pag. 290.) Fig. 9. 345. 7. Oebicula cjelata. (Pag. 290.) 9 a. An imperfect specimen. '.> b. The same enlarged, to show the central depression and lateral plications. 9 c. A portion of the surface still farther enlarged, showing the character and arrangement of the papillae. ( B R ACHXO P O D A. j m 79 1 i I- r '.■:i % -^ V' r ^Wr s, '^'9titii]w' ^ /v" H* mm w. T^i ■4. a. Y> \ 1 D \. 9 SJ 7^. 1^1 9a, 9 a VnKwn iy S M II lLB^««dk7 C**ii*&«ikt« .Iv'Jili.lil" ^ / ^.v>;v ■V;>'-''K) { i'St .::'.'-'■) ,j . k .■■..■ -t *v;.';' 'i ,!■'/ PLATE 80. Fig. 1. 346. 3. AvicuLA insueta. (Pag. 291.) 1 a. A specimen, natural size. 1 b. A portion of the surlace enlarged. Fig. 2. 347. 4. AvicuLA DEMissA. (Pag. 292.) 2 a. A large perfect specimen, which is more elevated than usual. 2 b. The impression of a sm:Jler specimen in sandstone. Fig. 3. 348. 5. AvicuLA? DESQUAMATA. (Pag. 292.) 3 a. A specimen, natural size. 3 b. An enlarged portion of the surface. Fig. 4. 349. 7. Ambonychia radiata. (P^g- 292.) 4 a, b. The right and left valves of different specimens of this species. 4 c. A smaller individual, with the radii distinctly marked, and more than thirty in number. 4 d. A young specimen, with the radii finely marked. 4 c. A portion of the surface enlarged. 4/. A cast of the interior of the right valve : the posterior slope shows a straight, well defined, impressed line. 4 h. Profile view of a specimen preserving both valves. 4 i. Lateral view of the same. The difference in form between this and the preceding specimens is due to pressure. 4 ;'. A large specimen incrusted at its base with a coral, of which an enlarged portion is given in 4 g. ( The letter is omitted on some of the plates.) 4 k. Enlarged portion of the surface, showing the same structure as 4 e. 4 /. An impression of a part of the valve of a very large and strongly ribbed specimen. Fig. 5. 350. 8. Ambonychia carinata. (Pag. 294.) 5 a. Left valve of this species. 5 h. Profile view, showing both valves. The apparent inequality of the beaks is produced by a slight displace- ment from pressure. i^TD/iD)ig(D)K>/ ii.>j(.\w]t:m iigjsUDiw; n 8 0 ,.. ) .:'^^^S!^^r>^'l ^*3f^ •Vl% 1.* J '■'' .11 f H ■' ;•. ;4 w I NTow , n fc V,-, EHOicoTT i.:th ;;.vor.k PLATE 81. Fig. 1. 351. 11. MODIOLOPSIS MODIOLARIS. (Pag. 294.) 1 a. A specimen preserving the two valves in connection, showing the hinge-line, and the anterior muscular impression, which produces an elevation upon the outer surface of the shell. ' 1 b. Another specimen preserving the two valves, which are latei-ally compressed. The anterior extremities are narrowed, and somewhat obtusely pointed. 1 c. A single valve, with the posterior extremity more regularly rounded, and tlie hinge-line curved. 1 rf. A smaller and shorter specimen, with the base not contracted or arched. 1 €. A small specimen, contracted at the anterior, and expanded towards the posterior extremity. The base is arched, and the hinge-line apparently curved. ly. A specimen from the shales at Madison (Indiana), preserving both valves. 1 g. The anterior extremity of a cast of this species, showing the prominence of the muscular impression. Fig. 2. 203. 4. MoDioLOPSis nasutus. (Pag. 296.) Fig. 3. 352. 12. MoDioLOPsis truncatus. (Pag. 296.) 3 a. View of the right valve of this species. 3 b. Profile view, one valve being more compressed than the other. Fig. 4. 353. 13. Mobiolopsis ctjrta. (Pag. 297.) A large individual of this species, from near Grimsby, Canada West. Fig. 5. 354. 14. M.omoh07Bis (Species undetermined). (Pag. 297.) 5 a. Left valve of the fragment. 5 6. Dorsal view of the same. (This species is erroneously marked 4 a, b, on some of the plates.) isjwaisitoss mnwigiii (^mimi^if^n PI «t A C E f II A 1, A /IS^S:^ ^^ J \s!-r^< ¥ -N aiDNE BY F- SWINTON. 0 t W EKLIPOTT UTfl. N.YnftK ^^.i^:•; ."F I \ ■ 'W' .'"t" ,: f ''1 I!;: ■ . ! 1 PLATE 82. Ficr. 1. 351. 11. MoDioLOPsis MODioLARis. (Pag. 294.) A young specimen of this species. Fig. 2. 353. 13. Modiolopsis curta. (Pag. 297.) 2 a. A sjiecimen from Loraine, Jefferson cnuntv, New-Yovk. 2 4. A small specimen in sliale, from Rodman, Jeffei-son county. 2 c. Figure of a small specimen from Mineral Point, Wisconsin. 2 d. Cardinal view of the same species. Fio-. 3. 355. 15. Modiolopsis anodontoides. ( Pag. 298.) 3 a. A specimen in sandstone, preserving the original form of tlie shell. 3 6. A specimen in soft shale, more compressed than the preceding, and consequently rounded at the posterior extremity. 3 c. A si>ecimen in shale, where both valves are still adhering. Fig, 4. 202. 3. Modiolopsis FABA. (Pag. 298.) -I a, b. Views of two specimens — casts in sandstone. Fig. 5. 356. 16. Modiolopsis ? NuctTLTFOKMis. Pag. 298.) 5 a. Specimen preserving both valves. 5 b. A right valve, less compressed than the preceding. Fig. 6. 357. 1. Oethonota pholadis. (Pag. 299.) Fig. 7. 358. 2. Oethonota parallela. (Pag. 299.) 7 a. The left side of a cast scarcely retaining any markings. 7 il. Dorsal view of the same. 7 b. Dorsal view of a cast in coarse sandstone, where the folds are visible on the dorsal margin. 7 e. The left valve, preserving the shell, which is finely striated concentrically, and sliows the folds upon the cardinal line. Fig. 8. 359. 3. Oethonota contracta. (Pag. 300.) 8 a. The left valve, showing the distinct carina and concentric striae of the surface. 8 b. Dorsal view of the same, showing the oblique wrinkles on the posterior cardinal margin of the shell. Fig. 9. 360. 1. Cleidophorits planulatus. (Pag. 300.) 9 a. Specimen of arenaceous slate, with several individuals of this species, associated with crinoidal columns. 9 b, c, d. Other individuals from ditierent localities, showing a slight difference in form. 9 e. A specimen from the altered slates, preserving both valves. Fig. 10. 190. 2. Nucula? poststruta. (Pag. 301.) 10 a. A small specimen in the ferruginous sandstone. 10 b. A larger specimen, preserving very distinctly the strise on the posterior slope. Fig. 11. 361. 1. Lyrodesma plana. (Pag. 302.) 11 a. The right valve. 11 b. Interior of the same, showing the cardinal teeth. Fig. 12. 362. 2. Lyrodesma pitlchella. (Pag. 302.) 12 a. A specimen of the natural size, from the black slate near Watertown, Jefferson county. 12 6. The same eiilareed, showing the character of the crenulations. 12 c. A smaller specimen from tlie partially altered slates near Waterford on the Hudson rivei'. 12 d. The cardinal line enlarged. ]ETDriE)'3'£)X>r miCT^filSi &:ti.U'.iyi£'. ( AlK I'H.M.A I Q ^> S?^-^ ^ /^ /.^■- 'trrrrrrfwrwrti >*.- .4/. "^_ o G© .r>^ r ^ ) ^.#! >^^"^^^ «^t I® y ' r-^ V III, 4s- \ _. ItJ STONC BY r. SiVINTON G- ft « CNOiCOT ' L"n ^ 'Ofli. .... 1 ; :_ 1 I .'■ :r _,.-'ii ■) ■. 1,11.-' ->ii PLATE 84. Fig. 1. 369. 4. Cyrtolites oknatus. (P^g- 308.) 1 a. Liitural view of a cast of this species. 1 h. Piufile of the yame, looking into tlie aperture. 1 c. Another specimen (a cast), where the volutions are contiguous. 1 rf. A specimen preserving the shell, from which the finer stria; are removed. 1 e. A portion of the surface of the shell, showing the sculpture. \ f. Part of the same magnifieil. 1 g. A transverse section of the shell. Fig. 2. 249. 1. Teocholites ammonius. (Pag- 309.) 2 a. A small specimen, partially preserving the shell in some parts, and showing the sejjta in others. 2 b. An enlarged portion of the surface, which is partially exfoliated, and slightly difierent from similar mag- nifed parts of those in the Trenton limestone, where the shell is well preserved. 2 c. Mould of a large specimen in the black slate. Fig. 3. 370. 2. Trocholites planorbiformis. (Pag- 310.) 3 a. Figure of a specimen nearly entire. 3 ft. Dorsal view of the same. 3 c. Ventral view of a fragment, preserving part of the two outer volutions, showing the concave ventral side, and the position of the siphuncle. 3 c*. Section of the outer volution. 3 d. A portion of the surface magnified. 3 e. A specimen crushed in a vertical direction, a part of the outer volution retaining its form. 3/. Dorsal view of the same, showing the slightly arching septa upon the dorsal line, and a part of the outer chamber. WifnfSA. SIl,A'J?g AXSSJiiJ lEWSSSSS JauVrSiiU!. m&www. I' I HI lGAN-rri»roDA ami I'KrilALOroDA / y ^• v M J A ■tWJIjIW ' .'? K i'!l' .^S^. '^' 5£j ^>--''''^' 5^ ° r I H '> (iKTuorKi: A I' A 1 / • .^ \ 'U'i u ' iil'H lt^■ fi »• * K.NIl'OO'' • {.erf; .^,iiT i '.-;JH.;, 'I PLATE 86. Fig. ]. 373. 27. Okthoceras coralliferum. (Pag- 312.) 1 a. A small fragment from the altered shales near Waterford, Saratoga county. The septa are represented too distant in the figure. A portion of the coral covering the surface is magnified in 1 b. 1 c. A fragment from tlie green shales of Lewis county. 1 d. A fragment from the sandstone of the Hudson-river grou]>. Fig. 2. 374. 28. Okthoceras lamellosum, (Pag. 312.) •J b, c. Fragments near the smaller extremity ; the septa being indistinctly preserved. 2 d. A fragment showing the comparative distance of the septa, in which it varies slightly from 2 c. 2 e. Section of the last, showing the position of the siphuncle. Fig. 2 a. 375. 2. Ormoceras crebriseptum. (Pag. 313.) A fragment of this species, the siphuncle being distinctly moniliforin. swagossr a2wi§ra. @riae]-j'3>c fi a I) OnTHOCKHATA . m / /J ,-m^^^ r-T^Mi m^. •^^»>.^p_<«_i r \^ 0 2 d ON 3T0NE BY F. SWINTOM . a & Vi-. ZHDIOOIT LITK. N. YORF. PLATE 87. Fig. I. 376. 1. Theca? TRiANGULAEis. (Pag. 313.) I a. A portion of a large specimen, with tlie smaller extremity broken off. 1 e. Section of the same. 1 4. A smaller specimen, very perfectly terminated at both extremities. 1 " .^TOHE BT F JSWiNTOM. a 8- W. EN3U-orT iirH M YOR.K. ,1; m'' .0 ■*'""' PLATE 33*. Fig. 1. 175. 8. Atkypa cuspidata. (Pag. 138.) 1 a. Ventral valve of a perfect specimen. 1 b. Front view. 1 c. Dorsal valve. 1 d. Profile view. \ e. Front view of a specimen, where tlie sinus is narrower and more angnlar than in the preceding. 1 f. Profile view of the same. 1 g. Dorsal valve of a specimen which is more extended laterally. 1 li. Front view of tlie same. Fig. 2 a, h. 377. 8. Ambon ychia mytiloides. (Pag. 315.) Fig. 3. 379. 3. NucuLA? DONAciFOEMis. (Pag. 316.) 3 a. Right valve of this species. 3 b. Cardinal view of the same. Fig. 4. 380. 6. BucANiA intexta. (Pag. 317.) 4 a. Dorsal view of the fragment. 4 b. Lateral view. 4 c. A portion of the surface magnified. 4 d. A portion of the surface of B. sulcatina magnified. Fig. 5. 354. 14. Modiolopsis terminalis. (Pag. 318.) 3 a. Left valve of the fragment. 5 b. Dorsal view of the same. s-.£U.a-jr»ii'anBssf'ii'(C!^& rei'jjnfcBDjfl' jstxTJUisi ( 5f [ S C K f. f. A. X K o l; a; t r I Li' ^ ■J 6 0 « » a^kir^*' tTT»to2 hy'^illlIrvLSl' BINDING SECT. JUL 1 0 1969 QH Natural history of New York 105 N7N3 V.18 Biological & Medica' PLEASE DO NOT REMOVE CARDS OR SLIPS FROM THIS POCKET UNIVERSITY OF TORONTO LIBRARY ' , ; 1 ■! '■''■ ':■ '' ''■'i"'ii'.: