CATALOGUE OF THE BLASTOIDEA IN THE GEOLOGICAL DEPARTMENT OF THE BRITISH MUSEUM (NATURAL HISTORY), WITH AN ACCOUNT OF THE MORPHOLOGY AND SYSTEMATIC POSITION OF THE GROUP, AND A REVISION OF THE GENERA AND SPECIES. (ILLUSTRATED BY 20 LITHOGRAPHIC PLATES, &c.) BY ROBERT ETHERIDGE, JUN., OF THE DEPARTMENT OF GEOLOGY, BRITISH MUSEUM (NATURAL HISTORY), AND P. HERBERT CARPENTER, D.Sc., F.R.S., F.L.S. (OF ETON COLLEGE). PRINTED BY ORDER OF THE TRUSTEES. 1886. ' 1J.AMVW. PRINTED BY TAYLOR AXI> FRANCIS. RED UON COURT, FLEET STREKT. f S/) PREFACE. WHEN the Authors of the present work commenced their task of monographing this curious and extinct group of Echinodermata, they did not contemplate the production of an official publication, but a Memoir on the Blastoidea to be presented to one of the learned Societies. As their illustrations had, however, been largely taken from specimens in the British Museum, it was suggested that the work should be submitted to the Trustees to appear as one of the series of Museum Catalogues. At this time sixteen of the twenty Plates illustrating the work had already been drawn upon stone and paid for out of the Government Grant Fund of the Royal Society. These Plates were, however, with the approval of the Council, transferred to the Trustees, at whose cost they have been printed off, and also four additional Plates drawn and added to the series, together with seven illustrative woodcuts. Science is greatly indebted to the Authors for their very careful and patient labours, not only in the study and comparison of external forms both of recent and fossil Echinodermata, but in preparing sections showing the internal structure of these organisms, involving long and patient examination with the microscope, by means of which they have been largely assisted in working out the morphology of this obscure and but little understood group. HENRY WOODWARD, Keeper of the Department of Geology. BRITISH MTJSETTM (NATURAL HISTORY), JULY IST, 1886. AUTHORS' PREFACE. THE present work is the result of our joint study of the Blastoidea, which has been carried on for the past seven years, though with a considerable amount of interruption owing to our official duties and to the pressure of other engagements. It originated in a strong desire to investigate the structure and relationships of this interesting group of extinct Echinoderms by the light of the recent advances in our knowledge of their living representatives. The additions to our knowledge of Echinoderm structure which we owe to the genius of Johannes Miiller no doubt largely influenced Professor Ferdinand Roemer when preparing his classical work on the Blastoidea, which is now more than thirty- five years old, and must be regarded by all as a model of precise and accurate descrip- tive Palaeontology. But recent discoveries have furnished so much additional information as to the relationships of the Stalked Echinoderms, that they are now viewed in quite a different light from that which was shed upon them by Miiller's memorable researches. Under these circumstances, the interest attached to a renewed morphological investigation of the Blastoidea attracted us very strongly. Our chief difficulty, the want of adequate material, was soon and simply solved ; for Mr. Charles Wachsmuth, of Burlington, Iowa, whose admirable work on the Palaeocrinoids is known to every palaeontologist, generously offered to place at our disposal a selected series from his fine collection of American Blastoids, which should be specially adapted for the exhibition of structural characters. The collection reached us in April, 1881 ; and though it was originally lent for six months only, the owner's liberality has enabled it to remain in our hands for over five years. Nothing that we can say can express better than this statement the extent of our indebtedness to Mr. Wachsmuth's generosity, which prompted him to expose a valuable collection to a double journey across the Atlantic and a prolonged detention in this country, in the hope of promoting scientific knowledge. We wish that we could regard the results of our work as at all commensurate with our feeling of indebtedness to Mr. Wachsmuth, with whom we are sorry to find our- selves at variance upon certain morphological questions. But it is perhaps scarcely vni PEEFACE. to be expected that there should be a complete concordance of opinion between workers who approach the subject from altogether different sides ; and the discovery of the truth, which is the ultimate object of us all, can only be attained by a com- bined investigation along several converging lines of inquiry. Besides providing us with material, Mr. Wachsmuth has also been kind enough to keep us informed from time to time of the progress of his own researches, and in some instances these have led to the abandonment or modification of views which we had previously expressed. Thus, for example, we did not become fully aware until the end of last year that the Silurian Troostocrmus Eeinwardti must be separated generi- cally from most of the Carboniferous species usually referred to this genus ; and it was not till March last that we learnt of Mr. Wachsmuth 's most important discovery that Stephanocrinus is not a Blastoid at all, but a Brachiate Crinoid. The earlier sheets of this work, therefore, contain many passages which would have been dif- ferently expressed had we known as much when they were written as we do now. But we are indebted to Mr. Wachsmuth's kindness for the opportunity of modifying our earlier statements in the later portion of the Catalogue, and we can now only tender him our most sincere thanks for the very free use which he has allowed us to make of his unpublished observations. (See pp. 118, 196.) We have also to express our gratitude to the many other scientific friends, both at home and abroad, for the ready way in which they have facilitated our work, either by the gift, exchange, or loan of specimens, or by valuable information of various kinds. We would mention especially Professor W. H. Barris, of Davenport, Iowa ; Mr. R. R. Rowley, of Curryville, Missouri ; Professor A. H. Worthen, of Springfield, Illinois ; Messrs. S. A. Miller and A. G. Wetherby, of Cincinnati ; and Mr. E. N. S. Ringueberg, of Lockport. Don Lucas Mallada, of Madrid ; Professors L. G. de Koninck and G. Dewalque, of Liege ; Prof. F. Roemer, of Breslau ; M. Munier- Chalmas of Lille ; and Professors Albert Gaudry and E. Perrier, of Paris, have all been kind enough to supply us with valuable material ; and we have been similarly favoured nearer home by Dr. A. Geikie, Director-General of the Geological Survey of Great Britain ; Mr. J. Bennie, of Edinburgh ; Prof. H. A. Nicholson, of Aber- deen ; Prof. T. McKenny Hughes, of Cambridge ; Prof. W. J. Sollas and Mr. W. H. Baily, of Dublin ; Prof. W. Boyd Dawkins, of Manchester ; Dr. G. J. Hinde, of Mitcham ; Rev. G. Style, of Giggleswick ; Rev. G. F. Whidborne, of Torquay ; and Mr, D. Geddes, of Blackburn. All these gentlemen have responded to our inquiries with the most liberal kindness, and we therefore take this opportunity of expressing our thanks to them for their help. The material lent us by these gentlemen and from other sources has fur- nished 89 figures, in addition to the 72 figures drawn from Mr. Wachsmuth's collection ; while 178 specimens illustrated by 245 figures are in the National Collection. The latter contains representatives of all the nineteen genera of PEEFACE. ix Blastoidea, except the rare Pentephyllum and Eleutherocrinus, though the former type is illustrated by a cast of the only known specimen, which belongs to the Museum of the University of Dublin. As the National Collection also contains a good series of the American Blastoids, and numerous representatives of those found in France, Spain, Belgium, and Germany, together with the valuable collections made by Rofe and Gilbertson from the Carboniferous Limestone of Lancashire and Yorkshire, we have no hesitation in saying that it is not only unrivalled, but that it is not likely ever to be surpassed in the completeness of its collection of Blastoidea. For the localities where Rofe and Gilbertson obtained their specimens are no longer so pro- ductive as they were, and neither Blastoids nor Crinoids can now be procured so easily as was the case even up to twenty years ago. We have further specially to acknowledge the generous aid which has been afforded to us by the Council of the Royal Society, who placed at our disposal in 1881 a sum of money from the Government Grant Fund, to assist us in adequately illustrating our work ; we are also indebted to them for allowing the sixteen Plates which had been paid for out of that fund to be published in a volume issued by the Trustees of the British Museum. These Plates, together with the four which have been since drawn, are the work of our friends, Messrs. Charles Berjeau, F.L.S., and Percy Highley ; and we find it difficult to express our appreciation of the care and zeal with which they have performed a very important share of our joint work. The arrangement of the Plates has been necessitated by circumstances. The material which is now at our disposal was not all in our hands when the earlier Plates were drawn, but has reached us at intervals during the progress of our researches ; and the consequence is that the figures illustrating some specific forms are scattered over several Plates, instead of being concentrated on one or two, as they would have been had we been able to collect all our material before com- mencing our illustrations. We have endeavoured, so far as it has been in our power, to make the present work a monograph of all described Blastoidea ; but we have found ourselves obliged to leave it incomplete at many points. There are very few European Blastoids, pro- bably not half a dozen in all, which we have not studied ; and by the kindness of Mr. Wachsmuth and of other friends in America we have been enabled to examine one or more species of all the genera which occur in that country. But there are still many species about which little is known. In some cases this is due to the rarity of the literature concerning them, and in others to the want of adequate descriptions or figures. In many cases, too, we are in great uncertainty as to the stratigraphical position of a species, owing to a want of precision or of accurate geological infor- mation on the part of its describer. These are questions which can only be satisfac- torily solved on the spot, and we must therefore leave them in the hands of our b x PREFACE. American fellow-workers, in the hope that one of them will undertake a critical revision of the American species of Blastoidea. We would further express the hope, however, for the sake of our successors, that this work will not be attempted by any mere collector, however zealous, and no matter how many thousand specimens his cabinet may contain, but by a trained palaeontologist who is acquainted with the principles of morphology in general, and with that of the Echinoderms in particular. For we feel very strongly that unless systematic Palaeontology is based upon Morpho- logical principles its results are not likely to have any permanent value ; and we could wish that some of Roemer's successors had realized this fact as clearly as he did himself. R. ETHERIDGE, JUN. P. HERBERT CARPENTER. DEPAKTMENT OF GEOLOGY, BRITISH MTJSETTM (NATTJKAL HISTOET), JUNE, 1886. TABLE OF CONTENTS. MORPHOLOGY. Page CHAPTER I. THE ZOOLOGICAL HISTORY OF THE BLASTOIDEA 1 CHAPTER II. THE STEM AND CALYX 9 A. The Stem 9 B. The Calyx 10 C. The Basals 12 Dorsal and radial axes 13 Ridges on the basal cup 16 Supposed under-basals of Blastoids 18 D. The Radials 22 Homologies of the radials 26 E. The Deltoid Plates or Interradials 28 Deltoids of Heteroschisma 30 ,, Stephanocrinus 34 El&acrinus 35 Troostocrinus 36 F. On the Homologies of the Deltoid Plates 37 G. Irregularities of the Calyx, and Monstrosities 39 CHAPTER III. THE AMBULACRA 42 A. The Lancet-plate and its Internal Relations 42 Under lancet-plate 44 Lancet-canal 50 OEsophageal ring 52 B. The Superficial Markings of the Lancet-plate 54 C. The Side Plates 56 D. The Outer Side Plates 61 E. The Pinnules 63 F. The Covering Plates of the Ambulacra 63 b 2 xii TABLE OF CONTENTS. Page CHAPTER IV. THE SUMMIT-PLATES 66 Homologies of the Summit-Plates 71 CHAPTER V. THE HYDROSPIRES AND SPIRACLES 76 A. Historical 76 B. Descriptive 87 1. The Hydrospires 87 2. The Spiracles 96 CHAPTER VI. THE ZOOLOGICAL CHARACTERS OF THE BLASTOIDEA 113 Definition of the Pelmatozoa 117 Definition of the Blastoidea 117 Regulares. and Irregulares 122 Mutual relations of the Genera 125 DISTRIBUTION. CHAPTER VII. THE GEOLOGICAL AND GEOGRAPHICAL DISTRIBUTION OF THE BLASTOIDEA 129 Silurian forms 129 Devonian forms 129 Carboniferous forms 133 Table showing the Distribution of the Genera of the Blastoidea in Space and Time 136 A Stratigraphical List of all known Blastoids, arranged geographically 137 Species from the Upper Silurian 137 Species from the Devonian 137 Species from the Carboniferous Limestone 140 CLASSIFICATION. CHAPTER VIII. DESCRIPTIONS OF THE SPECIES 146 Synopsis of the Orders, Families, and Genera 146 Order Regulares 148 Family Pentremitidae 148 Definition of genus Pentremites 151 History of the genus 152 General characters 154 Pentremites Godoni, Defrance, sp 157 var. major, var. nov 160 \ar.florealis, Schlotheim, var. . . . 160 var. abbreviatus, Hambach, var. . . . 160 TABLE OF CONTENTS. xiii CHAPTER VIII. DESCRIPTIONS OF THE SPECIES (continued}. Pentremites elongatus, Shumard ....*.... 161 conoideus, Hall 162 sulcatus, Roemer 165 obesus, Lyon . 167 pyriformis, Say 167 Definition of genus Pentremitidea 169 General characters . . . . 170 Pentremitidea Paillettei, de Verneuil, sp 172 Lusitanica, E. & C 173 Eifelensis, Roemer, sp 174 Malladai, E. & C 175 clavata, Schultze, sp 176 var. Schultzei, E. & C., var. . . . 177 Wachsmuthi, sp. nov 178 Gilbertsoni, sp. nov . . 179 angulata, E. & C 180 similis, E. & C 180 Definition of genus Mesoblastus 181 General characters 182 Mesoblastus crenulatus, Roemer, sp 183 angulatus, G. B. Sowerby, sp 185 elongatus, Cumberland, sp 186 Sowerbii, sp. nov 187 Rofei, sp. nov 188 Family Troostoblastidse 190 Definition of genus Troostocrinus 191 General characters 192 Troostocrinus Reinwardti, Troost, sp 194 Definition of genus Metablastus . . , 196 General characters ..197 Metablastus lineatus, B. F. Shumard, sp 199 Hispanicus, E. & C 200 Cottaldi, Mun.-Chalmas, sp 201 Definition of genus Triccelocrinus 203 General characters 204 Tricoslocrinus obliquatus, Roemer, sp 206 Meekianus, sp. nov 208 Family Nucleoblastidse 209 Subfamily Elseacrinidse 210 Definition of genus Elaeacrinus 210 General characters . 212 xiv TABLE OF CONTENTS. Page CHAPTER VIII. DESCRIPTIONS OF THE SPECIES (continued). Elaeacrinus Verneuili, Roemer 216 var. pomum, var. nov 218 angularis, Lyon, sp 219 sp 219 Subfamily Schizoblastidse 220 Definition of genus Schizoblastus 220 General characters 221 Schizoblastus Sayi, Shumard, sp 224 melonoides, Meek and Worthen, sp. . . . 226 Rofei, E. & C 228 Definition of genus Cryptoblastus 229 General characters 230 Cryptoblastus melo, Owen and Shumard, sp 232 Definition of genus Acentrotremites 234 Acentrotremites ellipticus, Cumberland, sp 235 Family Granatoblastidse 237 Definition of genus Granatocrinus 238 General characters 240 Granatocrinus Norwoodi, Owen and Shumard, sp. . . . 245 orbicularis, G. B. Sowerby, sp 248 Derbiensis, G. B. Sowerby, sp 250 campanulatus, M'Coy, sp 251 M'Coyi, sp. nov 252 ellipticus, G. B. Sowerby, sp 253 Definition of genus Heteroblastus 255 Heteroblastus Cumberlandi, sp. nov 257 Family Codasteridae 257 Subfamily Phsenoschismidae 258 Definition of genus Cadaster 259 General characters 261 Cadaster pyramidatus, B. F. Shumard 266 trilobatus, IVTCoy 268 var. acutus, M'Coy, var 269 Definition of genus Phcenoschisma 270 General characters 271 Phaenoschisma Verneuili, E. & C 273 Archiaci, E. & C 274 nobile, E. & C 275 acutum, G. B. Sowerby, sp 276 caryophyllatum, de Koninck, sp. ... 277 Benniei, sp. nov 278 TABLE OF CONTENTS. xv Page CHAPTER VIII. DESCRIPTIONS OF THE SPECIES (continued}. Subfamily Cryptoschismid.se 279 Definition of genus Cryptoschisma 280 Cryptoschisma Schulzi, d'Archiac and de Verneuil, sp. . 281 Definition of genus Orophocrinus 283 General characters 284 Orophocrinus stelliformis, Owen and Shumard, sp. . . . 287 var. campanulatus, Hambach, var. . . 289 verus, Cumberland, sp 290 pentangularis, Miller, sp 292 Order Irregulares 294 Family Astrocrinidse 297 Definition of genus Astrocrinus 297 General characters 298 Astrocrinus tetragonus, T. & T. Austin 300 Benniei, Etheridge, jun 301 BIBLIOGRAPHY 303 ADDENDA ET CORRIGENDA. P. 1, bottom line. For Encrinus Godoni read Encrina Godoni. P. 14, Explanation of Fig. II. For ventral read radial. P. 43, line 26. For Pentremites robustus read Pentremites hemisphericus . P. 48, lines 13, 18. For P. Godoni read P. Burlingtonensis . P. 94, line 21. For P. Godoni read P. Burlingtonensis. P. 123, line 3 from the bottom. For G. McCyi read G. McCoyi. P. 126, line 12. For Metablastus Meekianus read Triccelocrinus Meekianus. P. 138, line 17. The reference figure 3 after Elcsacrinus Canadensis should be deleted. P. 140. In the list of Blastoids occurring in the Calcaire de Ferrones add Pentremitidea Lusitanica to the Pentremitidce, and Phcenoschisma Archiaci and P. Verneuili to the Codasteridse. P. 147, line 6 from bottom. For 1842 read 1843. P. 169, line 5. For Pentremitidea read Pentremitidaea. P. 170, line 16. For Orophocrinus inflatus read Orophocrinus verus. P. 171. To the list of species of Pentremitidea, add Pentremites Pailleti, de Vern. Lower Devonian; Leon and Asturias, Spain. P. 174, line 14. For PENTREMITES EIFELENSIS read PENTREMITIDEA EIFELENSIS. P. 181, line 20. For Pentremites gracilis read Pentatrematites gracilis. P. 188, line 11. For M. oblongm read M. elongatus. P. 238, line 19. For D. D. Owen read Owen & Shumard. P. 264, line 3 from the bottom. For C. gracile read C. gracilis. CATALOGUE OP THE BLASTOIDEA. CHAPTER I. THE ZOOLOGICAL HISTORY OF THE BLASTOIDEA. THE name " Blastoidea " was proposed by Thomas Say 1 in the year 1825 for a group of Echinoderms which was clearly recognized by him as distinct from the family "Crinoidea" established by Miller four years previously 2 . The zoological families of that date correspond in many cases to the classes of more modern systems, just as many of the so-called genera established by Miller are now the types of large families of Crinoids, the latter group itself being almost universally recognized as a class of the subkingdom Echinodermata. But its limits have been extended by many authors so as to include forms to which Miller's original definition is by no means applicable. According to this definition, the cup-like body containing the viscera of a Crinoid bears on its upper rim " five articulated arms, dividing into tentaculated fingers, more or less numerous." Although, from his knowledge of Parkinson's ' Organic Remains of a Former "World,' Miller must have been aware of the existence of the " Asterial Fossil " 3 (the Encrinus Godoni of De France 4 , or Pentremites of Say and later writers), 1 " On two new Genera and several Species of Crinoidea." Journ. Acad. Nat. Sci. Philad. 1825, vol. iv. pt. 2, p. 293. 2 A Natural History of the Crinoidea (Bristol, 1821), p. 7. 3 Organic Remains of a Former World (London, 1808), vol. ii. p. 235, pi. xiii. figs. 36, 37. * Dictionnaire des Sciences Naturelles (Paris, 1819), vol. xiv. p, 467. 8 2 CATALOGUE OF THE BLASTOIDEA. he never included it in his family Crinoidea, to which it has been so often referred by his successors. It has a jointed column which supports a cup-like body containing the viscera, just as in Platycnnus ; but this cup bears no arms, and it is clear that their absence was regarded by Miller as a sufficient reason for not including the Pentremite type among the Crinoidea. Say 1 remarked in like manner: "By its columnar support it is related to the family Crinoidea, but the total absence of arms and hands excludes it from that very natural group ; " and he therefore described the Blastoids as a new family of Echino- derms occupying an intermediate position between the Crinoidea and the Echinoidea, with which last group he imagined Pentremites to have some affinities. This was perhaps due to his thinking it highly probable that "the branchial apparatus com- municated with the surrounding fluid through the pores of the ambulacrse by means of filamentous processes " 2 . Later researches have shown, however, that Say and many subsequent writers were almost certainly wrong in this supposition. But while the imaginary affinity of the Blastoids with Echini has thus received a certain amount of support, their funda- mental difference from the Crinoid type has been in no way lessened ; and the results of recent investigations into the structure of both groups fully bears out Say's remarks upon the subject. His description of the " Kentucky Asterial Fossil," under the generic name Pentre- mite 3 , led to the establishment of several new species during the next twenty-five years by Sowerby, Phillips, and M'Coy in this country ; by Bronn, Goldfuss, De Koninck, Minister, and De Verneuil in continental Europe ; and by Troost, Yandell, and Owen and Shurnard in America. A new generic type was recognized by Troost and by Conrad in America (Olivanites, Troost, MS., = Nucleocrinus, Conrad, =Elceacrinus, Roemer 4 ) ; and another, which was recognized by Conrad and described by himself and by Hall 5 under the name of Stephanocrinus, was placed by Ferdinand Roemer 6 among the Cystidea, a proposal in which we cannot agree. In this country, too, Astrocrinites and Codaster were described by the Messrs. Austin 7 , and M'Coy 8 1 Loc. cit. p. 292. 2 Ibid. p. 296. 3 " Observations on some Species of Zoophytes, Shells, &c., principally fossil." American Journ. Sci. 1820, vol. ii. p. 36. 4 " Monographic der fossilen Crinoidenfamilie der Blastoideen, und der Gattung Pentatrematites im Besoudern." Archiv f. Naturgesch., 1851, Jahrg. xvii. Bd. i. p. 375. 5 Palaeontology of New York, vol. ii. (Albany, 1851), p. 212. 6 " Ueber Stephanocrinus, eine fossile Crinoiden-Gattung aus der Familie der Cystideen." Archiv f. Naturgesch. 1850, Jahrg. xvi. Bd. i. pp. 365-375, Taf. v. 7 " Proposed Arrangement of the Echinodermata, particularly as regards the Crinoidea, and a subdivision of the Class Adelostella (Echinid)." Ann. & Mag. Nat. Hist. 1842, vol. x. p. 112. 8 " On some new Palaeozoic Echinodermata." Ibid. 1849, vol. iii. p. 250. ZOOLOGICAL HISTORY OF THE BLASTOIDEA. 3 respectively. These are all well-defined generic types, and have been since recognized as valid. But in 1849 D'Orbigny 1 established the genus Pentremitidea for two Spanish Blastoids in which he supposed deltoid pieces to be absent. Roemer 2 showed, however, that D'Orbigny was here in error ; and the genus consequently fell into disuse till it was revived by ourselves in 1882 with a more precise definition 3 . During the first half of the present century the morphology of the Blastoids seems to have attracted but little attention. Roemer 4 discovered the so-called pinnules of Pentremites in 1848; and two years later Owen and Shumard 5 announced the dis- covery of Pentremites with the summit-opening closed by plates. Except in these points, however, hardly anything was added to our knowledge of the morphology of the Blastoidea, Goldfuss (the chief German palaeontologist) being led astray by their supposed resemblance to the Echinoidea ; while the descriptions of new genera were of the most superficial nature, with scarcely any foundation of anatomical facts. In the year 1852, however, all this was changed by the publication of Roemer's classical monograph 6 of the Blastoidea, and of the Pentremites in particular. Several new species of this genus were described and the existing ones re-defined ; while it was divided into four sections, each with its typical species. The careful discrimination exercised by Roemer in this classification is strikingly manifested by the fact that each of the specific types employed by him in this way is now regarded as representing a distinct genus ; while three other genera have been established for the reception of species such as Pentremites caryophyllatus, De Koninck, P. obliquatus, Roemer, sp., and P. pentangular? s, Miller, sp., which were respectively placed by Roemer in the first three sections of the genus, but with a " query" attached in each case. Roemer further gave an elaborate diagnosis of a very remarkable type, Elceacrinus, which had been distinguished by both Conrad and Troost as generically distinct from Pentremites, though neither author had ever given a proper description of it. Important, however, as was Roemer's contribution to the systematic arrangement of the Blastoidea, it was altogether eclipsed by his great additions to our knowledge of their morphology. He gave a careful analysis of the three groups of plates forming the calyx of a Blastoid, and was the first who clearly showed the relation 1 Cours elementaire de Palcontologie et de Geologic stratigraphique. 1852, vol. ii. p. 139. 2 Archiv f. Naturgesch. 1851, Jahrg. xvii. J3d. i. p. 369. 3 " On certain Points in the Morphology of the Blastoidea, with Descriptions of some new Genera and Species." Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 220. 4 " Ueber gegliederte, aus Kalkstiickchen zusammengesetzte Tentakeln oder Pinnule auf den sogenannten Ambulacral-Feldern der Pentremiten." Neues Jahrb. f. Mineral. 1848, pp. 292-296. 5 " Descriptions of Fifteen new Species of Crinoidea from the Sub-Carboniferous Limestone of Iowa, collected during the U.S. Geological Survey of Iowa, Wisconsin, and Minnesota in the years 1848-49." Journ. Acad. Nat. Sci. Phil ad. 1850, vol. ii. part 1, p. 65. 6 Archiv f. Naturgesch. 1851, Jahrg. xvii. Bd. i. pp. 323-397, Taf. i.-v. B2 4 CATALOGUE OF THE BLASTOIDEA. of the so-called deltoid plates to the summit-openings ; while he laid the foundation of a scientific study of the various ambulacral structures, and discovered the remark- able complex organs which lie beneath them, now generally known as the hydrospires. There can be little doubt, too, that he was correct in assigning a generative function to this apparatus and to the summit-openings, though it is probable that they had other functions as well. Roemer concluded with a reference to the systematic position of the Blastoidea. Although he placed them in the order Crinoidea, he recognized, as Say l had pre- viously done, that they agree with the Cystids and differ from the true Crinoids in the absence of arms. Unaware of the excellent name " Pelmatozoa " proposed by Leuckart 2 four years previously for the three groups of stalked Echinoderms, lloemer, like many other naturalists, extended the name Crinoidea to include the armless forms ; and, regarding it as of ordinal value, he considered the Blastoids, Cystids, and Brachiate Crinoids as equivalent families or sections of the order. The prin- ciples of Roemer's classification have been very generally adopted both in this country and abroad ; but, owing to the elevation of the Echinoderms to the rank of a subkingdom, the groups which he considered as families are now regarded as classes or orders. There is some doubt, however, as to whether the Blastoids and Cystids are in reality sufficiently distinct to rank as separate classes, for a large number of apparently intermediate forms have been discovered during the thirty years since Roemer wrote. The fundamental differences between Pentremites and Echinosphcerites stand out even more clearly now than they did in 1850 ; but, on the other hand, it is difficult to assign a definite position to Hybocystites and to some other types of which Roemer knew nothing. A short time before the appearance of Roemer's Monograph, Owen and Shumard 3 published descriptions of four new species of Pentremites from the Carboniferous Limestone of Iowa, U.S. One of these was founded upon an internal cast, as to the generic position of which there must naturally be a good deal of doubt, but the other three are now recognized as representing different genera, viz. Granatocrinus, Cryptoblastus, and Orophocrinus. In the year 1854 was published the classical memoir of De Koninck and Le Hon 4 upon the Carboniferous Crinoids of Belgium, among which they included five so-called Pentremites. Three of these are now ranked with Orophocrinus and another with Journ. Acad. Nat. Sci. Philad. 1825, vol. iv. pt. 2, p. 292. 2 Ueber die Morphologie und die Verwandtschafts-Verhaltnisse der wirbellosen Thiero. Braunschweig, 1848, p. 42. 3 Journ. Acad. Nat. Sci. Philad. 1850, vol. ii. pt. 1, p. 64. Reproduced, with additions, as " Descriptions of one new Genus and twenty-two new Species of Crinoidea from the Subcarboniferous Limestone of Iowa," Report Gcol. Survey Wisconsin, Iowa, and Minnesota, 1852, pp. 587-598. 4 " Recherches sur les Crinoi'des du Terrain Carbonifere de la Belgique." Mem. Acad. Roy. Bclgique, 1854, Mem. 3, pp. 189-204. ZOOLOGICAL HISTOEY OF THE BLASTOIDEA. 5 Phasnoschisma, while the last, Pentremites crenulatus, Roemer, is the type of Mesoblastus, one of our latest genera. Four more species were described in 1855 by Shumard J , who was the first American author to use Roemer's nomenclature ; while at the same time he brought forward some important new evidence respecting the closure of the summit-openings by additional plates, and three years later he published some further observations upon the same subject 2 . The year 1856 witnessed the establishment by Shumard and Yandell 3 of another new genus, Eleutherocrinus, for a very remarkable asymmetrical Blastoid from Kentucky; and during the next few years a great number of new species of Pentremites were described by Hall, Lyon, Shumard, Meek and Worthen, and others. Some important descriptions of Elceacrinus and Eleutherocrinus were published in 1862 by Prof. J. Hall 4 , who also proposed to use Troost's MS. name Granatocrinus for species of the type of Pentremites Norwood^ Owen and Shumard. During the next year some valuable observations on the closure of the summit and ambulacra were published by Dr. C. A. White 5 , who also revived Say's theory respecting the presence of tentacles on the ambulacra, although Roemer had pointed out the difficulties involved in this view. The year 1864 witnessed Von Seebach's proposal to make Pentremites stelliformis, Owen and Shumard, the type of a new genus, Orophocrinus 6 ; and in the following year were published the most important observations of Rofe 7 on the structure of the hydrospires or subambulacral lamellar tubes in the British species of Granato- crinus and Cadaster, with his suggestion that they probably served a respiratory function. About this time also Shumard 8 proposed to separate Pentremites Rein- wardti and its allies under the generic name Troostocrinus. 1 " Palaeontology " in Swallow's First and Second Annual Eeport, Geol. Survey Missouri, 1855, pp. 185- 187. 2 " Descriptions of new Species of Blastoidea from the Palaeozoic Rocks of the Western States, with some Observations on the Structure of the Summit of the genus Pentremites." Trans. St. Louis Acad. Sci. 1858, vol. i. pt. 2, pp. 238-248, pi. 9. 3 " Notice of a new Fossil Genus belonging to the Family Blastoidea, from the Devonian Strata near Louisville, Kentucky." Proc. Acad. Nat. Sci. Philad. 1856, pp. 73-75, pi. ii. 4 Fifteenth Annual Eeport, New York State Cabinet of Natural History (Albany, 1862), pp. 144-153. 5 " Observations on the Summit-Structure of Pentremites, the Structure and Arrangement of certain parts of Crinoids, and Descriptions of New Species from the Carboniferous Eocks at Burlington, Iowa." Boston Journ. Nat. Hist. 1863, vol. vii. no. 4, pp. 481-489. 6 " Uebcr Orophocrinus, ein neues Crinoideengeschlecht aus der Abtheilung der Blastoideen." Nachr. kgl. Gesellsch. Wissensch. zu Gottingen, 1864, pp. 110, 111. 7 " Notes on some Echinodcrmata from the Mountain Limestone," &c. Geol. Mag. 1865, vol. ii. pp. 248- 251, pi. viii. 8 " A Catalogue of the Palaeozoic Fossils of North America. Part I. Palaeozoic Echinodermata." Trans. St. Louis Acad. Sci. 1865, vol. ii. no. 2, p. 384, note. 6 CATALOGUE OF THE BLASTOIDEA. Several species of Pentremites (or rather Pentremitidea] from the Eifel were described by Schultze l in 1866 ; and Granatocrinus was formally adopted by Meek and Worthen 2 in the same year. Two years later they suggested the name Tricce- locrinus for a remarkable type allied to Troostocrinus 3 ; and in 1869 they proposed to establish a new genus, Codonites 4 , for the Pentremites stelliformis, Ow. & Shum., which (though unknown to them) had already been taken by Von Seebach as the type of Orophocrinus. They also confirmed White's observations respecting the closure of the summit-openings by additional plates, which likewise extend down the ambulacra so as to cover them in and convert them into tunnels. In this year, too, Billings 5 began the publication of a very striking series of papers on the structure of Crinoids, Cystids, and Blastoids, in which he devoted a good deal of attention to the morphology of Pentremites, Codaster, and Elceacrinus. The remark- able lamellar tubes beneath and between the ambulacra, which appear to have served the function of respiration, were designated by him as " hydrospires," and the summit-openings in connection with them were called " spiracles," names which have since been generally adopted. In 1873 several excellent figures of Blastoids were published by Meek and Worthen 6 ; but they were unfortunately not accompanied by any connected description of the morphological details which they illustrated so well. Three years later an attempt was made by Mr. R. Etheridge, Jun., 7 to elucidate the structure of Austin's little-known genus Astrocrinites on the basis of a new species discovered in the Scotch Carboniferous shales; and he subsequently described, under the general name Pentremites 8 ., an imperfectly-preserved fossil from the same horizon, which has since proved to belong to PhcenoscMsma. Many important observations on Blastoid morphology were published incidentally by Wachsmuth in his " Notes on 1 " Monographic der Echinodermen des Eiflerkalkes." Denkschr. k. Akad. Wiss. "Wien, Bd. xxvi. 1866, pp. 111-1J4. - k - Contributions to the Palaeontology of Illinois and other Western States." Proc. Acad. Nat. Sci. Philad. 1866, p. 257. :! " Remarks on some types of Carboniferous Crinoidea, with Descriptions of new Genera and Species of the same and of one Echinoid." Ibid. 1868, p. 356. 4 " Remarks on the Blastoidea, with Descriptions of New Species." Ibid. 1869, pp. 83-91. 5 " Notes on the Structure of the Crinoidea, Cystidea, and Blastoidea." American Journ. Sci. vol. xlviii. 1869, pp. 69-83 ; vol. xlix. 1870, pp. 51-58 ; vol. 1. 1870, pp. 225-240 ; Ann. & Mag. Nat. Hist. 1870, vol. v. pp. 251-266 and 409-416; vol. vii. 1871, pp. 142-158. * ; Report, Geological Survey of Illinois, 1873, vol. v. pis. viii., ix. 7 which we only know from the figures of Billings and Schmidt. But we imagine the suture referred to by Wachsmuth and Springer to be that between the radials and deltoids, just as is shown in the hypothetical figure given by Billings 2 , in whose interpretation of the calyx we entirely concur; and we have reason to believe that in this respect the American palaeontologists are now in complete accordance with us. E. THE DELTOID PLATES OR INTERKADIALS. Interscapular plates, Say. Second series of suprabasals, M'Coy. Superior plates, Owen Sf Shumard. Deltoidstiicke, Roemer. Interradials, De Koninck. Interradials, Shumard 6f Yandell, Second radials, Lyon. Deltoids, Sliumard. Interradials, Hall. Interradials, Meek <$f Worthen. Deltoids, Billings. Deltoid pieces, Jfambach. Oral plates, Etheridye, jun., <$ Carpenter. Oral plates, Wadismuih