H =00 ■o ■co CO CL~D (geological j$urUni of tlic Statt of |leto gorlt. PALEONTOLOGY Vol. VII. TEXT -A. 3ST 13 FLUTES- ( OXTAINIXG DESCRIPTIONS OK THE TRIL0B1TES AND OTHER CRUSTACEA ORISKANY, UPPER HELDERBERG, HAMILTON, PORTAGE, CHEMUNG AND CATSKILL GROUPS. JAMES HALL, STATE GEOLOGIST AND PALEONTOLOGIST, ASSISTED BY JOHN M. CLARKE. n*1 1° & ALBANY, N. Y.: CHARLES VAN BENTHUYSEN & SONS. 1888. State of New York, Albany, March, 1888. } Published under the supervision of the Trustees of the Stat.' Museum of Natural History, pursuant to chapter 355 of the Laws of l^s:;. DEDICATION. To His Excellency DAVID B. HILL, Governor of the State of New York . Sir: I have the honor to present to your Excellency a new volume of the Natural History of the State, being a continuation of the work on the Palaeontology of the State of New York. This volume is chiefly devoted to the description and illustration of the Trilobites and other fossil Crustacea of the Oriskany, Upper Helder- berg, Hamilton, Portage, Chemung and Catskill groups of the New York Geological Series, and comprises about three hundred pages of text and forty- nine quarto plates of illustration with explanatory text. Besides the principal subject of the volume there is included some matter supplementary to Volume V, part ii, embracing forty pages of descriptive text, with eighteen plates and explanations. These subjects together comprise the full amount of text and of plates which could be devoted to this volume under the law of 1883, while making a proportionate allowance for the Volume V, part ii, Lamellibranchiata, in two volumes, and Volume VI, already published, and for Volume VIII, upon the Brachiopoda, which is yet to be published. The present volume is the seventh of the entire series, and the fourth in order which has been published under the provisions of Chapter 355 of the Laws of 1883, by which it was directed "that the entire work should not extend beyond five bound volumes in addition to those already issued." The entire number of species of Crustacea described and illustrated in this volume is one hundred and forty-four, which are included under twenty-eight iv DEDICATION. Genera. Of this number ninety-seven are Trilobites, which have perhaps a greater general interesl than any other class of fossils. I he material furnishing these descriptions and illustrations is chiefly the result of field collections made within the State of New York; some of the specimens dating hack as far as the year 1832; including also specimens from the collections of private individuals, and from the cabinets of institutions of learning, which have been placed at the disposal of the author for the purpose of enriching this volume. While the work is far from reaching that degree of completeness which the author could desire, it must be regarded as the best which could be accom- plished under existing circumstances; presenting, as it does, a systematic arrangemenl of the material at our disposal, it will furnish to students and teachers the means of study, and classification of their own collections, and in this view the author will hope that it may not prove unworthy of a place among the series of volumes intended to illustrate the Natural History of the Statk of New York. I have the honor to be, With great respect, Your obedient Servant, JAMES HALL, Albany, March, 1888. State Geologist and Paleontologist. TABLE OF CONTENTS. Page. DEDICATION iii, iv TABLE OF CONTENTS . v Errata ............... vi I REFACE ............... vii— x INTRODUCTION xi-xx SYNOPSIS OF THE GENERA xxi DESCRIPTIONS OF SPECIES 1-220 Caltmene 1-4 homalonotus 4-11 Bronteus . . . . . . . . . . . . . . 12, 13 Phacops 14-27 Dalmauites 28-68 Acidaspis .............. 69-72 Lichas 74-88 Proetds 89-134 Phaethoxuies 134-140 Cyphaspis . . 140-152 Protolimuixs 153-155 Eerypterls 156-158 Stylos i -res 158-162 Ceratiocaris ............. 163-165 Echinocaris 166-181 Eltmocams 181-183 Tropidocaris 184-186 Mesothyra 187-194 Dithyrocaris . 194 Rhihocaris. . . 195-198 Spathiocaris, 199, 200 Dipterocaris 200-202 Paljeopal.emos ............ 203-205 Estheria 206,207 Schizodisces 207, 208 vi TABLE OF CONTENTS. DESi RIPTIONS OF SPECIES (Continued): PAGE. Pi;. , rua 209, 210 l'\: 3IA 210,211 Strobilepis ........... 212-215 Ti rrilbpas 215-220 SUPPLEMENTARY 221,222 rABULAR ARRANGEMENT OF GENERA AND SPECIES . . . . 223-230 INDEX 231-236 PLATES \NI> EXPLANATIONS i-xxxvi ERR A.T^l. Page L, lim 9, read Pj we XXV, figs. 1. 2. 7, lim 6, read Plate II, figs. 1-12; Plate IV, figs. 1-7; Plate V, figs. 1-14. Page 19, line 15, for 55, read 6a. Page 25, line -'. for oceitanus, read occitanh 31, line 9, for 26, read 29. P:il"- 32, line l. for pi lifera, read spiniferus. Page 32, line 18, for Conrad, read Green. ne 10, for XII, read XIII. Page 45, lines :!1 and :vi, for species, read variety. Page 49, line 5, for 1832, read 1S35. > t 9 between 3-6 and 10. Page 62. line 2, add Plate X, fig. 14. 62, line 21, read Dalmanites (Chasmofs) ujchiops, var. sobrinus, n. var. 63, line 5, for Asaphus laticostatus, read Calymene anehiops. 68, line J, I'm- XI b, read XI a. 75, line 22, I'm- there, read /;«/-e. Pagi 158, line l':!. for Claypoll, read Claypole. oe I''., ('"]■ II vi i . read Wright. Page 223, line I'.', for Phai opidi e, read Phacopidjk. E3tP] Plate xxxv, Sg. 22, I'm- Goniatites sinuosus, read Gmiatites complanatus. PREFACE. This volume contains the descriptions and illustrations of the Trilobites and other Crustacea of the Oriskany, Upper Helderberg, Hamilton, Port- age, Chemung and Catskill groups of the New York Geological Series, which essentially constitute the equivalent of the Devonian System of Europe. Some descriptive matter and illustrations, supplementary to Volume V, part ii, are also included. The volume, as it will now go to the public, is very different in its scope and character from the original conception and plan of the author. While still free to devise a scheme for the completion of the Palaeontology of New York, in what appeared to him the most satisfactory manner, he had contemplated a review and revision of all his previous work upon the Pal.eozoic Crustacea, the early part of which had been done with very incomplete and often unsatisfactory material and equally imperfect knowledge of the subject. With this end in view, an effort was made, in 1873, through private subscription of the citizens of Albany, to purchase from Mr. C. D. Walcott a collection of Tren- ton limestone fossils, mainly for the sake of the Trilobites which it contained. This plan failing, the collection went to the Museum of Comparative Zoology, in Cambridge. At a later period, a second similar collection was offered to the State Museum by Mr. Walcott, but its purchase was not effected. This collec- tion like the preceding one was purchased by the Museum in Cambridge, which now possesses a series of New York Trenton limestone fossils far superior to any other in the country. In the meantime the author had, at his own personal expense, sent an assist- ant into the field to make collections, especially of Trilobites, from the rocks Vlll PREFACE. below the Trenton limestone, intending to extend the work of collecting to all the know n localities of primordial fossils within, and adjacent to the State. The lit of the first season's work proved so unsatisfactory and disappointing that this plan was abandoned with regret, and nothing farther was attempted in that direction. From the tune of the completion of Volume V, part ii, at the close of 1879, the failure to make appropriations for the publication of this work, left in the hands of the State Geologist a large amount of matter prepared, or partially ready for publication. Of this material were eighty plates of Lamellibranchiata, which, with twelve additional plates, now constitute the illustrations of Volume V, part i. published in two volumes. A considerable number of the plates pub- lished in Volume VI had, at that time, already been lithographed ; besides eight plates of Crustacea for Volume VII. Of the Brachiopoda, which in the present arrangement are to constitute Volume VIII, twenty-seven plates had been lithographed when, in 1881, all progress in the Pal.eontology of New York was suspended. rpon resuming the work, under the limitations of the law of 1883, it came necessary for the author to content himself with a volume restricted to thr description and illustration of the Devonian Crustacea, and in order to make this one of a size approximating the other volumes, it became necessary to include the supplementary material of Volume V, part ii, originally intended for a separate publication, and which here follows the principal matter giving title to the volume. Under existing circumstances, it is not at all probable that the author will ever have the opportunity of reviewing and revising his earlier work upon the Trilobitic faunas of the older rocks, but he may hope that in the near future the scientific institutions of New York may feel it incumbent upon them to present to the public a work upon these fossils worthy of the subject and of the State whose position is so well established as the pioneer and munificent patron in the science of Paleontology. There is no longer any difficulty in finding willing and able hands to perform such a work, and the material, though scattered in the collections of different institutions, could readily be brought PREFACE. ix together for such an Important purpose as a monograph of the Paleozoic Crustacea. In taking leave of a work which has in the past occupied his mind and prompted his earnest endeavors, he can only regret that the circumstances attending its final production have been less felicitous than he could have wished. In the preparation of the matter for the press, and in the critical study of the material, the author acknowledges with great satisfaction the able and untiring efforts of his assistant. Mr. John M. Clarke. The author acknowledges the liberality with which specimens have been placed at his disposal for study and comparison, and begs leave to express his obligations to the following-named gentlemen and institutions: o^ Dr. J. S. Newberry, .. ._ .. New York, N. Y. Mr. Louis Bevier, . _ __ __ Marbletown, N. Y. Mr. Cornelius Van Gaasbeck,.. __ Kingston, N. Y. Prof. S. G. Williams, __ Ithaca, N. Y. Prof. H. S. Williams, _ . . . _ . Ithaca, N. Y. Prof. J. F. Whiteaves, Geological Survey of Canada, Ottawa, Canada. Mr. R. D. Lacoe, __ -_ -- -- Pittston, Penna. Prof. W. H. Barris, __ _. Davenport, Iowa. Mr. D. S. Chatfield, .. .... Syracuse, N. Y. Mr. A. 0. Osborne, .. _. Waterville, N. Y. Mr. D. D. Luther, .. __ Naples, N. Y. Dr. C. Rominger,.. __ __ __ ._ Ann Arbor, Mich. Sir William Dawson, _ _ ._ -. __ -- Montreal, Canada. Prof. B. K Emerson, .. - - - Amherst, Mass. Mr. Charles E. Beecher, .. .. ._ New Haven, Conn. National Museum,.. .. .- -_ -- Washington, D. C. American Museum of Natural History, New York, N. Y. Prof. J. P. Lesley, _ - - - - Philadelphia, Penna. Prof. R. P. Whitfield, . _ .. New York, N. Y. Dr. J. Pohlman, __ __ Buffalo, N. Y. Prof. George H. Cook, - . . ._ . - - - New Brunswick, N. J. Prof. S. Calvin, .. .. __ _. _- Iowa City, Iowa. x PREFACE. All the later drawings have been made by Mr. E. Emmons. Many of the plates which hear the name of Mr. George B. Simpson, were drawn between 1^70 and L881, and have remained in the hands of the author awaiting publication. The accuracy and completeness of the original drawings will be acknowledged both by the author and by the student in this department of Palaeontology. Much the larger proportion of the lithography has been done by Mr. Philip Ast. the completion of some of the plates bearing his name dating back to 1872. In the continuation of the work, since 1886, Mr. Paul Riemann has done a smaller number of the plates. In consequence of the pressure for the comple- tion of the work within a specified time, the standard of quality originally established has not been maintained in this and the preceding volume, but the deterioration has principally come through the printing of the plates. The typographical and mechanical execution of the work speaks for itself. THE AUTHOR. March, 1888. INTRODUCTION. The Crustacea discussed in this volume are, primarily, the species from the Devonian formations of the State of New York, and, incidentally, such species from other horizons as it has seemed important to introduce into the work either for purposes of comparison or for the furtherance of our knowledge in other respects. Since comparatively few species of the North American Devonian Crustacea have been found to occur exclusively outside the limits of the State of New York, these extra-limital species, for the sake of completeness, have been brought within the scope of the work. The volume may, therefore, for the present be regarded as a monograph of these Devonian Crustacea (not including the Ostracoda). In the ensuing discussions of the species the order followed is taxonomic, although no single system of classification has been rigidly adhered to. The chronological arrangement of the species is therefore subordinated to the zoological order of the genera and families. I. Historical. The first published notice of the North American Devonian Trilobites was given b}' Alexandre Brongniart ("Crustaces Fossiles," 1822), who referred to his species Calymene macrophtalma, two American specimens, one of which is probably referable to the species Phacops bufo or P. rana, Green, and the other, a plaster cast of a specimen which subsecpiently served as the type of Calymene [Dalmanites] anchiops, Green. In 1824, Dr. James E. Dekay (Annals of the Lyceum of Natural History, New York), recognized the Calymene macrophlhalma (= Phacops rana), " on the Helderberg Mountain near Albany, and at Coshung Creek, near the Seneca Lake.'' In 1832, Professor Amos Eaton (Geological Text-book), described the species Nuttainia sparsa (= Homalonotus Dekayi, Green), and Asaphus {= Dalmanites) selenurus. This work was followed, in the same year, by "A Monograph of the Trilobites of North America, with Colored Xll ].X 'PRODUCTION. Models of the Species." by Jacob Green, M. D., accompanied by a Supplement in L835. This Monograph included several of the best known and most char- ristic of the Devonian species, namely: Asaphus 1= Dalmanites) pleuroptyx. A. (= D.) mynnecophorus. . =Phaco} Calymene (= D.) anehiops. i .. . /• ... op rana. Calymene* Odontocfphala = D. selenums. In the Annual Reports of the Palaeontological Department of the New York Stale Geological Survey, for 1839, 1S40 and 1841, Mr. T. A. Conrad described the species Odontocephalus selenurus (Eaton), Asaphus (—Dalmanites) aspectans, Calymene marginalis (== Proetus Rowi, Green, 1838), Asaphus? denticulatus (= Dal- manites aspectans), and Asaphus? acantholeurus (= Dalmanites myrmecophorus, Green). From this date onward to the year 1861, brief notices of American Devonian Trilobites were published by various writers, viz.: Burmeister, Emmons, Owen, Vanuxem. Castelnau, Hall, Shumard, I n 1 86 1 , Professor James Hall published (Descriptions of New Species of Fossils from the Upper Helderberg, Hamilton and Chemung groups; in advance sheets of the Fifteenth Annual Report of the New York State Cabinet of Natural History) a brief revision of the previously described Devonian Trilobites from the State of New York, with the addition of several new species. The follow- ing species were discussed : platyS, I rREEN. // nalonotus Dekayi, Green. /'/m, opt ■ • it tata, If all. Phacops bombifrons, Hall( = Ph. cristata, partim). Phacops rana, Green. Phacops bufo, Green. a, Hall. Phacops nupi ra, Hall i 1843). Dahiu , Hall | Dalmanites) aspectans, l ■ iNBAD. Dalmania (= Dalmanites) mynnecophorus, Green. Da ma ;" Dalmanites) emarginata. Hall. Pit tome, Hall. ■ iisi liuiii/iii. Green. Dalmania (= D . Eaton. i lites) bifida, Hall. Da i i 1 1 1 /■■> Ha, Hall. : Dalmanites) coronata, Hall. I- Dalmanites) anehiops, Green. Dalmania(=Dalinanites)anchiops,w.armata,HA.hL Dalmania (== Dalmanites) Calypso, Hall. Dalmania (= Dalmanites) Erina, Hall. Dalmania {= Dalmanites) nun-nips, Hall. Lichas grandis, Hall. Liehas armatus, Hall (= L. Briopis, Hall). Pnn Ins < 'onradi, Hall. Proetus a iiijnslifriiiis. Hall. Proi Ins tJesione, Hall. Proetus crassimarginatus, Hall. Proi I us i turns. Hall. P Hits canaliculatus, Hall. I'm, I ns Y, rm aili, Hall. Proitus Huhli iniiiii. Hall. Proetus null run ji/nil us. Hall. Proetus marginalis, Conrad. Proetus Rowii, Green. Proetus longicaudus, Hall. Proetus occidt as, Hall. INTRODUCTION. xiii These species were, at this date, mostly published without illustration, but figures of these and a few additional Devonian species were given in the Illustrations of Devonian Fossils, in L876. The following authors have published descriptions or notices of the American Devonian Trilobites, and full reference to their works will be found under the generic and specific synonymies : Barris, Conrad, Meek, Walcott, Billings, Eaton, Nicholson, Whitfield, Brongniart, Emmons, Owen, Williams, H. S., Burmeister, < Ireen, Shumard, Williams, S. ( '<., Castelnau. Hall, Yanuxem, Worthen. Clarke, Kayser, "Wogdes, The other orders of the Crustacea have only more recently attracted the attention of American writers. The Xiphosura have been discussed by Wil- liams and Packard; the Eurypterida, by Hall and Claypole; the Phtllocarida, by Hall, Whitfield, Clarke, Packard, Beecher, Woodward and Jones; the Decapoda, by Whitfield; the Phvllopoda, by Clarke, Packard and Jones; and the Cirripedia, by Whitfield and Clarke. II. Classification. In the discussions of the species, it has not seemed advisable to accord a strict adherence to any given system of classification The Trilobites, which include the larger and, for the geological student, the most important part of the work, stand first in order of treatment ; the other orders of the sub-class to which they belong, being considered in the latter portion of the work. In the introductory discussion of the genera the same order is followed. The classification which has been adopted, with modifications, for the purpose of the work, is the following: *It is understand that a "Bibliography of the Palaeozoic Crustacea." by Li.-ut. Vbgdes, is read] for press at the present writing. xiv INTRODUCTION. CLA.SS, CRUSTACEA. Sub-Class A. Entomostraca. ORDER I—CIRRIPEDIA. Family a. Lepadid^;. Genus 1. Strobilepis. 2. Turrilepas. Family b. Balanid^e. Genus 3. Protobalanus. ORDER II.—PHYLLOPODA, Family a. Limnadiad k Genus 4. Esther ia. " 5. Schizodiscus. ORDER III.—TRILOBITA. Family a. Calymenid.k. Genus 6. Catymene. " 7. Ilomalonotus. Family b. Bronteid^e. Genus 8. Bronteas. Family c. Phacopid.e. Genus 9. Phacops. " 10. Dalmanites. Sub-genus 1. Hausmannia. " 2. Coronura. 3. Cryphaus. 4. Odontocephalus. " 5. Chasmops. Family d. Acidaspid^e. ( renus 11. Acidaspis. Family e. Liciiad.e. ( icii us 12. Lichas. Sub-genus 1. Terataspis. 2. Conolichas. 3. Hoplolichas. INTRODUCTION. xv Family e. Lic-hads — Continued. Sub-genus 4. Arges. 5. Ceratolichas. 6. Dicranogmus. amily f. Proetid^e. Genus 13. Proitus. " 14. Phailhonides. " 15. Cyphaspis. Sub-Class B. Merostomata. ORDER IV.—XIPHOSURA. Family a. LimulidjE. Genus 16. Protolimulus. ORDER V—EURYPTERIDA. Family a. Eurypterii* i . Genus 17. Eurypterus. " 18. Stylonurus. Sub-Class C. Malacostraca. ORDER VI.—PHYLLOCARIDA. Family a. Ceratiocarid.e. Genus 19. Ceratiocaris. " 20. Echinocaris. " 21. Elymocaris. " 22. Tropidocaris. Family b. Pinacarid^e. Genus 23. Mesothyra. Family c. Rhinocarid^e. Genus 24. Rhinocaris. Family d. Discinocaride. Genus 25. Spathiocaris. " 26. Dipterocaris. ORDER VII.— DEC APOD A. Family a. Caridid.e. Genus 27. Palaopalamon. XVI IXTRODUCTJON. III. Chronological Distribution. Oriskany sandstone. In the eastern outcrops of this formation but a single Crustacean species is known, the gigantic Homalonotus major, from Ulster county. In the western extension of these rocks into the Province of Ontario, are the species 'Phacops cristata, Dalmanites (Ilaiismannia) pleuroptyx and Dalmanites (Chasmops) anchiops, ail of which occur in the overlying Upper Helderberg limestones, a fact which indicates the close alliance of the western Oriskany fauna to the true Devonian. Upper Helderberg group. Cauda-galli grit. No Crustacea have been found in this formation. Schoharie grit. The rich Crustacean fauna of these rocks is exclusively trilobitic, and con- Bists of eighteen species from the local development of the formation in eastern New York. These arc : Caly ■ ii platys. LicJias (Terataspis) grandis. Phacops cristata. Lichas (Conolichas) hispidus. Dalmanites (Hdusmannia) concinnus. Proetus Conradi. /i. tanites (Coronnra) emarginatus. Proetus angustifrons. Dalmanites (Corycephalus) regalis. Proetus Hesione. Dalmanites [Chasmops) anchiops. ProHus crassimarginatus. Dal tanites (Chasmops) anchiops, var. armatus. Proetus sp. DalmaniU (Chasmops) anchiops, var. sobrinus. Phaethonides arenicolus. .1. idaspis callicera. Cyphaspis minuscula. In addition to these are the species Proetus curvimarginatus and Proi'tus latimar- ginatus, from the sandstone beds at Pendleton, Indiana, which lie at the base of the Corniferous limestone, and contain a fauna closely allied to that of the Schoharie grit in the State of New York. Corniferous limestone. The greatest numerical development of the Devonian Crustacea, as a whole, is found in this extensive formation. The species are, however, mostly of Trilobites which here attain their specific and individual culmination, all other orders of Crustacea, excepting the Cirripedia being unrepresented. The INTRODUCTION. XVI 1 condition of preservation of the fossils is often unsatisfactory, the .specimens being generally in a disjointed or fragmentary condition : moreover the char- acter of the matrix is such thai it is often a matter of great difficulty to prepare the specimens in a proper manner for study. When the test of the animal has been silicified the matrix is usually in the same condition, and when preserved in the limestone, the substance of the test is usually softer and more friable than the matrix. The transported boulders of chert which are found abundantly in the drift accumulations south of the lines of outcrop of these rocks, and have become decomposed by the gradual removal of the calcic carbonate mixed with the silica, have proven a very fruitful source of instructive specimens. On account of the usually fragmentary condition of the specimens, a few of the species here described may eventually prove to be founded upon different parts of similar animals. The following fifty-two species at present constitute the Crustacean fauna of this formation : TR1LOBITA: 'i/inrne platys. Phacops cristata. Phacops cristata, var. pipa. [?] Phacops rana. Dalmaniles ill ] Dalm ■ Boullii. Dolman': rus. Dalmanites | Odontocephahis) bifidus. Dal tocephalus) jSOgeria. Dalmaii ites (Odontoet / tJtalus) con mat its. Dalmanites (Cory cepht Dalmanites (Ohasmops) anchiops. Dalmanites (Ohasmops) a par. armatus. Dalmanites (Chasmops) Calypso. Dalmanites (Chasmops?) Erina. Da macrops. Acidaspis eallicera. Acidaspis sp. LicJtas ('/■' rataspis) grandis. !,',• lias | 1 'ova "" has) ! ispidus. Lichas (Conolichas) Eriopis. T1UL0BITA : Lichas (Hbpl i a as. Lichas (Arges) eontusus. Li i ' > as) gryps. Lichas i ( Proei Proetvs follicep Pii itus clarus. Pi i US. Pn■<; I n'S Hnlli. Pro, ttis jtjumts. * Proilus Phocion. * Pro,! its Prouti. /', etus .\> vadCB. ' PrOl his nr, 'i,l, us. Proitv ■ ')l igh audits. Phaithonides gt mmceus. * Phaithonides (?) ,1, nticulatus. i "yphaspis ornata. Oyphaspis ornata, var. baeeata. i 'ypJiaspis , raspedota. Of this list those bearing a, star (*) arc from localities outside the State of New- York, which may be regarded as of the age of the Hamilton group. Of the Phyllocarida, are : EcMnocaris punctata. Elymocaris capsella. Tropidocaris Bumiltonice. MesotJiyra Neptuni. Of the Piivllopoda, the species : Estht Ha pulex. Of the Cirripedia : Strobilepis spinigera. Turrilepas I>, nmi, as. Turrilepas squama. Mesothyra spuincBa. | Bithyrocaris) Belli. Hli'iiinniris ml iimhimi. BMnocaris scaph Schizodiscus capsa. Turrilepas nitidulus. Turrilepas foliatus. Turrilepas !• «< r. Of these forty species, twenty-nine occur within the limits of this State. Tally limestone. Trilobitic remains only have been found in this formation, and these are, with one exception, the more common species of the underlying shales. Brunt, us TuU'iiis. Phacops rii mi. Dalmanites (Oryphmus) Boothi. Dalmanites (Cryphceus) Boothi, var. CaUiteles. Pro, his Rowi. ProettiS ninrruii plml ns. Genesee shales. These bituminous beds have produced but a single Crustacean, Ceratiocaris longicauda. Portage group. Under this designation, as used in this work, are included all the shales and sandstones lying between the Genesee shales below and the lowest sandstones bearing a typical Chemung fauna. These beds and their equivalents in other XX INTRODUCTION. States have produced no Trilobites, their Crustacean fossils being mostly Phyl- LOCARIDA. They arc : i 1 1 tocaris multinodosa. Mesothyra Oceani. Spathiocaris Etnerson i. DipteroearU i» nwB-Dasdali. J>ipli rocaris pes-ci rva . Palwopalwmon N< wot rryi. Chemung group. In the sandstones of this period the Trilobites are represented by two species. Phacops nupera (sec page 27) and Cyphaspis lavis ; the Xiphosura, by pecies Protolimulus Eriensis ; the Eurypterida, by Earypterus Beecheri ; the Phyllocarida, by : "j-imitn. Ti-opidocarls InU rrupta. Dipterocaris Proene, li'iph rocaris pes-cervcB. The Cirripedia are represented by Turrikpas (?) Newberry i ; making a total of eleven species. Catskill group. The sandstones of the town of Andes, Delaware county, and of Meshoppen, Wyoming county, Pennsylvania, have furnished specimens of the only known Crustacean from this formation, SI ylonur us excels/or. SYNOPSIS OF GENERA. ORDER, TRILOBITA. Family, Calymenidje. Genus C A L Y M E N E , Brongniart. 1822. 1759. Bntomolithus, Linne (partim). Act. Holm. 22. 1781. Trilobus, Brdennich. Kjoben. Selsk. Skrivt. Nye Saml. I. 1821. J: I tes, Wahlbnberg. Nov. A S Si i. Qpsal., vol. viii. Iv-'-. ■ . Brongniart. lli-t. Nat. Crust. Fossiles. 1826. , Dalman. Deber Palseaden. 1S29. Calymene, Holl. Handb. d. Petref. 1^:;.. Calymene, Green. Monog. N. Am. Trilob. 1835. Calymene, Bronn. Leth&a Gteognostica. 1S37. Calymene, Hisinger. Lethrea Suecie.a. 1837. I . Bdckland. Bridgewater Treat., vol. ii. Js37. Calymene, Qdenstedt. Wiegmann. Archiv., vol. iv. 1839. . Mi : CHISON. Silurian System. 1839. Calymene, Emmrich. De Trilobitis. 1839. I . Conrad. Second Ann. Rept. Pal. N. Y. 1540. Calij - igwick and Mdrchison. Trans. Geol. Soc. 1 S4C I i ■ . M se-Edwards. Hist. Nat. Crustaces. 1541. • e, Conrad. Fifth Ann. Rept. Pal. N. Y. 1542. Calymene, Emmons. Rept. Second Hist. N. Y. 1842. Calymene, Vandxbm. Rept. Third Dist. N. Y. ls-)3. Calymene, Goldfuss. Nenes Jahrb. fur Min., vol. v. 1843. Caly B rmeister. Organ, d. Trilobiten. Is43. Calymene, Port-lock. Geol. Rep'. Londonderry. 1543. Calymene, Hail. Rept. Fourth Dist. X Y. ls44. Caly ie, D'Archiac and De Vernedil. iElt. palaeozoisch. Geb. im Nord. von Deutschl. und Belgien. (Leonhardt). 1*4.". i \il yminr, Emmrich. Neues Jahrb. fur Min. 1846. Calymene, Geixitz. Grundr. d. Versteinerungen. 1846. Calymene, Pictet. Traits elem. d. Palebnt., vol. iv. 1546. Calymene, Barrande. Notice Prelim, and Nouv. Trilob. L846 Cah . Rouault. Bull. Soc. geol. d. France, vol. iv. 1846. Calymene, McCoy. Synop. Sil. Foss. Ireland. 1846. Calymene, Betiiioh. Untersuchungen iib. Trilob. 1547. Calymene, Corda. Prodrom Monog. bohm. Trilobiten. 1847. Calymene, Hall. Pal. N. Y"., vol. i. 1848. Calymene, Salter. Mem. Geol. Surv. United Kingdom, vol. ii. XX 11 SYNOPSIS OF GENERA. 1843 , s Mem. Geol. Surv. United Kingdom, Decade ii. . M Cot. Ami. and Mag. Nat. Hist., vol. iv. V) - p. Pal. 1 '■'■ I ivardian Mus. 1852, ••■ - Sil. d. B ifime, vol. i. 1852. ' 1. Surv. Wis., Iowa and Minn. 1S55. , Si hard. 1 :■■] >t. Geol. Surv. Missi . Emmons. Amer can I teology. 1858. 'art. Jour. Geol. Soc . Hall. Thirteenth Rept. N. V. State Cab. Nat. Hist. 1861. Call .llii. pt. Wisconsin. 1862. ■ , lIcCoi -; : Sil. Foss. [reland. 1862. Calymt w. Hall. Fifteenth Rept. X. V. State Cab. Nut. Hist. i br. Monog. Brit. Trilobites. i .Salter. Mem. j United Kingdom, is,;; Calym e, Hall. Twentieth Rept. N. Y. State Cab. Nat. Hist. Ve i. camb. och. silur. Aflag. . Haidbnhain. Zeitschr. ,1. deutsch. geol. Gesellsch. ls;j. (, , Babrande. Syst. Sil. d. Boheme, vol. i, suppl. l-~7:i. Calymene, Mbbe. Geol. Surv. Ohio, Palaeontology, vol. i. Is;;,, i a lynu te. Meek. 1. Surv. Ohio, Palaeontology, vol. ii. 1876. Calymt i£, Hall. Illustration ,t Devonian Fossils. n.r:i palseo 1878. ' , Angblin. Pal. Scandinavica, pt. i. 1879 i , Ui an h. Jour. Cin. Soc. Nat. Hist., vol. ii. [879 , Novak. Studien an Hypostomen, i. Proc. Acad. Nat. Sci. Phil. 1881. ■ Hall. Eleventh Rept. Geol. Surv. Indiana. lssi. ( ':; , Wai ott. Bull. Mus. Comp. Zoology, Harvard Coll. . Novak. Zur Kenntn. bohmisch. Trilob. 1SS4. ' '. vak. Studien an Hypostomen, ii. L885. Calymene, Zittel. Handb. d. Palaeontologie. 1885, Calymene, QShlert. Bull, de la Soc. d'Etudes scientif. d'Angers. 1887. ■ Foerste. Bulletin, Denison University. Diagnosis. Body oval. Cephalon semicircular, nearly three times as wide as long; rounded in front, genal angles blunt, rarely produced into spines. Anterior margin somewhat elevated ; gla- bella strongly arched, sharply limited by deep dor- . and divided into three pairs of sub-spherical lobes, by the unequal, short lateral furrows, the posterior pair of which bifurcate near their proximal extremities. Cheeks convex, and with a distinct marginal border. Eyes situated somewhat anteriorly ; visual surface small, homocorneal. The facial sutures begin at the genal angles, and pass in a sigmoid curve to the eyes, thence, parallel to the axis, to the anterior margin, where they are united by the SYNOPSIS OF GENERA. xxiii transverse frontal suture. Hypostoma small, elongate-sub-quadrate; sides gently concave; posterior edge emarginate. Thorax composed of thirteen broad segments; axis tapering backward. Pygidium bearing six to eleven distinct annulations; axis regularly tapering from the thorax. Genus HOMALONOTUS. K(enig. 1825. 1822. Asaphus, Bronqniakt. Hist. Nat. Crust. Fossiles. 1S2"). Homalonotus, Kcenig. [cones foss. sectiles. 1S25. Asaphus, Deslongchamps. Men.. Sue. Linn, du Calvados. L828. Asaphus, Dalman. Vet. Acad. Arsberatt. 1S32. Dipleura, T, Ireen. Monog. Trilob. X. America. 1S35. Homalonotus, Bronn. Lethsea Geognostica. 1S37. Trimerus, Green. Amer. Jour. Science. L839. Homalonotus, Emmrich. De, Trilob. Dis 1S30. Homalonotus, Murchison. Silurian System. 1840. Homalonotus, Milne-Edwards. Hist. Nat. Crustaces. 1840. Homalonotus, Bronn. Leonhardt's Jahrb. fiir Min. 1841. Homalonotus, Phillips. Palaeoz. Foss. Cornwall, Devon and Somer et. 1S42. Dipleura, Conrad. Jour. Acad. Nat. Sci. 1842. Homalonotus, D'Archiac and Da Verneoil. Trans. Geol. Soc. 1542. Dipleura, Vanoxem. Rept. Third Dist. N. Y. L843. Homalonotus, Dipleura, Hall. Rept. Fourth Dist. N. Y. 1843. Dipleura, Hi ;, Goldfdss. Neues Jahrb. fur Min. 1543. Homalonotus, Castelnau. E^s. sur le Syst. Sil. hore el < tonstantinople. juart. .lour. Geol. Soc. 1866. Homalonotus, D'Archiai . Pischee ami Dm Vbrneoil. In Tchihatcheff's Asie Mineure. i i] te rendus. L867. B ■ Etheridgb. Quart. J ■. Geol. Soc. Prodr. d. descript. ge"ol. de Belgique. . . :•] Woodward. Monog. Brit. Trilobites. IsT'J. // , Barrakde. Syst. Sil. Bohfime, vol. i, suppl. 1n7:i. Homalonotus, Washburn. Amer. Jour. Science. 1^7.". H s, II''.. i and Rathbun. Ann. Lye. Nat. Hist. ;; . [llustrations of Devonian Fossils. 1876. // . ■' ' ; .'. RffiMER. Lethsea palseozoica. 1S7<. // . Av.m.in. Palaeontologia Scandinavica. 11ml. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist. L879. Hi B in's Class, u. Ordnung. der Thierr., vol. v. 1881. il .1:1111. Zeitschr. d. deut. geol. Gesellsch. 1881. Ho Ball. Eleventh Rept. Geol. Surv. Indiana. 1881. Homalonotus, Woodward. Geol. -Mai'-., vol. viii. 1882. Homalonotv . Geol. Mag., vol. ix. B '. is. Rech. sur les Terrains anc. des Asturies el de la Galice. i nog. llomal. Art. Rhein. Unterdev. ■/Ins, Novak. Zur Kenntn. bohm. Trilob. 1884. Hi s. Novak. Studien an Hypost., ii 1884. //" . Beushadskn. Oberharz. Spirif. Sandstn. 1885. /'' Whitfield lull Am. Mus. Nat. Hist., No. ti. i -v"'. //' •■ i.Li.r. Proc. Geol. Assoc, and Ann. de la Soc. g6ol. du Nord. L886. II . 'I Fau liein. Unterdev. 1886. // , Gossi let. Ann. de la Soc. gdol. .In Nord. Homalonotus, Barrois. Bull.delaS0c.g60l.de France. 1886. Homalmi . I 1 1;. Bull, de la Soc. geol. de France. Diagnosis. Body usually la rge, produced, depressed above, with abruptly sloping sides. Axial furrows indistinct or obsolete. Surface smooth or spinose. Wow depressed-convex, wider than long; genal .•lilies rounded: anterior margin somewhat pro- duced; glabella sub-rectangular, smooth or with fainl lateral furrows; eyes small, situated somewhat back of the middle of the shield ; the facial sutures run from the genal angles over the eyes, converging toward the frontal margin, where they are connected by the transverse frontal SYNOPSIS OF GENERA. xxv suture, thence they continue to the edge of the doublure, where they meet, thus inclosing a small, free, sub-triangular plate. I composed of thirteen deeply sulcate segments. Pygidium smaller than the cephalon, elongate-trian- gular, posteriorly rounded or slightly produced. The axis hears usually from ten to fourteen annulations. Pleurae smooth, or with posteriorly sloping ribs. Family, Bronteid.2e. Genus B R 0 N T E U S , Goldfuss. L843. 1821. Entomostracites, Wahlenberg. Nov. Art. Soc. Sci. Upsala. 1S22. Asaphus, Brohgniart. Hist. Nat. Crust, f 1823. Asaphus, Schlotheim. Nacht. ii, zur Pelrefakten. 1S26. Asaphus (llksnus), Dalman. Lleber Palseaden. 1881. Asaphus, Steiningeh M6ra. S i Franc 1S32. Olenus, Goldfuss. Dechen's Handb. der Geognosie. 1S3H Asaphus (Olenus), Murchison. Silurian System. 1839. Asaphus, Emmrich. De Trilob. I'i 1839. Brontes, Goldfuss. Nov. Act. Acad. N. C. lSlii. Brontes, Mi bnster. Beitr. iii. zur Petrefaktenkunde. 1840. Brontes, Sedgwick and Murchison. Trans. Geological Society. 1841. Goldius, De Koninck. Nouv. Mem. de l'Acad. roy. de Bruxelles. 1841. Brontes, Phillips. Pal. Foss. Cornwall Devon and Somerset. 1842. Brontes, D'Archiac and Db Verneuil. Trans. Geological Society. 1812. Brontes, Muenster. Beitr. V, zur Peti'efaktenkunde. 1843. Brontes, F. A. Rcemer. Verstein. des Harzgeb. 1843. Br onteus (Brontes), Goldfuss. Neues Jahrb. fur Min. lS-iy. Bronteus, Burmeister. Organiz. d. Trilob. 1843. Brontes, Portlock. Geol. Rept. 1. londei'ry. 1844. Brontes, Sedgwick and Murchison. MM. PalSoz. Gebilde im Nord. von Deutschl. und Belgien (Leonhardt). 1S45. Bronteus, Emmrich. Neues Jahrb. fur Min. 1S45. Bronteus, Murchison, De Verneuil and Keyserling. Russie et Oural. 1845. Bronteus, Beyrich. Deb. bohm. Trilob. 18415. Bronteus, McCoy. Syn. Sil. Foss. Ireland. 1846. Bronteus, Barrande. Not. prelim, sur le Syst. Sil. Boheme. lS4u. Bronteus, Beyeich. Dntersuchungen iil>. Trilob. II. 1846. Brcmteus, Logan. Rept. Geol. Surv. Canada. 1S47. Bronteus, Corda. Prodrom. Moo. bohmischen Trilobiten. 1850. Bronteus, McCoy. Ann. and Mag. Nat. Hist. 1850. Bronteus, the Brothers Sandberger. Verst. d. Rhein. Sch. 1S52. Bronteus, Hall. Pal. N. V., vol. ii. 1852. Bronteus, Barrande. Syst. Sil. Boheme, vol. i. 1852. Bronteus, F. A. Rcemer. Beitr. ii, zur Harzgeb. 1855. Bront( us. P. A. Rcemer. Beitr. iii, zur Harzgeb. 1857. Bronteus, Billings. Rept. Prog. Geol. Surv. Canada. 1858. Bronteus, Giebel. Silur. Fauna Unterharz. XXVI SYNOPSIS OF GENERA. L859. is.;,; 1-71. 1876. 1877. L878. L878 1878. 1-7.'. 1-71'. 1883. 1884. 1884 1885. L885. 1885. 1887. 1888. 1888. Pal. V V., vol. iii. . McCoy. Synops. Sil. Poss. Ireland. Dev. and Silur. Foss., Square Lake, Maine. ( '.-,i. Silur. Foss. A.nticosti. . p \ !:.i m k. Beitr. v zur Harzgeb. Hall. Twentieth Rept. N. Y. State Cab. Nat. Itist. iskissent. Kssai sin- l:i g6ologie de hi Manche. . Babraxde. Syst. Ml. Bohfime. vol. i. Suppl. Gosselet. Bull. de l'Acad. roy. de Belgique. \ts, Tkomelin and Lebescoste. Bull. Soc. g6ol. de Prance, s, Rcemer. Lethaea palseozoica. I [] 1 1\ and Grasset. Assoc, francais Avanc. Si .Whitfield, inn. Rept. Geol. Surv. Wisconsin. Expl. Carte g6ologique de France, Atlas. . Katser. Fauna a-lt. Devon. Abl. d. Harzes. . Katser. Zeitschr. der deutsch. geol. Gesellschaft. , S i >;:. stiuiiin an Hj postomen, i. ■ .-■. Whitfield. Geol. Wisconsin, vol. iv. Novak. Zur Kenntn. bobm. Tiilob. Neues Jahrb. fiir Min. Studien an Hypostomen, ii. Hull. < 1 * ■ la Soc. d'Etudes Scientif. d'Angers. Ann. Soc. geol. du Nord. Kalke von Waldgirmes. Handb. d. Palaeontologie. Ann. Soc. geol. dn Nord. rnychew. M6m.Comit6.g6ol. Brontes, Frech. Zeitschr. der deutsch. geol. Gesellschaft. Pehecku. Zcit.scln-. dm- ili'utsch. geol. Gesellschaft. , I ! IRKE. '■ \ts, CEhlert. Bronti us, B (8, M U'KKK. 0S, ZlTTEL. Diagnosis. Body broadly oval. Cephalon semi- circular, with sharp, often somewhat produced genal angles. Glabella closely appressed to the cheeks, broad anteriorly and extending to the frontal mar- gin. Lateral furrows indistinct or obsolete. The facial sutures begin on the posterior margin, and in trout of the eyes run nearly parallel to the margin of the glabella, being con- tinuous on the frontal margin. Eyes lunate, homocorneal, and situated some- what posteriorly. Thorax slightly larger than the cephalon, and composed of ten segments, which upon the pleurae are simple and sharply pointed. Pygidium very large, depressed-convex, paraholic in outline, with a very short sub-triangular axis. The pleurae each hear seven or eight simple ribs, arranged on each side of a larger median simple or compound rib. SYNOPSIS OF GENERA. xxvii Genus PHACOPS, Emmrich. 1S39. 1770. Echinitts, Zeno. Neue Physik. Belustig. vol. i. 1822. CaZy i . Brongniart. Hist. Nat. Crust. Foss. 1823. !' Schlotheim. Nachtr. ii, zur Petref. 1 -J4. Calymt te, Hcbninghaes. Noggerrath's Rheinl. u. Westphal. and Isis 1825. Cat; vn. Leonhardt's Zeitsch. Min. 1525. Tn' . - verhand. d. Vaterl. Mus. 1526. Calymene, Dai.max. Ueber Palseaden. 1831. ' . Steininger. Mem. S _• 1.1 1832. ' ldfdss. Dechen's Handb. d. G L832. Cah . •■ . BH. Mm. Trilob. X. America. 1S35. I . 11k. ..\x. Lethaea geognostica. 1S37. Calymene, Bockland. Bridgewater Treatise. 1S37. Trilobites, Qoexstedt. Wiegmann. Arcbiv. 1838. /' ;t Sars and Boeck. Gsea Norvegica. 1839. ( . Mdrchison. Silurian System. 1539. Phacops, Emmrich. De Trilob. Diss 1840. Calymene, Sowbrby. Trans. Gei 1 % S iety. 1840. i , Eichwald. Urwelt Russlands. 1840. Calymene. Mdenster. Beitr. iii. zur Petrefaktenkunde. 1540. Calymene, M;i.ne-Edwards. Hist. Nat. Crust. 1S40. Phacops, VON Bech. Beitr. zur Geol. Russian. Is. 1841. Calymene, Phillips. Pal. Foss. Cornwall, Devon, and Somerset. 1542. ' . D'Ahchiac and De Verneuil. Trans. Geol. Soc. Lond. 1842. Calymene, Muekster. Beitr. zur Petrefaktenkunde. 1843. PI," ifcss. Neues Jahrb. fur Min. 1543. Calymene, Asaph us. F. A. Rxemer. Verst. des llarzgeb. ]n43. Phacops, Bubmexsteh. Organiz. der Trilobiten. 1S43. Phacops, Portlock. Rept. Geol. Londonderry. 1543. Calymene, Hall. Rept. Fourth Dist. X. Y. 1544. Phacops, C. F. Rcemer. Rhein. Uebertrangsgeb. 1S44. Calymene, Owen. Geol. Expl. Iowa, Wis., 1 1845. Phacops, Emmrich. Neues Jahrb. fur Min. 1845. Phot ps, Murchison, De Yerxeuh. and Keyserling. Russie el Oural. 1*46. Portlockia, McCoy, Silur. Foss. Ireland. 1S46. Phacops, Geimtz. Grundr. der Verstei 1846. Phacops, Pictbt. Traite" Elem. de Palebnt. 1846. Phacops. Bakraxde. Notice prebm. an 1 Nouv. Trilob. 1S48. Phacops. Salter. Mem. Geol. Survey Unit.-.! King 1840. Phacops, Richter. Pal. des Thiiringerwaldes. 1850. Phacops, the Brothers Saxdberger. Verst. d. Rhein. Sch. Syst. 1850. Phacops, Portlockia, McCoy. Ann. and Mag. Nat. Hist. 1850. Phacops, De Vebhedtl. Bull. Soc. geol. 1. Portlockia, McCoy. Synop. Pal. Foss. Woodwardian Mus. 1851. Phacops, McCoy. Synop. Pal. Foss. Woodwardian Mus. 1852. Phacops, Barraxde. Syst. Sil. d. Boheme, vol. i. 1S52. Phacops, F. A. Rojmer. Beitr. ii zur Harzgeb. 1853. Phacops, Geixitz. Gramvackenf. Sachsen. xxviii SYNOPSIS OF GENERA. 1S54. P and Zeilkr. Verhandl. der Naturhist. Vereins. 1854. Cal ■ - M<5m. Si e. ge"i I. de Prance. L85; s, F. A Ri tr. ii zur Harzgeb. Beitr. zur Palaont. des Thiiringerwaldes. IS5S Silur. 1 ma Unterhai-z. 1859. P • ' i • Pal. N. Y.. vol. iii. ■ ntsch. geol. Gesellschaft. Naturalist ami l ica. . I l.u.i. . Descr. Nov, sils. 1862 . Hellhann. 1> len Thiiringens. Neues Jahrb. fur Min., etc. 1862. Iai "u Rept. N. V. State Cab. Nat. Hist. der deutsch. geol. Gesellschaft. . Billings. Dev. ami Silur. Fossils Square Lake, M g. Brit. Trilobil ■ I. deutsch. geol. < fesellschaft. . F. A. Ra tr. v zur Harzgeb. lsp;7. Phacops, Etherid ir. Geol. Si . I ' ■ - ' rlllS. 1868. , Meek and Worthen. Geol. Surv. [11., vol. iii. 1868. Phacaps, Dewalque. Prodi', d'une Descript. ge"ol. de Belgique. 1870. Phacops, TrBTZE. Devon Schicht. Ebersdorf. lsTj. Phacops, Kayser. Zeitschr. der deutsch. geol. Gesellschaft. 1872 Phi Syst. Sil. Bohfime, vol. i. Suppl. Is; in. Etudes ge"ol. sur le Bosphore. 1^7::. Phacops, Nicholson. Palseontol. Ontario. 1874. /" Steinhardt. Die bis jetzt in preuss. Geschieb. gef. Trilob. IsTa. Phat . Macrer Neues Jahrb, fur Min. 1876. Phacops, 11 ml. Illustrations of Devonian Fossils. lsT'i. /'. i Neues Jahrb. fur .Min. 1876. Phacops, C. I-'. Rcemer. Lethaea pala 1879. /' i;. Studien an Hypostomen, i. |sm>. Phacops, von Kcenen. Neues Jahrb. fur Min. 1881. Phacops, Kayser. Jahrb. der Konigl. preuss. Landesanst und Bergakad. 1881. Phaco} , Schmidt. Rev. Ostbalt. Trilob., pt. i. 1882. Phacops, Whitfield Geol '■ i, vol. iv. i^s'-'. /' rrois. Rech. sur les Terrains anc. d. Asturies et de la Galice. I'n!. Eureka Dist. 188 1. /" i rke. 1 berger Kalk. 1884. Pha< p . Nov u;. Studien ,,, ii, lvsl 8 Silur. und devon. Geschieb. Westpreuss. 1885. . Maurer. Kalke von VValdgirmes. 1885. Phacops, Zittel. Handb. d. Palseontol ■ Barrois. .1' i. du Nord. 1885. /' (Eiilert. Bull, di Etudes Scientif. d'Angers. , Waldschmidt. Dev. Schicht. Gegend Wildungi lss">. /' i iccesi 1 0 io Co. 1. .In Nord and Hull. Soc. geol. de France. M i rdev. / * ops, M l)n :hschiefer von Serleburg. Phacops, F■;. Bulletin Denison University. SYNOPSIS OF GENERA. XXIX LSS7. Phacops, CEiilert. Ann.de la S logiqne. L88S. Phacops, Frech. Zeitschr. der deutsch. geol. Gesellschaft. Diagnosis. Body oval. Cephalon parabolic; genal angles obtuse, or produced into minute spines. Glabella tumid, prominent, widest ante- riorly; the two anterior pairs of lateral furrows indistinct. Eves very large, conspicuous, bearing numerous corneal lenses. Thorax sub-quadrate ; segments eleven ; pleura' arched, and rounded at their extremities. Pygidium moderately large, composed of few annulations; margin entire and not pro- Longed into a terminal spine. Genus DALM A N I T E S , Barrande. 1852. 177'-'. EntomoHthus, Born. Lithoph. Bornimi. 1781. Trilobus, Brdennich. Kjoben. Sellsk. Skrivter. Nye Samml. 1794. EntomoHthus, Redss. Mayer's Samml. phj Uifs. 1811. Trilobitts, Parkinson. Organic Ri 1821. Entomostracites (partiin), Wahlenberg. Nov. Act. Ui>sala. 1822. Asaphus, Brongniart. Hist. Nat. Crust, foss. 1823. T>-tlobites, Schlotheim. Nachtr. ii zur Petrefakt. 1S25. Trilobites, Sternberg. Verhandl. des Vatarl. Mi 1826 Asaphits, Dalman. Oeber Palseaden. 1829. Asaphus, Holl. Handb. der Petrefacten. 1S32. Asaphvs, Eaton. Geological Text-book. 1832. Asaphus, Goldfuss. Dechen's Handb. der Geognosie. 1832. Asaphus, Green. Monog. Trilob. X. America. 1835. Asaphus, Green. Sin pi. Monog. X. Amer. Trilob. ls:;7. Asaphus, Hisinger. Lethjea Suecica. ls:;7. Asaphus, Bbckland. Bridgewater Trei 1>M7. Asaphus, Quenstedt. Wiegmann. Arcl LS39. I aphus, Calymene, Murchison. Silurian System. 1839. Phacops partim, Emmrich. De Trilob. Di 1840. Asaphus, Milne-Edwards. Hist. Nat. Crust. 1840. Phacops, von Buch. Geb. Format. Rnsslands. 1841. Asaphus, Aspidolites, Conrad. Fifth Ann. Rept. Pal. N. Y. 1S43. Asaphus, Hall. Rept. Fourth. Dist. N. Y. 1843. Asaphus, Goldfuss. Neues Jahrb. fur Min. 1843. Phacops, Burmeister. Organiz. d. Trilobiten. 1843. Phacops, Portlock. Rept. < I. Lond lerry. 1845. Dalmania, Emmru h. Neu ■■ Jahrb. fur Min. 1845. Phacops, Asaphus, Mdrcmson, De Vei i Keyserli 1846. Phacops, Geinitz. Gi-undr. der Versteinerui 1846. Phacops, Barrande. Notice pr Hellmann. Die Petrefacten Thiiringens. IS62. Dalmania, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist. , McCoy. Synops. Silur. Foss. Ireland, id, Billings. Dev. and Silur. Foss. Square Lake, Mam.'. 1863. Dalmania, Hall. Transactions Albany Institute. L864. Phaeops {Odontoehile), Salter. Monogr. Brit. Trilobites. 1865 Dalmania, Meek and Wokthen. Proc. Acad. Nat. Sci. Phil. 1867. Dalmania, Hall. Twentieth Rept. N. Y. State Cab. Nat. Hist. 1868. Dalmanites, Dewalqi b. Prodrom. d'une Descrip. gciolog de Belgique. 186S. Dalmanites, Meek and Worthen. Geol. Surv. HI., vol. iii. 1869. ■'. Haidekhain. Zeitschr. der deutsch. geol. Gesellschaft. 1869. Phaeops, Ltnnarsson. Vestergoth camb. och. silur. Afiag. 1871. Dalmanites, Meek. Proc. Acad. Nat. Sci. Phil. 1s7j. Dalmanites, Barrande. Syst. Sil. Boh6me . vol. i. Suppl. |stj. Dalmanites, Meek. Am. Jour. Science. 1^7:;. Dalmanitts, Meek. Geol. Surv. Ohio, Palseont. vol. i. 1874. Phaeops [partim), Steinhardt. Hi'' bisjetzf in pieuss. Geschieb. gef. Trilobiten. |s7." Dalmania, Hartt and Rathbdn. Ann. Lye. Nat. Hist. 1875. Dalmania, 11 m.i. and Whitfield. Geol. Surv. <»hio, Palaeont. vol. ii. 1876. I ' F. Rcembr. I ica. 1876. Dalmanites, Hall. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist. 1876. Da Hall. Illustrations of Devonian Fossils. |s7>;. Dalmanites, Barrett. Am. Journ. Science. 1877. Dalmanites, Meek. Geol. Expl. Fortieth parallel. IsTs. Dalmanites, Kayser. Fauna 'I. selt. Devon.-Ablag. Ilarz. i«, Angelin. Palaeontol. Scandii 1879. Do Novak. Studien an Hypostomen, i. 1879 Dalma lites, v. Thirty-first. Rept. N. V. State Mus. Nat. Hist. 18s< ; i.-- Zeil chr. .1. deutsch. geol. Gesell chaft. 1881. Dalmanites, Schmidt. Revi ion Ostbalt. silur. Tnlob. 1881. Dalmanites, Mi i ihini. Roy. Academia dei Lincei SYNOPSIS OF GFNER I XXXI 1883. Dabnanites, Novak. Zur Kennt. bohm. Trilob. 1SS4. Dtii mil ii lbs, Novak. Studien an Hypostomen, ii. 1884. Dahnanites, Walcott. Palseontol. Eureka Dist. 18S5. Dahnanites., Clarke. Geol. Su sion in Ontario Co. 18S5. Dahnanites, CEhlbht. Bull, de la Soc. d'Etudea Scientif. d. Angers. L886. Dahnanites, Barrois. Bull, de la Soc. giol. de France. 1887. Dahnanites, Fosrstb. Bull Denison. Univ. The species of the genus Dalmanites frequently exhibit a tendency to varia- tion in many of their more important features. This variability may be either in the relative development of the lateral glabellar furrows, the coalescence of the glabellar lobes, or in the ornamentation of the margins of the cephalon and pygidium ; the features of the glabella are of more distinctive importance, the ornamental characters undoubtedly being of a somewhat more fugitive value. By the unequal development and suppression of the glabellar lobes and furrows, there is an evident transition from the typical Dalmanites to the typical Phacops. Again, the gradual coalescence of the lateral glabellar lobes produces forms following the type of the genus Chnsmops, in which the first two pairs are united, and of the genus Monorakos, in which the three lobes of each side are coalesced. The ornamental features are of importance in the establish- ment of subordinate groups of a provisional character. It is here proposed to group under the term Hansmannia the typical and unvaried forms of Dalmanites which follow the type of D. caudatus, (Briinnich) Emmrich, and I). Hausmanni, Brongniart. Sub-genus H A U S M A N N I A ; Diagnosis. Body elongate-ovate, depressed- convex. Cephalon lunate ; genal angles produced into spines; glabella scarcely prominent; frontal lobe transverse or sub-rhomboidal ; all the lateral lobes well developed. Thorax composed of eleven segments; pleurae beveled, the posterior segments often produced. Pygidium large, bearing more than eleven ampliations; margin entire, often pro- duced into a caudal spine. The Devonian species, which are referred to this group, are to some extent imperfectly known, and it may eventually N. S.-G. XXXI 1 SYNOPSIS OF GENERA. become necessary to place such as arc now known only from pygidia other association. Sub-genus CORONURA, n. s -g. Diagnosis. Pygidium large, bearing along its lateral margins a row of long, cylindrical, acute and gently recurved spines. The posterior ex- tremity is crescentic, its margin being smooth or furnished with a row of erect spines. Annulations numerous. in some Sub-genus CRYPH.1US, Green. 1837. I1-:','-'. Asaphus, Green. Monog. Trilob. N. America. . i sger. Mem. Soc. geol. de France. 1835. ( 'nhjii '■"'■ Hceninghaus. Litt. Lithograph. L835. Asaphus, Leonhardt's Jahrb. f. Min. ]^:;T. Cryph&us, Green. Amer. Jouiti. Science. ',./'.'. Conrad. Second Aim. Rept. Pal. N. V. 1840. . ■ Milne-Edwards. Hist. Nat. Crust. 1842. Oletms, D'Ari hiac ami De Verneuil. Trans. Geol. Soc. 1843. ,: Leonhardt's Jahrb. fiir Min. 1843 '. Hall. Rept. Fourth nist. N. Y. 1843. P Us, I" A. Rojmer. Verstein. d. Harzgeb. 1844. Oh >ius, D'Archiac and De Verneuil. JElt. palseoz. Gebilde im Nord. von Deutschl. und Belgien. 1844. /' iiracanthus, C. F. Rcemkr. Rhein. Uebergangsgeb. L846. Cryphaeus, Rouault. Hull. soc. geol. de France. 1846. Phacops, er. Organ, d. Trilobi 1847. Asteropyge, Meta antlms, Corda. Prodrom. Mon. bohm. Tril. 1849. CrypltOBiis, McCoy, (non <'r>i/>/,s. Green). Ann. Mag. Nat. Hist. 1850. Pliacops, ' heirurus, V. A. Rcemer. Beitr. i. zur Harzgeb. 1850. CrypTiwtis, De Verneuil. Bull Soc sjeol. de France. Phacops, the Broi i rgi is. Rhein. Schicht. Syst. Cryphwus, Dk Bull. Soc. geol. de France. I-."l I Zeilkr. Verhandl. des Naturhistor. Vereins. '. Richter. Beitr. zur Palseontol. des Thuringerwaldes. 1861. Dalmania, Hall. i Rept. N. Y. State Cab. Nat. Hist. 1864, /' Salt] Monog Brit. Trilobites. [Ac, Fischer and Dk Verneuil. In Tehihatcheff 's Asie Mineure. . I-'. A. RfflMER. Beitr. v. zur Harzgeb. ■. De Verneuil. Comptes rendus. Ethkridge. Quart. Jour. G iol. Soc. 1868. /'/• uracanthus, I > v. ilque. Prodrom. d'une Descrip. geolog. de Belgique. idullah. Etude geol. . ur ■ i ! phore. SYNOPSIS OF GENERA. XX X 111 1876. Da! ma n it' 1876. ( 'ri/plm us. L878. Crypha us. 1879. Cryp 1SS1 1 1SS3. . IS84. i.ll is. 1 S85. 1 1S86. phcBus, 1886. Crypha us. ■i. Hall, Illustrations of Devonian Fossils. ('. F. Rckmkr. Lethsea palseozoicn. Kaysek. Abhandl. / Specialkarte Pr. und il. Thiir. St. •. Zeitschr der deutsch. geol. Gesellschaft. Schlgeter. Sit/.ungsb. niederrb. Gesell. Bonn. Katser. Jahrb. der Konigl. Preuss. geol. Lan lesanst. und Bergakad. hausen. Abhandl z Specialkarte Pr. und d. Thiir. S Zittbl. Handb. d. Pateontologie. Madrer. Fauna rechtsrhein. tlnterdev. Matuschka Dachschiefer mrsr. Diagnosis. Genal angles produced into long, often laterally compressed and narrow spines. Posterior thoracic segments produced and acute. Pygidium with five annulations and five pairs of marginal lubes or spines. Terminal lobe more or less developed. Sub-genus 0 DON TOO E P H A L U S, Conrad. L840. 1832. Asaphns, Eaton. Geological Text-book. lSo'2. Ciili/iiinn . Green. Mon. Trilob. N. Americ 1840. Odontocephalus, Conrad. Third Ann. Rept. Pal. N. V. IS42. Oa . Vanuxem. Geol Rept. Third Dist. N V. 1843. ■ ephalus, Hall. Geol. Rept. Fourth l>i>i. Nr. V. 1845. Odontoci pita 'us, Kmmrich. Leonhardt and Bronn's Neues Jahrb. fiir. Miu. 1861. Dai i'.n. Fifteenth Rept. N. Y. State Cab Nat. Hist. I8l 5. Odonti . Meek and Wohthen. Geol. Surv. Illinois, vol. iii. 1^7'i. Dalmanites, Hall. Illustrations of Devonian Fossils. 18S5. Odonto ■ . Zittel. Handb. a. Palseontologie. Diagnosis. The frontal border of the cepha- lon bears a series of incisor-like denticulations, which lie in contact at their distal extremities. These are longest in front and become obsolete about half way from the anterior extremity to the tips of the genal spines. Pygidium usually with two more or less developed terminal spines XXXIV SYNOPSIS OF GENERA. Sub-gencS CORYCEPHALUS, n. sub-gen Diagnosis. The entire frontal and lateral margins of the cephalon bear a single row of widely separated denticulations, which may be acute and triangular or broad and sub- quadrate. Sub-genus CHASM OPS, McCoy. 1850. 1837. Asaphus (partim), Murchisoh. Silurian System. I83S. Trilobites (partim), Sars and Bokck. Gaea Norvegica. 1843. Phacops (partim), Portlock. Geolog. Rept. Tyrone. 1845. PJiacops [partim), Emmrh h Neues Jahrb. fur Min. 1846. Phacops (partim), Bdrmeister. Organiz. Trilobites. 1848. Dalmania, Sai ikii. Mem. Geol. Suit, United Kingdom. 1849. Phacops partim), Salter. Mem. Geol. Surv. United Kingdom. 1850. Chasmops, McCoy, bin. and Mag. Nat. Hist. [851. Chasmops, Odontochile, McCoy. Synops. Pal. Poss. Woodwardian Mus. 1852. Chasmops, Angelin. Palseontologica Suecica. 1853. Phacops (Dalmania), Salter. Geol. Surv. Decade vii. 1864. Chasmops, Salter. Monogr. Brit. Trilobites. 181 I. Phacops (partim), Linkarshok. Verstergotl. camb. oeh. siltir. Aflag. 1^71. Phacops [partim), Steinhardt. In preuss. Geschieb. get'. Trilobit. 1876 Dalmanites (partim), Hall. Illustrations of Devonian Fossils. |s7i;. Chasmops, C. F. Rcemkr. Lethaea palseozoica. ]s7s Phacops (partim), Angelw. Paljeontologia Scandinavica. 1885. Chasmops, Zittel. Handb der Pala tologie. Diagnosis. Genal angles usually produced into spines. Frontal lobe of the glabella large, trans- verse and not intersected by the facial sutures. Lateral lobes unequal, the first and second pairs being coalesced and the third pair nearly obso- lete. Pygidium large, sometimes with a terminal -pine. SYNOPSIS OF GENERA. Family, Acidaspiime. Genus ACIDASPIS, Mtjrciiison. 1839. 1838 ' , Warder. Amer. Jour. Sci •• 1838 I a, Aothony. Amer. Jour. Science. LS 19. Addaspis, Murcuison. Silurian System. 1839. Ai-f/m (partial), Goldfcss. Nov. Act. Caes. I p • is;j;i. Odontophura, Emmrich. De Trilob. Dissert. 1840. 2 M Beitr. iii znr Petrefaktenkunde. 1840. Addaspis, Milne-Edwards. Hist. N st., vol. iii. 1S4H. Addaspis, Acantholoma, Conrad. Third Ann. Kept. Pal. N. V 1841. Du ra rus, Conrad. Fii R ' N. 1 1S43. Ceraurus, Locke. Amer. Jour. Science. ls43. Bronteus [partim), P. A. Rcemer. Verstein. Harzgeb. 1S43. Arges (partim), Odontopleura, ' • N Jahrb. fiir M ls43. Odontopleura, Bubmeister. Organiz. d. Trilob. 1844. Odo . Arges, C. F. Rcemer. Rheiniscb. Ui bergangsgeb 1S45. Odontophura, Emmrich. Neues Jahrb. fiir Min. 1845. Ceraurus, Loves. Ofvers. of. Kongl. Vetensk. Akad. Forhandl. 1846. Addaspis, McCoy. Synopsis Silur. Fuss. Ireland. 1846. Odontopleura, Barrandb. Notice prelim, sur Syst. Sil. Boh&me. 1846. Odontopleura, Geinitz. Grundriss ss. Ireland. 1862. Adda pis, Hellman. Die Petrefacten Tburingens. 1S62. Addaspis, Hall. Geol. Surv. Wisconsin. 1863. Addaspis, Richter. Zeitschr. der deutsch. geolog. Gesellschaft. 1866. Addaspis. F. A. RcesIer. Beitr. v, Harzgeb. 186S. Addaspis, Meek ami Worthen. Geol. Surv. Illinois, Pal.. \"1. iii. 1869. Addaspis, Ldhtabson. Vestergotl. cainb. och. silur. Aflag. 1872. Addaspis, Barrande. -Syst. Sil. Boheme, vol. i. Suppl. 1^73. Addaspis, Meek. Geol. Ohio, Palaeontology, vol. i. 1875. Addaspis, Miller. Cincin. Quart. .lour. Science. 1876. Addaspis, C. F. Rcemer. Lethsea pabsozoica. XXXV X XXV) SYNOPSIS OF GENERA. IS77. W :i. Twenty-ninth Rept. N. Y. State Mus. Nat. Hist. Is;.. , I telt. Devon. A blag, ties Harzes. 1379, .. Hall. Trans. Albany Inst., and Twenty-eighth Kept. N. V. State Mas. Nat. Hist. [S7<1. Acidaspis, Walcoti Thirty-first Rept. N. V. state Mus. Nut. Hist. is: lis, Noi Studieti an Hypostomen i. 1881 -. Hall. Eleventh Ann. Rept. Geol. Surv. Indiana. I^s;;. Acidaspis, Novak. Zur Kennt. bohm. Trilob. |ss|. .1 . Novak. Studien an Hypostomen ii. Ins.". , Zittbl. Handb. d. Palaeontologie. lss;, - .'-in. i'. Revision d. Ostbalt. Silur. Trilob. IS87. Acidasp . I brste Bulletin Denison Qniversity. Diagnosis. Body depressed-convex. Sur- face ornamented with numerous spines. indistinctly trilobate, with two longitudinal furrows crossing the glabella, produced by the union of the inner ex- tremities of the three pairs of lateral fur- rows. Occipital ring conspicuous. Thorax with from nine to ten segments, each one hearing a strong, nonsulcate ridge on the pleurae, which is produced into a long, hollow spine. Pygidium short, sniall; axis bearing from one to three annulations, and the pleurte usually but a single one. Margins spiniferous. Family, Lichad.e. Genus L1GHAS, Dalman. 1826. 1821. racites, Wahlenberg. Nova Acta Soe, Sci. CJpsala. 1822 Trilobites,S hlotheim. Nachtr. iii zur Petrefacktenkunde. 1822. Pamdoxides, Biiosghiart. Hist. Nat. Crust. Fossiles. 1825. Pari ides, Bigsby. Jour. Acad. Nat. Science. Asapkus, Dalman. Ueber Palaeaden Ueber Palaaaden. 1828. Ampyx, Dalman. Ai'sberatt. 1829. Lichas, lb. 1.7.. Handbuch der Petrefacktenkunde. |v;:; P> ''■■ ides,G Monograph of the Trilobites of Noi-th America. 1835. Lichas, Bronx. Letha:a geognostica. • n soeb Lethrea Si ica. '••■■•• Rept. Pal. N. V. l-:;;i Arges, Goldi i Nova la i.cad. C. !... \1\. 1s"1 I' - Mn m ln« w:i>- Hi 1 Nat I 'in taces. 1842. Asaphus, Ci mi. Jour. Acad. Nat. Science. 1842. Arges, D'Archiac a rnkuil. Trans. Geol. Society. SYNOPSIS OF GENERA. xxxvii IS-1'J. Metopias, Eichwald. Urwelt Russlands. 1843. Metopias, Eichwald. Beitr, zur Kenntn. d. Russ. Reichs. L843. Metopias, Leuchtenbbrg. Thierrest. des Urwelts. 1843. Paradoxides, Goldfdss. Neues Jahrb. fur. Min. 1843. A retiniirus, C lstblnad Essai sur le Syst. Sil. de l'Amerique Septentrionale. 1843. Platynotus, Hall. Geol. N. V.. Rept. Fourth District. L843. Lichas, Bcrmeister. Organization der Trilobiten. IS43. Nuttainia, Poktlock. Geolog. Rept. Londonderry, etc. 1844. Asaphus, Eichwald. Silui-sch. Esthlands. ism. Arges, D'Archiac and De Verneuil. Die aelt. palaiozoisch. Gebilde im Norden von Deutschl. u. Belgien. 1845. Nuttainia, Emmrich. Neues Jahrbuch fur Min. 1845. Liehas, Loves. Ofversigt af Kongl. Vetensk. Akad. Forhandl. 1545. Lichas, Beyrich. (Jeber bohm. Trilobiten. LS45. Calymene, Morchison. Quart. Jour. Geol. Soc. 1546. Lichas, Barrande. Notice prelim, sur le Syst. sil. Bohgme. 1846. Bronteus (partim), Barrande. Notice prfilim. sur 1.- Sy~t. sil. Bohfime. 1846. Trilobites (partiiii), Barrande. Notice prilim. sur 1'- Syst. sil. Boheme. 184ti. Lichas, Beyrich. Untersuchungen ueber die Trilobiten. 1846. Arges, Beyrich. Untersuchungei ber die Trilobiten. 1 > 1 7 . Calymene, McCoy. Silurian Foss. Ireland. 1 ^ 17. Corydoeeplialus, Corda. Prodrom Monog. bohmischen Trilobiten, 1847. Dicranopeltis, Corda. Prodrom Monng. bohmischen Trilobiten. 1847. Aeanthopyge, Corda. Prodrom Monog. bohmischen Trilobiten. 1 s -i 7 . Dieranogmus, Corda. Prodrom Monog-. bohmischen Trilobiten. 1847. Platynotus, Hall. Palaeontology N. Y.. vol. i. 1848. Lichas. Salter. Mem. Geol. Surv. United Kingdom. 1S49. Lichas, McCoy. Ann. Mag. Nat. Hist. 1850. Lichas. Fletcher. Proc. Geol. Society. 1852. Lichas, Barrande. Syst. Sihir. du Centre de la Eohfime, vol. i. 18.r)4. Lichas. A.N6ELIN. Palseontologia Seandinavica. 1 sr. 4 . Lichas, Eichwald. Grauwacksch. Liv. und Esthlands. 1855. Lichas, Emmons. American Geology. 1857. Lichas, Eichwald. Beitr. zur geogr. Verbreit d. foss. Thiere Russlands. ls.-,7. Lichas, Nieskowski. Archiv. fur Naturk. Liv, Ksth und Kurlands. l.S.'iS. Lichas. Hoffmann. Verhandl. der kaiserl. Mineral. Gesellsch. 1858. Lichas, Schmidt. Archiv. fiir Naturk. Liv. Esth und Kurlands. 1858. Lichas, Dethlepf and Boll. Archiv. d. Vereins d. Freund. d. Naturgesch. in Mecklenburg 1859. Lichas, Hall. Palaeontology N. Y., vol. iii. 1859. Lichas, Nieskowski. Archiv. fiir Naturk. Liv. Ksth und Kurlands. 1800. Lichas. Eichwald. Lethaa rossica. 1861. Lichas, C. E. Ru-jmk.r. Foss. Fauna d. Silur. Diluvialgeschieb. von Sadowitz. 1862. Lichas. Hall, sixteenth Rept. N. Y. State Cab. Nat. Hist. 1S62. Lichas. Hellmann. Die Petrefacten Thiiringens. 1862. Lichas, McCoy. Synopsis Silur. Fuss. Ireland. 1863. Lichas. Hall. Transactions Albany Institute. 1865. Lichas, Wini hell and Mari v. Mem. Boston Societj Nat. Hist. 1865. Lichas, Meek and Worthen. Proceed. Acad. Nat. Sciei 1865. Lichas, Billings. Palaeozoic Fossils, vol. i. 1866. Lichas, Billings. Cat. Silur. Fuss. Anticosti. 1867. Lichas, Hall. Twentieth Kept. N. Y. State Cab. Nat. Hist. 1869. Lichas, Kabstens. Beitr. zur Landeskarte von Schleswig-Holstein. xxxviii SYNOPSIS OF GENERA. 1^7-J. Lichas, Barrandb. Suppl. Syst. Silur. du Centre 'le la Boheme, vol. i. 1872 I- has, Katser. Zeitschrifl der deutsch. gwlog. Gesellschaft. [S74. Lichas, Steixhardt. In preussisch. Geschieb. gef. Trilobiten. I v7 j. Lichas, Billings. Canadian Naturalist and Geologist. js7^ Miller Jour. Cincinnati Soc. Nat. Hist. 1879. / i, . Hall. Twenty-eighth Rept. N. V. State Mus. Nat. Hist. 1880 / , Novak. Sitzungsber. d Kongl. bohm. Gesellsch. d. Wissenschaften. 18S2. /,. Silur. i agen 2 und 3, ira Kristianiageb. und auf Eker. 1884. I i CJndeiBok. ofv. Siljanourad. Trilobit fauna. [S85. Schmidt. Mem. de l'Acad. imp. de St. Petersbourg. 1886. Liclias, Barrois. Ann. de la Societe geol. du Nord. ]s->7. / Foersti Bulletin Denison University. [888. Lichas, Frech. Zeitschr. der deutsch geol. Gesellsch. Diagnosis. Body broadly oval. Cephalon transverse. Glabella convex and subdivided by two longitudinal furrows, which are produced by the union of I lie proximal extremities of the lateral furrows. Eyes situated somewhat pos- teriorly. Facial sutures beginning on the posterior margin, near the genal angles, passing forward from the eyes in sub-parallel lines to the anterior mar- gin. Hi/postoma sub-quadrate, with a deep reentrant curve on the posterior margin. Centrum gently convex. Thorax composed of eleven segments. Pleurae sulcate and produced into acute terminations. Pygidium sub-triangular, gently convex. Axis very short, with but two or three annulations. Pleurae broad, sulcate. Margins lobate. '»* Sub-genus TE RAT ASP IS, Hall. 1863. 1862. Lichas, Hall. Fifteenth Rept. N. V. State Cab. Nat. Hist. 1863. Terataspis, Hall. Sixteenth Rept. N. Y. State Cab. Nat. Hist, i 371 .!< idaspis i Terataspis), Hall. Illustrations of Devonian Fossils. Diagnosis. Frontal lobe of the glabella ellipsoidal, longitudinally and transversely bisymmetrical, strongly and equally con- stricted on all sides. First and second lateral lobes coalesced and strongly spinose at their summit; third lateral lobe obsolescent or extinct. Glabellar area be- tween the anterior lobe and occipital ring much depressed. Occipital ring broad, bearing strong spines or baculate tubercles. Pygidium with one annulation upon the axis, two or three upon the pleurae, and bearing eight long, recurved, simple or compound marginal spines. SYNOPSIS OF GENERA. XXXIX Sub-genus CONOLICHAS, Dames. 1877. lSr>9. Lichas, Hall. Pal. N. V., vol. iii. 18(51. Lichas, Hall. Descr. New Species Fossils. L862. Lichas, Hall. Fifteenth Rept. N. V. stair Cab. Nat. Hist. 1869. Lichas?, Kakstens. Beitr. zur Landesk. herzog. Schleswig und li"l ti 1874. Lichas, Stewhardt. In preus. Gesch. get. Trilob. L876. Acidaspis (Terataspis), Hall. Illustrations of Devonian l'"ns.sils. I >■ 7 7 . Conolichas, Dames. Zeitsch. der deulsch. gjeol. Gesellsch. 1885. Conolichas, Schmidt. Revision Ostbalt, Silur. Trilob. 18S5. Conolichas, Zittel. .Handb d. palaeontologie. Diagnosis. Glabella with only anterior and posterior lateral furrows. Lateral lobes well defined. Frontal lobe, and sometimes the lateral lobes, conically elevated, and often inclined backward. Sub-genus HOPLOLICHAS, Dames. 1877. 1S42. AsapJius, Conrad. Jour. Acad. Nat. Sci. Phila. 1846. Lichas, Beyrich. Untersuchungen iib. Trilob. 185S. Lichas, Dethlbff and Boll. Trilobiten Mecklenburgs. 1S59. Lichas, Nieszkowski. Monogr. Trilob. Ostseeprov. 1867. Metopias, Quenstedt. Petrefaktenkunde. 1869. Lichas, Kakstens. Beitr. zur Landesk. herzog. Schleswig and Holstein. 1S74. Lichas, Steinhardt. In preus. Geschieb. get'. Trilob. 1877. Hoplolichas, Dames. Zeits?uh. der deutsch. geol. Gesell. 1.885. Hoplolichas, Schmidt. Revision O.stbalt. Silur. Trilob. 1885. Hoplolichas, Zittel. Handb. d. Palseontologie. Diagnosis. The frontal lobe of the glabella longitudinally arched, evenly convex, tubercled, spiniferous or with a single strong baculate pro- cess. Lateral furrows as in Conolichas. Occipital ring bearing a simple or compound spine. xl SYNOPSIS OF GENERA. Sub-genus ARGES, Goldfuss. 1839. vol. xix. 1837. Calymene, Grben. Am. Jour. Science. [g3g .1 N \ii. Acad. Caes. Leop. Car. [843 J ,, . i,, i ■ . ■ . . Neues Jarhb. fttr Min. Lichas, Barrandb. Notice prelim, sur le Syst. sil. Boheme. 184P. A rges, Bey rich. Untersuchungen lib. Trilob. [S47. Chrydoi < ' >pyge, part im, Corda. Prodrom Monog. bohm. Trilub. 1852. Arges, Hall. Pal. N. Y., vol. ii. 1852. Lichas, B Syst. Sil. Boheme, vol. i. 1851 Lichas, Nibszkowski. Monog. Trilob. Ostseeprov. IS58. Lichas, Hoffmann. Trilobit. Russlands. 1878. Lichas, Angblin, Palseontologia Scandinavica. 1885. Arges, Schmidt. Revision Ostbalt. Silur. Trilob. Diagnosis. Middle lobe of the glabella sub-rectangular, longitudinally arched, often spiniferous. Second lateral lobes larger than the first ; third lateral lobes inconspicuous or obsolete. Palpebral furrows indistinct. Sub-gentjs C E R A T 0 L I C H A S , n. sub-gen. Diagnosis. Frontal lobe ellipsoidal and strongly convex, faintly constricted on the abrupt and almost vertical posterior slope. The elevated posterior edge of this lobe bears two or four long recurved spines. The lateral lobes are very depressed and obsolescent, the first and second pairs coalesced, and the third pair either obsolete or represented by faint tubercles in the occipital furrow. Just within eacb palpebral lobe is a slender spine, and the occipital ring bears a long central recurved double spine. ' atolichas differs from Conolichas, Dames, in the depressed and obsolete lateral lobes: from Terataspis, Hall, in the sub-quadrate, slightly constricted frontal lobe, ami from Arges, Goldfuss, in having the frontal lobe shorter, more ele- vated, and abruptly sloping toward the posterior extremity. SYNOPSIS OF GENERA. xli Sub-genus D I C R A NOG M U S , Cord a. 1847 1846. LicTias (partim), Barrandb. Notice prelim, sur le Syst. sil. Boheme. 1 s-47. Dicratwgmus, Corda. Prodrom M lt. bohm. Tr is">2. Lichas (partim), Barrandk. Syst. Sil. Boheme, vol. i. 1S7S. Lichas (partim), Angelin. Palreontologia Scandinavica. Diagnosis. Dorsal furrows of the glabella parallel, becoming obsolete toward the anterior margin. Second lateral furrows transverse ; second lateral lobes smaller than the first ; third lateral lobes inconspicuous or obsolete Palpebral furrows not conspicuous. Family, Pkoktidk. Genus PROETUS, Steininger. 1831. 1S26. Calymene, Dai.man. Deber PaUeaden. 1829. Calymene, Holl. Handb. der Peti-efakten. 1831. Proetus, Steininger. Mem. Soc. g6oI. de Finance. 1832. Calymene, Goldfuss. Dechen's Handb. 'I. Geognosie. 1832. Calymene. Green. Mon. Trilob. North America. is:!7. Calymene, Hisinger. Lethffia Suecica. 1837. Calymene, Quenstedt. Wiegniann Archiv. 183S. Calymene, Green. Amer. Jour. Science. L839. Calymene, Conrad. Second Ann. Rept. Pal. N. V. 1839. Asaphus, Mdrchison, Silurian System. 1839. Asaph ns. Emmrich. De Trilob. Dissert. L840. Calymene, Milne-Edwards. Hist. Nat. Crust, fossiles. 1842. Calymene, D'Archiai ami De Verneuil. Trans. Geol. Soc. L leu. 1842. Asaphus, Conrad. Jour. Acad. Nat. Sci. 1843. Qerastos, Goldfuss. Leonhardt and Bronn's Neues Jahrb. fur Min, 1843. Proetus, 2Eonia, Bl-rmeister. Organiz. d. Trilob. 1S43. Calymene, Hall. Kept. Fourth Dist. N. Y. 1844. Cferastos, C. F. Rojmer. Rhein. Uebergangsgeb. 1S4.">. Cferastos, Emmrich. Neues Jahrb. fur Min. 1845. Proetus, Loven. Ofversigt. af. Kongl. Vetensk Akad. Forhandl. 1846. Proetus, Barraxde. Notice pr'eTim. sur Syst. Sil. Boheme. 1846. Proetus, Beyrich. Untersucbungen iib. Trilob. 1546. Forbesia, McCoy. Synopsis Sil. Foss. Ireland. 1846. Proetus, Rouaolt. Bull. Soc. ge"ol. de France. 1547. Proetus, Xiphogonium, Corda. Prodrom Mon. bohm r 184S. Proetus, Phillips ami Salter. Mem. Geol. Surv. Unit. -a Kingdi m. 1850. Trigonaspis, Cylindraspis, the Brothers Sandbergbr. Verst. 'I. Rhein. Schl Sysl 1S50. Proetus, F. A. R. Proetus, Giebel. Silur. Faun. Unterharz. 1859 /' lus, II ml. Pal. N V.. vol. iii. 18(50 /' lus, Hall. Thirteenth Rept. N. Y. State Cab. Nat. Hist. I860. /'." lus, Bn lings. Canadian Naturalist and Geologist. 1S61. Proftus, Hall. Descrip. New Species IA.ssils. Rept. N. Y. State Cab. Nat. Hist. 1862. Proetus, Hall. Fifteenth Rept. N. Y. state Cab. Nat. Hist. 1863 P }, Shumard. Trans St. Louis Acad. S.i. 1863 Proitus, Richter. Zeitschr. der deutscher. geol. Gesellschaft. I s>; i. Proetus, Richter. Zeitschr. der deutscher. geol. Gesellschaft. IS65. Proetus, Meek and Worthen. Proc. Acad. Nat. Science. 1865 Proetus, Richter. Zeitschr. der deutsch. geol. Gesellschaft. is.;- Proetus, Meek and Worthen. Geol. Surv. Illinois, vol. iii. IS6S. Gerastos, Dewalque. Prodrom. d'une Descr. g£61. de Belgique. 1869. Proetus, Linnarsson. Vestergotl. eamb. och silnr. Aflag. L870 Proetus, Tietze. Devon. Schicht. Gbersdorf. 1871. Proetus, Meek. Proc. Acad. Nat. Science. |s7_\ Proetiis, Kayser. Zeitschr. der deutsch. geol. Gesellschaft. 1872. Proetus, Meek. Amer. Jour. Science. |s7_\ Proetus, Barrande. Syst. Sil. Boheme. vol. i, Suppl. 1873. Pi-oetus, Meek. Geol. Surv. Ohio Palseontology, vol. i. |sTl Proetus, Billings Palseoz. Foss. Canada, vol. ii. 1875. Proetus, II ill and Whitfield. Geol. Surv. Ohio Palaeontology, vol. ii. 1876. Proetiis, C. P. Rcemer. Lethiea palseozoica. . Hail. Illustrations of Devonian Fossils. IsTT. Proetus, Hall ami Whitfield. IT. S. Geol. Surv. Expl. Fortieth Parallel. Is77. Proetus, Meek. [J. S. Geol. Surv. Expl. Fortieth Parallel. 1878. Proetus, Forbesia, Cehntix, Anuelin. Pahrontologia Scaudiimvira. 1879. Proetus, Novak. Studien an Hypostomen, i. 1879. Proetus, Barris. Proc. Davenporl Acad. Science. 1880. Iiii-Ih iiilln. Kayser. Zeitsch. der deutsch. geol. Gesellschaft. lss| /•,., ,'i,,s, Williams. Amer. Jour. Science. L881. /'.' tus, Wetherby. .lour. Cincinnati Soc. Nat. Hist. 1883 Proetus, W iward. Geological Magazine. issj Proetus, Walcott. Palaontol. Eureka Dist. |ss( Proetus, Novak. Studien an Hypostomen, ii. 1885. /'" tus, Iji '/,,,,, tin, Clarke. Geol. Succession in Ontario Co. ss.v /', U , CEhlert. Bull, de la Soc. d'Etudes Scientif. d'Angei*. L885. Pro tus, .Mm rer. Kalke von Waldgirmes. 1885. /'/- tus, Zittel. Handb. d. Palseontoiogie. Is-"''- /',. lus, Maureh Fauna d. rechterhein. Unterdev. lSs7 /' Stainer. Ann. de la. Soc. ge*ol. de Bretagne. I8S7 Pri tus, Phillipsia (partim), Herrick. Bulletin Denison University. 18S7. Prt lus, Pobrstb. Bulletin Denison University. Iss7. it,,/,,,,, i, Tschernyschbw. Mem. Comite ge'ol., vol. iii. 1887. I'ii, ins, CEhlert. Annales d. Sociote Geologique, vol. xix. 1887. Proetus, \ i id] Ann. N. V. Acad. Science. 1888. Proetus, i a, Fbkch. Zeitschr. der ileutsch. geol. Gesellschaft. SYNOPSIS OF GENERA. xliii Diagnosis. Body generally small, elongate- ovate in outline. Cephahm semicircular, margin usually conspicuous and elevated ; genal angles rounded or produced into spines. Glabella tapering anteriorly, scarcely reaching the frontal margin ; lateral furrows conspicuous, faint or obsolete on the dorsal surface, distinct upon the internal sur- face. Eyes large, semilunate ; lenses small, homoeorneal. Facial sutures lie- ginning on the posterior margin, just within the genal angles, and running from the eyes in nearly straight lines to the frontal margin, terminating on the edge of the doublure. Hypostoma elongate-rectangular, margins incurved and cen- trum very convex. Thorax longer than the cephalon, composed of from eight to ten segments, which are sulcate upon the pleurae, sharply angled at the fulcrum, and rounded at their extremities. Pijgidium sub-semicircular. Axis arched and bearing from four to thirteen annulations; pleurae annulated ; mar- ginal area broad and entire. The genus Prottus possesses a greater specific representation in the Devo- nian formations of North America than any other group of TrilobUes, and appears to have attained its culmination of development both in species and individuals in the waters which deposited the limestones of the Upper Helder- berg group. But notwithstanding the abundance of specimens in these rocks, our knowledge of many of the species is imjjerfect on account of their usually fragmentary condition, and more complete material may eventually require the union of some of the forms described from detached parts of the animals, and which are now of necessity regarded as distinct species. In the higher Devonian formations the species are fewer, but the specimens are usually more complete and more satisfactory for purposes of description. The material which has been at hand for the study of the twenty-six Devo- nian species here described is fairly representative, and in some instances com- paratively abundant. All our observations point distinctly to the fact that the genus Proitus includes a well-defined group of Trilobites, subject to but little variability in essential characters, and that the numerous subdivsions of the xliv SYNOPSIS OF GENERA. lus erected by various authors have not been founded on the broadest conception of the value of slight variations. \\ ith the single exception (P. longicaudus),n\\ the American Devonian species possess ten thoracic segments; this one has but nine, and were this feature to he accorded generic significance, the species would fall under the subdivision Xiphogonium, Corda (Prodrom Monogr. bohm. Trilob., 1847). Ten however is the normal number of segments for the genus, and the possession of but nine I /'. Kulptus, Barrande), or even of eight (P. Barrandii, P. A. Roemer), is perhaps to I"' regarded as an embryological character retained in maturity. It has been customary to constitute subdivisions of this genus, and even distinct genera, upon the variations in the form of the glabella, and in the apparent number and length of the transverse glabellar furrows. Evidently the fact has fre- quently been overlooked that a glabella which evinces no trace of these fur- rows upon the external surface, will, under favorable weathering or upon a cast of the internal surface, show the normal number of four pairs and the poste- rior accessory pair of furrows. In occasional instances, where the ornamenta- tion of the crust of the glabella has been preserved without defect, traces of all these furrows may be observed, but this is not true of species in which the glabella is normally smooth. The vertical compression of the crust, causing it to give way along the furrows, often develops them, or the slight detach- ment of the crust from its matrix makes them apparent by translucence. Thus the species Prottus folliceps, P. crassimarginatus, P. Haldemani, P. Rowi, in normal preservation, have a smooth, unfurrowed dorsal surface, but either in casts of the internal surface, or in cases of compression, show all the char- eristic glabellar furrows. In the former condition of preservation P. fol- liceps, I', crassimarginatus, P. clarus, P. Haldemani, P. Rowi and P. macrocephalus would follow the type of Gerastos, Goldfuss; P. canaliculatus and P . longicaudus would belong to the genus Mania, Burmeister. In other states of preservation P. folliceps, P. Haldemani, P. Rowi and P. macrocephalus would fall under the recentl) established genus Dechenella, Kayser. Therefore, and for the addi- tional reason tli.it even upon the internal surface of the glabella the furrows are subject to great variation in development (in P. crassimarginatus and SYNOPSIS OF GEN Ell A. xlv P. ovifrons being almost extinct), it becomes manifest!}' impossible to ascribe even a sab-generic value to such variations. Tbe sub-genus Phaeton was proposed by M. Barrande, in 1846, for forms of Proetus in which the pygidium bears a marginal fimbria caused by the ex- tension of the annulations. Forbesiu, McCoy, 184G (Proetus concinnus, Dalman, type), is a Proetus in which but two pairs of lateral furrows have I n observed. Celmus, Angelin, 1878 (C. granulatus, Aug.. type1), is founded upon an ex- ample in which there are twelve thoracic segments and bul two pairs of lateral furrows. These last two genera are as yet imperfectly known, and may prove to include species showing a structure intermediate between thai of the true Proetus and of Cyphaspis. Genus PH AETHON I D ES, Angelin. L878. 1835. Asaphus (partim). Mi si hison. Silurian System. 1S4T). Proetus (partim), Loves. Ofversigt. af. Kong-1. Vetensk. Akad Eorhandl. 1S4B. Phaeton, Barrande (*). Notice pie"liminaire sur les Syst. Sil. Bohi 1M7. Prionopdtis, Corda (?). Prodrom Monog. bohm. Trilob. 1852. Proetus (Phaeton), Barrande I !). Sj 3t. Sil. Boheme. vol. i. L863. /'■■ rtiin), Billikgs. Dev. and Silur. Foss. Square Lake, Me. \-::. Proetus (Pha ton), Mkbk. 1 . s. Geol. Suiv. Expl, Fortieth Parallel. 1S7S. Phaethonides, Angelin. Pal: Sc mdinavica. 1SS5. Phaeton, CEhlert. Bull, de la Soc. d'Etudes Scientif. d'Ang Diagnosis. Cephalon as in Cyphaspis, the fron- tal area, however, being more deeply concave, and the lateral glabellar furrows stronger and generally duplicate. Thorax composed of not less than seven narrow segments, and probably more. Axis wide. Pygidium Proetoid, relatively large, bearing from eight to twelve annulations upon the axis, and eight or nine upon the pleura?. These annulations extend to the margin, and are conspicuously duplicate their entire length. Surface tubercled or smooth. xlvi SYNOPSIS OF GENERA. The term Phaeton was used by M. Barrande in 1846 (Notice preliminaire sur le Systeme Silurien el les Trilobites de Boheme, p. 62), to include a certain series of Trilobites possessing Proetoid characters, but differing from the normal ProUus in having the annulations of the pygidium produced into a marginal fimbria. This tenn was at first given generic value, hut subsequently reduced by its author S\ st Sil. de Boheme, vol. i, p. 433, 1852), to the position of a sub- genus. The name Phaeton was long previously used by Linnaeus for a genus of birds, and in 1817, Corda (Prodromeiner Monographic der Bohmischen Trilobi- ten) made use of the tenn Prionopeltis for the same group. In 1878, Angelin, in the posthumous edition of the Paheontologia scandinavica (part i, p. 21), referred to the group under the term Pha/fhonides, ascribing the credit of the name to Barrande, giving it generic value and re-defining the genus in the following words : " Corpus latiusculum, sub-ovate, distincte longitudinaliter trilobum, testa laevissima, aciculata tectum. " Ca/iut serailunare, undique marginatum canaliculoque lato, intramarginali proeditum. Anguli capitis exteriores cornigeri. Frons ovata marginem api- calein baud attingens, utrinque lobo 1 distincto basali, lineisque 2 obsoletis abbreviatis impressis. " On//i sat magni, semi-circulares, approxiinati, sub-basales. Sutura facialis utrinque ab oculis extrorsum flexa, postice ad latera capitis anticeque ad margi- nem apicalem ducta. " Thorax e segmentis 10, sulco pleurico instructis ; rachi pleuris angustiore. '■'■Abdomen majusculum, semi-circulare, immarginatum, margine integerrimo aut dentato; rachis angusta, sub-cylindracea, aute scuti apicein evanescens; latera scuti sub-plana, costis dichotomis." As thus amended the group is made to include not only species with fimbri- ated pygidia, but also such as have the pygidial margin entire; cephala with a short, ovoid glabella, having distinct basal lobes and two pairs of faint, obso- lescent lateral furrows in front of the lobes. The type species under Angelin's diagnosis is Asaphus (Proitus) Stokesi, Murchison, in which the pygidium has an entire margin, and the cepbalon irs features which are more closely similar to those of the genus Cyphaspis SYNOPSIS OF GENERA. xlvii than of Proetus, namely: the glabella is short and ovoid, with large, sub-pyri- lbrni basal lobes distinctly separated from the body of the glabella, frontal area broad and conspicuous. In the type species of Phaeton, however (Proetus Archiaci and P. striatus, Barrande), the glabella is sub-quadrate or broadly conate, the basal lobes not separated from the glabella by the third lateral furrows, while the two pairs of anterior furrows arc clearly visible. Angelin's genus Phaithonides includes a well-defined group of trilobites allied in certain features of the cephalon to Cyphaspis, and in certain features of the pygidium to Proetus, but it appears very doubtful if this term can be used with propriety to cover the species recognized by Barrande under the name Phut ton. Phaethonides is represented in the American formations by four species, two from the Lower Helderberg and two from the Devonian, and both cephalon and pygidium of all these are known. A doubtful species is known from the Devonian rocks of Nevada, which seems to be more closely allied to the Phaiton of Barrande than to the Phaithonides of Angelin. Shall it eventually prove necessary to separate the species originally included under Phaiton as generically distincl from Phaethonides, recognition should be accorded to the term Prionopeltis, Corda, 1847, which name was proposed for the same variations included under the term Phaiton, Barrande. Genus CYPHASPIS, Burmeister. 1843. 1843. Cyphaspis, Bi rmeister. Organ, der Trilobiten. 1543. Calymene, F. A. Rcemer. Verstein. des Harzgeb. 1843. Gerastos, Goldfuss. Leonhnrdt and Bronn's Neues Jahrb. fiir Min. 1544. Phacops, C. F. Rcemer. Verstein. it. Rhein. Uebergangsgeb. 1S4T). Proetus, Lovex. Ofversigt. :if. Kcmgl. Vetensk. Akad. Forhandl. 1846. Cyphaspis, Geixitz. Grundr. der Verstein. 1546. Cyphaspis, Barrande. Notice prelim, sur. Syst. Silur. 1547. Cyphaspis, Conoparia, Gfoniopleura, Corda. Prodrom Monogr, bohm. Trilob 1850. Cyphaspis, the Brothers Sandbbrger. Verstein. d. Rhein. Schichtensyst. 1852. Cyphaspis, Barrande. Syst. Sil. Boheme, vol. i. 1852. Cyphaspis. F. A. Rcemer. Beitr. ii zur Barzgeh 1855. Cyphaspis, Sht.mard. Geol. Surv. Missouri. 1855. Cyphaspis, F. A. Rcemer. Beitr. iii zur Hai'zgeb. 1S5S. Cyphaspis, Giebel. Silur. Fauna (Jnterharz. 1862. Cyphaspis, Hellmaxx. Die Petrefackten Thiiringens. 1863. Cyphaspis, Hall. Trans. Albany Institute. 1869. Cyphaspis, Haidexhaix. Zeitschr. der deutsch. geol. Gesellsch. 1872. Cyphaspis, Barrande. Syst. Sil. Boheme. vol. i, suppl. XlVlll SYNOPSIS OF GENERA. 1874 Cyphaspis, Steiuhardt. I>i'' l>is jetzl in preuss. Geschieb. get. Trilob. LS75. CypJiaspi . Hi rer. Neues Jahrb. fiir Min. 1876. Cyphaspis, C. F. Rckmek. Lethaea palseozoica. 1876. Phillips '). Hall. Illustrations of Devonian Fossils. ISTn. Cyphaspis, Kayser Faun. aelt. Devon. Ablag. des. Harzes. ls;s {, , a, Asoelin. Palseontologia Scandinavica. . II w.i.. Twenty-eighth Rept. N. V. State Mus. Nat. History. 18SI. Cyphaspis, Hall. Eleventh Ann. Rept. Geol. Surv. Indiana. 1880. Cyphaspis, Whim Second Ann. Rept. Geol. Survey Indiana. 1884. Cyphaspis, Ci ihke. Neues Jahrb. fur Min. 18S4. PhUlipsia f, Cyphaspis, Walcott. Palseontol. Eureka District. 1885. Cyphaspis, Clarke. Geol. Succession in Ontario Co. l--:., Cyphaspis, Maursk. Fauna der Kalke von Waldgirmes. 1S85. Cyphaspis, Zittel. Handbuch d. PaUeontologie. IS86 Cyphaspis, Maurer. Fauna d. rechtsrh. Unterdevon. ISS6. Cyphaspis, Barrois. Ann. de la Soc. g-6ol. du Nord. Diagnosis. Cephalon semicircular; genal angles produced into long spines. Glabella strongly arched, short and narrow, with two small pyriform basal lobes, bounded on all sides by deeply impressed furrows. Anterior lateral furrows obsolete. Cheeks broad, gran- ulose; eves small, semilunate. Facial sutures beginning near the genal angles, and in front of the eyes diverging to the frontal margin. Thorax composed of from seventeen segments, which are rounded at their extremities. Pygidium circular, bearing from two to eight annulations upon the axis. ten to semi- XIPHOSURA. Family, Limulih.e. Genus P ROTOLI M IT L U S, Packard. 1886. 1885. Prestwichia, II. S.Williams. Amer. Jour. Science. [886. Protolimwliis, Packard. Mem. Nat. A.cad Sciei s. Diagnosis. Cephalothorax relatively large, sub-semicircular, genal angles produced. Cephalic appendages small; terminal segments of the posterior members foliaceous. Abdomen composed of six(?) segments, including the large caudal spine. synopsis of gi:ni:ha. s 1 i x Neolimulus falcatus, Woodward. Tliis genus is represented by a single species which demonstrates the early ap- pearance of the true limuloid Crustacea. It is probable that its nearest known ally is the Neolimulus falcatus, Woodward, from the Upper Silurian of Lanarkshire. The latter fossil is regarded by Packard (Mem. Nat. Acad. Sci., p. 151, 1886), as not referable to the Xiphosura, and, together with the genera Hemiaspis, Bunodes, Pseudoniscus and others are made to constitute a distinct group {suborder, Packard), Synzipho- sura. This separation is made principally on the ground that in all these forms the abdomi- nal segments are free and not coalesced as in Limulus. It may be questioned whether the non-anchylosis of the segments has been satisfactorily demonstrated in Neolimulus, or if so, whether a division of so high value as a sub-order is wisely established upon a single larval character. E U R Y PTERID A . Family, Eurypterid/e. Genus EURYPTERUS, Dekay. 1825. L825. Eurypterus, Dekay. Ann. Lyceum Nat. Hist. New York. 1831. Eidothea, Scouler. Edinburg Journ. Nat. and Geograph. Science. 1S35. Eurypterus, Hablan. Med. and Phys. Researches. 1835. Eurypterus, Harlan. Trans. Geol. Society Penna. 1835. Eurypterus, Bronn. Letliaea geognostica. 1836. Eurypterus, Hiebert. Trans. Roy. Soc. Edinburg. 1839. Eurypterus, Fischer. Bull. de. laSoc. Imp. des Naturalistes de Moscou. 1841. Eurypterus, Conrad. Ann. Rept. Pal. New York. 1843. Eurypterus, Yanuxem. Geol. N. Y.; Rept. Third Dist. 1S43. Eurypterus, Burmeistr. Organ, der Trilobiten. 1848. Eurypterus, C. F. Roemer. Palaeontographica. 1850. Eurypterus, C. F. Rcemer. Lethaea geognostica. 1S53. Eurypterus, Dana. Crust. U. S. Expl. Exped. Capt. Wilkes. 1854. Eurypterus, Eichwald. Bull, de la Soc. Imp. des Naturalistes de Moscou. 1855. EurypU rus, McCoy. British Pala>oz. Fossils. 1855. Lepidoderma, Redss. Denkschr. der Akad. Wissensch. Wien. 1856. Eurypterus, Huxley. Quart. Jour. Geol. Soc. 1 SYNOPSIS OF GENERA. 1856. Lesmahago, Mubchisojj. Quart. Journ. Geol. Soc Himantopterus, Salter. Quart. Jour. Geol. Soc. Eurypterus, Banks. Quart. Jour. Geol. Soc. L858 Ear , Saltbr. Quart. Jour. Geol. Soc. Page. Advanced Text-book of Geology. Eurypterus, Dolichopterus, Hall. Palaeontology N. V.. vol. iii. 1859. Eurypterus, Huxley and Salter. Mem. Geolog. Surv. United Kingdom. rus, Nieszkowski. Archiv. fur Naturkunde Liv, Est und Kurlands. [863 i .Salter. Quarterly Journal. Geol. Soc. 1864. Eurypterus, Woodward. British Assoc. Rept. 1864. Eurypterus, Woodward. Geological Magazine. 1868. Eurypterus (Anthraconectes), Meek and Wokthen. Amer. Jour. Sri. Mir,.. 1868. Ei Anthraconectes), Meek and Worthbn. Geol. Surv. Illinois, vol. iii. 1868. Eurypterus, W iward. Quart, -lour. Geol. Soc. [869 Pterygot . I'.aii.y. Brit. Assoc. Rept. 1870. / , W ward. British Assoc. Rept. 1871. Eurypterus, Woodward. Quart. Jour. Geol. Soc. IS7I. Eurypterus, Woodward. Trans. Woolhope Club. \^'L1. Eurypteru i, Barrande. Syst. Sil, du Centre de la Boheme. Suppl. is;-.'. Eurypterus, Wi ward. Monogr. Brit. Foss. Merostomata. 1876. Eurypterus, C. F. Rojmkr. Lethsea palsozoica. 1877. Eurypterus, Dolichopterus, C. E. Hall. Trans. Amer. Philos. Sue. |ss:>. En rypterus, Pohlman. Bull. Buffalo Soc. Nat. Sci. 18S2. Eurypterus, Whitfield. Descr. New Species Fossils from Ohio. 1884. Eurypterus, Hall. Eurypteridse Devon, and Carbonif. Format. Penna. Rept. P 3. l^--l. Eurypterus, Whiteaves. Geol. and Nat. Hist. Surv Canada. Palseoz. Fossils. Is^T. Eurypterus, Woodward. Geological Magazine. Diagnosis. Body elongate. Cephalon about one-fifth the length of the body, sub-quadrate in outline, gently convex. Eyes large, reniform, situated some- what anteriorly, and within them lie two ocular punctoe or ocelli. Oral aperture surrounded by five pairs of cephalic appendages, in front of which is a pair of minute antennules. The first three pairs of appendages or gnathopods are of approximately the same length, the joints of the fourth pair being more elon- gate and the fifth pair being developed into powerful swimming appendages, the Last two segments of which are very broad and Hat. Behind the mouth lies an oval plate i Metastoma). Abdomen upon the dorsal side composed of six segments, the first of which corresponds to the operculum of Limulus. Upon the ventral surface there are but five segments apparent, all of which are divided by a median suture, the lirst two bearing median processes extending posteriorly. The first segmenl also hears a series of symmetrically arranged median plates, which may be connected with the genital apparatus. Post- abdomen composed of six tapering segments ami a long slender caudal spine. SYNOPSIS OF GENERA. Genus STYLONURUS, Pack. 1850. 1850. Stylonurus, Page. Advanced Text-1 k of Geology. 1857. Eurypterus, Salter. Edinb. New Phil. Jonrn. 1859. Stylo7iurus, Page. Advanced Text-1 k of Geology, 2d ed. 1859. Eurypterus | i>,aiim), Salter. Quart. Joura. Geol. Society. 1859. Eurypterus, Salter. In Mui-ehison's Siluria, 3d ed. 1864. Stylonurus, Woodward. British Assoc. Rept. 1867. Stylonurus. Murchison's Siluiia, 4th ed. 1881. Equisetides, Dawson. (?) Quart. Journ. Geol. Soc, vol. xxwii. 1882. Stylonurus, Martin. Trans. N. Y. Acad, of Sciei 3. 1S83. Dolirlioct -phalli. Claypolb. Proc. Auier Philos. Soc. 1883. Stylonurus, Hall. Thirty-sixth Rept. N V. State .Mas. Nat. Hist. Diagnosis. Body in general propor- tions similar to Eurypterus. Cephalon sub-quadrate or sub-pentagonal in outline. Eyes large, circular and approximate, sometimes surrounded by conspicuous orbital ridges. Ocelli situated at the posterior extremity of a median ridge, passing between the eyes. Surface coarsely squamose. Cephalic appendages in five (?) pairs, the last of which are produced nearly to the extremity of the telson. Seg- ments of the Abdomen as far as known, similar to those in general features of Eurypterus. Those of the post- abdomen each bear a pair of lateral, detachable processes or epimera. Cau- dal spine long and slender or sub- clavate. Restoration ol Stylonurus Logani, ai ng to Woodward. lii SYNOPSIS OF GENERA. ORDE R, PHY LLOCAR] DA. Family. ( 'kratiocariiu;. ( , encs C 1-: R A T I 0 C A K 1 S , McCoy. 1849. LS39 0» Agassiz. Murchison's Silurian System. in), Phillips. Mem. Geol. Surv. United Kingdom. Pterygotus, Ceratiocaris, McCoy. Ann and Mag. Nat. Hist. [851. I McCoy. Brit. Palieoz. Foss. 1851. Pterygotus (Leptoclieles), Bronn. Lethsea geognostica. LS52. Hai i .. Pal. N. Y., vol. ii. i eratiocaris, Bronn. Lethsea geognostica. IS53. Dithyrocaris, Geinitz. Verstein. Grauwacken. Sachsen. I-:,:: LeptocMes, McCoy. Quart, .lour. Geol. S 1853 Ceratiocaris (1 Barrande. Neues Jahrb. fur Min 1853. Dithyrocaris?, Sharpe. Quart. Joui-n. Geol. Soc. LS54 Ceratiocaris, Leptocheles, Mdrchison. Siluria. 1856. Ceratiocaris, Salter. Quart. Journ. Geol. Soc. / . Hall. Pal. N. Y., vol. iii. 1859. Ceratiocaris, Salter. In Murchison's Siluria. 1860. Ceratiocaris, Salter. Ann. and Mag. Nat. Hist. I860. Ceratiocaris, Angblin. Palaeontologia Scandinavica, suppl. 186."i. Ceratiocaris, Woodward and Salter. Charl Foss. Crustacea. Ceratiocaris, Woodward. Geol. Magazine. Ceratiocaris, Woodward. Geol. Magazine. [866. Ceratiocaris, Salter. Mem. Geol. Surv. United Kingdom. 18ii7. Ceratiocaris, Salter. In Murchison's Siluria. 1868. Ceratiocaris?, Meek and Worthen. Am. Jour. Sci. and Pal. 111., vol. iii. 1>7I ' ratiocaris. Woodward. Geol. Magazine. 1872. Ceratiocaris, Woodward. Geol. Magazine. 1872. CI atioeai-is, Barrande. Syst. Sil. Boheme, vol. i, suppl. 1872. Ceratioi caris), Meek. Proc. Acad. Nat. Sci. Phila. 1873. Ceratiocaris, Etheridge. Mem. Geol. Surv. Scotland. IS74 C&utiocaris, Etheridge. Ann. and Mag. Nat. Hist. is7;,. Ceratiocaris [Cdipocaris), Meek. Geol. Surv. Ohio Palaeontology, vol. ii. 1876. ■ ■ ris, C. I-'. Rcembr Lethsea palseozoica. 187S. Ceratiocaris, Young. Proc. Roy. Phys. Soc. Edinb. [881. CI , POHLMAN. Bu Bu Sue. Nat. Sri. . Turn. Trans. Roy. Soc. Edinb. 1853. ( . Pai i. mm.. Monog. North Amer. Phyllop. Crust. ins:; Ceratiocaris, Etheridge, Wood\i ird and Jones. Rept. Committee Fossil Phyllop. 1854. ''- ai . I'.i: ' iiki:. Ceratiocaridae Chemung and Waveriy groups, Geol. Surv.Penna. Repl.P 3. ./.mi bl. Handb. -1. Pala tologie l^sr,. Ceratwa '■ lk. Sitzungsb. bohm. Gesellsch. d. Wissensch. 1885. Cera Clarke. Devon. Faunas Ontario Co. l^s.-,. Ceratiocaris, Clarke Geol. Succession in Ontario Co. [885. Ceratiocaris, ■ I Woodward. Geol. Magazine. I88i , Pom •■! \n. Bull. Buffalo Soc. Nat. Sri. 1887. ' Etheridge, Woodward and Jokes. Fifth Rept. Committee Fossil Phyllop. Palsoz. cks. [888. Ceratiocaris, Jones and Wo idward. Geological Magazine. March and April. SYNOPSIS Or GENERA. liii Diagnosis. Carapace bivalved, prob- ably with membranous attachment, no distinct hinge-joint observable; valves sub-ovate, semi-ovate, sub-quadrate or trapezoidal; contracted in front, with the end sharp or rounded above the median line of the valve; more or less truncate. Rostrum a single lanceolate piece, the surface of which is chevron- marked. Antennas (?) obscure. Dentate mandibles often apparent. Abdomen many-jointed, with fourteen or more segments, of which from four to seven extend beyond the carapace. Some or all of these segments bore small lamelli- form branchial appendages. Post-abdomen consisting of a long caudal plate which supports three caudal spines, namely : (1) a strong, tapering telson, thick at the proximal end, with its trifid articulating surface resembling that in the telson of Limulus, acute at the distal extremity and with the lateral margins ornamented with spinules or setae ; and (2) two shorter, simpler, lateral append- ages. The entire dorsal surface has alineate ornament, and the ventral margin of the carapace a thin raised rim. (Jones and Woodward, Geol. Mag., Decade iii, vol. ii, p. 385. 1885.) The species from the North American Devonian which arc referred to this genus, are represented only by very incomplete specimens, which leave much to be desired for an accurate determination of their generic relations. The genus reached its culmination both in specific and individual development in the Upper Silurian and probably became extinct in this country with the close of the Devonian age. Genus ECH1NOCARIS, Whitfield. 1880. 1863. Cemtiocaris, Hall. Sixteenth Rept. N. Y State Cab. Nut. Hist. 1876. Cemtiocaris (Aristozoe), Hall. Illustrations of Devonian Fossils. 1880. Echinocaris, Whitfield. Aiimt. Joui-n. Science. lS.si. Equisetides, Dawson ('). Quart. Journ. Geol. Soc, vol. xxxvii. n;s-j. Echinocaris, Packard. American Naturalist. I8S3. Echinocaris, Packard. Monog. N. Amer Phyllop. Crustac P 3. 1884. Echinocaris, Beecher. Ceratiocaridae Chemung1 and Waverly groups, Geol. Surv. Penna. Kept. 1884. Echinocaris, Jones and Woodward Geolog. Mag. 18S5. Echinocaris, Etheridge, Woodw LRDand Jones. Third Rept. on Fossil Phyllopoda. 18S5. Echinocaris, Zittel Handb. d. Pateontologie. 1885. Echinocaris, Novak. Sitzungsber. d. bohm. Gesellsch d. Wissensch. 18S5. Echinocaris, Clarke. Devon. Faunas Ontario Co. 1886. Echinocaris, Clarke. Geol. Succession in Ontario Co. liv SYNOPSIS OF GENERA. Diagnosis. Carapace hi valvular, each valve obliquely sub-ovate in outline: hinge-line straight and shorter than the greatesi length of the shield. Anterior ex- tremities slightly gaping, posterior extremities some- what produced, incurved or truncate. Rostrum absent or not observed. The cephalic and anterior portion of the thoracic area marked by various regularly and sym- metrically arranged nodes, two of which bear the optic spots. Nuchal furrow more or less distinct. The tho- racic portion of each valve bears one or two longitudi- nal, somewhat curving lateral ridges or carina?. Abdo- men naked, composed, so far as known, of six somites, which are furnished with short spinules or prickles on their dorsal surface. Caudal plate short and produced into a stout telson. Lateral spines or cercopods nar- row and longer than the telson. There are now known seven species referable to this genus in which the carapace has been observed, and while these are well-defined by differences in outline and the development of the nodes and ridges upon the surface, it appears that the nodes are constant in number and disposition in all the species. Of these nodes the cephalic region bears two, the anterior of which is large, irregularly defined and sometimes strongly tubercled upon its surface (E. punctata, E. socialis), the posterior small and situated close upon the hinge-line; the thoracic region also bears two, one at the hinge-line just behind the nuchal furrow, obliquely and anteriorly produced ; the second originating near the ventral extremity of the first, transversely and posteriorly elongated and sometimes continuous with the lateral carina. (E. subhevis, E. pustulosa.) It is important to notice that certain species of the genus Aristozoi-, Barrande, exhibit an arrangement of the cephalothoracic nodes very similar to that in Echinocaris (A. memoranda, A. regina, A. bisulcata), while other species included under that genus are widely dissimilar in this respect. None of the carapaces SYNOPSIS OF GENERA. lv in Aristozoe bear lateral carinas. It has recently been shown b\ Novak (Sitz- ungsber. d. Kl. bohm. Gesellsch. d. Wissensch. Jahrg. L885,) thai the species Badropus longipes, Barrande, is probably the posterior abdominal somite of Aristozoe regina, and that the Ceratiocaris debilis, Barrande, may prove to be the telson spine of the same species. This spine is longitudinally ridged and hears a row of short prickles along each lateral margin. The genus Ptijchocaris, Novak, 1885, from the same beds as Aristozo'e, presents an intermediate group of forms in which the lateral carina is present, but in the arrangement of the anterior nodes it differs from both Echinocaris and Aristozoe. The points of similarity in Aristozoe and Ptychocaris with Echinocaris are of interest as the former genera antedate Echinocaris in palaeozoic faunas, being characteristic of the Etage F, or Hercynian Fauna of Kayser and Novak, while the genus Echinocaris is limited to middle and upper Devonian formations, and as yel known is exclusively American in its distribution. Genus ELYMOCARIS, Beechee. 1884. iss4. Elymocaris, Beecher. Ceratiocaridse Chemung and Waverlj groups, Geol. Surv. Penna.Rept. l':i. 18S5. Elyiaoearis, Etheridge, Woodward and Jones. Third Kept. Committee Foss. Phyllop. 1885. Elymocaris. Zittel. Handb. d. Palaeontologie. Diagnosis. Carapace bivalvular, hinge-line straight and extend- ing nearly the entire length of the valves. Outline elongate-sub- quadrangular or sub-ovate. Surface gently and evenly convex. Cephalic region smooth or marked by two low broad nodes ; optic node usually distinct. Rostrum absent or not observed. Abdo- men composed of two naked segments. Post-abdomen with a very short caudal plate to which are articulated a broad, convex and rapidly tapering telson and two short lateral spines which are crenulated along their inner margins for the attachment of the set*. Genus T R 0 P I D 0 C A R I S, Beecher. 1884. 1884. Tropidoearis, Beecher. Ceratiocaridai Chemung and Waverl; • l.Surv.Penna.Rept,P3. 1884. Tropidoearis, Etheridge, W ward and Jones. Third Rept. Committee Foss. Phyllop. 1885. Tropidoearis. Novak. Sitzungsber. bohm. Gesellsch. d. Wissi nsch. 1885. Tropidoearis, Zittel. Handb. d. Palseontologie. lvi SYNOPSIS OF GENERA. Di ignosis. Carapace bivalvular, sub-quadrate or sub-ovate in outline, posterior margin transverse or incurved. Hinge-line straight, nearly equaling the length of the valves. Valves slightly gaping at the anterior extremity. Rostrum narrow and elongate, ornamented with longitudinal ridges. Cephalic region characterized by low, rounded, indistinct elevations. Optic node well defined. Surface with one or more strong longitudinal carinoe. Abdomen, as far as known, composed of two segments, which are sub-cylindrical and without nodes or spin Family, Pinacarid^:. Genus MESOTHYRA, nov. gen. (See Plate xxxii.) Diagnosis. Carapace sub-quadrate in outline, composed of two valves which conic into contact at the apices of two broad, sub-triangular extensions, situated on the dorsal line opposite the eye-nodes,' forming a short and broad anterior, or rostral cleft and a long posterior cleft. Rostrum not observed. The pos- terior dorsal cleft was covered either by a single elongate plate, with each margin of which the valves were in symphysis, or, as is more probable, by a double plate, divided by a median suture. Test broadly infolded on the lower surface, thickened and produced into a conspicuous and acute posterior spine. Posterior margin incurved and produced into a short spine at the dorsal line. Surface with a single strong carina on each valve. Abdomen consisting of two somites of which the posterior is the longer. Post-abdomen with a broad caudal plate, which is produced into a relatively short telson. Lateral spines long and setaceous. This genus is established to include certain species hitherto referred, on in- sufficient grounds, to the genus Dithyrocaris, Scolder. The peculiar structure of the hinge area separates it widely from Dithyrocaris, unless the type species of that genus has been inadequately described. There is, however, so close a similarity in these forms of Mesolhyra with many of the described species of Dithyrocaris, in all respects except the feature noticed, as to give rise to a sus- SYNOPSIS OF GENERA. lvii picion that a closer examination, of specimens of the various species described under the latter genus, may afford evidence of the structural features exhibited in Mesothyra. No simple bivalved carapace unquestionably referable to the genus Dithyrocaris, is known in the American Devonian ; the species Dilhyrocaris Belli, Woodward, from the Middle Devonian of Gaspe, being too inperfectly known to allow its generic relations to be determined. To facilitate a com- parison of these two genera, the following index to the literature of the genus Dithyrocaris is given : Genus DITHYROCARIS, Scouler. 1843. 1835. Aryas, Scouler. Records of Science. 1843. Dithyrocaris, Poktlock, Geol. Rept. Londonderry. 184-1. Dithyrocaris, McCoy. Syn. Carb. Foss. Ireland. 1849. Dithyrocaris, McCoy. Ann. Mag. Nat. Hist. 1855. Dithyrocaris, McCoy. Syn. Brit. Pal. Fossils. 1S55. Dithyrocaris, F. A. Rce.mer. Beitr. iii zur Harzgeb. 18(53. Dithyrocaris, Salter. Quart. Jour. Geol. Society. Im'iI. Dithyrocaris, Ludwig. Pahvontographica, vol. xi. 1865. Dithyrocaris, Salter and Woodward. Chart of Fossil Crustacea. 1869. Dithyrocaris, Meek and Worthen. Proe. Acad. Nat. Sci. Philadelphia. 1S7U Dithyrocaris, Woodward. Rept. Brit. Association. 1871. Dithyrocaris, Woodward. Rept. Brit. Association. 1871. Dithyrocaris, Woodward. Geol. Magazine. 1873. Dilhyrocaris, Meek and Worthen. Geol. and Pal. Illinois, vol. v. 1873. Dithyrocaris, Woodward and Etheridoe. Mem. Geol. Surv. Scotland. 1873. Dithyrocaris, Woodward ami Etheridge. Geol. Magazine. 1874. Dithyrocaris, Woodward and Etheridge. Geol. Magazine. is"1-. Dithyrocaris, Kayser. JElt. Devon. Ablag. Harz. 1S78. Rachura, Scudder. Proc. Boston Soc. Nat. History. 1879. Dithyrocaris, Etheridge. Quart. Jour. Geol. Society. 1882. Dithyrocaris, Packard. Amer. Naturalist. 1883. Dithyrocaris, Packard. Monog. N. Amer. Phyllop. Crustacea. 1884. Dithyrocaris, Clarke. Neues Jahrb. fur Min. 1884. Dithyrocaris, White. Thirteenth Ann. Rept. Geol. Surv. Indiana. 1885. Dithyrocaris, Novak. Sitzungsb. bohm, Gesellsch. d. Wissenschaf't. 1887. Dithyrocaris, Etheridge, Woodward and Jones. Fifth Rept. Committee Foss. Phyllop. Diagnosis. Carapace sub-quadrate in outline, bivalvular, the valves being connected by a simple, straight hinge-line, and gaping at the anterior extremity, forming the rostral cleft. Rostrum unknown. Each valve bears a single, gently curved carina. Optic nodes generally conspicuous. Abdomen composed of ? segments of which but one is naked. Post-abdomen consisting of caudal plate and three caudal spines. hiii SYNOPSIS OF GENERA. Family, Rhinocarid^e. Genus RHINOCARIS, nov. gen. Diagnosis. Cephalothorax univalvular, later- ally appressed ; outline as in Ceraliocaris. An- terior extremity produced into a narrow, ver- tically flattened prora continuous with sub- stance of the carapace. The axial line of the carapace bears a low ridge along which it shows no inclination to separate when laterally compressed. Surface smooth or with one or more lateral carina), and ornamented by finely elevated lines, granules or tubercles. Abdomen composed of not less than four smooth sub-cylindrical somites. Post-abdomen bearing three spines, of which the telson is elongate and conical and the cercopods flattened. This genus includes a series of forms which may tentatively be regarded as Phyllocarida, but which represent a type of crustacean structure hitherto unre- alized, taxonomically intermediate between the univalve Phyllocarida, Hymenocaris and Dictyocaris, and the Macrourous Decapoda. Family, Discinocarid^e. Genus SPATHIOCARIS, Clarke. 1882. Iv^-'. Spathiocaris, Clarke. Amev. Juurn. Science. lss;:. Kputh'itirnrts, Packard. Monog. North Amer. Phyllop. Crustacea. 18S:t. Spathiocaris, Etheridge, Woodward and Jones. Rept. Committee Foss. Phyllop. 1S84. Spathiocai'is, Clarke. Neues Jahrb. fur Mia. 1884. Spathiocaris, Dames. Neues Jahrb. fur Min. 1884 Spathiocaris, Von Koenen. Neues Jahrb. fiir Min. 1884. Spathiocaris, Etheridge, Woodward and Jones. Second Rept. Committee Foss. Phyllop. 1^1. Spathiocaris, Jones and Woodward. Geol. Magazine. lss"' caris, Clarke. Devon. Faunas Ontario county. L885. Spathiocaris, Etheridge, Woodward and Jones. Third Rept. Committee Foss. Phyllop. 1885. Spathiocaris, Dames. Neues Jahrb. fur Min. 1885. Spathiocaris, Zittel. Handb. d. Pateontologie. 1886. Spathiocaris, Clarke. Geol. Succession in Ontario Co. Diagnosis. Carapace in one piece, elliptical, sub-conical and patelloid ; apex situated at or near one focus of the ellipse. The cephalic cleft begins just in fronl of the apex and slowly widens to the anterior extremity. Surface orna- mented with closely set concentric lines and usually with fine radii on the ante- rior and posterior portions. SYNOPSIS OF GENERA. MX Genus DIPTE KOC ARIS, Clarke. 1883. 1553. Dipterocaris, Clarke. Amer. Jour. Science. 1853. Dipterocaris, Etheridge, Woodward and Jones. Rept. Committee Foss. Phyllop. 1854. Dipterocaris, Jonbs and Woodward. Geol. Magazine. 1554. Dipterocaris, Etheridge, Woodward and Jones. Second Rept. Committee Foss. Phyllop. 1885. Dipterocaris, Clarke. Dev. Faunas Ontario county. 1885. Dipterocaris, Etheridge, Woodward and Jones. Thii-d Rept. Committee Foss. Phyllop. 1885. Dipterocaris, Zittel. Handb. d. Palseontologie. 1SS(J. Dipterocaris, Clarke. Geol. Succession in Ontario Co Diagnosis. Carapace in one piece, ovate in general outline; normally with an elevated dorsum and sloping sides. Each extremity is strongly notched, dividing the carapace into two hroad ala. connected hy a narrow isthmus which shows no evidence of a dorsal suture or anchylosis. Surface ornamented by concentric elevated lines or wrinkles. The true organic character of the bodies included under the genera Spathio- caris and Dipterocaris and allied forms, from the Devonian horizons of Great Britain and Europe, ha.s been a subject of some debate among recent writers. A diversity of opinion has arisen from the fact that while some of the species included under the closely related genera Peltocaris, Salter, Aptychopsis, Barrande, Discinocaris, Woodward, Aspidocaris, lleuss, Cardiocaris, Woodward, Ellipsocaris, Woodward, and Spathiocaris, Clarke, have afforded indisputable evidence of a free rostral plate cover- ing the anterior cleft, e. g., Peltocaris aptijchoides, Salter; Aptychopsis prima, Barrande; Cardiocaris Rameri, Woodward ; Discinocaris Browniana, Wood- ward ; since the original description of the species as Crustacea, Others have been found in the body Discinocaris Browniana, Woodward. chamber of a single species of Gonialites (G. intumescens) (Cardiocaris lata, Wood- ward, Spathiocaris Kmneni, Clarke, both from the middle Devonian limestones at Bicken, Westphalia). From this fact, together with the similarity of these latter bodies in many respects to the aptychi of Mesozoic Cephalopoda, and their agreement in outline with the transverse section of the body chambers in which they have been found, there is no doubt that these two species at least have had some organic connection with the cephalopoda, serving a similar Ix SYNOPSIS OF GENERA. function to the aptychi of the Ammonites. All the representatives of the genera mentioned show a degree of analogy in form and structure which, with- out accessor}' evidence, would naturally lead to their allocation to the same zoological position. The earliest of these genera established, viz., Pelto- caris, Discinocaris and Aptychopsis are of undoubted crustacean nature, as they show evidence of a cephalic or rostral plate filling the anterior cleft, and moreover, they are found at Silurian horizons where Goniatites are unknown. Referring to the Devonian species, it must be taken into consideration that they occur at horizons which are usually prolific in Goniatites, but while some may be cephalopodous, as the two species mentioned, those described by Key- serling from the Domanik-schiefer of Petschora-land, by Woodward from the black shales of Biidesheim, and those from the State of New York occur in no intimate or suggestive association with these fossils. The species Spathiocaris Emersoni has proven an abundant fossil at certain localities in the lower shales of the Portage group, but it has not as yet been seen in intimate connection with Goniatites. On the other hand it is found at an horizon in which the Phyllocarid Crustacea appear to have attained their maximum development in this country. Of the bipennate species, or those with the univalvular shield cleft at both anterior and posterior extremities (Dipterocaris, Pterocaris), we have no means of positively determining the nature, either from analogy with the aptychi of cephalopods or from similarity to any undoubted crustacean, except as shown in the genus Peltocaris, etc. With our present knowledge their crustacean affinities appear the more decided; the anterior cleft for the rostral plate, the posterior cleft for the protrusion of the abdomen, and the sides normally doping as in Peltocaris, Rhinocaris, etc. On plate 35 of this volume is given a figure representing a minute bipennate body having the outline of JJipterocaris, lying within the body-whorl of a large individual of Goniatites complanatus. The body-whorl of the shell has a width of 37 mm., the diameter of the entire shell having been as great as 75 mm.; the length of the Dipterocaris-like body is 5 mm. The specimen is from the lower Bhales of the Portage group, in which Goniatites complanatus is the most SYNOPSIS OF GENERA. lxi abundant cephalopod and furnishes the only instance observed, alter the most careful examination of the rocks, of any such association of these bodies, and also the only example of the occurrence of a body resembling Dipterocaris in these beds. If this association is not purely accidental, and if there actually existed any organic connection between the Goniatite and the enclosed body, the latter has certainly not been similar in function to the aptychi. While it is necessary to recognize the fact that of the bodies included under the genera Spathiocaris, Cardiocaris, Discinocaris, Dipterocaris, Pterocaris and Pholadocaris some are undoubtedly crustacean and others, with certainty, cephalopodous, with our present knowledge it is impossible to draw the divid- ing line between them. ORDER, DECAPOD A. Family, Carididje. Genus PAL.EOPAL M MON, Whitfield. 1880. Diagnosis. Cephalothorax not rostrate (?), keeled upon the dorsum and sides. Antennules not observed. Antennaj with very strong basal joints, exceeding in strength any of the thoracic appendages. Eye-peduncles probably short. Thoracic ambulatory appendages slender, not forcipate. Abdomen composed of six segments. Telson short, rapidly tapering and connected by a membranous expansion with the lateral caudal spines. In the midst of this caudal expansion lies a pair of thin lamellar spines articulated at their proximal extremities to both telson and lateral spines. ORDER, PHYLLOPODA. Family, Limnadiad.e. Genus ESTHERIA, Rvppell. (devonian species only.) 1846. PosidoTwmya, Eichwald. Geol. Russia. 1S49. Asmusia, Pacht. Devon. Kalk in Livlaml. bdi SYNOPSIS OF GENERA. 1852. Posidojunnya, Pacht. Ueb. Dimerocnnites. 1852. /' a, Kbtorga. <;•■'■ lt n . Karte Gouvern. Petersbourg. 1855. Estheria, Jones. Quart. Journ. Geol. Society. 1858 /• ■■, ot, Vok Helmersen. Geogn. Untersuch. Mi ttl. Gouvern. Russl. L859. Estheria, Jones. Quart. Journ. Geol. Society. I860. Asmusia, Pander. Monogr. der Saurodipterinen. LS62. Estheria, Jones. Monogr. Foss. Estherias. 1882. Estheria, Ci wikk. Amer. Journ. Science. [883. Estheria, Packard. Monogr. North Amer. Phyllop. Crustacea. Diagnosis. Carapace bivalvular, the outline of each valve being sub-circular, obliquely oval or sub-quadrate. Beaks generally anterior, sometimes sub- mit ral. Dorsal or hinge-line straight, shorter than the greatest length of the valves. Surface rarely smooth, usually with concentric lines of growth, the interstitial spaces being often ornamented with a fine punctate or reticulate sculpture. Test very thin. Genus SCHIZODI SCUS, nov. gen. Diagnosis. Carapace bivalvular, the valves readily separable along the hinge. Outline circular or ovate, narrowing posteriorly. Surface convex or depressed, elevated at the beaks which are prominent, slightly incurved, and situated anteriorly. Hinge-line equaling in length the greatest diameter of the cara- pace ; edges parallel and not gaping at either extremity. Surface ornamented by regularly concentric wrinkles. ORDER, CIRRI FED I A. Family, Balanid.e. Genus PROTOBALANUS, nov. gen. Diagnosis. Shell ovate about the basis; composed of twelve plates of which the carina is largest and most elevated. Rostrum small; lateralia five on each side ; radial areas between the lateralia broad ; scutum and tergum not known. i leneral surface depressed convex. SYNOPSIS OF GENERA. l.\ in Family, Lepadidje. Genus STROBILEPIS, nov. gen. Diagnosis. Capitulum composed of four vertical ranges of plates, having in general a trihedral form, but varying greatly in contour and size. Each plate is closely articulated to, and sometimes overlapping the next preceding The anterior extremity is terminated by a relatively large, circular, conical plate against the sides of which the first plate in each vertical range lies. In the type species, two of the four vertical ranges of plates are of about the same size, one consists of a few very small plates and the fourth is modified into a series of spines which appear to be articulated to one another at their liases and to lie opposite the range of small plates. Plates calcareous and relatively thick. Surface ornamented by fine concentric, often obsolete wrinkles of growth, and low radiating furrows and ridges, and entirely covered with minute punctse, Genus TURRILEPAS, Woodward. 1S65. 1865. Tarrilepas, Woodward. Quart. Journ. Geol. Society. 1872. Plumulites, Barrande. Syst. Sil. Boheoie, vol. i. suppl. 1875. Plumulites, Hall and Whitfield. Geol. Surv. Ohio, Palaeontology, vol. ii. 1S76. Plumulites, C. P. Rcemer. Lethasa palteozoica. 1882. Plumulites, Clarke. Amer. Journ. Science 1882. Plumulites, Whitfield. Ann. New York Acad. Sciences. 1881. Plumulites, Zittbl. Sitzungsber. d. math.-phys. Classe 'I. I-. bayer. Ak.nl. d. Wiss. 1SS5. Plumulites, Zittel. Handb. d. Paleeontologie. Diagnosis. Elongate cone-shaped bodies, composed of from four to six vertical ranges of scale-like plates, which are sub- triangular in general outline and are covered with strong, some- what elevated concentric lines. The plates of the middle range are distinguished from those of the lateral ranges by their more convex surface and median carina. (zittel.) Turrilepas Wrightianus. lxiv SYNOPSIS OF GENERA. The structure and exacl relations of these bodies still remains open to some question. As the separate plates are usually detached and isolated, it is im- possible to determine how great a variation in form may have existed among them in any given species, and, therefore, it may be that some of the plates here described as different species on account of their diversity in form, will even- tually have to be united, as being different parts of animals belonging to the same species. By Woodward and Zittel these fossils are regarded as representing the scaly peduncle of Lepadoid cirripedes similar to Lorkula and Archaolepas, and by Barrande as an elementary type of capitulum. Figures are given by Barrande and Woodward which represent the different ranges of plates constituting these bodies in approximately their normal position, but in none of them is the character of the distal extremity of the scaly covering represented. The type specimen of the closely allied genus Strobilepis (S. spinigera) has a single conical terminal plate at the distal extremity, and the entire body is probably to be regarded as a capitulum, and from analogy it would appear that the view of Barrande in regard to the nature of Turrilepas may be correct. The term Turrilepas was proposed by Woodward in 1865, the character of the fossils being analysed at some length and accompanied by satisfactory illustra- tion. It has, however, been customary among authors to accord recognition to the term Plumulites, given by Barrande in 1872, with somewhat more extended description and illustration. There seems, however, to be no valid reason why Woodward's term should not be accorded acceptance. The genus Lepidocoleus, Faber, (Journ. Cinti. Soc. Nat. V Hist.. 1886), founded upon a nearly entire specimen of the Plumulites Jamesi, Hall and Whitfield, appears to be composed of but two ranges of vertical plates of unequal size, interlocking along their basal edges for their entire length. ft Lepidocoleus jamesi. CRUST AC EA OV nil-: UPPER HELDERBERG, HAMILTON. PORTAGE AND CHEMUNG GROUPS. DESCRIP I [( >NS < »F SPECIES. TIE^ILOIBIT^ CALYMENID^E. CALYMENE, Brongniart. 1822. Calymene platys. PLATE I, FIGS. 1-9; am. PLATE XXV, Hi, 1 ' lymene platys, Green. Monogr. Trilob. of North America, p. 32. 1832. Calymene platys, Hall. Descrip. New Species of Fossils, etc., p. 54. [861. Calymene platys, IIall. Fifteenth Kept. N. Y. state Cab. Nat. Hist., p. S2. 1862. Calymene platys, Hall. Illustrations of Devonian Fossils, pi. i, figs. I -9. 1876. General Form and Proportions. Body elongate-sub-ovate, widest anteriorly and tapering rapidly to the posterior extremity. Surface convex, laterally deflected, sub-equally trilobate. Length to width as 1.7 to 1. Cephalon short and broad, outline crescentic ; length to width as 1 to "J. 5. Margin on the anterior extremity thickened, slightly produced, reflected and broadly infolded to the doublure. Epistomal surface narrow. Genal angles rounded, not produced. Frontal area narrow and obscured by the overarching glabella. Facial sutures having their origin on the Literal margins just in front of the genal angles, passing inward with a slight curve nearly parallel to the posterior PALEONTOLOGY OF NEW YORK. margin, to the eye, thence forward at nearly right angles, to the frontal mar- gin, where they pass over upon the doublure, gradually approximating, and terminating on the epistomal margin. These lateral branches are united by the transverse frontal suture just below the frontal margin, thus leaving a free median frontal plate. Glabella large, trapezoidal or sub-quadrate in outline; widest posteriorly, where the width nearly equals the length of the cephalon ; convex, tumid on the frontal lobe; dorsal and anterior furrows strong and deeply impressed; lateral furrows in three pairs, the first of which is faint and almost obso- lete, the second short and broad, the third longer, curved slightly forward, bifurcating near its anterior extremity, the posterior branch having a retral bend. Frontal lobe sub-hemispherical, gibbous ; second and fourth pair of lateral lobes transversely pyriform, the latter much the stronger and having a diameter equal to one-fourth the posterior width of the glabella; third pair inconspicuous, and seen only under favorable preservation. Occipital furrow narrow on the axis, widening on the cheeks; occipital annulation broad, elevated, becoming flattened on the cheeks toward the genal angles. Cheeks broadly sub-triangular, depressed convex ; free portions triangular, small. Eyes small, situated somewhat anteriorly; palpebral lobe depressed, broad, making the visual surface distant from the glabella; palpebral furrow deep and strong. Thorax sub-equally trilobate, margins sloping posteriorly. Length and width equal. Axis broadest at about the fifth segment, thence tapering evenly to the pygidium. Pleura deflected along the fulcrum at about one-third their width from the axial furrows. The thirteen segments have a slight double curve upon the axis, bending backward at a short distance from the axial margins, thence forward again CRUSTACEA. 3 along the axial line. Upon the pleura' the segments are grooved, the ante- rior limb of each being small and becoming obsolete on the beveled planes of articulation. Pygidium spherically sub-triangular, truncate and strongly emarginate on the posterior bonier. Length to width as 1 to 1.3. Axis broad, rapidly narrowing and ending abruptly in a blunt elevation within the posterior border; its terminal portion is flattened above, and from its apex a low ridge passes over the post-axial area. Axial anima- tions six. Pleura broad, and abruptly deflected. Anterior margins strongly beveled by the articulating planes, and meeting the lateral margins at an angle of ninety degrees. Pleural annulations lour, flattened near the margin and sometimes showing a tendency to bifurcato . Hypostoma sub-quadrate; lateral margins strongly incurved, posterior border emarginate. Anterior angles auriculate, margins thickened and slightly reflexed ; centrum elevated, sharply carinate. Surface Ornamentation. The east of the external surface of a nearly entire individual, which served as Dr. Green's type of the species, shows faint tubercles over the glabella and free cheeks, but these appear to be obsolete upon the occipital annulation and the rest of the body. Dimensions. The smallest individual of this species which has been observed is the type specimen. It affords the following measurements: Length 63 mm.; width 45 mm. The largest individual observed measures: i: ily. lalon. Thorax. Pygidium. Length 130 mm. 30 mm. 75 mm. 25 mm. Width 75 mm. 75 mm. 70 mm. 30 mm. Fragments of still larger individuals are sometimes found, a single pygidium from the Upper Helderberg limestone of the Kails of the Ohio measuring 45 mm. in length and 35 mm. in width, indicating an individual of quite 1 PALEONTOLOGY OF NEW YORK. colossal size, which, judging from the proportions afforded by other specimens, must have measured upwards of 200 mm. in length. Observations. There is a striking similarity in the specific details of Caly- mene platys, Green, and those of Calymene Niagarensis, Hall. Indeed upon the basis of any external feature, further than the great difference in size attained by the two species, it might be difficult to establish the specific limitations. Here, however, the notable diversity in the hypostomas proves of great import- ance. In Calymene Niagarensis the hypostoma is elongate, with the anterior margin entire, lateral margins broadly incurved and reflexed, sharply and deeply emarginate behind, centrum convex and rounded, bounded by a strong sulcus at its base, and bearing a conspicuous furrow on its posterior portion. In respect to size, the largest individuals of Calymene Niagarensis will not exceed "in nun. in length, and the smallest observed of Calymene platys do not fall below 65 mm. in length, and as noticed, may have attained a length of 200 mm. Murchison has figured a large individual of Calymene Blumenbachi, Brongniart, which has a length of about 100 mm. (Silurian System, pi. vii, fig. 6), and Angelin one of Calymene spectabilis, Angelin, 125 mm. in length (Palueontol. Scandinavica, pi. xix, fig. 5). It is a noteworthy fact that the last known representative of this characteristic Silurian genus, Calymene, should have attained dimensions which surpass those of any of its known predecessors. Distribution. Upper Helderberg group. In the Schoharie grit, at Schoharie, Schoharie county, and Knox, Albany county. In the Upper Helderberg lime- stone, .it Falkirk and Clarence Hollow, Erie county, and Falls of the Ohio. IIOMALONOTUS, Kcenig. 1825. HOMALONOTUS MAJOR. PLATE V A, FIG. 1. hu major, Whitfield. Bulletin Amer. Mus. Nat. Hist., vol. i, No. 6, Art. xi, p. 193, pi. xxii. 188H. Tie' Cephalon and anterior portion of the Thorax have not been observed. Tie' Thorax has the lateral margins sloping somewhat less rapidly than in Homalonotus Dekayi, and very much as in H. delphinocephalus. Surface flat, CRUSTACEA. 5 abruptly deflected for nearly an inch at the margins, and wry indistinctly trilobate. Axis very broad, width more than two-thirds the width of the body. Seg- ments broad and flattened, abruptly deflected at the anterior and posterior margins and separated by very narrow transverse furrows, which are scarcely distinguishable for their entire length, but arc mosl noticeable at the margins of the axis, where lie the deep depressions to the leg-bases or visceral supports. The deep transverse furrows along the middle of the segments are con- spicuous and most distinct toward the lateral margins of the thorax and upon the broad beveled articulating planes. The same liability to error in regard to the anterior and posterior limits of the segments is noticeable in the lower surface of this species as mentioned in the description of Homalonotus Dekayi. The segments are evenly curved over the axis and posteriorly deflected toward the margins. Ptgidium elongate-sub-triangular. Surface depressed-convex, sloping evenly to the margins. Axis well defined and composed of ten annulations, the articulating ring being the posterior half of the apparent last thoracic segment. These annu- lations are broad, flat or slightly rounded, and arc nearly transverse, with a slight forward bend over the axis. The pleura bear seven or eight distinct annulations. Posterior margin slightly produced. In one specimen the posterior extremity is broken away, its extension being indicated by the slope of the lateral margins, and in the other it has been displaced and forced to one side. Surface of the test characterized by tubules of comparatively small size, which have left their impressions on the cast of the lower surface. Observations. Of this remarkable species of Homalonotus hut two examples have been discovered. The smaller of these, and somewhat better preserved specimen, showing the pygidium ami five thoracic segment-, has served as the type of the original description, and the other which is here figured 6 PALEONTOLOGY OF NEW YORK. in further illustration of the species, retains the pygidium and indications of ten segments. The former fragment has a length of 155 mm., and a width of bin mm.; the latter a length of 220 mm., and a width of 150 mill. These specimens were obtained by Mr. Louis Bevier, of Marbletown, Ulster county. They are beyond doubt representatives of the largest known of this genus, and were two of the largest known trilobites. Mr. Whit- field estimates the entire length of the specimen described by him, as restored from proportions furnished by other species, at fifteen and one-half inches. With the figure of the larger specimen here given is an outline restoration, the data for which have been derived from a careful summary of measurements of species in which the pygidium is strongly annulated. The result indicates an individual measuring 374 mm. or 14.95 inches in length, and 145 mm. or 5.8 inches across the base of the cephalon. This outline will help the student to realize, better than maybe done from the figure of the fragment alone, the colossal size attained by this species. Fragments of Homalonoti of large size have been described by other authors. Salter has referred (Paheontogr. Soc, vol. xvii, p. 109) to a large specimen of Homalonotus rudis, winch he estimates may have been a foot in length when entire. Beushausen has figured a pygidium of Homalonotus gigas, F. A. Rcemer, from the Spiriferen-sandstein of the Hartz Mountains (Beitr. zur Kenntn. Ober- harz. Spirit'. Sndst'ns, pi. i, tig. 1. 1884), which measures 94 mm. in length, and though proportionally narrower than the pygidium in H. major, represents an individual probably not much shorter than the one here illustrated. It is noteworthy that this large species, Homalonotus gigas, is from a lower Devonian formation, not widely differing in age from the horizon of Homalonotus major. In the distinctly annulated pygidium, Homalonotus major agrees with the major- ity, if nut with all the species of Homalonotus known from Silurian and lower Devonian horizons, and in this regard differs from Homalonotus Dekaiji of the Hamilton group, in which the annulal ions are faint or obsolete. Distribution. The locality of these fossils as given by Mr. Bevier, for the specimen here figured, is "Lower Oriskany, bank of 4th Binnewater, Rosendale, Ulster county;' and lor the type specimen, "Upper Oriskany, Cranberry Dam, 5th CRUSTACI. A. 7 Binnewater, Ulster county." This reference is probably correct, as the matrix of the larger trilobite shows a well-defined specimen of Spirifera arena . an Oriskany species, and Mr. Whitfield has mentioned the occurrence of a young individual of Strophodonta magnified upon the smaller specimen. HOM IL0N0TUS DeKAYI. PLATE II, FIGS 111 i PLATE III, FIGS l 5; l'l.vii; l\, FIGS. l-fi; ISO PLATE V, PIGS. 1-10. Dipleura h iayi, Green. Monog. T b N irth '. ■■ ca, p. 79. IS32. Nuttainia sparsa, Eaton. Geological I , p. 34. is Dipleura Dekayi, Vandxem. Geologj of New Fork. Survey G .' I I, fig, 1. IS42. Dipleura Dekayi, Hall. Geologj of New York. Survey Fourth Geol. Hist., p. 205, fig. I. Bmnalonntus Dekayi, Emmojjs. Manual of Geology, pp. 146, > IT. fig . 134, 135. I860. Hbmalonotus Dekayi, Hall. Fifteenth Rept. N. Y. State Cab Mai H t., p. 113. 1862. Homalonotus Dekayi, Hall. Illustrations of Devonian F ii, iii, iv, v. 1 st»;. General Form and Proportions. Elongate, linguiform, anterior and posterior extremities produced and sub-angulate ; lateral margins nearly straight and approximating posteriorly. Length to width about as 2 to I. Surface depressed-convex or flattened, obscurely trilobate, abruptly de- flected along the lateral margins. Cephalon broadly sub-triangular in outline, posterior side the longest : angles rounded. In the usual condition of preservation the lateral margins approach each other at an angle of ninety degrees, making, at the basal margin, an angle of forty-five degrees. With the retention of normal convexity, the shield is nearly equilateral. Length to width as 1 to L.9. The surface is normally depressed-convex or flattened, deflected beneath the ocular nodes; trilobate; frontal and lateral areas narrow, the former produced into a short prora. The facial sutures take their origin on the lateral margins of the doublure in front of the genal angles and pass inward, parallel to the posterior margin of the cephalon, to the eye, thence forward with a broad curve inward to the anterior margin at the base of the prora, bending tin <■ ce on to the epis- tomal doublure, meeting at its inferior margin. The branches of the facial suture are united on the upper surface of the prora by a straight transverse 8 PALEONTOLOGY OF NEW YORK. frontal suture, thus Leaving a free median plate upon the epistoma, which is elongate-sub-triangular in outline, attenuate at the apex, and recurved at the base which forms the anterior portion of the prora. Glabella sub-quadrangular, broadest behind ; lateral margins slightly incurving; angles rounded; length equal to three-fourths the length of the cephalon. Surface depressed-convex. Lateral furrows in three pairs, the first two of which are short, extending about one-fourth the distance across the glabella, and are perpendicular to the margin. The third pair near their proximal extremities are bent backward. The third or posterior lobes are the strongest, the anterior or frontal lobe having about the same strength as each of the first two pairs. Rarely in young individuals, and only under favorable preservation, are these furrows and lobes to be seen, since they become obsolete at an early stage of growth." Cheeks. The movable portions are flattened, and when normally preserved are abruptly deflected. They have rarely been observed isolated, although the cephalic shield is not infrequently seen with these parts wanting. Eyes situated at the summit of strong, elevated nodes, each of which occupies nearly one-third the entire surface of the cephalon. These nodes are bounded by low sulci separating them from the glabella, occipital ring and lateral area. Visual surface small, lunate, covered with minute homo- corneal lenses, of which about one thousand have been counted in each eye of a small individual. Palpebral lobe capping the visual surface, and sloping evenly and abruptly to the palpebral furrow. Thorax broad; length equal to the width. Surface depressed-convex, scarcely trilobate ; lateral portions abruptly deflected ; margins approximating pos- teriorly. Axis broad, making two-thirds the width of the body. Pleura narrow, deflected along their median line. Each of the segments is broadly rounded or flattened upon the axis, lb" posterior margin infolding over the articulating ring of the next succeeding segment. These articulating rings are exposed even where the CRUSTACEA. 9 animal has been preserved in an extended condition. In casts of the under surface, the usual mode of preservation in the sand} shales of the central counties where individuals are most abundant, the transverse median groove upon the segments appears very broad and deep, and may be misleading in determining the true limits of the segments. In such specimens, along the low and indistinct longitudinal axial furrows, there are rows of double depressions or pits at the anterior and posterior margins of adjacent seg- ments, which are suggestive of the depressions left by the visceral sup- ports or basal joints of natatory appendages; but in position they are not homologous with those observed in Phacops rana and other species. The transverse groove is continued upon the pleura', passing over the broad beveled articulating planes, but becoming obsolete before reaching the mar- gin. In specimens where the crust is retained, this furrow is visible only as a sharply impressed line. Pygidium. Outline sub-triangular : length and width equal, interior margin with a forward curve; lateral margins nearly straight, with an upward curve near the posterior extremity, which is produced into a sub-spatulate exten- sion. Surface convex, faintly trilobate. The angle of convergence of the lateral margins is nearly ninety degrees and the anterior basal angles about forty-five degrees each. The articulating ring and furrow are conspicuous. The axis tapers rapidly, becoming obsolete before reaching the posterior margin. Ten annulations may be counted upon it, and eight upon the pleura. These annulations are rarely visible upon the dorsal surface except in young individuals and become obsolete in mature animals, where traces of them can be seen only in casts of the under surface. Hypostoma sub-quadrate, auriculate at the anterior angles, emarginate on both anterior and posterior margins ; centrum low, convex : posterior sulcus and posterior lateral pits conspicuous; margins thickened, not reflected. Surface pustulose. Surface Ornamentation. The surface of the test on its more prominent portions is marked by the openings of large vertical tubulipores. On casts in PALAEONTOLOGY OF NEW YORK. of the Lower surface impressions of the projecting edges of those tubules are also visible. Between these openings may be seen minute pittings which are the openings of .-mailer tubules. Dimensions. An average example affords the following measurements: Body. Cephalon. Thorax. Pygidium. Length 156 mm. 40 mm. 73 mm. 43 mm. Width 75 mm. 75 mm. 73 mm. 48 mm. The largest entire individual observed has a length of 220 mm. and a width of 100 mm.; the smallest a length of 10 mm. and a width of 6 mm. Observations. Homalonotus Dekai/i, the latest and most prolific representative of the genus in America, differs from the Homalonoti 'of the earlier Devonian and the Silurian, both in this country and Europe, in the obsolescence of the annulations of the pygidium at maturity. It is an abundant fossil in the sandy shales of the Hamilton group of the central counties of the State where it is usually preserved in the form of casts. West of Cayuga county it is of much rarer occurrence and appears to be mostly confined to the shales above the Encrinal limestone. In Genesee and Erie counties it is very seldom met with, and in the eastern outcrops of this formation in Schoharie and Albany counties it is not abundant. Distribution. Hamilton group. In the Marcellus shales on Flint Creek, Ontario county: in the Hamilton shales at Bear's Gulf, near Summit, Schoharie county : Cazenovia, Leonardville and Hamilton, Madison county ; East Worcester and elsewhere, Otsego county : Pompey Centre, Pratt's Falls and Delphi, Onon- daga county; Bellona, Yates county; Hopewell and West Bloomfield, Ontario county; Tichenor's and Menteth's* Points, Canandaigua Lake; Darien, Genesee county: Hamburgh and Eighteen-mile Creek, Erie county. ■■■ -Thi.s name us used in the previous publications on the Palaeontology of New York, and a? spelled by the original owner of the propertj on ( ianandaigua Lake, was Montt ill/. It is now understood that its present owner lia-< changed the - pelling of the name to Mi nteth. CRUSTACEA. II HOMALONOTUS \' A\ I \ i:\ll. PLATE V B, FIGS. I, -•. Homalonotus Vanuxemi, Hall. Palaeontology N. Y., vol. iii, p. 352, pi. Ixxiii, figs. 9-14. 1859 This species was described from very meager material consisting of detached pygidia and a fragment of the thorax. Although it has proven to be a fossil of rare occurrence, more complete specimens have since been obtained, which make the introduction of the species in this place important both for the pur- pose of extending the knowledge of its characters and of comparison with the Devonian Homalonoti. The very large fragment here figured consists of the pygidium and eleven segments of the thorax, the latter part being considerably weathered on the left side and over the dorsum. It was obtained from a quarry in the Lower Helderberg limestone at Kingston, Ulster county, and is so preserved as to retain its normal convexity. This specimen shows that the species approximates very closely Homalonotus delphinocephalus, Green, differ- ing from the latter, however, in the features pointed out in the original descrip- tion, namely, the greater number of annulations in the pygidium ; the former having upon the axis eleven or twelve, including the articulating ring, the latter nine or ten ; and upon the pleura? the former ten and the latter eight. The pleural slopes of H. Vanuxemi appear also to have been considerably broader. The cephalon, which is restored in the figure from a fragment (the only example yet observed) taken from the limestone at Port Jervis, Orange county, is con- siderably produced at the anterior extremity, even more than in H. delphinocephalus or H. Dekayi. Just in front of the glabella is a, gentle and broad depression, giving to the frontal prolongation a shovel-shaped surface. Tin' glabella is generally smooth, and regularly convex, unlike that of the Niagara species, which often shows a lobate character. That the Lower Helderberg species attained very considerable size is shown by the restoration of the missing parts of the figured specimen, as given upon the plate, indicating that the animal reached a length of 275 mm., or eleven inches. PALEONTOLOGY OF NEW YORK. BRON TEIDJE. B U 0 N T E U S , Goldfuss. 1843. Bronteus Tullius, n. sp. l'l.Aii: \in a, figs, a 16. Cephalon and Thorax unknown. Pyqidium flabellate, comparatively small; outline semi-ovate, anterior margin rounded and incurved toward the axis. Length to width as 2 to 3. Surface depressed, gently elevated and convex about the axis, becoming concave toward the margin and slightly reflexed at the edge. Axis short, about one-fourth the length of the shield; width about twice the length. Outline broadly trigonal. Articulating ring prominent, but not well preserved in the type specimen. No annulations visible. Pleura very broad and bearing fifteen broadly flattened and simple annula- tions. Of these the widest lies in the axial line with seven on either side. These annulations are nearly straight, radiating evenly from the margins of the axis and separated by narrow, sharply impressed sulci. Both the annula- tions ami sulci become obsolete before reaching the border, the posterior ono not extruding so far as the anterior. The border is ornamented with a single row of minute spinules, numbering about twenty-five along the termi- nal margin of each annulation : these measure scarcely 1 mm. in length and are inclined slightly upward. Doublure very broad, extending fully halfway across the \>\ iridium. Test extremely thin; the portions retained are strongly and regularly pustulose, the pustules on the ribs apparently extending to the margin. The doublure is marked by distant, sub-parallel, anastomosing, lamellose lines. The type specimen has a length of 15 mm. and a width of 21 mm. Another specimen of limestone from a, different locality bears the epis- tomal doublure of some trilobite. This fragment is broadly convex and prominent over the central area and constricted toward the sides, and is quite unlike the frontal doublure ,,f any associated species of crustacean, but has CRUSTACEA. 13 the outline and contour usual in this part of Bronteus. It may, therefore, with propriety, be regarded as belonging to this species. Observations. This species is represented only by the two fragments described, both of which were discovered by Professor S. (•. Williams, of Cor- nell University, by whose kindness this notice appears. Unusual interest attaches to it as the first representative of the genus Bronteus discovered in the Devonian of America, although the genus is abundantly represented in the Devonian horizons of Europe. A dose relationship is observable in the species Bronteus Tullius and B. granulatus, Goldfuss, from the middle Devonian of the Eifel and the lower upper-Devonian limestone of the [berg-Winterberg terrane. This similarity consists in the number and contour of the ribs and the ornamentation of the dorsal surface and doublure. The fauna of the Iberg lime- stone is characterized by a vcvy abundant development of the species Rhyn- chonella cuboides, Sowerby, of which species the American representative R, venustula, Hall, occurs only in the Tully limestone, the formation from which Bronteus Tullius has been derived. The row of minute spinules along the pos- terior margin of the pygidium of our species shows its relationship to the comparatively limited group of forms following the type of Bronteus thysanopeltis, Barrande. This group includes at present the following species, viz.: B. thysa- nopeltis, Barrande, B. Clementinas, Barrande, B. acanthopeltis, Schnur, />'. Barrandii, Hebert, B. Waldschmidti, von Kcenen, B. Raphaeli and B. Trutati, Barrois, and B. Tullius. In Bronteus Tullius these spines are much more minute than in any other of the species mentioned. Kayser* has observed that this group of Bronteus stands in the same relation to the Silurian forms of the genus as the genus Cryphceus does to the normal forms of Dalmaniles, i.e., those after the type of D. Hausmanni. So far as known, it is limited to Devonian faunas, and is appropriately designated by the term Thysanopeltis, applied to this variation by Corda (Prodrom. Monog. Trilob., 1847), and revived by Barrois (Ann. de la Soc. Geol. du Nord, p. 131, 1886), with sub-generic value. Distribution. Hamilton group. In the Tully limestone, Kingsley's Hill, north- east of Otisco, and Borodino, Onondaga county. *J31teste Devon- Ablag des Harzes, p. 255. 1878. 1 i PALAEONTOLOGY OF NEW YORK. I* II ACOPID^E. PHACOPS, Emmrich. 1839. Phacops cristata. PLATE VI, FIGS. US, 16-29; AND PLATE VIII A, FIGS. 1-4. 1 1 istata, Hall. Descr. New Species of Fossils, etc., p. 67. 1861. Phn, .Hall. Descr. New Species of Fossils, etc., p. 67. 1861, a, II u.l. Fifteenth Rept, N. Y. State Cab. Nat, Hist., p. 95. 1862. . Hall. Fifteenth Rept, N. Y. State Cab. Nat. Hist., p. 95. 1862. tta, Hall. Illustrations of Devonian Fossils, pi. vi, tigs. 1-13, 16, 17. 1876. Phacops bombifrons, Hall. Illustrations of Devonian Fossils, pi. vi, fig-s. 18-29. 1876. ral Form ami Proportions. Outline elongate, sub-elliptical. Length to width as 1.7 to 1. Lateral margins sub-parallel. Surface depressed-convex, echinate along the axis. Cephalon broadly ovate or nearly semi-circular in outline; length to width as 1 to 7. Frontal area obsolete, lateral area narrow, margins broadly thickened by doublure, and produced at the genal angles into short blunt spines, which air directed slightly upward and inward. Sub-marginal sulcus strong, ex- tending to within a short distance of the genal extremities, bearing on the lateral margins, behind the epistoma, ten or eleven crenulations which diminish in size backward. Epistoma comparatively narrow. Facial Sutures not observed. Glabella broad, convex, sub-pentagonal, tumid (generally flattened in ex- am pic- from the Schoharie grit), protuberant, extending for one-third its length beyond the frontal margin. In favorably preserved specimens, either of the external or internal surface, traces may be seen of the first and second pair of lateral furrows ; third lateral furrows deeply impressed but undefined, making the third or basal lobes of the glabella very obscure. Antero-lateral furrows may sometimes be discerned in front of the first pair of lateral fur- rows, and parallel to the palpebral sulci. Occipital furrow broad and deep; occipital ring elevated and conspicuous. CRUSTACEA. 15 Cheeks depressed, sloping abruptly to the margins, broad and flat aboul the genal angles, echinate at the extremities. Eyes large, scarcely reaching the height of the glabella. Visual surface lunate. Corneal lenses, in the normal individual, abundant and subject to considerable variation in number. Beginning at the posterior angle of the visual surface and following the rows diagonally, parallel to the lower posterior margin, the number of rows is generally eight, in no observed instance ex- ceeding nine and rarely falling to seven. In Phacops rana the number of rows is usually nine, often ten, and rarely eleven or eight. In Phacops cristata the number of lenses averages about sixty, varying between the limits forty- seven and eighty-two. the higher numbers being reached only in examples from the Upper Helderberg limestone. Palpebrum scarcely prominent ; strength of the palpebral lobe varying with the elevation of the eye. Thorax. Margins sub-parallel, tapering slightly backward. Surface depressed- convex, and strongly trilobate. Length to width as 1 to 5. Axis convex and evenly tapering. Pleura flattened above and abruptly deflected at about one-third their width from the axial furrows. The segments show a slight retral curve on the axis near the margins, bending forward over the axial line: dichotomous on the pleura?, the anterior limb becoming obsolete at the fulcrum by the development of the lateral articulating planes. Pygtdium. Outline transversely semi-elliptical. Length to width as I to 2. Surface convex, depressed on the pleurae. Axis prominent, tapering to a broad, obtuse and obscurely defined termina- tion within the posterior margin ; in well-preserved specimens it bears five or six annulations, and behind these three or four pairs of tubercles or unde- veloped annulations, which are separated by a low axial depression. The pleura each bear five, and traces of six dichotomous annulations. all be- coming obsolete before reaching the margin. In casts of the under surface, which is the usual condition of preservation in the Schoharie grit, and often 16 PALEONTOLOGY OF NEW YORK. in the Upper Helderberg limestone, the bifurcate character of the pleural annulations is notalways readily discernible. Htpostoma elongate-triangular. Length to width as 1 to 1.25. Antero-lateral angles strongly auriculate. Anterior margin with a gentle forward curve, lateral margins tapering evenly to the posterior extremity, which bears a short medial spine with a smaller spine on either side. Centrum convex; posterior sulcus conspicuous; postero-lateral depressions faint; a pair of circular depressions near the anterior angles. Surface Ornamentation. The surface of the glabella is covered with low, closely set tubercles, traces of which seldom appear in the casts of the under surface. The other portions of the shield are smooth, except the genal angles which are faintly pustulose, each bearing a short, stout spine. At the center of the occipital ring is a similar, though consider- ably stronger spine, the first of a row of spines, twelve in number, ex- tending along the axial line to the pygidium. In young individuals these spines are low and inconspicuous, and are usually accompanied by a few faint tuberculations upon the axis. The surface of the pygidium is nearly or quite tree of ornament in the adult, and faintly pustulose in the young individual, the pustules being coarser upon the axis and finer upon the pleurae, where they are arranged in single rows upon each ridge of the annulations. Dimensions. Entire individuals referable to the type form of this species, are very rarely found, although fragments are of frequent occurrence. A single nearly entire example from the Schoharie grit has the following dimensions: Body. Cephalon. Thorax. Pygidium. Length 47 mm. 14 mm. 23 mm. 10 mm. Width 26 mm. 26 mm. 20 mm. 20 mm. An entire cast of the lower surface from the Corniferous limestone gives the following measurements : Body. Cephalon. Thorax. Pygidium. Length 75 mm. 19 mm. 43 mm. 13 mm. Width 38 mm. 38 mm. 35 mm. 24 mm. These dimensions may be regarded as those of normal full growth. CRUSTACEA. 17 Observations. Specific Diagnosis. The diagnostic characters of this species are very clearly defined, and may be summarized as follows: (a) the axial row of spines extending as far as the pygidium, (l>) the short, stoul spines on the genal angles, (c) the strongly protuberant glabella, (d) the com- parative absence of tuberculations, except on the glabellar surface, (e) the ten or eleven crenulations upon each side of the sub-marginal furrow of the cephalon, (f) the dichotomous annulations of the pygidium. In the summary of these features Phacops cristata differs from any species known outside of the State of New York, and therefore cannot be satisfactorily compared with any extra-limital forms in the United States. Phacops fecundus, Barrande, from the F, G and H etages of Bohemia, and the lower and middle Devonian of the Eifel, Westphalia and the Hartz, presents a striking similarity in outline, in the protuberant glabella and the grooved pygidial annulations. Phacops Logani, Hall, from the Lower Helderberg group, hears a pygidium with similarly bifurcate ribs and obtusely terminated axis, and a cephalon with minute spines on its genal angles, but it is distinguished from Ph. cristata by the con- spicuous nodes along the margins of the axis of the thorax, the stronger tuber- culatum of the surface, and the absence of an axial row of spinules. Phacops Trajanus, Billings, also from the Lower Helderberg group, bears bifurcate annu- lations on the pygidium. hut as this species is incompletely known, its further resemblances to Ph. cristata cannot he indicated. As described and limited in the original description (loc. cit.) Phacops cristata was made to include all the forms of this genus occurring in considerable abundance in the Schoharie grit. and these exclusively, with the exception of a single specimen from the Upper Helderberg limestone at the Indian quarries, Onondaga county. The species Phacops bombifrons was erected at the same time for certain cephalic shields and pygidia from the Upper Helderberg limestones, in which a degree of similarity to Phacops cristata was acknowledged, but in which a more prominent and pro- tuberant glabella, wider occipital furrow, narrower palpebral sulcus and stronger palpebral lobe, were regarded as distinguishing characters. With due allowance made for differences in the mode of preservation in the sandstone and lime- stone of the Upper Helderberg, the specific identity of forms referred to 18 PALAEONTOLOGY OF NEW YORK. Phacops bombifrons with Phacops cristata, with the more abundant material now accessible, appears to be indisputable. There remains, however, a form of Phacops, abundant in nearly all the outcrops of the Corniferous limestone in the State, which it was not intended to include under the original diagnosis of Phacops bombifrons, and which has hitherto remained unnoticed in any published description, or has been tacitly referred to the species Phacops rana. A careful examination has proven that Phacops rana occurs with extreme rarity, if ever, in this formation, and that the specific affinities of these abundant individuals are much too close to Phacops cristata to justify their recognition as an indepen- dent species. They may be tentatively regarded as a prolific variety of Phacops cristata, under the following designation. Phacops cristata, var. pipa, n. var. PLATE VIII A, FIGS. 5 [8. The essential points of difference between this form and the normal Phacops cristata, are the following: (a) greatly inferior size, (b) absence of the axial row of spines, (c) smaller spines at the genal angles, (d) fewer annulations upon the pygidium, (e) smaller number of corneal lenses, varying, as ascertained from measurements of a large number of specimens, from twenty-three to forty-five for each eye. They agree with Phacops cristata in (a) general proportions, (b) gibbosity of the glabella, (c) presence of the genal spines, which though sometimes faint may always be detected, (d) crenulated sub-marginal sulcus, (e) obtuse termination of the axis of the pygidium, (f) dichotomous annula- tions on the pygidium, (g) similar surface ornamentation. A single pygidium of this variety from the decomposed Corniferous chert of Ontario county, is of exceptional interest as showing on a cast of the inferior surface seven pairs of muscular impressions just within the margins of the axis. The dimensions of an average entire individual are; length 26 mm.; width 10 mm. The smallest observed has a length of 12 mm., and a width of 7 mm. Distribution. Phacops cristata. Oriskany sandstone : Cayuga, Province of Ontario, associated with Dalmanites anchiops, Green, Spirifera arrecta, Hall, Streptorhijnchus (Orthis) hipparionyx, Vanux., Rensselmria ovoides, Hall. Upper Helderberg group : in the Schoharie grit, near Clarksville, Albany county; Schoharie, Schoharie county. CRUSTACEA. 19 In the Corniferous limestone at the Indian quarries, Onondaga county; East- man's quarry, Waterville, Oneida county ; Howell's quarry, Lime Rock, Genesee county. Variety pipa. In the Corniferous limestone everywhere; especially abundant in the central and western outcrops al Waterville, Oneida eounty; Phelps and Clifton Springs, Ontario county ; LeRoy and Lime Rock, Genesee county; Clarence and Williamsville, Erie county, and in the boulders of decom- posed chert in Ontario county; Falls of the Ohio. Also at Walpole and North Cayuga, Province of Ontario. Phacops rana. PLATE VII, FIGS. 1-11 ; PLATE VIII, FIGS. 1-18; and PLATE VIII a, FIGS M-8S. Calymene bufo, var. rana, Greex. Monograph of the Trilobites of North America, p. 42. 1832. Calymene bufo, Hall. Geology N. ¥., Part, iv, p. 201. 1843. (ati/meite bufo, Owen. Geolog. Exploration of a pari of Iowa, Wis. and 111., p. 71. pi. xii. 6g. 1. IS-H. Phacops bufo, Emmons. Manual of Geology, p. 138, fig. 124 (6). 1860. Phacops rana, Hall. Descriptions New Species of Fossils, etc., p. 55. 1861. Phacops rana, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p 93. 1862. Phacops rana. Meek and Wokthen. Geol. Surv. 111., vol. iii., p. -'.47, pi- xi, tigs, la-e. 1868. Phacops rana, Nicholson. Palaont. Province of Ontario, p. 123. figs. 5, 6a. 1873. Phacops rana, Hall. Illustrations of Devonian Fossils, pi. vii, figs. 1-11 ; yiii. tigs. 1-17. 1S7C Phacojis rana, Whttfield. Geology of Wisconsin, vol. iv. p. 339, pi. xxyi. Hl.'-s 17-1'.'. 1882. Compare Phacops rana, Walcott. Palseont. Eureka Districl : Monog U.S. Geol. Suvv., vol. viii. p. 207. 1SS4. General Form and Proportions. Outline elongate sub-oval ; greatest width (measured at the posterior margin of the cephalon) to axial length as I to 2. The cephalon, thorax and pygidium are to one another in length as 1.5 to 2 to 1. Thoracic margins straight, sub-parallel, gently converging posteriorly, connecting the curves of the cephalon and pygidium, which are approxi- mately arcs of large and small circles respectively, the former with its center upon the occipital ring, the latter central upon the eighth thoracic segment. Cephalon arcuate, sub-semicircular, the regularity of the outline interrupted by the slight protrusion of the glabella and the genal extremities. Frontal margin obscure, concealed by the overhanging glabella ; lateral edges faintly marginate and rounding to the obtuse genal angles: occipital margin nearly straight, bending backward on the axis. Occipital annulation strong, and equal in size to the segments of the thorax; occipital furrow narrow and becoming obsolete upon the cheeks. 20 PALEONTOLOGY OF NEW YORK. Facial Sutures very rarely discernible. Occasional examples, in unusually perfect state of preservation and favorably weathered, or compressed in such manner as to slightly separate the eephalon along these lines, show that they take -their origin on the lateral margins just in front of the genal angles, pass along the posterior edge of the visual area, thence forward along the margin of the palpebrum, following the frontal furrow of the glabella until they meet, thus taking the normal direction for the facial sutures in the Phacopida. It is probable thai tin' separate parts of the eephalon, in all stages of growth; are virtually anchylosed along these lines, as the cheeks are rarely, if ever, found detached. Glabella large, gibbous, filling all the space between the palpebral lobes, and separated from them l>y deep furrows. Outline sub-pentagonal; greatest width anteriorly. Transverse lateral furrows three on each side, of which the first two are obsolescent, often discernible only on casts of the under surface. In well-preserved specimens their existence is indicated by obscure depressions in the ornamentation of the surface. The third pair of trans- verse furrows is very strong, extending entirely across the posterior limb of the glabella, making a narrow annulation in front of the occipital ring. In favorably preserved specimens there are faint indications of short, longi- tudinal furrows parallel to the ocular sulci, and in front of the first pair of transverse glabellar furrows. Cheeks abruptly sloping to the margin nearly in a, plane with the visual " area, narrowing anteriorly and reflected ventrally to form the doublure. This doublure or infolded margin is broad at the genal angles, narrowing somewhat beneath the eyes, thence forward, widening beneath the glabella to form the broad depressed epistoma. A strong sulcus passes along the doub- lure just below the margin, widening into a broad groove upon the epistoma, and toward the genal extremities its margins bear five or six crenulations which bee, une finer as they approach the angles. Eyes prominent, scarcely reaching the height of the glabella in uncom- pressed specimens. Palpebral lobe strong, scarcely as high as the palpebrum and extending to the occipital furrow. Palpebrum crescentic. Visual area CRUSTACEA. 2] lunate, separated from the cheek by a strong, smooth sulcus; corneal lenses abundant, scleral cavities generallj hexagonal ; the number of lenses varying greatly with age. Counting from the lower posterior margin diagonally, the number of rows of lenses in normal, mature individuals is ten, in senile or in young individuals often eight or nine. The average number of lenses in nor- mal adults, ascertained by enumeration upon several hundred eyes, is between forty and fifty for each eye. The variation in the number of lenses, as far as observed, is between thirty and eighty-eight for each eye ; the former in a verj young individual, 12 mm. in length; the latter in an adult of average size, measuring 34 nun. in length, and hearing eleven rows of lenses. Eyes show- ing more than sixty-live and less than forty lenses are unusual. Thorax sub-quadrate, lateral margins slowly tapering. Surface strongly trilo- bate. Axis flattened at the margins, evenly convex in the middle, slightly nar- rower than either lateral lobe, widest at the third or fourth segment, tapering very slowly to the ninth, and thence much more rapidly to the pygidium. Pleura flat for about one-third their width from the axis and thence abruptly deflected to the margin. Each segment along the axis shows a slight retral bend from the margins to a point where, upon the under surface, the basal joints of the branchiae, natatory appendages, or visceral supports were attached. Each segment of the pleura1 bears a furrow which becomes obsolete at the fulcrum ; beyond this point the segment becomes attenuate, presenting scarcely more than a beveled surface of articulation. PrciDlUM relatively small; posterior margin the arc of a circle; anterior mar- gin transverse in the middle, angulated toward the sides by the articulating planes. Axis rapidly and evenly tapering from the last segment of the thorax, reaching an acute termination just within the posterior margin. Pleura broad, depressed-convex, sloping evenly to the posterior margin. In well-preserved examples, nine simple, transverse annulations can be counted upon the axis, and seven upon the pleura'; the latter being broadly 22 PALEONTOLOGY OF NEW YORK. rounded and simple. The doublure is broad, extending about one-fourth the distance across the shield, and slightly thickened at the margin. The out- line is truncate or slightly emarginate at the apex of the axis, a feature always exaggerated in flattened specimens. Ornamentation. In the average mature individual the surface of the test is ornamented with tubercles, which are largest and most closely set upon the glabella. Upon the cheeks, the axis and the pleural annulations of the pygidium, the tubercles are smaller and less distinct, and except in senile individuals, in which the entire surface is pustulose, certain portions of the tesl are comparatively smooth, namely, the palpebral lobes, the pleurae, the marginal portions of the axis and pygidium. Upon the doublure and epis- toma the surface is marked by sub-parallel lamellose lines. Ventral Anatomy. Ihjposloma. Notwithstanding the abundance of this species the hypostoma has rarely been observed. A well-preserved example belonging to a large individual, is elongate-triangular or sub-spatulate, very wide on the anterior margin and strongly auriculate, the antero-lateral extensions having a width equal to one-fourth the width of the plate. The width of the plate on the anterior margin is one-third greater than the axial length. The lateral margins are parallel for a short distance, thence approximating rapidly, and the posterior extremity bears three small spines, one situated in the axial line, and a shorter one on either side. The lateral margins and the antero-lateral processes are sharply indected. The centrum is large and broadly convex, bounded behind by a distinct sulcus, and showing indica- tions of two postero-lateral depressions. Low circular depressions are also noticeable near the antero-lateral angles. Surface covered with con- centric stria1. Carefully prepared sections of the test show, upon its inferior surface, a series of paired processes, which take their origin upon each segment of the axis, beginning with the third lobe of the glabella and extending to the pygi- dium. These processes are digitiform, hollow, flattened or faintly grooved CRUSTACEA. 23 on the posterior face, continuous with the test, and formed by the deep deflection of the anterior margin of each segmenl and its reflection to the articulating ring. They originate just within the mar-ins of the axis at points which are marked upon its dorsal surface by a slight posterior deflec- tion of the segments, and as they pass downward converge toward the axial line where members of the same pair would nearly meet. Thirteen pairs of these processes are discernible, one for the third lobe of the glabella, one for the occipital annulation, and eleven for the segments of tin- thorax, the first two lobes of the glabella and the annulations of the pygidium being unrepre- sented. Similar processes have been observed in Phacops latifrons by von Koenen (Neues Jahrb fur Min., etc., 1880, vol. i. p. 43U), and are regarded by him as the liases of support for the natatory appendages. The interpreta- tion of the ventral anatomy of the trilobites as given by Waleott for certain species {Cahjmene senaria, Ceraurus pleurcxanihemus), would regard such pro- cesses as enclosed within the "ventral membrane," and consider them functionally as supports for the axial viscera. Sections of other specimens of Phacops rana showr evidence of the existence of such a ventral membrane, to the lower surface of which the natatory appendages were probably attached. The presence of this membrane does not, however, preclude a direct muscu- lar connection across the visceral cavity, between the axial processes and the leer-bases. - Development. The members of this specie- assume very early in their life- history the essential features of maturity. Notwithstanding the abundant material in the collections of the State Museum, which afford gnat variations in size, no noteworthy deviation in form, proportions or details has been observed in the different stages of growth, except in the number of corneal lenses, as noticed above. Dimensions. An average of several hundred measurements gives for the average individual a length of 32 mm., and a width of 19 mm. Tin- largest entire individual observed measures as follows : i lephalon. Thorax. Pygidium 32 mm. 38 mm. 30 mm, 53 mm. 51 mm. 47 mm 24 PALEONTOLOGY OF NEW YORK. Body. Length LOO mm. \\ idth :>;J mm. The smallest entire specimen .seen is VI mm. lung and 6 mm. wide. Frag- ments of both linger and smaller individuals have been observed. lions. Specific Diagnosis. The original of Calymene bufo, Green (Mon- aph of the Trilobites of North America, p. 41), was an imperfect individual redited to an uncertain locality in the State of New Jersey, which may be re- led as of Devonian age. Calymene bufo, var. rana, Green (loc. tit.), is cited by the same author as occurring at Seneca, Ontario county, N. Y., which is a Locality on the shales of the Hamilton group, and as this Phacops is the only representative of the genus known to occur in this formation in the State of New York, no doubt can remain of the correctness of the specific reference. Phacops rana is very generally disseminated throughout the different horizons of tin; Hamilton group, from the Marcellus shales to the top of the Tully limestone. It may also occur in extremely rare instances in the Upper Helderberg limestones, but the species of Phacops so abundant in the latter formation and usually referred to Phacops ram/, has proved to be an entirely distinct form, Phacops crislntn, var. pipa. (see description of that species, where the differences in the Phacopes of the Hamilton and Upper Helderberg formations are summarized). Phacops rami finds closer allies in the Devonian species of Europe. With Phacops latifrons, Bronn, from the middle Devonian of theEifel and elsewhere, it is closely similar in general proportions and most of its superficial details, both species having the pleural annulations of the pygidium simple and the termination of the axis acute (a, noteworthy agreement). Points of difference may. however, he enumerated as follows: Phacops latifrons has (a) the cephalon more compressed laterally; (b) a narrower and more pentagonal glabella; (c) a more coarsely tuhcrcled glabella and smoother cheeks; (d) more numerous corneal lenses, varying between seventy-seven and ninety for average adult individuals; a variety of this species having as many as one hundred and twenty. CRUSTACEA. 25 A still more intimate agreement may be found in the form Phacops laHfrons, var. occitanus, Tromelin and Grasset, as described by Barrois (Ann. de la Soc Geol. du Nord, vol. xiii, p. 75, L885), from the lower middle Devonian of the Herault. This variety, with all the essential specific characters of Ph. latifn has the eyes less elevated, the basal glabellar annulation smaller and without' the strong, central tubercle; the tuberculatum of the glabella is liner, and the granules on the pleurae of the pygidium less strongly marked. These different forms undoubtedly represenl the same species in trans-oceanic faunas, and are only such variations as might be expected in descendants of the same ancestors subjected to different conditions of life. With Phacops fecund us, Bar- rande, of the later formations (Hercynian) of the Bohemian Basin, etages F, G and H, there is also a close agreement except in the occurrence of silicate annulations upon the pygidial pleura? in the latter species. The specimens from the Eureka District and Lone Mountain, Nevada, identi- fied by Walcott (foe. at.) as Phacops rana, Green, present points both of similarity and difference with the typical forms of the species, at the same time showing distinct features allying them to the Upper Helderberg species Phacops cristata. They resemble the former species in (a) the absence of spines at the genal angles, (b) the apparently simple pleural annulations of the pygidium; they are similar to the Upper Helderberg form in (a) the inconspicuous palpebrum, (b) the strong palpebral lobe, (c) the deep and broad occipital furrow which bears no trace of the transverse ring behind the frontal lobe, (d) the elevated and narrow occipital ring, (e) the hypostoma with strong antero-lateral eleva- tions enclosing shallow depressions, (f) the obtuse and flattened termination of the axis of the pygidium, (g) the interrupted terminal annulations of the axis. This western form, as observed by Mv. Walcott, thus appears to be a variety connecting the two species named and may eventually be regarded as of distind specific value. Distribution. Upper Helderberg group. The occurrence of Phacops rana in this formation is not yet establi>hed beyond question A single specimen is labelled from the Corniferous limestone near LeRoy, Genesee county. Hamil- ton group : In the Marcellus shales rarely, at Chapinville, Ontario county : in .26 PALAEONTOLOGY OF NEW YORK. the limestone near the top of these shales abundant, at LeRoy and Stafford, Genesee county ; Flint Creek, town of Seneca, Ontario county: in the Hamil- ton shales everywhere; the most prolific localities being in the western coun- ties; Tichenor's and Menteth's Points, Canandaigua Lake ; Centerfield, Hope- well and Flint 'reek. Ontario county; shores of Seneca and Cayuga Lakes; Moscow and York, Livingston county; Darien and Pavilion, Genesee count v ; Hamburgh and Eighteen-mile Creek, Erie county : in the Tully limestone at Moravia, Seneca county; Bellona, Yates county; near Borodino, Onondaga county. Also in the Hamilton formation at Charlestown, Indiana; " Bake- Oven," Jackson county, Illinois; Iowa City, Solon, Roberts' Ferry, Johnson county ; Independence, Buchanan county, and New Buffalo, Scott county, Iowa;* Washington Street Bridge and Whitefish Bay, near Milwaukee, Wisconsin; Cumberland, Maryland ; (?) Comb's Peak and Lone Mountain, Nevada; Wid- der and Arkona, Province of Ontario. Phacops bufo. PLATE VIII, FItiS. 25, J6. Cahjmtu< bufo, Green. Monogr. Trilob. North America, p. 41. 1832. Phacops bufo, Hall. Descr. New Species of Fossils, etc., p. 65. 1861. Phacops bufo. Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 03. 1862. Phacops bufo, Hall. Illustrations of Devonian Fossils, pi. viii, figs. 24, 25. 1876. The type specimen of Dr. Green's species is an imperfect cast of the lower surface, and is said to have been found in a dark grayish limestone in the State of New Jersey. Its geological horizon was not definitely stated by its author, but is undoubtedly of the age of the Upper Helderberg or Hamilton group. The original example of the species presents a general agreement with Phacops rana (Calymcne bufo, var. ram, Green), of the Hamilton group, but appears to be somewhat more elongate, with a proportionally longer and more tumid glabella. Specimens from New York State agreeing with the type have not been observed. localities in Iowa have beer kindly < municated by Professor Samuel Calvin. CRUSTACEA. 27 Phacops Cacapona. PLATE VIII, PIGS. 19 U. Calymene bufo, Castelnad. Essai sur le Syst. Sil. de ['Amir. s''pt , p. 21, pi, ii, figs. 1 I. 1843. Phacops Cacapona. Hall. Descr. New Species i f Fo ils, etc., p. 68. 1861. Phacops Cacapona, Hall. Fifl th Rept. N. V. State Cab. Nat. Hisl . p. 91 Phacops Cacapona, Hall. Illustrations of Devonian Fossils, pi. viii, figs. IS 23. 1876. The two specimens from which this species was originally described are inte- rior and somewhat imperfect casts of enrolled individuals, retaining very few ol the features which are essential in determining the value of closely allied species of this genus. In general proportions they resemble Phacops rami, as that fossil appears in the limestone layers of the Hamilton group, except that the glabella is more protuberant and the glabellar furrows more strongly marked, and in these features it approximates Phacops cristata. Whether the species belongs to either of these two, or is valid in itself, cannot be definitively determined without the ac- quisition of specimens retaining the test, the genal extremities and the pygidium. The specimens described and figured by Castelnau(/or.e//.)as ( 'alymene bufo, Green, were from the same locality as the type specimens of Phacops Cacapona. This author's figures do not, however, assist in determining the specific value of his examples. Distribution. Hamilton group. Mouth of the Cacapon River, near its junc- tion with the Potomac, Virginia. Phacops nupera. PLATE VIII, FIG. r,. Calymene nupera, Hall. Geology of N. Y. Survey Fourth Geol. Dist., p. 262, fig. 116. 1S43. Phacops nupera, Hall. Illustrations of Devonian Fossils, pi. viii, fig. 26. 187U. The type specimen of this species was found during the progress of the geo- logical survey of the State in a loose block of sandstone, apparently of the age of the Chemung sandstones, near the mouth of Chemung Creek, in Chemung county. No other specimen is known to have been found since, and this is not satisfactorily preserved for purposes of identification. In all apparent features it agrees with Phacops rana of the Hamilton group, but the critical characters for distinguishing the Devonian Phacopcs, viz. : the genal extremities, the cephalic doublure and the pygidium, are not retained, and it is consequently impossible to determine its specific value. The original designation is, therefore, retained, awaiting the acquisition of material which may serve either to establish or discard it. Distribution. Chemung group. Chemung Creek, Chemung county. 28 PALEONTOLOGY OF NEW YORK. DAL M A N ITES, Barrande. 1852. H A U S M A N N I A , n. s.-g. Dalmanites (Hausmannia) pleuroptvx. PLATE XI A, FIG. 1-3. Asaph \tyx, Greek. Monog. Trilob. North Amer., p. 55. 1832. IX, Hall. Pal. N". Y., vol. in, p. 356, pi. 74, figs. 5 1 9 ? (not figs. 1-4, 6-8, 10-12) ; pi. 75, fig. 1 1 1859. Tins species, the most abundant of all the trilobites of the Lower Helder- berg faunas, has been found in the Oriskany sandstone of Canada, associated with Spirifera arreda, Streptorhynchus (Ortkis) hipparionyx, Phacops cristata and Dalmanites anchiops, and also in two well-defined examples of the pygidium, in the Corniferous limestone of the State of New York. The species thus becomes the only member of the trilobitic fauna of the Lower Helderberg known to have continued its existence into the Upper Helderberg formations. Its occurrence in Devonian horizons affords the opportunity of suggesting some corrections of the previous identifications of the species The two species, I), pleuroptyx, Green, and J), micrurus, Green, both of which were established upon pygidia, were recognized in the third volume of the Palaeontology of New York, ami the differences between them were there pointed out. It is nevertheless true, that while it is not difficult to select examples of such pygidia as appear to he specifically distinct, the differences seem to disappear with abundant material, so that upon the basis of the pygidia alone, the attempt to separate the two species is exceedingly unsatisfaetory. The type specimen of D. pleuroptyx was from the Lower Helderberg of the Helderberg mountains, and extensive collections subsequently made from this prolific locality show that the abundanl pygidia of this species are every where associated with cephala heretofore undescribed, a specimen of which is here figured (pi. xi a, fig. 1). CRUSTACEA. 29 The outline of this cephalon is nearly crescentic, its length one-half its width, and the gen al angles produced into conspicuous spines. The glabella with that of D. Hausmanni, both in proportions and character of lobation. li> frontal lobe hears three circular depressions, one on the axial line and one near each of the lateral extremities; of these the former is largest and deepest. The eyes are large and elevated, the orbital sulcus unusually broad and con- spicuous; the cheeks slope abruptly in front, and more evenlj toward the genal angles, and their surface is marked by irregular, conspicuous wrinkles, except where it is crossed by the broad, smooth sulcus in which the facial suture lies. The border is a very characteristic feature, being moderately broad, smooth and concave on the sides, narrowing near the extremities of the frontal glabellar lobe and produced in front into a sub-nasute extension, .lust below the lateral extremities of the glabella begins a series of marginal crenulations or alternate thickenings and thinnings, which become more conspicuous anteriorly. The border thus has a character similar to that of /) anchiops, and is of especial interest as suggesting the inception of that peculiar frontal orna- mentation which is more fully developed in Odontocephaltts. There is no doubt that this is the cephalon of D. pleuroptyx, as in one well-defined example the parts have been found in conjunction. The cephala which were referred to this species on plate lxxiv of the third volume of the Palaeontology of New York, with the possible exception of figures 5 ami !•. must therefore belong to another species. No similar heads have been found in the Helderberg mount- ains. The original pygidium of D. micrurus, Green, is known to have come from Schoharie, although the author regarded it as from Trenton Falls. At Schoharie the large pygidia which agree with the type of D. micrurus are not uncommon, and the cephala with which they are there associated, and those in the western extension of the Lower Helderberg formation, in Herkimer county, should probably be regarded as belonging to this species. The cephala described here as that of D. pleuroptyx appear to he of rare occurrence at Schoharie, and that species seems to have been most abundant in the Shaly Limestone, and D. micrurus in the Lower Pentamerus Limestone. The entire young individual figured on plate lxxiv (Pal. N. V.. vol. iii). may 30 PALEONTOLOGY OF NEW YORK. be regarded as a specimen of the latter species. The fragmentary specimen represented on plate lxxv, fig. 1, is from a locality in Pennsylvania, and its coalesced glabellar lobes indicate a distinct species. Distribution. Lower Helderberg group. Near Clarksville, Albany county; Schoharie, Schoharie county. Oriskany sandstone: Township of Walpole, Province of Ontario. Corn iferous limestone : Clarence Hollow, Erie county; Lime Rock, Genesee county. Dalmanites (Hausmannia) concinnus. PLATE XI A, FIGS. 9-11. Dalmanites concinnus. Hall. Illustrations of Devonian Fossils, pi. x, figs. 3-5. 1876. Pygidium only known. Outline sub-triangular, posteriorly acuminate. Surface convex, trilobate. Axis relatively narrow, width less than one-third that of the shield, slightly elevated along the axial line, and tapering to an abrupt termination within the margin ; bearing nine to ten flattened transverse annotations, which are thickened or faintly nodose on the axial line. Pleura broad, deflected in an even curve to the margins and bearing seven or eight annulations which are broad, low and flat, and are separated by fine narrow sulci. The first five annulations are grooved by fine impressed lines, which extend to the margin. The anterior and posterior limbs thus formed are of equal strength. The margin is slightly thickened, becoming wider posteriorly and produced into a short and stout caudal spine. Surface smooth or minutely granulose. Dimensions. The largest pygidium observed has a length of 16 mm., and a width of 18 mm. ; the smallest a length of 9 mm., and a width of 10 mm. I H.stribution. Upper Helderberg group. Schoharie grit, Schoharie, Schoharie county ; near Clarksville, Albany county ; Corniferous limestone, near Caledonia, LivingstoD county; Cayuga, Province of Ontario. Dalmanites (Hausmannia) concinnus, var. serrula, n. var. PLATE XI A, FIG. 12. A single very small pygidium measuring 4 mm. in length and width bears all the characters of the normal pygidium, but has in addition to them a row CRUSTACEA. 31 of short spinules upon the lateral margins. These spinules are five in number upon each side, the first being the largest, their size diminishing posteriorly so that the last is little more than a crenulation of the margin. They are short, stout, acute, and directed backward. The terminal spine of the pygidium also is relatively longer and more slender than in the normal form. This specimen is from the decomposed chert of the Corniferous limestone at North Cayuga, Province of Ontario. DaLMANITKS (HaI SMAWIA) I'HACOl'TYX, 11. Sp. PLATE XI \. FIGS. - Fragments of three large pygidia show pleura' which are broad on the anterior margin, but narrow rapidly backward and are abruptly deflected toward the posterior extremity. The margin is entire and the border quite narrow, widening at the posterior extremity, where it is laterally flattened and pro- duced into a stout spine, having about one-fourth the length of the pygidium, and strongly bent upward. The axis is composed of eleven or twelve moderately broad annulations, and towards its posterior extremity merges into the caudal ridge and spine. The pleural bear twelve or thirteen ribs which are separated by wide, shal- low sulci, and are strongly curved backward near their distal extremities. Each of these annulations is conspicuously sulcate. The surface is covered with spinules and acute tubercles which appear to be irregularly scattered over the annulations. On the axis they are sometimes in pairs or in single transverse rows, becoming crowrded together near its margins; on the pleurae they appear to lie exclusively upon the anterior limb of each annulation, although the larger spinules are often so broad at the base as to extend across the entire width of the annulation. The surface between the tubercles and spinules is covered with fine granulations. Dimensions. The largest and most complete specimen observed has a length of 62 mm. to the tip of the caudal spine; its width across the anterior margin, when entire, would be about 85 mm. Observations. This species, though imperfectly known, is of interest as pre- senting a continuation into the Devonian formation, of a type of Dalmanites 32 PALAEONTOLOGY OF NEW YORK. which attains its highest development in the Silurian. In outline and contour it shows an intimate relationship with an undescribed species of Dalmanites from the Lower Helderberg formation. It is, moreover, directly comparable with Dalmanites spinifera, Barrande, from the etage G, and D. rhenanus, Kayser, from the Wissenbach slates of the Lower Devonian. Distribution. Upper Helderberg group. Cayuga, Province of Ontario. Dalmanites (Hausmannia) Meeki. PLATE XI A, FIGS. 28-30. Dalmanites (andet. sp.), Meek. Gteol. Expl. Fortieth Parallel, vol. iv, p. 48, pi. i, tigs. 11. 11a. 1877. lanites Meeki, W ili ott. Monogr. U. S. Geol. Suit., vol. viii : Pal. Eureka Dist., p. 207. pi. xvii, tigs. 5, 5a-h (not fi£. 5e). 1S84. The material representing this species consists of detached specimens of a glabella, a very large hypostoma and a quite perfect pygidium. The last- named part is very closely similar, probably identical with the pygidium of Dalmanites anchiops, but if the associated glabella belongs to the same species as the pygidium it will be necessary to regard these fragments as characteriz- ing a distinct specific form. Cephalon. The glabella is very similar to that of Dalmanites pleurophjx, Conrad. The frontal lobe is large and transversely sub-elliptical, depressed-convex above ; the three pairs of lateral lobes are distinctly defined; the first two widest at their outer extremities, the last narrow, transverse and extending as an annulation across the glabella. The lateral furrows of the second pair appear to he nearly obsolete toward their distal extremities, causing a tend- enc3 to coalescence in the adjoining lobes. The occipital furrow is narrow and shallow, the occipital ring moderately broad and elevated, and without any central spine. Pygidium as in Dalmanites anchiops, although bearing two or three more pleural annulations than is usual in mature examples of that species. Hypostoma elongate-triangular, surface depressed-covex. Anterior margin slightly arched, antero-lateral extremities sub-auriculate. Centrum broadly CRUSTACEA. 33 convex bearing a pair of short lateral furrows which terminate centralis in two conspicuous depressions or pits, bounded posterior^ by a low sulcus, beyond which is a linguiform extension bearing upon its margin five spinules, one of which lies on the axial line, with two on either side. Distribution. "Lower horizon of the Devonian limestone. Comb's Peak, and on the divide at the head of the Reese and I!err\ Cat Eureka District, Nevada.'1 (Walcott, he. cit.) •'<> l; ONUR A. n. s.-G. Dalmanites (Cokonura) aspectans. PLATE XII. FIGS. 1 11. 1.;. Asaphus aspectans, Conrad. Fifth Ann. Rept. Pal. N. *i .. y. 49, fig '.>. 1341. Asaphus? denticulatus, Conrad. Fifth Ann. Rept. Pal. N. ■> .. p. t8. 1841. Dalmania adspectans (in error). Hall. Deser New Species if Fossils, efc p.60. 1861. Dalmania Helena, Hall. Deser. New Species of Fossils, etc., p. 61. I Dalmania adspectans (in error), Hail. Fifteenth Rept. N. V State Cab Nat. Hist., p. 88. 1862. Dalmania Helena, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 89. IS62 Dalmanites Ohioensis, Meek. Pi Acail. Nat. Sci. Phil., p. 91. 1871. Dalmanites Ohioerisis, Meek. Pal. Ohio, vol. I. p. 234, pi. xxiii, fig. I. 1st:;. Dalmanites denticulatus, Hall. Illustrations of Devonian Fossils, pi. x, fis<-. I. 1876. Dalmanites aspectans, Hall. Illustrations of Devonian Fossils, pi. xiii, figs. 6 8. IS76. Dalmanites Helena, Hall. Illustrations of Devonian Fossils, pi. xiii. figs. II II. 1876. Tins species has been observed only in detached portions of the exoskeleton. The pygidia which have been described tinder the specific designations Dalmanites Helena and D Ohioensis (op. cit.), are not uncommon in the Corniferous limestone of New York and Ohio, and associated with them are fragments of large cephala, which presumptively can belong to no other species. Such a fragment of the cephalon, consisting of a free cheek retaining the visual surface of the eye. served as the original of the Asaphus aspectans of Conrad: more recently a larger fragment, also retaining the greater portion of the eye and agreeing in ail particulars with Mr. Conrad's type, has been found in the Corniferous limestone at Columbus, Ohio, associated with the pygidium of I). !/<:' There is no other ♦Through tin; kindness of Dr. .1. S. Newberry this specimen has 1 n made availabli Ebi use in the revision of these species. ;i PALEONTOLOGY OF NEW YORK. species known to us from this formation in Ohio, to which such fragments could be referred, and none in the Corniferous limestone of New York, except I), myrmecophorus, in which species the cephalon was undoubtedly similar in many respects to that of D. Helena, though of much larger dimen- sions than are indicated by these fragments. It seems necessary to establish Mr. Conrad's specific name, aspedans, upon a basis which will include the forms heretofore referred to D. Helena and D. Ohioensis. Tin' description of the original fragment is as follows: " A small portion of the buckler and one eye only is visible, but the eye is of an extraordinary height, the margins parallel, and the lenses arranged in parallel longitudinal lines, small and very numerous." In this specimen the eye is remarkably elevated, sub-semi-cylindrical, reaching a height of 9 mm., with a width of 8 mm. across the base. The corneal lenses are numerous, and though the condition of preservation does not permit the enumeration of them, thirty rows are visible, some of them containing as many as thirty-four lenses each. It would therefore be safe to infer that the eye bore not less than 700 lenses. The attached portion of the cheek has a broad flattened border, and is covered with strong, closely crowded tubercles. Additional details of the Cephalon are furnished by the Ohio specimen, as follows: the outline of the shield is semi-elliptical, the broad flat border slightly thickened toward its inner margin, the marginal sulcus deep and moderately broad, the genal angles produced into long sharp spines; the facial suture takes its origin at a point about half-way from the apex of the cheek-spine to the anterior extremity, passing abruptly forward over one- hall' the width of the border, thence straight across to the marginal sulcus, and inward to the inner angle of the visual surface; over the convex surface of the cheek it lies in a deep groove; the surface of the cheek beneath the e\ e is slightly flattened and the orbital ridge is well defined ; occipital furrow and ring moderately strong. Of the thorax nothing has been observed. CRUSTACEA. 35 Pygidium sub-ovate-triangular in outline, posteriorly truncate or broadly emar- ginate. Surface depressed-convex, with a general upward inflection poste- riorly. Margin thickened, narrow, widening into the post-axial border, Axis convex, width equal to one-fifth the width of the shield along a given annulation, regularly tapering to obsolescence upon the posterior margin ; composed of sixteen to twenty transverse, somewhat flattened annulations, separated by moderately strong furrows. Pleura wide, convex near the axis, thence regularly depressed toward the margin; composed of sixteen to eighteen broad, slightly flattened annula- tions, which become obsolete upon the margin. These are faintly sulcate, and are separated from one another by furrows, which are deepest and broadest near the margin. The border is ornamented by a fringe of conspic- uous spines, one in continuation of each pleural annulation. Of these spines the anterior pair is the shortest, and their length increases backward to the ninth or tenth pair, thence becoming shorter to the terminal pair, in which the spines are broader and stouter than elsewhere, and distinctly curved upward and toward the axial line. These terminal spines are separated, at their bases, by a distance equal to the width of the axis on its anterior margin The surface of the pygidium is covered with regularly arranged tubercles, of which the axis bears five longitudinal rows, one axial and four lateral (becoming two on the posterior annulations), each annulation bearing a single row of three or five tubercles Each pleural annulation bears two rows, one for each anterior and posterior limb. Upon the lateral margins the tubercles become stronger and are more scattered, while the posterior border between the terminal spines is smooth. In the New York specimens the entire surface ornamentation, with the exception of the marginal spines, is frequently almost or quite obsolete. Dimensions. An average pygidium from the Falls of the Ohio measures 60 mm. in length and 79 mm. in width ; one from western New York, 46 mm. in length and 67 mm. in width. The largest specimen observed has a length of 67 mm. and a width of 100 mm.; the smallest a length of 35 mm. and a width of 51 mm. 36 PALEONTOLOGY OF NEW YORK. ■ ions. The pygidium of this species, as already noticed, i.s subject to some variation in the matter of surface ornament. The type specimen of Bal- is, from the Corniferous limestone of the Falls of the Ohio, and all specimens from this locality have shown a. regularly tubercled surface. In the limestones of the same age near LeRoy, N. Y., where the species is abun- dantly represented, the ornamentation has become nearly obsolete, and it is probable that a specimen in such condition was the original of the Dalmanites Ohioi isis, described by Mr. Meek, from the Corniferous limestone of Marblehead, Ohio. In general form and outline, spinose margin and number of annula- tions, D. aspedans presents a close agreement with D. mijrmecophorus. There are however persistent differences in the two species which may be enumerated as follows: in I), aspedans the posterior border between the marginal spines bears no tubercles, and is only slightly elevated; the tubercles of the surface are not oodiform, and are always regularly arranged, except upon the lateral margins; the terminal spines are short and not laterally flattened. The original of Asaphus? denticulatus, Conrad (Fifth Ann. Rept. Pal. N. Y., p. 68. 1841), was a fragment of a pygidium reported as from the Schoharie grit, at Schoharie, and a specimen from the Upper Helderberg limestone at Schoharie, exhibiting the same characters as those accredited to Mr. Conrad's type, was figured in the Illustrations of Devonian Fossils (pi. x, fig. 1). The original of Mr. Conrad's description is no longer accessible, but the specimen mentioned from the limestone shows a variation from the type of Dalmanites Helena in having the posterior spines broader, stouter and more flattened vertically, the posterior border bearing a lew scattered tubercles; it retains, however, features characteristic of D. Helena (= aspedans) in the regular arrangement of the tubercles upon the aimulat ions, and the absence of an elevated spinose border. It seems advisable to include this slight variation under the species D. aspedans rather than to establish varietal terms for all intermediate forms between the closely allied species I), iisjieelans and I), mi/rmecophorus. The specific name ticulatus has actual priority by a single page over the term aspedans; as, how- ever, the fragmenl designated by the former name proves not to be in all respects a normal example of the species it represents, and as the description CRUSTACEA. 37 of the latter species was accompanied by a figure, no violence is dune to Mr Conrad's determinations by according recognition to the latter name. Distribution. Upper Helderberg group. Corniferous limestone: near Clarks- ville, Albany county ; Schoharie. Schoharie county ; Caledonia, Monroe count \ ; Lime Rock, near LeRoy, Genesee county; Clarence, Erie county; Falls of the Ohio, Columbus and Marblehead, Ohio. Dalmanites (Coiionura) myrmecophorus. PLATE XI A, FIG. 13; PLATE Mil, FIG. 12 ; PLATE XIV. FIGS. 1-6; \ni> PLATE XV, FIGS II. Asaphus myrmecophorus, GtKebn, Suppl. Monog. Trilob. North America, p. Hi. 1835. Asaphus.' acanihopleurus (acantholeurus, in error), Conbad. Fifth Ann. Rept. Pal. N. Y., \<. 48. 1841. DaJmniiiii mynnecophorus, Hall. Descr. New Species of Fossils, etc., p. HO. 1861. Dahnania myrmecophorus, Hall. Fifteenth Rept. N. V. State Cab. Nat. Hist., p. SS. 1862. Asaphus? acantholeurus, (Conrad) Hall. Fifteenth Rept. N. Y.StateCab. Nat. Hist., |>. 113. 1862, Dalmanites myrmecophorus) Hall. Illustrations of Devonian Fossils, pi. xiii, figs. 15, 16. 1876. Dalmanites acantholeurus, Hall. Illustrations of Devonian Fossils, pi. xix. fig. 14. 1876. The Cephalon and Thorax of this species have been observed only in a condi- tion so fragmentary as to be unsatisfactory for description or positive identification. Pygidium large, sub-ovate-triangular, broadly emarginate behind. Surface depressed-convex, scarcely flabellate, conspicuously trilobate. Posterior limbus with an upward curve, which begins at the posterior third of the shield and terminates in a vertical spiniferous border. Axis relatively narrow, width about one-fifth the width of the shield upon the anterior margin ; evenly tapering to a termination which becomes obso- lete within the posterior border. Composed of sixteen to nineteen broad transverse annulations, separated by narrow, deep furrows. Pleura broad, most convex at about one-third their width from the axial margins, thence rapidly sloping and becoming somewhat flattened near the edge; composed of fifteen to eighteen broad annulations, which widen toward their distal extremities, and in some instances show traces of a taint 38 PALEONTOLOGY OF NEW YORK. groove upon the surface. Bonier narrow at the sides, produced at the postero-lateral angles into two broad, stout, incurving cornua, whose inner bases are continuous and form an elevated marginal collar at the posterior extremity. The articulating ring and each pleural annulation, at its termina- tion upon the margin, bears a round, smooth terete, and gently incurved spine These spines are shortest in front and increase in length toward the posterior cornua. The posterior collar has a width equal to that of the axis on its anterior margin, ami hears a series of strong spines; one situated centrally, bifurcating at two-thirds its length, and, in a large individual, reaching a height of 10 mm., a short accessory pair of spines near the base of the foregoing (sometimes absent), a second ami stronger pair at the beginning of the posterior curve, a third pair at the base of the broad terminal spines, and the incurved, elevated terminal spines or cornua, each of which bears an accessory spine near the apex. (See plate xv, figs. 1-3.) The height of the cornua in a large example is 12 mm. The Surface of the pygidium is covered with strong, sub-spiniform, irregu- larly disposed nodes. Upon the axis each annulation bears but a single row, but no arrangement in longitudinal rows is discernible. Upon the pleurae there is evidence of an irregular, double row of nodes, but at the lateral and posterior margins the nodes are more abundant and irregularly disposed. A single example having an irregularly nodose axis, and a central spine on the posterior collar, has the pleural nodes relatively small, abundant and arranged in two regular rows as in Dalmanites aspectans, affording evidence of the affinity of these two species in this respect. The characteristic orna- mentation of Dalmanites myrmecophorus is however exhibited in pygidia varying widely in dimensions, the smallest individual noticed retaining this feature quite as strongly marked as the largest. A single large glabella which differs from that of any known species of the Upper Ilelderberg group, may belong to this species. It has the general outline and contour of the glabella in typical Dalmanites, except that there • an apparent tendency to obsolescence in the second lateral furrows. The frontal lobe hears a pair of conspicuous nodes just behind its center, and a CRUSTACEA. 39 pair of sharp tubercles in the median depression between the lateral lobes. The occipital furrow is narrow, and the occipital ring broad and rounded. The entire surface, except in the furrows, is sharply tubercled. Dimensions. An average pygidium measures 50 mm. in axial length and 80 mm. in width ; the largest observed is 1 15 nun. in length and ISO mm. in width; the smallest 6 mm in length and H) mm. in width. The glabella described has a length of 33 mm. and about an equal width. Observations. The remarkable size attained by the pygidia of Dalmanites myrmecophorus show it to have been, at maturity, an animal of gigantic propor- tions. A careful restoration of the outline of an individual on the basis of the largest pygidium above referred to, has been made by comparison with the proportions of other species of this type of Dalmanites, and the result, which may be regarded as approximately correct, at all events not exaggerating the size, indicates that the animal when entire may have attained a length of 398 mm. or 16 inches, the largest form of Dalmanites yet observed, and one of the largest trilobites known. A similar restoration of the smallest pygidium gives an individual 21 mm. or .8 of an inch in length. Fragments of large cephala and thoracic segments have been occasionally observed in association with these pygidia, but our present knowledge of these parts is insufficient for satisfactory description. A few thoracic segments found in place with a pygi- dium indicate an irregularly nodose surface, and fragments of the head-shield show a wide and Hat border, and a closely and strongly tubercled surface. The differences and similarities in Dalmanites myrmecophorus and Dalmanites aspectans are noticed under the description of the latter species. The Asaphus ? acantho- pleurus of Conrad (loc cit.) was described from a fragment of the posterior portion of a very large pygidium of this species, in which the central spine is very strong, and the other marginal spines, as indicated b) their bases, larger than have been observed in any other example. This specific term has been used in the various preliminary publications upon these fossils, as the nature of the posterior border in Dalmanites myrmecophorus had not at that time been observed. There now appears to be no doubt of the identity of the two species. The 10 PALEONTOLOGY OF NEW YORK. original of D. acanlhopleiirus is from "near Schoharie, in limestone with Odonto- cephalus (Onondaga limestone)." Distribution. Upper Helderberg group. In the Corniferous limestone, near Clarksville, Albany county; Schoharie, Schoharie county; Canandaigua, Ontario county; Lime Rock, near LeRoy, Genesee county. Dalmanites (Coronura?) emarginatus. PLATE XI A, FIGS. 7, 8. atus, Hall. Illustrations of Devonian Fossils, pi. x, fig. 2. 1876. < >f this species fragments of the pygidia only, have been observed, which may be characterized as follows; Outline sub-triangular, broadly emarginate behind; apex of reentrant angle sub-acute. A :■/:. narrow, tapering evenly to an apex near the posterior border and con- nected with the margin by a sharp, low ridge: it is composed of twenty to twenty-two transverse annulations. Pleura broad, slightly produced upon the posterolateral areas, and bearing seventeen to twenty broad and flattened annulations, which show a slight tendency to duplicature toward the posterior extremity. The border is narrow at the sides and widens a little posteriorly, where all the annulations become obsolete upon approaching it. Surface ornamented by pustules, each annulation bearing a single row upon the axis, and a double row upon the pleurae. The axis hears five longitudinal rows, one in the axial line, and two 'itherside. Upon the margin of the pygidium the pustules are more irregularly scattered. The lateral margins hear no spines and the posterior border is covered only with granulations. The dimensions of the shield are approximately 22 mm. in length, and 32 nun. in width. This little known species presents points of similarity with Dalmam ctans> bul differs in the following particulars, viz.: (a) the pos- gin is angulate and not transverse or crescentic, nor produced into CRUSTACEA 41 posterolateral spines, (b) the lateral margin is not spinose, (c) the termination of the axis is connected by an angular ridge with the margin. Distribution. Upper Helderberg group. Schoharie grit, Schoharie, Schoharie count v. [s.-g.] CRYPH.EUS, Green. 1837. Dalmanites (Cryph.eus) comis, n sp. PLATE XVI \, FIG. 1. A small and somewhat incomplete pygidium indicates an undescribed species of this sub-genus. It is characterized by the narrow axis curving slightly inward on the margins, and bearing six annulations, four distinct and elevated, and the last two faintly defined. The pleurae are moderately broad, sloping somewhat abruptly toward the margins, and bear five annulations, each of which terminates in a short, blunt spinule, with the apex directed backward. Whether or not there was a terminal spinule, as in the other American species, cannot be determined from this specimen. The pygidium has a length of 4 mm. and a width of 5 mm. Distribution. In the decomposed chert of the Corniferous limestone, Walpole, Province of Ontario. Dalmanites (Cryphjeus) Pleione. PLATE XVI A, FIG. J. Dalmania Pleione, Hall. Descr. New Species of Fossils, etc., p. 62. 1861. Dalmania Pleione, Hall. Fifteenth Rept. N. Y. State Cab Nat, Hist., p. 90. 1862. Dalmanites Pleione., Hall. Illustrations of Devonian Fossils, pi. xvi. tig. 17. 1876. CryphCBUs Pleione, Kav.-ek, Abhandl. z. Geol. Specialkavte von Preussen, etc . Band ii, Heft I. p 33. IsTs The imperfect pygidium which served as the original of this species is closely similar in general proportions, number of annulations and marginal spines to that of D. Booihi var. Calliteles. The spines however are relatively longer, more slen- der, rounder and more distant than in the mature individuals of the variety mentioned, but have a striking similarity to the pygidia of the young of that form. Our knowledge of the species in America is at present limited to the 12 PALAEONTOLOGY OF NEW YORK. single type specimen, but Kayser lias provisionally referred to this species a pygidium from the Lower Devonian at Daun in the Rhine-land. Distribution. Hamilton group. Hydraulic limestone, Falls of the Ohio. Dalmanites (Crypilfus) Bootiii. PLATE XVI, FIGS. 1-4; and PLATE XVI a, FIGS. 3-S. Cryph(Bus Bootl I, Green. Amer. Journ. Science, vol. xxxii, p. 343, figure. 1S37. Gry% -li'i, Conrad. Second Ann. Rept Palaeont. Dept. N. Y. State Geol. Surv., p. 66. 1839. Oryphasus a . < !onrad Second Ann. Rept. Palaeont. Dept. N. Y. State Geol. Surv., p. 62. 1862. Asaph . Conrad. Third Ann. Rept. Palaeont. Dept. N. Y. State Geol. Surv., p. 204. 1S40. Gryphon iteles, Hall Geology of N. Y., Pt. IV, p. 201. 1S43. [?] Cr Miteh s, De Verneuil. Bull. Soc. Geol. de France, 2nd Ser.. vol. vii, p. 164, pi. i, fig-. 3. 1850. is pectinatus, P. A. Roomer. Beitr. I. znr Kenntn. d. Harzgeb., p. 62, pi. ix, fig. 27. 1S50. Dahnania calliteles, Emmons. Manual of Geology, p. 138. f. 124(7). I860. Boothii, Hall. Descr. New Species of Fossils, etc., p. 63. 1861. \ania Boothii, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 91. 1862. Dalmanites Boothii, Hall. Illustrations of Devonian Fossils, pi. xvi, figs. 1-6, 9-11, 13, 15, 16. 1876. Gryphasus stellifei; Kayser (partim). Abhandl, z. Geolog, Specialkarte von Pr. und d. Thiir. St., vol.ii.pt. 4, p. 33. 1S7S. laciniatus, Kay.-kk (partim). Abhandl. z. Geolog. Specialkarte von Pr. und d. Thiir. St., vol. ii, pt. 4, p. 34. 1S78. General Form and Proportions. Body sub-ovate, laterally and posteriorly fimbriate; length about one-half greater than the width. Surface depressed- convex, distinctly trilobate. Axis prominent, elevated; pleurae flattened. CEPHALON relatively large; outline semi-elliptical, faintly produced on the frontal margin; length to width as 1 to 2. Frontal area narrow, lateral area broader but mostly occupied by the strong eye-lobes Margin thickened by a broad doublure, which widens under the frontal limbus to form the epistoma, and is produced at the genal angles into spines which normally reach to the sixth thoracic segment, and are equal in length to the axial length of the glabella. These spines are broad, thin and blunt, and lie nearly in a ver- tical plane. Tiie Facial Sutures take their origin on the lateral margins at points about balf-wav between the frontal extremity and the apices of the cheek-spines, pass inward and downward to the lower margin of the ocular lobe, thence over the eye to the anterior edge of the frontal lobe of the glabella, meeting near the anterior extremity just within the margin. CRUSTACEA. 43 Glabella elongate-sub-pentagonal; length and width equal, and nearly equal to the length of the cephalon. Frontal lobe large, transversely sub- elliptical in outline; the width equal to one-third that of the cephalon. The first pair of transverse furrows is long, directed obliquely backward; the second pair shorter and more transverse; the third pair still shorter and transverse. All these glabellar furrows are deeply impressed at their proximal extremities, as shown in easts of the inner surface. The first glabellar lobes are strong and sab-triangular; the second and third lobes shorter and more annular. Occipital furrow very narrow and sharply im- pressed ; occipital ring strongly arched upon the axis, narrowing behind the ocular nodes, and widening again to the genal spines. Eyes large, elevated, exceeding the height of the glabella. Visual surface lunate, corneal lenses numerous, an adult example showing fifteen rows, numbering diagonally from the lower posterior margin, and 206 lenses for each eye. Palpebrum inconspicuous, scarcely overlapping the visual surface. Palpebral lobe depressed, sloping evenly to the narrow palpebral sulcus. Thorax. Length to width as 1 to 1.5. Axis arched, widest at the fourth segment, tapering thence evenly to the pygidium. Pleura flattened, gently deflected along the fulcrum. Segments narrow upon the axis, with a slight double curvature, bending forward along the axial margins and axial line; grooved upon the pleura?, the anterior limb low and becoming obsolete along the fulcrum; the posterior limb slightly beveled, and considerably produced at the extremities. Pvgidium sub-triangular, depressed-convex. Axis tapering with slightly incurved margins, and ending abruptly just within the posterior border; bearing from ten to fourteen annulations in well-preserved specimens. The pleura eacli bear five annulations which are sulcate, the posterior limb in each becoming obsolete near the margin, while the anterior limbs are flattened, thickened, slightly curved and produced beyond the margin 1! PALEONTOLOGY OF NEW YORK. into spines having n length nearly equal to the length of the pleurae them- selves. A >|'iiic similar to these, but shorter and relatively broader, is pro- duced in the axial line, thus making eleven spines in the pygidial fimbria. Some slighl variation is noticeable in the form of these spines, but in typical examples, the ten lateral extensions of the fimbria are broad, short, flat and closely set, the apex pointed backward, the terminal lobe being shorter and linguiform. Bypostoma, elongate-sub-triangular; anterior angles auriculate, posterior ex- tremity sub-linguiform. Centrum convex, bounded posteriorly by a conspi- cuous sulcus. The postero-lateral pits on the centrum are joined by a faint groove. Surface covered with venate lines and faintly granulose. Surface Ornamentation. In the normal forms of this species the entire sur- face is covered with granulations which become quite strong on certain por- tions, viz., the axial region of the glabella, and thorax, and the surface of the pygidial fimbria, where the granules become elongate and pustuliform, often crowded and more conspicuous than upon the surface of the shield itself Upon the thoracic pleurae are single rows of low and inconspicuous pustules, which, in somewhat weathered specimens from the shales, often appear as shallow punctae. The occipital ring bears a strong central spiniform node, and the thoracic segments along the axial line, sometimes evenly rounded, are usually slightly angulated or nodose, the nodes becoming stronger toward the pygidium. The annulations of the pygidium are evenly rounded. The surface of the doublure is granulose. .->■ Variations from the type of Cryphaus Boothii, Green, as diagnosed by its author, and as here described more at length, occur in a series of asso- ciated forms presenting a marked and persistent deviation in certain features. This is most noticeable in the character of the pygidial fimbria, hut it appear.- that no variation has taken place in this feature without correlative variation in certain other respects. In many individuals of this sub-genus, particularly those occurring in the limestone layers in the Hamilton CRUSTACEA. 15 shales, the lobes of the pygidial fimbria, instead of being Bat, broad and contiguous, are more lanceolate, relatively narrow, elevated along the middle, with the apex nearly terminal. Upon careful comparison of these pygidia with Dr. Green's description of Cryphaus Calliteles, it appears beyond question that the species was founded upon a pygidium of this character. The original specimens of both C. Calliteles ami ('. Boothii were derived from the same locality, viz.: Huntingdon, Huntingdon county, Pennsylvania. The varietal feature of the pygidium with its associated characters is evidently a genetic difference, as it is apparent in the youngest individuals observed, and it therefore seems advisable to recognize in Green's species, C. Calliteles, at least a variety, with the following differential characters: Dalmanites (Cryph.-eus) Bootiu, var. Calliteles.* PLATE XVI, PIGS. 5-22; AND PLATE XVI a, FIGS, hit. Cryphu us Collitelus, Greek. A.mer. Journ. Science, vol. \xxii. p. 346. 1^;;7. Dalmanites Boothii, Hall. Illustrations of Devonian Fossils, pi. xvi, figs. 7,8, 12, 1 1. [S76. (?) Cryphu us calliteles, '. Kayser. Abhandl. /. Geolog. Specialkarte von Pi-, and d. Thlir. St.. vol. ii. part 4. p. 32, pi. iii. fig-. 10. 187S. Genal spines long, Hat, tapering to an acute extremity and reaching to the eighth thoracic segment; slightly depressed laterally and distinctly grooved by the occipital furrow for two-thirds their length. The occipital ring is unusually wide, and hears a stout spiniform node at its center. The first thoracic segment has a node or faint spine upon the axial line, and thence backward to the pygidium the spiniform nodes increase in size; the first annulation of the pygidium also bears a short spine. The lateral lobes of the pygidial fimbria are distant, narrow, lanceolate, elevated along the middle, having the apex terminal. The axial lobe is shorter than the rest, hut more elongate than in D. Boothi and acutely angled. The surface of the test is mostly very faintly granulose, the glabella and pygidial lobes generally quite smooth, the posterior portion of the genal spines more strongly granulose than any other part of the surface, and the thoracic segments furnished with single rows of low pustules. Abundant material representing this species affords evidence *The specific name of this species :is originally published is Collitelus, probably a typographical error for the personal noun Calliteles. 46 PALEONTOLOGY OF NEW YORK. of a considerable variation in size, from a length of 5 mm. to a length of L20 mm., as indicated by a large fragment, and this development in indi- vidual growth is accompanied, in the earlier stages, by considerable variation in the form of the pygidial lobes. A pygidium measuring 1 mm. in length ami 3 mm. in width to the tips of the spines, has a very elevated axis, which is sub-spinose along the axial line, strongly incurved toward the extremity, and hears hut six annulations. The marginal spines are unusually elongate and baccillate, the first pair being longest, the length decreasing backward, the two posterior pairs becoming strongly incurved toward the posterior extremity. The terminal lobe is very small and scarcely visible. With advancing growth the spines become relatively broader, and radiate regularly from the curve of the margin, assuming a sub-equal length, and the terminal lobe becomes gradually more conspicuous. Individuals occur occasionally in the shales of the Hamilton group, which indicate a slight inclination from the type of Dalmanites (C.) Boothi to that of the variety D. (C.) Calliteles to the extent of retaining the broad, short, vertically flattened cheek-spines of D. (C.) Boothi, and showing a tendency in the thoracic segments to become spinose on the axis, and in the pygidial spines to become narrow and acute. Such forms would naturally be expected in abundant material, but their rare occurrence, makes it inadvisable to recognize the usual variation as a dis- tinct specific form. Dimensions. A normal adult of Dalmanites (Cryphccus) Boothi affords the following measurements : Body. Cephalon. Thorax. Pygidium. Length 38 mm. 12 mm. 15 mm. 11mm. Width 24 mm. 24 mm. 22 mm. 18 mm. Of Dalmanites (Cri/phmus) Boothi, var. Calliteles, the following : Body. Cephalon. Thorax. Pygidium. Length 37 mm. 13 mm. 13 mm. 11mm. Width 26 mm. 26 mm. 19 mm. 21mm. CRUSTACEA. 47 Observations. It has been suggested ly Professor Emanuel Kayser (Fauna d. aeltst. Devon-Ablagerungen d. Harzes (he. tit.), p. 33), thai all the pygidia of Dalmanites Boothi represented in the Illustrations of Devonian Fossils {lor. tit.), do not belong to the same species, and he has consequently divided them in the following manner: Fig. 10 (pi. xvi), = Cryphoms stcllifer, Burmeister; figs. 8, 11, 14,= CryphcRus laciniatus, C. F. Roemer; tigs. 3, 6, 9, = Cryplueus Calli- teles (Boothii), Green. Our observations do not sustain this sub-division. The type of C. stellifer, Burmeister (Organiz. der Trilobiten, pi. iv. fig. 8), shows a terminal spine upon the pygidium, exceeding in length any of the marginal spines: the same is true of C. Calliteles? Kayser (loc. tit., pi. iii, fig. 10). This, however, is a feature which has not been observed in any specimen of the New York species. C. laciniatus, C. F. Rcemer, bears a distinctly triangular caudal shield and a very broad terminal lobe, while the C. laciniatus of the Sandbergers (Versteinerungen d. Rhein. Schicht. Syst., pi. i, fig. 5c), referred by Kayser to C. stellifer, Burmeister, differs in this feature, and if correctly figured, might with propriety be regarded as identical with C. Boothi, var. Calliteles. Distribution. Upper Helderberg group ] Dalmanites (Cryphcms) Boothi. The pygidia of this species have been observed in the limestone lying beneath the Marcellus shales at the Indian Reservation, four miles south of Buffalo, Erie county, associated with Chonetes lineata, Yanux., and Ch. laticosta, Hall. Hamil- ton group. Marcellus shales: In the limestone near the top of these shales, on Flint Creek, Ontario county ; LeRoy and Stafford, Genesee county. Hamilton shales: Rarely in the sandy shales of the eastern and central counties, at Bear's Gulf, near Summit, Schoharie county ; East Worcester, and elsewhere, Otsego county; Cazenovia and Madison, Madison county; Pratt's Falls and Delphi, Onondaga county; abundant in many localities in the western counties; on the shores of Seneca and Cayuga Lakes; in the shales above the Encrinal limestone at Menteth's and Tichenor's Points, on Canandaigua Lake, and in the towns of Hopewell, Gorham, Canandaigua and East Bloomfield, Ontario county; Pavi- lion and Darien, Genesee county ; Jaycox's Run, near Geneseo, and Moscow, Livingston county ; Eighteen-mile Creek and Hamburgh, Erie county. Also from Thunder Bay Run, Michigan. Dalmanites (Cryphaus) Boothi, var. Calliteles: 18 PALAEONTOLOGY OF NEW YORK. in the limestone near the base of the Hamilton shales, at Centerfield, and in the upper shales on Canandaigua hake, Ontario county. In the Tully limestone at Tinker's Falls, Onondaga county; Goodwin's, Cayuga Lake, and near Lodi Landing, Seneca hake. Dalmanites (Cryph.eus) Barrisi, n. sp. PLATE XVI \, FIG. IS. Sim.' [MENS of PYGroiA from the hull' and drab Devonian limestones in the State of Iowa, present certain peculiarities which will not permit their union with cither of the foregoing species. The general aspect of these caudal shields is quite similar to that presented by very young individuals of Dal- mani/rs Boothi, var. Calliteles, with the exception that in the latter the axial spine is scarcely developed, while in the Iowa species it is conspicuous and broader than any of the lateral spines. The lateral spines are long, round, .-lender and terete, with a gentle backward curve; slightly thickened at the base, and not elevated along the middle as in the New York species. They are also relatively much larger than in any adult specimen of the var- iety Calliteles observed. The axis of the pygidium tapers rapidly, and bears from six to eight annu- lations, which have a strong forward inclination in the middle. All the specimens representing this species are small, hut are of about the same -i/.e. and have undoubtedly attained their mature growth. The best preserved of the specimens has a length of 8 mm. to the extremity of the axial spine, a width of ',) mm. along the anterior margin to the bases of the lateral spines; the length of the anterior spines is 5 mm. Distribution. Hamilton group. In the limestones usually referred to this horizon near New Buffalo, and at Searstown and Iowa City, Iowa. CRUSTACEA. 49 [s.-g.J ODONTOCEPHALUS, Conrad. 1840. Dalmanites (Odontocephalcs) selenurus. PLATE XI B, FIGS. 15-21; and PLATE XII, FIGS. 1-13. Asaiikus selenurus, Eaton. Geological Text Book, p. 31, pi. i. tig. 1. 1832 Calymenef odontocephala, Green. Monog. Trilotrites of North America, Suppl., p. 9. 1832. Odontoeephalus selenurus, Conrad. Third Ann. Rept. Pala»ontological Dept. N. Y. Survey, p. 204. 1840 Odontocephalui selenurus, Vanuxem. Geology of N. Y., Survey Third Geol. Dist.. pp. 139, 140, tig. 1. 1842. Odontoeephalus selenurus, Hall. Geologj i f V Y., Survey Fourth Geol. Dist.. p. 175, tig. 1. 1S43. Dalmania selenurus, Hall. Twelfth Rept N ^ State Cab. Nat. Hist., p. 88. 1859. Dalmania selenurus, Hall. Descr. New Species of Fossils, etc., p. 56. 1861. Dalmania selenurus, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 84. 1862. Odontoeephalus ? {Dalmanites (Odontoeephalus) arenarius, Meek and Wortheh. Geol. Surv. Illinois, vol. iii, pp. 416, 417. pi. ix. fig. 10. Dalmanites selenurus, Hall. Illustrations of Devonian Fossils, pi. xii, figs. 12-14. 1S76. Dalmanites JEgeria, Hall. Illustrations of Devonian Fossils, pi. xii, tigs. 1, 2, 7. 1n7U. Dalmanites coronatus, Hall. Illustrations of Devonian Fossils, pi. xii, tigs. 15, 10. 1876. General Form and Proportions. Outline elliptical or elongate-sub-ovate ; anterior and posterior margins ornate. Length somewhat less than twice the width. Surface depressed-convex above, lateral slopes abrupt. Ceplfalon, thorax and pygidium to one another in length as 1 to 1.3 to 1. Cephalon. Outline sub-semielliptical, somewhat produced in front; length about one-half the width. Surface convex, sloping abruptly in front ami at the sides. Border moderately broad, horizontal in front and composed of nine conspicuous incisor-like processes, the strongest of which is central, writh four on either side, which become regularly smaller as the margin nar- rows backwards, the terminal one standing just in front of the lateral ex- tremities of the frontal lobe of the glabella. These tooth-like extensions are narrow and constricted at their bases, but widen rapidly so that they come in contact at the outer margin, though remaining entirely discrete. On the cheeks the border is broadly grooved and sloping, thickened along the outer and inner boundaries, and at the genal angles rounded or produced into a short, inconspicuous spinule. 50 PALEONTOLOGY OF NEW YORK. The facial sutures take their origin at points on the lateral margins about one-third the distance from the angles of the cheeks to the anterior extremity, ami are normal in their direction. Glabella sub-clavate or elongate sub-pentagonal, extending to the frontal margin. Length and width nearly equal. Longitudinal furrows deep. Anterior lobe sub-rhomboidal, wider than long. Surface gently and evenly convex, sloping somewhat more rapidly anteriorly than laterally. First lateral furrow." oblique and extending nearly across the glabella, second and third furrows transverse and short. First and second lateral lobes short and elevated, third lobes narrow anil annular. The axial portion of the glabella behind the anterior lobe is rounded and depressed. Occipital furrow narrow and moderately deep, becoming more conspicuous upon the cheeks ; occipital ring broad and elevated upon the axis, being very narrow upon the cheeks close to the axial furrows, but rapidly widening toward the genal extremities. Cheeks moderately broad, flattened and strongly sulcate about the base of the eyes; abruptly deflected laterally. Eyes prominent, elevated above any other portion of the head. Visual surface broad, lunate ; lenses numerous. Palpebrum not prominent; palpebral lobe very depressed. Thorax sub-quadrate, somewhat wider than long. Surface depressed-convex, deflected at the sides. Axis narrow anteriorly, widening to the sixth segment, thence backward rounding and tapering rapidly to the pygidium. The segments are broad and flat or gently convex, with an anterior curve over the axial line. Pleura moderately broad, flat along the axial furrows for more than one- hall' their width, theme deflected more or less abruptly. Each annulation is conspicuously sulcate, the anterior limb being as broad at the fulcrum as the posterior limb at its widest point. Pygtdium. General outline sub-triangular or sub-semielliptical. Surface depressed above, lateral slopes more or less abrupt. Border narrow; post- axial area Hat. bending slightly upward and bearing two slender divergent CRUSTACEA. 51 spines, giving the crescentic caudal extremity from which the specific name is derived. Axis relatively narrow, having less than one-fourth the width of the shield on the anterior margin; margins approximating with a slight inward curve to the apex which is broad, smooth, somewhat elevated, and distant from the posterior margin. Annulations from nine to eleven with indications of others on the terminal portion, visible only on casts of the under surface Pleura composed of eight flattened annulations and traces of a, ninth, which are abruptly bent backward near the margin. When the crust is well-pre- served the surface of each annulation bears a fine impressed line extending its whole length. Hypostoma elongate-sub-triangular or sub-linguiform. Anterior margin arcuate, antero-lateral angles auriculate. Centrum moderately convex, hearing posteriorly two pits connected by a faint groove, and separated from the posterior lingua by a conspicuous sulcus. The posterior margin appears to be smooth, but probably bears normally, one, three or five spinules. Lateral margins abruptly deflected dorsally. Surface Ornamentation. The surface of the glabella, cheeks, margin and mar- ginal denticulations is covered with faint obsolescent tuberculations. The entire test is very strongly punctate ami the openings of the vertical tubules are visible everywhere upon the upper surface as well as upon casts of the under surface. Dimensions. Fragments of this species show a wide variation in size. Entire individuals are however of comparatively rare occurrence, and of these one of average size measures as follows : Body. Cephalon. Thorax. Pygidium. Length 80 mm. 24 mm. 36 mm. 20 mm. Width 46 mm. 46 mm. 44 mm. 37 mm. The largest entire individual observed has a length of 95 mm., and the smallest a length of 50 mm. 52 PALEONTOLOGY OF NEW YORK. Observations. This species was originally described by Professor Amos Eaton, from a caudal shield bearing elongate, divergent spines, giving the posterior margin a crescentiform outline; and at the time of publication this was the only part of the animal known. The original of Culymene? odontocephala, Green, was a detached head, and was regarded as a distinct species until Mr. Conrad, in IS 1(1. described an entire individual from the limestone at Auburn, Cayuga county, under the name of Odontocephalus selenurus (Inc. at.). The species is abundant in many outcrops of the Corniferous limestone, and appears to be restricted to this formation. Entire individuals are, however, seldom met with unless in an enrolled condition. Although very closely allied in general features and in many details, with the associated species here referred to the same sub-generic group, Dalmanites selenurus is distinguished by the follow- ing persistent features: (a) the denticulations on the frontal margin number nine; (b) the extremities of the cheeks are obtuse or produced into minute spines; (c) the caudal spines are long, slender, divergent and bent upward, with their bases distant : (d) the number of pleural annulations on the pygidium is eight, with indications of a ninth. The peculiar frontal ornamentation in the species of Odontocephalus appears to have bad its inception in the marginal crenulations or thickenings on the frontal limb of Dalmanites pleuroptyx of the Lower Helderberg, a feature reproduced in the species D. anchiops of the Scho- harie grit. In both these species the crenulations are longest and most con- spicuous in front ami disappear opposite the lateral extremities of the anterior lobe of the glabella. In like manner, in the sub-genus Corycephalus, the Lower Helderberg species I), dentatus seems to be the forerunner of D. regalis of the Schoharie grit, and D. pygmmis of the Corniferous limestone, in all of which the dentate ornamentation extends around the entire cephalic margin. Distribution. Upper Helderberg group. Corniferous limestone: Marbletown, Qlster county; near Clarksville, Albany county; Schoharie, Schoharie county; Eastman's and other quarries, Waterville, Oneida, county ; Cherry Valley, Otsego county; Manlius, Onondaga county; Auburn, Cayuga county; Canandaigua, Clifton Springs and Phelps, Ontario county; Lime Rock, near LeRoy, Genesee county ; Clarence, Erie county. CRUSTACEA. 53 Dalmanites (Odontocephalus) B1FIDUS. PLATE XI B, FIGS. -'-' 25. Dalmania bifida. Hall. Descr. New Species of Fossils, etc . p. 63. 1861. Dalmania bifida. Hall, Fifteenth Repl N. "5 State Cab. Nat. Hist., p. 91. LS62. ( lompare Dalmanites (0 lontoeephalus) . Egeria, Hall ?, Meek and Worthen. i reology of Illinois, vol. iii. p 117. pi. x. fig. I a, b, c. 1S68. The i'YgidiuiM only of this species is known, and while presenting in general features a similarity with that of Dalmanites selenurus it is characterized by the following persistent points of difference, viz.: (a) the axis bears eight ambula- tions; (b) the pleurae show seven annulations with indications of an eighth; (c) the caudal extremity is narrow and considerably produced, making the post- axial area very conspicuous; (d) the caudal spines are close together, short, stout and parallel. The Dalmanites JEgeria? of Meek and Worthen (loc. cit.) appears to be more closely allied in the character of the terminal spines of the pygidium, to D. bifidus. The cephalon which is referred by these authors to the same species as the pygidia, is represented in their figure as having a frontal border with a row of elongate perforations which do not extend to the margin. If this character of the specimen is accurately shown, there can be no doubt that this form is widely different from any species of Odontocephalus known from formations in the State of New York. Distribution. Upper Helderberg group. Corniferous limestone : Phelps, Ontario county ; Lime Rock, Genesee county ; Columbus, Ohio. Dalmanites (Odontocephalus) yEgeria. PLATE XI H, FIGS 1-11. Dalmania JEgeria, Hall. Descr. New Species of Fossils, etc., p. 57. 1861. Dalinania ZEgeria, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist, p 85. 1862. Dalmanites 33geria, Hall. Illustrations of Devonian Fossils, pl. xii, figs. 3-6, 8-11. 1876. Tins species in its general features and broader details is so closely similar to D. selenurus, that the description of that species will serve for this one except in the following particulars: in D. Mgeria (a) the body is rather more slender, tapering more rapidly backward : (b) the frontal dentieulations are eleven in number, one central and five on either side, the terminal ones standing opposite the lateral extremities of the frontal lobe of the glabella; (c) the genal angles are .,1 PALEONTOLOGY OF NEW YORK. produced into slender spines which extend as far as the fourth or fifth thoracic seg- ment ; (d) the axis of the pygidium bears ten distinct annulations, and upon the cast of the under surface indications of five more; (e) the pleurae of the pygidium each bear ten annulations, the last of which is often indistinct; (f) the caudal extremity is furnished with two short, obtuse, depressed, sub- spiniform processes: (g) the surface of the pygidium, in well-preserved examples, hears a double axial row of tubercles, with a fainter row on either side, and scattered tubercles of the same strength over the pleurae. These characters appear to be persistent and indicate a well-defined specific variation from the type of Dalmanites selenurus. Distribution. The range of this species appears to be restricted to the out- crops of the Upper Helderberg limestone in the western counties of the State, where I), selenurus is apparently of rare occurrence, viz., Schultz's Farm, near Clarence, and Williamsville, Erie county. Dalmanites (Odontocephalus ?) coronatus. PLATE XI B, FIGS. 1-2-14. Dalmania coronata, Hall. Descr. New Species of Fossils, etc., p. 58. 1861. nata, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 86. 1S62. Dahnanites coronatus, Hall. Illustrations of Devonian Fossils, pi. xii, tig-. 17. ISTtJ. A single example of this species has been observed, and this consists of the pygidium and a portion of the thorax, both of which are closely similar to the corresponding parts in Dalmanites selenurus, the pygidia of the two species having the same cumber of axial and pleural annulations. The single specimen how- ever has a caudal extremity free of spines but broadly emarginate, evenly rounded and bent slightly upward. There is no evidence that spines have ever existeii and have been accidentally lost during the life of the animal, but the posterior margin appears to have been preserved in a normal condition. If this varietal feature prove, upon more complete knowledge, to be accompanied by a variation in the details of the head from that of D. selenurus, the species "ill afford an interesting initial form for the differences exhibited in the caudal spines of the several species of the sub-genus Odontocephalus. Distribution. Upper Helderberg group. Corniferous limestone: near Auburn, (\i\ uga county. CRUSTACEA. 55 CO 11 V CEPHAL LIS. v s.-g. Dalmanites (Corycephalus) regalis. PLATE XI, FIGS. 1 1. Dalmanites regalis, Hail. Illustrations of Devonian Fossils, pi. xi. IS76. Cephalon large, outline lunate or semi-ovate; length (axial) to width as 1 to 2. Border narrow and vertical in front, becoming broader on the sides, and produced at the genal angles into long incurving -pirns, which equal in length the axial length of the shield. The margin is ornamented by a series of quadrate denticulate processes, which are short in front of the glabella, but become broader ami longer on the sides. These processes are somewhat constricted toward their liases, hollow and sub-cylindrical in front, flattened at the sides. On the anterior margin they slope outward with about the same inclination as the frontal area, but at the sides they stand almost at right angles with the nearly vertical genal area, Nineteen of these processes are visible upon one-half of the most perfect example, a portion of those on the other half being broken away; this would make thirty-eight around the entire margin of the head. Facial Sutures apparently normal, lying in deep sulci in their course over the cheeks. Glabella sub-hexagonal; surface convex in front, depressed behind; widest across the tips of the first pair of lobes; length and width about equal. Anterior lobe large, sub-pentagonal, transverse on the anterior margin ; lateral margins short and nearly parallel to the axis: postero-lateral margins rapidly approximating. Surface convex, sloping almost vertically to the anterior margin, more gently to the sides, and is nearly horizontal posteriorly. The first lateral furrows are broad and shallow, inclined backward: the first lateral lobes are elevated and nearly transverse; the second lateral fur- rows are distinctly impressed at their inner extremities, becoming obsoles- cent outward, giving the first and second lobes the appearance of coalescing for the outer one-third of their length ; third lateral furrows narrow and 56 PALAEONTOLOGY OF NEW YORK. deep; third lateral lobes well-defined, transverse. Occipital furrow narrow, becoming wide and deep upon the cheeks; occipital ring very wide upon the axial line, but narrowing to the axial Furrows and upon the cheeks. Cheeks elevated, very convex and protuberant at the sides, constricted at their bases by the broad marginal sulcus; posterior slope abrupt. The summit about the base of the eye is grooved by a deep orbital sulcus. Eyes lunate elevated, moderately large; palpebrum depressed; lenses abundant. Thorax and Pygidium unknown. Surface covered with conspicuous, often sharp, spiniform tubercles, of which the strongest appear to be one in each angle of the occipital ring and marginal sulcus, and a single row about the bases of the marginal denticula- tions. Upon these processes the ornamentation consists of fine granules. Dimensions. The more perfect example of the cepbalon has an axial length of 45 mm.; a length to the extremity of the cheek spines of 92 mm., and a width of 88 mm. Observations. All that is known of this remarkable species is from the two somewhat fragmentary cephala which were collected in the year 1832. One of these is a cast of the dorsal surface and the other preserves nearly the whole of the crust. In the peculiar denticulate character of the border, distinct from that in the sub-genus Odontocephalus, the species finds an ally in the minute Dahnanites pygmmis of the Corniferous limestone. Distribution. Upper Helderberg group. Schoharie grit, in the town of Knox, Albany county. DALMANITES (CORYCEPHAL0S) PYGJ.LEUS, 11. Sp. PLATE XI. FIGS. 5-8. CephalON minute, outline sub-semicircular or sub-elliptical. Surface convex, abruptly depressed at the sides. Margin narrow, thickened and produced at the genal angles into long slender spines which curve inward toward the extremity. CRUSTACEA. 57 The facial sutures take their origin at points on the margins nearly one- half the distance from the genal angle to the anterior border, and follow a direction normal tor the genus. Glabella convex, scarcely elevated along the axial line. Width on the frontal lobe about one-third that of the cephalon, rapidly diminishing to the occipital ring. Frontal lobe transverse, sub-rhomboidal ; firsl glabellar fur- rows extending backward, each somewhat less in length than one-third the width of the glabella; second and third furrows transverse, short, not encroach- ing upon the mesial elevation of the glabella; first pair of glabellar lobes sub-triangular, second and third pairs smaller, sub-quadrate. Occipital furrow shallow, widening on the cheeks, and uniting at the genal angles with the marginal sulcus. Occipital ring conspicuous. Cheeks depressed at the margin, elevated toward the ocular lobes. Eyes anterior, elevated and relatively large. Surface finely pustulose except upon the border and occipital ring. The lateral margins and genal spines bear a series of denticulations or short spinules, which, in one specimen, appear to exist also upon the anterior border. The occipital ring bears a strong central tubercle. Dimensions. The two specimens of this species which have been observed have about the same size, namely : Length 1.7 mm. Length to apex of spines 3 mm. Width 2.5 mm. Observations. This little species bears a striking resemblance in its propor- tions and outline, incurved cheek spines and denticulated bolder to Dalmanites regalis of the Schoharie grit; in the former, however, the eyes are placed further forward, the glabellar lobes are relatively much smaller and the marginal denticulations narrower and pointed. The minute size of the specimens may indicate that they are the young of some species of whose mature form we are still ignorant, but as the only examples yet seen have the same size, it is probable they are of mature growth. 58 PALEONTOLOGY OF NEW YORK. Distribution. Upper Helderberg group. Corniferous limestone; in the decom- posed chert boulders, Canandaigua, Ontario county. Dalmanites (Corycephalus) dentatus. PLATE XI a. FIGS. 4-0. Dul inniiii.. < to Bakri i r. Amei'. .Tour. Science, vol. xi, 3d Ser., p. 200, plate. 1876. Dalmanitex dentata, Barrett. Amer. J •. Science, vol. xii. 3d Ser., p. 70. 187B. Tins interesting Lower Helderberg species is the earliest known form of Dal- manites which presents a development of the ornamentation of the frontal border of the cephalon, a feature which becomes so characteristic of many species of tli is genus in the Upper Helderberg. This ornamentation consists of a single row of acute denticulations, about thirty-five in number, decreasing in size toward the genal extremities, and in their shape indicating the inception of the broader, incisor-like processes of Dalmanites regalis, D. pygmaus and the group represented by D. selenurus. In other respects however Dalmanites dentatus retains the distinctive characters of the Silurian representatives of this genus, that is, forms following the type of Dalmanites Hausmanni, Brongniart, and in respect to features, which are not of an ornamental character, is in harmony w ith its associates in the Lower Helderberg formations, viz., D. nasutus, D. tridens, I), pleuroptyx. The distinct lobation of the glabella, and the absence of any tendency in the first and second lateral lobes to coalesce, the frontal glabellar depression, the long, terete thoracic segments, and the narrow, triangular, cau- date pygidium, are all features, which in their entirety, give a pre-Devonian aspeel to the species. With the opening of the Devonian age some or all of these features appear with modifications so distinct as to require the recogni- tion of sub-divisions in the genus. A notice of Dalmanites dentatus is introduced in this place for purposes of comparison with the Upper Helderberg species, and on account of its frontal ornament is referred with D. regalis and D. pygmeus to the group, Corycephalus. Distribution. Lower Helderberg -roup. In the shaly limestone at Port Jer- vis. Orange county; Becraft's Mountain, near Hudson, Columbia county. CRUSTACEA. 59 [s.-g.] CHASMOPS, McCoy. IS in. Dalmanites (Chasmops) anchiops. PLATE IX, PIGS. 1-6, 10, 12, 13; IND PLATE X, FIGS. 1-U. Calymene anchiops, Green. Monog. Trilob. North Amer., p. 35. 1832. Asaph ns laticostatus. Green. Monog-. Trilob. North imer., p. 4o. lSL^. Phacops anchiops, Bdrmeister. Organ, d. Trilob.. p. 90. L846. Dal mania anchiops, Hall. Descr. New Species of Fossils, etc., p. 55. 1861. Dalmania anchiops. Hall. Fifteenth Rept. N. Y. Stat.- Cab Nat. Hist., p. 83. 1862. Dul manites anchiops, Hall. Illustrations of Devonian Fossils, pi. ix, tigs. ], 3-6, 10, 12, 13 ; pi. x, figs. 6-14. 1876. General Form and Proportions. Body sub-elliptical in outline, more or less produced at the extremities. Surface depressed-convex, distinctly trilobate ; lateral margins deflected and sub-parallel. Length (including caudal spine), to width as 2 to 1. Cephalon relatively short, length about one-third the width ; outline crescentic, slightly produced on the frontal margin. Surface evenly convex. Border narrow anteriorly, bearing in front of the glabella five to seven low crenula- tions or undulations, which become wider and thicker upon the cheeks, and produced at the genal angles into stout and rapidly tapering spines, which reach the third thoracic segment. Doublure wide and deep at the genal angles, narrowing at the lateral margins, and extending into a relatively narrow epistoma in front. Facial Sutures normal. Glabella elongate sub-pentagonal, widest anteriorly, depressed-convex ; bounded on all sides by low sulci. Anterior lobe large, sub-rhomboidal ; first pair of lateral furrows long, inclined backward ; second pair obso- lete, except at their proximal extremities, where they appear upon the cast as two deep pits; third pair transverse or inclined slightly forward, almost obsolete at their distal extremities; first and second glabellar lobes coalescent, forming a single pair of large convex lobes, whose elevation exceeds that of the frontal lobe; third glabellar lobes narrow, depressed and relatively inconspicuous. Occipital furrow narrow on the axis, becoming 60 PALEONTOLOGY OF NEW YORK. broader and deeper on the cheeks, occipital ring prominent and bearing short and sharp central spine; narrowing to the axial furrows, thence rapidly u idening to the genal spines. Eyes lunate, large and elevated considerably above the summit of the glabella, and closely appressed against its coalescent first and second lobes. Visual surface with numerous corneal lenses, the single specimen (a young individual) in which they may be enumerated, showing eighteen rows, counting diagonally from the lower posterior margin, and one hundred and ninety-two lenses. Palpebrum scarcely prominent; palpebral lobe depressed and sloping abruptly to the narrow and elevated palpebral furrow. ( 'hecks sloping abruptly from the ocular node to the thickened and some- what flattened margin. A deep sinus, which is stronger in old individuals, hounds the ocular node and flattens the subjacent portion of the cheek. Thorax sub-rectangular, length to width as 4 to 5. Surface depressed-convex. Axis relatively narrow, widest at about the fifth segment, thence regularly tapering to the pygidium. Pleura relatively broad, Hat for about one-half their width and thence rounded to the lateral margins. Each segment lias a slight forward curve along the axial line, being sulcate on the pleura' and having the anterior limb abbreviated by the beveled planes of articulation. Pygidium sub-triangular, depressed-convex or flattened. Posterior extremity produced into a stout, upwardly curved spine, usually short, but sometimes equaling the pygidium in length. Length, including the caudal spine, equal to the width. Axis having less than one-third the width of the shield on the anterior extremity, regularly tapering to an obtuse, broadly rounded termination, and composed of from nine to fourteen broad, Hat, transverse annulations. Pleura broad and rounding more or less abruptly to the margins, bearing ,|-llt '"' lllm' wide, flattened annulations, which become obsolete just within the border. Wherever the crust is retained the annulations are seen to be CRUSTACEA. 61 faintly grooved near their distal extremities, but in the usual condition of preservation as casts of the lower surface, the tendency to duplicature is not often apparent. Doublure narrow on the sides, rapidly widening toward the posterior spine, where it extends forward as far as the termination of the axis. The caudal spine is not infrequently broken away from the margin of the doublure, giving the caudal shield a semicircular outline. Surface Ornamentation. The surface of the cephalon. within the border and the occipital ring, is covered by strong tubercles, which are closely disposed over the cheeks and more scattered on the glabella. In old individuals these tubercles extend to the margin, and the orbital ridge of the cheek becomes covered with hue granulations. The surface of the thorax and pygidium is smooth or finely granulose. Pygidia of young individuals show low nodes or tubercles upon the pleura?, apparently arranged in three or four oblique rows with indications of similar ornamentation upon the axis. Dimensions. The only specimen observed which retains the parts in con- junction affords the following dimensions, proper allowance being made for the caudal spine which is lost. Body. Cephalon. I rax. Pygidium. Length 103 mm. 25 mm. 40 mm. 38 mm. Width 49 mm. 49 mm. 50 mm. 39 mm. The smallest head-shield observed has a length of '.I mm., and a width of 16 mm., and the largest, which can safely be referred to the normal form of the species, a length of 35 mm., and a width of 70 mm. Pygidia vary in size from a length and width of 15 mm., to a length and width of 1 111 mm. Variations. Large cephalic shields associated with Dalmanites anchtops and bearing all the essential specific features of the normal form, afford some important varietal differences. One series of these variations has been already described under the first of the following designations. 62 PALAEONTOLOGY OF NEW YORK. Dalmanites (Chasmops) anchiops, var. abmatus. PL \TK IX, FIGS. 7-9. Pita, .11 m.i,. Foster and Whitney's Geol. Rept. Lake Superior, p. 124. 1S51. kiops, var. armata, Hall. Descr. New Species of Fossils, etc., p. 56. 1861. Da i, var. armata, Hall. Fil't th Rept. N. Y. Stati> Cab. Nat. Hist., p. 84. 1S62. Dili: . hiops, var armata, II ILL. Illustrations of Devonian Fossils, pi. ix, figs. 2, 7, S. 1S76. The points of variation iii these specimens may be thus summarized: (a) the spine upon the occipital ring is very long, round and very stout toward the base. Its length is sometimes quite equal to the length of the glabella, while in the typical forms of the species the spine is not more than one-third or one-fourth of that length; (b) the genal spines are inconspicuous or obsolete; (c) the surface, as shown in casts of the exterior, is free from tubercles or other ornamentation; (d) the eyes appear to be less elevated and bear fewer corneal lenses. As the cephala of this character have not been found in conjunction with the other parts of the animal, it is impossible to determine whether the thoraces and pygidia belonging thereto, also varied from the type, since none of these parts have been seen which show any variation from the normal form. The largest cephalon observed has a length of 80 mm., and a width of 116 mm., indicating an animal upwards of '2(H) mm. in length when entire. Dalmanites anchiops, var. sobrinus, n. var. PLATE IX, FIG. 11. Dalmanites, n. sp. ? Hall. Illustrations of Devonian Fossils, pi. ix, fig. 11. 1876. A single cephalon from the Schoharie grit has the general proportions of the speeies, |,ut shows a variation from the foregoing in the following particulars, viz.: (a) the glabella is much more convex, and projects slightly beyond the frontal margin, (b) the genal angles appear to be without spines, (c) the occipital ring bears no spine, (d) the facial suture, where it crosses the sum- mit of the cheek, lies in a much deeper sulcus. The original is a cast of the lower surface and is somewhat imperfect, but its features seem to be dis- tinctly varietal. CRUSTACEA. 63 Observations. The Calymene macrophtalma of Brongniart (Crustaa s Fossiles, p. 15, pi. i, figs. 4, 5. 1822) embraced much heterogeneous material, ami included a specimen which is now referred to Dalmanites anchiops. Two of the diverse forms mentioned by Brongniarl were from unknown localities in America; one of these was a plaster cast made from the specimen which subsequently served as the type of Asaphus laticostatus of Green. Of the others, one form {lab. cil., fig. 5), is the Calymene macrophthalma of Murchison, Phacops Brongniartii of Port- lock, and the Pharops latifrons of Burmeister; the other is the Phacops macrophthal- mus of Burmeister. The Asaphus Welherelli, Green, which lias Keen regarded by Burmeister (Organiz. der Trilob., p. 90) as probably a young individual of Phacops anchiops, was undoubtedly an imperfect specimen of Dalmanites limuhrrus, Green, from the Niagara group. Dalmanites anchiops and its varieties show a divergence from typical forms of the genus Dalmanites (D. Hausmanni, D. pleuroptyx, etc.), in the coalescence of the first and second pairs of tin' glabellar lobes, a feature which places it under the group Chasmops of McCoy. In the typical species of Chasmops (Phacops) conicophthalmus, Sars and Boeck; Phacops macrurus, Sjogren, these united lobes are large, and upon the dorsal surface give no apparent evidence of the obso- lescent second glabellar furrows. D. anchiops in its usual condition of preser- vation as casts of the inner surface of the test, shows traces of these furrows, hut when the crust is retained, or upon casts of the dorsal surface they are quite obsolete The small basal or third glabellar lohes are usually quite distinctly separated from those in front, hut occasionally show a tendency to coalesce with the others and form a single lobe on each side. In some species of Dalmanites (Phacops Lopatini, Schmidt, and Phacops Sibericvs, Schmidt), this coalescence is complete, and for such variations the sub-generic term Monorakos has been recently proposed (Schmidt. Hull, de I'acad. imp de sciences de St. Petersb., vol. xii, p. 417. 188G). Distribution. Dalmanites (Chasmops) anchiops: Oriskany sandstone. Walpole, Province of Ontario, in association with Phacops cristata, var. pipa, Streptorhynchus (Orthis) hipparionyx, Spirifera arrecta, Rensseleria ovoides. Upper Helderberg group. Abundant in the Schoharie grit, in the town of Knox and vicinity 64 PALAEONTOLOGY OF NEW YORK. of Clarksville, Albany county ; and at Schoharie, Schoharie county. In the Corniferous limestone, on Schultz's Farm, near Clarence, Erie county; Port Colborne, Province of Ontario; Falls of the Ohio. Dalmanites (Chasmops) anchiops, varieties armatus anil sobrimis : Schoharie grit, Albany and Schoharie counties. The variety armatus has also been found in the Upper Helderberg limestones at Arched Rock, Mackinac, Michigan. Dalmanites (Chasmops) Calypso. PLATE XI A, FIGS. 19-22 Ddhrumia Calypso, Hall. Descrip. New Species of Fossils, etc., p. 01. 1861. 'ypso, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 89. 1862. Dalmanites Calypso, Hall. Illustrations of Devonian Fossils, pi. xiii, figs. 1, 2. 1876. General Form and Proportions. Outline elongate-elliptical, posteriorly sub- acuminate; length to width as 2 to 1. Surface convex, axially elevated, sub-equally trilobate. Cephalon. Outline sub-semi-circular, length to width as 1 to 2. Border thin, moderately broad, flattened on the anterior limb, depressed at the sides, and produced at the genal angles into conspicuous spines. Surface convex, somewhat flattened axially. Facial Sutures taking their origin on the lateral margins just in front of the genal spines, thence following a direction normal for this genus. Upon the fr hecks they lie in a broad, conspicuous sulcus, which unites with the sulcus at the base of the eye and becomes obsolete upon the margin. Glabella elongate-sub-pentagonal, widest anteriorly; length and width equal. Surface gently rounded, depressed above. Anterior or frontal lobe large, transversely sub-elliptical or sub-rhomboidal ; first pair of lateral furrows strong, inclined posteriorly and passing three-fourths the distance across the glabella; first and second glabellar lobes coalescing, r en i form, ele- vate,] at their outer margins ; second lateral furrows obsolete except at their proximal extremities, where they are represented by two deep depressions or]. its; third glabellar lobes inconspicuous, transverse and separated from the coalesced first and second lobes by the faint third pair of lateral furrows. CRUSTACEA. 65 The axial portion of the glabella between the lateral lobes is somewhat ele- vated, terminating in a narrow annulation formed by the coalescence of this part with the third pair of lobes. Occipital furrow narrow; occipital ring broad and strongly arched. Cheeks grooved and slightly flattened beneath the orbital ridge, falling away thence somewhat abruptly to the margins. The regular convexity of their surface is interrupted only by the sutural grooves. Eyes large, closely appressed to the glabella, and more elevated than any other portion of the cephalon. Visual surface lunate, lenses abundant. Pal- pebrum crescentic, narrow : palpebral lobe sloping rapidly from the coalesced first and second lobes of the glabella, from which it is separated by a sharp furrow. Thorax. Outline sub-quadrate lateral margins slowly approximating. Length and width equal. Surface conspicuously and sub-equally trilobate. Axis strongly arched, relatively narrow on the anterior margin, widening to the fourth or fifth segment, thence narrowing to the pygidium : segments transverse, or with a slight double curve, posteriorly near the margins and anteriorly over the axial line. Pleurce flattened above for one-half their width, and abruptly deflected at the sides. Each segment is strongly elevated near the axial furrow, and con- spicuously sulcate, the anterior limb, at the fulcrum or line of geniculation, being as broad as the posterior limb. The former becomes obsolete upon the lateral slope where the planes of articulation are broad. Pygidium. Outline sub-triangular, sub-equilateral ; width slightly greater than the length. Surface convex anteriorly, angulated on the axial line, and on the posterior portion sloping abruptly from this line to the margins. Axis arched, equal in width to one-fourth the width of the shield, sides appressed and sharply angulated upon the median line: evenly tapering to a termination, beyond wdiich an angulated ridge is continued to the margin : bearing twelve annulat'ions which are low, somewhat flattened and trans- verse, each one with a short, laterally compressed spine or spiniform node. 66 PALEONTOLOGY OF NEW YORK. The pleura are moderately broad and bear eleven or twelve low and flat annulations, which are grooved by fine impressed lines, and become obsolete upon the wide and slightly thickened border. Htpostoma. Elongate, sub-triangular; width on the anterior margin equal i.) the length. Anterolateral angles broadly auriculate ; lateral margins incurved and rapidly approximating. The posterior margin apparently bears five minute spines, one situated medially, and two on either side, but the only specimen observed is somewhat broken at this part, and its character cannot be satisfactorily determined. Margins thickened and sharply deflected. Cntrum low, depressed-convex. Posterior sulcus conspicuous; postero- lateral pits moderately strong and elongate. Surface Ornamentation. The glabella is covered with moderately strong and evenly disposed tubercles which become obscure or obsolete upon the cheeks and margin. The frontal lobe of the glabella bears a circular pit on the axial line just back of its centre. The segments of the thorax appear faintly pustulosc upon the axis; otherwise the surface is smooth or minutely granulose. Dimensions. The single entire individual known measures as follows. Body. Cephalon. Thorax. Pygidium. Hypostoma. Length 80 mm. 23 mm. 32 mm. 25 mm. 18 mm. Width 44 mm. 44 mm. 41mm. 30 mm. 18 mm. Observations. The pygidium of Dalmanites Calypso shows strong points of similarity with that of D. Erina. They differ, however, in these respects: (a) the type of D. Erina is faintly nodose along the axial line, but not angulate or spinose, (b) the shield is more depressed, (c) the outline is a broader curve, and (d) the border wider and usually somewhat unsymmetrical It may eventually become necessary, with a more complete knowledge of the latter species, to unite the two under on<' designation, but with our present material is seems rable to retain the species tentatively as distinct, Distribution. Upper Helderberg -roup. Corniferous limestone: Sandusky. Ohio: Falls of the Ohio, Ky.; Schoharie, N. Y. CRUSTACEA. G7 Dalmanites (Chasmops?) Erina. PLATE XI a. PIGS. 16-18. Dalmania Erina, Hall. I>i>sci\ >."•■« Species of I .. p. 62. 1861. Dalmania Erina, Hall. Fifteenth Kept. NT. V. state Cab. Nat. Mist., p. 90. 1862. Dalmanites Erina, Hall. Illustrations of Devonian Fossils, pi. xiii, figs. :'•. 1. 1876. The pygidium of this species only has been observed. Its outline is paraboloid. Surface depressed-convex. Axis less in width than one-third the width of the shield, elevated or suit- angular along the median line, evenly tapering to a termination just within the margin; bearing twelve to fourteen transverse or retrally curved iiiimi- lations which are thickened or sub-nodose on the axial line. Pleura depressed in an even curve to the margins; composed of eleven or twelve broad, low annulations, separated by narrow sulci and becoming obso- lete upon the broad border. Each annulation is grooved by a line impressed line. In casts of the lower surface the lines upon the annulations, the sulci between them and the nodes upon the axial line appear much stronger than upon the test. Border broad, thickened, sometimes widening irregu- larly toward the posterior extremity. From the termination of the axis a low but sharply angled ridge extends to the posterior margin. Surface minutely granulose, the granulations being more conspicuous upon the border. The differences between this species and Dalmanites Calypso are pointed out in the description of the latter species. Dimensions. An average specimen measures 18 mm. in length and 28 mm. in width; the largest specimen observed attaining a length of 31 mm , and a width of 40 mm. Distribution. Upper Helderberg group. Corniferous limestone: Eastman's quarry, Waterville, Oneida county; Canandaigua, Ontario county: LeRoy and Stafford, Genesee county ; Williamsville and Clarence, Erie county. PALAEONTOLOGY OF NEW YORK. Dalmanites (Chasmops) macrops. PL \TK XI 1!, FIGS. II. 15. lania mcKrops, Hall. Descr. New Species of Fossils, etc., p. 59. 1861. nacrops, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 87. 1862. — , — -. Illustration of Devonian Fossils, pi. xiii, figs. 9, 10. 1876. (Not mentioned in the explanation of t lie plate). A portion of the Cephalon is the only part of this .species known. It is lunate in outline, border narrow and thin. Glabella long, equaling four-fifths the length of the shield Frontal lobe sub-rhomboidal, one-third wider than long ; first pair of lateral furrows long, inclined backward and nearly meeting ; second lateral furrows obsolete except at their proximal extremities; third lateral furrows inconspicuous, inclined a little forward. The first and second glabellar lobes are coalesced and some- what more elevated than the highest point of the frontal lobe. The third pair of lobes is inconspicuous and transverse. Occipital furrow narrow and shallow ; occipital ring broad, rounded and strongly arched. Eyes very large, elevated above any other portion of the cephalon. Visual surface measuring 9 mm. in height, and bearing about 500 lenses. Palpebrum scarcely prominent ; palpebral lobe relatively small and closely appressed to the compound middle lobe of the glabella. Orbital sulcus distinct. The Cheeks appear to have been relatively small and depressed or flattened near the margin. Surface finely pustulose upon the glabella, smooth or granulose upon the cheeks and occipital ring. The single specimen by which this species is represented has a length of 20 mm., and a width of 38 mm., and presents about the characters which, from comparison with the species Dalmanites Calypso, might be expected in the cephalon of I). Erina. Whether the latter species, which is now known only from its pygidia, should be united with D. macrops must be left io a more complete knowledge of these fossils. Distribution. Upper Helderberg group. Corniferous limestone: Schoharie. CRUSTACEA. 69 AC I DAS T 1 D.H. ACIDASPIS, Murchison. 1839. ACIDASP1S CALLICERA, 11. Sp. PLATE XVI ii, KIGS. 1-13. General Form and Outline. Body ovate; anterior margin slightly transverse; lateral margins evenly converging from the base of the cephalon. Surface convex along the axis, depressed on the pleurae. Length to width as 4 to 3. Cephalon transversely sub-rectangular, anterior and posterior margins sub- parallel, lateral margins divergent at the genal angles. Width equal to rather more than twice the length. Facial Sutures beginning on the posterior margin, just within the genal angles, passing inward and forward over the eye-lobes, thence forward, con- verging slightly to the frontal margin. Glabella sub-quadrate, frontal lobe elongate, convex, elevated, extending from the frontal margin to the occipital furrow: sides parallel. Lateral lobes in two pairs, pyriform, the posterior pair the larger, and both separated from the frontal lobe by elevated furrows. The lateral lobes are included by a ridge which extends from the anterior limb of the frontal lobe to the eye and thence to the axial furrows. Occipital furrow narrow, becoming rapidly obsolete upon the cheeks. Occipital ring broad, arched and bearing a short central spine. Cheeks broad, slightly concave and sloping abruptly from the elevated eye- Jobes. Border moderately thickened and produced at the genal angles into long, slightly incurved, diverging spines; above this the margin is fringed with short spines which are reduced to mere denticulations in front. 70 PALAEONTOLOGY OF NEW YORK. Eyes small, remarkably elevated. Visual surface lunate, sub-semi-cylindrical, homo-corneal. Thorax convex, arched upon the axis, depressed and flattened upon the pleurae. Composed of nine segments. Axis having less than one-third the width of the body; margins sub- parallel. Upon the pleura the elevated limb of each segment is produced into a long marginal spine, sometimes equaling the width of the thorax. In front of this spine, upon each segment, is a short, bifurcate marginal spine, which is visible only when the posterior spine is broken away. Ptgidium short, lunate. Anterior margin straight. Axis abruptly terminating just within the posterior margin in two nodes or tubercles. In addition to the strong articulating ring, it bears a single annulation which extends across the pleune and is produced at the margin into long spines. Anterior to this pair of spines are three pairs, of which the first is shortest, and belongs to the articulating ring. There is also a single pair on the terminal border, making in all ten marginal spines upon the pygidium. Pleura flat. Surface ornamented with tubercles, which are crowded upon the lobes of the glabella, and irregularly disposed upon the cheeks. The segments of the thorax each bear a single row of strong tubercles, there being from two to four longitudinal rows upon the axis, and two longitudinal rows upon the pleura;. Upon the pygidium there are tubercles on the annulation, at the bases of the marginal spines, and at the termination of the axis. Dimensions. The smallest individual observed has approximately a length of ID mm., a width of 6.5 mm., and the largest a length of 21 mm. and a width of 14 mm. There is a similarity in the more general features between this species and Acidaspis tuberculatus, Conrad, from the Lower Helderberg. CRUSTACEA. 71 They niay, however, be distinguished by the strong occipital spine, the stouter marginal spines, and the more depressed and broader glabella in the latter species Distribution. Upper Helderberg group. Schoharie gril : Near Clarksville, Albany county; Corniferous limestone: Caniillus, Onondaga county; in the decomposed chert boulders, Canandaigua, Ontario county; Cayuga, Province of Ontario. ACIDASPIS, Sp. PLATE XVI B, FIG. 14. A single large pygidium from the decomposed chert at Port Colborne, Ontario, is shorter than in the foregoing species, the axis more arched, with a very strong articulating ring and a single annulation which becomes obsolete on the flat pleura?, but the bases of two stout marginal spines represent its termination on the postero-lateral border. The rest of the margin appears to be fringed with small, irregularly disposed spines and spinose tubercles. The termination of the axis is less abrupt than in A. callicera and without the char- acteristic tubercles of that species. The specimen has a length of 9 nun., and a width of 21 mm. ACIDASPIS KOMINGERI, 11. Sp. PLATE \\ I B, PIGS. 15-18. Pygidium comparatively large; surface very convex; anterior margin transverse. Axis conspicuous, short, unsegmented, bullate ; outline circular ; articulat- ing ring broken away, the transverse furrow behind this ring being shallow and narrow. The posterior portion of the axis is sub-spherical, slightly constricted about the base and Hanked on the anterolateral margins by two elongate nodes. The longitudinal furrows are conspicuous, being abruptly depressed near their anterior terminations. Border broad, depressed about the axis, flattened toward the margin, bearing twelve long spines. Of these, ten are marginal, the third spine on either side being very much longer than the others and attaining a length equal to more than five times the length of 72 PALAEONTOLOGY OF NEW YORK. tin' axis. The three pairs of lateral spines are curved regularly backward, while the four posterior spines appear to have been straight, and but slightly divergent. Within the margin, and just above the bases of the long third pair of spines, was another pair which, judging from the diameter of the broken base, must have had fully the length of the third pair. These spines were inclined at an angle of nearly forty-five degrees to the surface of the border. The actual length attained by all these spines is not indicated except for the third pair: judging, however, from their broken sections it is evident that they were of very considerable length. Across the posterior border the bases of the spines art' continued as low ridges to the edge of the axis. Surfaci Ornamentation. The bulbiform termination of the axis is covered with closely set pustules of uniform size. The anterior furrow and the border are minutely granulose, and the surface of the spines is marked by elevated, frequently interrupted striae, which converge at an acute angle on the upper surface of the spine; towards the extremity of the spines these lines become stronger and much rounded, giving the surface a coarsely ridged appearance. Dimensions. The single specimen observed has a width across the anterior margin of 9 mm., a length of 8.5 mm. to the posterior margin, and of 33 mm. axially, as far as the apex of the third pair of spines. Observations. This extravagant form of Acidaspis is the only member of the genus as yet known in America from rocks younger than the Upper Helder- berg limestone. The great length of the caudal spines is equaled by no other known species of the genus and is approximated only by Acidaspis Dufresnoyi, Barrande. ' Distribution. Hamilton group. Little Traverse Bay, Michigan. We are indebted to Dr. < '. Rominger, of Ann Arbor, Michigan, for the discovery of this species, and li his favor, the i been made accessible for study and description. CRUSTACEA. 73 LICII AD.h. L ICH AS, Dalman. 1826. [s.-g.] T Eli AT ASP IS, Hall. 18G3. Lichas (Terataspis) grandis. PLATE XVII, FIGS. 1-6; PLATE XVIII, FIGS. 1,2; PLATE \l.\. FIGS. 1 7. Lichas grandis. Hall. Descriptions New Species of Fossils, etc., p. 82. 1861. Lichas grandis, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Ili-i . p. Hi) 1862. Lichas grandis, sub-genus? Terataspis, Hall. Sixteenth Rept. N. Y. Stat.- Cab. Nat. lli.^t.. p. 223. 1863. Lichas superbus, Billings. Canadian Naturalist and Geologist, vol. vii, IV:'. -1. p. 239. 1875. Acidaspis (Terataspis) grandis. Hall. Illustrations of Devonian Fossils, pis. xvii. xviii. lsTD. Cephalon very prominent in front, abruptly depressed behind ; length to width between the eyes as 5 to 4 ; to greatest width as 5 to 7. Frontal border broad, flat and sloping outward; margin not thickened. The facial sutures begin on the posterior margin a short distance outside the axial furrows, and slope obliquely forward, curving abruptly and passing thence directly inward to the eye; thence directed outward in a broad curve to the anterior margin. Glabella sub-quadrate in general outline; anterior lobe ovoid or ellipsoid, extremely prominent, tumid, evenly convex and strongly constricted about the base; length ecpial to five-eighths the length of the glabella; length to width as 6 to 5. Longitudinal furrows very broad and deep, merging at t he posterior margin of the frontal lobe, and forming a broad, median depression, which narrows for a short distance and widens thence to the occipital ring. The two lateral lobes are broad, directed posteriorly, and at the summit each one is produced into a conspicuous compound spine, the inner branch of which is the longer, reaching beyond the height of the anterior lobe, and projecting over the occipital ring. These lateral lobes may be regarded as the coalesced first and second pairs, the third pair being obsolete or indicated only by a faint elevation of the crust near the occipital ring, crowned by a few strong 7 1 PALEONTOLOGY OF NEW YORK. tubercles. Then' appears to have been also a strong spine near the ocular node jusl outside the lateral lobes. The occipital furrow is broad and -hallow over the axis, deeper along the abruptly sloping sides of the cheeks; the occipital ring is ver\ broad, depressed-convex, with a gentle anterior and an abrupt posterior slope, and narrows rapidly towards the axial furrows; on its posterior edge it bears a row of from six to eight strong clavate tubercles. Cheeks separated from the lateral lobes by a faint furrow, which leaves the position of the eyes elevated, and gives to the lixed portions of the cheeks an abrupt anterior and posterior slope. The free portion, as far as can be judged from two fragments, was somewhat constricted or narrowed beyond the terminations of the facial sutures, and its posterior margin carried a series of more or less irregular, tubercled spines. The genal extremities were acute and attenuate, and the anterior margin regular. The surface of the cephalon is covered with coorse tubercles which are largest on the posterior extremity of the anterior lobe, but are almost all absent on the median depression behind this lobe, and are obsolete on the constricting furrow about its base. Thorax. The character of this part of the animal is known only from two impressions, one of a segment of a small individual, the other the axial arch of the segment of a large example. The segment shows a relatively wide and strongly arched axis and narrow pleurae deflected at about the middle of their length. The axial arch bears two strong, straight, divergent spines, reaching a height equal to the width of the axis, and apparently directed posteriorly. Pvgididm semi-circular in general outline, wider than long; strongly spinose on the lateral and posterior margins; anterior margin nearly transverse. Axis relatively wide, being about one-third as wide as the shield on the anterior margin, and tapering rapidly to an elevated termination at a point about hall' way across the pygidium. It bears two annulations, behind which are situated a pair of conspicuous tubercles, and between this point CRUSTACEA. 75 and the apex of the axis are three linear, transverse furrows. The apex appears to have borne a strong, probably spiniform, tubercle. The pleura bear three broad, lobe-like annulations, which become obsolete before reaching the margin, and probably each one bears a conspicuous tubercle at its summit. They are strongly sulcate, the anterior limb being very narrow, and the posterior limb broad and inflated toward the margin. The post-axial area is elevated above the margin, though depressed below the pleurae and axis. The border is broad and bears a row of eight marginal spines, one at the termination of each of the three annulations, and two on the posterior limb. These spines are very long, increasing in length posteriorly, incurved towards the tips, and covered on the upper surface and the margins with narrow, acute spinules. The entire surface of the p\ gidium was covered with strong pustules, the larger of which appear to have been acute at the apex. A very small pygidium, which is referred with some doubt to this species, bears narrow annulations which extend to the margin, rendering the border obscure or obsolete. This feature may eventually prove to be of specific importance. The pygidium is known only from imperfect specimens, the most complete example showing nearly the entire under surface of the shield and portions of several of the spines. The type specimen of Lichas superbus, Billings, retains a large portion of the pygidium, and as this occurs in juxtaposition with a cephalon of Lichas grandis, little doubt can remain that the pygidia and cephala there described belonged to the same species. Dimensions. A very large fragment of a cephalon has the following dimen- sions: length, 110 mm.; width between the eyes. 82 mm ; width along the occipital ring to the termination of the facial suture, 121) mm. Fragments of smaller individuals have also been found. A singh -mall thoracic seg- ment measures 51 mm. transversely, and the spines on its axis are 10 mm. in length. A large pygidium has a length of 119 mm. to the apex of the posterior spines, and probably had a width of L35 mm., -to the tips of the first lateral spines. The smallest pygidium observed is 18 mm in length. That the individuals of this species sometimes reached colossal dimensions 76 PALAEONTOLOGY OF NEW YORK. is shown by the size of some of the fragments of the head, for in the genus Lichas the cephalon is usually very short in comparison with the length of the thorax and pygidium. An appearance of considerable length in this part is sometimes produced by a very protuberant and elevated glabella as in Lichas celorhin and others; but it is found on a careful comparison of the dimensions of the head, thorax and pygidium, in the rare instances of species in which the parts have been preserved in juxtaposition (Lichas Boltoni, L. palmata, L. scabra, L. gibbus), that their proportional length is as 1 to 1.6 to 1 (not inclusive of spines); and upon this basis a restoration of Lichas grandis from the very large fragment of a cephalon figured on plate xviii, indicates thai the entire length of the animal to the extremity of the tail-spines would have been about 480 mm., or upwards of 19 inches. This estimate is in harmony with the relative proportions of the cephalon and pygidium fur- nished by the type specimen of Lichas superbus, Billings. In the descrip- tion of L. superbus (Billings, Inc. tit.), mention is made of a fragment of the cephalon in which the frontal lobe has a length of three inches. This would be one-third larger than the frontal lobe in the individual here restored, and if the increase in the size of this part was accompanied by the same relative increase in the length of the animal, this fragment belonged to an individual probably not less than two feet in length, a size unequaled by that of any other known trilobite. Observations. The marked prominence of the anterior lobe and the some- what suppressed lateral lobes of this species suggest a similarity to forms of the genus Acidaspis, and this feature, together with the striking spinose character of the pygidium, led to the temporary reference of the species to that genus in the Illustrations of Devonian Fossils (ioc. cit.). The character of the subdivisions of the glabella appears, however, to be more in harmony with those of Lichas, and similar in general features to those of L. Eriopis, /,. hylaus, L. gryps and L. dracon. The pygidium of Lichas, though usually with hut three pairs of spines, occasionally has four (L. Eriopis, L. ptyonurus), while in Acidaspis the pygidium is very short, with two long postero-lateral spines and a fringe of shorter spines, and is not subject to much variation. CRUSTACEA. ' 77 The type of Lichas superbus, Billings, is a specimen of average dimensions, preserving both cephalon and pygidium, and agrees in every essential feature with the type of Lichas grandis. Distribution. Upper Helderberg group. Schoharie grit: Schoharie, Scho- harie county: Thompson's Lake. Knox and near Clarksville, Albany county. Upper Helderberg limestone: Cayuga, Province of Ontario. [s.-g.] CONOLICHAS, Dames. 1877. Lichas (Conolichas) hispidus, n. sp. PLATE XIX A, FIGS. 14, 17, 18. Acidaspis [Terataspis) Ehiopis, Hall. Illustrations of Devonian Fossils, pi. xix. figs. S. 9. 1876. The pygidium, which is the only portion of the animal observed, presents in general proportions, a close similarity to pygidia referred to the species Lichas Eriopis. The marginal spines in L. hispidus are shorter and stouter. the terminal spine or lobe quite small but distinct, and the axial node ele- vated, but without a spine : the pleuras are covered with rows of coarse and fine tubercles, without spines. In a single specimen the axis bears as many as four transverse rows of tubercles, representing annulations. The type specimen of this species is from the Schoharie grit, and in the Illustrations of Devonian Fossils {he. cit.), was provisionally referred to L. Eriopis. The finding of pygidia in the Upper Helderberg limestone, similar in all the above particulars, seems to establish this form as a distinct variation, which may be tentatively accorded a specific value. Dimensions. In two specimens the length is to the width as 9 to 16 mm. and as 18 to 30 mm. Distribution. Upper Helderberg group. Schoharie grit: mar Clarksville, Albany county; Corniferous limestone: LeRoy, Genesee county. 78 PALEONTOLOGY OF NEW YORK. LlCHAS (CONOLICHAS) ErIOPIS. PLATE XIX a. FIGS. 2-13, 15,16. : The genus Dicranogmus was established by Corda {he. cit.) for a form of Lichas, in which the longitudinal furrows of the glabella become obsolete before reaching the anterior margin. It is stated by Barrande (Syst. Sil. du centre de la Boheme, vol. i, pp. 43, 609), that the group was founded upon a single very fragmentary specimen, and it has not been accorded recog- nition by him for the reason that " le prolongement plus ou moins grand des sillons de la glabelle esl un caractere tres-variable dans divers types" (p. 609). It is nevertheless true that very few species of the genus Lichas bear longitu- dinal furrows which become anteriorly obsolete at so great a distance from the frontal margin as in the species L. pustulates, Corda, which served as the type of Dicranogmus ; and it may be questioned whether in any species of Lichas, except those following the type of Dicranogmus, the anterior longitudinal furrows become obsolete before reaching the margin. No evidence of this fact is shown in the species described by Barrande, Angelin, Dames and Schmidt, and none is found in any other American species of Lichas. The species Lichas gibbus, Angelin, Lichas simplex, Barrande ( = Dicranogmus pustulates, Corda), and IJrhas ptijonurus have in common the characteristic obsolescence of the anterior longitudinal furrows and serve to form a distinct subdivision of the genus. Distribution. Niagara group. Coralline limestone : Schoharie, Schoharie county. CRUSTACEA. 89 PRO ET I DM. PROETUS, Steininger. 1831. Proetus Conradi. PLATE XX, PIG. 9. PLATE XXI. FIGS. 27. 28; IND PLATE XXII, FIG. I. Proetus Conradi, Hall. Descr. New Species of Fossils, etc., p. 69. 1861. Proitus Conradi, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 97. LS62. Proetus Conradi, Hall. Illustration? of Devonian Fossils, pi. xx. fig. ti (not tigs. 5, S, '.)). ls7>;. Proetus marginaZU, Hall. Illustrations of Devonian Fossils, pi. xxi. figs. 27, 28. IS76. General Form and Proportions. Outline elliptical or sub-ovate: length to width as 3 to 2. Surface convex: depressed or flattened near the longitudinal furrows. Cephalon semi-elliptical; length to width as 1 to 2. Border very broad, gently convex toward its inner edge, sloping evenly outward and at the outer edge faintly reflexed ; at the genal extremities produced into short, stout spines, extending as far as the fourth thoracic segment. Facial Sutures normal, crossing the anterior border more directly than in Prottus angustifrons. Glabella short, slightly longer than wide ; sub-ovoid; tangent at its anterior extremity to the inner margin of the border. Surface depressed-convex, slightly Rattened above. Casts of the lower surface show well-defined basal lobes, and under favorable preservation the other glabellar lobes would probably be apparent. Occipital furrow deep; occipital ring moderately broad and elevated ; occipital lobes inconspicuous on the dorsal surface, but quite large in the internal cast. Cheeks narrow, broadly flattened about the eyes, and abruptly deflected to the marginal sulcus. The most elevated portion of the checks lies in the angle made by the marginal sulcus and occipital furrow. 90 PALEONTOLOGY OF NEW YORK. Eyes proportionally large, reaching anteriorly almost to the marginal sul- cus. Orbital ridge well developed, its base lying lower than the surface of the cheek. Visual surface elongate-lunate. Thorax sub-quadrate, slightly wider than long. Axis broadly arched, having somewhat more than one-third the width of the body. Segments transverse, narrow, with vertical sides. Pleura, flattened near the longitudinal furrows for more than one-third their width, rounding thence to the margin; conspicuously sulcate. PrGlDIUM sub-elliptical in outline, surface evenly sloping posteriorly ; length slightly less than twice the width. Border broad, limited within by a low, faint sulcus; convex toward its inner edge, sloping regularly outward, some- times slightly concave. Axis depressed-convex, relatively narrow, having less than one-third the width of the shield on the anterior margin; tapering rapidly to a broad, scarcely elevated extremity just within the marginal sulcus, behind which, in the axial line, lies an obscure node-like elevation ; composed of eight or ten broad and tlat annulations, which are depressed just within the marginal furrows, and are gently recurved over the axial line. Pleura moderately broad and evenly convex. Annulations very indistinct, three or foui- of which and in rare instances a fifth may be counted on each side. These are all sulcate, the anterior and posterior limbs of the annula- tions having equal size. All the annulations become extinct at the marginal sulcus. Htpostoma sub-spatulate, verj convex, abruptly depressed and broadly auri- culate on the antero-lateral margins. Anterior margin slightly refiexed; posterior and postero-lateral margins narrow and flattened. Posterior sulcus conspicuous. The centrum also bears a low sulcus on its posterior portion. Surface, on its more elevated portions, marked by scattered granules, which are mosl conspicuous upon the cephalon and the thoracic segments, but are faint or obsolete upon the pygidium. CRUSTACEA. 91 Dimensions. Of this species but two individuals retaining the parts in juxtaposition have been observed, although detached portions of the bod} are not of uncommon occurrence. Both of the entire example- are more or less enrolled, the better preserved specimen having approximately the fol- lowing dimensions: Body. I '' -| 'i Thorax. Pygidium. Length 36 mm. TO mm. 18 mm. 8 mm. Width 20 mm. 20 mm. 16 nun. L2 mm. Observations. Proitus Conradi is a well-defined species, approximating how- ever some of its associates, but readily diagnosed by its short, ovoid glabella and sloping pygidium, characters which are persistent and which serve to distinguish it from its nearest ally, Pr. angustifrons. Distribution. Upper Helderberg group: In the Schoharie grit at Schoharie, Schoharie county, and near Clarksville, Albany county. Proetus angustifrons. PLATE XX, FIGS. 1-;,; an-i, PLATE XXII, PIGS. 1-.".. Proitus angustifrons, Hall. Descr. New Species of Fossils, etc., p. 70. L861. Pro, tus angustifrons, Hall. Fifteenth Kept. N. V. state Cab. Nat. Hist., p. 98. 18H2. Proitus angustifrons. Hall. Illustrations of Devonian Fossils, pi. xx.. 6gs. I !. 7 1876. Our knowledge of this species is limited to portions of the cephalon and the pygidium. The Cephalon appears to have been semicircular in outline, with a broad border slightly thickened near the marginal sulcus, and produced into short spines at the angles of the cheeks. The facial sutures are normal in their direction, crossing the frontal border very obliquely. Glabella elongate-sub-conate, tapering rapidly to a rounded, narrow ante- rior extremity, tangent to, but not encroaching upon the frontal margin. Length one-half greater than width. Surface depressed-convex, flattened above. Traces of three pairs of lateral furrows are faintly visible upon 92 PALEONTOLOGY OF NEW YORK. the test of favorably preserved specimens, and more clearly seen upon casts of tin' lower surface. Occipital furrow shallow and narrow; occipital lobes transverse, inconspicuous; occipital ring broad and flat, becoming narrower upon the cheeks, and bearing a central tubercle. Cheeks depressed or broadly flattened on the summit beneath the orbital ridge, thence rounding in all directions to the broad border. Eyes moderately large, orbital ridge distinct; visual surface sub-crescentic. Pfgidium sub-semi-elliptical, slightly emarginate behind. Surface convex. Axis elevated, arched, longitudinal furrows deep ; width on the anterior margin about one-third the width of the shield ; annulations seven or eight, slightly flattened and with a gentle retral curve over the axial line. • Pleura sloping evenly to the margin, and bearing five or six sulcate annu- lations, which are separated by broad, shallow furrows, the anterior and posterior limb being of about equal size. The annulations become extinct at i be broad, smooth, sloping border. Surface of the test smooth, or covered with fine granules or obsolescent tubercles. Upon the glabella, cheeks and frontal border the ornamentation is faint ; upon the pygidium it is more conspicuous each pleural annulation bearing two rows of sharp granules, one on each limb. The axis is covered with scattered granules. Dimensions. A fragment of the cephalon, consisting of the intra-sutural portion, has a length of 11 mm., a width between the eyes of 7.5 mm. An average pygidium measures 11 mm. in length, and 18 mm. in width. Observations. This species was erected upon detached fragments of cephala and separate pygidia occurring in comparative abundance associated in the Schoharie -rit. In many features these parts are closely allied to those of Proelus Conradi, also an abundant species and intimately associated with this. The differences in the two forms are as follows: In Proetus angustifrons (a) the glabella is longer, more rapidly tapering and less distinctly lobed ; (b) the summit of the cheeks is rounded and the lateral slopes less abrupt; (c) the CRUSTACEA. pygidium is shorter, the axis being broader and more abruptly elevated, the lateral slopes less evenly convex, the pleural annulations more distinct and numerous, the posterior border emarginate. In Proetus Hesione the pygidium is much longer and hears more annulations. Distribution. Upper Helderberg group. Schoharie grit: Near Clarksville, Knox and elsewhere, Albany county; Schoharie, Schoharie county. Pkoetds Hesione. PL VII. XX, FIGS 15, 16. Proetus Hesione, Hall. Descr. New S] ies of Fossils, etc., p. 70. 1861. Proihis Hesione, Hall. Fifteenth Rept. N. V. state Cab. Nat. Hi I . p 98. 1SH2 Proetus Hesione, Hall. Illustrations of Devonian Fossils, pi. x\. figs. 15, 16. 1876. Pygidium semi-elliptical, length to width as 2 to 3. Surface axially elevated, depressed-convex on the sides. vim relatively narrower than in the associated species of this genus, having a width slightly less than one-third the width of the shield on the anterior margin; longitudinally arched, margins tapering slowly to a rounded, scarcely elevated apex just within the posterior border; composed of ten or eli ven annulations which have a retral curve over the axial line. Pleura depressed near the longitudinal furrows, and sloping evenly to the border; composed of eight annulations, each of which is distinctly sulcate for its entire length, and all terminate abruptly at the marginal sulcus. Border broad, evenly sloping, thickened on its inner edge and gently concave. Surface faintly pustulose, the pustules heing arranged in rows upon the annulations and scattered irregularly over the border. Length 15 nun., width 21 mm. The single pygidium which has served as the type of this species, presents characters so unlike those of the associated species that it will he readily recognized as distinct. From Proetus angustifrons and P. Conradi it differs in its longer pygidium and more numerous annulations. and is in some respects allied to P . planimarginatus, Meek, of the Upper Helderberg limestone of Sylvania, Ohio. 94 PALEONTOLOGY OF NEW YORK. The latter species lias the same number of annulations on both axis and pleura?, and the same general outline; its axis however is more slender, the axial annu- lations transverse and the border less conspicuous and more flattened. Distribution. Upper Helderberg group. In the Schoharie grit, at Schoharie, Schoharie county. Proktus, sp. ? PLATE XXn, FIGS. 5, R. \ ingle imperfect cephalon, and two pygidia from the Schoharie grit, differ- ing from those of any species previously described from this horizon, indicate the existence of at least one additional species of Proitus. The Cephalon is semi-elliptical in outline, the glabella ovoid and ver}' convex, its anterior extremity tangent upon the frontal border, and the surface without apparent traces of transverse furrows. The frontal border is very broad and sloping; eves relatively small, orbital ridge unusually conspicuous, beneath which the surface of the cheek is grooved, somewhat flattened and thence abruptly deflected to the marginal sulcus ; its extremities were evidently pro- duced into short spines. The occipital furrow is narrow and sharp; the occipital ring broadly rounded. The specimen measures 12 mm. in length and 28 mm. in width. The Pygidia exist in the form of casts, and there is no evidence that they belong to the species represented by the cephalon. They are much shorter than in P. angustifrons or P. Conradi, show but six annulations upon the axis and three or four upon the pleuras. Distribution. Upper Helderberg group. Schoharie grit: The cephalon is from Schoharie, Schoharie county; the pygidia from the towns of Knox and Clarksville, Albany county. Proetus curvimarginatus, n. sp. PLATE XXII, FIGS. 13-19. General Form and Proportions. Body ovate or sub-elliptical. Surface sub-equally trilobate, convex along the axial line, strongly deflected at the margins. Length to width as 2 to 1. CRUSTACEA. Cephalon semi-elliptical in outline, slightly produced anteriorly ; border broad, depressed by the wide marginal sulcus and strongly reflexed : produced at the genal angles into stout spines which extend as far as the fourth thoracic segment. Length to width as 1 to 2. Facial Sutures normal; points of intersection with the frontal margin relatively distant. Glabella sub-triangular or conate : convex, tumid anteriorly and elevated along the median line; abruptly depressed toward the frontal border. Length equal to five-sixths the length of the cephalon; width at the base more than one-third the width of the same. Lateral glabellar furrows in four pairs; first pair short, transverse, situated at one-third the length of the glabella from the anterior extremity: second pair longer, inclined slightly backward ; third pair still longer and with a greater posterior inclination ; fourth pair longest and deepest, each furrow curving to meet the occipital furrow at one-third the distance across the base of the glabella; accessory furrows - conspicuous, oblique. The lobes of the glabella increase in size backward, the fourth pair being large and obliquely sub-triangular. They are followed behind by large, transverse, occipital lobes, which are distinctly circumscribed by the bifurcated occipital furrow. Occipital furrow shallow on the axis, increasing in width and depth upon the checks: occipital ring broad, flat, depressed below the glabella, and narrowing on the cheeks. Cheeks convex about the orbital node, slightly flattened above, abruptly depressed to the broad marginal sulcus and recurved upon the margin. The marginal sulcus extends into the cheek-spines making them concave. Eyes lunate, relatively small and very closely appressed to the glabella. Palpebral sulcus shallow and elevated. Thorax sub-rectangular, lateral margins gently converging posteriorly : sub- equally trilobate. Axis convex, prominent, widest at about the fourth segment, with margins slightly rounding thence to the pygidium. Segments transverse, Hat and thin. 96 PALEONTOLOGY OF NEW YORK. Pleura flat for one-half their width, thence abruptly deflected to the lateral margins Each segment is grooved by a sharply impressed furrow which becomes obsolete at the articulating plane. Pyqidium semi-elliptical, sometimes a little produced at the posterior extremity. Length to width as 4 to 5. Surface elevated, flattened above, deflected at the sides. Border broad, widening posteriorly and strongly curved upward. Axis convex, tapering evenly to a blunt, somewhat elevated termination just within the margin, and bearing thirteen or fourteen annulations, which an- marked by a faint, impressed longitudinal groove or line just above the axial furrows. Each annulation is obliquely flattened and makes a double curve in crossing the axis, sloping forward for about one-fourth the distance; being angulated at that point, just above the impressed line, and thence bending backward in a broad curve to the axial line, along which is a series of small nodes giving the axis the appearance of being medially angulated. Pleura flattened or very gently convex for about one-third of their width, thence rounding to an almost vertical slope upon the sides. Upon the poste- rior area the slope is less abrupt. They bear twelve annulations, which are separated by moderately broad furrows, and each is distinctly grooved for its entire length by a fine impressed line, visible upon the cast as well as on the dorsal surface. The anterior annulations encroach for a short distance upon the border. An bypostoma found in association with abundant fragments of this species is sub-triangular, centrum elongate, regularly convex, anterior margin narrow and deflected; anterior angles broadly sub-auriculate ; postero-lateral depres- sions long but not continuous; posterior sulcus prominent and posterior lingua short. Surface. Ornamentation. The cephalon is covered with fine tubercles and granules, which are most abundant upon the glabella, and are also faintly visible upon the segments of the thorax and the annulations of the pygi- be inter-annular grooves of the pygidium appear to be punctate. CRUSTACEA. 97 Dimensions. The only individuals observed in which the parts arc not detached, measure as follows: a- Body. Cephalon. Thorax. • Pygidium. Length 52 mm. 20 mm, L5 mm. 17 mm. Width 29 mm. 29 mm. 27 mm. 24 mm. b. Length 38 mm. 14 mm. 12 mm. 12 mm. Width 25 mm. 25 mm. 21mm. 18 nun. Observations. In the form and furrows of its glabella, and in the contour of its pygidium, this species presents some points of similarity to Proetus macrocepha- lus, of the Hamilton group. The rapidly tapering and deeply furrowed glabella makes its earliest appearance here and is not exemplified by any other species as yet known in the Upper Helderberg formations. Proetus Haldemani is also a close congener, but in these forms specific differences will he found in relative proportions and the number and character of the pygidial annulations. Distribution. In the sandstone at Pendleton, Indiana, associated with l'n>,///s latimarginatus and Conocardium cuneus, a horizon probably corresponding in age with the Schoharie grit of New York. Proetus latimarginatus, n. sp. PLATE XXII, FIGS. 7-12. General Form and Proportions. Outline elliptical, length to width as 2 to 1. Surface conspicuously trilobate, convex, deflected on the marginal area. Cephalon semi-elliptical in outline; border broad, flat, thickened by doublure and produced into stout spines at the angles of the cheeks. Length to width as 5 to 7. Facial Sutures taking their origin close within the genal angles, passing forward very obliquely over the occipital ring to the eye-lobe, cutting the anterior margin at points relatively distant, and approximating upon the doublure, PALEONTOLOGY OF NEW YORK. Glabella depressed-convex, slightly flattened above and posteriorly elevated on the axial line; long, conate, extending to the frontal border. Width at the base mentor than one-third the width of the shield. Lateral furrows obscure, but indications of three pairs may be observed. Occipital lobes comparatively large ; occipital furrow narrow, bifurcating near the axial fur- rows to include the occipital lobes, and becoming very deep upon the cheeks ; occipital ring broad and flat. Clinks convex, depressed about the base of the eyes, thence somewhat abruptly deflected to the marginal sulcus and occipital furrow. Eyes comparatively small, approximate, attaining the elevation of the glabella. Palpebrum small; palpebral lobes depressed, obscure; palpebral sulcus shallow. Thorax sub-quadrate, length to width as 2 to 3 ; margins nearly parallel ; sur- face equally trilobate. Axis evenly arched, widest at the fourth segment and tapering thence regularly backward. Segments flattened, transverse. Pleura flat for one-half their width and thence deflected in a moderately sharp curve to the margin. Each segment is grooved for two-thirds its length, and 1 leveled upon the outer third by the articulating plane. Pvgidiom parabolic in outline, length to width as 3 to 5; evenly convex; bor- der broad, flat or slightly sloping. Axis prominent and evenly tapering to an abrupt and somewhat elevated termination just within the posterior border, with which it is connected by a low ridge. Indications of seven or eight transverse annulations appear on the axis, exclusive of the articulating ring, which is more conspicuous than any of the others. Pleura evenly sloping to the lateral and posterior margins. Articulating ring very conspicuous; annulations obscure, almost obsolete. Four are visible in favorably preserved specimens, and all are depressed above and faintly grooved. CRUSTACEA 99 Dimensions. An average individual affords the following measurements: Body. Ceph Thi rax. • rlium. Length 43 mm. L6 mm. M nun. L3 mm. ■■- Width 23 mm. 23 mm. 23 mm. 21 mm. The largest pygidium observed has a length of 22 mm. and a width of 35 mm., the smallest a length of 9 mm. and a width of 15 mm. Distribution. In the sandstones at Pendleton. Indiana, associated with the preceding species. Proetus crassimarginatus. PLATE XX, FIGS. 6-8, 30-31 ; PLATE XXII, FIGS. 30-36 ; AND PLATE XXV, FIG; - rmem crassimarginatws, Hall. Geology of N. Y., Survey of Fourth Geol. Dist., p. 17-J. lij;. 5. 1843 /',-, ilus crassimarginata, Hall. Twelfth Rept. N. V. State Cab. Nat. Hist., p. 88. 1859. PhUlipsia crassi ' Canadian Journal, p. 362. 1861. rginatus, Ham,. Descr. New Species of Fossils, etc., p. 72. 1861. s crassimarginatus, Hall. Fifteenth Rept. N. V. S Nat. Hist., p. 100. 1862, Proetus crassimarginatus, Hall. Illustrations of Devonian Fossils, pi. xx, figs. 20-31. 1876. Proetus Conradi, Hall. Illustrations of Devonian Fossils, pi. xx. figs. 5, 8, 9. 1876. General Form and Proportions. Body regularly ovate, margins evenly tapering from the base of the cephalon to the narrow posterior extremity. Length to width at base of cephalon, as 2 to 1. Surface convex and strongly trilobate. Cephalon semicircular in outline, border broad, strongly recurved in front. more depressed and flattened at the sides, and produced at the genal angles into a broad, flat spine. Length to width as I to 2. Facial Sutures normal. Glabella large, sub-quadrate, semi-ovoid, narrowing slightly toward the anterior extremity ; length equal to five-sixths the Length of the cephalon, and width more than one-third that of the cephalon. Surface very convex. slightly flattened above; sides rising abruptly from the shallow marginal furrows. External evidence of the lateral furrows wanting. A single speci- men from which the test has been so far weathered as to leave only a thin film near the lower surface, shows four pairs and the accessory furrows, of the LOO PALAEONTOLOGY OF NEW YORK. same character and relative position as in Proetus folliceps. The.se furrows would undoubtedly appear in well preserved casts of the lower surface. Occi- pital lobes well denned but relatively small, and somewhat concealed by the prominent basal margin of the glabella; occipital furrow narrow upon the axis and but slightly widening upon the cheeks; occipital ring broad upon the axis and narrowing upon the cheeks. depressed at the summit about the base of the orbital ridge, sloping for a short distance abruptly, and thence more gently to the broad marginal sulcus. Eyes elevated, not large, approximate, probably attaining the height of the glabella. Thorax trapezoidal, lateral margins approximating; very strongly arched upon the axis, flattened upon the pleurae for about one-half their width and deflected toward the margins. Composed of ten segments which are trans- verse, somewhat flattened and grooved upon the pleurae. PrGlDlUM semi-ovate to semi-elliptical, convex and sloping evenly to the lateral and posterior margins : equally trilobate ; border thickened, moderately wide, its width slightly increasing posteriorly. In specimens from the Corniferous limestone of Ohio the axis is strongly arched, both longitudinally and trans- versely, and tapers to an obtuse and somewhat elevated termination. While many of the New York specimens conform with this type, examples from U illiamsville have the axis broader, more depressed, the margins tapering in a broad, outward curve to a, low, blunt apex, in these respects affording a close resemblance to the pygidium of Proetus Conradi of the Schoharie erit Under favorable preservation as many as fourteen annulations may be counted upon the axis. These present the feature noticed in Proetus iceps, being slightly angulated at a short distance within the margin and bent backward over the median line. The pleurse are marked by seven or eight annulations, the postem-lateral area being smooth. All the annu- lations with the exception of the articulating ring, become obsolete upon the border. CRUSTACEA. 101 Dimensions. The only entire individual observed is an enrolled specimen from Sandusky, Ohio, having the following dimensions: Body. Cephalon. rax. limn. Length 78 nun. 121 mm. 34 mm. 23 mm. Width 38 mm. .'is nun. 34 mm. 28 mm. Observations. Proetus crassimarginatus is not of rare occurrence in detached fragments, in the Upper Helderberg limestone in the Stales of New York and Ohio, but these are usually pygidia, the other parts being seldom seen. Pygidia which are manifestly identical with the limestone species are of common occurrence in the Schoharie grit Figures of such pygidia were erroneously referred to Proetus Conradi in the Illustrations of Devonian Fossils (loc. fit.). A single glabella found in association with these caudal shields agrees with those of the Corniferous limestone specimens. Distribution. Upper Helderberg group. Schoharie grit : Schoharie, Scho- harie county ; Knox and near Clarksville, Albany county. Corniferous lime- stone : Clarence and Williamsville, Erie county; Lime Rock, near LeRoy, and Stafford, Genesee county; Phelps and Canandaigua, Ontario county: Port Col- borne and Cayuga, Province of Ontario ; Sandusky, Ohio. Proetus folliceps, n. sp. PLATE XXIII, FIGS. 3-8. General Form and Proportions. Body elongate, outline sub-elliptical, lateral margins nearly parallel. Length to width as 8 to 5. Surface convex, anteriorly gibbous, conspicuously and sub-equally trilobate. Cephalon short, semicircular, border Hat, moderately broad, horizontal ante- riorly, becoming deflected toward the genal extremities, which are broadly rounded and not produced. Surface very convex, equally trilobate. Length to width as 1 to 2. The facial sutures take their origin just within the genal angles, run very obliquely across the occipital ring to the outer angle of the occipital lobes, thence rise abruptly to the eye-lobes and pass, with slight divergence, down L02 PALAEONTOLOGY OF NEW YORK. the steep frontal slope, curving and approaching each other at the edge of the frontal border and uniting upon the doublure. Glabella sub-pyriform, very convex, longitudinally arched, rising abruptly on all sides from the lateral furrows, which are not deeply impressed; gibbous on the anterior slope, slightly flattened at the summit. Length equal to four-fifths the length of the cephalon; width at the base more than one-third that of the cephalon. Four pairs of lateral furrows and one pair of acces- sory furrows are discernible upon the cast of the lower surface, but upon the crust only the stronger of them can be seen as faint lines interrupting the ornamentation. The first pair is situated at about one-third the length of the glabella from the anterior margin, and appear as faint elongate pits not distant from the marginal furrow. The other three pairs are longer and inclined backward, none except the fourth pair extending to the mar- ginal furrow. The accessory furrows take their origin just in front of the proximal ends of the fourth furrows, and are strongly inclined backward. The occipital lobes are moderately strong in the cast but are inconspicuous where the crust is retained. Occipital furrow narrow, the anterior side nearly vertical and the posterior side almost horizontal, widening on the cheeks and continuous with the marginal sulcus. Occipital ring broad, flat, narrowing to the axial furrows and widening again to the genal angles, bear- ing a small pointed tubercle upon the axial line. Cheeks grooved and depressed about the orbital lobe, thence abruptly de- llected to the broad margin. Eyes approximate, prominent, elevated to almost the height of the glabella ; orbital ridge conspicuous ; palpebral lobe small; palpebral furrow elevated and moderately deep. Thorax sub-rectangular, margins nearly parallel. Length to width as 1 to 1.3. Axis arched. Pleura flattened above for one-half their width, and thence somewhat ibruptly deflected. The segments are transverse, somewhat flattened, grooved upon the pleurae and beveled for one-half their length CRUSTACEA. 103 Ptoidium sub-semicircular, border broad, thickened and rounded. Surface con- vex, sloping more abruptly at the sides than posteriorly. Axis having less than one-third the width of the shield, tapering to a broad and blunt termination considerably within the posterior margin. It bears seven or eight annulations, which bend forward for a short distance within the axial furrows, are there sharply angulated and cross the axial line in a broad curve. Pleura with seven or eight annulations, each of which is broad, low, often indistinct, and very faintly grooved, all becoming obsolete upon the border. Length to width as 1 to 1.8. Dimensions. An average adult affords the following measurements: Body. Cephalon. Thorax. Pygidium. Length -- _ - 43 mm. 12 mm. 18 mm. 13 nun. Width 27 mm. 27 mm. 23 mm. 20 mm. The smallest individual observed measures 24 mm. in length and 14 mm. in width. Observations. This very characteristic and well-defined species is not of com- mon occurrence but is well represented by two entire individuals from the Cornif- erous limestone near Lelloy, Genesee county. One of these specimens, from which the crust of the pygidium has been broken away, shows, upon the very fine- grained, compact matrix beneath the axis, a series of paired impressions which, as preserved in the cast, appear as elevations. Each transverse axial groove near the axial margins, bears a pair of narrow elongate impressions, which take their origin upon the edge of the annulation and are directed backward and inward into the axial groove. Within this pair and upon the upper sur- face of the axial groove is a pair of obliquely transverse, lamellate impressions, separated by a faint thickening of each annulation upon the axial line. Upon the second, fourth and sixth axial groove, along the axial line, is a faint tubercle, indicating a circular pit or depression in the under surface of the test. The upper surface of the crust shows no indications of these characters. These paired impressions seem to be areas of insertion for somitic muscles, the mar- 104 PALAEONTOLOGY OF NEW YORK. ginal pair probably connected with the natatory appendages, the axial pair possibly attached to the branchial apparatus, or to the viscera. The function of the median pits upon alternate grooves is not understood. Similar though not so distinctly preserved markings have been noticed upon pygidia of Vroetus crassimarginatus, and the paired marginal impressions are well exhibited in a pygidium of Pkacops cristata, var. pi-pa (see description of this variety, page 18). Since the existence of a ventral membrane in certain species of trilobites has been demonstrated by Walcott, it may be assumed that the same structure has existed in this species also, and that the muscles, which are represented by these impressions, lay within this membrane. The specimens showing these features give no evidence of similar impressions upon the axial grooves of the thorax. Distribution. Upper Helderberg group. Corniferous limestone : LeRoy, Genesee county ; Schoharie, Schoharie county ; Marbletown, Ulster county, In boulders of decomposed chert: Canandaigua, Ontario county; Ann Arbor. Michigan. Proetus claeus. PLATE XX, FIGS. 12-14 ; and PLATE XXII, FIGS. 28-30. /', bus clarus, Hall. Descr. New Species of Fossils, etc., p. 71. 18G1. Proetus clants, B ill. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 99. 1862. Proetus clarus, Hall. Hlustrations of Devonian Fossils, pi. xx. figs. 12-14. 1876. General Form and Proportions. Outline elliptical or sub-ovate. Surface convex, conspicuously and equally trilobate. Length to width as 7 to 5. Cephalon. Outline semi-elliptical, faintly produced on the frontal margin. Surface, in normally preserved specimens, very convex, depressed about the border, which is broad, roundel or sloping, thickened on the posterior por- tion, and generally bearing a broad and shallow groove in front; produced at the genal angles into short, acute spines, which reach to the fourth thoracic The marginal sulcus, within the border, is deep and conspicuous. cur stac/:, i. L05 Facial Sutures normal, rapidly approximating on the broad frontal border Glabella broadly conate or sub-triangular, slightly constricted at the ante- rior angles of the eyes and rounded to the frontal extremity, which is closely appressed upon the marginal sulcus. Width at the base equal to one-third that of the shield. Length greater than the width. Surface convex, de- pressed above, and sloping in all directions to the cheeks. Lateral furrows obscure, obsolete upon the test, hut under favorable preservation sometimes visihle upon the cast of the lower surface. A single example shows three pairs and the accessory furrows or pits, the anterior of these pairs being numerically the second, the first pair being obsolete. They are all inclined posteriorly, and the last or fourth pair reach almost to the occipital furrow. Occipital lobes conspicuous ; occipital furrow narrow, scarcely widening on the cheeks; occipital ring moderately broad and Hat, narrowing slightly upon the cheeks. Cheeks depressed on the summit about the orbital lobe, and sloping with a somewhat abrupt curve to the strong marginal sulcus. Eyes relatively large, and closely appressed to the glabella. Palpebral lobe very small ; palpebral furrow shallow and elevated. Thorax sub-rectangular, lateral margins slowly approximating posteriorly. Length to width as 2 to 1. Axis broad and strongly arched, width upon the anterior margin more than one-third the width of the thorax. Sides evenly approximating to the pvgidium. The segments are flattened, transverse, or with a slight forward curve toward the axial line. Pleura flattened near the axis, and at about one-third their width deflected in a more or less abrupt curve to the margins. Pleural annulations groo\< d, the anterior limb of each becoming rapidly obsolete beyond the fulcrum. Pygidiu.m. Posterior outline the arc of a circle whose center is the middle point of the body ; when slightly compressed it is distinctly emarginate at the posterior extremity: border broad, moderately thickened. Length about one-half the width. L06 PALAEONTOLOGY OF NEW YORK. is convex and slightly arched longitudinally, tapering to a broad, blunt termination just within the margin. Width equal to one-third the width of the shield. The sides are appressed just above the axial furrows, by a series of oblique impressions, one upon each annulation. From seven to eleven annulations may be counted upon the axis, the first five having an anterior inclination near the margins, and a posterior curve over the median region; the posterior annulations are transverse. The pleura are depressed and curve evenly in all directions to the margins. The} bear lour annulations and traces of a fifth, and these are marked by line impressed lines. All the annulations become obsolete upon the border, the articulating ring, however, encroaching upon it. Surface smooth, sometimes granulose upon the glabella and segments. Dimensions. An average individual affords the following measurements : Body. 9 mm Width .20 mm. Length 29 mm. < 'ephalon. Thorax. Pygidium 12 mm. 9 mm. 8 mm. 20 mm. 18 mm. 15 mm. Observations. Proetus clarus appears to he the most abundant species of this melius occurring in the Upper Helderberg limestone, although entire examples are of extreme rarity. It shows many points of general and detailed similarity with the species Proetus Rowi of the Hamilton group, and Proitus anguslifrons of the Schoharie grit. From the former it may be distinguished by its relatively larger cephalon, a glabella very faintly encroaching upon the frontal border, smaller eyes, and fewer annulations upon the pygidium. In Proitus anguslifrons the cephalon is shorter, the anterior extremity of the glabella tangential upon the border, the pygidium more convex, its axis broader anteriorly, more de- pressed and more rapidly tapering, and its ornamentation more conspicuous. Distribution. Upper Helderberg group. Corn iferous limestone: Stafford and Lime Rock Quarries, near LeRoy, Genesee county; Caledonia, Livingston comity. Clarence. Kric county. Canandaigua, Ontario county ; Cherry Valley, Otsego count} ; Schoharie, Schoharie county; Falls of the Ohio. CRUSTACL'A 107 Proetos canaliculatus. PLATE XX, KIi.s 10, 11; ixn PLATE XXIII, FIGS Proctus canaliculatus, II mi.. Descr. New Species of Fossils, etc., p. 73. 1861. Proetus canaliculatus, Hall. Kit' nth Rept. N. Y. State Cab Nat. lli>t . ].. 101. 1862. Pro'itus canaliculatus, Hail. Ill Devo: an Fi ssils, pi. xx, figs. 10, 11. 1876. The original of this species is a fragmenl showing the intra-sutural port ion of the cephalon, and more complete material has not been observed, with the exception of a few detached cheeks which may safely he regarded as belong- ing to this form. The species is characterized by its violin-shaped glabella (genus Portia, Bur- meister), constricted at the anterior angle of the eye. and broadly rounded on the anterior extremity. Its length would he more than two-thirds the length of the cephalon, and its width apparently somewhat less than one-third that of the cephalon. The transverse furrows are indistinct upon the crust, hut appear to consisl of three pairs and the accessory pair. A cast of the lower surface would probably show a small anterior pair. The first pair visible is transverse, and the posterior pairs are inclined backward. All the glabellar lobes are taint. The occipital lohes are conspicuous; the occipital furrow narrow and deep; the occipital ring moderately broad and flattened. The border is very broad and tlat. and is grooved along the anterior limbus by two furrows, the anterior of which is narrow and close upon the edge, the other is broad and is separated from the frontal margin of the glabella by a rounded ridge Upon the cheeks these grooves become shallower and reduced to two planes, the in- terior and broader one horizontal, the anterior narrower and beveling. At the genal angles the border is produced into moderately long and stout spines, which are ridged upon the surface and minutely incurved at the tip. The eyes and palpebral lobes are comparatively large, the orbital ridge ele- vated, the cheeks flattened at their summit below this ridge, abruptly curving to the marginal and occipital furrow-. The surface is smooth upon the border, finch granulose upon the glabella, and pustulose upon the flattened summits of the cheeks. 108 PALEONTOLOGY OF NEW YORK. The doublure is strongly rounded and incurved, somewhat excavate at the geual angles, sharply convex and ridged upon the genal spines. Its surface is marked by longitudinally parallel, lamellose lines. Distribution. Upper Helderberg group. Corniferous limestone: Columbus, Ohio; Falls of the Ohio, Ky. Proktus Verneuili. I'l, \ I K XX, I IGS. is, l». Proitus VerTieuili, Hall. Descr. New Species of Fossils, etc , p. 73. 1861. ;;;. Hall Fifteenth Rept. N. V State Cab. Nat. Hist., p. 101. 1862. '!.< Verneuili, Hall. Illustrations of Devonian Fossils, pi xx, figs. 18, 19. 1S76. The cephalon and thorax of this species have been observed only in a con- dition tun incomplete for description. Pyo.ii.hum short, nearly twice as wide as long; outline sub-elliptical; surface convex axiallv, laterally depressed. Axis having one-third the width of the shield on the anterior margin, strongly convex, tapering rapidly to a blunt termination close upon the posterior border; bearing nine to eleven annulations, which have a retral bend over the axial line, where the first three or four are thickened and nodose. 'lip' pleura are Hat for a short distance, thence abruptly deflected and bear- ing seven or eight annulations which are faintly grooved. The border is broad, abruptly sloping for one-half its width, and near its inner edge hears a row of conspicuous nodes, which correspond in number and position to the annulations; outside of these the margin is smooth and concave. The best preserved specimen of the pygidium has a length of 4 mm., and ;i width of 7.5 nun. This species is well defined by the characteristic row of nodes upon the border, a feature which has been observed in many specimens and is undoubt- edly persistent. CRUSTACEA. 109 Distribution. Upper Helderberg group. Corniferous limestone: Williams- ville, Erie county ; Phelps and Canandaigua, Ontario countj ; Schoharie county. Proetus MICROGEMMA, 11. sp. PLATE XXII, FIGS 33, 34. Several detached ptgidia afford certain characteristic features in which they differ from described species. The shield is small and transverse^ semi-elliptical in outline convex, longitudinally arched, distinctly and equally trilobate. The axis is elevated, tapering with slightly rounded margins to a blunt and somewhat elevated termination just within the border. It is somewhat ap- pressed at the sides just above the axial furrows, bear- eleven annulations, which are angulated at the sides and posteriorly recurved over the median line. Upon the axial line each bears a strong tubercle. The pleura, are depressed below the axis, slightly flattened above ami equally deffected to the lateral and posterior margins. Each bears seven or eight annulations which are grooved by line impressed lines. The bonier is thickened, moderately and equally broad throughout its extent: it is encroached upon by the articulating ring, and slightly by the first two or three annulations. The surface is covered with minute and distinct tubercles, which are irregularly disposed upon the annulations of the axis, but are arranged in two or more rows on each angulation. A very young example, measuring 2 mm. in length and 3 mm. in width, shows nine annulations on the axis and ten on the pleurae; the margin is less thickened than in the later stages of growth, all the pleural annulations encroaching upon it. The ornamentation is also more distinct than in larger specimens. An average specimen measures 6 mm. in length and 9 mm. in width. Distribution. Upper Helderberg group. Corniferous limestone: LeRoy, Genesee county; Canandaigua, Ontario county: Williamsville, Erie county; Falls of the Ohio, Ky. Ill) PALAEONTOLOGY OF NEW YORK. Proetus stenopvge, n. sp. PLATE XXII, FIG. 27 Pygidium small, short, transverse; anterior and posterior curves equal. Axis wider than one-third the width of the shield, very convex and ele- vated, sloping to a blunt termination upon the border; composed of seven annulations, each of which, near the axial furrows, is broad, flat and impres- sed with a faint oblique line, and near the median line is slightly angulated. Pleura depressed, nearly flat; composed of four broad annulations, each of which is grooved for its entire length, making the anterior and posterior liinhs of the same strength. The annulations become obsolete upon the border, which is moderately broad, thick and rounded. Surface smooth or minutely granulose. Length 3 mm., width 5 mm. Specimens of this peculiar form of pygidium are not of common occurrence, but are of interest as representing a type of pygidium abundantly developed among the Proeti of Germany and Bohemia, as shown in such species as Proetus lavigatus, Goldfuss; P. rnmpJanatus, P. negledus, P. Loveni, Barrande., etc. Distribution. Upper Helderberg group. Corniferous limestone: Flint Creek, township of Phelps. Ontario county; North Cayuga, Province of Ontario. Proetus ovifrons, n. sp. PLATE XXII, FIGS. 31, 32. Several fragments of head-shields showing certain features in common serve to separate this form from any described species. The glabella is broadly conate, convex, longitudinally arched and closely appressed against the narrow anterior margin. The first three pairs of lateral furrows are nearly obsolete, the second and third pairs being visible only near the marginal sulcus; the fourth pair is very strong and deep, each furrow beginning opposite the center of the palpebral lobe and extend- er obliquely backward to the occipital furrow, making the basal lobes very Large, with a Length equal to one-third the length of the glabella. The occip- CRUSTACEA. Ill ital lobes are small and well defined; the occipital furrow sharp and narrow, and the occipital annulation broad and flat. The anterior border is narrow, thickened and curved upward. Surface finely tubercled. Length of the cephalon 7 mm., width between the eyes. 5.5 mm. Observations. The fragments of this species in their general outline, reflexed anterior bonier and strong basal glabellar lobes, are very similar to the same parts in Proetus rnacrocephalus, of the Hamilton group, though in the latter the glabella is less convex, more elongate and conate than in P. ovifrons. The simi- larities which exist in the cephala of these two species, and which are also observable in the pygidia of P. microgemma ami P. rnacrocephalus, may. with a more complete knowledge of these Upper Helderberg forms, ultimately render it necessary to unite these detached parts under one specific designation. Distribution. Upper Helderberg group. Corniferous limestone: In the de- composed chert. Canandaigua, Ontario county. Proetus delphinulus, n. sp. PLATE XXIII. FIGS. 1,2; iM' PLATE XXV, FIG 6 A single small, somewhat imperfect cephalon shows the following characters: Outline semi-elliptical ; border very broad, its width on the anterior limb, where it is slightly produced, equaling one-third the length of the cephalon: along the margin it is conspicuously thickened and gently reflexed ; the mar- ginal sulcus is broad and deep on the cheeks, becoming much wider on the frontal area, producing a general concavity in that part : this sulcus is bounded on its inner margin by a narrow ridge skirting the base of the cheeks. The genal angles are produced into slender, acute spines, longer than the glabella, and distinctly grooved on their upper surface by the continuation of the occipital furrow. The facial sutures converge rapidly on the frontal area. The glabella is sub-conate, and relatively small, tapering rapidly from the base to the anterior extremity, which lies just within the broad frontal 112 PALEONTOLOGY OF NEW YORK. border. The specimen is somewhat crushed across the base of the glabella, but sufficient is retained to show evidence of strong basal lobes similar to those in P. ovifrons, and above these, indications of two pairs of lateral furrows. The eyes arc elongate, relatively narrow, and are closely appressed to the glabella. Tbe single example has an axial length of 5 mm., a length to the apex of the cheek-spines of 9 mm., and a width of 7.5 mm. Distribution. Upper Helderberg group. In the decomposed Corniferous chert, a1 North Caj uga, Province of Ontario. PROiiTUS [?] PLANIMARGINATUS. PLATE XXIII. FIG. 12 Proetus planimarginatus, Meek. Proc. Acad. Nat. Sci. Phila., p. 89. 1871. atus, Meek. Palaeontology of Ohio, vol. i, p. 233 ; pi. xxiii, figs 3 a, b. is"::. Ptgidium semi-elliptical in outline: length to width as 3 to 5. Surface de- pressed-convex on the sides, elevated along the axis. Border moderately broad, Sal and sulcate near the edge. The axis, on the anterior margin, has about one-fourth the width of the shield, and tapers evenly to a blunt extremity considerably within the poste- rior margin. It bears ten distinct, and traces of two or three indistinct annulations; these are transverse over the median area, slightly angulated and inclined posteriorly toward the margins. The pleura each bear nine low, narrow annulations, separated by broad, shallow sulci, and each annulation is sulcate upon its summit for its entire length. The annulations become obsolete toward the posterior extremity, leaving the post-axial area smooth. The type specimen of the species is a smooth cast of the lower surface, and from Mr. Meek's observations upon other specimens, the dorsal surface appears to have been devoid of ornamentation. Dimensions of the original: length 10 mm., width 25 mm. CRUSTACEA. 113 Observations. The true generic position of this species must remain a mat- ter of some doubt until more complete representatives have been obtained. The pygidium lacks the expression of the caudal shield in Proetus, and is sug- gestive of that part in some species of Dalmanites, notably of D. Calypso with which it is associated. It is however tentatively left with the former genus awaiting more conclusive evidence of its character. Distribution. Upper Helderberg group. Corniferous limestone: In the upper part of the formation, Sylvania, Lucas county, Ohio. Proetus tumidus, n. sp. PLATE XXIII, FIG. 9. A probably distinct species of Proitus is indicated by fragments of the cephalon, which show a glabella having an outline somewhat as in P. folliceps, but narrower and much more conspicuous anteriorly. The surface is convex, slightly flattened above; the anterior and antero-lateral slopes abrupt, the posterior slope much less so; the occipital lobes are almost obsolete, the occipital furrows broad and elevated, the occipital ring narrow. The frontal border is broad and flat or gently sloping. Distribution. Upper Helderberg group. In the limestones at Port Colborne and North Cayuga, Province of Ontario. Proetus Haldemani. PLATE XXI, FIGS. 7-9 ; and PLATE XXIII, FIGS. 13-15. Proetnx Haldemani, Hall. Descr. New Species of Fossils, etc., p. 74. 1^'U. Proetus Haldemani, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 102. 1862. Proetus Haldemani, Hall. Illustrations of Devonian Fossils, pi. xxi, tig-. 7-9. 1876. Dechenella Haldemani, Kayser. Zeitschr. '1. deutsch. geol. Gesellseh. Jahrg. U 7, pi. xxvii. fig. 9. Proitus Haldemani, Walcott. Monog. U. S. Geol. Survey, vol. \iii: Pal. Eureka Dist., i». 210. 1884. f Dechenella Haldemani. Tschernyschew. Mem. du ComiW g6ol., vol. iii, N 14, pi. i, fig-. 9. 1887. General Form and Proportions. Outline sub-elliptical or elongate-ovate. Surface convex, distinctly and equally trilobate. Length to width as 1.7 to 1. 114 PALEONTOLOGY OF NEW YORK. Cephalon semicircular or semi-lunate in outline; border broad, flat and rounded at (she edge ; widest in front and narrowing toward the genal angles, where it is very faintly produced. Surface evenly convex. Facial Sutures normal, rapidly approximating on the frontal margin. Glabella broadly conate, constricted opposite the anterior angles of the eyes. Surface depressed-convex. Length and greatest width about equal ; tin anterior extremity scarcely reaching the marginal sulcus, the posterior margin ending abruptly at the occipital furrow. The anterior and lateral margins are bounded by shallow and inconspicuous furrows. Lateral furrows, as shown upon the cast of the lower surface, in four pairs, accompanied by the posterior accessory depressions. Of these furrows the first pair is very short and transverse, the other three pairs and the accessory pair inclined obliquely backward. The fourth pair is strong and reaches to the posterior margin, but does not open into the occipital furrow. Upon the surface of the test these lateral furrows would undoubtedly be less conspicuous, but no specimen has been observed in which the crust of the glabella is retained. Occipital lobes moderately strong ; occipital furrow narrow, impressed and scarcely widening upon the cheeks ; occipital ring moderately broad, some- what flattened and of about the same width along the posterior margin. Eyes relatively large and somewhat elevated above the surface of the gla- bella. Palpebral lobe prominent; palpebral furrow shallow and inconspicu- ous; orbital ridge well defined. Cheeks slightly depressed on the summit about the base of the orbital ridge, and rounding over the very narrow lateral area to the broad and shallow marginal sulcus. Thorax sub-rectangular, lateral margins nearly parallel, slightly approximating posteriorly; length to width as 1 to 1.5. Surface convex, sub-equally tri- lobate. Composed of ten segments. Axis evenly arched and gently tapering to the pygidium. Segments rounded and somewhat flattened, transverse or with a slight anterior curve over the axial Bine. CRUSTACEA. L15 Pleura flattened near the axis for less than one-third their width, thence deflected, in a rather abrupt curve, to the lateral margins. Segments strongly sulcate over the fulcrum, the anterior limb being sharply angulated and he- coming rapidly obsolete upon the beveled articulating surfaces. Pygidium rounded sub-triangular, slightly produced at the extremity; length to width as 1 to 1.5. Surface convex, sloping evenly to the lateral and poste- rior margins. Axis narrow, its width on the anterior margin being about one-fourth the width of the shield; longitudinally arched and slightly angulated poste- riorly along the median line; tapering evenly to an obsolete termination at the border. Composed of eleven or twelve flattened, transverse annulations. Pleura, broad and evenly rounding to the margins ; bearing from eight to eleven annulations, each being grooved by a faint impressed line, which is most distinct near the axis and toward the margins. The border is moderately broad and thickened, widening to the posterior extremity, the annulations, with the exception of the first three or four, becoming extinct upon reaching its inner margin. Surface smooth or minutely granulose. Dimensions. The only entire individual observed measures as follows : Body. Cephalon. Thorax. Pygidium. Length 20 mm. 7 mm. 7 mm. 6 mm. Width 11mm. 11mm. 10 mm. 9 mm. Observations. The specimen upon which this species was founded is a beauti- fully preserved example, which was obtained many years since from the late Professor S. S. Haldeman, of Columbia, Pa. Its locality is not known further than that it is from the south-western part of the State of Pennsylvania. It is preserved in a compact, fine-grained, chocolate-brown limestone, undoubtedly of the age of the Hamilton group of the State of New York, since isolated cephala and pygidia of the same species have been found in the Goniatite lime- stone of the Marcellus epoch in this state. It is a very distinctly defined 116 PALEONTOLOGY OF NEW YORK. species and cannot be confounded with any of the allied species of Proetus in the adjoining formations. Pygidia considerably larger than those found in New York, but agreeing in essential details with that of the type of P. Haldemani, occur in the Hamilton limestone at Long River, Michigan. The specimens of this species from the Eureka District of Nevada, described by Mr. A\ alcott (op. tit), consist of two fragmentary cephala and two pygidia, which agree in every essential feature with the type, except in the character of the frontal border of the head, which in the typical form is flat, while in these specimens it is strongly reflexed. This feature may eventually prove of specific importance. More recently certain pygidia from the west slope of the Ural Mountains have been referred to this species by Tschernyschew (Die Fauna des mittl. und ober. Devon am West-abhange des Urals, he. tit.). So far as may be judged from the figures alone, these appear to be considerably shorter and more elliptical, with a relatively wider and stouter axis than in the type specimen. Distribution. Hamilton group. In the Goniatite limestone of the Marcellus epoch: Cherry Valley. Otsego county; Manlius, Onondaga county. In the Hamilton limestones : Long River, Michigan. In the Devonian (Hamilton ?) limestone in Pennsylvania, and in the Eureka District, Nevada, Proetus macrocephalus. PLATE XXI, FIGS. 10-21; and PLATE XXIII, FIGS. 30, 31. Proetus macrocepJialus, Mall. Deser. New Species of Fossils, etc., p. 77. 1861. lug, Halt,. Fift th Rept. N. Y. State Cab. Nat. Hist., p. 105. 1S62. /,( '•"'■'■'•' ■■■'" ■-■■ vslt. a.. Halt,. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 107. 1862. . Hall. Illustrations of Devonian Fossils, pi. xxi, figs. 10-21. 1876. Genebal Form and Proportions. Outline elliptical. Surface depressed-convex, distinctly and sub-equally trilobate. Length to width as 1.5 to 1. Cephai.on sub-semicircular or lunate, margin slightly thickened and reflexed, produced at the genal angles into thin acute spines. Surface very convex in normally preserved specimens; depressed in the usual state of preservation. Length to width as 1 to 2. CRUSTACEA. 117 Facial Sutures normal. Glabella sub-conate, sides broadly tapering to the anterior extremity, where it is closely appressed upon the narrow, reflexed margin. Width three- fourths the length. Surface convex, anterior slope normally abrupl or vertical, curving posteriorly and becoming horizontal at the occipital furrow. Under normal preservation only a single pair of lateral furrows is visible. These are the fourth or basal furrows and are very strong and deep, taking their origin nearly opposite the anterior angle of the eye and extending to the occipital furrow, thus forming two strong conspicuous lobes. Upon casts of the lower surface, and in extremely rare instances upon the dorsal surface. there is evidence of the first, second and third pairs of furrows, with faint indications of the accessory furrows. Occipital lobes prominent : occipital furrow narrow, broadly hi furcating about the occipital lobes, and becoming deeply impressed and broadened upon the cheeks: occipital ring broad and posteriorly convex, narrowing upon the cheeks. Eyes not large, lunate; palpebral lobe inconspicuous; palpebral sulcus nar- row and deep. Cheeks deeply grooved about the orbit of the eye, and abruptly depressed to the broad marginal sulcus. Thorax sub-rectangular; surface convex and equally trilobate; length to width as 1 to 1.8; composed of ten segments which are arched upon the axis and considerably elevated above the pleurae, obliquely flattened and transverse. The pleura, are flattened for less than one-half their width and abruptly deflected to the margin: segments sulcate, anterior and posterior limbs nearly equal, the former becoming abruptly obsolete at the fulcrum. Pygidium large, semi-elliptical, convex: length to width as 2 to 3. Axis having less than one-third the width of the shield upon the anterior margin, and tapering to a blunt termination within the border. Annulations thirteen or fourteen, with an anterior bend near the mar-ins, and a broad curve over the median line; in most individuals, the annulations are slightly L18 PALMONTOLOGY OF NEW YORK. angulated along the axial line, each sometimes hearing a moderately strong tubercle. Pleura depressed in a more or less abrupt curve to the margin, bearing eleven or twelve flattened annulations, which are separated by moderately strong sulci. Each annulation is faintly grooved by a fine impressed line, which is sometimes almost or quite obsolete. Border broad, becoming exca- vate and slightly reflexed posteriorly; all the annulations except two becom- ing obsolete upon reaching it. Doublure broad, reaching to the termination of the axis. Surface Ornamentation. The cephalon is covered with low tubercles which become obsolete upon the anterior portion of the glabella and the depressed areas of the cheeks. Upon the thorax and pygidium each segment and annulation is ornamented with granules; these upon the latter sometimes appear to be arranged in two rows, one upon each limb of the pleural annu- lations. In rare examples a row of small tubercles is noticeable along the axial line on both thorax and pygidium, beginning with a faint tubercle upon I he occipital ring, the next being at the third or fourth segment, thence backward becoming stronger toward the apex of the axis. Dimensions. An average individual measures : Body. Cephalon. Thorax. Pygidium. Length 37 mm. 13 mm. 11mm. 13 mm. Width 24 mm. 24 mm. 22 mm. 21mm. The largesl entire individual observed has a length of 60 mm. and a width of 40 mm. Observations. Entire individuals of Proetus macrocephalus are of rare occur- rence, and the crust is so delicate and tenuous that when the parts are in juxtaposition, it is usually broken away. The symphysis along the facial sutures appears to have been very free, for the movable cheeks are usually de- tached, and of several hundred specimens of the species which have passed under observation but a single example retains all the parts. CRUSTACEA. Ill) The species occurs without variation except in the occasional presence of the axial row of tubercles, and this peculiarity was noticed in the original descrip- tion of the species (Fifteenth Kept, N. Y. State Cab. Nat. Hist., he. tit.), the variation being designated as P. macrocephalus, var. a. It appears, however, on closer examination, that this feature is not connected with variations in other respects, and individuals are found showing all intermediate stages between those with and those without tubercles. P. macrocephalus affords many points of close similarity to P. curvimarginatus, the general proportions of the two species and many of the details being quite identical. Differences, however, exist in the following respects : In the former the border is not so broad, so deeply excavate or so strongly reilected ; the glabella is more broadly conate, and its lateral furrows much less conspicuous ; the genal spines are shorter and stouter; the pygidium more elongate and more distinctly flattened upon the pleurae. Distribution. Hamilton group. In the limestone layer of the Marcellus shales: Orleans, Ontario county; in the Hamilton shales of the central and western counties; Canandaigua Lake, at Menteth\s, Tichenor's and Foster's Points; Canandaigua, Bristol and Hopewell, Ontario county; Bellona, Yates county; Jaycox's Run, near Geneseo, and Moscow, Livingston county ; Bethany, Genesee county; Eighteen-mile Creek, Erie county ; in the Tully limestone, below Lodi Landing, Seneca Lake, and Borodino, Onondaga county. Proetus Rowi. plate xxi, figs. 'j 6,21 26; and plate xxiii, figs. 20-29. Calyniene Rowii, Green. Amer. Jouvn. Science and Ails, vol. xxxiii. p. 406. 1838. Proetus Bowii, Hall. Descr. New S] ies of Fossils, etc., p. 75. 1861. Proetus RovAi, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. Id::. 1862. Proetus Sxnmi, Hall. Illustrations of Devonian Fossils, pi. xxi, figs 2-6. 1876. General Form and Proportions. Body ovate or elongate-elliptical in outline. Surface depressed'-convex, sub-equally trilobate. Axial length one-half greater than the width at the base of the cephalon. Cephalon semi-elliptical to semicircular in outline, width about twice the length. Border broad and Hat; at the angles of the cheeks produced into 120 PALEONTOLOGY OF NEW YORK. spines which reach as far as the fourth segment of the thorax. Posterior margin transverse. Surface moderately convex. Facial Sutures normal, approximating on the frontal margin. Glabella simple, elongate, sub-conate, sloping to a broadly rounded anterior extremity, which encroaches upon the frontal border. Length one-third -nater than the width. Surface convex, longitudinally arched when nor- mally preserved. There are usually no traces of lateral furrows, but a single individual in which the crust is slightly separated from the rock and has .me translucent, shows evidence of three oblique lines, apparently the second, third and fourth lateral furrows; the first pair being obsolete, and the fourth extending only part way across the glabella. Occipital lobes con- spicuous, transverse; occipital furrow narrow and sharply impressed, scarcely widening upon the cheeks; occipital ring broad, arched and somewhat flat- tened, narrowing slightly to the genal angles. Eyes approximate, large, lunate, not elevated above the surface of the glabella; extending from the occipital lobes two-thirds the length of the glabella. Visual surface quite convex, particularly in young individuals. Palpebral lobe moderately large, sloping inward to the palpebral sulcus, which is sharply incised. Cheeks relatively narrow on account of the size of the eyes. Conspicu- ously grooved or depressed about the orbital ridge, and rounding more or less abruptly to the margin. The border is unusually wide and carries two paral- lel grooves, the outer of which is narrow and marginal, producing a beveled edge; the inner broad and shallow, becoming flat in old individuals. On the posterior border the margin is also beveled, and the genal spines are strongly ridged by the meeting of these beveled edges. Thorax transversely sub-rectangular, lateral margins slightly rounding and approximating posteriorly. Length to width as 2 to 3. Surface convex and strongly trilobate. Composed of ten segments. Axis arched, having more than one-third the width of the thorax; widest at the third or fourth segment, and tapering with slightly rounding margins CRUSTACEA. 121 to the pygidium. Segments flat, transverse, or with a gentle forward curve over the axial line. Pleura flattened for one-half their width, and thence depressed in a more or less abrupt curve to the margins. Each segmenl is sulcate, the anterior limb being sharply angulated at the fulcrum and becoming rapidly obsolete upon the lateral slope. Pygidium sub-semicircular or sub-semi-elliptical in outline, faintly and broadly emarginate behind; length to width as 1 to 2 ; surface depressed-convex. Axis broad on the anterior margin ; width equal to one-third the width of the shield ; arched and sloping to a termination within the posterior border, a low ridge connecting the apex of the axis with the margin; composed of nine or ten low, flattened annulations, which have a forward inclination for about one-fourth their width from the axial margins and pass over the median area in a gentle posterior curve. Pleura gently depressed, bearing six annulations with indications of a seventh, which are low, flat and faintly sulcate, becoming obsolete at or near the margin. The border is conspicuously thickened and moderately broad. Hypostoma with a very convex centrum, sides abruptly depressed and margins flattened. Widest on the anterior margin ; lateral margins incurved ; poste- rior area extended ; posterior sulcus deep ; postero-lateral sulcus conspicuous, elevated. Length equal to the width on the anterior margin. Surface Ornamentation. Upon the cephalon the surface of the glabella is covered with faint, obsolete pustules, and most individuals show indications of a large but indistinct tubercle in the axial line at the base of the glabella. The summit of the cheeks beneath the orbital ridges is covered with obscure, elongate or radiating tubercles, interspersed with simple pustules. Upon the thorax and pygidium the posterior edge of each segment and annulation bears a single row of sharply defined granulations; sometimes accompanied by finer and irregularly scattered granules. There are usually indications of a row of faint axial tubercles beginning at the occipital ring, omitting the first six thoracic segments, thence recurring and extending to the second or third 122 PALEONTOLOGY OF NEW YORK. annulation of the pygidium. The surface of the hypostoma is punctate and covered with strong, concentric, lamellose markings. Dimensions. An average individual affords the following measurement: Body. Cephalon. Thorax. Pygidium. Length 36 mm. 14 mm. 12 mm. 10 mm. Width 22 mm. 22 mm. 20 mm. 18 mm. The smallest entire specimen observed has a length of 12 mm., and a width of 9 mm., and the largest specimen, in which the parts are somewhat detached, was an individual measuring 62 mm. in length. Observations., Proitus Rowi is one of the rarer species of the Hamilton fauna. The fossil was first brought to public notice by Mr. Le Row, in the Poughkeepsie Telegraph of November 22, 1837, and was described by Green in the following year, as cited. The original was from the sandy shales of the group in Otsego county. In one locality only has it proven to be an abundant fossil in good preservation, namely, on Seaver's creek in the township of Canandaigua, Ontario county, in the shales and limestone immediately overlying the Marcellus shales. Careful comparison of this species with Proi'lus clarus, Hall, of the Upper Heidelberg limestone, shows a very close similarity in the broader features and in the general expression of the animal. While the former may be regarded as the Hamilton representative or descendant of the latter, there are certain asso- ciate! details which will serve to distinguish the species. Proitus Rowi has larger eyes, flatter thoracic segments, a less abruptly tapering axis and a larger num- ber of annulations upon the pygidium, and a peculiar ornamentation upon the cheeks, thorax and pygidium, which has not been noticed in Proitus clarus. Proitus marginalis. Calymem marginalis, Conrad. Ann. Rept. Palaeontology of N. Y., p. 66. 1S39. Proitus marginalis ('.). Mall. Descr. New Species of Fossils, etc., p. 76. 1861. Proitus marginalis (?), Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 104. 1862. Proitus marginalis (1), Hall. Illustrations of Devonian Fossils, pi. xxi, figs. 24-28. 1S76. The original of Mr. Conrad's Calymene marginalis was a cephalon described by him in the following terms {loc. cil.) : CRUSTACEA. 123 "C. marginalis, Buckler, with a broad margin : eyes large, semi-oval; middle lobe entire, convex, smooth abdomen ' '■'■Locality. Near Ithaca, in a boulder. This has a much less prominent front than the Rowi, a deeper groove between the eye and middle lobe, and the tubercle which nearly joins the lower angle of tin- eye is much smaller." It was subsequently ascertained that the boulder referred to by -Mr. Conrad, was a mass of the Tully limestone, which had been transported many miles south of the outcrop of that formation. For this reason the species of Proetus which has been frequently found in the outcrops of this rock upon Seneca and Cayuga Lakes, in Onondaga county, and elsewhere, was regarded in the published de- scriptions of 1861 and 18G2 (rid. loc), as probably specifically identical with Mr. Conrad's original. This reference was without doubt correct, but the more com- plete material illustrating this fossil and its allies in adjoining formations, which has accumulated since the publication of these descriptions, has afforded eon- elusive evidence that P. marginalis, Conrad, is identical in every specific detail with P. Rowi, Green. The points of difference in these forms, as stated in the description quoted above, depend solely upon the condition of preservation of the specimens. As the individuals of P. marginalis occurring in the State of New York are pre- served in limestone, the surface has more nearly retained its normal rotundity, and the glabella is less extended anteriorly than in the usually somewhat flat- tened examples of P. Rowi from the Hamilton shales. The specimens from the Tully limestone show that the glabella encroaehes slightly upon the frontal margin, as in normal examples of P. Rowi. The depth of the groove between the eye and the glabella depends entirely upon the degree of flattening of the specimen ; and the size of the occipital lobe varies with the absence or retention of the crust. After a careful examination of all the representatives of P. marginalis at hand, it seems impossible to associate any characteristics by which it can be distinguished as even a variety of P. Rowi, and the foregoing description of the latter species will apply in every respect to Mr. Conrad's P. marginalis. This fossil occurs in the Tully limestone, in intimate association with Pha- [24 PALAEONTOLOGY OF NEW YORK. cops rana and Dalmanites Boothi, var. Calliteles, as does also P. Rnwi, in the basal layers of the Hamilton shales. The name Proehts marginalis, Conrad, as far as it has included the forms of Pro, his occurring in the Tally limestone, may therefore be regarded as synonymous with P. Rowi, Green. Distribution. Hamilton group. In the Hamilton shales: On Seaver's Creek, Township of Canandaigua, Ontario county; York, Livingston county; Ham- burgh and Eighteen-mile creek, Erie county; Vly creek and elsewhere, Otsego countv. In the sandy shales of Schoharie county. In the Tully limestone : Below Lodi Landing, Seneca lake; at Weston's quarry, near Spofford Corners, Split Rock, near Borodino, and Tully, Onondaga county; Moravia, Cayuga county, and Cuyler, Cortland county. Proetus jejunus, n. sp. PLATE XXV, FIG. 7. l'viiiuiUM moderately large, the posterior outline being the arc of a circle. . Axis elevated, relatively narrow, having one-fourth the width of the shield on the anterior margin ; tapering rapidly to an obtuse apex distant from the posterior extremity. The apex is slightly elevated, a low, depressed ridge connecting it with the posterior border. Ten annulations can be counted, all of which show a retral bend over the axial line, and each bears a con- spicuous central node. The pleura are relatively broad and slope with a gentle curve outward to the narrow border. There are eight annulations, exclusive of the articulat- ing ring, and on the cast of the lower surface they appear to have been distinctly sulcate. Border smooth except near the antero-lateral angles, where it is encroached upon by the annulations. dimensions. Length 13 mm., width 21 mm. Observations. This species is represented by a single pygidium from which the crust has been largely removed, hut the specimen is sufficient to show that CRUSTACEA. 125 it represents a definite specific variation from other tonus included under this genus. Its distinctive characters are the broad, explanate pleura? and the axial row of nodes. The general proportions of the pygidium are similar to those of Proetus Rowi, P. darns and P. Prouti, but from all these it differs in its axial row of nodes and more conspicuously sulcate annulations. From P. macrocephalus, which often bears nodes upon the axis of the pygidium, it varies in the more numerous annulations and greater proportional length of the former. Distribution. Hamilton group. In the sandy shales, Albany county. Proetus Phocion. PLATE XXV, FIGS. 9, 10. Proitu.? Phocion. Billijc.s. Pakeozoic Fossils of Canada, vol. ii.'y.l. 1. p. 63, fig\ 31. 1S74. General Form and Proportions. One of the type specimens, which is a cast of the lower surface of an entire extended individual, indicates a body rela- tively broad and short, and more depressed upon the axis and pleurse than P. Rowi or P. Conradi. Cephalon This part of the body is closely similar to that of P. Rowi and P. angustifrons. The border is moderately broad, slightly convex on its proximal edge, becoming gently concave outwardly as in P. Roici, but pro- duced into shorter cheek-spines. The cheek is elevated and distinctly ridged at about half the distance from the border to the base of the eye, and is broadly flattened on the upper surface. The glabella has much the same proportions as in P. angustifrons, and shows indications of three pairs of lateral glabellar furrows. The occipital ring bears a central tubercle, which is situated on the upper surface as in P. angustifrans, and not on the posterior margin as in P. Rowi. The basal lobes in the occipital furrow are larger, but not so distinctly defined, and the eye is smaller than in P. Rowi. The Thorax bears no feature of distinctive value except the general smooth- ness of the test, and the rounded posterior margins of the axial segments. L26 PALEONTOLOGY OF NEW YORK. The Ptgidiom is like that of P. Roivi, the axis bearing the same number of annu- lations, nine or ten, but scarcely so wide or so strongly arched as in that species ; the pleura are more flattened, the ribs, of which four or five may be counted, being very faint, becoming obsolescent. The border is distinctly thickened. Dimensions. The cast of the lower surface of the entire individual meas- ures as follows : Body Cephalon. Thorax. Pygidium. Length — 35 mm. 12.5 mm. 13.5 mm. 9 mm. Width. 24 mm. 24 mm. 21mm. 19 mm. Observations. Of all the American Proiti which follow the type of structure exemplified in P. Rowi, Green, this species is much the broadest and stoutest, although it is closely allied in many details to several members of the group. It may be important to note that this broad form has been found only in the easternmost outcrops of the Devonian formations; while the narrowest and most slender member of the group is from the far west (Eureka District, Nevada). Distribution. In the upper limestones and sandstones of Indian Cove, Gaspe, Province of Quebec. Proetus Prouti. PLATE XXIII, FIGS. 16-18. Pi tins Prouti, Shumard. Trans. Sf. Louis Acad, of Sci., vol. ii. No. 1, p. 110. 1863. Proetus Davenportensis, Barbis. Proo. Davenport Acad. Nat. Sci., vol. ii, p. 287; pi. xi, fig. 8, and pi. xi revised, fig. 8. 1878. General Form and Proportions. Body elliptical or sub-ovate in outline; length to width as 3 to 2. Surface convex, scarcely elevated, and conspicuously trilobate. Cephalon sub-semicircular, faintly produced at the anterior extremity. Bor- der broad and prominent, deeply grooved in front and recurved at the edge, becoming Hatter at the sides, the sulcus more shallow and narrower and accompanied by a less conspicuous sulcus nearer the cheek. At the genal CRUSTACEA. L27 angles the margin is produced into long, rounded spines which reach to the seventh segment of the thorax. Posterior margin nearly straight. Facial Sutures normal, curving sharply forward on the anterior margin. Glabella elongate-sub-conate, surface depressed-convex; length about one- fourth greater than the width. The narrow anterior extremity encroaches slightly upon the frontal border. Lateral furrows in lour pairs, accom- panied by the posterior accessory furrows. These furrows are all linear and in the specimens at hand are quite faint upon the surface, being made more conspicuous by the somewhat translucent test. Occipital lobes promi- nent, transversely sub-pyriform ; occipital furrownarrow and sharply impressed; occipital ring broad, somewhat flattened above, and strongly arched. Eyes moderately large, lunate ; orbital ridge depressed and strongly sul- cate at its base. Palpebral lobe large and closely appressed against the glabella; palpebral sulcus narrow and elevated. Cheeks depressed at the summit and rounding more or less abruptly to the posterior and lateral margins. Thorax sub-quadrate, about one-third longer than wide; lateral margins round- ing to the pygidium. Surface sub-equally trilobate. Axis convex and arched, having about one-third the width of the thorax. attaining its greatest width at the fourth segment, whence it tapers regularly to the pygidium. Segments narrow and somewhat flattened. Pleura laterally depressed at about one-third their width from the axis. The segments are conspicuously sulcate, the anterior ridge becoming rapidly obsolete beyond the fulcrum. Pygidium sub-semicircular in outline, faintly emarginate at the posterior ex- tremity ; anterior margin with a slight forward curve ; width equal to twice the length. The border is broad and conspicuous, flattened anteriorly, thickened and slightly sulcate behind. Axis rather narrow, having less than one-third the width of the shield on the anterior margin, tapering rapidly to a blunt and elevated apex within the posterior border. It is composed of from eight to ten annulations which 128 PALEONTOLOGY OF NEW YORK. have a forward Bend near the axial furrows and a slightly retral curve over the median line. Pleura evenly convex and bearing from six to eight annulations, each of which is grooved by a finely impressed line. All the annulations become extinct upon reaching the border. Surface Ornamentation. Upon the cephalon and thorax the test is covered with faint, nearly obsolete pustules or granulations, which seem to be want- ing upon the pygidium, except at the posterior edges of the axial annula- tions. The last four or five segments of the thorax each bear a strong tubercle in the axial line, as in Proitus Rowi. A faint axial tubercle is also visible upon the occipital ring. Dimensions. An entire individual of normal proportions measures : Body. Cephalon. Thorax. Pygidium. Length 37 mm. 14 mm. 13 mm. 10 mm. Width 26 mm. 26 mm. 20 mm. 19 mm. Observations. The Proitus Davenportensis of Barris, appears to be identical with Shumard's type, and the description here given is from Mr. Barris' original specimens, which he has kindly loaned for the purpose. Proitus Prouti may be regarded as a western representative of the type of Prortus, exemplified by the New York species, P. angustifrons, P. clarus and P. Rowi. With the last named species it has many points of close similarity, both in general contour and in details. It will be found, however, to differ in the following particulars, which, taken together, prove of specific value: the cephalic border is broader and more conspicuously grooved; the genal spines very much longer; the axis, both upon the thorax and pygidium, narrower; the pygidium more evenly convex, and with a more conspicuous border. Distribution. Hamilton group. In the fawn-colored limestone, near Daven- port, Iowa. CRUSTACEA. 129 Proetos Nevad/E, n. sp. PLATE XXIII, FIG. 19 ProStus marginalis, Walcott. MonogT. V. S. CJeol. Surv., vol. viii : Pal. Eureka Dist.. ]>. 210. 1884 The specimen identified by Mr. Walcott as Proitus marginalis, Conrad, in the work above cited, is a well-preserved and nearly entire individual, which ex- hibits points both of relationship and difference with the various representatives of the group of Proifus typified by P. Rowi, viz. : P. angustifrons, clarus, mar- ginalis (= Rowi) and Prouti. All these species are established upon differences which are of themselves slight but which nevertheless appear persistent. To any of these species, as here described, it becomes impossible to admit the Nevada form, as it differs from each member of this group in as many respects as those species differ from one another. It therefore seems neces- sary to regard it as having a distinct specific value founded upon characters which may be best expressed by a comparison with each of the species above mentioned. With P. angustifrons it agrees (a) in the character of the frontal border, which is convex near the marginal sulcus and slopes evenly to the edge, becoming faintly concave on the anterior limb ; (b) in the relatively narrow glabella, tan- gential upon the frontal border (in the type specimen the glabella has been slightly compressed laterally and thus appears somewhat narrower and more convex than is normal) ; (c) in the number of annulations upon the pygidium. It differs from this species in (a) the narrower and more elongate body; (b) the much smaller eyes ; (c) the broader, more elevated and convex cheeks ; (d) the longer and more slender genal spines ; (e) the narrower and more elevated pygidial axis. With P. clarus it agrees in (a) the character of the frontal margin ; ()>) the length of the genal spines; (c) the form, contour and annulations of the pygi- dium. It differs from this species in (a) the much narrower and more regularly elliptical body ; (b) the much narrower glabella ; (c) the smaller eyes ; (d) the narrower, more arched and more slowly tapering thoracic axis; (e) the narrower pygidial axis. 130 PALEONTOLOGY OF NEW YORK. With P. Row? (including P. marginalis, Conrad), it agrees in (a) the more elongate and slender form ; (h) the character of the ornamentation of the the cheeks; (c) the relatively narrow axis of the thorax; (d) the convex pygi- dial border. It differs from this species in (a) the narrow glabella not encroach- ing upon the frontal border; (b) the much smaller eyes; (c) the broader, more elevated cheeks; (d) the larger cheek-spines; (e) the convex frontal border; (f) the narrower pygidial axis; (g) the absence of the low elevation connecting the apex of the axis with the posterior border. With P. Prouti it agrees in the general features common to all these species, but differs in (a) the character of the frontal border ; (b) the shorter cheek- spines; (c) the tangential glabella; (d) the smaller eyes; (e) the narrower pygidium, with fewer annulations. The ornamentation in P. Nevada:, consists of fine almost obsolete granula- tions. The crust of the thorax is broken in such a manner as not to show whether there existed an axial row of strong tubercles as in P. Rowi and P. Prouti. These details of difference in all these species cannot be satisfactorily repre- sented in life-size drawings. Dependence must therefore be placed upon the descriptions in establishing the limitations accurately. Distribution. "Lower horizon of the Devonian limestone; Comb's Peak, Eureka District, Nevada." (Walcott, op. cit.) Proetus occidens. PLATE XXI, FIGS. 22, 23. Proetus occidens, Hall. Descriptions New Species of Fossils, etc., p. SO. 1861. Proetns occidais, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 108. 1862. Pro, tux oceidens, Hall. Illustrations of Devonian Fossils, pi. xxi, figs. 22, 23. 1876. This species, so far as known, is represented by only two somewhat imper- fectly preserved Pvgidia. Their outline is semi-elliptical ; length to width as 3 to 4 ; surface depressed-convex. The axis has a little less than one-third the width of the shield on the anterior margin, is moderately convex and tapers evenly to an obtuse apex which lies just within the conspicuous marginal CRUSTACEA. 131 border. It bears about twelve transverse annulations. The lateral slopes are gentle and bear nine or ten flattened annulations, each of which appears to be faintly sulcate. Surface minutely granulose. The larger of the two speci- mens measures 18 mm. in length ami 23 mm. in width : the smaller 14 mm. in length and IS mm. in width. This species has proportions similar to those of Pro tits macrocephalus, but has fewer annulations and lacks the conspicuous ornamentation of that species. It is not closely comparable with anv >>{' the species here described. Distribution. Hamilton group. New Buffalo, Iowa. Proktus(?) longicaudus. TLATE XX, FIGS. 32-34. Proetus longicaudus, Hall. Fifteenth Rept N. Y. State Cab. Nat. Hist., p. 108, pi. x. figs. 7 '.'. 1862. Pnul'is longicaudus, Hall. Illustrations of Devonian Fossils, pi. xx. figs. 32-34. l^T'i. Proetus longicaudus, H. S. Williams. Amer. Journ. Science, vol. xxi, 3d Ser., p. 156. 1881. General Form and Proportions. Body elongate-ovate, tapering, with margins rounding to the posterior extremity. Cephalon broadly semi-elliptical, transversely very convex. Border wide and thick, produced into short spines at the genal angles. Glabella sub-ovoid, slightly constricted opposite the anterior angles of the eyes, and somewhat abruptly rounded in front. First lateral furrows faint and very short ; second and third pairs gently curving backward, extending nearly two-thirds the distance across the glabella; fourth pair of furrows conspicuous, passing from near the middle of the palpebral lobe to the occipital furrow, and forming two large sub-pyriform basal lobes, each of which reaches about one-third the distance across the base of the glabella. Occipital lobes wanting ; occipital ring broad and flattened above, becoming narrower on the cheeks. Cheeks broadly marginate. Eyes sub-reniform, moderately large and closely appressed upon the glabella. Thorax composed of nine segments. 132 PALEONTOLOGY OF NEW YORK. Axis very prominent, semi-cylindrical. Pleura' flat for about one-half their width, thence sloping gently to the Pygididm very elongate-triangular, the length being equal to the width. The axis tapers to an obtuse termination considerably within the scarcely thickened border; composed of twenty-two annulations, which are vertical on the sides, but have a gentle anterior curve toward their summit. Pleura flat near the axis, thence curving somewhat abruptly outward and downward ; bearing twelve annulations, which terminate in a broad, sloping 1> order abruptly recurved at the edge. Surface finely granulose. Observations. There exists a great deal of doubt both as to the generic status and the geological age of this species. The original and type specimen was presented many years ago by the Rev. Mr. Nash, of Des Moines, Iowa, together with specimens of Phacops rana, and was said to have been found in association with the latter at some point to the north-east of that place. This was the only specimen of the species known until certain others were described by Mr. H. S. Williams (loc. cit.) from a blue limestone near Madison, Greenwood county, Kansas, and he has suggested that these may have been derived from rocks not older than the Carboniferous. Mr. Williams' specimens were obtained from Mr. Edwin Walters, of Hickman, formerly of Madison, Kansas, who, in response to inquiries, writes that he has found this species in association with Phacops bufo {rana). Admitting its association with this well-known and characteristic fossil, its geological age would appear to be that of the Hamilton group. On the other hand the species, in many important structural features, is more closely related to the Carboniferous Phillipsicc than to typical forms of Proetus. The possession of but nine thoracic segments, which appears to be a normal feature of the species at maturity, is known in but one other species of Proitus, viz., P. sculpius, Barrande, from the etage G. For the genus Phillipsia this is the normal number. Moreover, the oval, slightly constricted glabella, CRUSTACEA. 133 the reniform eyes', the absence of occipital lobes, the great length of the pygi- dium and the number of its annulatioris are all Phillipsioid characters. The species may ultimately prove to be a Carboniferous fossil, hut any satis- factory determination of its age must await the acquisition of more complete material. Proetus Missouri ensis. PLATE XXIII, PIG 32. I Missowriensis, Shumard. Geol. Rept. Missouri, p. 196, pi. B, fig. 13. 1855. Proetus auriculatus. Hall. Descr. New Species of Fossils, etc., p. 79 1861. Proetus auriculatus, Hall. Fifteenth Rept, N. V. State Cab. Nat. Hist., p. 107. 1862 Phillipsia Shumardi, Herrick. Bull. Sci. Lab. Denison Univ., vol. ii. pt. 1, pp. 58, 69, pi. vii, fig. 1 I. 1887. This species is noticed here in order to call attention to its correct determina- tion and its proper synonymy. The original of Mr. Shumard's Proetus Missouri- ensis, described from the Lithographic limestone of Missouri, formerly regarded as of Upper Devonian age, is apparently identical with the detached cephala and pygidia from the Waverly sandstones of Licking county, Ohio, which were described in 18G1 under the name Proitus auriculatus, Hall. Recently an en- tire individual of the species from Licking county, Ohio, has been described by Herrick (he. tit.), under the term Phillipsia Shumardi. The change of name proposed by this author arises from the consideration that if the fossil belongs to the genus Phillipsia, the designation Phillipsia Missouriensis would be inad- missible as this name had been used by Shumard for a species from the coal measures at Lexington, Missouri, described in 1858, (Transactions St. Louis Academy of Science). Without entering into a discussion upon the right of priority under these circumstances to the specific term Missouriensis, the evidence, afforded by the entire specimen of the species, points distinctly to the fact that the genus to which it belongs is Proitus and not Phillipsia. The form of the glabella is in some respects similar to that of certain species of Phillipsia, being somewhat expanded anteriorly, the fourth lateral furrows strong and reaching to the occipital furrow, the third and second short and the first obsolete. Such variations frequently occur within the limits of the genus Proitus (P. canaliculatus, P. granulatus, P. crassimarginatus). The occipital lobes, 134 PALEONTOLOGY OF NEW YORK. which arc well developed in this species, are either obsolete or obsolescent in Phillipsia. The ten thoracic segments, however, determine its generic relations and exclude ii from the genus Phillipsia, while the relatively short pygidium is more strongly Proetoid than Phillipsioid. PHAETHONIDES, Angelin. 1878. Phaethonides arenicolus, n. sp. PLATE XXV, FIGS. 12, 13. Pygidium relatively short, broadly sub-elliptical in outline ; length equal to one- half the width. Axis elevated, comparatively narrow, having less than one-third the width of the shield on the anterior margin ; tapering to a blunt extremity consid- erably within the margin. Characterized by transverse annulations, the number of which cannot be distinctly made out, apparently from five to seven. Pleura broad, curving rapidly to the margins; bearing five annulations, with traces of a sixth, all of which are strongly sulcate, the posterior limb being much the wider, and the anterior ridge becoming extinct upon the lateral slope. Each annulation terminates upon the margin in a short, stout spinule, projecting horizontally, and the post-axial margin also bears two of these processes, making in all fourteen in the marginal fimbria. Close upon the margins of the lateral slopes are also bases of spinules equally stout, and there appears to have been a row of small tubercles further inward on the posterior limb of each annulation. This pygidium appears to be constructed on the same plan as that of Vha< thonides gemmtzus, of the Hamilton group, but the number of annulations is somewhat less, and the surface not so strongly tubercled. The single specimen from the Schoharie grit has a length of 3 mm., and a width of 6 mm. Distribution. Upper Helderberg group. Schoharie grit: Schoharie county. A specimen bearing similar characters has also been found in the decomposed Corniferous chert at North Cayuga, Province of Ontario. CRUSTACEA. 135 Phakthonides VARICELLA, 11. sp. PLATE XXIV, FIGS. '.'0-31. Cephalox. Intra-sutural portion only observed. Outline sub-circular. Frontal area broad, concave, strongly recurved at the margin. Margin slightl} thickened by doublure, elevated, reaching or exceeding the height of the glabella. Palpebral lobes conspicuous. Facial Sutures normal. Glabella elongate-ovate or pyriform, bounded by a low sulcus; convex, slightly flattened above. Basal lobes strong; baso-lateral furrows broad and deep; antero-lateral impressions duplicate, very faint upon the crust but apparent upon the lower surface. Thorax not observed. Ptgidium broad, the outline being the arc of a circle whose center is the middle of the first annulation. Axis elevated, relatively narrow and longitudinally arched, abruptly ter- minating before reaching the posterior border; composed of eleven or twelve transverse annulations. Pleura broad, depressed-convex, flattened at the margin, which is strongl} thickened bv doublure. Pleural annulations eight, six of which are silicate and double. The cast of the lower surface, which serves the purposes of description, shows the last two annulations more distinctly than they would probably appear upon the upper surface of the test. Surface of the cephalon ornamented by tubercles, which are scattered over the glabella, and are stronger upon the adjoining frontal and lateral areas. Upon the recurved marginal area the ornamentation changes to strong, abun- dant punctae, which become finer toward the margin itself. On casts of the lower surface this punctate structure is to a large degree lost. The pygidium bears an axial row of bead-like tubercles with two less conspicuous rows on each side. The pleura? show traces of three or four rows of tubercles, which become obsolete toward the posterior extremity. 136 PALEONTOLOGY OF NEW YORK. Dimensions. An average cephalon measures 6 mm. in length and 6 mm. in width; the pygidium 8 mm. in length and 10 mm. in width. Observations. In the outline and contour of the cephalon, Phaithonides vari- cella approaches Cyphaspis ornata, of the Hamilton group. Its more elevated and sharply recurved frontal margin, and the absence of the peculiar marginal ornamentation of that species, will serve as distinguishing characters of the head. The species is thus far represented by three specimens, two imperfect cephala and a single pygidium. Of these, one head and the pygidium occur in juxtaposition, so that little doubt remains of their specific identity. Distribution. Upper Helderberg group. Corniferous limestone: In the boulders of decomposed chert, Canandaigua, Ontario county. PHAETHONIDES GEMM2EUS, 11. Sp. PLATE XXIV, FIGS. 32-36. Cephalon unknown. Two detached thoraces have been found, one in close association with a pygidium, and each of them shows seven segments. It is, however, probable that some of the segments have been lost. Thorax sub-quadrate, margins nearly parallel. Axis strongly arched and very broad, being nearly one-half the width of the body on the anterior margin; width increasing backward for a short distance and thence tapering rapidly toward the pygidium. Each segment is very narrow, elevated upon the anterior margin, grooved and depressed behind. Pleura convex for about one-third their width, thence abruptly depressed to the margins ; sulcate and strongly beveled for two-thirds their length. The axis bears from three to five longitudinal rows of small pustules, one ol which is in the axial line, and the pleural bear each three or four similar rows. The articulating grooves of the axis are punctate. Pygidium. Outline sub-semicircular, anterior margin curved backward at the anterolateral angles. Surface sharply elevated along the median line, de- pressed-convex on the lateral portions. CRUSTACEA. L37 Axis convex, elevated, evenly tapering to an abrupt termination distant from the posterior margin; width on the anterior margin about one-third the width of the shield; bearing from eight to twelve narrow annulations, which have a slight retral bend along the axial line and appear to be angu- lated by the five longitudinal rows of strong tubercles. Of these rows the middle one is much the strongest. Upon the elevated termination of the axis are a number of small, irregularly scattered pustule-. Pleurce gently convex for about one-half their width, and depressed upon the broad, flattened border; bearing eight annulations, which are grooved for their entire length, making the anterior limb of each strong and the posterior limb inconspicuous. Each annulation bears upon the anterior limb four, five or six strong sub-spiniform tubercles, of which those upon the margin are much the strongest and are usually produced into short spines. Some specimens hear a terminal spiniform tubercle upon the margin between the last two annulations. The pleura) and articulating grooves are punctate. Doublure broad and flat. Dimensions. A thorax from the Hamilton shales measures 6 mm. in length and 10 mm. in width ; a pygidium from the same formation 6.5 mm. in length and 9 mm. in width; a small pygidium from the Upper Helderberg limestone 3 mm. in length and 5 mm. in width. Distribution. Upper Helderberg group. Corniferous limestone: In the de- composed chert boulders, Canandaigua. Ontario county. Hamilton group: In the lower shales at Canandaigua and Fall Brook, Hopewell, Ontario county : Eighteen-Mile creek, Erie county. Phaethonides oyceurus, n. sp. PLATE XXIV, FIG. 26-28; and PLATE XXV, FIG. 11. Cephalon. The intra-sutural portion, which is the only part known, indicates a semicircular outline for the head; frontal and lateral areas depressed and 138 PALjEONTOLOGY OF NEW YORK. concave ; frontal margin elevated, rising to the height of the glabella, broad, thickened and rounded. Palpebral lobes conspicuous. Glabella sub-pyriform, convex, slightly flattened above, bounded by a sul- cus which is strong at the sides and obsolete in front. Baso-lateral lobes strong; antero-lateral impressions well marked. Cheeks appressed and elevated along the lateral margins of the glabella. Thorax not observed. Pygidium semicircular ; length to width as 1 to 2. Axis prominent, elevated and longitudinally arched ; width less than one- third that of the shield, rapidly tapering to an apex just within the posterior border ; composed of nine annulations which are transverse, rounded and separated by moderately broad sulci. Pleural evenly rounding to the flattened border, and bearing seven annula- tions, which are strongly sulcate. Border broad, depressed or flat. All the pleural annulations pass over the border to its edge, where the anterior and posterior limbs are of equal strength. Doublure broad. Surface Ornamentation. The cephalon shows traces of low pustules over the glabella, and upon the depressed frontal area, where they become elongate or lachrymate, sometimes anastomosing, leaving elongate depressions between them; the frontal border also bears an irregular row of conspicuous tubercles. The pygidium is marked by regularly arranged pustules; a median row upon the axis, bifurcating at the fifth or sixth annulation, thence backward con- tinuing double until it becomes obsolete. Four rows of finer pustules are also visible on the axis, two on either side of the median row. The pleurae bear three or four rows of small pustules, and the interspaces of the crust are minutely granulose, and punctate. The lower surface of the doublure is marked by faint radiating or venate striations. Dimensions. The single fragment of the cephalon has a length of 7 mm. ; the pygidium measures 6 nun. in length and 9 mm. in width. CRUSTACEA. 139 Observations. This species does nol widely differ from the Proetus Macrobius, of Billings, from the Lower Helderberg of Square Lake, Maine. The latter species, however, is of considerably larger size, and also differs in the following particulars, viz. : the frontal area is not concave: the glabella is Longer; the axis of the pygidium bears fewer annulations, and the surface of both cephalon and pygidium is smooth or minutely punctate. This rare species is known in only a few specimens of the cephalon and pygidium. One example shows the two parts in juxtaposition, and from this fact, and from the analogy of other species of this genus, it is more than probable that they belong to the same species and the same individual. Distribution. Lower Helderberg group. In the shaly limestone: Near Clarks- ville, Albany county. PHAKTHONIUES (?) DENTICULATUS. PLATE XXV, FIGS. 14, 15. Proetus (Phatton) denticulatus, Meek. U. S. Geol. Expl. Fortieth Parallel, part 1, Palaeontology p. -Ill ; pi i, fiys. 10, 10 a, 10 b. 1877. Certain fragments, consisting of the pygidium, the glabella and detached thoracic segments, were described by Mr. Meek under the above name, and though the different parts may not have all belonged to the same species, the pygidium, which the author accepted as the type of his description, appears to represent a member of the genus Phai'thonides. The original specimens have not been accessible for examination and comparison, and we therefore repro- duce the original description of the pygidium, accompanying it with figures copied from the work cited : "Pygidium transversely sub-elliptic, and nearly twice as wide as long, with a moderate convexity. Its mesial lobe is about as wide anteriorly as each lateral lobe (exclusive of their lateral spine-like projections), and more prominent than the latter, with three or four segments. The lateral lobes are rather depressed and show about four segments each ; these segments are not well defined, but have each a distinct mesial furrow, extending out to the margin, where each segment terminates in a short spine directed backward ; while there are two other smaller spine-like projections just behind the posterior end of the mesial 140 PALAEONTOLOGY OF NEW YORK. lobe; thus making ten of these projecting points to the whole of the free posterior and lateral margins. The surface shows a finely granular appear- ance under a magnifier." This pygidium is different in many respects from the others here referred to the genus Phaethonides, and is more nearly similar to the forms which it was the evidenl intention of M. Barrande to include under the term Phaeton. The glabella found in association with the pygidium, if correctly referred to the same species, is also different from those of the other American members of the genus, being distinctly proetoid and conforming with that of Phaeton plani- cauda and Ph. striatus, Barrande. This species, when better known, may serve to establish the group designated by M. Barrande with the preoccupied term Phaeton, as generically distinct from Pha ethonides. Distribution. From the west side of Steptoe Valley, Nevada : "Although not found associated with other fossils, they are believed to belong to the Devo- nian epoch." (Meek, he. cit.) CYPHASPIS, Burmeister, 1843. CyPHASPIS MINUSCULA. PLATE XX, FIG. 17; and PLATE XXIV, FIGS. 7-12. Phillipsia minuseula, Hall. Illustrations of Devonian Fossils, pi. xx, tiys. 17. 1876. General Form and Proportions. Outline ovate, posteriorly sub-attenuate. Surface depressed-convex, sub-equally trilobate. Axis evenly tapering. Length to width as 3 to 2; axial length of cephalon, thorax and pygidium as 3 to 6 to 1. Cephalon scnii-elliptical in outline, curvature slightly changing at the genal angles, which are produced into spines having an outward curve and reaching almost to the pygidium. The facial sutures take their origin on the posterior margin near the genal angles, pass obliquely forward over the palpebral lobe, thence outward and forward, approximating toward the margin and terminating on the frontal doublure. CRUSTACEA. 141 Glabella sub-pyriform, evenly convex, sometimes slightly elevated along the axial line; bounded by a strong sulcus, which is shallowest near the palpebral lobe. Basal lobes pyriform, conspicuous: baso-lateral furrows strong; antero-Iateral impressions faint. Frontal area scarcely appressed against the glabella, evenly convex and depressed near the margin which is thickened and slightly reflexed. Eyes elevated, conspicuous. Palpebral lobes relatively small. Cheeks sloping more or less abruptly from the orbital area to the thickened margin. Thorax elongate; axis and pleurte evenly tapering, the latter at about one- third their width from the axis abruptly deilected to the lateral margins. Segments fifteen, each one of which is sulcate upon the pleurae, the anterior limb being inconspicuous and becoming obsolete by the development of the beveled planes of articulation. Pygidium small; width greater than twice the length. Axis strongly arched and bearing three annulations with traces of a, fourth, beyond this point becoming obsolete just within the posterior margin. Pleura with abrupt lateral slopes and showing two faint duplicate annula- tions. Doublure narrow. Surface smooth, sometimes finely granulose or minutely papillose, and rarely tuberculate. The occipital ring of the cephalon occasionally bears a single short spine at its center. Hypostoma. A single imperfect example shows the hypostoma slightly dis- placed from its normal position. This organ is sub-quadrate, with the centrum evenly convex, and separated by a furrow from the flat marginal area. Anterior margin straight (?) ; lateral margins slightly incurved, wid- ening posteriorly, posterior margin emarginate. Dimensions. A representative individual affords the following measurement: B. uly. Cephalon. Thorax. Pygidiuin. Length 13 mm. 4.5 mm. 7 mm. 1.5 mm. Width 8 mm. 8 mm. 7 mm. 3.5 mm. 142 PALEONTOLOGY OF NEW YORK. Observations. Cyphaspis minuscula has usually been observed as casts of the lower surface. Fragments of the cephalon in this condition of preservation are far from uncommon in the decomposed chert of the Corniferous limestone. From Cyphaspis craspedota, of the Hamilton group, the species is distinguished by the more abrupt curvature of the frontal area of the cephalon, the longer genal spines, and the greater number of thoracic segments, . none of which appear to bear any spines. It may be compared with Cyphaspis Halli, Barrande, from the Bohemian etage E, which it closely approximates in the characters of the cephalon. In that species, however, the glabella is more elongate, the basal lobes less conspicuous, the pygidium relatively larger and with more annula- tions than in Cyphaspis minuscula. Distribution. Upper Helderberg group. Schoharie grit : Clarksville, Albany county. Corniferous limestone : Schoharie, Schoharie county ; Phelps, Ontario county; LeRoy, Genesee county ; Clarence, Erie county. In the decomposed chert boulders, Canandaigua and East Bloomfield, Ontario county ; North Cayuga, Province of Ontario. Cyphaspis stephanophora, n. sp. PLATE XXIV, FIGS. 2-6. Cephalon. Outline transversely semi-elliptical; length to width as 1 to 1.7. Genal angles produced into recurved spines which are longer than the axial length of the cephalon. Border spinose and thickened by doublure Frontal area narrow, convex and appressed about the glabella, anteriorly depressed by abrupt curvature to the thickened, slightly reflexed anterior margin. Facial Sutures, normal for the genus, originating on the occipital annula- tion just within the genal angles, passing obliquely forward and inward to i lie eye-lobe, thence forward and outward to the anterior margin. Glabella extending three-fourths the length of the cephalon, sub-pyriform, convex, bounded by a strong sulcus which becomes shallow over the ocular lobes. Basal lobes pyriform; baso-lateral furrows deep; antero-lateral im- pressions faintly discernible. CRUSTACEA. L43 Cheeks elevated about the orbital node and sloping abruptly to the thickened margin. Palpebral lobes elevated: visual surface not observed. The Surface of the cephalon is ornamented l>y strong, scattered pustules which become obsolete upon the border and the genal spines. Upon the occipital ring is a single, strong, spiniform tubercle, generally accompanied by a smaller one on either side. The anterior and lateral margins of the cephalon bear two rows of strong spines, one above the other: those of the upper row being the longer and having their bases upon the proximal surface of the marginal rim. The proximal surface of this rim lies vertically upon the margins of the cheeks, and hence the spines which stand perpendicular to its surface, lie in the horizontal plane ; as it approaches the frontal margin this rim becomes turned upward and slightly reflexed. so that towards the anterior extremity the spines of the upper row stand at an angle of nearly forty-five degrees to the horizontal. The spines of the lower row are shorter, lying in the horizontal plane on the frontal margin, and deflected below the horizontal plane on the genal margins. Of these spines there are about eighteen in the upper and sixteen in the lower row. A single fragment of a thorax associated with a cephalon of this species, shows a very wide and gently arched axis, six narrow and flattened segments each bearing a number of strong pustules, of which there are two longitudinal rows upon the pleurae, and for each segment of the axis five or six pustules which do not appear to be arranged in longitudinal rows. This appearance may, however, be due to the imperfection of the specimen. Dimensions. Length of cephalon 4 mm.; width at the posterior margin 7 mm. ; length to the extremity of the genal spines 8 mm. Observations. The striking ornamentation of the cephalon of this species finds its analogue in Cyphaspis Cerberus, and C. Davidsoni, Barrande, from the etage F, and in C. coronata, Barrande, from the etage G. In these species there is but a single row of spines, which in C. Cerberus are short and numerous, in C. Davidsoni broad and stout, and in C. coronata more like the upper row of C. stephanophora, but fewer in number. I I I PALEONTOLOGY OF NEW YORK. Distribution. Upper Helderberg group. From the decomposed chert boulders of the Corniferous limestone: Canandaigua and East Bloomfield, Ontario county. Cyphaspis diadema, n. sp. PLATE XXIV, FIG. 13. A single example of this species showing only the intra-sutural portion of the cephalon has been observed. Cephalon minute; length and width equal; curve of the anterior margin an arc with its center at the middle of the occipital annulation ; frontal area broad, gently convex and slightly appressed about the glabellar margins, depressed medially and reflexed upward to the marginal rim. Facial Sutures normal. Glabella one-half the length of the cephalon, elongate, sub-elliptical ; basal lobes obscure ; antero-lateral impressions discernible. Palpebral lobes prom- inent. Surface minutely pustulose upon the glabella, the palpebral lobes and on the frontal area close to the glabella. About half way from the anterior extremity of the glabella to the frontal margin is a single row of minute but isolated and distinct tubercles, parallel to the frontal margin. This feature is characteristic and will serve to distinguish the species. Dimensions. The single specimen has the following size : length 1.7 mm., width 2 mm. Distribution. Upper Helderberg group. Corniferous limestone : From the boulders of decomposed chert, Canandaigua, Ontario county. Cyphaspis hybrida, n. sp. PLATE XXIV, FIG. 14. Intra-sutural portion of the cephalon only observed. Outline regularly arcuate; length ;md width equal; frontal area concave, elevated at the margin to nearly the height of the glabella. Border broad, thickened. Facial Sutures normal. CRUSTACEA. 145 Glabella pyritbnn, convex ; basal lobes conspicuous, sub-triangular ; baso- lateral sutures strong; antero-lateral impressions inconspicuous. Surface ornamented by punctae, which are strongesl on the frontal area near the margin. They are also noticeable over the entire surface of the glabella, basal nodes, occipital ring and frontal margin; moderately strong, scattered tubercles are visible on the glabella and over the fixed cheeks. The frontal border also shows faint indications of a single row of low tubercles. The differences in this species and Cyphaspis ornata and Phaethonides varicella are enumerated under the description of C. ornata. Distribution. Upper Helderberg group. Corniferous limestone: In boulders of decomposed chert, Canandaigua, Ontario county. Cyphaspis ornata. PLATE XXI, FIG. 1 ; and PLATE XXIV, FIG. 21. Phillipsiaf (BracTtymetapi/s ?) ornata. Hall. Illustrations of Devonian Fossils, pi. xxi, fig. I. 1876. Phillipxia coronata, Hall. Miller's Cat. Am. Palseoz. Fossils, p. L'21. 1877. [?] PhilUpsia coronata ?. Walcott. Mod.. U. S. Gfeol. Surv., vol. viii ; Pal. Eureka Dist., p. 211. l--si The original of this species consists of a fragment of the intra-sutural portion of the cephalon, and though additional specimens have come under observa- tion the other parts of the animal are still unkown. This portion of the head-shield is small, greatest length and width equal. Anterior outline the arc of a circle, whose center is at the middle of the occipital ring. Frontal area broad, explanate, closely appressed and slightly elevated about the margins of the glabella, thence depressed for about one-half its width and rerlexed at the frontal margin. The facial sutures take their origin on the posterior margin near the genal angles, pass obliquely forward and inward over the ocular lobe, thence forward and outward to the anterior margin in the manner normal to the genus. Glabella about one-half the length of the cephalon, sub-ovoid, a little ele- vated along the axial line, separated from the frontal area and the ocular ] ir, PALJEONTOLOGY OF NEW YORK. lobes by a low, narrow furrow. The baso-lateral furrows cut off two pyriform lobes, isolated by deep sulci on all sides. In front of these lobes the margin of the glabella shows two faint lateral indentations which are more con- spicuous on the casts of the internal surface. The surface of the cephalon is ornamented by a few faint, sometimes fine and crowded pustules upon the glabella, a single strong tubercle on each of the basal lobes, numerous sharp tubercles on the frontal area, and close upon the frontal edge sixteen to eighteen head-like tubercles arranged in a single row about the border. A single example has the frontal area strongly pit- ted, a feature which gives it a similarity to Phai'-thonides varicella, of the Upper Helderberg group. Dimensions. Length 4 mm., width 4 mm. Observations. The specimen figured in the Illustrations of Devonian Fossils (lac. cit.) is a fragment from the crystalline layers of the Hamilton group, at Eighteen-mile Creek, Erie county. As the species was described in the ex- planatory text accompanying the plate upon which the figure is given, under the name Pkillipsia? ornata, and it being subsequently ascertained that this specific term was preoccupied by Portlock for a species of Phillipsia, Mr. S. A. Miller changed the specific name to coronata (Catalogue of American Palaeozoic Fossils, p. 221). Since, however, the fossil proves to be a Cyphaspis, its original specific designation may be restored, especially as Cyphaspis coronata is a name already used by M. Barrande. Examples of this species are not uncommon in the limestones at the base of the Hamilton shales, in Ontario county, and in association with them is a varietal form which may be designated : Cyphaspis ornata, var. baccata, n. var. PLATE XXIV. FIGS. 22,23. This form differs from the type of the species in the following particulars, viz.: greater size (average dimensions, length 6 mm., width 5 mm.); frontal area bearing a few pustules near the glabella, but thence forward smooth and sometimes minutely pitted; tubercles on the margin fewer and larger; the CRUSTACEA. 147 right free cheek shows the genal angle produced into a broad sub-acute spine; the lateral margin carries a row of tubercles which continue with diminishing size to the angle of the cheek; the lateral sub-orbital area bears a few strong tubercles, the interspaces of the surface being faintly pitted. The Pkillipsia coronata of Walcott (Inc. fit.) is a somewhat distorted fragment of a cephalon from Newark Mountain, Eureka District, Nevada. The original specimen differs from the type of Cyphaspis ornata in its convex frontal ana. and in this feature resembles C. craspedola, of the Hamilton group, but the ornamentation of the frontal and lateral areas and of the border is similar to that of the former species, and the specimen thus appears to represent a form intermediate between the twro. Distribution. Hamilton group. Cyphaspis ornata, and var. baccata occur asso- ciated with Cyphaspis craspedota, Proitus Rowi, Proitus macrocephalus, Phacops rana, and Dalmanites Boothi, var. Calliteles, in the limestones at the base of the Hamilton shales, near Centerfield, Ontario county. C. ornata is also known from the upper shales at Fall Brook, Hopewell, and Canandaigua Lake, Ontario county, and Eighteen-mile Creek, Erie county. Our knowledge of the species Cyphaspis ornata, Cyphaspis hybrida, and Pha'e- thonides varicella, is yet so imperfect that the details of structure here given may eventually prove only of varietal value. The points of difference upon which the species are now separated are as follows: C. ornata is usually very sharply pustulose and minutely punctate on the frontal area, a single example which retains the characteristic beaded border, being strongly pitted and affording -a transitional form to the species C. hybrida, which is strongly punctate upon its entire surface bearing an elevated border upon which the tubercles are obsolescent. In Ph. varicella the surface is both tubercled and punctate, but not so strongly tubercled as in C. ornata, nor so strongly punctate as in C. hybrida, while the margin is thin and without tuberculations. As it has been necessary to refer one of these species to the genus Pha, i thon- ides, on account of its characteristic pygidium, it may be probable that the other 1 18 PALEONTOLOGY OF NEW YORK. two species, of which only the cephala are known, may belong to the same nis. but in the absence of conclusive evidence they are allowed to remain under the genus Cyphaspis, with which they agree in the characters of the head-shield. Cyphaspis craspedota, n. sp. PLATE XXIV, FIGS. 15-20. pare PhUlipsia coronataf Walcott. Monogr. U. S. Geol. Surv., vol. viii; Pal. Eureka Dist., p. 211. 1SS4. General Form and Proportions. Outline regularly oval, interrupted only by the projection of the genal spines. Surface convex, conspicuously and sub-equally trilobate. Axis prominent, elevated; pleurae abruptly deflected on the lateral slopes. Length to width as 3 to 2. Cephalon. Outline nearly semicircular; length to width as 1 to 1.6. Border thickened, slightly reflexed, produced at the genal angles into spines which reach to the sixth thoracic segment. Doublure narrow, epistoma indistin- guishable. Marginal sulcus broad; frontal area convex near the glabella, lateral areas depressed-convex, and abruptly sloping. Occipital furrow and ring distinct, the latter thickened at the cenfer. Facial Sutures normal. Glabella ovate or sub-pyriform, evenly convex, slightly flattened above ; bounded on all sides by a strong sulcus, which is shallowest near the palpe- bral lobes. Basal nodes conspicuous, pyriform or sub-triangular. Baso- lateral furrows strong; anterolateral impressions faint, and discernible only in casts of the lower surface. Cheeks depressed and sloping abruptly from the eye-lobe to the thickened border. Eyes conspicuously elevated, attaining the height of the glabella; base sub-pedicellate, slightly constricted. Visual surface sub-lunate, smooth, when strongly magnified, showing numerous homo-corneal lenses. Palpebral lobe strong, not projecting, sloping abruptly to the palpebral sulcus. CRUSTACEA. 149 Thorax elongate, length to width as L.3 to 1. Margins tapering with a regular curvature. Composed of twelve segments of which the first, fourth and sixth are the stronger, the last two being spiniferous. Axis broad and arched; width equal to one-third that of the thorax; widest at the third or fourth segment and tapering rapidly to the pygidium. Pleura, flattened near the axis for about one-third their width, and sharply deflected at the fulcra. Pleural sulci strong; anterior pleural limbs angu- lated by the articulating planes, not becoming obsolete on the lateral slopes as in most species of this genus. Posterior limbs of the pleural segments very strong. Pygidium minute ; length to width as 1 to 2. Axis broad, tapering rapidly to an obtuse termination within the posterior margin; bearing two strong annulations, with indications of a third. Pleura deflected, each bearing three double annulations, which become obsolete within the slightly thickened margin. Surface Ornamentation. Cephalon usually pustulose, the pustules being strongest upon the glabella and frontal area. The ornamentation upon these parts is often nearly obsolete, and the frontal margin generally quite smooth. sometimes with scattered obsolete pustules. The occipital ring, and the fourth and sixth segments of the thorax each bear a single slightly recurved spine, that upon the sixth segment being much the strongest On the axis are four rows of minute granules, two on each side of the median line The fulcra of the pleurae each bear a single row of small bead-like pustules. These rows of pustules, upon the axis and pleurae of the pygidium, approx- imate, and the posterior area is covered with scattered granulations. Dimensions. An average entire individual measures: Body. Length 12 mm. Width 6.5 mm. Fragments occasionally indicate slightly larger dimensions than the above. ( lephalon. 1 rax. Pygidium. 3.5 mm. 7 mm. 1 .5 11)1)1. 6.5 mm. 5.5 mm. 3 mm. 150 PALAEONTOLOGY OF NEW YORK. Observations. Cyphaspis craspedota is not an uncommon species in the basal limestones of the Hamilton group in the township of Canandaigua, where a few entire individuals and parts of several hundred others have been found. Its occurrence in other localities of this formation has not been noticed. The species is closely allied to Cyphaspis Burmeisteri, Barrande (Sys. Sil., vol. i, ]>. 484, pi. xviii, figs. 61-71), from the etages D and E. This similarity is apparent in the general form and proportions, the position of the eyes, length of the genal spines and character of the surface ornamentation. Moreover the sixth thoracic segment in C. Burmeisteri bears a strong spine, as in our species, but the occipital ring and fourth segment in the former species, are without spines. Barrande has also shown that the number of thoracic segments for mature individuals of his species is fourteen; in immature examples varying from seven to thirteen. All the entire individuals of C. craspedota show but twelve segments. The pygidium of the Bohemian species is also larger and more strongly segmented. C. craspedota probably finds a congener in the C. hydrocephala, Maurer, of the German middle Devonian (Fauna der Kalke von Waldgirmes bei Giessen, pi. xi, figs. 20-22, not C. hydrocephala, A. Roemer, L845; Barrande, 1852; Kay ser, 1878). Distribution. Hamilton group. In the shales and limestones directly over- lying the Marcellus shales: Near Centerfield, township of Canandaigua, Ontario county. Cyphaspis l^evis. PLATE XXI, FIG. 29. PhUUpsia Imoli, Hall. Illustrations of Devonian Fossils, pi. xxi, fig. 29. 1876. salon minute, outline semi-elliptical ; surface convex; border conspicuous, elevated and rounded, produced at the genal angles into moderately long, slightly incurving spines; marginal sulcus deep; frontal area evenly convex. Facial sutures normal, crossing the frontal area somewhat abruptly. Glabella sub-ovoid, convex ; basal lobes sub-pyriform, conspicuous; antero- lateral depression faint. Occipital ring not retained. CRUSTACEA. 151 Cheeks broad, depressed about the base of the eyes and sloping with slight concavity to the margins. Occipital furrow narrow and deep; occipital ring rounded. Eyes small, and elevated above any other portion of the head. Surface smooth or minutely punctate. The other parts of the animal have not been discovered. Dimensions of the cephalon. The single specimen which has been observed measures 2 mm. in length and 3.8 mm. in width. Observations. This species, in its general features, in the convexity of the fron- tal area and the smoothness of the test, appears to be closely similar to Cyphaspis minuscula. It differs from the latter in its more elevated and wider bonier and shorter cheek-spines, as well as in its smaller size, it being one of the most minute species of Cyphaspis yet observed in the Devonian rocks. Its occurrence in the beds of the Chemung group makes it the latest known representative of the genus, and with the exception of the somewhat doubtful species, Phacops nupera, is the only trilobite known from this formation. Distribution. Chemung group. Chemung county. Cyphaspis ccelebs, n. sp. PLATE XXIV, FIG. 1. General Form and Proportions. Outline elliptical, lateral margins rapidly curving to the pygidium. Surface depressed, distinctly trilobate. Axis broad, rapidly tapering posteriorly. Cephalon semi-elliptical in outline; marginal rim flattened, slightly reflexed; produced at the genal angles into spines, which extend to the pygidium. Frontal area convex, abruptly deflected from the glabella; lateral area depressed-convex. Glabella ovoid ; basal lobes distinct. Palpebral lobes high, distant; palpe- bral sulcus broad and deep. 152 PALAEONTOLOGY OF NEW YORK. Thorax elongate, rapidly narrowing. Composed of twelve segments. Axis broader than either lateral lobe, broadest at the fourth or fifth _inent and tapering rapidly to the pygidium. Pleura gently deflected at the fulcra, the segments being conspicuously sulcate. Ptgidium imperfectly known, probably very small. Surface smooth or minutely granulose. Dimensions : Body. Length 11mm. Width / mm. Cephalon. 3.5 mm. 7 mm. Thorax. 6.5 mm. 6 mm. Pygiilium. 1 mm. ? 2 mm. ? Observations. This species approaches Cyphaspis minuscula in the contour and outline of the cephalon, but the much greater width of the axis, more rapidly tapering margins and longer cheek-spines, will serve as distinguishing char act A -ingle imperfect individual retaining the parts in juxtaposition, and show- ing the lower surface of the test, and a fragment of the cephalon of another, are all the specimens known of this rare species, and constitute the only repre- sentative of the genus in this horizon. Distribution. Lower Helderberg group. Near Clarksville, Albany county ; Schoharie, Schoharie county. XIPHOSURA. LIMULID^E. PROTOLIMULUS, Packard. 1886. Protolimulus Eriensis. PLATE XXVI, FIGS. 1, 2. Prestwichia Eriensis, H. S. Williams. Amer. Jour. Science, vol. xxx, Third Series, p. J'!, figs. 1-3. 1885. Protolimulus Eriensis, Packard. Mem. Nat. Acail. Sciences, p. 150, figs. 11-13. 1886. The type specimen of this interesting species is an impression of the lower surface of the body, in very high relief, upon a block of fine-grained, compact, olive-gray sandstone. Its condition of preservation is such that the removal of the substance of the tenuous test, during the process of fossilization, and the infiltration of the sediments into the internal cavaties of the telson, genal and abdominal spines, has left these parts standing out conspicuously, while over the central portion of the fossil there are various impressions which appear to be those of the appendages, and indicate something of the structure of the ventral surface of the animal. In the original description of the species, these characters have been carefully studied, and have undoubtedly been given their full importance, for the medium in which the fossil is preserved is not of such a character as to retain, with perfection, such delicate impressions as the appendages of this animal would have made, and it is possible that the appear- ances described may to a certain degree be fortuitous or mechanical, and with- out structural relation to the fossil itself; there; is however a distinct symmetry in their arrangement, and it is important that the view of their mechanical origin be subordinated to that of their organic character. l-,l PALEONTOLOGY OF NEW YORK. The description of the fossil is as follows: ( (inline of the BODY (cephalothorax and abdomen) sub-circular or slightly ovate, the genal spines scarcely protruding to interrupt the regularity of the outline. Cephalothorax sub-semicircular in outline, genal spines produced as far as the tip of the first abdominal spines. The infolded frontal border is broad and convex anteriorly, narrowing to the base of the genal spines. In the axial line its edge, or a ridge upon its surface, appears to be connected with a bi- symmetrical, trifoliate plate, which lies in front of the probable position of the mouth and extends backward, its largest lobe lying in the axis. This has been regarded by Mr. Williams as possibly an hypostomal plate. It may be suggested, that if this body were continuous with the frontal border the apparent posterior margin of the doublure might be regarded as a sharp ridge upon the lower side, curved backward in the axial line, similar to that in Limulus and Prestwichia. Such an interpretation of this character is not unsupported by the appearance of the fossil and obviates the necessity of supposing the animal to have differed from the Limulida in the possession of an hypostomal plate, while agreeing in other respects. Behind the margin of the infolded test, lies a series of indistinct impressions of narrow append- ages, of which three and possibly four pairs are discernible. They appear to be centered about a cavity close behind the apex of the doublure and to bend outward and upward in a broad curve. Near the genal spines on either side is a conspicuous, irregularly striated area, which Mr. Williams has suggested may be the impressions made by the foliaceous terminations of the last pair nl limbs; they are certainly very suggestive of such an origin. Behind these appendages and situated at about the center of the surface of the fossil is a transversely-elongate, triangular impression having the position of the thoracic or opercular plate in Limulus 'Ami the Eurypterida. The apex of this impression lies in the axial line, its lateral slopes are long and its Length is less than one-half its width along the posterior margin. Two parallel longitudinal furrows divide it into median and lateral areas, and these CRUSTACEA. 155 furrows appear to be "carried for a considerable distance posteriorly over an area that may have been the continuation of this plate. Admitting that it was thus produced, there is evidence that it was divided by a transv< furrow or suture, making the analogy of its structure with that of the thoracic plate in Limulus very striking. Abdombn. The posterior surface of the body hears a transverse row of eight, possibly ten longitudinal ridges, which may he the impressions of elevations on the surface of the abdominal area. These correspond in number with, and lie immediately in front of the stout spines fringing the postero-lateral margins, although the inner pair of spines lies so close against the base of the telson as to have left only very faint impressions. Telsox very stout at its base, tapering to a blunt extremity, and having a length equal to nearly two-thirds that of the cephalothorax. Dimensions. Axial length 100 mm.; width 58 mm. Length of telson 32 mm. Observations. The affinities of this fossil, as far as it is possible to judge, are distinctly limuloid, as pointed out by Professor Packard (he cit.), who has proposed the generic term Protolimulus to include this form. Both Williams and Packard ascribe to the fossil seven abdominal segments, including the telson; we have, however, been able to find evidence of but six, though it may he reasonable to assume that the first or first two of these segments were concealed by the appendages of the animal. The character of the dorsal surface is a matter of conjecture, but as far as the specimen enables us to form a conception of it, it seems to be closely similar to that in the genus Neolitnulus, of Woodward (N. falcatus, from the Lesmahagow deposits of Lanarkshire), in which the abdomen is composed of nine segments besides the telson, which are regarded by Woodward as unanchylosed ; it is probable that this is likewise their condition in Protolimulus. Distribution. Chemung group, LeBoeuf, Erie county, Pennsylvania. EURYPTEH/IDA EURYPTERID.E. EURYPTERUS, Dekay. 1825. EURYPTERUS BEECHERI. PLATE XXVII, FIG. 5. Elirypterus Beecheri, Hall. Second Geol. Surv. Pennsylvania, PPP, p. 30, pi. iii, fig. 1. 1S84. Cephalon unknown. Body elongate, broadly convex along the dorsum, becoming more elevated pos- teriori v ; composed of twelve somites, which gradually increase in breadth from the first to the fifth; thence backward rapidly decreasing in width and increasing in length, the eleventh having a length equal to one-half its width, while the fifth is nearly five times its length. The surface of the somites toward the lateral margins is depressed, the margins themselves being slightly produced at the postero-lateral angles into mucronate exten- sions. The posterior dorsal margin of each somite bears a single row of triangular scales or tubercles. The number of these scales varies with the width of the somite, there being six on the narrower and eight or more on the broader somites. At the anterior portion of the specimen are preserved two joints of one of the great swimming feet, which are remarkable for their length and the three or more strong longitudinal ridges upon their surface. The distal joint has a length of more than three times its width, and the proximal joint a length of nearly live times its width. These joints are probably the fourth and filth, thi' smaller joints near the base of attachment having disappeared. CRUSTACEA. 157 Telson and appendages unknown. Dimensions. The single specimen from which this description is drawn is somewhat curved to the left toward the posterior extremity, and has a length along the axis of 97 mm. The body measures 39 mm. in width at the first somite, 41 mm. at the fifth, and 20 mm. at the eleventh. The fragment of the natatory appendage measures 50 mm. in length, of which the proximal joint measures 30 mm. Observations. This specimen, although in an imperfect condition, is suffi- ciently well-preserved to allow of description and identification, and is of especial interest as the only representative of the genus known to occur in this geological formation. Distribution. Chemung group. In the sandstones at Warren, Warren county, Pennsylvania. EURYPTERUS PROMINENS. PLATE XXVII, FIGS. 3, 4. Euriipterii.i promineiis. Hall. Proc. Amer. Assoc. Adv. Science, vol. xxxiii, \>. -120. 1884. Cephalon sub-quadrate in general outline ; anterior margin broadly circular, curving regularly to the lateral margins, which are parallel ; posterior mar- gin transverse, bending slightly forward. Surface convex, sloping more abruptly in front than laterally ; flattened above over a triangular area, bounded by a faint transverse ridge joining the centers of the eyes and two oblique ridges passing from the posterior angles of the eyes to near the posterior margin, meeting in the axial line. The eyes are large, lunate or obliquely ficulate, distant, situated near the antero-lateral margins. The surface of the cephalon beneath their outer edges is depressed. The ocelli are represented by two minute pits lying near the axial line and in a transverse line joining the posterior extremities of the eyes. These are separated from each other by a distance of 2 mm. On the postero-lateral slopes are two oblique linear depressions having the lower extremities directed inward. These are each situated about half way PALEONTOLOGY OF NEW YORK. from the axial line to the margin, and may represent processes on the lower surface of the test designed for the attachment of the basal joints of the swimming feet or of the muscles moving those joints. Dimensions. The specimen here described has a length of 28 mm., a width of 30 mm., and a height of 5 mm. The distance between the posterior extremities of the eyes is 16 mm. ''inns. This species is described from a specimen of the cephalon preserved in a block of sandstone and retaining the normal convexity of this part. Although only this fragment of the animal is known, it appears to be distinctly different from any species of Eurypterus heretofore described, and its specific validity rests upon the following features: (a) the convexity of the head-shield; (b) the anterior position of the eyes; (c) the ocelli, situated further back than is usual ; (d) the flattened summit of the cephalon ; (e) the oblique linear depressions on the postero-lateral area. Distribution. Clinton group. In the greenish sandstones from the northern part of Cayuga county. STYLONURUS, Page. 1856. Stylonurus excelsior. PLATE XXVI. Stylonurus excelsior (Stylomurus in error), Hall (Martin). Trans. N. Y. Acad. Sciences, vol. ii, p. 8. 1882. !ts excelsior, Hall. Thirty-sixth Ann. Kept. N. Y. State Mus. Nat. Hist., p. 77, pi. v, fig-. 1. 1883. Stylonurus excelsior, Hall. Proc. Amer. Assoc. Adv. Sciences, vol. xxxiii, p. 421. 18S4. ire Dolichocephala Lacoana, Claypoi.l. Proc. Amer. Phil. Soc, vol. xxi, p. 236, plate. 1883. Cephalon elongate, semi-ovate ; length to greatest width as 6 to 5. Basal margin transverse; baso-lateral angles truncate; lateral margins curving gently outward from the base, thence sloping more rapidly forward to the narrow' anterior extremity. Surface depressed-convex. Eyes large, circular, closely appressed, situated just in front of the greatest transverse diameter of the plate and separated by a prominent median ridge. Each eye is encircled on its outer edge by a conspicuous, sub-semicircular CRUSTACEA. L59 orbital ridge. These ridges slope gradually outward, bul more abruptly on their inner faces, their anterior extremities approximating tbe median ridge at its widest and most elevated portion. This median ridge is rounded and comparatively smooth as far backward as the posterior margin of the eyes, at which point it is interrupted, thence widening posteriorly into a broad, blunt, eoarselv tuhercled termination ; toward the anterior extremity it becomes merged in the general convexity of the shield The Surface of the cephalon over the anterior region has a general and regular convexity toward the frontal margin, becoming a little more convex about the anterior extension of the orbital ridges. From near the posterior extremities of these orbital ridges runs an irregularly sigmoid depression, which widens and becomes obsolete just within the baso-lateral margins. The median area behind the eyes is depressed-convex or flattened, and is divided into three parts, a narrow central area, apparently a continuation of the longitudinal ridge passing between the eyes, and a broad, sub-semicir- cular area on either side. Behind this gently elevated region lies a broad, nearly smooth depression, followed by the elevated posterior border. The ornamentation of the surface consists of conspicuous, squamiform tubercles, which are elongate and most elevated over the anterior portion of the shield, but become broader and more triangular posteriorly. They are arranged in lines concentric with the margin of the shield or with the most prominent features of its contour. Within the orbital ridges these scaly markings are comparatively fine, and over the depressed posterior area are quite obsolete. Other parts of the animal are unknown. Observations. The specimen from which the above description is drawn, con- sists of the intaglio and relievo impressions of a single cephalon. These were found in a loose block of fine-grained, olive-gray sandstone, in the town of Andes, Delaware county, and are now in the possession of Rutgers College, New Brunswick, N. J. The mould of the dorsal surface retains all the details of structure and ornamentation in great distinctness and perfection, and the Kin PALEONTOLOGY OF NEW YORK. drawing which accompanies this description has been made from a plaster im- pression of this natural mould. The cephalon in S. excelsior is more elongate, the anterior extremity narrower and the orbital ridges very much more prominent than in any other known species. It has an axial length of 252 mm., and a width of 223 mm., or a length of about ten and a width of about nine inches. It undoubtedly repre- sents one of the largest of palasozoic Crustacea, probably the largest known with the exception of Pterygotus anglicus. By comparison with the other species of Sti/lonurus, S. Logani, and S. Powriei, Woodward, of which the length is known either from entire specimens or approximate restoration, it appears that & ex- celsior would have measured, when entire, upward of fifty inches in length. Distribution. Catskill group. Andes, Delaware county. Stylon0rus(?) (Echinocaris?) Wrightianus. PLATE XXVII, FIGS. 7-9. Equisetides Wrightiana, Dawson. Quart. Jour. Geol. Soc, vol. xxxvii, p. 301, pi. xii, fig. 10; and pi. xiii, fig-. 20. 1881. Equisetides Wrightiana (Dawson), Hall. Thirty-fifth Rept. N. Y. State Mus. Nat. Hist.: Expl. pi. xv. Note, and figs. 1 and 2, (Transmitted, 1882). 1884. Echinocaris Wrightiana, Jones and Woodward. Geological Magazine, Dec. iii, vol. i, No. 9, p. 3, pi. xiii, figs. 1, a and b. 1884. K mm. in length and 4.5 mm. in width; the second 7.5 mm. in length and 3.7 mm. in width, and the longer of the caudal spines has a length of 12.5 mm. The specimen has been so flat- tened in the shale that superficial markings are not discernible. But a single example of this species has been observed, and this is from the black slaty shale I hi PALAEONTOLOGY OF NEW YORK. och. The fossils originally illustrated in association with this S teentl, Kept N. Y. State < lab. Nat. Hist., figs. 4, 5 and 6, lac. cit.), and . the publication of the description, regarded as detached caudal individuals of the same species, prove to be specimens of the /. . Hall. An undescribed species bearing very long and ,,,/,:;! spines is, however, known to occur in this formation, and it is distinct from Ceratiocaris longicavda. This undetermined species is the one referred by Clarke {he. cit.) to Ceratiocaris longicaudus. . Hamilton group. Genesee shales: Bristol, Ontario county. I I IB mocAius Beecheri. PLATE XXXI, FIG 3. I , lKKB. Bull. U. 8. Geol. Surv., No. 16, Higher Devonian Faunas of Ontario county, N. Y.. p. 44, pi. ii. fig. 1. lsv-">- The original of this species consists of the two posterior abdominal somites and the lomen, no additional examples having been observed. The specimen has been Battened in a soft shale, and its surface ornamentation not. distinctly preserved. There appear to he no lateral or marginal spines upon the somites and the species is therefore referred to the genus Ceratiocaris. ' ' the two abdominal somites the anterior is relatively short, with anterior and posterior margins slightly incurved. Its length is 3 mm., and its width mm. The posterior somite is longer, measuring 8 mm. in length and 5 mm. in width. The caudal plate is sub-triangular on the dorsal surface; the telson rather stout. Id mm. in length; the cercopods, of which a portion wanting, a little longer. All these spines are carinate, the telson along the middle and the cercopods on their lateral margins. In the Cashaqua shales of the Portage group as originally ■ Naples beds," of Clarke). Son Yea, Livingston county. CRUSTACEA. 165 CERATIOCARIS (?) SIMPLEX. PLATE XXXI, FIG. 2. Ceratiocaris simplex, Clarke. Bull. U. S. Geol. Surv., No. l(i, Higher Devonian Faunas of Ontario county, N. Y., p. 43, pi. ii, fig. 2. 1885. The characters of this species are quite obscure, the type specimen being a cast of the internal surface of the cephalothorax. This appears to be bivalvular, oval in outline, the hinge-line gently curved. The anterior extremity is some- what broken, but appears to have been obliquely truncate or slightly notched ; the ventral margin has about the same degree of curvature as the dorsal line, and the posterior extremity is sub-acute. Surface convex, sloping gently to the ventral margin, but much more abruptly to the dorsal line. The margin is distinctly thickened on all sides and was probably somewhat elevated. No evidence of ornamentation is visible. The single valve measures 29 mm. in length by 12 mm. in width. Distribution. In the lower shales of the Portage group as originally defined (" Naples beds," of Clarke). Parrish gully, Naples, Ontario county. l66 PALEONTOLOGY OF NEW YORK. ECHINOCARIS, Whitfield. 1880. ECHINOCARIS PUNCTATA. PLATE XXVII, FIG. 10; PLATE XXVIII, FIGS. 1-7; and PLATE XXIX, KIGS. 1-8. s, Hall. Sixteenth Rept. N. Y. State Cab. Nat. Hist., p. 74, pi. i, fig. 8. 1863 tatus, Hall. Si Rept. N. V. State Cab. Nat. Hist., p. 72, pi. i, figs. 1-3. 1863. . II mi,. Illustrations (if Devonian Fossils, pi. xxiii, figs. 4, 5. 1876. tis, Hall. Illustrations of Devonian Fossils, pi. xxiii, fig. 7. 1S76. iitfield. Journal of Science, Third Series, vol. xix, p. 37. 18S0. . Mti). Palaeozoic Allies of Nebalia. Amer. Naturalist, p. 952, fig. 12. 1882. . Packard. Monog. North Amer. Phyllopod Crust. Twelfth Ann. Rept. U. S. Geol. Survey, p. 451), fig. 70. 1S83. M og. North Amer. Phyllopod Crust. Twelfth Ann. Rept. U. S. Geol. Survey, p. 451. L883. [BR. Ceratiocaridse from the Chemung and Waverly groups. Second Geol. - u-v. P a . vol PPP, p. 6, pi i, figs. 13-16. 1884. ! - Ji ill Woodwakh Notes on Phyllopodiform Crustacea, referable to the genus Magazine, l»ec. iii, vol. i, No. fl, p. 2, pi. xiii, fig. 2. 1884. Woodwabd and Jones. Third Rept. Committee on Fossil Phyllopoda of i he Palaeozoic Rocks, p. 35. 1885. Cephalothorax Each valve obliquely sub-ovate, widest posteriorly. Surface gently and irregularly convex, most elevated in the postero-lateral region. Length to greatesl width as 1.5 to 1. Hinge-line short, somewhat longer than one-half the length of the carapace, slightly thickened and elevated, nHBN long, slowly tapering to the caudal plate, and composed of six somites, which increase in length posteriorly, the ultimate joint being as long as the lirst two, and one-half longer than the penultimate. The anterior and pos- targins of each somite are slightly elevated and incurved on both dorsal and ventral sides; the dorsal surface is rounded and gently concave . excepl upon the last somite. The posterior margin of each somite short incurved spines, in three pairs. The strongest pair of these ll"' dorsa] surfaci cond and somewhat shorter pair upon the surface, and a third [.air (in young individuals often very upon th- lateral margins. Upon the anterior somites these spines are quite Bmall or visible only as nodes. The ventral surface bears 'ticulating surfaces of the somites are broad, and when men is normally extended they come into actual contact only at both the dorsal and ventral margins distant, a fact which " I >>. Beecher) greal freedom of motion in these parts. CRUSTACEA. 1G9 Post-abdomun. Caudal plate short, sub-quadrangular upon the ventral side, and sharply elevated on the anterior edge; sub-pentagonal on the dorsal side, elevated in the middle on the posterior half, and produced into a telson which is usually about twice as long as the last somite. Articulated to the caudal plate are two lateral spines or cercopods, each longer than the telson. Each of the three spines is elevated or carinated upon the dorsal surface, the telson grooved along the sides, and the cercopods grooved upon the ventral surface. Surface of the abdomen and caudal spines smooth or finely granulose. Dimensions. Although specimens of Echinocaris punctata are not uncommon at certain localities, the parts are usually disjointed and entire individuals are extremely rare. The most complete specimen observed (pi. xxviii, fig. 3), is of average dimensions and measures as follows : Length Body. Cephalo thorax, Abdomen. Post-abdomen 77 mm. 28 mm. 35 mm. 23 mm. 40 mm. 20 mm. 6 mm. Width The somites of the abdomen in this specimen have the following lengths : First, 4 mm.; second, 4.5 mm.; third, 5 mm. ; fourth, 6 mm. ; fifth, 6.5 mm. ; sixth, 9 mm. The largest individual observed in which the parts are in conjunction affords the following measurement : Body. Cephalothorax. Abdomen. Post-abdomen. Length 195 mm. 68 mm. 96 mm. 39 mm. Width 88 mm. 44 mm. A single very large carapace has a length of 90 mm., and the individual to which it belonged must have been about 244 mm. or nearly 10 inches in length when entire. Observations. Specific Diagnosis. The specimen from which the original description of Ceratiocaris ? punctatus, Hall (loc. cit.), was drawn, is a large carapace, represented both in the figure given in the Sixteenth Report of the State Museum, and also in the Illustrations of the Devonian Fossils, with a strong node at the posterior extremity of the dorsal line. This node proves lT.i PALEONTOLOGY OF NEW YORK. of the matrix of the specimen, but otherwise it i.s a well 1 representative of the species. At the time of the preparation ption the parts of the animal had nol been found together, and domen and post-abdomen of another individual were taken as the species Ceratiocaris armatus. Material which has come into the ion of the State Museum since that date, establishes beyond a doubt the the two species. Both descriptions were published at the same nd although that of tlie latter species precedes that of the former by two pages in the letterpress of the report referred to, it appears wiser to cognition to the specific name pundatus, a- C. pundatus was founded upon the portion of the animal most characteristic and important for specific inination. Echinocaris pundata shows some points of general similarity the species E. sublavis, /.'. multinodosa, Whitfield, and /<]. socialis, Beecher, iilv distinguished from them by the size and disposition of the nodes, irve of the lateral carinas on the carapace, the length of the abdominal somites and the character of their spinous processes. ibufion. Hamilton group. In the black shales at Pratt's Falls, near Pomp I iter and at Delphi, and in the sandy shales, near Fabius, Onondaea county ; in the higher shales at Menteth's Point and Tichenor's Glen, Canan- j and near Norton's Landing, Cayuga hake. ; 0F Puvllocaiuda dissociated with Echinocaris punctata, in the finch has produced the greatest number of specimens, viz., Pratt's Pompe^ Center, Onondaga county, large masticatory organs ' 'I'"1" abundantly, which, judging from a general similarity found in situ in this species, may be regarded as undoubtedly I iesof the Phyllocarida. Beecher has described and these bodies (ft*, eft), and has indicated the fact that if bearing l"',""M ,'" *»I»ce as do the mandibles in E. pundata, they longed either to large individuals of this species or to some unknown to us. CRUSTACEA. 171 Barrande had earlier described and figured similar bodies (Syst. Silur. Boheme, vol. i, Suppl. p. 443, pi. xxi. figs. 41-44. 1872), from the I'lage E., associated with Ceratiocaris, and regarded them as the masticatory organs of individuals of that genus. These mandibles are generally somewhat trian- gular in outline, with sometimes a straight but usually curved or lunate crown. This crown or masticating surface is broad, and bears five, six or seven cuspid denticles, of which those at the extremities are more pointed, simple and canine-like; those between having a surface strikingly similar to that of the human molar. The lower or basal portion of the mandible is broad and in many instances the surface of attachment is somewhat pro- duced behind into the manubrium. The substance of this portion of the mandible is much thinner than that of the grinding surface, and on account of its being often crushed, the manubrium is frequently not apparent, and in young individuals it seems not to be developed. Judging from the relative proportions exhibited in the length of the mandibles, and of the entire animal in E. punctata, the largest of these bodies observed, which has a length of 38 mm., may have belonged to an animal 390 mm., or upwards of fifteen inches in length. An individual of 'Ceratiocaris papilio, Salter, has been figured by Woodward (Geol. Mag., vol. ii, p. 501, pi xi, figs. 1. 2), in which the mandibles are visible through the substance of the carapace. They appear to be of the same general character as those here described, but much smaller in proportion to the size of the carapace, and if represented in their normal position, situated much more anteriorly. Woodward's figure indicates that these bodies have under- gone a vertical displacement, as both mandibles are equally distinct in a profile view of the specimen, and it is possible that a horizontal displacement has pushed them forward beyond their normal position. The figures of the mandibles of Dithyrocaris, upon the same plate, taken from a specimen de- scribed by Portlock (Geol. Kept. Londonderry, p. 315, pi. xii, fig. 6. 1843), show some minor differences in form and outline but apparently insufficient to be of value as generic features. l72 PALEONTOLOGY OF NEW YORK. ECHINOCARIS WHITPIELDI. PLATE XXIX, FIGS. 20, 21. ike. Bull. U. S. Geol. Sum , No. L6, Higher Devonian Faunas of Ontario inty, N. Y-, p. ••''■ pi- >'. fi£S- 3> 4- 1SS5 w elongate, irregularly hemicordate ; length of each valve some- what less than twice the width, greatest width through the center; margin distinctly elevated. Hinge-line long, straight, scarcely equal to the greatest length of the carapace; curving gently outward toward the anterior extrem- ity, whence the margin is abruptly deflected in a straight line for a short dis- tance, and then sharply curved to the anterolateral edge, which is also nearly straight, rounding to the ventral margin which is sub-parallel with the hinge, the posterior margin being truncate and slightly incurved. 'ml furrow indistinct on account of the flattening of the specimen. I halic region relatively small, having less than one-third the width of the carapace; its surface is almost wholly occupied by a low node, well defined on it< posterior margin, but becoming obsolete toward the hinge. The surface of this node bears a number of elongate pustules. Close upon the hinge are two small tubercles, tic posterior of which probably represents the eye- node Tie Thoracic region, near the hinge-line and just behind the nuchal furrow, hears three parallel, elongate tubercles, one above the other; and behind them, ituated more ventrally, an indistinct transversely elongate node. A short ridge or carina takes its origin at the base of the cephalic node, near the ero-lateral margin, and passes obliquely backward nearly parallel to this mai oming i apidly obsolete. 'lie is marked by numerous low, scattered tubercles on the ventral postero-dorsal areas. On the cephalic region the finer sculpture is tely squamose, a feature not exhibited in other species of this genus. ■ unknown. tie fragmenl of shale which contains the carapace also CRUSTACEA. 173 bears a caudal plate, telson and one of the eercopods. The plate is sub- triangular, the telson moderately long but shorter than the cercopod ; all are strongly carinate, and the surface covered with indications of strong tubercles. Dimensions. The carapace of this species measures 28 mm. in length and 16 mm. in width across one valve. The telson is 28 mm. in length to the extremity of the spine, and the cercopod has about the same length. Distribution. But a single individual of this species has been observed, and this has been so flattened that some of its surface-features may be obscured. The original is from the lower beds of the Portage group as originally defined (the " Naples beds " of Clarke). Hatch Hill, Naples, Ontario county. EcHIXOCARIS CO.XDYLEPIS, 11. sp. PI. ATK XXIX, FIGS 11-17. Cephalothorax small, sub-ovate in outline; length to width upon each valve as 3 to 2 ; greatest width centrally. Surface depressed. Hinge-line straight, two-thirds as long as the carapace. Anterior margin gaping for a short dis- tance on the dorsal line, abruptly angled at the anterior extremity and rounding in a regular curve to the ventral margin and posterior extremity; at the latter point the margin is broadly angulated and passes thence ob- liquely forward in a nearly straight line to the hinge. The entire margin is moderately broad and thick and strongly elevated, especially upon the postero-dorsal edge. Nuchal furrow obscure. Cephalic region sub-triangular on each valve ; occupied by an irregular node, which is distinctly limited on its anterior margin by a sulcus strongly impressed near the hinge-line. This node bears four tubercles, which are placed at the angles of a square, two close upon the hinge-line and two situated ventrally. Of these the posterior ventral tubercle holds the posi- tion of the optic node in Echinocaris punctata. I7, PALEONTOLOGY OF NEW YORK. :haracterized by a strong transverse node just behind the nucha! furrow, acutely tubercled near the hinge-line, and beneath this an node extending from this furrow obliquely backward. A lateral ride ■ carina takes its origin near the anterior portion of the carapace and ickward in a broad sigmoid curve, becoming obsolete near the posterior region. A.bove this carina the postero-dorsal area is gently rounded and smooth. S smooth or minutely punctate. A OMEN ami iF.i.so.N unknown. Dim Three specimens of this species have been observed, and all ipproximately of the same size, viz.: length 9 mm., width 5 mm. \tions. Eckinocaris crmdylepis appears in many respects almost a minia- ure of Echinocaris punctata of the Hamilton shales. The nodes are essentially me in number ami disposition, though less conspicuous; the lateral carina s much shorter, hut has the same sigmoid curve; the ridge upon the postero- dorsal margin is. however, much more strongly elevated than in the latter 9 not tubercled or spinose. The general abbreviation of all the in which it resembles E. punctata is a persistent character, and it will iish the two species, while it may indicate their common origin. Chemung group, in the soft greenish shales at Philipsburgh (now Belmont), Mleghany county. Echinocaris sociaus. PLATE XXX, PIGS. 1 12 1= from the Chemung ana Waverly groups. Second Geol. Surv. 1 1'IT. y. 10, pi. i.figs. I 12. 1884. • w ward and Jokes. Third Rept. Committee on Fossil Phyllopoda of ' c Roi i . p. 35 1885. ■ obliquely sub-ovate in outline, widest posteriorly. Length along •■ to greatest width as I to L.5; to greatest length as 1 to 1.8. CRUSTACEA. 175 Hinge-line short, straight; anterior margin curving somewhat abruptly for a short distance, thence broadly rounding to the postero-ventral edge, there curving abruptly forward and passing in a nearly straight line to the poste- rior extremity of the hinge. Margins distinctly and sharply elevated on all except the dorsal side. Nuchal furrow scarcely distinct, cutting oil* a sub-triangular area on each valve, similar in relative proportions to that in E. punctata. The Cephalic region occupies about one-fourth the area of each valve, and its surface is mostly covered by a single large, elevated node, irregular in outline and when uncompressed, merging into one inconspicuous node lying near the dorso-lateral angle, another on the hinge-line at the nuchal furrow, and a third just opposite the nodiform termination of the lower thoracic carina. The Thoracic region bears two conspicuous nodes, one near the hinge-line, apparently continuous with the sharply elevated dorso-lateral margin, the other situated medially, abutting closely upon and often apparently con- tinuous with the lower carina. This carina lies at a little more than one- third the width of the valve from the ventral margin, takes its origin at or upon the median thoracic node and passes backward in a broad curve, be- coming extinct considerably within the postero-lateral margin. At a little more than one-half the distance between this carina and the hinge-line, there is a short, straight, or dorsally curved carinate row of sharp pustules. The postero-dorsal margin is also sharply elevated and sub-carinate near the hinge. The Surface of the carapace is covered with sharp, sub-spiniform pustules on its elevated portions, the depressed areas being smooth or minutely punctate. Abdomen composed of six somites, which become more elongate in outline toward the caudal-plate. Somites sub-cylindrical, bearing three transverse rows of posteriorly directed spinules. The first row of these lies just within the anterior margin ; the second about midway across the segment, and the third at the posterior margin. The spinules of the first row are often inconspicuous. PALEONTOLOGY OF NEW YORK. r.A„DOME« consisting of a short, triangular caudal plate, which is produced : . telson, having a length somewhat greater than that ,„,.,,. The cercopods have about the same length. A single specimen of average size retaining the parts in con- junction affords the following measurements: Body. Cephalothorax. Abdomen. Post-abdomen. Length 29 mm. 9 mm. 9 mm. 11mm. Width .-- 6mm- 2mm- This very distinctly defim d Echinocarid finds no close ally among the known Some points of similarity in general form and outline are suggested y the species /.'. ptistulosa and E. sublavis, Whitfield, but specific differences in the number and disposition of the carinas and the shape of the nodes are lily apparent. Its comparative abundance, at the single locality where it is known to occur, is interesting and in consonance with the known gregarious habits of both fossil and recenl forms of such crustaceans. D Iribution. Chemung group. " In the shales at the base of this group as exposed at Warren, Pa.; belonging to the upper strata of the series when jidered in illation to the entire thickness of the group in New York and nsylvania." (Beecher, he. tit.) ECHINOCARIS SUBLJEV1S. PLATE XXIX, KIGS 11-13. Forms of Fossil Crustacea, etc. Am. Jour. Science, 3d ser.,vol'. xix, pi. (unpublished), figs. 4, 5 and 6. 1880. Allies of Nebalia. Am. Naturalist, p. 952, fig. 11. Dec. 1882. M N. Amer. Phyllopod Crustacea. Twelfth Rept. U. S. Geol. Surv., !50, 151, fig. Tlli L883. br. Cei ii from the Chemung and Waverly groups, etc. Second Geol. Surv. Penna., vol. PPP, p. 5. 1884. and Woodward. Notes on Phyllopodiform Crustaceans referable to the genus 1 Dec. iii, vol. i. No. 9, p. 2. pi. xiii, figs. 3, 4 and 5. 1884. IB, W ward and Jones. Third Rept. Com. on Fossil Phyllopoda of the Palseozoic Rocks, p. 35. 1885. Outline obliquely sub-ovate, length to width as 3 to 2. ilarlv convex in front, evenly convex behind. Hinge-line CRUSTACEA. Ill short, straight, extending from the anterior margin two-thirds the length of the carapace. Anterior extremities very slightly gaping, the margin sharply rounding in front, passing in a broad curve obliquely to the postero- lateral region, whence it passes in a gentle curve or a direct line to the hinge. The type specimen is so incomplete that the posterior outline can not be accurately determined. The entire margin is elevate and carinate. Nuchal furrow distinct, taking its origin on the hinge at about one-third its length from the anterior extremity and passing obliquely forward. Cephalic region small, sub-triangular on each valve and entirely occupied by a strong elevated node, the surface of which is covered with scattered tubercles, but it is impossible to determine which of them has served as the optic node. Thoracic region just behind the nuchal furrow marked by a single, strong, obliquely elongate dorsal node, bearing a tubercle near the hinge-line. This node, at its inferior extremity, comes almost into contact with a nodiform ridge, directed obliquely backward and produced into a lateral carina, which is parallel to the ventral margin of the carapace. Postero-dorsal area smooth, broadly and evenly convex. Surface obscurely punctate. Abdomen. Portions of the last three somites are to be seen in one of the type specimens. Each of these is short, sub-cylindrical, the posterior segment being a little the longest. The anterior margin of each is elevated into an articulating ridge, and the posterior margin into a spiniferous ridge. Upon the dorsal surface the spines on each somite appear to have been very short and scarcely more than elevated tubercles, but on the lateral surface were quite strong. There appears also to have been a spine on the lateral surface of each somite between the anterior and posterior margins. Post-abdomen. The caudal plate on the dorsal side is sub-pentagonal, depressed on the postero-lateral areas. The telson begins as an elevated ridge near the anterior portion of the plate and is produced to a length probably equal- l7g PALEONTOLOGY OF NEW YORK. the length of the lasl three somites of the abdomen. The cercopods are curved near the 1k.sc of attachment, and have a slightly greater _th than the telson. Dimensions. The carapace of this species measures 17 mm. in length and 12 mm. in greatest width. The three somites of the abdomen and the telson have a length of 13 mm.: of this the first somite measures 1.5 mm. in length ; the second l.S mm.; the third 2 mm.; the telson to the apex of the spine 7 mm. D trihutiun. In the calcareous concretions of the Erie shales, a formation approximately equivalent to the lower Portage shales of New York. LeRoy, hake county, Ohio. EcHINOCARIS PUSTULOSA. PLATE XXIX, FIGS. '.', 10. ,'. Whitfield. Amer. Jour. Science, Third Series, vol. xix, No. 109. p. 88, pi. (unpub- lished), fig-. 7. LS80. 'ackard. Monog. N. Amer. Pbyllopod Crustacea. Twelfth Ann. Rept. U. S. Geol. Surv., i'. 451. iss;:. i ieratiocaiidse from the Chemung and Waverly groups, etc. Second Geol. Surv. Penna . vol. PPP, p. 5. 1^-1. Notes on Phyllopodiform Crustaceans referable to the genus Geol. Mag. Dec. iii. vol. i, No. 9, p. 2. pi. xiii, tig. 6. 18S4. .i . Woodward and Jones. Third Rept. Committee on Fossil Phyllopoda of I' i!:i nzoic Rocks, p. 35. 1885. uothorax small, longitudinally sub-ovate; length to width as 3 to 2. Surface irregularly convex Hinge-line short, straight, length less than ffo-thirds the length of the carapace. The anterior extremity is broken the original specimen, but judging from the position of the nodes the thoracic portion of the carapace and the indications afforded by ten edge, the anterior margin had probably about the same curvature species Echinocarii sublavis, although in the original figure it is as strongly incurving near the hinge. The ventral margin is at the posterior extremity, bending somewhat abruptly to CRUSTACEA. 179 the postero-dorsal margin, which is nearly straight. The entire margin is elevated and is especially strong upon the posterior portion. Nuchal furrow quite conspicuous, directed obliquely forward from the hinge-line. Cephalic region apparently sub-triangular upon each valve and elevated into a conspicuous node, the surface of which is covered with sharp, scat- tered tubercles. Thoracic region characterized by an arrangement of nodes similar to that observed in Echinocaris sublavis : a transverse dorsal node, just behind the nuchal furrow, directed slightly forward, followed below by a second trans- verse, elongated node, produced backward into a faintly curving ridge or carina, which becomes obsolete on the posterior area of the carapace. The postero-dorsal area is convex and relatively small. The surface of the thoracic nodes and of the postero-dorsal area is covered with conspicuous tubercles, while the remainder of the test appears to be minutely punctate or granulose. Length of the carapace 13 mm., width 9 mm. Abdomen and Post-abdomen not observed. Observations. A single valve of the carapace of this species has been observed, and, in the disposition of the nodes and ridges upon the surface, it shows a close resemblance to its associate in the same formation, Echinocaris sublavis. E. pustulosa, however, differs from that species in the less oblique outline of the carapace, and the more centrally situated lateral carina. It resembles E. socialis in its strongly tubercled surface, but the differences in these two species are readily apparent. Distribution. In the calcareous concretions of the Erie shales ; LeRoy, Lake county, Ohio. 180 PALEONTOLOGY OF NEW YORK. El HINOCARIS MULTINODOSA. PLATE XXIX, FIGS. Is, 19. ' «.W««™ ■ Nev I f Fossil Crustacea etc. A»«r. Jou, Science, Third Series, vol. xix, No. I"'.', p. 38, pi. (unpublished), fig. 8. 1880. PACKARD. The Paleozoic Allies of Nebalia. Amer. Naturalist, p. 952, fig. 10, Dec. 1882. m, Packard. Monog. N. A r. Phyllopod Crust. Twelfth Ann. Rep. U. S. Geol. Sun ., p. 151, fig. 71a. 1S83. B bcher. Ceraliooride from the Chemung and Waverly groups, etc. Second Surv. Penna., vol. PPP, p. 5. 1884. . | ,,,,. Woodward and Jones. Third Rept. Com. on Fossil PhyUopoda of the PaliEOzoic Rocks, p. 35. 1885. othorax. In the two specimens of this species which have been observed the carapace has been somewhat compressed vertically, so that the outline of the valves can not be accurately determined. It was probably much like that in Echinocaris pustuloses, transversely sub-ovate, widest an teriorly. The margins are thick and strongly elevated. Hinge-line short, being one-half the length of the carapace. On the anterior extremity the margin bends strongly forward from the hinge, rounding to a broad curve upon the ventral border; from the posterior extremity to the hinge the mar- gin is straight. furrow distinct, taking its origin just behind the second of the four nodes upon the hinge-line and passing obliquely forward, becoming obsolete at or near the anterior margin. Cephalic region obliquely elliptical on each valve, the anterior portion occu- by a large, irregularly quadrate node, whose highest point is near the binge. This is separated, by a deep furrow on its posterior margin, from a small Imt conspicuous node lying close upon the hinge. The optic spot can not be satisfactoribj located. characterized by a strong, obliquely elongate node lated upon the hinge-line and most elevated at its proximal extremity; lating in ,i conspicuous depression which merges into the nuchal irrow. The node is sub-triangular in outline and has its apex directed Below the apex of this node arises another, broad at its upper CRUSTACEA. 181 extremity, transverse and produced backward into a lateral carina which is indistinctly preserved upon both the specimens in hand, but has evidently been similar in curvature to that in the species E. sublavis and E. pusluhsa. At the posterior extremity of the dorsal Tnargin and slightly distant from the hinge is a longitudinally elongate node curving gently inward and backward, and continued into a low ridge parallel with, and, toward its extremity, merging into the postero-dorsal margin. The dorso-lateral area of the carapace is broad and evenly convex, and is separated from the margins by a wide sulcus. Surface of the carapace ornamented upon the nodes, ridges and dorso-late- ral area with pustules, which appear as strong punctae upon the cast of the ventral surface, as shown in one of the specimens. The carapace, when in an uncompressed condition, has a length of 33 mm., and a width of about 20 mm. for each valve. Distribution. In the calcareous concretions of the Erie shales on Paine's Creek. LeRoy, Lake county, Ohio. ELYMOCARIS, Beecher. 1884. Elymocaris capsella, n. sp. PLATE XXXI, FIU. 4. Cephalothorax small, siliquoid, each valve longitudinally semi-elliptical in outline, with a length equal to two and one-half times the width. Hinge- line straight, extending almost the entire length of the valves, and curving slightly downward or outward near the extremities. Anterior extremity rectangular, rounding rapidly to the broad curve of the ventral margin. Pos- terior extremity truncate and slightly incurved. Margin slightly thickened. Surface convex, elevated toward the dorsum, ventrally depressed. A faint node, which may indicate the position of the optic spot, is visible at about one-third the length of the carapace from the anterior extremity; its posi- PALEONTOLOGY OF NEW YORK. ,■[■. is more posterior and ventral than the optic node in Elymo- caris siliqua. The ornamentation consists of minute, elevated, anastomosing lines, most distinctly seen near the ventral margins. •eiinen of this species has been folded and the valves slightly irated along the hinge, the right valve protruding somewhat beneath the ventral margin of the Left. The left valve measures 13.5 mm. in length, and 5 mm. in width. Nominal and caudal parts unknown. Distribution. Hamilton group. But a single specimen of this species has , and this is from the shales above the Encrinal limestone, at the id tails of Tichenor's Glen, Canandaigua Lake, associated with Echino- punrtata, Rhinocaris columbina, R. scaphoptera, Phacops rana, Proetus macro- rephalus, Pro, tus Rowi, Dalmanites Boothi and Homalonotus Dekayi. Elymocaris siliqua. PLATE XXXI, FIGS. 5,6, cbbb. CeratiocaridjB from the Chemung and Waverly groups, etc. Second Geol. ■ .. vol. PPP, p. 13, pi. ii, figs. 1 and 2. 1884. ' - W '., i:i> and Joses. Third Etept. Committee on Fossil Phyllopoda of the ozoic Rocks, p. 3">. 1885. HALOTHORAXelongate-sub-rhomboidal or siliquiform in outline; hinge-line raight, somewhat shorter than the greatest length of the valves ; length to twice the width. Anterior extremity acutely angled, rounding raPidly '" ,1"' ventral margin, which for a short distance is nearly parallel The postero-ventral extremity is broadly rounded, the Irving thence forward, and at the hinge slightly backward again, harp angle at that point. The margin is slightly thickened and sharp carina on the anterior and ventral edges, becom- oolete posteriorly. Surface evenly convex, sloping a little more abruptly toward the hinge than toward the ventral margin. CRUSTACEA. 183 Nuchal furrow scarcely distinct, its position probably represented by tbe posterior margin of tbe cephalic nodes. Cephalic region broadly sub-triangular on each valve, its length about one- third tbe greatest length of the valve. Near the hinge-line is a conspicuous optic node, just behind which lies a low, faintly defined sub-circular eleva- tion, and below this a similar elevation, which is larger, more distinctly defined, oval or more transversely elongate. Thoracic region without nodes. Surface ornamented with low tubercles over the cephalic nodes, and with irregularly scattered pustules or granules upon the thoracic area. Fine and elevated, obscurely anastomosing lines are visible near the ventral margin and upon the dorsum, and the postero- ventral margin is distinctly crenulate. Abdomen short, composed, as far as known, of two somites, the anterior of which, in the only specimen observed, is partially concealed beneath the posterior area of the carapace. Each one is sub-cylindrical, slightly tapering and gently constricted at the margin, the latter being twice as long as wide. Post-abdomen. Caudal plate strongly elevated and wholly occupied by the base of the telson, which is short and stout and bears a conspicuous median ridge. The cercopods are flat, comparatively narrow and longer than the telson, and are minutely crenulated along their inner edges for the attachment of seta?. The surface of the abdominal somites and post-abdomen is ornamented with granules and elevated lines. Dimensions. The left valve measures 22 mm. in length and 10 mm. in width. The posterior somite of the abdomen measures 7 mm. in length, the telson 9 mm., and each lateral spine 10 mm. in length. Distribution. Chemung group. Warren, Warren county, Pennsylvania. PALAEONTOLOGY OF NEW YORK. T 11 0 P I D 0 C A R 1 S , Beecher. 1884. Tropidocaris bicarinata. PLATE XXXI, FIGS. 7-12. HKR. Ceratii icaridse from the Chemung and Waverly groups, etc. Second Geol. 1. PIT, p. 16, pi. ii. tigs. 3-5. 1884. , Rthbridgb, W( id Jones. Third Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. 35. 1885. \ chorax elongate spatulate or semi-elliptical, truncate behind ; length and one-half times the width. Hinge-line straight, nearly as long as the greatest length of the shield. Toward the anterior extremity, just in i of the eye, it slopes gently outward to form the rostral cleft, which is quite narrow. The Rostrum is a narrow, tree strip or plate, tapering to an acute apex; longitudinally arched, bearing a strong axial ridge and two lateral ridges. This body I a observed in two instances in such a position and of such form as to leave little doubt of its function. The anterior extremity of each valve is produced into a minute spine at the dorsal line; at its base the margin is transverse for a short distance, rounding in a broad curve to the ventral and posterior edges. The poste- rior extremity is broadly truncate, the margin rounding over the postero- ventral angles, curving inward toward the hinge-line, and outward at the making a minute posterior spine at that point. The margin on all ides is broadly thickened, and the marginal sulcus is conspicuous. halk region, just within the principal lateral carina, bears a strong which usually shows a minute depression or pit at its summit. Two strong carinae extend almost the entire length of each valve, the outer longer and more conspicuous, the inner usually terminating ante- dorsal line just opposite the eye, but sometimes produced to angle A low ridge extends from the eye to the anterior similar ridge is also visible in some specimens between the ina, extending tor a short distance upon the thoracic On the exterior slope of the outer carina and CRUSTACEA. 185 near the base of the cephalic region, a moderately large, semi-circular node is sometimes seen, which is more distinct in specimens where the carapace has been somewhat compressed. The Surface is ornamented by elevated anastomosing lines, which are absent on the thoracic region within the outer carina. The hinge-line and the posterior margin are distinctly crenulated. Abdomen. This part has not been found in conjunction with the carapace. A small abdomen, composed of two somites and bearing a portion of a cylin- drical telson, which was found in the shales with these carapaces, was refer- red, in the original description, to this species, and it either belongs to this form or to some species as yet undescribed. These somites are sub-cylin- drical, the first short, wider than long, and the second twice as long as wide, depressed at the anterior margins, slightly elevated and overlapping at the posterior margins, and ornamented with elevated lines similar to those upon the carapace. This specimen of the abdomen is small, and must have be- longed to an individual smaller than indicated by any carapace yet observed. Dimensions. The best preserved of the type specimens measures 89 mm. in length and 27 mm in width. The two somites of the abdomen have a length of 11 mm. of which the first measures 4 mm. and the second 7 mm. Distribution. Chemung group. In the shales associated with Echinocaris socialis and Elymocaris siliqua. Warren, Warren county, Pennsylvania. Tropidocaris interrupta. PLATE XXXI, FI(i. 13 Tropidocaris interrupta. Beecher. Ceratiocaiidae from the Chemung and Waverly groups, etc. Second Geol. Surv. Penna., vol. PPP, p. IS, pi. ii, fig. 6. 1S84. Tropidocaris interrupta, Etueridge, Woodward and Jones. Third Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. 35. 1885. Cephalothorax sub-oval in outline, reentrantly truncate behind. The right valve is the only part yet observed, and this shows the hinge-line to be straight, shorter than the greatest length of the carapace ; the anterior extremity acute, the margin rapidly rounding thence to the centre of the PALEONTOLOGY OF NEW YORK. ventral edge and passing posteriorly with the same curvature. The postero- ventral angle is broadly obtuse, the posterior margin .slightly incurved to the liince-line. The surface is evenly convex and is ornamented by a series of longitudinal carina', of which live, including the marginal ridge, extend the entire length of the valve, four of them being prominently exsert at their terminations upon the posterior margin. Intercalated between these carinse is a series of shorter and less conspicuous ridges, beginning near the anterior tremity and mostly confined to the cephalic region; one or two extend for some distance upon the thorax. The number of ridges crossing the cephalic region is eleven, one of the shorter of these crossing the eye-node. The Bingle valve has a length of 23 mm., and a width of 10 mm. Dist ibution. Chemung group. In the shales near the summit of the forma- tion, Warren, Warren county, Pennsylvania. Tropidocaris alternata. PLATE XXXI, FIGS. 14, 15. iikk. Ceratiocaridae from the Chemung and Waverly groups, etc. Second Geol. Sun . Prima., vol. I'I'P, p. 19, pi ii. figs. 7 and 8. 1SS4. 1 • Woi DWARDand Jones. Third Rept. Committee on Fossil Phyllopoda ti !' Palaeozoic Rocks, p. 35. 1885. species is represented only by impressions of two somewhat fragmentary portions of left valves of the cephalothorax. Their outline cannot be satis- factorily determined, but indications show that is docs not widely differ from of Tropidocaris bicarinata. These fragments are characterized by the is longitudinal ridges extending apparently the entire length of the somewhal interrupted and irregular in the cephalic region. These » or carinae alternate in size, the best preserved specimen showing seven whirl, the larger are finely crenulate, but no other ornamentation is I on the valve. The eye-node is distinct and is crossed by the fourth or middle carina. W;r '"!>• I" the sandstones at Warren, Warren county, Ivania. PI N AC ARI I) .]•: MESOTHYRA,* n. g. Mesothyra Oceani, n. sp. I'L \TK XXXII, FIGS 1-0; PLATE XXXIII, FIGS. 4-7; AND PLATE XXXIV, FIGS. 1-5. Dithyrocarls Neptuni, Hall. Illustrations of Devonian Fossils, pi. xxii, figs. 1-5; pi. xxiii, tig's. 1-3. 1S76. Ditkyrocaris Neptwii, Etheridge, Woodward and Johes. Fifth Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks. 1887. Cephalothorax sub-quadrate or broadly spatulate; length to width as 2.5 to 1. Surface flattened along the axial region, slightly convex and normally some- what deflected on the sides. The dorsal line is nearly straight for three-fourths its length from the poste- rior extremity; thence bending inward and again curving outward it makes a broad, conspicuous angle opposite the eye-node ; passing thence forward to the anterior extremity, forming the margin of the rostral cleft, and intersect- ing the anterior margin of the valve at an acute and slightly incurved angle. The angular extension upon the dorsal line is of the same length on both anterior and posterior slopes. On the anterior extremity of the carapace the margin is transverse for a short distance, rounding in a constantly widening curve along the ventral edge to very near the posterior extremity ; thence backward it is slightly incurved, and at the postero-ventral angle is con- tinued as the margin of a strong, sharp spine, which is directed inward. The posterior margin is transverse and nearly straight, terminating at the dorsal line in a short, sharp, posteriorly directed angle. On the anterior and * The distinctive features upon which the type species of this genus (D. Oceani) is separated from the genus Ditkyrocaris have not been noticed in any of the descriptions or illustrations of species of that genus given by English or American authors. The interpretation of the characters of the carapace, as here given, requires the removal of these forms from the family Ceratiocarid;e, and if the described species of Ditkyrocaris shall, upon reexamination, prove to possess similar features, they may all be united under the family name proposed above. PALEONTOLOGY OF NEW YORK. untero-lateral the margin is strongly thickened, on the postero-lateral roadly infolded, and its thickened edge continuous with the or .-pine. This ridge on the doublure is distinctly marked upon the surface of the carapace when compressed. _ lit 1 \- convex and bears a strong, somewhat elongate ■ le, situated just in front of the extremity of the lateral carina, and toward the dorsal line. The summit of this optic node bears a deep pit or invagination, which may have held a lense or series of lenses, or it may be of a more embryonic character in the visual organs. Upon the thoracis n is a strong, straight carina, extending its entire length. Its sides are broadly sloping, and well-preserved individuals show a finely incised longitudinal line about half way up each slope. On the inner slope, be- tween this line and the summit of the ridge, there is a series of oblique crenulations. The S is ornamented by a number of low tubercles in the inter-ocu- ;on, and elsewhere over the cephalic area by fine, elevated, frequently tnosing lines; upon the extra-carinal area these lines become longer and more continuous. Otherwise the surface is minutely punctate or iomeh composed of two somites of which the anterior was probably almost aled beneath the carapace. This somite is short, one-half as long as ind slightly elevated at the margins into articulating ridges; the somite is quadrate and somewhat longer than wide. The sur- s ornamented by strong, elevated, venate lines, which, terior joint, radiate from the crenulated margins and are directed '"' upon the posterior they also radiate from the margins but are "Wd and backward. In one specimen these lines are crossed by I wrinkle, which appear to be due to compression. •r somite bears a few low, broad tubercles. dal plate sub-triangular on the ventral surface, distinctly the anterior extremity lor articulation with the last somite; sub- CRUSTACEA. 189 pentagonal on the dorsal surface and produced into a relatively narrow telson, shorter than the lateral spines and strongly carinate along the axial line. The lateral spines are flat and long, with a low carina near the inner edge and a series of obscure, parallel ridges near the outer margin. The surface is marked by elevated lines, parallel to the margins, and simi- lar to those observed upon the abdomen, but more continuous. Strong tubercles are scattered irregularly over the surface of all the spines. A broad fimbria of setas is visible upon the inner edges of the lateral spines, and the margin is distinctly crenulate for their insertion. Dimensions. The largest carapace observed is represented by a right valve, which measures 140 mm. in length, inclusive of the posterior spine, and 60 mm. in greatest width. The smallest right valve has a length of 68 mm. and a width of 40 mm. The abdomen and post-abdomen of a large individual measure 105 mm. in length to the apex of the telson: the first somite, 16 mm.; the second, 22 mm.; the caudal plate and telson, 67 mm. The cerco- pods of the same specimen are 70 mm. in length. Observations. The character of the articulation of the valves of the carapace in this species is widely different from that in typical species of the genus Dithyrocaris. If the valves came into contact only at the apices of the con- spicuous angles upon the dorsal line a long posterior median cleft would be left between the valves with a width equal to that of the anterior or rostral cleft. Three right valves have been preserved showing this angle upon the hinge, but the only left valve observed has been broken at that point. If the process existed on both valves, as we must assume to be true in the bilaterally symmetrical carapaces, it is difficult to conceive how the articulation could have been effected by the mere apical contact of the valves at this point. Upon the right valve the angular extension is smooth near its apex, and the outer edge folded upward into a low ridge, so that it may have been slightly overlapped by and articulated to the valve at this point, but such articulation must have been quite insufficient to hold the two valves in place. With the exception of the surface about the apex, these extensions are quite PALEONTOLOGY OF NEW YORK. tubercled and thus could not have been adapted to the purpose of lation. It has been noticed in the description of the species Mesothyra i that a short distance within the dorsal margin of the type specimen, and parallel to it, is an impressed line which merges into the hinge at a point !in- in position to the angular process in this species. If this groove represents a suture or a line of symphysis, and the narrow strip of carapace between it and the dorsal line he removed, the outline of the dorsal margin of this species would be similar to that in M. Oceani. In two of the specimens at hand there is evidence, though not conclusive, of such a median strip in this species, detached from, and lying alongside the dorsal margin. It seems ■s;u v to accept the presumptive evidence of the existence of this plate in order to explain tin' mode of articulation of the valves in this species. Such n plate may have been simple, articulated on each edge with the valves, or compound, with ;i suture or hinge in the axial line, as indicated in M. Veneris. Although tlir existence of this plate has not yet been positively demonstrated, nor the necessity of its existence recognized in species heretofore referred to the genus Dithyrocaris, it must he horn in mind that the rostral plate, which presumably tilled the anterior cleft between the valves, so far as known, has not been seen in any species of the genus. It will be readily conceived that a very slight degree of maceration would I.e aufficienl to destroy the membrane holding these parts in place along the ine of symphysis, and bodies so light as the rostrum and such a median plate, would be readily transported, even in quiet water, away from the heavier por- the carapace, while members of the abdomen and post-abdomen, being i pla.e by stronger ligaments and by the overlapping slotted edges of the tin- surfaces, would naturally withstand a force sufficient to separate the parte of the carapace. • preliminary Illustrations of Devonian Fossils {he. tit.) the specimens species is founded were referred to Dithyrocaris Neptuni, on similarity apparent in many features of the post-abdominal nore careful comparison of these parts, in the Hamilton and • leaves no doubt of their specific difference. This difference CRUSTACEA. 191 consists of the following points : in M. Oceani, (a) the caudal plate is smaller, less robust, and is covered with low tubercles ; (b) the telson is relatively much longer, though not as long as the cercopods (this feature is incorrectly repre- sented on plate xxxiii, fig 7, where the telson is given about the same relative length as in M. Neptuni; at least a half-inch should be added to the length of the figure of this spine) ; (c) the carina on the telson is much narrower and more sharply angled; (d) both telson and cercopods are conspicuously tubercled, and (e) the linear ornamentation is less marked. Distribution. This elegant species is represented by portions of four cara- paces, four abdomens and post-abdomens and two post-abdomens without somites attached. All are from a single locality in the Portage group. In the sandy shales bearing Plumalina Vanuxemi, Dawson : Ithaca, Tompkins county. Mesothyra Neptuni. PLATU XXXII, FIG. 7; and PLATE XXXIII, FIG. 1. Dithyrocaris Neptuni, Hall. Sixteenth Rept. N. Y. State Cab. Nat. Hist., p. 75, pi. i, &g. C.K 1863. Diihyroearis Neptuni, Hall. Illustrations of Devonian Fossils, pi. xxiii, fig-. 6. 1876 ; not pi. xxii, tigs. 1-5 ; pi. xxiii, figs. 1-3. Dithyrocarte Neptuni, Packard. Monog. N. Amer. Phyllopod Crustacea. Twelfth Ann. Rept. U. S. Geol. Surv., p. 452, fig. 73. 1883. Dithyrocaris Neptuni, Ethkridgk, Woodwakd and Jones. Fifth Rept. Committee on Fossil Phyllopoda of the Palseozoic Rocks. 1S87. Cephalothorax and abdomen unknown. Post-abdomen. Caudal plate sub-quadrangular in outline on the dorsal side, strongly convex, and flattened above; produced into a broad, stout, relatively short telson. Along the axial line of this spine is a broad, low ridge, which runs to its apex and is most strongly elevated just behind the insertion of the spine upon the caudal plate. The cercopods are long, nearly one-half longer than the telson, flat and with a low ridge on their inner edges. To these ridges were attached the setaceous fimbriae which are faintly visible on one of the lateral spines of the type specimen. The articulating edge of each cercopod is curved upward and forward into a smooth marginal ridge, which is overlapped by the adjacent edge of the caudal plate. The surface is marked by strongly elevated, concentric, sometimes anas- 192 PALEONTOLOGY OF NEW YORK. tomosing striae, which are conspicuously angled over the median ridge of the caudal plate and pass thence backward over the lateral spines. They are nt upon the telson except near its base, and upon the cercopods are more abundant toward the outer edge, becoming obsolescent as they approach the extremities. Dimensions. The caudal plate has a width of 27 mm.; the entire length of the caudal plate and telson is 81 mm. Each cercopod measures 110 mm. in length. The individual represented by the post-abdomens must have been of great size when entire, making Mesothi/ra Neptuni probably the largest known species of the genus. Observations. The specimen upon which the original description of this cies was based is a very large caudal plate with the spines attached. It lies upon the surface of a slab of arenaceous shale, obtained in Otsego county, and i.- accompanied by more or less fragmentary impressions of four similar i lal parts and a fragment of the marginal portion of one valve of the cara- Of the five impressions two are of the ventral and three of the dorsal surface, one of the latter being the type specimen and one a fragment of a con- siderably larger individual. The slab also bears a cephalon of a young Homalo- nnlu.s Dekayi and is thus beyond doubt from the Hamilton beds. I i '1,.. preliminary illustration of the New York Devonian Crustacea (Illus- trations of Devonian Fossils, he. cit), a series of large carapaces and post-ab- domens from the lower beds of the Portage group at Ithaca, Tompkins county, were provisionally referred to the same species; in the final revision of this aterial a careful comparison of the specimens from the two localities has hown that those from the Portage group present many well-marked and ml specific features distinguishing them from the type of Dithyrocaris This latter species must therefore be considered as limited to the 'Iton fauna, and our knowledge of it is thus far confined to the specimens from which the original description was drawn. Hamilton .roup. From a loose block in the town of Plain- field, ' i countj . CRUSTACEA. 193 Mesothyra spumjEA, n. sp. PLATE XXXII, PIGS. 8, 9; an,. PLATE XXXIV, FIG, 2. Two specimens, one displaying the ventral aspect of the caudal plate and the lateral spines, the other, a single long caudal spine, show the following points of difference from either of the species Mesothyra Neptuni or M. Oceani: the caudal plate is broader and its postero-lateral margins straight : the cer- copods are broad and Hat and taper very slowly, their outer margin being thickened or carinate, and the inner bearing an inconspicuous ridge; the sur- face of the test is smooth or very finely granulose, with a few pustules and elevated strioe on the spines near the lines of articulation. The cercopods are broader and stouter than in M. Oceani and very much smaller than in M. Neptuni. In surface ornament it differs from either. Distribution. Hamilton group. From the dark shales at Pratt's Falls and Delphi, Onondaga county. Mesothyra (Dithyrocaris ?) Veneris, n. sp. . PLATE' XXXIII, FIG 3. Cephalothorax. Plight valve only known: this is longitudinally semi-ovate, widest anteriorly, and more than twice as long as wide. Dorsal line straight along the median portion of the valve, bending gently outward toward the anterior extremity for the formation of the rostral cleft. Just within, and parallel to the dorsal line, is a finely impressed line, which runs from the posterior extremity of the carapace about two-thirds the length of the shield, to a point analogous in position to the strong angle observable on the hinge in the species Mesothyra Oceani (q. v.), where it merges into the dorsal line. Were this narrow- strip along the dorsum, which is included between the hinge-line and this linear furrow, removed, the out- line of the dorsal margin would be the same as in that species. This feature has an important bearing upon the interpretation of the character of the dorsal articulation in M. Oceani. The anterior extremity appears to be produced at the dorsal line into a short spine continuous with, the carapace. The specimen is slightly fractured I'M PALAEONTOLOGY OF NEW YORK. at this point so that only the outline of .the spine can be detected. As it occupies the position of the rostral plate, there may be room for question whether this is not such a body, but with the present evidence, all indica- tions are that it is a prorate spine coalesced with the carapace and thus uecessarily existing on each valve. Below this spine the margin slopes rapidly backward to the ventral edge, along which, for a short distance, it is nearlv parallel to the dorsal line. The valve narrows backward, and at the posterior extremity the margin is produced into an acute and slightly in- curved spine, between which and the dorsal line the outline is strongly incurved. The margin is very slightly elevated and appears to be broadly infolded in the postero-ventral region, as in M. Oceani, the posterior spine being a prolongation of this infolded margin or doublure. The Surface is smooth, slightly and evenly convex. The cephalic region bears an optic, node distant from the dorsal line, and in its vicinity the cara- pace has apparently been somewhat compressed over some irregularity in the matrix. On the thoracic region is a faint longitudinal ridge, nearly parallel to the dorsal line, which becomes obsolete toward the posterior extremity. Dimensions. The single valve measures 38 mm. in length, inclusive of the anterior and posterior spines, and 16 mm. in its greatest width. Distribution. Hamilton group. In the Marcellus shales, on Mud Creek, East Bloomfield, Ontario county. DlTHYROCARIS BELLI. Dithyrocarls Belli, Woodward. Geol. Magazine, p. 106, pi. in, fig-. 5. 1871. BlOiyrocaris Belli, Ethebidgb, Woodward and Jones. Fifth Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. (>. 18S7. Tins species was described from an extremely imperfect specimen in which the valves of the carapace apparently overlap along their inner margins, only their anterior portion being retained. The drawing shows two strong carinas, but gives no indication of the hinge-line. The anterior extremity bears a short spinule similar to that in the species Mesothyra (Dithyrocaris ?) Veneris, and the surface is ornamented by abundant striae. Distribution. Middle Devonian. Gaspe, Province of Quebec. RHINOCARID^E. RHINOCARIS, n. g. (J. M. C). Rhinocaris columbina, n. sp. PLATE XXXI, FIGS. 16-21. Cephalothorax elongate-siliquiform. Surface normally arched or sub-cylin- drical, and probably somewhat flattened toward the ventral margin. The anterior extremity is slightly depressed on the dorsum and produced into a prora or rostrum, which is vertically flattened and gently deflected toward the tip. On each side toward its base this prora bears a low ridge which is con- tinued on the body of the carapace, accompanied by a faint ridge, which lies in the axial line. These ridges appear to extend the entire length of the carapace, though indistinctly seen on most examples on account of the lateral compression which has usually fractured the carapace irregularly along the dorsum. Below the prora the margin curves rapidly downward to the ventral edge, where it is nearly straight for a short distance, thence curving upward to the posterior margin, which is transverse and incurved over the axial line, the posterior extremity being thus truncate. The optic spot appears to be indicated by a faint tubercle in the cephalic region, close to the axial line. There is no evidence of a nuchal furrow, and the limits of the cephalic and thoracic areas are thus indistinguishable. Surface free of nodes or tubercles, but ornamented with faint pits on the dorsal region and on the lateral areas with fine, raised, anastomosing lines, which are sub-parallel to the margin, and converge toward the anterior and posterior extremities. In all the specimens thus far obtained the carapace L96 PALEONTOLOGY OF NEW YORK. has been somewhat distorted, and the test, which is extremely tenuous, broken by compression in the shales. A single individual shows the im- pression of the crown of a small mandible in the substance of the carapace. This organ, in every visible feature, is comparable to those already described under the species Eckinocaris punctata (page 167). The crown is curved or lunate, and bears five denticles, of which the anterior is sharp and canine- like, the posterior broader and more closely resembling the grinding surface of a molar tooth. Its length is 5 mm. A.BD0MEN. In a single example the carapace is in close association with scat- tered somites of the abdomen, of which three are detached and the fourth is in articulation with the telson. One is quite broad, being twice as wide as long and somewhat elevated in the middle, the margins very slightly ele- vated ami faintly produced in the axial line; another is relatively longer but quite imperfect; a third about one-half longer than wide, and the posterior somite twice as long as wide, and nearly cylindrical. Post-aisdomen composed of a small caudal plate, whose entire dorsal surface is occupied by the base of the telson, and is strongly elevated, the spine itself being stout and sub-conical. The cercopods, in their normal condition, are laterally flattened and slightly longer than the telson. The Sitrface of both abdomen and post-abdomen bears an ornamentation of elevated, anastomosing and slightly undulating lines, similar to those upon the carapace, but more conspicuous. These lines appear to be sharply angu- lated along the axis of each somite, and directed thence posteriorly over the lateral portions. Dimensions. All the carapaces observed are of about the same size. A well-preserved individual measures 48 mm. in length including the prora, which is 6 nun. long. The greatest width of one-half the carapace, as com- pressed, is 10 mm. Of the abdomen one somite measures 5 mm. in length and 10 mm. in width; another, 7 mm. in length and 5 mm. in width, and the posterior somite Id mm. in length and 5 mm. in width. The telson is L5 mm., and the cercopods each 17 mm. in length. CRUSTACEA. 197 Distribution. This species is represented in the collection of the State Museum by fifteen specimens, most of which are in a very fragmentary condi- tion, on account of the fragility of the test. In one locality, at the lower falls of Vinegar Brook Glen, near Norton's Landing, on Cayuga Lake, individuals have proven to be quite abundant in the shales, but arc so massed together and macerated as to be unsatisfactory for purposes of description. Hamilton group. In the shales at Tichenor's (Hen, Canandaigua Lake; near Norton's handing, Cayuga Lake, and upon the shores of Owasco Lake. Rhinocaris scaphopteka, n. sp. PLATE XXXI, KIGS. ii, 23. Cephalothorax elongate, outline as in Tropidocaris. The prora at the anterior extremity is shorter than in the foregoing species, is vertically flattened and narrowly lanceolate, slightly broadened on its upper edge toward the base. The margin curves rapidly backward from the base of the prora to the ven- tral edge, thence slightly upward to the posterior margin, which is transverse and somewhat incurved over the dorsum. The single specimen of this species which has been observed, is folded unsymetrically along the dorsum, and is laterally compressed. There are indications of a faint ridge in the axial line of the carapace, but this part has been broken along one side of that line. A strong lateral carina beginning near the anterior extremity is nearly paral- lel to the ventral margin, and becomes obsolete in the posterior region. Just above its anterior extremity on each side is a low elevation, which is prob- ably an optic node. The Surface is ornamented, on the lateral regions below the carina, with elevated lines parallel to the ventral margin, which are stronger and more frequently interrupted than in Rhinocaris columbina. The surface of the median area within the carina?, bears elongate linear nodes parallel to the axis, and several of these are visible over the surface of the optic spot. The intermediate space between the lines and nodes is minutely punctate. The PALEONTOLOGY OF NEW YORK. carapace measures 36 nun. in length, inclusive of the prora, and 25 mm. over the valve from one lateral margin to the other. Observations. Were the slender prora of this specimen broken away, Rhinocaris scaphoptera might readily be taken for a species of Dithyrocaris or Tropidocaris, for, although there is no hinge in the carapace, the normal curvature of the shield would cause it to yield along the axial line whenever subjected to lateral compression. Distribution. Hamilton group. In the upper shales of the group, associated with Rhinocaris rolumbina, Echinocaris punctata and Elymocaris capsella: Tiche- uor's Glen, Canandaigua Lake. DISCI N oi AR I DM . SPATHIOCARIS, Clarke. 1882. Spathiocaris Emersoni. PLATE XXXV, KIGS. 12-1S Spathiot arts Emersonii, Clarke. Araev. Jour. Science, Third Series, vol. xxiii. p. 477, pi. 0, figs. 1 -3. 1882. Spathiocaris Emersonii, Packard. Monog. N\ Amer. Phyllopod Cru rwelfth Ann. Rept. U. S. Geol. ., p. 451. 1883. Spathiocaris Emersoni, Clarke. Neues Jahrb. Sir Min., etc., p. ISO. 1884. SpatJiiocaris Emersonii, Ethbridoe, Woodward and Jones. Sei ond Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. 7. 1884. Spathiocaris Etnerst nii, Jokes and Woodward. Geol. Mag-., Dec. iii, vol. i, p. 34S. 1884. Spathiocaris Emersoni, Clarke. Bull. U. S. Geol. Surv., No. 16. Higher Devonian Faunas. Ontari ninty, N. V.. p. 46. 1885. Spathiocaris Emersonii, Etheridge, Woodward and Jones. Third Rept. Committee on Fossil Phj llopoda of the Palaeozoic Rocks, p. 3. 1885. Carapace ovate or elliptical in outline ; sin-race elevated and sub-conical, some- what flattened on the posterior slope, more abruptly depressed at the sides. The apex is situated somewhat anteriorly and connected by a low ridge with the inner angle of the cephalic cleft. This cephalic or rostral cleft takes its origin just in front of the apex of the shield and in uncompressed specimens widens slowly outward. In flattened individuals the inner angle and the width of this cleft are exaggerated. The surface of the shield is marked by regular, continuous, closely appressed concentric ridges, following the outline of the margin, becoming somewhat broader on the extremities and crowded on the lateral portions. At the posterior extremity the surface is cancellated by abundant radii, and similar radiating lines are visible in the anterior region along the margins of the cephalic notch. The outline of the carapace appears to vary with advancing growth, in mature individuals being nearly elliptical, but in younger specimens appearing broader at the 200 PALEONTOLOGY OF NEW YORK. anterior extremity, so that in extremely small individuals the carapace is very shmt and cordate in outline. These variations in outline have been regarded by the Committee of the British Association on the Fossil Phyllo- poda (Second and Third Kepts., he. cit.) as of specific value, but abundant material leaves no doubt that the difference is developmental and not specific. Specimens are not infrequently found folded symmetrically along the dorsum, although there is no evidence of any dorsal suture or anchylosis along that line. The substance of the test is chitinous and verv thin. Dimensions. The variation in size exhibited by specimens of this species is considerable. The average normal adult represented by the type specimen having a length of 28 mm., and a width of 16 mm. ; the smallest individual observed is 2 mm. long and 3 mm. wide. A very large fragment indicates a shield upwards of 80 mm. in length. Distribution. Widely distributed throughout the lower horizons of the Portage group as originally defined (" Naples beds," Clarke), in the towns of Bristol, Richmond and Naples, Ontario county ; Sparta and Son Yea, Livingston county; and in the upper sandstones of the group at Naples and Canadice, Ontario county ; Portageville, Wyoming county. DIPTEROCARIS, Clarke. 1882. DlPTEROCARIS PENNjE-DiEDALI. PLATE XXXV, FIG. -H. I>'l>'<- iiue-Dcedali, Clarke. Amer. Jour. Science, Third Series, vol. xxv. p. 122. %. 1. 1883. ■ is i" mm -DcBdali, Jones and Woodward. Geol. May.. Or,-, iii. vol. i. No. 8, p. 349. 1884. Dipterocaris pennw-Dtodali, Etheridge, Woodward and Johes. Second Rept. Committee on Fossil Phyl- Iopoda el' (lie Palaeozoic Rocks, p. 11. 18S4. Dipterocaris penna Dwdali, Etheridge, Woodward and Jones. Third Rept. Committee on Fossil Phyl- lopoda of tin- Palseozoic Rocks, p. 3. 1885. 'I mi: original of this species consists of but one-half or one ala of the Carapace, which is wvy elongate, with the lateral margin straight, the anterior angle nearly ninety degrees and the posterior angle acute. The area of union "isthmus," Jones) is anterior, the cephalic cleft narrow, and the margin of the CRUSTACEA. 20] abdominal cleft rapidly divergent. The surface is ornamented with concentric lines or ridges as in the associated species. This species differs from Dipterocaris Procne in its more abrupt anterior mar- ginal curvature, more anterior isthmus and the greater relative length of the abdominal cleft. The dimensions of the specimen are 50 mm. in length and 18 mm. in width to the axial line. Distribution. Portage group. In the upper sandstones at Canadice, Ontario county. Dipterocaris Procne. PLATE XXXV, F1US .'.VJ7. Dipterocaris Procne, Clarke. Amer. Jour. Sri. Mir,-. Third Series, vol. xxv. p. 122, figs. 2 and :i. IS83, Dipterocaris Procne, Jokes and Woodward. Geol. Mag-., Dec. iii, vol. i. No. s. p. 349. 1884. JHpteroearis Procne, Etheridge, W ward and Jokes. S nd Rejit. Committee on Fossil Phyllopoda of the Palseozoic Rocks, p 11. 1884. Dipterocaris Procne, Etheridge, Woodward and Jones. Third Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. ;•>. 1S85. Carapace ovate or sub-quadrate in general outline. Surface normally elevated along the dorsum and broadly rounding to the sides. Cephalic cleft very broad and short, extending one-fourth the length of the shield ; abdominal cleft narrower and longer. The isthmus or the area of the union of the alee is situated somewhat anteriorly and has a length less than one-third the length of the carapace. The angles made by the margins of the anterior cleft and the periphery are large and obtuse, the posterior angles sharper. Surface ornamented by regularly concentric lines or ridges which make a slight retral bend at the margins of the cleft. An uncompressed individual has a length of 25 mm., and a width of 19 mm. Distribution. Portage group. In the upper portion of the formation in the township of Canadice, Ontario county, and in the sandstones of the Chemung group 1,000 feet higher at Haskinsville, Steuben county. -n- PALEONTOLOGY OF NEW YORK. DlPTEROCARIS PES-CERVjE. PLATE XXXV, FIGS. 20,21. .< Ilabkb. Aiihi'. .lour. Science, Third Scries, vol. xxv, p. 123, figs. 4 and 5. 1SS3. . Jones and Woodward Geol. Mag-., Dec. iii, vol i, No. S, p. 349. 18S4. Dipt Ethbi IB, Woodward and Jones. Second Rept. Committee on Fossil Phyllopoda of the Palaeozoic Rocks, p. 11. 1884. MB, Etheridge, Woodward and Jones. Third Rept. Committee on Fossil Phyllopoda of the Paheozoic Rocks, p. 3. 1885. Carapace small, elongate-lanceolate in outline ; isthmus slightly anterior and one-fourth as long as the shield. Cephalic cleft short, margins rapidly diverging, and making obtuse and rounded angles on the periphery. Abdominal cleft long and narrow, its margins making sharp angles at the posterior extremity. The surface is ornamented as in the preceding species. Dimensions of the type specimen, length 11 mm., width 6 mm. Distribution. Chemung group. In the lower shales of the group at Dansville, Livingston county. ID IE C -A. IP O ID .A. . CARIDIDJE. PALilOPALiEMON, Whitfield. 1880. Pal^opal^mon Newberryi. PLATE XXX. FIGS. 20-23. PdUjBopalcBmon Neicberryi, Whitfield. Amer. Jour. Science, Third Series, vol six, No. 109, p. 41. 1880. Unpublished plate, figs. 1-3; also Palaeontology of Ohio, pi. viii, figs. 19-21 (unpublished). Cephalothorax elongate and slender, tapering toward the anterior extremity ; dorsum narrow ; latera narrow in front, rapidly widening behind and sloping from the edges of the dorsum in nearly a vertical plane. Margin inflected on the ventral side, slightly thickened and finely sulcate just within the edge, on the postero-lateral area rounding in a broad forward curve to the poste- rior edge, which is conspicuously reentrant. A sharp carina extends along the axis of the cephalothorax and, bifurcating near the anterior extremity, leaves a gently concave triangular area between its branches, which does not show satisfactory evidence of having been produced into a rostrum. Each branch of the axial carina connects with the anterior extremity of a dorso- lateral carina, and between this and the axial carina the surface is gently concave. The entire surface is ornamented by fine, elevated, venate, fre- quently anastomosing lines, which are more conspicuous on the latera than on the dorsum, and have a general direction upward and backward from the ventral margins. From the anterior extremity on each of the latera a fine, 204 PALAEONTOLOGY OF NEW YORK. elevated grooved line runs backward, bifurcating once anil becoming extinct before reaching the middle of the shield. The eyes arc wanting, but the sockets of the ocular peduncles are plainly discerned. The antennules are absent, the antennae being represented by two very long and large joints, which are flat on their lower surface, convex above and somewhat inflated in the middle; their inner extremities are concealed beneath the cephalothonix, but they are undoubtedly the distal peduncular joints of these appendages similar to those in some species of Crangon (C. boreas). A single joint of a maxillary palpus (?) is visible on the right side of the specimen, followed by portions of all the five pairs of ambulatory appendages. Of the first leg two joints are visible, the proximal being very broad where it disappears beneath the carapace, tapering to a narrow anterior extremity ; the distal joint is also broad, but narrower than the former; the second leg is indistinctly represented by fragments of two joints, both of which appear to have been slender; the third leg shows two joints, the proximal broad and the distal more slender; the fourth is repre- sented by a single slender inner joint, while the fifth shows three joints, all of which are very slender. The abdomen tapers rapidly toward the telson, the somites increasing in length as they grow narrower. The somites are strongly arched, the ventrolateral portions being somewhat incurved and posteriorly inclined. The basal joint of the first two abdominal appendages on the right side, and of the second and third pair on the left side are visible. The surface of the somite, though indistinctly preserved, was evidently ornamented as in the cephalothonix. The telson consists of a broad, rapidly tapering, convex spine, bearing a low axial ridge ; articulated to its anterolateral margins and to the posterior mar- gin of the ultimate somite are the compound lateral spines, which are con- nected by a membranous expansion. The lateral caudal spines are com- posed ol a shorl basal joint, sub-pentagonal in outline, the anterior margin of which is articulated to the ultimate somite, the outer posterior margin being C 'RUST 'ACE 'A. 205 jointed to the spine itself, and the inner posterior margin articulating with a flat thin lamellar spine, which lies in the middle of the membranous expansion. Dimensions. The single specimen of this species which has been observed has the following dimensions: Entire length of carapace (the caudal ex- pansion being slightly infolded), 36 mm. ; length of cephalothorax, 21 mm.; length of basal joints of antennae, as far as visible, 9 mm.; width of caudal expansion 17 mm. Distribution. In the Erie shales, at LeRov, Lake county, Ohio. :f h: izr l l o if o id j^ LIMNADIAD.'E. ESTHERIA, RttppELL. 1857. ESTHERIA PULEX. PLATE XXXV, FIGS. 10,11. EsOu Ci irke. Amer. Jour. Science, Third Series, vol. xxiii. p. 476. plate 0, fig-. 4. 1882, Estheria pulex, Packard. Monogr. North Amer. Phyllopod Crust,, p. 355; Twelfth Ann. Rept. U. S. Geol. Surv. 1883. Estheria pulex, Ethehidqe, Woodward and Jones. Fifth Rept, Committee on Fossil Phyllopoda of the Palseozoic Rocks, p. 10. 1887. Carapace minute ; outline sub-circular; beaks slightly anterior, prominent and somewhat incurved. Surface evenly and strongly convex, the most elevated point being the center of the valve. Hinge-line short and somewhat obscured by the anterior and posterior slope from the beak. The surface bears six or eight concentric ridges, which arc broad and flattened above and separated by narrow furrows. flic test is tenuous, and the very narrow, impressed interstitial furrows do not show any trace of the fine sculpturing often observed in other species of this genus. 01 this species six individuals have been observed, the average dimensions of which are \ mm. in length and § mm. in width. Five of these occur i her upon a small fragment of shale about 15 mm. square, upon which twenty individuals of Entomis, Betjrichia and Leperditia are crowded. The much, are from a thin layer in the Hamilton shales, which is extremely CRUSTACEA. 207 prolific in the remains of these gregarious creatures. Although examples of the Estheria have not proven abundant, its crustacean nature is sustained by its associations. Observations. Estheria pulex is noteworthy as being the oldest described representative of the genus and the first found in America below the Trias. In outline and surface markings it bears a striking resemblance to E. mem- branacea, Pacht, from the Old Red of Caithness, while most of the species occurring in younger rocks have the beak more anterior and the outline more nearly sub-trigonal. It is known that none of the living species of Estheria are properly marine animals, and it has been suggested in the original descrip- tion of this species that its presence in the shales of the Hamilton group may indicate the existence of pools of fresh or brackish water along the sea-shore of that period. The unusual abundance of ostracodous species in association with this Estheria furthers the probability of this supposition. Distribution. Hamilton group. In the soft shales, Miles' gully, Hopewell, < Ontario count}-. SCHIZODISCUS, n. g. (J. M. C). SCHIZODISCUS CAPSA, U. sp. PLATE XXXV, FIGS. 1-a. Carapace sub-circular or broadly ovate in outline ; greatest length along the hinge-line; greatest width just behind the beaks and slightly anterior to the tenter of the shield. When the valves are fully expanded the width nearly equals the length; normally, however, the valves appear to have been more or less folded along the hinge, and when closed were probably in actual contact with each other along the ventral margins. The majority of the specimens found have the valves in contact along the hinge-line, but expanded; a few show the valves to be laterally compressed. Surface gently and regularly convex and elevated at the beaks, which are anterior, but distant from the extremity of the carapace by one-third its -us PALEONTOLOGY OF NEW YORK. length. Their apices scarcely reach the hinge-line and are gently incurved. Toward the hinge their slope is abrupt, leaving the hinge-line slightly depressed. The posterior slope sometimes shows a low sinus as in many species of lamellibranchiata. Hinge-line long and straight, extending the entire length of the carapace and showing no articulating teeth or ridges. The ventral margin is gently recurved and scarcely thickened. Surface ornamented by continuous, concentric, sharp ridges, which are closely crowded near the apices and more distant on the posterior portions of the valves. Of these ridges, twenty-five may be counted in a full-grown individual. Dimensions. Considerable variation in size is noticeable in the specimens at hand. A mature individual has a length of 15 mm., and a width of 13 mm.; the youngest example a length of 4.5 mm., and a width of 4 mm. Observations. This unique species in outline and sculpture presents a striking similarity to species of the genus Aptychopsis. It lacks, however, any evidence of a rostral plate and of any anterior cleft for the reception of such a plate. Its affinities are evidently with the genus Estheria and Leaia, as is shown by its umbonate valves, but it differs from the former in its remarkably elongate binge-line, absence of the characteristic surface ornamentation, and from the latter in outline, and in the absence of the posterior ridge. It may, therefore, be regarded as constituting a new generic type of Phyllopod Crustacea. Distribution. Hamilton group. A number of specimens of the species have been obtained, all from a single locality, in the limestone at the base of the Hamilton shales near Centerfield, Ontario county. CIRRIPEDIA. BALANID.l'. P II 0 T 0 B A L A N U S , n. g. (R. P. Whitfield). Protobalands IIamiltonensis, n. sp. (r. p. w.) PLATK XXXVI, FIG. 23. Shell small, ovate in general outline, narrowing toward the carina] extremity ; surface depressed-convex, most elevated at the apex of the carina ; composed of twelve peripheral plates. Carina sub-semicircular in peripheral outline, conspicuously elevated to an obtuse apex, which lies just within the proximal margin of the plate; regularly sloping on the anterior surface, but slightly incurving or concave upon the sides. Rostrum short, posterior margin broadly curving, apex scarcely elevated. The lateralia, which are regularly disposed in five pairs, are symmetrical, and of the same general elongate, triangular form and of nearly the same size, the anterior members being somewhat the larger. The .apices of these plates, as far as preserved, are slightly elevated and elongated in a short ridge toward the axis of the shell. All these plates are marked by low, radiating ridges, which become obsolete before reaching the apex. Of these, twelve may be counted upon the carina and six or eight upon the rostrum ; on the lateralia. they vary in number from four to seven. The radial areas are conspicuous and, as far as can be discerned, smooth. A portion of the 210 PALAEONTOLOGY OF NEW YORK. type specimen has been broken away, removing the summits of the posterior plates and covering the spot where the scutum and tergum would normally lie. The specimen, which retains the replaced substance of the original shell, shows an expanded margin about a portion of the periphery, and this prob- ably represents a portion of the edge of the valves which has been flattened and creased by compression. Dimensions. Length 4.5 mm., greatest width 3.5 mm. Observations. This minute species is the only known representative of the Balanoid cirripeds in the Palaeozoic rocks, with the exception of Balanus carbo- narius, Petzhold, from the Carboniferous rocks near Dresden, Saxony (Neues Jahrb. fur Min., etc., 1842). Protobalanus, however, differs essentially from other forms which are included in the order Balanidcz in its great number (twelve) of plates, the usual number being six, four or one. This fact is not without significance, as it may indicate a --eater specialization and a higher degree of structural development than in the other fossil and recent species of this order. Distribution. Hamilton group. In the Marcellus shales: Avon, Genesee county. P A L M 0 C R E U S I A, n. g. (J. M. C). Pal^ocreusia Devonica, n. sp. PLATE XXXVI, FIGS Jl 6 Capitulum ovate iii outline, patelliform ; length to greatest width as 5 to 4. Surface gently conical, slightly depressed on the posterior slope. The apex is truncated by a horizontal plane, forming a relatively large central aperture bavin,-; approximately the outline of the shell itself, and a length equal to one-third thai of the shell. The substance of the shell is apparently thin; its surface marked by faint radiating striae or elevated lines. There is no apparent evidence of the separate original plates, all having been coalesced into a single external CRUSTACEA. 211 plate as is characteristic of the genus Creusia. A single conspicuous furrow, slightly within and concentric with the margin, may indicate the line of contact of the capitulum with the walls of the basis. Basis tuhuliform, sub-cylindrical or cup-shaped. The specimen is attached to a colony of Favosites hemispkericus and has at some time been overgrown as far as the aperture by the multiplication of the cell tubes. A portion of the coral was subsequently removed by natural causes, exposing the capitulum, but leaving the tubular basis completely enveloped. The surface of the former still hears traces of the cell walls of the coral. By removal of a portion of the coral near the side of the specimen it is found that the internal cavity is partially filled with soft decomposed chert, the remainder of the cavity filling, the capitulum and the entire coral being silicified. The internal plates, scutum and tergum, are not preserved. Dimensions. The capitulum has a length of 10 mm., and a width of 8.5 mm. The depth of the tubular basis can he measured through the aperture for 8 mm., but is probably somewhat greater. Observations. This interesting species brings to our knowledge a representa- tive, from Devonian rocks, of forms included under the recent genera Pyrgoma and Creusia, neither of them previously recognized in palaeozoic formations, and the latter not heretofore known among fossils. Features of distinctively generic value in which this species differs from recent members of the genus Creusia are not readily apparent, and, therefore, the term Paltzocreusiti is used tenta- tively to express the probability that such differences will eventually he found. Distribution. Corniferous limestone. LeRoy, Genesee county. I. i; PA 1)1 DJE. STROBILEPIS, n. a. (J. M. C). Strobilepis spinigera, n. sp. PLATE XXXVI, PIGS. 20-22. \ SPECIMEN from the soft shales of the Hamilton group, in a fair state of preservation, presents features whose homologies are not at present well understood and do not permit a satisfactory interpretation of their taxonomic relations. The specimen itself is here described as it appears, and this descrip- tion must serve temporarily as the diagnosis of the species: The capituujm consists of a conical terminal plate 5 mm in height, having a nearly circular base, 10 mm. in diameter, against which lie the final plates of three vertical ranges, one at either side and one in the middle of the speci- men. Of these three ranges, the plates composing those at the sides are of about the same size, while those on the central range are much smaller. All these plates have, however, about the same general trihedral form, but differ somewhat in details. The first plate in the left vertical range is abruptly truncated on its anterior margin, from apex to base; from the apex backward sharply angulated and sub-carinate near the apex, becoming broader as it approaches the margin. This plate is quite unsymmetrical, its outer lateral slope being broad, equi- lateral, or gently concave ; the inner slope convex, very narrow, angulated by three radiating ridges, the middle one of which is the strongest. The second plate of this range is narrow and sellate, the antero-lateral slopes being concave, and the apex overarching. The posterior portion is angulated, without carina, and is broadly curved, making a moderately sharp ""-1'' with the antero-lateral faces. This plate is nearly bi-laterally symmet- CRUSTACEA. 213 rical, the outer portion of the posterior slope being a little more convex than the inner. In the third plate the form is much as in the preceding, but is broader, the apex more central and not so strongly incurved, the antero-lateral slopes more conspicuous and the posterior -lope narrow and unsymmetrical. The fourth plate is almost the reverse of the first in form; the posterior area is abbreviated, very narrow and slightly concave just beneath the elevated apex; the outer lateral slope is broad and flat. Whether the plate bears a median carina and differs as widely in the size of its lateral laces as in the first plate, cannot be determined, as it is largely covered by the preceding plate of the range. The fifth plate is broken and its form cannot be satisfactorily determined. In the right vertical range the plates were evidently symmetrical with those of the left, but have been somewhat displaced from their normal position. The first is in place: the second has been pushed out of its place and is not apparent, unless it is represented by the upturned lower surface of a plate visible near the lower portion of the specimen lying beneath the other plates ; the third plate is pushed backward so as to show the strongly carinate anterior surface of the fourth plate projecting beyond its anterior edge ; beneath this lies also the anterior edge of the fifth plate, showing that it also is carinate ; and back of them all lies the sixth plate with a posterior apex, truncate behind, lateral slopes broad, the outer being the broader, and separated from the inner by a carina. Although this plate does not appear in the left range it may be represented by a fragment lying beneath the inner edge of the fourth plate of that range. The axial range is composed of small plates having about one-third the diameter of those of the lateral ranges. These differ considerably in form, but appear to be bi-symmetrical. Three are to be seen in juxtaposition on the anterior portion of the specimen, and a fourth is displaced and lies be- hind the inner posterior edge of the fourth plate of left range. In addition to these three ranges of plates is a vertical row of spines, which, whatever their normal position, lie in a more or less detached condi- 214 PALAEONTOLOGY OF NEW YORK. tion about the right and lower edges of the specimen. Sixteen of these spines may be counted, the first eleven lying regularly one below another along the edge of the terminal and first right lateral plates, and increasing in size downward. The remaining five are larger and detached, but still showing a degree of order in their arrangement, their bases all directed inward about the lower margins of the specimen. These spines are about four times as long as wide, the first ten deeply grooved on their exposed surface, the last six apparently turned over, showing a surface sharply carinate on the axial line and grooved within the margins. The position of this range of spines was in all probability opposite to the axial range of small plates, and the pressure, to which the specimen has been subjected in the shale, has displaced it by pushing it around to the right without scattering the spines to any- great degree. The plates and spines are calcareous, with a strongly punctate surface, and more or less distinct concentric growth-lines, which in the broader plates are crossed by low, radiating ridges and furrows. The basal edges of the plates are thick and crenulated on the under side. The species thus appears to have been composed of four vertical ranges, three of plates and one of spines; of these the two larger rows of plates were in themselves asymmetrical, but were symmetrical in position, number and form; the third row was made up of bilaterally symmetrical plates, themselves symmetrical in position with the row of spines. All these range- overlapped or were terminated by a conical plate. Dimensions. The terminal plate has a diameter of 10 mm., and a height of •) mm.; the elevation of the apex is slightly more than this in some of the other plates, and the width of the plates in the lateral ranges varies as pointed out in the description. The smaller plates have a diameter of 4 or 5 mm. : the spines a length of from 5 to 8 mm. The entire animal must have been between 25 and 30 mm. in length. Observations. In the species of Turrikpas (T. Wrightianus), figured by H. Wood- ward (Quarterly Journal Geol. Soc, vol. xxi, 1805), and of Plumulites given by Barrande (Syst. Sil. de la Boheme, vol. i, suppl., 1872), the number of vertical CRUSTACEA. 215 ranges of plates appears to be a matter of uncertainty and probably also of variation. Turrilepas Wrightianus, l>e Koninck, has tour ranges ami Barrande has expressed the impossibility of ascertaining from his specimens of Plumulites the exact number of these rows, regarding it as not less than lour and rarely so few. In Lepidocoleus, Faber, there appear to be but two ranges of plates. In none of these genera has the character of the upper extremity of the animal been ascertained. Sirobikpis spinigera may present a similarity to Turrilepas (Plumulites) in the numerical arrangement of its parts, but it presents an association of characters which separate it from either of those genera. In recognizing the cirriped character of this fossil, it is difficult to conceive how such a body, capped at the anterior extremity by a circular conical plate over which the adjacent plates are lapped, could have served as anything but the capitulum of the animal. There is no such difference in the character of the plates as would allow some of them to be regarded as peduncular and some as capitular, and no evidence that any scaly peduncle was attached beneath the plates. On the contrary the whole association of plates appears to represent a simple and uncomplicated primary type of lepadiform capitulum, less condensed and modified than in recent representatives. Scalpellum, Lepas, Ibla, etc. Distribution. Hamilton group. In the upper shales near Menteth's Point. Canandaigua lake. TURRILEPAS. Woodward. 1865. Turrilepas flexuosus, n. sp. PLATE XXXVI, PIC 1. A SINGLE minute plate is characterized by the following features: Outline obliquely lanceolate ; nucleus apical ; a longitudinal furrow, lying just behind the middle line of the valve, begins at one-third the distance from the apex to the basal margin, becoming broader and deeper as it proceeds, its slope on the anterior side being much stronger and more abrupt than on the posterior. 216 PALEONTOLOGY OF NEW YORK. Surface ornamented by elevated lines, which are transverse and closely crowded near the apex, becoming strongly lamelliform and bent downwards over the longitudinal furrow, those toward the base not crossing this depres- sion. Where thus interrupted the lines have multiplied more rapidly than mi the anterior portion of the valve. Length of the single plate 2.5 mm., width 1.5 mm. Distribution. Upper Helderberg group. Corniferous limestone : In the boulders of decomposed chert, Canandaigua, Ontario county. TURRILEPAS CANCELLATUS, n. Sp. PLATE XXXVI, FIG. 2. A single plate is characterized by a few distant elevated concentric lines, crossed by fine, closely crowded, interrupted, radiating lines, which are more elevated and more conspicuous toward the posterior margin. The valve appears to be sinuous medially and is abruptly deflected to the left antero- lateral margin. The specimen is small, measuring 2.5 mm. in height and 2 mm. in length. Distribution. Upper Helderberg group. Corniferous limestone: In the decomposed chert, Canandaigua, Ontario county. TURRILEPAS DEVONICUS. PLATE XXXVI, FIG. 3. Plumulites Deixmwus, Clakke. Amer. Jour. Science, Third Series, vol. xxiv, p. 55, figs. 1 and 2. 1882. Tin; plates of this species appear to be of two forms; one elongate-sub- triangular ami leather-like, the lateral margins curving to the nucleus, which is apical, basal margin terminal, surface flat except for a rounded median ridge extending from the apex to the base, which becomes wider and stronger with ch increment of growth along the margins; concentric growth lines elevated, moderately distant, curving upward and closely appressed. The other form is broader and oblique, with sub-equal, convex margins, and sub-apical nucleus, CRUSTACEA. 217 and without the median ridge. These different forms of plates have been found in close proximity leaving little doubt of their coherence in the same individual, probably being from separate vertical ranges in the composition of the capitulum. The elongate form finds a close parallel in some of the Bohe- mian species, as Plumulites Bohemicus, Pl.frate.rnas, PL compar, Barrande, although the latter attained a considerably greater size, and it appears probable that the broader plate here described is homologous with the plates termed by M. Bar- rande the valve frnesln'e, found in association with the plumate plates in well- preserved specimens from the etage D. This plate was however regarded by Barrande not as a member of a range of similar plates but as isolated among the other plates composing the capitulum. The scales of Turrilepas Devonicus are small, the elongate form measuring 3.5 mm. in length and 2.5 mm. across the base, the broader form 2.5 mm. in length and 2 mm. in width. Distribution. Hamilton group. In the shales and limestones near the base of the Hamilton shales : Canandaigua and Centerfield, Ontario county. Turrilepas squama, n. sp. PLATE XXXVI, FIGS. 5-8. A few scattered plates exceeding in size any belonging to the associated species appear to represent a distinct form. These are broadly sub-triangular, having a width nearly equal to the length. The best preserved examples are valves fenestrees, having the nucleus sub-apical. The earliest of the concen- tric striae are nearly circular, becoming sinuous, more transverse and more closely crowded near the basal margin. Along the posterior margin the striae present the appearance of being " gathered," but they become obsolete before reaching the anterior margin. The surface is nearly flat, with indications of a low sinus near the middle of the valve and toward the posterior edge. The other plates referred to this species have the same general form, and the nucleus apical, one of them being abruptly deflected toward the anterior margin. They all agree in the character 218 PALEONTOLOGY OF NEW YORK. of their sculpture which consists of fine incised lines separated by broad, re- trallv sloping annulations. This ornamentation is noticeably coarser than in any of the associated species. Their size varies from a length and width of 4 mm. to a length of 6 mm. and a width of 5 mm. Distribution. Hamilton group Centerficld and Canandaigua, Ontario county. TlJRRILEPAS NITIDULUS, 11. Sp. PLATE XXXVI, FIG. 4. A single plate wanting the nuclear portion is distinguished from the asso- ciated forms by its very line and closely set concentric striae, and its broad posterior area, which is covered with conspicuous pits or punctoe, apparently arranged also in concentric lines. The basal margin is gently sinuous, corres- ponding with the sinuous concentric lines, and a broad low sinus is apparent over the median portion of the valve. The length of the specimen is 2.5 mm., and the height about 2 mm. Distribution. Hamilton group. In the lower shales at Fall Brook, Hopewell, Ontario county. TlJRRILEPAS FOLIATUS, 11. Sp. PLATE XXXVI, FIG. 15. A single plate has an elongate semi-lanceolate or semi-saggitate outline, and a length equal to three times the height. The nucleus is not distinctly seen in the specimen, and the concentric lines in its vicinity appear to be obsolete, but further downward are closely crowded and clearly defined. The posterior margin is long and straight, appears to have been slightly elevated or thickened and possibly folded. The anterior margin seems to have been abrupty curved across the plate, rounding backward to the straight basal margin. The height of the plate is 2.5 mm., its length 7 mm., and the distance along the posterior margin 9 mm. Distribution. Hamilton group. In the limestone layers at the base of the Hamilton shales: Canandaigua, Ontario county. CRUSTACEA. 219 TtJRRILEPAS TENER, 11. Sp. PL \ 11: xxxvi. i To this species are referred certain plates which have the same general out- line ami surface features as in all the other specimens observed. One fragment of shale retains ten of these plates over the surface of a square inch. The out- line is equilaterally triangular and the surface nearly flat : the nucleus apical ; the anterior and posterior margins straight, diverging at an angle of seventy-five degrees: the basal margin is gently sinuous, curving upward toward the poste- rior, and downward toward the anterior margin. Along the posterior margin, the plate is abruptly deflected toward the opposite side, but this is only tor a very short distance. When the plates are not flattened there appears to be an elevated fold or broad ridge, situated in front of the axial line of the plate, running from the apex to the basal margin. The concentric striai are tine, ele- vated and crowded closely together, becoming obsolete just before reaching the anterior margin. As in other forms of this genus, these lines curve upward at or near the anterior and posterior margins. All the specimens observed have about the same Length and height, which is 3.5 mm. Distribution. Hamilton group. In the lower shales at Centerfield, Ontario county. TURRILEPAS(?) NEWBERRYI. PLATE XXXVI. FIGS. 16-19. Plwmidites Neibberryi, Whitfield. Annals New York Acad. Sciences, vol. ii, No. S, p. 217. 1 S82. Plumviites Newberryi, Whitfield. Pal. Ohio. vol. iii. pi. viii, figs. M 3 I- - £ i rH , > — 1- = ~* — ~_ M /' " - s> — oq m > i-h 2 ^ -• •_- M 1 -r :: — > ■- x'-.. . - — — ■ -r - 7 -:- • •-■•■ fUO.IOJUl.10f> * ~ 1 .... -■-■ • ■auuqoqog * - - aiu:>(-!.i, » vf • - - 3t • .' ~ 7. :- . . . T . ME AND AUTHOR. < h CQ O -J < 3 C rn c z 1 5 Z 1 1 I $6. > z R ; R : ? s / 0 - — — i " - i - — ; -' / — -- - ~ -.= " X . ./ -■ I - p £ _~ u C § 111 ~- - ~ - "S ■ = a § s3 „? a - ■ — = r ■ . _■ "_ ■ ' .j: - r '■ . = " • "g.s I IllJll • ;-J-j|fi: a PL, pq W BWc O O ^ - K "_ < h W / ■3 n X ~ J: - - 9 -* c3 - — ; - ' - - *— "^^x— - • ' ^^ ^^^^—. — ■' ■• — ^y c o - SB - ■- fc i-li-^-- - ^^^ ::::::::: — _ ■M — 71 CO ^ -* HOM^l »" — r — ~1 M -r i" x i- x ~. o -h m Maqcutix SDToads \iaqumx l^UDS Tl M T»» ir: *x> t- cc cs c- t-H — Tl W rH rH i-H ^ o -^ r« co ci o - oi 224 PALAEONTOLOGY OF NEW YORK. E ■a « XI / 71 Tl^rH — in ci I l-1 io X ci 1 XI <*>A •" n e >>> XXX -9 3 i - i i^ I H CM H W l> H ^ -4" -3 pq M B cq I-- — l I— ( I— I H- ( I— 1 h— I X X X! X X tt X t^ t— 1 . X X X ~s OS tc fi OS — * i-H HH 1— ( •— xxxxxx xxxxxx '_ I w - ******* oi.iiHioqoy -H * * aui:>[si.io L a « fc « t ; — * . • s=s" " 6 'S ' a; :I1 - .- £ 3 S c bl o i- '/. M >. GC - ~ ~ B B M-3' '" 9"g g§ -a S Pi B >. ; - T3 ' "3 E 2 K i § § i hS da; 6^1 so 1 T I - -r — — — . — & — C- ■ — — i O o c coo ■ B B — -— B B ~ _a ■a a S«i^3 S 53 rta 3* if 3 — — "S [u^ P< o - .^ pr *S . S>a 4 s ^h.x >« r± B — ^ — ^~* :2 ~t^ rt C3 Q g 7) O "B _ r— -~1 c c - - - OOOODQ O ODO coocaccDD o dod u ^B , 2 £ o OiS ^ 5 oj J J J J yj >j J J ® B3 bo cj 'S 93 00 ca * ?5 o 03 _- a is • .-a 03 3 be B 03 bo f a :"£ | bp'| CL| (^ cu (X (X pu i C " | , — ?1 M ^ »- iD t^ x-^ oi ro ^ ii to .I0(|U1I1\ Kfi^-: I- / ~. c ~ iM -I Tl 71 71 71 71 71 77 :'. 77 CRUSTACEA. 225 x X X X c ~ A — SI — . — X - - G S X S M K CT ■-.. snojajituoo * z * * * ■ CO ****•• ~ •ai.reqoqag * l~ * • • • - iun^suo . . . o a < s i5 = X - it < / S — 1 c o ; ;s | . £ - " ^~ ~ ™ •"5 .• — S> i • "E • ■ ~ ? — '■ ~~ V - - s"_r - ■ ■ *- "^ c "=5 "s — ' "". / rr' g, . ~ ^ r. a *2 - ■ - -*• u ;■ ■■*-. Q d w *_ d C C . . . . s ... . . . _• ■~='=::^_- = .I_-^ » . = s_-_-i ;J aj :J ;_' :.' z.' ;-' z. x zl zl z- zl — ' zl zl i.' — ' zi — X BO — El jaqranx saiaadg i>oo o» o ih « oo ■«* i- co r- oo as o -* ca co •<* ■". ■- ~ — ri se -r q - :i n T i* - C- X — jaqmn\ isuas e«eo^«iosot^aDc&OT-cc>«PE-c- 11 CD -v m t— r- c- t- ■z t- X r. i — *i CO I, t, c- ,, , 226 PALAEONTOLOGY OF NEW YORK. 9 — 5 XXVII. 1, 2. XXVII. :.. J XXVI, XXVI a, 1-3. XXVII. 7 J. XXXI. 1 XXXI, 3. XXXI, 2. XXVII, 10; XXVIII. 1-7; XXIX, 1-8. XXIX, 20, 21. XXIX. 14-17. XXX. 1-12. XXIX. 11-13. XXIX, 9, 10. XXIX, 18, 19. XXXI. 4. XXXI, 5, 6. a re :o co i-i o TO Tt< ir: tc :i m -f to r/i o *-. im in *.^ iC C-l to yc> 33 :D CO l~ I- L- l~ I- CO CO CO J- — rt ~ * ^ k f 3 £ . Psf v S-s Kl « S 3S.5 v?~S-r^ i-TJi>:-:5 g- -■ * S' D -s- S'S2 = ^ c £ --.= - s-§vg^3 i"3-S o~ 2 SI id ~: ::^ J ^'^11 ■3§glg;Sll g | J" 'H- *1" M ~ ~ ' J - Tl TO |AH;iJ!*e-il- 5grH(M ■.IOr,u,.ls-.,l,.„U ,H rt rt rt H * MOqttm^ ibt.ios -^ \n -oi- co cr. o .-h ?i to ~f ir; to t- ao os co co co oo co co as cr. cr. cr. cr. cr. oi as cr. as CRUSTACEA. •2-11 Plate and Figure. XXX. 24, 25. XXXI, 7-12. XXXI, 13. XXXII, 1-6; XXXIII, 4-7; XXXIV, 1-5. XXXII, 7; XXXIII, 1. XXXII, 8, !t ; XXXIV, 2. XXXIII, 3. XXXI, 16-21. XXXI, 22, 23. WW, 12-18. \ \ \ V. 24. WW, 25 27. W \V. 2(1.21. XXX, 20-23. WW, 10, 11. -~ ~z ■ t- ir. i- — w oa t l~ i~ — c — *i re o M £-cc x x - -. c-. — . a r. os o o o o = X — — I Hn — ?l ?l Tl Tl ?1 M •! ■ 1 •88BIJOJ . . . j * . . . . j w . . j *!„**. M * | iH •! UOJIUUEH * ' * 1 " * * • * 1 00 * * 1 " o «- •JoquinK satoods jaqmnn isuog ! o — ;i rsiriri^r- cc c: o — r-ir: GOO OOOCO OO — i r-i ■*T IC 228 PALEONTOLOGY OF NEW YORK. 6 1 En ■3 = XXXV, 1-9. XXXVI, 23. XXXVI, 24-26. XXXVI, 20-22. XXXVI. 1. XXXVI, 2. XXXVI, 8. XXXVI, 5-8. XXXVI, 4. XXXVI, 15. XXXVI, 9 14. XXXVI, 16-19. r- as © ci in c b t- x co os oi :£ o O — — _ „ _ ^ , , _ „ CI CI CI CI CI CI CI CI CI CI CI CI a. 73 - 6 1 ij •33S3U30 < U01IUUlt|t H i-3 * | "> ■ I • 1 * 1 " •■**'*»*■ 1 13 < - - w .\iii:-)-i.ii i • i • i • i • • i i 03 P Erf Q r— O go s Erf -- GO ■< ■< as Ed 55 Erf C5 • -h iQcnsooonh • — • t~ — co ■ t-h • :i m cc /. z x k K • m • in —to •sno.iajiuoqatto -r -£.i3q.iop[OH o i— < "K.lttSBJtf ^i i—i .c o s p -. g "3.2 OK _' n .J - S,2'M .j§,~ _ = >-. - to it~ 7~ -" °" .£ 3 3 m d *- X — 'x i. 32 W Cfi Cft DO X ^ 02 -— S — : - - — — - g ,2;2 - » b -■' £•=■ £ s g x = " r x i c j J£ — '- ^ :"o3 :« ^ -3 3: r** ~ - i ^3 J _: J £ £ £ oft ia^ .idqumx lB!-laS 230 PALEONTOLOGY OF NEW YORK. SUMMARY OF THE NORTH AMERICAN DEVONIAN CRUSTACEA (EXCLUDING OSTRACODA). - « NAME. i cJ 3 3 o y ti « to 3 o 0 O a Corn Marc Hami Tully Gene © u 1 1 Calymene, .... 1 1 II 2 Homalonotus, . i 1 1 III 1 Bronleus, .... 1 PV ti Phacops, .... l i 3 ( 1 3 i V 25 Dalmanites,. D. (Hausmannia), i i IS 1 1 5 ? 1 — VI 4 1 i VII 3 D. (Coronura), i 2 VIII 5 D. (Cryphseus), . 2 ? IX 4 D. (Odontocephalus). 4 X 2 D. (Coryeephalus), 1 XI 6 3 D. (Chasmops). Acidaspis, i ! 5 2 XII 1 XIII i Lichas, .... 7 XIV 1 L. (Terataspis), . 1 XV 2 L. (t lonolichas;, i 2 XVI 1 L. (Hoplolichas), . 1 XVII 1 L. (Arges), 1 Will 2 26 L. (Ceratolichas), Proetus, .... 2 — XIX 1 11 9 ? 2 XX 4 Phaethonides, . i L 3 2 1 \\l 8 83 Cyphaspis, .... (Total Trilobita), . . ] 4 3 • 0 1 1 2( ) 49 24 5 0 2 0 Wll 1 Protolimulus, 1 XXIII I Eirrypterus, I XXIV 2 Stylonums, . 1 XXV 3 Ceratiocaris, . 2 \\\ 1 7 Echinocaris, 1 4 2 B xxvi] 2 Elymocaris, I 1 XXVIII 2 Tropidocaiis, 1 2 WIN 4 Me i thj )■:>. 2 1 XXX 1 Dithyi'ocai-is, 1 :• :xxxi 'J Rhinouaiis, 2 XXXII 1 Palaeopatemon, . 1 \ \ XIII 1 Spathiocaris, . 1 XXXIV 3 Dipterocaris, 2 0 XXXV I Esthei'ia, . I WW 1 1 Schizodiscus, 1 XXX\ II 1 Protobalanus, . W \ VIII 1 Palaeocreusia, 1 XXXIX 1 SI robilepis, I XI. s Turrilepas Total ' 2( 2 5 40 12 1 12 126 ) 52 7 I I INDEX TO THE GENERA AND SPECIES DESCRIBED OB NOTICED IN PALAEONTOLOGY OF NEW YORK, VOL. \ II. (CBUSTACEA). The heavy-faced numbers denote the place of description.] (27m numerals in parenthesis haw referenct totht Synopsis of Genera in th Introduction to this Acantholoma, . Acantltopyge \» li>\M-ls. Murcliison, callicera, Ball, I>ulVesnoyi, Barrande, . n sp., Hall, lioinmgeri, Hall. . sp , Hall, tuberculatus, Conrad, [Terataspis), (Terataspis) Eriopis, Hall, |7'. ) grandis. Hall, IT. )sp.?, Hall, . A \ A \ A \ A- A. A A A^onia, .... Ampyx, An rcHOPSls, Barrande, \l.l 11 I "I ii- v - , Arctinurus, Argas, Scouler, AKGES, Gold/uSS, A. arnmtus, Gold/uss, \ sisTuzok, Barrande, A. bisulcata, Barrande, A. memoranda, Barrande, A. regina, Barrande, Asaphus, . xxiii, xxv, xxix, xx\ xxxvi, : A ? acantholeurus, (Conrad] Hall, \ acanlhopleurus, Conr«d, -4 ? acanthopleurus, Conrad, . A. aspeclans, Conrad, A. aspectans. Conrad, a ? denticnlatus, Conrad, A ? denticulatus, Conrad, A. Hallii, Conrad, . A. laticostatns, Green, A. lalicostatus. Green, .-I. myrmecophorus,ijre^n, . A. pleuroptyx. Green, A. selenurus, Eaton. . A. Wetherelli, Green, A. (Illcenus), Dalman, A. \Olenus), March ison, . A :l'ro,tus> Stoketi, Murchison, Asmusia, .... A*PIDOCAR[S. Iteuss, Aspidolites, Asleropyge, Bactropas longipes, Barrande, Balnnus carbonarius, I'etzhold, p Veil 1' Mil. WW IfEl RII 111 V. . 2011 \\\\ 11. xl Brongniarlitt, X \ i V (xxxM 69, - > 76 Brontes. \\\ . wvi w i. wii, \\ iii G9 , 71 BRONTEUS, Gold/uss, . \\'. wvi, 12 72 Ii ncnnthopeltis, Schnur, . 13 xvii 84, 85 It. Barrandii, Hibert, 13 xviii, 71 r. clementiuns, Barrande, . 13 71 li. grannlatos, Gold/uss. 13 7" B. Raphael], Barrois, 13 xxx viii B. thj sanopeltis, Barrande, 13 77, 7S 1!. Trutati, Barrois, . 13 73 B. Tolling, i/n«, . xix, Vi, 13 7S B. Waldschmidti, ro/t Kuznen, 13 . xli. xliv B. [Brontes), x\\ xxxvi I'.I.Mil >ES, . . . . . xlix Ii\. lx. •OS Burmeisteria , xxiv lxi\ I't i.v m ink, Brongniart, xxvii xxxvii C. anchiops. Green, ."■9 lvii c Blumcnbachi, liroiujniart , 4 \w , xxxvi, (xl] S3, M c. bu/o, Castelnan, 27 84 c. bufo, Green, . xii. 21 liv h c. bu/o. Green, 26 liv c bu/o, Hall. 19 lit c. bulb, var. rana. Green, . xii. 24, 26 liv h c. bu/o, var. rana. Green 19 x. xxxii, \xxiii, xxxiv, c. crassimarginatus. Hall, . 99 X\X\ il. \\\i\. xli xlv ( macrophtalma, Brongniart, . xi, 63 37 C. mac rophthalma, Murchison 63 3!l C. marginalis, Conrad. . 122. 123 37 c. marginalis. Conrad, 122 xii :; ; C. Niagarcnsis, Hall, 4 33 c. ? oilontocephala, Green, xii, a2 3B c. ? odontocephala, Green, 49 3: c. platys. Green, . . xii, xvi, xvii, xviii, 1 42 c. platys, {screen) Hall, . 1 03 c. platys. Hall 1 59 c. Jlowii, G ret; n. . 119 37 c. senaria 23 28 (J. spectabilis, Angelin, 4 49 CARKIOCARIS, Woodward, . lix, Ixi 03 C. lata. Woodward, lix x\\ C Kcenicri. Woodward, lix \\\ Celmus,' . xlii. \h xlvi • grannlatns, Angelin, xlv l\i. Ixii CERATIOCARIS, HfcCoy, . (Iii) 163, 164, 171 lix C. armalns, Hall, 170 xxix C. armatus, Hall, . . 166 xxxil c. Beecheri, Clarke, . \\, 1cari$ i.lristozoe), C. [Aristozoe) punctatus, Hall, C. (Colpocari$\, . C. (Leptocheles), Ceratocephala, CEH v TOUCH \-. //.;/;. frraltrus, .... i- plcurexanthcnius, . in is.moi'S, McCoy, . I L'hac '!■- liuophthalmus Cheirurus, Chonetcs laticosta, //M rRA, //^ . xxxvii . 204 •201 . -211 (xxxii) IS, 41 44 12 47 42 . 45 42 45 47 . 47 42 45 42 42 47 . 47 . 4! 47 42 .xli, xlii (xlvii) 140, 116, 148, 151 . 150 ll.i . 151 143, 146 xix. 142, 117. 148, 15) 11! xvii, 144 142 Cyphaspis h\bri 01 nata, Hall, ornata, var. baccata, nail, stcphanophora, Hall, C. C. C. i . c. (' c. c. c. Dalmania, l> adspectans. Hall. D. ^Egeria, Hall. . D. anchiops. Hall, D. anchiops, var. armata, Hall. D. bifida. Hall, D. Boothil, Hall, D. calliteles, Emmons, D Calypso, Hall, . D. coronata. Hall, D. Erina, Hall, D. Helena, Hall, D. macrops. Hall. . D myrmecophorus. Hall, D. Pleione, Hall, . D. pleuroptyx, Hall, . D. ielenurus, Hall. HiMiAsnts, Barrande, . (xxix) xs D. acantholeurus. Hall, l> ticanthoplcurus, Conrad. I). .TvgeiiaV.il/ee/janil Worthen, I). iEgeria, Hall, D. JEgeria, Hall, . 1'. anchiops, Green, D. anchiops. Hall, D. anchiops, var. armatus. Hall, D. aspectaus, Conrad, D. aspectans. Hall, 1). bilidus. Hall, . D. Bootlii, Green, D. Boothii, Hall, . D. Boothi, var. Calliteles, Green, D. Calypso, Hall, JJ. Calypto, D. concinnus, Hall, . I). coronata. Hall, D. coronatus, Hall. D. dentata, Barrett, . D. ilenlatus, Barrett, D. denticulatus. Hall. D. imarginutus, Hall, L>. Erina, Hall, D. Erina, Hall, . 1>. Hnusmanni, Brongniart, I). Helena, nail, . D. Helena, Hall, I). limulnrus, Green, 1> mncrops, Hall, D. Meeki, Waleott, D. i»irrurus. Green, I>. myi*mecophoras, Green, D. myrmecophorus, Hall, U. nasutas, Conrad, PAGE. x\ ii, 144. 147 150 . 150 150 . 150 150 ii, 140, 112, 151, 152 .xix, 136, 145, 147 xix, 146, 117 xvii, 143, 143 . xxix, xxx, xxxii 33 . 53 59 K2 53 42 42 61 54 . 67 33 . 68 37 41 2* 49 xxxi, 13,28,63, 113 . 37 40 . 53 x i i , 53 49, 53 18, 28, 29, 32, 52, 63 59 62 xii, 36, 38, 39, 40 33 xii, 53 xii, 45, 47, 182 42, 45 41, 124, 147 xii, 66, 67, 68, 113 64 30 54 .49, 54 58 52, 58 33 xii, 40 xii, 66, 68 67 xxi, 13,29,58, 63 xii, 33, 34, 30 33 . 63 xii, 68 32 28, 29 xii. 34, 36, 33, 39 37 58 INDEX. 233 Dalmanitet. n. sp ?, Hall, D. D. D. D. 1). Ii I). D. D. 1>. l> D. D. D. I> I). D. b. i). i>. D. 1). D. L). D. I>. D. D. D. D. I). D. U D. 1). L). , 32, 52, 58, 52, 56, 52. .">7. xii, 52, 53,54 Ohiocnsis, Meek Ohioensis, Meek, Pleione, Hall, . rlciotie, ll:ill, plearoptyx, Green, |i\ gmsaus, Hall, regalis, i/«*7, . regalis. Hall, rhennnus, Kayeer, sclcnums, Eaton, selenurus, Hall, .... flip iutlet , Meek, .... spiniferus, Bun-mule, tridens, i/aM, .... (Chasmops] anchiops, (Green) 77. pcs-CCI \ :i ( lurke, D pes cervee, Clarke, .... It pes cervat, Etheridge, Woodward ami Jones V. pt's-cervte, Jones and W Iward, li Procne, Clarke, .... D. Procne, Clarke, D. Procne, Etheridgc, Woodward and Jones, D. Procne, Jones and Woodward, In i in roc IRIS, Seoult r. Mi. Ivi, (hii) 171, 187 Belli, Woodward. Ilelli, Etheridge, Woodward and Jones, Belli, Woodward, ', W oodv*, ard and Jon S-ptuni, Etherid Neptuni, Hall, . yeptuui. Hall, Neptuni, Packard, Ocean), Hall, Dolichocephala, . Dolichocephala Lacoana, Claypole, D. Lacoana, Claypole, Dolichopterus, Echiniten, . 187, am, 187, DlPTEROCARIS, Clarke. EOHINOCARIS, Ifhitfieltl E. E. E. in armatu, Etheridge, Woodward and Jones, armata, Jones anil Woodward, armatus, Packard, E. E. E. E. E. E. E E. E. E E. E. E. E. E. E. E. E. E E E. E. S. E. E. E. E. E. E. E. E. E condylepis, Ball, . x\. multinodosa, Beecher, multinodosa, Eiheridge, Woodward & Jonei multinodosa, Whitfield, . multinodosa, Whitfield, mnlli losa, I Whitfield] Hull. multinodosus , Packar punctata, Beecher, . punctata, Hall, \ix, I. liv, 162, 166, 1(S, 170, 174. j>u uctatus, Packard, . punctttttts, Whilllcld, pustulosa, Beecher, ... pustulosa, Etheridgc, Woodward and Jonc* pustulosa, Jones and Woodward, pustulosa, Packard, pustulosa, Whitfield, . liv, 170, 179, pustulosa, Whitfield, pustulosa, I Whitfield) Hall, . socialis, Beecher, liv, 162, 170, socialis. Ueecher, socialis, (lleecher Hall, . socialis. Eiheridge, Woodward and .1 s, subltevis, Etheridge, Woodward and J,(ir/i;/<;i//(i//.\\. iiv,i70, u«, 17s suhlevis, Beecher, sublevis, Packard, sublevis, Whitfield, Whitfield!, Clarke. Wltitfieldi, Clarke, .... Wrightiana, Etheridge, Woodward A. .1 - Wrightiana, Jones and Woodward. PAGE, xx, 200 . 201) no-. 200 .Mi, \\, 202 . 202 •HA . 202 \\, ■-•ill 201 '.'111 . .'HI loo, ins \i\, 194 194 194 191 I''.' 191 191 is? Ii ■.'.'I . 158 1 \ X V i i 16.', 106 166 166 . 166 178, 171 . 180 ISO 170 . ISO \\. 180 I Ml 166 171, 17;; 196, 198 . 166 166 . lis 17s . 17s 17s isn, lsl 178 \\, 178 I7:i, is:. 17) xx, 174 174 176 176 181 176 176 176 172 172 160 160 , 179, •j:; I INDEX. PAGE. PAGE. Eidoihea, .... xlix Lichas Eriopis, iTirii, .... 70, 77, 80, S3 Ei.vmocaris, needier, . . ■ Uv) 181 L. Eriopis, Hall, . . . . 78 |)soJla, //««, . xix, 181. ins I-. furciler, Schmidt, . . .82 A". siliqua, liccchcr, , 182, 185 L. gibbus, Angelin, . . . . .70, 88 K HaK, ... xx 188 L. grandis, Rail, .... xii, 75, 70, 77 E siliqua, Etheridge, W Iwnril and Jones, 182 L grandis, Hall, ..... 73 Entomis, . ... 206 L. grandis, subgenus!, Terataspis, Hall, . 73 Entomolithus, . . . . xxi, xxix I. granulosus, /'. ^4. Bcemer, . 84 Entomostracites, . xxi. xxv, xxix, xxxvi L. Haueri, Barrande, . Si Eqidsetides, Dawson, . . . li, l"i I'M L. hispidns, 77«M, . . . 77 E. Wrightiana, Dawson, Kill L. livheus. Hall, . .76, 83 E. Wrightiana, (Dawson) Wright, 160 L. longispina, Schmidt, ... 82 EsTHKRIA, Rappell, (Ixi) 200, 207. 208 L. I'.iluiata, Barrande, . . . . .70 K. mcnibrnnacen, I'acht, 207 I.. Plautini, Schmidt, .... 82 E palex, Clarice, xix. ;<»; 207 I.. proboscideus, Danles, . . 82 E. pulex, Clarke, ..... 206 I.. I'lv litis, Ihdl, . ... 70, 88 / pulex, 1 thcridge, Woodward and Jones, 206 L. pustulatus, Corda, . . . . 88 E. pulex, I'ackard, ..... .06 L. pustulosus, Ball, . . . 80, 81 Euryptkros, Dekay, . . . (xlix) 156, 158, 2J1 L pustulosus, Hall, . . 80 K approximntus, Bad, . EXPL. plate 37 I.. scaljra, Beyrick, .... 70 1. Ill llCl i. Hull 156 L. Schmidti, Barnes, . . . . .80 /■; chert, Hall, ...... 156 I. simplex, Barrande, ... 88 i promincns, Ball, . . . . - 157 L. superbus, Billings, . . 75,70, 77 / inens. Hall, ..... 157 Z-. superlms, Billings, ... 73 /■;. (Anthraconectes), Meek ami Worthen, 1 1> triconiea, Dames, . . Si) Knvosilcs hemisphericus, ..... •ill I.. tvicuspidnlus, Beyrich, ... 82 . xli, xlii, xlv I.. (Arges) contusus, 77, 1211, 132. 133 p. fecunilus, Barrande, . . .17, 25 1' anguslilVoiid, //«//. xii, xvi, 69,91,92,93,91, 106, 125 I' tntifrons, lironn, .... 23, 24, 25 «. 1>, 120 P. latifrons, Burmeister, .... 113 /' angustifrons, Hall. . . . ,91 P. laLifrons, var occitanicus, Tromelin >nil p. [Cryphaue), . . . . . . , \ \ i l 1'. granulosus, Goldyuss, .... 133 r \Dalmania\, . xxxh P. Halilemani, Mall, xii, xviii, xix, xliv, 97, 113, 116 p [Odontochilc), ..... \\x /'. Haldemani, llall. . . 113 Phai THONIDES, Angelin, (xlv) xlvi, xlvii, 131, 139, 110, 117 P. Maldemani, Walcott, . . • .113 Pli. arenicolus, //all, . . xvi, xvii, xviii 134 P. Ucsione, Mall, . . \ii, 93 Ph. c\ claras, Hall, ..... 137 P l/esione. Hall 93 I'll. - denlicalatus, [Meek\ Hall, . . . xix 139 P. jcjunus, Hall, . xix. l'-'4 Ph gemmsBas, Hall. . . xvii, wiii, xix, 131, 136 P. Isvigatus, Goldfuss, . . .no IMi. varicella, Sail, . xvii, 135, 136, 115, 116 117 P, latimarginatus, /lull. . . . xvi, 1*7 Phaeton, Barrande, . xlv, \i\i, xlvii 14U P Inngiuauilus, Hull, xii, xix, xliv, mi Ph planicauda, Barrande, 110 /' longicawtus, Hall, '31 I'll. striatus, Barrande, .... HO /'. loutjicuudus, II s Williams, . . 1 31 Phill psia, . . xlii, xlviii, 132, 133, lit [16 P. Loveni, Barrande, ■ Ho P crassimaryinata, Billing:,, 99 P. Uacrobius, Hillings. . ■ 139 P. coronata. Hall, . 115 P. macrocophalus, Hall, \ii. xviii, xix, xliv, 97, in. 1 1<> 1'. coronata, Walcott. .... 117 lis. 110. 125, HI. 117. 1'-' /'. coronata ?, N'alcott, . . 115 US /'. macrocephalue, Hull, .... 116 /'. luivis, Hall, . . ... 150 P macroccphalus, var. a . Ball, . . IP' P. Missonriensis, Shumard, 133 /' macrocephuliis, var. a . llall, . 116 p » ornatn, Hull, . .... Ho- P. marginal is, Conrad, xii, 123, 121, 129, 130 P. Shumardi, Herrick, .... rn /'. marginalis. Hall, ... 89 p. Shumardi, Herrick, 133 P marginalise, Hall, . . . ■ 122 236 INDEX. PACK. PACE. Proitus marginal!*, Walcott, . 129 Spathiocaris Emersoni, Clarke, 199 P. microgcmma, Hall, xvii. 109, III S. Em* rsonii, Clarke, 199 L» Missouricnsis, Shumard, , 133 s. Emersonii. Etheridgc, Woodward and Jones, 199 P ifissouriensis, Shuniard, 13:i a. Emersonii, Jones and Woodward, 199 V Mi ouriensis Shumard Hall, 133 s. Emersonii, Packard, . 199 p. is, Barrande, mi Spirifera arenosa, Conrad, 7 p Nevada;, flail. . \i.\, 129, 130 S. arrecla. Hall, . . 18,28, 63 p occidcns, Hall, \ii, xi\. 130 Stre] toiliynclms (Orlhisl liipparionyx, I'anuxem, 18,2s 63 />. pis, Hull, . . 130 Strop liodonta magnifica, Hall, 7 1\ oviirons. Hall, XV i, xlv, 110, 111, 112 STROBILEMS, Clarke, . (lxiiil l.xiv, 212 /' Phocion, Killings, . I -•:. S. spinigera, Clarke, . . xix, Ixiv, 212, 215 p Phocion, [Hillings Hall, xi x, 185 Ml i.uxi in s, I'age, (Ii) 15S, 161, 162,221, 222 /: planimarginatus, Meek, . 1 1 .' s. excelsior, Hall, . . xx, 158, 160, 221, 222 P.? planimarginatus, I Meek) Hall, . xvii, US S. excelsior, Hall, . 158 P. Prouti, Shumard, . 1-25, 1-29, Kin s. Logaui, Woodward, . . Ii, 160, 222 P. t'routi. Shumaril, 12(1 S Powriei, Woodward, . I6D !• Proati, i Shumard Hall, . xix, 126 s. scoticus. Woodward, .... 162 P Kowi, Green, \ii, \i\, xliv, 1)6 12.', '..■:!. 121, 125, 126 S.(?) 1 Enhinocnris ?) Wrightianus, {Dawson) Hall, xx, IGO 23, 129, 130, H7. 182 s. [Slylomurus in error) excelsior, (Hall) Martin 15S p. Kovi i. Green) Hall, . 119 Terataspis, Hall, . (x.xxviii) xl , 73 /'. Iloicii, Hall, 119 TlIVSAXiiI-l.l.Tls. Corria, . . . 13 P. sculptus, Barrandt . . xliv, 132 Trapelocera, ...... (XXV P. -p . Hall, xvi, 94 Trigonaspis, . ' xli P. stcnopygc, xvii, 110 Trilobites, . . xxv ii. xxix. x.xxiv, x.xxvi r 1 nmidns, Hall, xvii, 113 Trilobus, . . . . xxi, xxix p. \ ei neuili, Hall, xii, xvii, 108 Trimerus, . .... xxiii, xxiv p. VerneuUi, Hall, 108 Trinucleus 1, . (XXV r. ( I'liaeton,), xlv Troi nocAiiis, Beecher, . . . (Iv) isi, 197 198 l'ROTOUALANI s. Whitfield, (1x11)200, 210 T. allerntita. Beecher, .... 1S6 P. Hamilton! ii-i-. i Whitfield) Hall, xviii, 200 T aUernnta, {Beecher) Hall, . 186 I'ROTOLIMI l.l s, Paci . (xlviiii 153, 155 T ulternala, Etberidge, Woodward and Jones, 186 p. Eriensis, (fl A' Williams) Hall, 153 T. bicarinata, Beecher, . . . . IS! p. Eriensis, Packard, . 153 T. bicarinata, [Beecher) Hall, . . xx, 18*, IS6 PTERVOOTIiSi 1, lii, 222 T. bicarinata, Etheridge, Woodward and Jones, . 1S4 P anglicus, lr,n T. Haniiltuiiiu', Hall, . .xix, Expi. PL. 30 /' {Leptocheles), lii T interrupta, Beecher, . 1-5 Pi KGOM v. . 211 T. interrupts, {Beecher) Hall, . . xx, 185 ■ i-in oroides, Ball, IS, 63 T. interrupta, Echeridge, Woodward and Jones, . IS-) KHINOCARIS, Clarke, . (Iviii)lx, 195 Turrilepas, Woodward, . (Ixiiii lxiv,21l,215 220 It. columbina, Clarke, . .\ \. 182, 195, 197, HIS T. canccllatus, Hall, .... xvii, 216 i: caphoptcra, Clarke, \i\, 182, 191. 198 T. Devonicus, Clarke, xix, 216, 217 Khyuchouelld cuboides, Sowerby, 13 T. flexuosus, Hall, .... xvii, 215 It. venustula, Hall, 1.) '1'. folialus, Hall, . xix, 218 Si 11 ii ill m, 215 T I?) Newberryi. ( Whitfield) Hall, . . xx, 219 Si KIZODISI i - Clarke, . Uxiii 20/ T. nitiilnlus, Hall, .... xix, 218 S capsa, Clarke, xix, 207 T. squama, Hall, ..... xix, 217 Selenopeltis, XXXV T. lener. Hall, ..... xix, 219 Slimonia, 161 T. Wrightianus, De Koninck, Ixiii, 214, 215 -I'A 1 II ioi iris, Clarke, . il viii) llx, l.xi, 199, 220 T. IPlamnlitos) ..... 215 - Emerson i, Clarke, . xx, 1\, 199 Xiphoaonium. , xli -xliv (geological .Surocn of the Stait of |Uto fiorlt. PALAEONTOLOGY Vol. V, Part II. SUPPLEMENT, CONTAINING DESCRIPTIONS AND ILLUSTRATIONS PTEROPODA, CEPHALOPODA AND ANNELIDA. JAMES HALL, STATE GEOLOGIST AND PALEONTOLOGIST ALBANY, N. V.: CHARLES VAN BENTHUYSEN & SONS. 1888. State of New York, ) Albany, March, 1888. 5 Published under the supervision of the Trustees of the State Museum of Natural History, pursuant to chapter 355 of the Laws of 18S3. PREFATORY NOTE Durinu the progress of Vol. V, part ii, some new material came into the hands of the author, as well as better specimens of some forms already described and illustrated. In order to render available the knowledge thus acquired, a few supplementary plates were lithographed, with the expectation of being permitted to publish them, with the necessary text, within a short time after the appear- ance of the volume at the end of 1879. Unforeseen obstacles in the way of any publication prevented these being made available, and this interruption finally prevented the completion of the Supplement upon the plan originally intended. The material thus prepared was laid aside, and the manuscript notes and observations, made at that time, preparatory for the printing, were mislaid or lost. In 1883, after the passage of the law to limit and complete the Paleontology of New York, provision was made for incorporating these plates, with the necessary descriptive matter, into the work, as a supplementary part of Volume VII, where they now appear. The plates are numbered in consecutive order from cxiv to cxxix inclusive, the last plate of Vol. V, part ii, being cxiii. A single plate is devoted to the more complete representation of the Pteropoda, embracing figures in farther illustration of some species already described, together with others of new forms. During the progress of Vol. V, part ii, the study of the Pteropoda, especially of the genera Tentaculites and Styliola, had suggested the importance of a review of these genera and an inquiry into their relations with Cornulites. It was not until the discussion of the genus Tentaculites had been nearly completed, and the tabular arrangement of species in type, that the author became fully aware of the necessity of this revision and of a farther inquiry 1 PREFATORY NOTE. into the nature of the species described as Tentaculites. On pages 162-165, vol. v, pt. ii, some discussion of this subject has been introduced, and for the purpose of farther elucidation material from various sources was procured for the illustration of the Lower Silurian forms heretofore referred to the genus Tentaculites, and to the more recent genera Conchicolites and Ortonia, pro- posed by Prof. Nicholson ; there being already in hand, from the Waldron col- lections, sufficient material for illustration of the principal phases presented in the development of the Niagara species. The acquisition of new material among the Pteropoda, made it desirable to give some farther illustration of this class, and especially of the Tentaculites, for a better means of comparison with described forms, and also to show their distinction from the elongate annulated forms of Cornulites usually referred to the former genus. I have, therefore, introduced in this connection, and following the illustra- tion of Tentaculites and other Pteropoda, Plates cxv, cxvi, and cxvi a, for the purpose of showing the varying phases of development among certain forms belonging to the genus Cornulites. These plates were introduced primarily, for the purpose of affording means of comparison with authentic forms of Tentaculites since some of the species of the former genus, in their free con- dition, so closely resemble the latter that they have been mistaken for the same and described as Tentaculites. The plates cxvii to cxxix inclusive are given to the Cephalopoda, of which twenty species here described are not illustrated in Vol. V, part ii ; together with a number of others already there described and figured, but which are important as presenting additional features to those already illustrated. All these plates have appeared as photo-lithographs, accompanied by explanations, in tlie Fifth Report of the State Geologist (1886). THE AUTHOR. March, 1888. PTEROPOD A OF T1IK NIAGARA, LOWER AND UPPER HELDERBERG, HAMILTON AND WAVEKLY GROUPS. TENTACULITES, Schlothelm. 1826. (See Vol. v, part ii, pp. 155 I1 The following .species of this genus are illustrated upon the supplementary plate exiv : Tentaculites minutus. PLATE CXIV, FIGS. 1,2. Tentaculites minutus, Hall. Pal. N. Y.. vol. 2. p. is;:, plate a 41, fig-. Sa-e. ls.V_\ Clinton group. Rochester, Monroe county. Tentaculites Niagarensis (Hall), var. Cumberlandle, n. var. PLATE CXIV, FIGS ; 6 This variety differs from T. Niagarensis, Hall (Pal. N. Y., vol. ii, p. 352, pi. lxxxv, figs. 11, 12), in its more conspicuous interstitial annulations and more attenuate form. Niagara group. Cumberland, Maryland. Tentaculites gyracanthus. PLATE CXIV, FIGS. 7-13. Echinus gyracanthus, Eaton. Geological Text-hook. 1882. Tmiaculites irregularis, Hall. Pal. N. Y., vol. 3, p. 137, pi. vi, figs. 22. 28. 1859. Tentaculites gyracanthus, Eaton (Hall). Pal. N. Y., vol. 8. Expl. pi. vi. The Tentaculites regtilaris and T. irregularis of Castelnau (Essai sur le Syst. Sil. de l'Amer. Septentrionale, 1843), described as from the Trenton limestone, are probably from the Lower Helderberg group, and identical with this species. (See Pal. N. Y., vol. v, pt. ii, p. 156, foot-note.) 6 PALEONTOLOGY OF NEW YORK. Lower Helderberg group (Tentaculite limestone). Clarksville, Albany county; Schoharie, Schoharie county, and Jerusalem Hill, Herkimer county. Tentaculites elongatus. PLATE CXIV, FIG. 14. igatus, Hall. Pal N. Y., vol. 3, p. 136, pi. vi, figs. 16-21. 1859. Lower Helderberg group. Schoharie, Schoharie county. Tentaculites acula, n. sp. PLATE CXIV, FIGS. 15-17. Tins species is distinguished by the regular, equidistant annuli and the few ambulations on the intervals. Lower Helderberg group. Port Jervis, Orange county. Tentaculites Dexitiiea, n. sp. PLATE CXIV, FIG^ 18, 19. Tentaculites scalariformis (parthn). Hall. Pal. N. V., vol. v, pt. ii, p HIT. is7:>. This species is distinguished from the T. scalariformis occurring in the Upper Helderberg limestone by its more elongate and slender form, and more sloping annuli. Schoharie grit, Pendleton, Indiana. Tentaculites scalariformis. PLATE (XIV, FIG. 20. Tentaculites scalarifonais, Hall. Pal. N. V.. vol. v, pt. ii, p. 167, pi. xxxi, tigs. 3-11. 1S79. Corniferous Limestone. Delaware, Ohio. HYOLITHES, Eichwald, 1840. (See Vol. v. part ii, pp. 191-202.) Hyolithes centennialis. PLATE CXIV, FIGS. 21-23. Hyolithes centennialis, Hakrbtt. Ann. Lyceum Nat. Hist., vol. xi, p. 299. 1877. Lower Helderberg group. Port Jervis, Orange county. PTEROPODA. 7 Hyolithes herds, n. sp. PLATE CXIV, FIGS. '21 27. This species is characterized by its large size, broadly crenulated lateral mar- gins, and its finely and closely striated dorsal or convex surface. Lower Helderberg group. Near Clarksville, Albany county. STYLIOLA, Lesueuk. 1826. (See Vol. v. part ii. pp. 175-182.) Styliola spica, n. sp. PLATE CXIV, FIG. 28. This species differs from S. fissurella, Hall, of the Hamilton and Portage groups, in its much greater size, more robust form, and in the absence of any indications of annulations or apical node. Hamilton group. Hamburgh, Erie county. COLEOLUS, Hall. 1879. (See Vol. v, part ii, pp. 184-190.) COLEOLUS HERZERI, 11. Sp. PLATE CXIV, FIG. 2!). The shell of this species is of unusually large size, slightly incurved toward the apex, and the surface is marked by low, faint, obsolescent and somewhat irregular striations. Waverly group. Medina county, Ohio. PHARETRELLA, nov. gen. Shell large, elongate, Hyolithes-like in outline ; apex acute, transverse section probably triangular ; substance tenuous ; ornamentation consisting of trans- verse, imbricating undulating striae. Pharetrella tenebrosa, n. sp. PLATE CXI V,-.FIGS.!30,'.31 . Genesee slate. Genesee county. TUBICOLAR ANNELIDA. CORNULITES, Schlotheim. 1820. For the discussion of the nature and biological relations of forms referred to tins genus, see the following authors: 1820. Schlotheim, Cornulites serpularius. Petrefactenkunde, p. 378, pi. xxix, fig. 7. 1834. Kloeden, Axis of Trilobites. Verstein. der Mark Brandenb. 1839. J Sowerbv, Cornulites (incertce sedis). Murchison's Silurian System. 1845. De Verneuil anil Kevserling, Columns of Cystideans. Russie et Oural. 1847. Hall, Tentaculites ? Pal. N. Y., vol. i. ' 1848. Conrad, Cornulites (incerta sedis). Jour. Acad. Nat. Sci. 1851. McCoy, Cornulites (incertce sedis). ("Probably Echinodermata or Annu- lata.") British Pal. Fossils, p. 63. L852. Hall, Cornulites (incerttz sedis). Pal. N. Y., vol. ii. 1853. Keyserling, Corals. Bull, de la Soc. Geol. 1856. Shumard, Tentaculites. Geol. Report of Missouri. 1859. Salter, refers Tentaculites and Cornulites to the Annelida. Siluria, 3d Edition, pp. 221 and 229* 1864. Ludwig, Pteropods. PalEeontographiea. 1865. Meek and Worthen, Tentaculites. Proc. Acad. Nat. Sci. Phil. 1867. Barrande, Cornulites (Annelida). Syst. Sil. de la Boheme. * Under the head of Aunelides of the Older Silurian Strata, Mi-. Salter uses the following- language in id of Siluria, page 221, Third Edition. 1859: "The Tentaculites and Cornulites ••( il arly primeval strata must also be mentioned as remains of animals of this order. Thej were worms with shelly tubes like those of Serpula, but distinguished easily by their annulated form and cellular structure. f' ' The e tos ils, Tentaculites ami Cornulites, have been assigned to various groups of animals, the notion Fcrinoidal creatures being the most g rally accepted. They were, however, shelly » > i > .- - ~ . of a highly complex cellular structure, not jointed tentacles or stems; and could, by no means, be parts of guch animals.— J. w. s." TUBICOLAR ANNELIDA. 9 1868. Meek and Worthen, Tentaculites. Geol. Survey of Illinois. Geol. and Pal., vol. iii. 1872. Nicholson, On the genera Cornulites and Tentaculites, and on a new genus Conchicolites. Am. Jour. Sci., Third Scries, vol. iii, p. 202. 1872. Nicholson, On Ortonia, a new genus of Tubicolar Annelides, with Notes on the genus Tentaculites. Geol. Mag., vol. ix, p. 446. 1873. Nicholson, Description of two new species of Annelides, Conchicolites and Ortonia. Geol. Mag., vol. x, p. 54, pi. iv. 1874. Nicholson, Ortonia intermedia. Geol. Mag., New Series, vol. i. 1874. S. A. Miller, Tentaculites. Cin. Quart Jour. Sci. 1878. S. A. Miller and C. B. Dyer, Spirorbis. Jour. Cin. Soc. Nat. Hist. 1879. Hall, Spirorbis [?]. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist. 1879. Hall, Cornulites (Annelides). Twenty-eighth Rept, N. Y. State Mus. Nat. Hist. 1884. Ringueberg, Cornulites. Proc. Acad. Nat. Sci. Phila. In the study and description of the species illustrated in the Paleontology of New York, Vol. V, pt. ii, under the generic names of Tentaculites, Styliola, Coleoprion, Coleolus, Hyolithes, etc., there appeared little difficulty in recog- nizing their relations to each other and their nearest affinities as with the Pteropoda. The only question arose in considering certain species, which had originally been referred to the genus Tentaculites, and of which, in the begin- ning, I had no knowledge from the actual examination of specimens. In the tabular arrangement of the American species of this genus (p. 162, loc. cit.) I admitted into the list five forms which had been described as Tentaculites, from the Hudson River horizon (Cincinnati group). Even before the pages had gone to press I began to doubt the generic identity of these forms with true Ten- taculites, and an examination of the species from the neighborhood of Cincinnati, brought confirmatory evidence of my suspicion as to their true affinities. At a later date, through the kindness of Mr. S. A. Miller and the late Mr. C. B. Dyer, I was enabled to study a collection of specimens which seemed to present a pretty complete life-history of those forms described as Tentaculites from the Cincin- nati region. 10 PALAEONTOLOGY OF NEW YORK. The forms des&ribed us T. tenuistriatus, T. Oswegoensis, T. Sterlingensis,* and T. Rirhmondtnsis;\ are rarely if ever quite straight, and are usually considerably curved, a feature unknown among the most characteristic forms of the genus I i i.itks. The T. incurvus of Shumard, now recognized as from the same horizon, is a curved form, as the name implies. We have at the outset, there- fore, in all these species, to recognize a deviation from the acknowledged char- acteristics of Tentaculites as described by the best authors and as known to us in American and European rocks. These forms in their intermediate stages are sharply annulated, and, in their advanced stage of growth, always longitu- dinally striated in a manner not observed among true Tentaculites. Farther observation shows that in their young state they are parasitic, often occurring in groups, with their bases in contact and attached to some foreign body, as a shell or a fragment of a crinoid column ; and that the extreme basal portion or initial point, in the young state, is always curved, often to a full volution; but this portion becomes absorbed, dissolved or worn off as the animal increases in size and the tube assumes a more or less direct manner of growth, continuing in a straight or slightly flexuous line and gradually enlarging toward the aperture. These tubes which in their beginning are apparently smooth, gradually become annulated and finally striated longitudinally. It usually and perhaps always happens, however, that during some stage of their growth, not always depend- ing on the age, the walls become thickened and the annulations obsolescent. < >ccurring either singly or in groups, wherever the surface of attachment is broad enough to admit of it, they continue adherent until they have attained a con- siderable size — that is, a length of 20 to 35 mm., or even more. The apertures in nearly all examples are apparently incomplete, or with the margins broken. The phases here described are illustrated in figures 1-11 of plate cxv. I nder other circumstances, where apparently the conditions have been un- usually favorable, these colonies, adherent to some other body at their bases only, continue to increase in length and diameter; the lateral walls from being simply in contacl become coalescent, and they continue this growth till the form s of the Academy of Sciences, Philadelphia, and Report Geological Survey of Illinois. vol. iii. \. Miller, Cin. Quart. Jour. Sci. 1874. TUB1C0LAR AXMILIDA. II of the tubes and of the apertures become angular, and they present the aspect of a colony of Favosites. In other well-preserved groups, the cells, in a greater or less degree, retain their individuality, presenting a tubular appearance and circular or sub-circular apertures. These conditions are illustrated in figures 18-23. As a general feature these tubes (in the Lower Silurian forms), whether singly or in larger or smaller groups, usually become more distinctly and extreme! , annulated as they recede from the initial point, while the longitudinal stria' become more distinct. It sometimes happens, however, that at an earlier stage of growth (figs. 12-14 of plate cxv). but often at a later period, the walls become thickened and the annulations are not developed, or they become obso- lescent or even quite obsolete from this thickening of the tissue. In this con- dition they present an undulating surface with obscure or indistinct annulations. as in figure 27, plate cxv, which may be partially due to erosion. The condi- tion of surface shown in figures 12-14 is seen in its more extreme degree in figure 15; a longitudinal section of which is shown in figure 16, plate cxv. We observe in this example the unequal development of the intermural cellular tissue which begins at a much earlier stage in some individuals than in others. When these tubular bodies, in their advanced growth, are cut transversely or longitudinally the wall is usually found to consist not of a single lamina, or of cohering parallel laminae, but being more or less of a vesicular tissue, which in some examples is scarcely, or even not at all developed, while in the majority of individuals this texture is a conspicuous feature. This tissue is rarely, if ever, observed in the extremely young state. It usually, but not always, in- creases with age, and upon its development depends the thickening of the walls. In some specimens, of apparently adult growth, the vesicular structure is not developed, and the inner and outer walls are in contact or separated from each other by simple uninterrupted space. The varying degrees of development in this intermural tissue are shown in the longitudinal sections, figures 32-39 of plate cxv; some of which are from single and separate individuals, and others from groups, like those represented in figures 7-13. Figures 15 and 16 illustrate 12 PALEONTOLOGY OF NEW YORK. a specimen with abnormally thickened walls and great development of vesicu- lar tissue. With all the material here illustrated on plate cxv, and much more before me, I am unable to find any characters by which generic or specific distinction can be drawn between the forms represented in figures 1 and 2 and all those which follow up to figure 39. The names under which these and similar forms, as before mentioned, have been described are: Spirorbis Cincinnatensis, Tmlacu- lites incurvus, T. tenuistriatus, T. Oswegoensis, T. Sterhngensis and T. Richmondensis. Besides the species above enumerated, these organisms, in their different phases of development, have furnished the basis for the establishment of the genus Ortonia (O. minor and 0. corded), and a species described under Conchico- i.rrr.s ((' corrugatus). The latter genus was founded upon a similar organism, occurring in the Caradoc shales of Westmoreland, England, the equivalent, in age, of the Hudson River group of America (American Journal of Science, Third Series, vol. iii, p. 202. 1872). The manner of growth and development; the external form and internal structure of these bodies, seem to demonstrate very clearly that they should be all referred to the genus Cornulites, as described and illustrated by the author of the genus and by subsequent authors whose opinions are entitled to respect. The description and illustrations of Cornulites serpularius, Murchison (Silurian System, p. 627, and plate xxvi, figures 5-9), present a most important study in this connection, ami leave no doubt as to the nature of the organism under consideration. In regard to the forms illustrated on plate cxv, figures 1-39, I do not propose to recognize any distinction of species, and I leave them without prejudice to be referred to such specific names as their authors may claim for the various phases here represented. Though referring certain of the illustrations to the names by which they are usually recognized, I have purposely confined myself to the discussion of the various phases of what appears to me a single form of this re- markable organism, all the specimens being from the same geological horizon. Figure 10 represents the earlier stages of an irregular group growing upon the shell of an Orthoceras, from the (Jtica slate of New York, and which pre- TUBICOLAR ANNELIDA. 13 sents all the phases of development from the convolute, spirorbiform condition to the nearly straight forms, and all have a very similar aspect to the speci- men represented in figures 1 and "J of the same plate. We know it only in it- immature condition, in the single specimen illustrated. In figure 41 the tubes are somewhat more slender and more flexuous than in specimens of the same degree of development from the region around Cincin- nati, and this form will probably prove a, distinct species. The figure is from the original specimen, described as Tentaculites? flexuosus, from the Trenton lime- stone (Pal. N. Y., vol i, p. 92, pi. xxix. figs. 6a-d). Want of material will prevent a complete comparison and final discussion of the relations of this species with any other, at the present time. The forms illustrated on plate lxxii, figs. 2 a and b, Pal. N. Y., vol. i, p. 284, were referred to the species Tentaculites [/J flexuosa, the ? after the generic name being accidentally omitted. A comparison was also suggested with Cor- nulites serpularius, Schlotheim (Murchisoifs Sil. Syst., p. 627, pi. xxvi, figs. o-8). The specimens from the Hudson River group of New York are, however, more slender and are frequently regularly curved, not flexuous as in the typical form of T. ? flexuosus, from the Trenton limestone. They are very similar to, and perhaps identical with those from the same horizon in the west, and their probable identity with the western forms was at that time recognized in citing the localities. W e come now to consider some forms of this genus known to us in the higher rocks, and more especially the single species occurring in the Niagara group at Waldron, Indiana. The material at hand is not so complete in some respects as that from the Hudson River group of the Cincinnati region, repre- sented on plate cxv. In its entire aspect, however, it presents the same phases of development, and we have more complete material to illustrate the advanced stages of growth in this species. The earliest condition in which their specific relations usually are observed, is that of groups of slender, flexuous, or rarely almost straight tubes, attached on one side for nearly or quite their entire length to some other organisms, as the shell of a Brachiopod, a Gastropod, or the calyx of a Crinoid. In this condition the apertures are frequently turned outward. 14 PALEONTOLOGY OF NEW YORK. Their bases are almost always more or less curved, sometimes making nearly an entire volution before diverging to the flexuous or straight line. On carefully examining the surfaces of shells where these parasitic tubes oc- cur, there are often found numerous circular specs attached to the shell-surface. Many of these, under the naked eye, or an ordinary magnifier, appear as simple circular disc- of calcareous matter, while under a higher power a minute con- volute tube is distinctly visible. These in their larger growth become spiror- biform, and are apparently identical with those described as Spirorbis inornatus, Hall (Twenty-eighth Annual Report of the State Museum of Natural History, page L81, pi. xxxi, figs. 14, 15). The material in our possession is not sufficient to demonstrate a gradual and absolute transition from these minute convolute discs, through all the phases of development, to the recognized Cornulites ; but I believe they are identical, and that by careful examination of larger collections all intermediate stages of growth and development may be found. The ordinary condition of the young of this species is that represented in figures 1-4, plate cxvi, where the tubes grow singly or in groups, with one side attached and the free portion sharply annulated. In this condition the aper- tures present an irregular margin, as if the continuation of the tube had been broken away, and much the greater proportion of the specimens are found in similar condition. In specimens represented in figures 5 and 6, the acute apex is preserved in its incurved condition. In figure 5 the annulations are less distinct than usual on the earlier portions of the tube, while in figure 6 this feature is strongly marked in the lower part of the specimen, becoming obso- lete above, or merged into the thickening tissue as growth progresses. In figure 7 the apex is slightly incurved, the annulations distinct below, but becoming obsolete above. In figure 8 we have two individuals attached by their bases to the surface of Platyostoma Niagarense. The apical portion is less distinctly annulated than in some other specimens, and the original initial point has probably been dissolved or eroded. In the progress of growth the regular annulations soon become obsolete in the thickened tissue above, which is finely striated longitudinally, and presents an irregular lamellose surface. In figure 9 TUBICOLAR ANNELIDA. 15 the apex is much thickened, the initial point having been removed or absorbed; the annulations are obsolete and the surface lamellose. The specimen is attached for the greater part of its length to the calyx of an Eucalyptocrinus crassus. Figure In represents the largest specimen observed. The apex and the surface of adherence have been broken off, and only the free portion re- mains. This preserves the concentric lamellose-annulate character, and finely striated surface. Figures 11 and 12 are interesting as showing an irregular lamellose growth, and the fracturing of the test, which has been subsequently healed duringthelife of the animal. In many instances, where the test has been broken and again restored, the continuity of the strife is interrupted, as illustrated in the specimen, fig. 13. As the individuals advance in growth, the inner and outer walls of the tube become separated, and the intermural space filled with vesicular tissue. This separation of the walls and the development of the tissue is not always in proportion to the size of the individual, nor is it uniform on all parts of the circumference of the tube in the same specimen. It is rare that individual tubes, cut longitudinally through the center, show an equal development of this tissue on the two sides. In figure 14, a section of a small individual, the tissue on one side encroaches largely upon the visceral cavity, while on the other it is only incipiently developed. Figure 15 shows an unequal development of the tissue on the two sides; and figure 1G, a section of one of the largest individuals known, shows but an incipient development of this tissue. In figure 17 this vesicular structure is subequal on the two sides, while fig- ure 18, a farther enlargement, shows the vesicles developed within the inner walls and encroaching upon the visceral cavity. This irregularity is especially shown in the transverse section, figure 19, where upon two sides there is no development of tissue, the walls being apparently quite solid as represented. In figure 20, however, we have a more distinct manifestation of this unequal de- velopment, where the upper or barren side, as shown in the figure, has probably been the attached surface. While there is a general similarity in this vesicular texture, there is no uniformity in size or form of the vesicles, as may be seen in any one of the sections, and especially in figures 18 and 21 of plate cxvi. 1., PALEONTOLOGY OF NEW YORK. To Summarize the Characters: These organisms, in their earliest recognizable conditions of existence, appear :is a simple point or spec upon the surface of some other organism, becoming a slender enrolled tube where the volutions (so far as can be determined) may be in the same plane and having the form of Spirorbis, under which designation they have sometimes been described. In its farther development the body becomes an elongate, straight or sinuous tube. In the earlier stages these orgaisms, either singly or in groups, remain attached to the surface of some or- ganic or inorganic body, and the continuation of this parasitic condition depends upon the size of the body or extent of surface upon which they may continue to mow. Beyond the limits or extent of the surface affording means of attachment, they heroine free and continue their growth in a constantly expanding tubular form. In their earlier stages the substance of the fossil consists of an inner and an outer wall, which are in contact; the exterior becoming annulated at an early period, and the inter-annular spaces, or the upper inner margin of these annular growths, produce sharp interior annulations, which often extend considerably within the visceral cavity, so that when the exterior becomes worn away, or the fossil is cut through on one side of the center, they often give the aspect of a septate tube. In the first recognized stages of this organism, the tube is apparently smooth, hut in the later conditions the annulations are conspicuous and again become gradually obsolete with the growth of the animal. The longitudinal striae, which are at first obscure, become developed with the growth of the tube, and continue a conspicuous feature after the obsolescence of the annulations. The intermural vesicular tissue becomes developed only with the expansion of the tubular growth, and especially after the organism has assumed a free condition of growth. In their earliest known condition these bodies are always parasitic, and they are not known to begin their existence as a free organism. Whenever, in their advanced state of growth, they occur in a free condition, it will be found that the initial point is wanting, having been broken off and the marks of the frac- ture still remaining, or the surface has become cicatrised. TUBICOLAR ANNELIDA. 17 The following forms are here regarded as representing various stages of development of what appears to be a single species of the genus CORNULITES. The figures to which names are here applied are those most nearly resembling the illustrations of the several species as given by the authors, and not as determined by the writer. SP1R0RBIS, Lamarck. IS01. Spirorhis Cincinnatensis. PLATE CXV, FIGS. 1,2. tSpirorbis Cincinnatensis, Miller and Dyer. Jour. ('in. Soc. Nat. Hist., vol. i, p. 38, pi. i, fig. 13. l*7s. Hudson River group. Cincinnati, Ohio. ORTONIA, Nicholson. is7l». Ortonia ?ninor. PLATE CXV, FIG 3; AND PLATE ex VI a FIGS. 19,20. Ortonia minor, Nicholson. Geological Magazine, vol. \. p. 56, pi. iv, fig. 2a. 1ST:;. Hudson River group. Cincinnati, Ohio. Ortonia conica. PLATE CXV, FIG. J7 ; AND PLATE CXV1 v. FIGS. 15, 16. Ortonia conica, Nicholson. Geological Magazine, vol. ix. p. 447, fig. 1. 1S7'J. Hudson River group. Cincinnati, Ohio. CONCHICOLITES, Nicholson. 1872. Conchicolites corrugatus. PLATE CXV, FIG. 27 ; and PLATE CXVI a, FIGS. 17, 18. Conchicolites corrugatus, Nicholson. Geological Magazine, vol. x, p. OS, pi. iv. lif,'. :i. I S73. Hudson River group. Cincinnati, Ohio. T E NT ACULITES, Schlothkim. Isl'o. Tentaculites Sterlingensis. PLATE CXV, FIGS. 5-7, 32. Tentaculites Sterlingenns, Meek and Worthkn. Proe. A.cad. Nat. Sci., p. 255. 1865. Hudson River group. Cincinnati, Ohio. 18 PALEONTOLOGY OF NEW YORK. Tentaculites Richmondensis . PLATE CXV, FIGS. 28-30,33-39. Tentaculites Richmondensis, Miller. Cin. Quart. Jour. Sci. 1874. Compare '/'. teiittistriatus, Meek and Worthen. Proc. Acad. Nat. Sci., p. '2'A. L865. Hudson River group. Richmond, Indiana. CORNULITES, Schlotheim. 1S20. CORNULITES FLEXUOSUS. PLATE CXV, FIGS. 41,42. Tt ntaeiUites? flexiwsa. Hall. Pal. N.Y., vol. i, p. 92, pi. xxix. figs. 6a-d ; p. :2S4, pi. lxxviii. figs. 2a, b. 1847. Not C sits, Hall. Pal. N. Y., vol. ii. p. 98, pi. xxviii. fig. 12. :»x. Hu.l. Twenty-eighth Rept N Y. State Mus. Nat. Hist., p. 184. 1879. Trenton limestone. Lowville, Lewis county. CORNULITES IMMATURUS. PLATE CXV, FIG. 4(1. This species is known only in an early serpuloid stage of growth, and may eventually prove identical with the forms occurring in the Cincinnati group. Utiea slate. Holland Patent, Oneida county. CORNULITES INCDRVUS. PLATE CXV, FIG. 31 ; and PLATE CXVI, FIG. 31. Tentueidites incurvns, Shdmard. Geol. Rept. Missouri, part ii. p. 195, pi. B. flgs. 6a, 6b. 1856. In the ultimate revision of these forms, the specific name "incurvus" will take precedence over all others in point of time. Hudson River group. Cape Girardeau, Missouri. CORNULITES DISTANS. PLATE CXVI, FIG 23. Tentamdites distans, Hall. Pal. N. Y., vol. ii. p. 184, pi. a xli, fig. 9. 1852. Clinton group. Rochester, Monroe county. CORNULITES ClINTONI. PLATE CXVI, FIG. 22. ' voliU fit ruosus, Hall. (Name prec upied.) Pal. N. Y., vol. ii. p. 98, pi. xxviii. tigs. 12a-e. ' ' ' ' '.intoni, II ml. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist,, p. 184. 1879. : ' iidite. arcuatus, Conrad. Jour. Acad. Nat. Sci., vol. viii, p. 276, pi. xvii, fig. 8. 1848. This species was originally described under the name Cornulites flexuosus {loc. cit.% bul as the Tentaculites ? flexuosus of Hall, which had been previously de- TUBICOLAR ANNELIDA. 19 scribed, was subsequently proved to be a Cornulites, the name of the former species was changed by its author to Clinton/. The Cornulites arcuatui of Conrad, from the Niagara limestone, in Orleans county, hears a close resemblance to speci- mens of C. Clintoni, and the type may represent a small individual which re- tains the substance of the tube. Mr. Conrad's specimen is not accessible, but in the event of the identity of the species being proved, the specific term arcuatus will take precedence. Cornulites, sp. ? PLATE CXVI, FIGS. 24, 25 This specimen has the distant, regular annuli of C. distans, but the evidence of vertical striation is very obscure and unsatisfactory. The specimen is in a crystalline condition, and on this account the small portion of the test remain- ing preserves only obscure indications of its original condition. When examined by transmitted light, there is evidence of a distinct transverse line upon the ambulations, above which the ring is darker, and below more translucent, appar- ently indicating the line of articulation of the joints of the tube. The apparent transverse strife on the figure are due to the texture of the surface, and are not organic markings. Clinton group. Near Lockport, Niagara county. Cornulites arcuatus. PLATE CXVI A, FIG. 9. nulites arcuatus, ConkAd. Jour. Acad. Nat. Sri., vol, viii, p. 27'j. pi. xvii. fig. 8. 1842. Niagara group. Albion, Orleans county. Cornulites proprius. PLATE CXVI, FIGS. 1-21 proprius, Hall. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist., p. 182, pi. xxxi.figs. 1-13. 1ST:'. The species referred to Cornulites - (==C. bcllastriata) (Pal. N. Y., vol. ii, he. cit.), is allied to C. proprius in its surface characters, although manifesting a tendency to greater regularity in the annuli, and having finer and less prominent longitudinal striatums. It may, however, properly be regarded as the New York representative of the Waldron species. The species C. contractus. Ringueberg (Proc. Acad. Nat. Sci., p. 148, pi. iii, figs. G, 6a, 6b, 1884), from the Niagara group 20 PALEONTOLOGY OF NEW YORK. at Lockport, is suggestive of the same stage of development as that represented by figures 1 -4 of C. proprius, and it may prove to have a similar relation to the larger individuals from this horizon in the State of New York. C. nodosus, Ringueberg (loc. cit.), p. 149, plate iii, fig. 7, is a very small form from the same formation, the surface of which is without annuli, but is covered with faint tubercles. Niagara group. Waldron, Indiana. COKNULITES BELLASTKIATUS. PLATE CXVI a, FIGS. 12 anil 13. Carnulites , Hall. Pat. N. V., vol. ii. p. 353, pi. lxxxv, figs. 112-17. 1S52. Tin; earliest conditions of this species have not been observed. In the most nearly entire individual known, the base is slender and somewhat rapidly attenuate. The annulations become subdued or obsolescent at a comparatively early period of growth, and in old specimens are often entirely obsolete. Fine longitudinal striae are early developed and continue. CORNDLITES CHRYSALIS, H. sp. PLATE CXVI, FIGS. 26-28 This species is characterized by its regular and closely set annulations, which present the appearance of inverted, ensheathed, truncated cones. Lower Helderberg group. Near Clarksville, Albany county. CORNULITES CINGULATUS, 11. Sp. PLATE CXVI, FIG 29 Tube very llexuous, with regularly transverse but unequally distant, sharply angled or evenly rounded annulations. Lower Helderberg group. Locality doubtful. CORNULITES TRIBULIS, 11. Sp. PLATE CXVI, PIG. :'." Tobe characterized by its gently sinuous outline, low, irregular annulations, and line but conspicuous longitudinal striae. Hamilton group. Hopewell, Ontario county. A DDEN DA. (See Plate CXVIa.) The following description and illustrations of Cornulites are from Murchi- son's " Silurian System," published in 1839. Under the head of "Fossil Shells of the Wenlock Limestone," J. De C. Sowerby describes Cornulites serpularius, as follows : " Cornulites serpularius, Schlot., pi. xxvi, f. 5 (Schloth. Petr., t. xxix, f. 7). We can scarcely attempt a description of this anomalous fossil, of which at present but one species is known. So unlike is it to anything we have seen, that we are unable to assign it a place in the system of animals, or draw a comparison between it and any other creature. Its general form is a much elongated, hollow, more or less crooked cone, open at the base; in its early -tat.' it is parasitical, being attached by its side and often in pairs. The exter- nal crust is longitudinally striated, and marked with slightly raised rings, which indicate its passage over the margins of the series of truncated cones of which the fabric is constructed. These short cones are placed within each other, their widest edges being directed toward the apex of the general envelope, the small- est or most internal cone occupying the apex itself. Thus they form a pyramid of cups, or if viewed in a reverse position, a series of broad rings gradually increasing in size, and capping but not covering each other. Each cup or ring is thinnest at that part which is inclosed by the succeeding ring, where also its diameter is least; both surfaces are of a foliated structure, and the outer blends with and is lost in the external coat. Internally, each ring was apparently of a cellular structure, for it is composed of depressed, imbricating, and regularly arranged grains of calcareous spar. Some of the grains leave an impression upon the surface of each of the steps, which is formed upon the cast of the cavity of the cone by the thick edges of the rings. "If the cells were the habitations of minute Polypes, they must have opened upon the edge of the cup, and each succeeding generation must have been located around the parent stock, and not upon or within the Polyparium, as in corals; but there is no appearance of stellas or radiating laminae. Upon the cast of the inner cavity may often be observed two, three, or more longitudinal impressions, each composed of two nearly approximating, fine, sunken lines, produced by elevations where probably there were joinings in the cups. The 22 PALEONTOLOGY OF NEW YORK. cone of the larger specimens is generally rather straight, with the rings regular, and no appearance of having been attached to any other body; but the young specimens arc irregularly curved, have; more or less distorted rings, and are lixed upon corals or shells. With such only does Schlotheim appear to have been acquainted, and had not we been supplied with a complete series by Mr. 1>. Bright, we should have been induced to consider the full-grown specimen as another species of the same curious genus."* " Locality. Western slopes of the Malvern Hills ; Dudley." In 1S72 Prof. Nicholson (Am. Jour. Sci., he. cit.) proposed the name Conchi- colites, in the following terms: " Conchicolites, Nich. — Animal social, inhabiting a calcareous (?) tube, attached in clustered masses to some solid body. The tube conical, slightly curved, attached by its smaller extremity. The wall of the tube thin, its ex- ternal surface devoid of longitudinal striae. The tube thin, composed of short imbricated rings, but apparently destitute of any cellular structure. Cast of the tube composed of short conical rings, its surface completely smooth, and destitute of striae or furrows. " Conchicolites gregarius, Nich. — Tubes closely in contact, attached by their -mailer ends to dead shells. Tubes varying in length from a quarter to half an inch, and having a diameter at its mouth of about half a line." " The preceding species is found growing upon the shells of Orthocerata in the Lower Silurian of the North of England. " The following described species are from the Lower Silurian in the neighbor- hood of Cincinnati." In the Geological Magazine, vol. ix, 1872, Prof. Nicholson published a paper on " Ortonia, a New Genus of Fossil Tubicolar Annelides." " The following diagnosis gives the characters of the genus Ortonia, and of the single known species: "Ortonia, Nich. — Animal solitary inhabiting a calcareous tube, which is attached along the whole of one side to some foreign body. Tube slightly * In the discussion of these forms in the Third Edition of Siluria, under the Wenlock series, page 259, Mr. Salter gives the following interesting facts: " Cornulites serpularius (see pi. xvi, f. 3-10) is still, .-is in the Llandovery rocks, the principal annelide j and, tl gh more frequent in the Wenlock limestone, is net rare in the Ludlow rocks. The finest specimens from the Wenlock limestone of Ledbury; but at Dudley Cornulites are found attached to shells, in groups of thi r four together, like Serpulse, and they occur in profusion on the hard and seaworn surfaces nf Ludlow rock at Marloes Bay, in Pembrokeshire, in masses a foot in diameter." ADDENDA. 23 flexuous, conical, in section cylindrical, or somewhat flattened laterally, and sub- triangular. Walls of the tube thick, cellular along the surface opposite to the attached portion, markedly annulated along the sides. " Ortonia conica, Nich. — Tubes growing attached to the shell of some Mollusc; varying in length from a quarter to half an inch, with a diameter of about one- tenth of an inch at the mouth. Lateral annulations of the tube varying in number from thirty to thirty-five in the space of an inch. Surface smooth and completely destitute, so far as observed, of longitudinal striae. " The fossil from which the above description has been taken is an example of Strophomena alternata, to the dorsal valve of which are attached the remains of more than twenty individuals of Ortonia conica. In one case the tube of one crosses that of another individual ; but it is quite clear that this is an accidental circumstance, so to speak, and that the tubes are truly solitary. The specimen is from the ' Cincinnati group ' of South-western Ohio, a formation which be- longs to the ' Hudson River series,' and which corresponds with the Caradoc or Bala division of the Lower Silurian. " In conclusion, I may add that Mr. Orton has submitted to me a beautiful specimen, apparently of the Tentaculites tenuistriata of Messrs. Meek and Wor- then, and also from the Cincinnati group of South-western Ohio. If this specimen be rightly determined, I cannot avoid the conclusion that it is truly referable to the genus Cornulites of Schlotheim, differing from the familiar Cor- nulites serpularius in its small size, and in some other minor characters. This conclusion, however, does not admit of complete verification except by the dis- covery of specimens absolutely attached to some foreign body." In the Geological Magazine, vol. x, 1873, the same author publishes "Descrip- tions of Two New Species of Fossil Tubicolar Annelides." He redescribes the genus Conchicolites and the species C. gregarius, and describes the follow- ing new species — Conchicolites corrugatus, Nich., and Ortonia minor — in the following terms : " Conchicolites corrugatus, Nich. — Tubes growing socially in clustered masses upon the shells of molluscs; calcareous; destitute of vesicular structure ; coni- cal, and gently curved. Attached by their smaller extremities, sometimes for the space of a line or more ; and either partially free, or contiguous to one another throughout the remainder of their course. Length of the fully-grown tube one-half inch or a little more; diameter of tube at mouth one- tenth of 24 PALEONTOLOGY OF NEW YORK. an inch. Tube composed of conical imbricating rings, about forty in the space of one inch (about four in the space of one-tenth of an inch), giving the tube a strongly annulated appearance. "The specimen figured exhibits the tubes of more than thirty individuals of chicolites corrugatus, attached to the spire of Cyclonema bilix, Conrad. ■■ From Conchicolites gregarius, the present species is distinguished by its greater average length and much greater diameter, by its much less closely crowded habit, and 1>\ its much more strongly marked annulations. ■• Locality and formation. Attached to the shell of Cyclonema (Plcurotomaria) bilix, Conrad, from the Hudson River group (Lower Silurian), of Cincinnati, Ohio. " Ortonia minor, Nich. — Spec. Char. Tube calcareous, solitary attached by the whole of one side to some foreign object. Length of tube from one-tenth to three-twentieths of an inch; diameter at mouth from one-twentieth to one- twenty-fifth of an inch. Tube marked with transverse ridges or annulations, which are sometimes faintly marked on the side opposite to the attached sur- face, and the number of which is fifteen in one-tenth of an inch. Tube in general strongly curved toward its smaller extremity (pi. iv, fig. 3), (2). " Though often occurring in great numbers together, the tubes of Ortonia lor, like those of Ortonia conica, are strictly speaking solitary ; that is to say, they do not, like the tubes of Serpula or Conchicolites, interfere with one another or come into contact except accidentally. The tube is generally pretty nearly circular in section, though sometimes slightly trigonal, conical, and always more or less curved. Sometimes it is simply curved like a horn ; sometimes it is curved like the letter S, and sometimes the smaller extremity is twisted into a flat spiral. I can detect no longitudinal striation, but the tube is covered with very numerous transverse ridges (at least 150 in the space of an inch), which are generally better marked on the sides than on the back of the tube. In very small, presumably young, specimens, I have been unable to deter- mine the existence of these ridges, and even in fully-grown examines they are more strongly marked in some than in others. The tube is always attached along its whole length, and in no case is any portion free, as is the case in ' hicolites. "Locality and formation. Common in the Hudson River group (Lower Silu- rian) of Cincinnati, Ohio, attached to the exterior of Brachiopods and Corals." CEPHALOPODA DESCRIPTIONS OF SPECIES. Note. — The following descriptions and accompanying plates are supplementary to the fossil cephalopoda presented in Volume V, part II. of the Palaeontology of New York. After the completion of that volume, there still remained in the possession of the author, some new or undescribed material, and a number of specimens which were important as illustrating additional features of some of the previously established forms. The descriptions of a number of the species presented on the supplementary plates, were prepared in time to be included in their proper place in the volume. Such species are here rely cited, and referred to volume v, part 2. It has been necessary to restrict the length of the descriptions here given, on account of the contract limitations for the present volume. At the close of Volume V, part ii, in 1879, the Cephalopoda were com- mitted to the charge of Mr. C. E. Beecher, who has furnished the following descriptions : ORTHOCERAS, Breynius. 1732. Orthoceras duramen. PLATE (JXVII, FIG. 1. Orthoceras duramen. Hall. Fifth Ann. Kept. State Geologist. Expl. pi. (117) 1, fijj. 1. lSSti. Shell straight, robust, rapidly enlarging to the chamber of habitation. Apical angle ten degrees. The specimen described is a compressed septate frag- ment, and the true form of the transverse section cannot be ascertained. Initial extremity unknown. Air-chambers 15 to 20 mm. in depth. Septa thin, deeply concave. Sutures straight, marked on the internal mould by narrow depressed zones, as in 0. cingulum (Pal. N. Y., vol. v, pt. 2, p. 240). Siph uncle and test not observed. PALEONTOLOGY OF NEW YORK. The fragment illustrated has portions of eight air-chambers and the base of the chamber of habitation, and measures nearly 160 mm. in length and 67 mm. in diameter at the last air-chamber. This species somewhat resembles 0. Pelops (Pal. N. Y., vol. v, pt. 2, p. 233), but may be distinguished by the comparatively deeper air-chambers and more rapidly enlarging tube. Distribution. In the Schoharie grit, Clarksville, Albany county. Orthoceras sceptrum. PLATE CXVII, FIG. 1. (h! eptrum, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (117) 1, fig. 2. 1SS6. Shell large, straight along the outer chamber and slightly curved in the septate portion, regularly and gradually expanding to the base of the chamber of habitation. Transverse section sub-circular. Apical angle nine degrees. Initial extremity unknown. Chamber of habitation large, cylindrical, slightly contracting near the aperture; length about twice the diameter of the last septum. Air-chambers varying from 5 to 9 mm. in depth in the length of 140 mm., where the diameter of the tube is 40 and 55 mm. respectively. Septa thin. Sutures straight or somewhat curved, the degree of curva- ture being dependent on the amount of the weathering of the fillings of the air-chambers. The appearance of the septa and air-chambers indicates that there was an organic deposit in the apical portion of the specimen, but no distinctive characters can be discerned. Siphuncle sub-central. Test unknown. The individual described consists of the chamber of habitation and about thirty air-chambers, measuring 450 mm. in the entire length, of which 145 mm. pertain to the chamber of habitation. The diameter of the tube near the aperture is 90 mm. and about 30 mm. at the distal extremity of the specimen. CEPHALOPODA. 27 The only related species from the Upper Helderberg group, which also ap- parently has a slight normal curvature in the tube, is 0. Ohiocnse (Pal. N. Y., vol v, pt. 2, p. 236), from which the present form may be distinguished by its larger size and deeper air-chambers. The specimen is a weathered and macerated internal mould, and many of the important specific features of test, ornaments and septa have not been preserved. Distribution. In the Upper Helderberg limestone, at Cherry Valley, Otsego county. Orthoceras directum. PLATE CXV1I, FIGS. «, 7. OrOwceras directum. Hall. Fifth Aim. Rept. State Geologist. Expl. pi. (117) 1. figs. 6, 7. IS86. Shell large, straight, gradually increasing in diameter to near the aperture. Apical angle seven degrees. Initial extremity unknown. Chamber of habitation large ; length one and a half times the diameter of the tube at the last septum. Air-chambers varying from 8 to 12 mm. in depth in the distance of 100 mm. near the outer chamber. Septa thin, moderately concave. Sutures direct. Siphuncle and test not preserved in the specimen described. Internal mould smooth. The specimen consists of the chamber of habitation and twelve attached air-chambers, and has a length of about 250 mm., of which 115 mm. pertain to the chamber of habitation. Figures 6 and 7 of plate cxvii, show in a very marked degree a condition frequently present in fossils of this class. Figure 6 shows the internal mould with the air-chambers well defined and the sutures depressed from the weather- ing of the septa, presenting every evidence of the preservation of the septa and siphuncle. A section of the specimen, represented in figure 7, shows that nearly the entire interior of the shell has been broken away, and that Tenta- culites and other shells were drifted in with the sediments filling the tube. Distribution. In the Corniferous limestone, Delaware, Delaware county, Ohio. 28 PALEONTOLOGY OF NEW YORK. Orthoceras Dagon. PLATE (XXIX, FIG. 1. 'Jtoceras Dagon, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (129) 14, fig. 1. 1S86. Tins species is represented by a large septate fragment, preserving the base of the chamber of habitation with about two-thirds of the air-chambers attached. The entire length of the fragment is 223 mm. Although based on imperfect material, the distinguishing characters are so pronounced as to readily distinguish the species from any other form previously indicated from the same horizon. The principal features are : The rapid enlargement of the tube, with the con- sequent large apical angle ; and the broad retral curvature of the septal sutures on what is probably the ventral side. Distribution. In the Upper Helderberg limestone, Columbus, Ohio. Orthoceras rudens. PLATE CXVIII, FIG. I. Orthoceras widens, Hall. Fifth Ann. Rept. State Geologist Expl. pi. (118) 2, fig. 1. 1886. The species is represented in the collections by a compressed fragment of the chamber of habitation, having a length of a little more than 100 mm. The tube is marked by longitudinal striae and ornamented by numerous regular annulations, of which there are three in the space of 10 mm., showing a well- deli ned retral curve on the ventral side. This form differs conspicuously from 0. crotahm (Pal. N. Y., vol. v, pt. 2, p. 296), and 0. calamen (id., p. 298), in its larger size and comparatively more frequent and depressed annulations. The surface characters more nearly approach those of 0. nuntium (id., p. 299), but the annulations are broader, less abrupt, and the strong retral curve in the ornamentation on the ventral side are not present in that species. Distribution. The type specimen is from an argillaceous limestone, and is recorded as from the Hamilton group, in Livingston county. CEPHALOPODA. 29 Orthoceras expositum. PLATE CXV1II, FIG. 2. Orthoceras expositum. Hall. Fifth Ann. Rr-pt. State Geologist Expl. pi. (118) 2, fig. 2. 1886. Shell large, straight, gradually enlarging to the aperture ; transverse section sub-circular. Apical angle five degrees. Initial extremity unknown. Chamber of habitation long, regularly expanding to the aperture, length more than twice the diameter of the tube at the last septum. Air-chambers 7 mm. in depth where the tube has a diameter of 37 mm., becoming regu- larly shallower toward the apex of the tube. Septa thin, concavity deeper than the depth of the air-chambers. The apical portion of the shell is partially filled with an irregularly vesiculose organic deposit. Siphuncle moniliform. excentric. Test not preserved. The impression of the shell in the rock shows that the surface was marked by lamellose concentric lines of growth. The specimen illustrated has a length of about 300 mm., of which 125 mm. belong to the chamber of habitation. Numerous fragments of this species are preserved in an iron-ore bed, from Bradford county, Pa. The specimens consist of internal moulds in a ferruginous sandstone, or of calcareous shells imbedded in the sandstone. Distribution. In an iron-ore bed of the Chemung group. Canton, Bradford county, Pa. Orthoceras consortale. PLATE CXV1II, FIGS. 3-5. Orthoceras consortale, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (US) 2, tigs. 3-5. 1SSG. Shell straight, rapidly expanding from the apex to near the aperture ; trans- verse section broadly oval. Apical angle ten degrees. Initial extremity unknown. Chamber of habitation not fully shown in the specimens observed, appar- ently short and constricted near the aperture. Air-chambers 5 mm. in :;.. PALEONTOLOGY OF NEW YORK. depth, where the tube measures 28 mm. in greatest diameter. But little variation in the depth of the air-chambers can be noticed in the tube for a Length of 125 mm. Septa thin, deeply concave. Sutures somewhat curved, not deeply im- pressed on the internal mould. Siphuncle moniliform, excentric, distant more than one-third the diameter of the tube from the ventral side. Test marked by irregular lamellose lines of growth, which make a distinct retral curve on the ventral side of the tube. Internal mould smooth. The apical portions of the shell show an organic deposit partially filling the air-chambers; but on account of the preservation of the specimens in a sandstone, its minute characters cannot be described. The specimen illustrated, has a length of 185 mm., with a diameter of 38 mm. near the aperture and 9 mm. at the distal extremity. Individuals of this species are of frequent occurrence in a sandstone at Panama, N. Y., and are better preserved than is usual with other forms of this class from similar deposits in the Chemung group. The species may be dis- tinguished by the rapid enlargement of the tube, the oval transverse section and the position and form of the siphuncle. Distribution. In a sandstone of the Chemung group, at Panama, Chautauqua county. Orthoceras Indianense. PLATE CXVIU, FIGS. 6-10. < hi Inn eras /iiiHiiiu.iisis, Hall. Thirteenth Ann. Rept. N. Y. State Cab. Nat. Hist., p. 107. 1S60. Orthoceras Dcedalus, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (118) 2, figs. 6-11. 1886. Shell small, straight, slender; transverse section circular. Apical angle six degrees. Initial extremity unknown. Chamber of habitation long, gradually enlarging from the last septum for two-thirds its length, and then contracted by a broad constriction, from which the tube enlarges to the aperture. Air-chambers regular, very gradually increasing in depth to the last septum, six in the length of 22 mm. where the tube measures respectively 9 and 12 mm. in diameter. CEPHALOPODA. 31 Septa thin, moderately concave. Sutures straight, not deeply impressed. Siphuncle sub-central. The elements of the siphuncle have not been observed, except at its passage through the septa, where it is very small, having a diameter of not more than 1 mm. where the tube measures 15 mm. in diameter. Test not preserved. Internal mould smooth. Septa marked with an areola around the siphuncle and a concentrically marked, ovate, organic deposit extending from the siphuncle to the ventral walls of the air-chambers. The chamber of habitation of a specimen has a length of 54 mm., and a diameter of 14.5 mm. at the last septum. A fragment containing nine air- chambers and the base of the outer chamber measures 29 mm. in the length of the septate portion, and is 9 mm. in diameter at the smaller extremity. This species may be distinguished from 0. Icarus, by its sub-central siphuncle, the comparatively deeper air-chambers, and the more marked constriction of the tube near the aperture. Distribution. In the Goniatite limestone, at Rockford, Indiana. Orthoceras Icarus. / PLATE CXVIII, FIGS. 11-15. Orthoceras Icarus, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (US) 2, figs. 11-15. 1SSC. The specimens of this species bear so close a resemblance to those of 0. Indianensis, that a statement of differences will be more satisfactory than a detailed description. In this species the air-chambers are comparatively much shallower than in 0. Indianensis, the siphuncle is excentric, and in the specimens observed there is a greater amount of organic deposit surrounding it. The internal mould of a small fragment shows a line of strong nodes along the ventral side of the tube. A chamber of habitation has a length of 53 mm. with a diameter at the aperture of 23 mm., and of 18 mm. at the last septum. Distribution. In the Goniatite limestone, Rockford, Indiana. PALEONTOLOGY OF NEW YORK. GOMPHOCER AS, Sowerbt. 1839. GOMPHOCERAS FAX. PLATE (XXII, FIG. 5. Gomphoceras fax, Hall. Pal. N. Y.. vol. v, pt. 2, p. 321. 1879. GOMPHOCERAS ILLJENUS. PLATE (JXXII, FIG. 6. Gomphoceras Illacnus, Hall. Pal. N. Y.. vol. v, pt. 2, p. 322. 1879. Gomphoceras absens. PLATE CXXII, FIGS. 1-3. Oomph'" i ins absens, Hall. Pal. N. Y.. vol. v, pt. 2, p. 324. 1N79. GOMPHOCERAJ EXIMIUM. PLATE CXX, FIGS. 1-3 ; AND PLATE CXXI, FIGS. 1, ■>. Gomphoceras eximium, Hall. Pal. N. Y., vol. v, pt. 2, p. 329. 1879. Gomphoceras mitra. PL \TK IXIX, FIG. 1 ; and PLATE CXXI, FIG. 3. Gomphoceras mitra, Hall. Pal. N. Y.. vol. v, pt. 2, p. 330. 1879. Gomphoceras impar. PLATE CXX, FIG. i ; AND l'LATE CXXI A, FIG. 1. Gomphoceras impar. Hall. Pal. N. Y., vol. v, pt. 2, p. 332. 1S79. Gomphoceras cammarus. PLATE CXXII, FIG. 7. Gomphoceras cammarus, Hall. Pal. N. Y., vol. v, pt. 2, p. 333. 1879. Gomphoceras gomphus. PLATE CXXIII, FIG. 1. Gomphoceras yomphits, Hall. Pal. N. Y., vol. v, pt. 2, p. 334. 1879. CEPHALOPODA. 33 GOMPUOCERAS CRENATUM. PLATE CXXI A, FIG. i ffo wphoceras crenatvm, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (1-1 a) 6, fig. 2. 1886. Tins species is based upon a specimen consisting of the chamber of habita- tion and a portion of ten attached air-chambers. The point of greatest trans- verse section is at about the second septum from the outer chamber. Chamber of habitation a little longer than the transverse diameter, gradually contracting to the aperture. The base of this chamber is marked by a zone of strong elevated lines, distant from each other about 4 mm. and extending over the walls of the air-chambers. Air-chambers about 7 mm. in depth in the main body of the tube. The specimen described has a length of 121 mm., of which 50 mm. pertain to the chamber of habitation. The greatest transverse diameter of the tube measures 56 mm. Distribution. In the limestone of the Upper Helderberg group, Columbus, Ohio. GOMPUOCERAS PLENUM. PLATE CXXI A, FIGS. 3, i Gomphoceras plenum. Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (121 a) 6, figs. 3,4. 1886. Shell large, stout, sub-fusiform. Transverse section circular ; point of greatest gibbosity at about the tenth septum from the chamber of habitation. Axis nearly straight. Tube rapidly enlarging to the point of greatest transverse section, more gradually contracting to the outer third of the grand chamber, and abruptly constricted at the aperture. Chamber of habitation as long as the diameter of the tube at the last septum. Aperture obscurely trilobate. Air-chambers from 6 to 7 mm. in depth over the larger portion of the shell; the last three being shallower. Sutures slightly curved. Siphuncle situated near the ventral side of the tube ; its elements in the inter septal spaces have not been observed. 34 PALEONTOLOGY OF NEW YORK. Test not preserved Internal mould smooth. The specimen described consists of the chamber of habitation and fifteen air-chambers, and measures 145 mm. in length and 64 mm. in greatest trans- verse diameter. Distribution. In the Upper Helderberg limestone, near Columbus, Ohio. O.OMrilOCERAS AIINUM. PLATE CXXIt, FIG. 4. Gwnphoeeras mtoium, Hall. Fifth Ann. Kept. State Geologist. Expl. pi. (122) 7, fig. 4. 1883. Shell small, oviform; point of greatest transverse section on the anterior third of the tube. Chamber of habitation comparatively large and gibbous. Aperture small, trilobate. Air-chambers 2 mm. in depth. Test marked by lines of growth. Length of specimen 30 mm., greatest diameter 22 mm. The shell of the individual described is silicified and many of the features are obscure. The species is distinguished by the small and ovoid shell. Distribution. In the limestone of the Hamilton group, from the Falls of the Ohio River, near Louisville, Ky. GOMPHOCERAS MANES. PLATE CXXIII, FIG. 1 Gomphoceras manes, Hall. Pal. N. V.. vol. v. pt. 2. p. 339. 1879. GOMPHOCERAS NASUTUM. PLATE CXX, FIGS. 5-7. a ,h . a nasutum, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (120) 4, figs. 5-7. 1886. SHELL small, robust, nearly straight. Tube rapidly expanding to the middle of the chamber of habitation thence gradually contracting to the aperture. CEPHALOPODA. 35 Chamber of habitation shorter than the transverse diameter. Grand aper- ture large, oval, with a marked sinus on the ventral side, forming a small aperture. Crenulated zone narrow, marked by fine elevated transverse lines or nodes. Air-chambers shallow, having a depth of 2.5 mm. near the outer chamber. Sutures straight, with the exception of a slight retral bend on the ventral side adjacent to the siphuncle. Siphuncle small, ventral, situated close to the walls of the air-chambers. Surface marked by irregular lamellose lines of growth which become aggre- gated into fascicles near the aperture. Internal mould smooth. A fragment preserving the chamber of habitation and four attached air- chambers has a length of 30 mm., and a greatest diameter of 28 mm. Distribution. In the arenaceous shales of the Chemung group, at Belmont and Belvidere, Alleghany county. GOMPHOCERAS POTENS. PLATE CXXII, FIG 8. Gomphoeeras patens, Hall. Pal. N. Y., vol. v, pt. 2, ;>. 351. 1S79. CYRTOCERAS, Goldfuss. 1832. Crytoceras subcompressum. PLATE CXXIX, FIGS. 2, 3. Cyrtoeeras subcompressum, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (129) 14. tigs. 2. 3. 1SS6. Shell large, robust, exogastric, curved, a mature individual making a quadrant of a circle. Transverse section broadly oval. Tube regularly enlarging from the apex to the aperture. Chamber of habitation large. Air-chambers regular, about 7 mm. in depth. Siphuncle nearly one-fourth the diameter of the tube, excentric, nummu- loid, abruptly contracted at its passage through the septa. 36 PALAEONTOLOGY OF NEW YORK. Test and surface ornaments unknown. A large specimen, preserving nearly the entire length of the tube, meas- ures 215 mm. on the periphery, and 80 mm. in diameter at the last septum. The specimens described are internal moulds preserved in a coarse lime- stone, and the external characters are not shown. Distribution. In a limestone of the Clinton group, Piqua, Ohio. Cyrtoceras Jason. PLATE CXXIV, FIG. 7. Cyrtoceras Jason, Hall. Pal. N. Y., vol. v, pt. 2, p. 3S1. 1879. Cyrtoceras citum. PLATE CXXIV, FIGS. 1-3. Cyrtoceras citum, Hall. Pal. N. Y„ vol. v. pt. 2, p. 372. 1S79. GYROCERAS, De Koninck. 1841. Gyroceras Nereus. PLATE CXXIV, FIG. 4 Gyroceras Nereus, Hall. Pal. N. Y., vol. v, pt. 2. p. 373. 1S79. Gyroceras laciniosum. PLATE CXXIV, FIGS. 5, 6. Gyroceras laciniosum, Hall. Pal. N. Y., vol. v, pt. 2, p. 376. 1S79. Gyroceras ? Stebos. PLATE CXXVI, FIG. 7. Gyroceras Stebos, Hall. Fifth Ann. Rept. State Geologist. Expl pi. (126) 11, fig. 7. 3SS6. Several specimens of this species have been obtained from the Waverly sand- stones in Pennsylvania. The general form and appearance is that of a shell belonging to the genus Gyroceras, although no traces of septa are preserved. The ventral or peripheral side shows a longitudinal groove, which may be of CEPHALOPODA. 37 siphuncular significance. In other characters it resembles sonic described species of gastropoda belonging to the genus Porcelli a ; bul with the present material it is difficult to make a satisfactory determination. The specimen illustrated shows three volutions and measures 1(H) mm. in greatest diameter. Distribution. In the sandstones of the Waverly group, Warren county, Pa. TrOCHOCERAS ? (Go.MOCERAS I) PANDUM. PLATE CX\ II. FIGS. 3-5. Trockoeeras .* (ffonioeera. pandum, Hall. Pal N. V.. vol. v. pt. 2, p. 4iU. pi. iii. fig. -t. 1879 No additional specimens of this species have been obtained since the original publication in 1879, and its generic relations are still uncertain. In addition to its comparison with some associated forms of Trochoceras from the Schoharie grit, as noticed in Pal. N. Y., vol. v, pt. 2, p. 403, it may also be compared with Gomphoceras fax. illustrated on plate exxii. NAUTILUS, Breynius. 1732. Nautilus oriens. PLATE CXXVI, FIG. 2. Nautilus oriens, Hall. Pal. N. Y., vol. v. pt. 2, y. 4'jn. 1879. Nautilus Hyatti. PLATE CXXVI, FIG. 1. Nautilus Hyatti, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (126) 11, fig. 1. 1886. In its general characters, this species is closely related to N. burinum (Pal. X. Y.. vol. v, pt. 2, p. 412). The shell is more rapidly expanded than in that species, especially toward the apex. The volutions are free. The transverse section is sub-circular in the apical portion of the shell, broadly oval through the chamber of habitation, and with no dorsal sinus produced by the contiguity of the volutions as in N. bucinum. The specimen is an external mould preserved in an argillaceous concretion, and the form and surface characters of the shell are well preserved. The sur- 38 PALEONTOLOGY OF NEW YORK. face ornaments do not differ materially from those in some varieties of N. buci- num and N. liratus (Pal. N. Y., vol. v, pt, 2, pp. 407, 412). Distribution. In the shales of the Hamilton group, near Cumberland, Md. Nautilus parallelus. PLATE CXXVI, FIGS. 3-5. Haul elus, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (126) 11, tigs. 3-5. 18S6. Shell small, gradually enlarging to the aperture ; volutions not emhracing. Transverse section lenticular, with acute lateral angles. Chamber of habitation nearly twice as long as the transverse diameter, mtv gradually expanding to near the aperture, which is constricted. Siphuncle sub-central. Surface marked by fine lines of growth and by elevated longitudinal lines or slender ridges, which are distant from 2 to 3 mm. The chamber of habitation has a length of 60 mm. on the ventral side and a transverse diameter of 20 mm. at the last septum. The ventro-dorsal diameter at the same point is 16 mm. The single imperfect specimen representing this species in the collection, was recorded as doubtfully from the Chemung group, at Salamanca, N. Y. The character of the rock and general appearance of the specimen do not agree with other fossils obtained from that locality, but closely resemble specimens from the coal measures of Ohio. It is probable that the specimen was misplaced in the collections and erroneously referred to the Chemung group of New Yrork. Tin' species also represents a Carboniferous type of Nautilus, and is related to tin- pi i us Temnocheilus, Meek, and to species classed as Gyroceras by De Koninck, obtained from the Carboniferous rocks of Belgium. Distribution. Probably from the coal measures of Ohio. Nautilus (Discites) Ammonis. PLATE CXXV, FIG 1. ammonis, Hall. Pal. N. Y.. vol. v, pt. 2, p. 425. 1879. CEPHALOPODA. 39 Nautilus (Discites) Marcellensis. PLATE I XXVI, FIG. 6. Nautilus (Discites) Marcellensis (Vanuxem), Ham. Pal V v.. vol. v, pt. 2, p. 428. 1879. GONIATITES, De Haan. 1825. GONIATITES VANUXEMI. PLATE (XXVII, FIGS. 3-6. Goniatites Vanuxemi, Hall. Pal. N. V., vol. v, pt. 2, p. 4::4. 1879 Goniatites Vanuxemi, var. nodiferus. PLATE XXVII, FIG. 7 [fifes V'titu r, mi, var. nodiferus, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (127) 12, fig1. 7 1886. Several specimens of Goniatites have been obtained from the shales of the Hamilton group which agree in all essential features with the characteristic species of the Marcellus shales, G. Vanuxemi (Pal. N. Y., vol. v, pt. 2, p. 434). They are indicated as a variety on account of a row of distinct rounded nodes around the dorsal or inner third of the periphery of the volutions. Distribution. In the shales of the Hamilton group, at Cherry Valley, Otsego county. Goniatites discoideus. PLATE CXXVII, FIGS. II, 12. Goniatites discuidnts. Hall. Pal. N. Y., vol. v. j >t . 2, p. 441. 1879. Goniatites uniangularis. PLATE CXXVII, FIG. 10. Goniatites uniangularis (Conrad), Hall. Pal. N. Y., vol. v, pt. 2, p. 144. 1879. Goniatites amplexus. PLATE (XXVII, FIG. 1. Goniatites amplexus, Hall. Fifth Ann. Rept. Stat.- Geologist. Expl. pi. (127) 12. fig. 1. 1886. Shell small, discoid. Volutions slender, rounded, embracing to the depth of nearly one-half of their dorso-ventral diameter. Umbilicus large, open. in PALEONTOLOGY OF NEW YORK. Chamber of habitation large, constituting nearly the whole of the outer volution. Sutures with two deep lobes and one saddle on each side of a volution, and a small acute saddle adjacent to the siphonal line. Surface marked by regular lamellose concentric lines, curving forward from the umbilicus to the ventral side. The specimen described has a greatest diameter across the disc of IS mm. The lateral diameter of the tube at the last septum is 6.5 mm. Distribution. In the Tully limestone, at Lodi Landing, Seneca Lake. GONIATITES COMPLANATUS. PL VTE < .XXVI], FIG 2. at.iUs complanatus. Hall, Pal. N. Y., vol. v. [it. 2, p. 4")."). isT'J. GONIATITES FJNUOSUS. PLATE CXXVIII, FIGS. 1,2, Goniatites shitumis. Hall. Pal. N. V., vol. v. pt. 2. p. 460. 1879. GONIATITES PaTERSOM. PLATE CXXVII, FIGS. 8,9. Goniatites Patersoni, Hall. Pal. N. Y,. vol. v, pt. 2. p. 4H4. 1879. Goniatites Oweni. I'LATE CXXVIII, FIGS. 4-7. Goniatites (hoeni, Hall. Pal. N. Y., vol. v, pt. 2, p. 470. 187'.). Goniatites Ixion. PLATE CXXVIII, FIG .; Goniatites Ixion, Hall. Pal. N. Y.. vol. v, pt. 2. p. 474. 1879. INDEX IX) THE GENERA AND SPECIES DESCRIBED OR NOTICED IN PALAEON- TOLOGY OF NEW YORK, VOL. V, PART II, SUPPLEMENT. The heavy faced number; denote the place of description.] PAGE PAGE. ( ul EOLI S, Hull, 7. :i Gomplioceras eximium, Hull, 32 1 llcrzcn, //«//, 7 G. Hall. . 32 COLEUI'RIOK, ... 9 G. lax, Hall, . 32 COSCUWHOUTES S •.i. 17. 22, .'.'., ■24 G. fax, Hall, 32 C. corruyatas, Nicholson, 12, 17, 23, 24 G. gomphus, Hilt. 32 1 ,-, Nicholson. .. 24 <: gomphus, Hall, 32 Corkui.ites, Schlotheim, 1, 1-. 21, 23 G. II ki-nu-. Hall, 32 Cornulitcs, Hall, 1-. 20 u I litmus. Hall, 32 ■ arcnatns, Conrad. 19 G. impar, Hall 32 areuatus, Conrad, . 19 G impitr, Hall, 82 i areuatus, (ConreKi] i/«//. 19 G. manes, Hall, 34 1 uellastrialus, Hull. IS 1!) G. manes. Hall. .... U C chrysalis, //«//, •io G minuni, Hall, 34 1 Oingnlatus, Hatt, 2C G. minum. Hall. . . 34 i Clintoni. /7«tf. Ml G. iiiitra. Hall, 32 c Clintoni, Hall, 19 <; mitra, Hall. . 32 1 ■ 'berg. 19 G. nasutum, Hall, 34 c distans, //-///. to. 211 G. nasutum, Hall, 34 ■ Qcxuosus, //a//, IS G. plenum, Hall, 33 i jlexuosus. Hall, is. v.\ '.' plenum Hall, . 33 • incnrvus, {Shumartl Hall, 18 G. potens, Hall, 35 i nodosus, Ilinyueberg, 19 G. ■ Hall. 15 u. proprius, 7/nM, . 19 GoNIATITES, Hi Haan. 39 c projtrius. Hall, la G. amplexns, Hall, . 39 1 serpnlarins, Murchison, 12, 21. J'.', 2:; '.' amplexus, Hall. :;'.' 1 scrpuiarius, Schlotheim, g 13 G. - planatns, IL'II. 40 u. tribal is, //«», . 30 '. complaiiatus, Hall, 4CI ' tema bilix, Conrad, . 24 i . discoidcus, //"//. 39 V. (1'leui [ix, Conrad, 24 '; discoidcus, Hall, ■:,:i I'l KT LS 'truss, 35 G Ixion, Hall, . 40 1 cilam, Hall, 36 G Ixion, Hall, 40 c. citum, Hall, 36 (. i Iweni, Hall. . 40 c. Jason, Hull, 36 G Oioeni, Hall, 4H c Jason, Hall, 3fi '. l'aiersoni. Hall. . 40 c subcompressum, ifott, 35 '. I'atersoni, Hall, 40 c subcompressum, Hall, 35 G. sinuosns, Hall, . 40 Echinus gyracanthus, Eaton, 5 1 iinuosus, Hall, l» n>tocrinus crassns, . 15 i. uniangulari 3, (Con . 39 Gompi ia-. Sowerby, 32 '.' " niangulari8, Hall, 39 G //a//. 32 G Vanuxemi, //"//. . 39 G. ubsens, Hal], 32 '.. i anuxt mi, Hall, . 3'.! G cammarus, ffatt, . 32 G. Vanuxemi, \.n. nodiferas, JIull, 39 oommartM, Hall. 32 '. Vanuxemi, vttx nodi/erus, Hall, 39 '. crenatam, fiaR, 33 g\ kocer \~. De Koninck, 31'.. IS ',' crenntiiiii. Hall. 33 |. laciniosnm, Hall, . :tc 12 INDEX. mm, Hall, I , N'eieil., Hall, is, Hall, 5te Hall, .. Hall, llioi 1 1 in s Eichviald, it Hnuilis, Barrett, II centcnninli Barrel] Hall, ii Hull, \ At uits, Breynius, N bucinum, \ Ifyiitti, Hall, V. EfyaHt, Hall, N liratus, \ oricns, HoK, V oriens, Hall, N pnrallelus, J7oU, V parallelus, Hall, N. (Discites) Ammonis, 7/ ) Ammonis, Hall N. t [). i Marcellensis, i Pawn " "' _\' /» flfarceMensis, (Vanuxem) Olfl RAS, l:r,;iniux, it ca'lamcn, 0. cingulum, it consnrtale, /7««, i >. consortale, Hall, <> crotalum, 0 Dcedalus, Hall, u Dagon, HaH, 0. 7w..m. Hall, . 1 1 directum, Hall, n directum, Hall, 0. duramen, 77«//, 0. duramen, Hall, ' i exposltnm, Hall, . 0. expositum, Hall, n learns, HffiK, " Teams, Hall, 0 Indianensis, flaH, 0 hulianrn.fis, Hall, 0 nuntium, O. Ohioonso, ' ' Pelops. 0. rudens,^J7a?2, 0. i ■»•/, n;, Hall.l] Hall, Hall 17, 37, PAGE. 36 36 36 36 36 6, SI 6 6 7 88 38 37 37 38 37 37 38 38 38 hs 39 39 2a •:r margin. ' i tal drawn from a cast of the lower surface and showing the im- i tenor margin. The annulations upon the posterior por- iious in the drawing, grit. Schoharit county. ' dge has been broken away in the specimen, leaving the ate than is normal. Schoharie hoharii con Calym EN B NlAGARENSIS. showing the first .and inconspicuous third pair of glabellar lobes. Inti i : . ■ ill,,, „, platys. Iron, I ml 'num. <■■ cephalon, showing the epi tomal doublure and the hypostoma in place, i, Indiana. Pig. 12. .'-. ize. Waldron, Indiana. mowing the upper surface of the hypostoma. 1 • a two diami ira group. Waldro . Tnd; 1 1 . 1 1 i - ( t i*i 1: . I UAI.YN ' PLATE II. HoMALONOTUS DeKAYI. Page 7. See Plates 3, 4 and 5. individual, showing' a strongly annulated and trilobate lium. Hamilton group. Madison county. tly trilobate and nearlj entire individual. Hamilton gn -|>. La y, near /Sherburne, Chenango cov/nty, fa somewhat larger, enr lied individual, me. Hamilton group IS ■ Madison county. Fiw. ;". An individ i iii more ad I of growth, retaining the trilobate pygidium. The i. what restored upon the leftside. Kami ■. Onondaga county. and uncompressed individual, preserved as an internal cast. Han ip. Madison o/r Otsego* county. le average normal adult size attained by specimens from the arenaceous is preserved a- a cast of the lower surface, and shows the conspicuous trans\ ipou the segments of the thorax. The annulations of the pygidium are much more than they are made to appear in the drawing. Hamilton group. Mi it;/. 8. An | nowing bu1 ten, instead of thirteen thoracic segments. The cephalon has ap- par< pushed back so as to cover the first three segin. evation of the body and the prolongation of the anterior and Hamilton group. Madison county. ierfec1 cephalon. Hamilton group. East Worcester, Otsego county. I 1. A cephalon (Vein the soft shales, in which the facial suture is somewhat thrown backward at the the crushing of the frontal doublure. . The anterior portion of the suture is more transverse in the specimen than is represented in the drawing. Han up. Darien, Genesee county. : Hamilton group Ca wnna, Madison county. alaeonlology ithfli. PLATE III. HOMALONOTUS DeKAYI. See Plates 2, 4 and 5. Fie 1 A small individual from the soft shales, retaining a portion of the crust and showing the median frontal plate enclosed by the branches of the facial sutures upon the epistomal doublure. In the drawing the ampliations of the pygidium are too strongly represented. Hamilton group. Bellmw, Yates county. ■2. A cast of the lower surface of a larger individual, showing the median plate and a portion of the hypostoma displaced from its normal position. Hamilton group. Near Leonard&Alle, Madison county. Pig. 3. A cast of the lower surface of an almost entire specimen. Hamilton group. Madison county. Fig. 4. A specimen from the soft shales, retaining twelve thoracic segments with the pygidium, and pre- serving the crust. Hamilton group. Canandaigua Lake. Fig. :,. A I. lock of arenaceous shale, showing tin- dismembered [.arts of a large individual. Hamilton group. Madison county. ■ I I' \1.Y\I I \ II). K I • PLATE IV. HOMALONOTUS DeKAYI. See Plates 2, 3 and 5. Fig-. 1. Profile view of an unusually large enrolled individual, a cast of the lower surface. Anterior aspect of the same, showing- the pygidial doublure. Posterior aspect of the same. Hamilton group. Madison eowity. Dorsal aspect of a normal cephalon. Lower aspect of the same, showing- the doublure, the branches of the facial sutures and the median frontal plate. Hamilton group. Madison county. Fig-, tj. An enlargement, to five diameters, of the under surface of the test, of a specimen from the soft shales, showing the openings and projecting edges of the large vertical tubules. Hamilton group. Canandaigua Lake. Fig. 7. A similar enlargement of the under surface of a specimen from the limestone, showing the ele- vated edge of the tubules and the openings of the minute tubulipores. Hamilton group. Canandaigua Lake. Fig. 2. Fig. 3. Fig. 4 Fig. 5 li^iO^JXtf £>JiD ( I'AI.l MKN . ilaeontology of N Y VolVII PLATE V. HoMALONOTUS DlCKAYI. See Plates 2, 3 and 4. Fig i. A verj young individual, showing the faint lateral furrows on the glabella. Hamilton group. Pratt's Falls, Onondaga county. Pig. 2. Profile view of an un npressed, partially enrolled, entire individual, retaining the crust and the visual surface of the eyes. Fig. :'.. Front view of the same, showing the elevation of the eyes. From the limestone of the Hamilton group. Canandaigua take. Fig. 4. Profile view of an enrolled and compressed specimen from the shales. Fig 5. Anterior aspect of the same. Fig. 6. Posterior aspect of the same. Hamilton group. Western New York. Fig. 7. A cephalon of medium size. Fig. S. Profile view of the same. Hamilton group. Madison county. Fig. 9. An imperfect cephalon. This specimen is the original of Eaton's Nnttainia sparsa and was obtained by the author in March. 1832. at Stephen's Mill in the town of Coeymans, Albany comity. The occipital ring was regarded by Eaton as the anterior border of the head, corres- ponding to that of Trin net i us (Nnttainia) concentricus. (See Eaton's Geological Text-book, page 34, 1832.) Fig. 1(1. A small pygidium from the limestone, retaining normal convexity. Fig. II. Profile view of the same. Hamilton group. Pratt's Falls. Onondaga county. Fig. 12. Profile view of a pygidium, a cast, of the lower surface. Fig. 13. Dorsal aspect, of the same, showing the usual character of the annulations. Hamilton group. Madison county. Fig. 14. A c:ist .if the lower surface .4' a pygidium upon which the annulations are abnormally distinct for so advanced a stage of growth. Hamilton group. Madison county. ( CAI.YME N 2SS PLATE Va. HOMALONOTUS MAJOR. Page 4. i 1 i irger of the two specimens known, retaining-, as a cast of the lower surface, the pygidium in a slightly distorted condition, and seven thoracic segments, with portions of three others. A restoration of the original length of the animal is carried out in outline in order to give a con- ception of the greal size attained by the species. Oriskany sandstone. Bank of the 4th Binnewater, Rosendale, Ulster county. PLATE Vb. HoMALONOTUS VaNUXEMI. Page 11. Pis'. 1. Dorsal view of a fragment of a very large individual retaining the thorax entire and portions of eleven thoracic segments. The dorsal portion of the thorax has been removed by exposure to the weather, but the remaining parts retain their normal convexity. The pygidium is slightly distorted in the original, but is represented in the figure with its natural proportions in order to allow the restoration in outline of the wanting- parts. In this restoration the character of the cephalon is derived from a single fragment obtained at Port Jervis, Orange county. Fig. 2. Profile of the same, showing the convexity of the body, the extremely long and broad articu- lating surfaces of the thoracic segments, and the abrupt slope of the post-axial area. Lower Helderberg group. Kingston, Ulster county. •• i EEgui, aianm?. flintologyofNYyoMI./ PLATE VI. Phacops CRISTATA. Page 14. See Plate 8 \ Fig. 1. 'I'll'- eephalon. A cast of the lower surface, somewhat flattened and restored at the left genal angle. Schoharie grit. Knox, A ■ ity. Fig. 2. Profile view of another eephalon. \ ca '. slightly flattened upon the glabe Schoharie grit. Near ClarksviUe, A a ity. Fig-. :!. Profile view of an uncompressed eephalon, showing the normal convexity ami the tronggenal spine. Fig. 4. Dorsal aspect of the same. S i iharie grit. Near ClarksviUe, Albany county. Pig. 5. Lower aspect of a eephalon, showing the protuberance of the glabella, the frontal sulcus arid epistoma. The drawing fails to represent the crenulations upon the sulcus near the- genal extremitie Schoharie grit. Schoharie, St ounty. Fig. ti. Profile view of a small eephalon : a BUS* of tin- interior. Fig. 7. Dorsal aspect of the sai Schoharie grit. A '//. Fig. 8. A cephJtlon referred with iloufet to this species: Schoharie grit. A ity. Fig. 9. A fragment of a young- individual. 51 of the thorax and pygidium and retail ing the crust, Tin- ape -i in. • r 1 is enlarged to two diameters and shows the axial row of spines, oharie grit. Near ClarksviUe, A mty. Fig. 10. A nearly entire individual, drawn from an impression obtained from a natural mould of the doreal surface. In the drawingthe/axial spinesiand the right genal spine are net given sufflciertl prominence. Schoharie grit. Albany county. Fig. 11. A fragment retaining a portion of the thorax ancj jjygidium, showing the axial spines and the duplicate pleural, ambulations on the pygidium. Corniferous limestone! Indian quarries', Ononddpa.cmi Fig. 12. A pygidium retaining a portion id' the crust and showing the charaeter of 'the pleural aunulatii Fig. 13. Profile view of the same. Schoharie grit. ScTioharie, Schoharu county. Fig. 1 » '> . A eephalon retaining the normal convexitj of the glabella and impressions ol the tubercles upon its surface, but not showing the occipital or the cheek-spines. Fig. 17. Front view of the same. Fig. 20. The under surface of the same. Fig. 21. Profile view of the same. Corniferous limestone. Helderberg mountains. Fig. 18. A eephalon denuded of its crust, and showing the cheek-spines. Fig. 19. Profile of the same, showing the crenulations upon the frontal sulcus. t !< irniferous limestone. Fig. 22. A smaller eephalon. retaining normal convexity and showing the tubercles upon the glabella. Fig. 23. The under surface of the same, showing the broad doublure. The crenulations upon the lateral branches of the frontal sulcus are not made sufficiently conspicuous, and they do not appear on the frontal limits of this sulcus, as represented in the drawing. Upper Helderberg limestone. Clarence Hollow, Erie county. Fig. 24. A small eephalon partly denuded of its crust, showing strong genal s] Fig. 25. Profile view of the same. Upper Helderberg limestone. Cayuga, Province of Ontario. PLATE VI— Continued. Fig. 26. A fragment of a cephalon, showing the hypostoma in place. Schoharie grit. Schoharie, Schoharie county. Fig. 27. A cast of the lower surface of :i pygidium, showing traces of the grooves upon the pleural aimu- lations. Schoharie grit. Near Clwrksville, Albany comity. Pig. 28. A rust df a larger pygidium, showing the simple pleural annulations ; their usual appearance in an impression of the lower surface. Upper Helderberg limestone. SchiMz's farm, near Clarence, Erie comity. Fig. 29. A very large pygidium in the same condition of preservation. Schoharie grit. Schoharie, Schoharie county. Phacops RANA ? Fig. 14. Dorsal view of a specimen retaining the parts in juxtaposition. The head is slightly displaced and somewhat imperfect. Fig. 15. Profile of the same, showing the elevation of the body. Upper Helderberg limestone. Ohio. Palasi i >\ ' S ■ % 15 26 ''" ""'^'V 21 17 2? 23 28 22 -^ PLATE VII. Phacops rana. Page 19. See Plates 6, 8, 8 a, and 25. Fig. 1. A specimen of average size, retaining the crust, and showing the general characters of the species. Hamilton shales. Geneseo, Livingston county. 2. A somewhat smaller specimen, retaining the parts in juxtaposition. Hamilton shales. Eighteen-mile Creek, Erie county. Fig. 3. Anterior view of a large, enrolled individual. Fig. 4. Posterior view of the same. Hamilton shales. Canandaigua Lake. Fig. 5. Anterior view of a still larger, enrolled specimen. Hamilton shales. Darien, ffenesee enmity Fig, >'>. A somewhat imperfect eephalon of a very large individual. Hamilton shales. Near Geneseo. Livingston county. Fig. 7. A specimen showing two individuals of nearly equal size, lying one upon the other. Fig. S The same, with the upper individual removed. The emarginate outline of the pygidium in the lower specimen is due to compression, and the sulci represented on the annulations of the left pleura do not exist. Hamilton shales. Canandaigua Lake. Fig. 9, A large individual partly restored on the left side. Hamilton shales. Canandaigua Lake. Fig, 10. A very large, entire individual. This is the largest entire specimen yet observed. Fig 1 1. Profile of the same, showing the glabella flattened from compression in the shales. Hamilton shales. Canandaigua Lake. s&EL'Ls'xris trj^ 'alaeontolos i ;>/;:•■,. ', - - PLATE VIII. Phacops rana. See Plates 6, 7. 8 a, and 25. Pig. I. A young individual, enrolled and showing two pairs of lateral furrows upon the glabella. Fig-. 2. Profile view of the same. Pig. 3. Front view of the same. Hamilton group. Moscow, Livingston county. Fig. 4. Profile view of a small eephalon, Bhowing normal proportii Pig. 5. Dorsal view of the same, showing the glabellar furrows. Fig. 6. An eye of the same enlarged. Hamilton group. Eighteen milt Oreek, Er'u county. Kilt. 7. A young, enrolled individual, showing the glabellar furrows. Hamilton group. Eighteen-mile creek, Er'u county. Pig. 8. Profile view of an enrolled, slightly crushed specimen. Fig. 9. Dorsal view of the same. Hamilton group. Widder; Province of Ontario. Fig. 10. A larger, enrolled individual. Hamilton group. Canandaigua Lake. Fig. 11. A nearly entire, young individual. Hamilton group. Darieri, Gferies'ee county. Fig. 12. The eye of a small individual, enlarged to three diameters, showing- more numerous lenses than in advanced stages of growth. Hamilton group. Eightet n-uiili Creek, Erie county Pig. 13. The eye of a larger individual, showing fewer lenses (similarly enlarged). Hamilton group. Oeneseo, Livingston county. Fig. 14. The eye of a slightly weathered specimen, showing the cavities left by the removal of the lenses (similarly enlarged). Hamilton group. Near Gfeneva, Ontario county. Fig. 15. An obliquely compressed ami distorted specimen, showing a common mode of occurrence, Hamilton group. Canandaigua hake. Fig. 16. A large, entire eephalon. Pig. 17. Profile view of the same. Hamilton group. Canandaigua Lake. Fig. 18. A fragment of the under side of the eephalon, showing a portion of the hypostoma in place. Hamilton group. Jaycox's Rim, near Gfeneseo, Livingston county. Phacops Cacapona. Page 27. Fig. 19. Dorsal view of a somewhat worn internal east in chert. Hamilton group. Mouth of the Cacapon river, Virginia. Fig. 20. Profile of another example, similarly preserved. Fig. 21. Dorsal view of the same. Hamilton group. Mouth of tin Cacapon rim: Virginia. Fig. 22. Front view of an enrolled specimen, referred with some hesitation to this specie Fig. 23. Dorsal view of the same. Fig. 24. Profile view of the same. Hamilton group. Locality doubtful. PLATE Vm— Continued PhACOPS I'.ITO Page -'>;. Fig. 25. Dorsal view of a plaster cast of Dr. Green's type specimen. Fig. 26. Profile view of the same. Hamilton group. The original is said to have come from a dark-grayish limestone in New Jersey. PlIACOPS NUPERA. Page 27. Fig 27. The type specimen, showing the cephalon and thorax. Chemung group. Chemung Creek, Chemung county. palaeontology ol ( PHACOPIIl.i'. ) U '<3> is 14 23 PLATE VIII a. I'll ICOPS CRISTAT v. See Plate t>. Fig. 1. Thorax and pygidium, drawn, fr a gutta percha impression of a natural mould of the doi-sal surface. The specimen is somewhat compressed laterally. Pig. 2. Profile of the same, showing the elevation of the axial row of spines Schoharie grit. .1 'bany county. Pig. '■<■ The under portion of the cephalon, showing the epistomal doublure and the crenulations of the sub-frontal sulcus. Schoharie grit. K/mr, I ity. Pig. 4. An internal cast of the cephalon, enlarged one diameter; a portion of each cl k has I n broken :iwa\ i" show the sub-frontal crenulations. Schoharie grit. Clarisvilte, Albany county . PhaCops cristata, var. i'ipa. Page 18. Pig. 5. Anentire, but somewhat crushed young individual, showing the proportions of this variety, and ilif genal spines. (Villiferous limestone. LeRoy, Qenesei county. Pig. 6. Front view of an internal east of a small cephalon, enlarged one diameter; showing the rotundit) of the glabella, the elevation of the occipital ring and the projection of the genal spines. Fig. 7. Profile of the sane-, showing the protuberant glabella and the elevation of the genal spines. Upper Helderberg lin North Cayuga, Provina of Ontario. Fig. 8. The internal surface of the cephalon, enlarged one diameter. Corniferous limestone. FalU of tin Ohio. Fig 9. An imperfect individual, retaining the cephalon and a portion of the thorax. Corniferous limestone. Canandaigua, Ontario county. Fie-, in. A cephalon, drawn from a gutta-percha impression of the dorsal surface, and slightly restored on one side ; showing the glabellar furrows, the broad and deep occipital furrow, ami the stout -' iial spines. Enlarged one diameter. Upper Helderberg limestone. North Cayuga, Province of Ontario. Pig. 11. A large and characteristic pygidium, drawn from a gutta-percha.impression of a natural mould of the dorsal surface. Fig. 12. The internal surface of the same specimen, showing the simple pleural annulations corresponding to the duplicate ribs of the upper surface. Upper Helderberg limestone. W&lpole, Provina if Ontario. 1' 13. A small, imperfect cephalon, showing the glabellar furrows. Upper Helderberg limestone. North Cayuga, Provinei of Ontario. Fig. 14. A. pygidium of. average size. Corniferous limestone. Liuu Rock, near LeRoy, Genesee county. Fig. 15. A portion of a small pygidium, enlarged, to three diameters; showing the paired muscular -ears, through the slightly weathered crust. Corniferous limestone. Canandaigua, Ontario county. Fig. 16. A huge cephalon. preserved as a cast of the internal surface, and showing the genal spines. • Oriskany sandstone. Cayuga, Provina of Ontario. Fig. 17. A pygidium, preserved as an internal east, and found in association with cephala similar to the foregoing. Oriskany sandstone. Cayuga, Provina of Ontario. This and the preceding Specimen are referred with some hesitation to this variety, and may more properly lie regarded as examples of the species itself. Fig. IS. An hypostoma, found in association with fragments of this variety ; enlarged to four diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. 21. Fig. 22. Fig. 23. Pig. 24. PLATE V1I1 A— Continued. Phacops Logani, Hall. Fig. 19. The type S] Lmen, figured in Palaeontology of New York, vol. iii, pi. 73, tig-. IT). [ntroduced for comparison with the Upper Helderberg species of Phacops. Fig. Jo. A cephalon of this species, enlarged one diameter, retaining normal proportions and showing the glabellar furrows and genal spines. Lower Helderberg group. Schoharie, Schoharie county. Phacops i;a\a. See Plates 6, 7, 8 and 25. A small individual, showing normal proportions ami a perfect dorsal surface. Hamilton group. Eighteen-mile Creek, Erie county. A larger ami unusually perfect, individual, showing the glabellar furrows on the dorsal surface. Hamilton group. Darieii, Genesee county. An individual retaining the crust in perfection, but not normally extended. Profile of the same. Hamilton group. In tin- drift at Ann Arbor, Michigan. Fig. 2n. An individual, compressed laterally, parallel to the cleavage'planes of the shales, a frequent mode of preservation. Fig. 26. Anterior view of the same. Hamilton group. Eighteen-mile Creek, Erie county. Pig. 27. A very small enrolled individual. Hamilton group. Eighteen-mile Creek, Erie county. Fig. 28. A still smaller, enrolled example. Hamilton group. Canandaigua Lol,t . Fig. 2'.i. The hypostoma of a large individual, retaining only a small portion of the crust. Hamilton group. Canandaigua Lake. Fig. 30. An internal east of the cephalic doublure and a portion of the thorax, enlarged one diameter to show the crenulations of the sub-frontal sulcus. Hamilton group. Fultonham, Schoharie county. Fig. 31. A portion of the thorax, enlarged one diameter j snowing the internal surface of the axial arches and their prolongation into the \ isceral supports or processes for the attachment of the ambu- latory muscular apparatus. Hamilton group. Canandaigua Lake. Fig. 32. A vertical section through an enrolled individual, cut near the axial furrow, and showing the projection of the ventral axial processes through the translucent calcite with which the interior space is filled. The specimen also shows a section of the hypostoma. indicating the'deep and abrupt deflection on it.- posterior margin. The drawing gives an enlargement to two diameters. Hamilton group. Canandaigua. Ontario county. Fig. :'.:'.. A section of an enrolled example, cut along the middle line of the axis, retaining only the thoracic portion, and showing three of the ventral processes. The light line parallel with the upper margin may represent the ventral membrane beneath the viscera. Hamilton group. Canandaigua, Ontario county. Bronteus Tullii is. Page 12. Fig. 34. The pygidium, natural size. Fig. 35. The same, enlarged to two diameters. Tully limestone. Kingsley's Hill, near Otisco, Onondaga comity. Pig. 36. The frontal doublure, probably belonging to the same species. Tully limestone. Uoroiliim, Onondaga county. I I'llM "I'm I ,x ki;d\ n 111. 1 Palaeontology of N Y VoML P mmons del PLATE IX. Dalmanites (Chasmops) anchiops. Page 59. See Plato 10. Fig. 1. A small cephalon, preserving: the normal proportions, but denuded of must of the crust. Schoharie grit. Schoharie, Schoharie county. Pig-. ■!. A cephalon of average size, a cast of the interior. Pig. 3. Profile view of the same specimen, showing the convexity of the glabella and the length ami direction of the occipital spine. Schoharie grit. Schoharie, Schoharie county. Fig-. 4. A small lint quite perfect cephalon. retaining the crust, showing the true proportions and the coalesced glabellar lobes. The specimen is enlarged to two diameters. Profile view of the same, showing the elevation of the occipital spine. The right eye of the same enlarged to three diameters. Schoharie grit. Schoharie county. 10. An imperfect cephalon, with unusually long genal spines ; referred with doubt to this species. Schoharie grit. Schoharie county. The thorax and pygidium. drawn from a gutta-percha impression of a natural mould. Schoharie grit. Schoharie, Schoharie county. The type of Dr. Green's description. This specimen is the only one yet observed retaining all the parts in juxtaposition, but the crust is for the most part wanting, and the occipital and caudal spines are broken away. Schoharie grit. Ulster county. Dalmanites (Chasmops) anchiops, var. armatus. Page 62. See Plate 10. Fig. 7. An imperfect cephalon, showing the long occipital spine. Schoharie grit. Schoharie county. Fig. S. A very large cephalon, slightly unsymmetrical, showing the occipital spine and the obtuse genal angles. Schoharie grit. Near Clarksville, Albany county. Pig-. 9. A fragment of the cephalon, showing the occipital spine. Schoharie grit. Schoharie, Schoharie county. Dalmanites (Chasmops) anohiops, var. sobrinus. Page 62. Pig. 11. A cephalon. showing the semicircular outline, convex glabella and obtuse genal extremities. Schoharie grit. Schoharie, Schoharie county. Fig. Fig. 6. Pig. 10. Fig. 12. Pig. L3. .'.aeontc. trm r ' m.^\ . f ■■*£^ * J J1 - »IIP 2 f **> \ PLATE X. Dalmanites (Chasmops) anchiops. See Plate 9. I.'j^r i. An imperfect eephalon. retaining a portion of the (■rust. Corniferous limestone. Falls of the Ohio. Fig'. 2. A. large pygidium, in the condition of an internal cast, from which the doublure and spine have I ii removed. This figure is from a plaster cast of Green's original of Aaaphus laticostatus. Schoharie grit. Ulster county. Fig. '.i. A small pygidium, retaining tl rust ami showing oblique rows of nodes on the pleurae. Fig. -1. The same, enlarged one diameter. Schoharie grit. Schoharie, Schoharie county. Fig. :">. A small pygidium, retaining the crust ami bearing an unusually long caudal spine. Schoharie grit. Schoharie, Schoharie county. Fig. 6. A larger pygidium. Schoharie grit. Schoharie, Schoharie county. Fig. 7. A pygidium, from which the tail-spipe has been broken. Oriskany sandstone. From tin ciciiiity of DeCewville, Province of Ontario. Fig. 8. A large pygidium. Fig. '.). Profile of the same, showing the curvature and elevation of the spine. Schoharie grit. Schoharie, Schoharie county. Fig. 10. A small pygidium, preserved as an internal cast, and showing the impression of the doublure ami spine. Schoharie grit. Knox, Albany fount;/. Fig. II. An enlargement to six diameters of the anterior extremity of the head represented on Plate 9, fig. 4, to show the crenulation of the frontal border. Fig. 12. A very large imperfect pygidium restored in outline. Schoharie grit Schoharie, Schoharie county. Fig. I:!. A targe, nearly entire pygidium, showing the tendency to duplication in the pleural annulations. Schoharie grit. Schoharie, Schoharie county. Dalmanites (Chasmops) anchiops, var. akmatus. See Plate 9. Fig. 1 1. A restoration in outline of the entire animal, from the eephalon figured on Plate 9, Fig. 8. ilsontologyo Brhohai n Oi II ( I • 1 1 \ i c . I ' 1 I i I- ) . PLATE XI. Dalmanites (Corycephalus) regalis. Page 65. ' Fig. 1. A. cephalon, showing' the general proportions, the character of the border and the length of the genal spines The eyes, a portion of the glabella, the occipital ring and part of the light anterior margin have boon destroyed by weathering. Fig. 2. Profile of the same, showing the elevation of the head, the abrupt anterior slope and the direction of the marginal denticulations. Fig. S. Front view of the same. Schoharie grit. Knox, Albany county. Fig. 4. An imperfect cepbalon, showing the eyes and the glabellar lobes. Schoharie grit. Knox, Albany county. Dalmanites (Corycephalus) pygm.eus. Page 56. Pig. .r>. An imperfect cephalon, drawn in outline, natural size. Fig. B. The same, enlarged to ten diameters, showing the denticulate character of the frontal margin, the elongate glabella and narrow glabellar lobes. Corniferous limestone. Canandaigua, Ontario county. Fig. 7. Another head of this species, natural size. Fig. S. The same, enlarged to ten diameters, showing the position of the eye, the denticulate lateral border, and the long- cheek-spine. Corniferous limestone. Canandaigua, Ontario county. I 'I'M. I PLATE XI a. Dalmanites v' I ausmannia) pleuroptyx. Page 28. Fig. 1. A cephalon of average size, showing the general proportions, the crenulations on the frontal border and the peculiar ornamentation of the cheeks. The left eye and a portion of the left cheek spine are restored in the drawing. Lower Helderberg group. Near Clarksv, ly county. Pig. 'J. A cast of the under side of a pygidium regarded as belonging to this apei Oriskanj sandstone. Cayuga, Provinci of Ontario. Fig. 3. A pygidium retaining must of the crust, and showing the normal charactei-a of the species. Comiferous limestone. Lime Hock, Genesei county. Dalmanites (< Iorycephalus) dentatus. Page 58. Fig. 4. A somewhat imperfect individual, but the most complete yet found, and the only one observed in which the parts of the body are retained in conjunction. Lower Helderberg group. Port Jervis, Orange county. Fig. y. A cephalon, nearly entire, showing the characteristic marginal ornamentation. Lower Helderberg group. Port Jervis, Orange count;/. Fi«. 6. A pygidium, somewhat more flattened than that in fig. 4; showing the character of the surface ornamentation and the bifurcate pleural ambulations. Lower Helderberg group. Port Jervis, Orange county. D.U.MAMIES (COUONI IIA '?) EMARGINATUS. Page 40. Fig. 7. A fragment of a pygidium, enlarged to two diameters, showing the broadly emarginate posterior extremity, and the bifurcate, regularly tubercled ribs. Schoharie grit. Schoharie, Schoharie county. Fig. 8. Another imperfect pygidium. natural size, showing similar characters. Schoharie grit. Scholiarie, Schoharie county. These two are the only specimens of this species observed. Dalmanites (Hausmannia) concinnus. Page il). Pig. 9. A small pygidium, enlarged to two diameters. Schoharie grit. Schoharie, Schoharie county. Fig. 10. A larger pygidium, also enlarged to two diameters, showing the broad, flat angulations and the conspicuous posterior border. Pig; 11. A profile of the same, similarly enlarged. Schoharie grit. Schoharie, Schoharie county. Dalmanites (Hausmannia) concinnus. var. serrula. Page 30. Fig. 12. A very small pygidium, enlarged to three diameters. The specimen, in addition to the normal characters of 1). com innus, has a row of spinules on the lateral margins. Upper Helderberg group. North Cayuga, Province of Ontario. Dalmanites (Coronl'ua) myrmecofhorus. See Plates 13, 14, and 15. Fig. 13. A large glabella, referred with doubt lathis species. Comiferous limestone. Schohar'u \. '), Schoharu county. PLATE M A.— Coiuiuucil. Dalmanites (Chasmops) macrops. Page 68, Fig-. 14. An imperfect cephalon, showing the .character of the glabella, the coalesced lateral lol.es. and the verj prominent eye. This is the type specimen. Fig. ir>. Profile view of the same, showing the size and elevation of the eye. Corniferous limestone. Schoharie, Schoharie county. Dalmanites (Chasmops?) Eiuna l'a,i;o 67. Fig. 16. A pygidium preserving symmetry of funn and showing the flat annulations and broad bqrder. Fig. 17. Profile view of the same. Corniferous limestone. Clarenct Hollow, ErU county. Fig. is. A larger pygidium, somewhat unsymmetrica] in outline on account of the unequal width of the border. Corniferous limestone. Fmui a boulder in tin toirii of Naples, Ontario county. Dalmanites (Chasmops) Calypso. Page 64. Fig. 11'. An entire individual, drawn from a gutta-percha impression of a natural mould of (lie dorsal sur- face; showing the general form and proportions, the coalesced glabellar lobes, the relatively large eyes, and the axial row of flattened spines on the pygidium. Fig. 20. Profile of the same showing the elevation of the body and the height of tin- pygidial spines'. Fig. 21. An hy post oma found in place with the foregoing speci n, somewhat imperfect on its posterior extremity, but showing its general character. Corniferous limestone. Sandusky, SanoVusky county, Ohio. fig. 22. An imperfect pygidium, the type of the species. The drawing does not show the characteristic angularity of the axis. i irniferous limestone. Falls of the Ohio. Dalmanites (Hatjsmannia) piiacopty.x. l'age 31. Fig. •-•:;. A fragment of a pygidium, natural size, showing the prominent caudal ridge ami spine, and the acute tubercles ami spinules covering the surface. The drawing is made from a guttapercha impression of a natural mould of the dorsal surface. Fig. 24. Pii file of the same specimen, with the caudal spine drawn in its normal position, and showing- the conspicuous spinules upon the annulations. Upper Helderberg limestone. North Cayuga, Provinei of Ontario. Pig. 25. A portion of the right side of a pygidium, drawn from a cast of the lower surface of the tost. Upper Helderberg limestone. North Cayuga, Provinei of Ontario. Fig. 26. A portion of the loft side of a pygidium, showing the normal curvature ami the bifurcate character of the annulations. Upper Helderberg limestone. North Cayuga, Province of Ontario. Fig. 'J7. A large hypostoma found m association with the pygidia of this species. Upper Helderberg limestone. North Cayuga, Province of Ontario. Dalmanites (Hausmannia) Meeki. Page 32. Fig, 28. The glabella, showing the . of its lobation. Fig. -'.'. Dorsal view of a pygidium, showing the number of annulations and character of the caudal spine. Fig'. 30. Profile view of the same specimen, showing the elevation of the caudal spine. Tin- above illustrations are from the type specimens of the species. Lower Devonian limesf ■■ Eureka District, Nevada. I Hil.M't il*Jll.> I Paleontology of NYVoML PLATE XI i.. DALMANITES (OdONTOOEPHALUS) . Kc;ki;i \. Page Fie. 1. The cephalon. A. cast of the internal surface from which the eyes have been broken; showing the eleven denticiilations on the frontal margin and the long, slender genal s] Fig. 2. Profile of the sane-. Opper Helderberg limestone. Williamsville, Eru county. Fig. 3. A nearly . -n t "n-.- individual, enlarged to two diameters, showing the distinguishing features of the species. The pygidium has ' n drawn too narrow and constricted near the posterior extrem- ity, and the caudal spines too I Fig. 4. Profile of the same. Corniferous limestone. Chittenango, Madison county. Fig. 5. Dorsal view of the frontal cephalic border, enlarged to two diameters, showing the shape and number of the denticulations. Upper Helderberg limestone Williamsville, Brit county. Fig. 6. Lower surface of the frontal doublure, enlarged to two diameters, showing the incisor-like form of the denticulations and the openings of the vertical tubuli pores. Upper Helderberg limestone. Williamsmlle, Erie county. Fig. 7. A pygidium, showing unusually long terminal spines. Upper Helderberg limestone. Williamsville, Erie county. Fig. 8. A smaller pygidium. Fig. 9. Profile view of the same. Upper Helderberg limestone. Williamsville, Eru county. Fig. 10. A pygidium of average size, showing normal i roportions. Upper Helderberg limestone. Schultz's Farm, near Clarence, Eru county. Fig. 11. The axis of the pygidium. drawn from an internal cast, to show the median depression and obso- lescem ; of the an n illations near ttie extremity. Enlarged to two diameters. Upper Helderberg limestone. Schultz's Farm, near Clarence, Erie county. I >AI.MANITKS (( )im ixit (CEPHALUS ''.) CORONATUS. Page I Fig. 12. The pygidium and a portion of the thorax. The specimen shows the characteristic broadlj emar- ginate, aspinose posterior extremity, and a somewhat shorter pygidium than in the associated species. Corniferous limestone. Near Aubm , Cayuga county. Fig. 13. The pygidium of the same specimen, introduced for comparison with the adjoining pygidia. Fig. 14. An imperfect pygidium, referred with doubt to this species. Corniferous limestone. Schoharie, Schoharii county. Dalmanites (Odontooephalus) selenurus. Page 49. See Plate 12. Fig. 15. A pygidium preserving normal proportions and showing the divergent, slender terminal spines. One side of the figure is somewhat restored. Corniferous limestone. Schoharie, Schoharii county. Fig. 16. A small pygidium having more nearly parallel spines ; drawn from a east of the internal surface. Fig. 17. The same, viewed in profile, showing- the ele\ atii n of the terminal spines. Corniferous limestone. C(tn. Profile of the same, showing the elevation of the eye. Corniferous limestone. Canandaigua, Ontario county. Fig. 7. A cephalon, an impression of the interior, showing the casts of tubulipores on the anterior margin. Enlarged to two diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. S. Anterior view of a large, enrolled individual retaining a portion of the crust. Fig. 9. Posterior view of the same, the pygidium truncated by the breaking away of the caudal spines. Corniferous limestone. Schoharie, Schoharie county. Fig. HI. A small, enrolled individual from which the crust has been broken away. Fig. 11. Profile view of the same. The left eye of this specimen has been restored in the drawing. Corniferous limestone. Schoharie, Schoharie county. Fig. ['2. A portion of the cephalic border, enlarged to three diameters, showing the shape of the denticu- lations and their strongly granulose anterior edges. < 'orniferous limestone. Lime Rock, near LeRoy, Genesee county. Fig. \?>. A block of decomposed chert, bearing two nearly entire individuals and portions of several others, all preserved as infernal casts. Corniferous limestone. From a loose boulder five miles smith of Ovid, Seneca county. ( PHAIClI'l I \ ^ 9 PLATE XIII. Du.MANITES (CORONURA) ASPECTANS. Page 33. 1. A fragment of the cephalon, showing' the left cheek, the eye and a portion of the glabella. Corniferous limestone. Columbus, Ohio. Fi°\ 2. The left movable cheek, with the visual surface of the eye attached, showing the great elevation of this organ. This specimen is the original of Conrad's description. Corniferous limestone. Near Schoharie, Schoharie county. l iecimen, showing the eye. Fig. 4. A portion of the visual surface of the last specimen, enlarged to six diameters. rniferous limestone. Schoharie, Schoharie county. Fig. ">. The pygidium of a small individual, showing the character of the surface ornamentation. The marginal spines and the posterior portion of the shield have been lost, and are restored in outline. .is limestone. Columbus, Ohio. Pig. 6. A small pygidium. showing pathological deformity. is limestone. Columbus, Ohio. Pig. 7. A pygidium from which the surface and marginal ornamentation has been worn away. This in. 'ii originally used in the description of Dalmanites Helena, Hall. Corniferous limestone. Columbus, Ohio. Fig. 8. A pygidium of average size retaining the marginal spines. The drawing is made from a gutta- percha impression from a natural mould of the dorsal surface, and the tubercles of the sur- face ate obsolete. Corniferous limestone. Columbus, Ohio. 9. An entire pygidium, showing the normal length of the marginal spines. The surface ornamenta- solete. Corniferous limestone. Lirru Rock, war LeRoy, Genesee county. Fig. Id. A large and somewhat impei-fect pygidium, showing the characteristic ornamentation of the crust. Corniferous limestone. Columbus, Ohio. Pig. 11. A large pygidium, retaining portions of the marginal spines, and scattered tubercles over the surface. Corniferous limestone. Columbus, Ohio. Pig. 13. A fragment showing the terminal portion of a pygidium which is referred with some hesitation to this speeies. i'lie sirt.'oe ornamentation is similar to that in D. aspectans, and the marginal spines have been broken away, with the exception of the final pair which are unusually large. This form is believed to be identical with Mr. Conrad's Asaphus? denticulatus. ■niferous limestone. Schoharie, Schoharie county. Dalmanites (Coronuua) myrmecophorus. l'agc 37. See Plates 11 a. 14 and 15. 12. The pygidium of a small individual, which shows a certain degree of similarity with that of /;. aspectans in the so what regular arrangement of the surface tubercles. The specimen shows, however, the base of tin- strong terminal axial spine characteristic of D myrmecophorus. Corniferous limestone. /,/,„, Rock, near LeRoy, Genesee county. I ( PHACOPID.fi I i * PLATE XIV. DALMANITES (COEONURA) MY11MECOPHORUS. Page 37. See Plates 11a. 13 and 15. Fig-. 1. An unusually perfect pygidium of about average size, showing the general convexity, the irregu- larly scattered nodes, and some of the marginal spines. The second spine on the right margin of the shield was apparently broken off ami healed during the life of the animal. Fig. la. A transverse section in outline near the anterior margin, to show the convexity of the axis and pleurae, and the upward direction of the spines. Corniferous limestone. City Hall quarry, Kingston, Ulster county. Fig. -. A fragment of the pygidium of a very large individual. Corniferous limestone. Schoharie, Schoharie county. Fig. 3. A fragment of a smaller pygidium, showing the length and curvature of the marginal spines. Corniferous limestone. Schoharie, Schoharie county. Fig. 4. A fragment, showing the terminal portion of the pygidium. This figure is from the original of Mr. Conrad's Asaphusf acantholeurus. The drawing does not make the base of the central spine sufficiently large. Fig. 5. A side view of a gutta-percha impression made from the counterpart of the foregoing specimen, showing the length of the spines on the posterior border. The central spine is normally bifid, but this character is not perfectly retained in the impression. Fig. 6. The same viewed from the front. Corniferous limestone. " Near Schoharie, in limestone with Odontocephallis {Onondaga limestone) " (Conrad). kpipies. :keldl ( PHACOPID.-E ) alaon- . ■.nmons del PLATE XV. DALMANITES (CORONURA) MYRMECOPHORUS. See Plates 11 a, 13 and 14. Fig. 1. A very large pygidium, natural size, accompanied by a restoration in outline of the other parts of the animal, to indicate its probable proportions when entire. This restoration is made from data supplied by fragmentary remains of the cephalon and thorax, and from careful comparison of the relative proportions of the different parts in entire individuals of various species of Dahnanites. Corniferous limestone. Near Clarksvttle, Albany county. Fig. 2. A profile of the terminal portion of the same specimen more carefully prepared, showing the con- tinuation of the axis to the posterior border, and the elevated, spinose character of the latter. Fig. 3. An outline profile of one-half the posterior border viewed from behind, showing the bifid central spine. Fig. 4. Restoration from a fragment of the smallest individual observed; natural size. Comiferous limestone. Canmulaigua, Ontario county. PLATE XVI. Dalmanites (Cryph^ius) Boothi. Page 42. Plate 16 \. 1. Am entire individual, of about average adult proportions, showing the short an. I broad genal spines, anodose axis and d :audal fimbi Pig. 2. Profile of the same, showing 'In' broad, blunt and laterally flatte I genal i Hamilton group. Canandaigua Lake. ;!. A small cephalon, pr< orrnal prop the genal spines 1 ored Hamilton group. Canandaigua Lake. Pig. 4. A fragmentai-y specimen, showing the usual characters of thorax and pygidium. Hamilton group. Canandaigua Lake. Dalmanites (Cinrii.i.us) Boothi, var. Calliteles Page 1 5 See Plate 16 a. Fiy. 5. A very young individual, drawn in outline and partially restored. This is the earliest stage of growth noticed, and an enlargement of the pygidium is given on plate 16 x. fig. 12. Hamilton group. Canandaigua, Ontario county. 6. An individual in a later stage of development, partially restored. An enlargement of the pygi- dium is given on plate 16 A, fiir. 13. Hamilton group. Canianaaigua, 0 7. An individual in a more advai I stage oi growth than the pr ling, partiallj restored, in enlargement of the pygidium is given on plate 16 A, fig. 14. Hamilton group. Canandaigua, Ontario county. Fig. 8. A still larger individual, slightly incurved, and thus made to appear broader than normal. Hamilton group. Canandaigua, Ontario county. big. 9. A slight! j larger individual, also somewhat enfolded. This example preserves the axial row of nodes, and rounded, but pustulose caudal spines. The genal spines, however, are like those of the sp' thi rather than those1 of the variety Calliteles, and the specimen represents a form intermediate between normal examples of the species ami its varietj Hamilton group. Canandaigua Lake. Pig. in. An individual in a la gr iwth, showing the long, slender caudal spines. Hamilton group. Canandaigua. Ontario county. Pig. 11. An individual, somewhat below the normal adult size, but showing all tin- characteristic: of the variety. Fig. 12. Profile of the same, showing the long, acute genal spines. Hamilton group. Canandaigua, Ontario 'county. Fig. 13. A normal individual, of average size. Hamilton group. Canandaigua, Ontario county. Fig. 14. The individual represented in fig. 9. Enlarged to two diameters. I.">. The same in profile, showing the character of the genal spines Pig. 16. A very large cephalon. Hamilton group. Canandaigua Lake. Big. 17. A thorax and pygidium, of unusually large size. Hamilton group. Canandaigua L< Fig. 18. An enrolled individual, showing the caudal fimbria projecting beyond tin' frontal border. Hamilton group. Near LeRoy, ffeneset county. Fig. 19. Anterior view of a smaller, partially enrolled individual. Fig. lid. Lateral view of the same. PLATE XVI— Continued. Fie. 21. Posterior view of the same, showing' the projection of the genal spines beyond the thorax. Hamilton group. Canandaigua. Ontario county. Fit;-. 22. A block of shale, shoving- a group of trilobites, including DalinanUes (C'ryplmiis) BootM, var. Calliteles, Phacops rana and Oyphaspis craspedota. In Hie upper left-hand individual, the right genal spine has been broken and healed before fossilization A little to the right of the center of the block is shown the hypostoma of Dalmanites (Orypliwus) Boothi, var. Calliteles. Hamilton group. Canandaigua, Ontario enmity. I HH \i nl'lll I ) -vofNY;. ■ : ilUlllth. PLATE XVI a. Dalmanites (Cuypii.kus) COMIS. Page 41. Fig. 1. The internal easi of a pygidium, enlarged to three diameters, and considerably restored. Upper Helderberg limestone. Cayuga, Province of Ontario. Dalmanites - (Cryph^eus) Pleion e. Page 41. Kif,r. 2. View of the type specimen. Corniferous limestone. Falls of the Ohio. Dalmanites (Cryph.eus) Boothi. See Plate 16. Fig. 3. A small pygidium, showing the flattened marginal spines. Hamilton group. Darien, Genesee county. Fig. 4. A larger pygidium, in which the marginal spines are longer and gently rounded, and the terminal spine acute. Hamilton group. Canandaigua Lake. Fig. 5. The internal surface of a pygidium. in which the spines are broad and flat. Hamilton group. Near Geneseo, Livingston county. Fig. 6. Similar view of a smaller pygidium. with more elongate spines. Hamilton group. Near Geneseo, Livingston county. Fig. 7. A large pygidium, with spines of the normal character. Hamilton group. Canandaigua Lake. Fijf • 8. Three of the marginal spines of the specimen represented on plate 1 6, fig, 1, enlarged to three diameters. Dalmanites (Ckyph.eus) Boothi, vjir. Calliteles. See Plate 16. Fig. 9. An imperfect pygidium, referred with some hesitancy to this variety. The long, acute spines are different from those in the normal adult forms of either the species or the variety. No cephala accompanying such pygidia in the Hamilton shales have been observed. Hamilton group. Jay cox's Run, Livingston county. Fig. 10. A pygidium with similar characters. The associated cephala bear the diagnostic characters of this variety. Tully limestone. Goodwin's, Cayuga Lake. Fig. 11. A normal adult pygidium, enlarged to two diameters, showing the elevated, lanceolate marginal spines. Hamilton group. Canandaigua, Ontario county. Fig. 12. The pygidium of the youngest individual observed (plate 16. tig. 5). enlarged to twelve diameters, showing the incurvature of the axis ; the long, terete marginal spines, diminishing in length posteriorly, and the undeveloped terminal spine. Hamilton group. Canandaigua, Ontario county. Fig. 13. An individual in a slightly advanced stage of growth (plate 16, tig. 6), enlarged to ten diameters, showing an approximation in the relative length of the spines. Hamilton group. Canandaigua, Ontario county. Fig. 14. An individual in a later stage of growth (plate 16, tig. 7), enlarged to nine diameters, showing the approximately equal length of the spines, except in the last pair, and the increasing size of the terminal spine. PLATE XVI A— Continued. Hamilton group, Canandaigica, Ontario county. Fig. LP. An individual in a still later, immature stage of growth, enlarged to seven diameters. Hamilton group. Hopewell, Ontario county. Pig. 16. A fragment representing the largest pygidium observed. Hamilton group. CiinaudaUjim Lake. Fig. IT. Four marginal spines of a pygidium, similar to the one represented iti tig. 9. Enlarged to three diameters. Dalmaxites (CkyI'H.EUs) Barrisi. Page 4s. Fig. Is \ ]'\ l;- i < 1 i mil. enlarged to three diameter's, and showing the round, terete marginal spines, and the conspicuous terminal spine. Hamilton group. Davetuport, Iowa. I I'll M ( ll'U) I I Jaeontolooy:.: NYYoIVri. r " • r _J PLATE XVI b. ACIDASPIS CALLICERA. Page 89. Fig'. 1. An imperfect specimen, natural size, retaining the head and six thoracic segments. Fig. '_'. The same, enlarged to two diameters. Corniferous limestone. Camillus, Onondaga county. Fig. 3. A larger, more nearly entire individual, drawn to two diameters. The specimen is an internal cast in decomposed chert, and has the cephalon somewhat deflected. Fig. 4. Profile of the same, similarly enlarged. Fig. 5. An anterior view of the same, showing the elevation of the glabella and eye-lobes. Fig. 6. The natural mould of the dorsal surface of the same specimen, similarly enlarged. Fig. 7. A gutta-percha impression from this mould, showing the ornamentation of the surface. Upper Helderberg limestone. Cayuga, Province of Ontario. Fig. 8. The glabellar portion of a small cephalon, enlarged to two diameters. Upper Helderberg limestone. Cayuga. Province of Ontario. Fig. 9. The left movable cheek, showing the length of the marginal and genal spines. Enlarged to four diameters. Corniferous limestone. Canandaig ita, Ontario county. Fig. 10. The glabellar portion of a head, enlarged to two diameters, showing the denticulations on the frontal margin. Upper Helderberg limestone. Cayuga, Province of Ontario. Figs. 11 and 12. Right and left movable cheeks, drawn from internal casts, and showing the number of marginal spines. Upper Helderberg limestone. Cayuga, Province of Ontario. Fig. 13. Lateral view of a left movable, cheek, retaining the eye. Enlarged to two diameters. Schoharie grit. Near Clarksville, Albany county. ACIDASPIS, Sp. Page 71. Fig. 14. An imperfect pygidium, enlarged to two diameters. Upper Helderberg limestone. Cayuga, Province of Ontario. ACIDASPIS ROMINGEKI. Page 71. Fig. 15. A fragmentary pygidium, restored in outline to show the great length of the marginal spines. Enlarged to two diameters. Fig. 16. The same in profile. Fig. 17. A portion of the anterior marginal spine of the same specimen, to show the character of the ornamentation. Enlarged to six diameters. Fig. 18. A similar enlargement of the terminal portion of the fourth marginal spine. Hamilton group. Little Traverse Bay, Michigan. 1 1 , eomologyofNY?, 14- PLATE XVII. Lichas (Terataspis) gkandis. Page 73. See Plates 18 and 19. Fig. 1. Profile of the cephalon represented on plate 18, showing- the elevation of the glabella and one of the glabellar spines; the occipital ring, and the constriction about the base of the frontal lobe. Upper Helderberg limestone. Cayuga, Prouim t of Ontario. Fig. 2. Dorsal view of a much w< athered specimen of the cephalon, wanting the free cheeks. Fig. 3. Profile of the same. Schoharie grit. Schoharie, Schoharie county. Fig. 4. Tho posterior portion of a large cephalon, showing the prominent lateral lobes and bases of the double glabellar spines, and the broad occipital ring with the clavate processes upon its posterior margin. The base of a strong spine lying just within the palpebral furrow, which is shown in the specimen, is not represented in the figure. Fig. 5. The same viewed from behind, showing tin- elevation of the lateral lobes and of the processes upon the occipital ring. Schoharie grit. Schoharie, Schoharie county. Pig. 6. An imperfect pygidium, showing the pleural annulations and a portion of the marginal spines. Schoharie grit. Schoharie, county. I I.T4 HA1I.K -^ ! ^ ll ft ■ 4 PLATE XVIII. Lichas (Tehataspis) GKANDIS. See Plates 17 and 19. Fig. I. Dorsal view of a very large cephalon wanting' the movable cheeks, showing the double spines on the lateral lobes, and the very broad occipital ring, with the clavate processes upon the posterior margin restored in outline. The specimen shows the base of a strong spine situated just within the palpebral furrow, but this is not represented in the drawing. Fig. '_'. Tin- same viewed from behind, showing the elevatiou of the frontal and lateral lobes. Upper Helderberg group. Cayuga, Province of Ontario. ( LICHAD.fi.) .yofNYyoMI. Plate s - PLATE XIX. Lichas (Teeataspis) qrandis. See Plates 17 and 18. Fig. I. A fragment of tin- pygidium, retaining one "f the terminal spines and ;i portion of the other. showing the size and distribution of the spinules upon their surface. The drawing is made from a gutta-percha impression of the dorsal surface. Schoharie grit. Near Clarksville, Albany county. Fig. 'J. An imperfect pygidium, retaining a portion of the crust, and showing the character of the axis and post-axial area. Schoharie grit. Schoharie, Schoharie county. Fig. :i. An imperfect pygidium of average size, showing the internal surface and retaining portions of the spines, the missing parts being restored in outline. This specimen is in the "Ward Museum of Rochester University. Schoharie grit. Schoharie, Schoharie county. Fig. 4. A very small pygidium, in which the axis and lateral annulations extend to the margin. Referred with some doubt to this species. Schoharie grit. Near Clarksville, Albany county. Fig. 5. The frontal lobe of a small individual, with a portion of the cheek attached. Schoharie grit. Schoharie, Schoharie county. Fig. i''. The axial arch of a large thoracic segment, showing the strong divergent spines. The figure is drawn from a gutta-percha impression from a natural mould of the dorsal surface. Schoharie grit. Knox, Albany county. Fig. 7. A thoracic segment of a smaller individual, drawn in profile, showing the axial spines. Schoharie grit. Near Thompson's Lake, Albany county. Lichas (Conolichas) pustulosus. Page 80. Fig. S. A pygidium, retaining a portion of the crust, showing the broad, doublure, the two pairs of lateral spines and the conspicuous terminal lobe. Lower Helderberg group. Near Clarksville, Albany county. Fig. lo. The left free cheek of a large example. Lower Helderberg group. Schoharie, Schoharie county. Fig. 1 1. The right free cheek of an individual of about the same size as the preceding. Lower Helderberg group. Schoharie, Schoharie county. Lichas (Conolichas ?), sp. '1 Page 80. Fig. 9. A pygidium, showing the internal surface, three pairs of lateral lobes and a relatively narrow terminal lobe. This specimen was incorrectly figured in Paleontology of New York, vol. iii, pi. 78, tig. 7, and was there referred to Lichas pustulosus. Lower Helderberg group. Schoharie, Schoharie county. ■ Palaontologyof N ■>i. I d i PLATE XIX a. LlCHAS (CONOLICHAS) BlGSBYI (?). Page 80. Fig. I. A very large pygidium, drawn from a gutta-percha mould of the internal surface. One of the terminal spines in the specimen has been broken. This form of pygidium was formerly refer- red to the species Liehas pustulosus; but as the cephalon of that species is now known to have been accompanied by the form of pygidium represented on plate 19, fig. 8, this is referred with some hesitation to the species Liehas Bigsbyi, Hall. Lower Helderberg group. Schoharie, Schoharie count//. LlCHAS (CONOLICHAS) ErIOPIS. Page 78. Fig, 2. The intra-sutural portion of a cephalon, natural size, retaining the right palpebrum and a portion of the crust. Fig. 3. The same, enlarged to two diameters. Fig. 4. The same, viewed from the front, showing the comparative elevation of the glabellar lobes. Simi- larly enlarged. Fig. 5. The same, viewed in profile. Similarly enlarged. Corniferous limestone. Schoharie, Schoharie county. Fig. ti. A fragment of a smaller cephalon, enlarged to two diameters. Corniferous limestone. Schoharie, Schoharie county. Fig. 7. The right movable cheek, enlarged to two diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. S. Another specimen of the right cheek, somewhat distorted ; enlarged to two diameters. This and the preceding figures are drawn from gutta-percha casts of natural moulds in decomposed chert. Corniferous limestone. Canandaigua, Ontario county. Fig. it. A pygidium, showing the general proportions and the broken bases of the axial and pleural spines. Enlarged to two diameters. The marginal spines have been drawn with disproportionate lengths, the first pair being much too short, the second ami third pairs not long enough and the terminal pair too long. For the cor- rect representation of these spines, see fig. 15. Corniferous limestone. Schoharie, Schoharie county. Fig. 10. An imperfect pygidium, natural size. Corniferous limestone. Schoharie, Schoharie county. Fig. 11. An imperfect pygidium, showing the internal surface. Corniferous limestone. Schoharie, Schoharie county. Pig. 12. A fragment of a very large pygidium . Upper Helderberg limestone. Williamsville, Erie county. Pit,'. 13. A pygidium, showing the axial spine, and the length of the pleural and marginal spines. The original is an internal cast in decomposed chert. Enlarged to two diameters. Fig. 15. A restoration of the pygidium. drawn from the preceding specimen, showing the normal character of the axial, pleural ami marginal spines. Fig. 16. Profile view of the same, showing the leugth of the axial spine. Corniferous limestone. Canandaigua, Ontario county. LlCHAS (CONOLICHAS) HISPIDUS. Page 77. Pig. 14. A pygidium, natural size, showing the aspinose surface and the short marginal spines. Fig. 17. The same, enlarged to two diameters. The larger tubercles upon the pleural annulations do not represent the bases of spines. Schoharie grit. Schoharie, Schoharie county. Fig. 18. An imperfect pygidium, natural size, drawn from a cast in decomposed chert. Corniferous limestone. LeRoy, ffenesce county. I i.i i'ii.mi.i: .1 Palaeontology of NYyoIVIL i ; Plat. rrr iwer 1 ■■■ e w% v I -: 7) '.■•'-."'■ - PLATE XIX b. LlCHAS (HOPLOLICHAS) in I. I 1 8. Page SI. See Plate 25. Fig. 1. An imperfect eephalon. wanting the movable cheeks and the occipital ring, but showing the char- acter of the glabellar lobes. Fig. 2. Profile of the same, showing the elevation of the frontal and lateral glabellar lobes. Upper Helderberg limestone. Pmrinii of Ontario. Lichas (Arges) contusus. Page 83. Fig. 3. A eephalon, wanting the movable cheeks; showing the elongate frontal lube, the short and broad lateral lobes, and the relatively broad genal areas. The original is a cast of the internal surface, which makes the cephalic furrows appear broader and deeper than when the crust is retained. Enlarged to two diameters. Corniferous limestone. Canandoiyua. Ontario county. Fig. 4. A eephalon, wanting the movable cheeks, but retaining a portion of the crust. Fig. 5 The same, enlarged to two diameters. Fig. 6. The same in profile, enlarged to two diameters, showing the regular convexity of the frontal lobe, its elevation above the lateral lobes for its entire length, the convexity of the genal area, and the elevation of the occipital ring. Corniferous limestone. Near ClarJciVille, Albany county. Lichas (Ceratolichas) gryps. Page W. Pig, 7. The intra-sutural portion of a eephalon, retaining the crust and showing the gently undulate frontal border, the short, abruptly elevated frontal lobe, the depressed lateral lobes, and also the bases of two spines on the frontal lobe : of one spine on each cheek just within the eye- node, and a single long recurved and slightly incurved spine on the occipital ring, accompanied by the base of a second, the latter spine being restored in outline. Enlarged to two diameters. Fig. 8. A profile of the same similarly enlarged, the broken spines being restored in outline. Corniferous limestone. Schoharie. Schoharie county. Fig. 9. A small eephalon, showing the bases of the three pairs of spines. The specimen is inclined forward somewhat more than in the drawing of tig. 7, foreshortening the frontal lobe. The original is an internal cast in decomposed chert. Enlarged to three diameters. Fig. 10. The same, in profile. Fig. 1 1 . The same, viewed from the front. Corniferous limestone. Canandaigua, Ontario county. Fig. 12. A fragment of the middle lobe of the glabella, showing the length and character of its spines. Fig. 12a. The same, enlarged to two diameters. Fig. 13. The same, similarly enlarged and viewed in profile, showing the length and curvature of the gla- bellar spines. Corniferous limestone. Ciiiiiimloiyua. Ontario minify. PLATE XIX E— Continued. Lichas (Ceratolichas) DRACON. Page 85. Fig. 14. An imperfect eephalon, showing the transverse frontal margin, the short frontal glabellar lobe, the four spine-bases on the posterior extremity of this lobe and the spine-bas^s near the eye- nodes. Fig. 15. A profile view of the same, the outline of the eephalon being restored, and showing in restoration the probable length of the four pairs of spines. Corniferous limestone. Schoharie, Schoharie anility. Fig. 16. A portion of the frontal lobe of the glabella enlarged to two diameters; showing part of one spine of the outer pair, tin- bases of the other one and of the inner pair. Fig. 17. The same, in profile. Corniferous limestone. Schoharie, Schoharie county. Fig. IS. A very small glabella, retaining the inner pair of spines and portions of the others. Fig. 18b. The same enlarged to three diameters. Corniferous limestone. LeRoy, Genesee county. LlCHAS (I)ICRANOGMUS) PTYONUKL'S. Page S6. Fig, 19. The intra-sntural portion pfithe eephalon, enlarged to two diameters ; showing the form and character of the glabellar Lojbes and furrows. Niagara group (Coralline limestone). Schoharie, Schoharie county. Fig. 20. A pygidium, apepmpanied !>>' the last thoracic segment, enlarged to two diameters. Niagara group (Coralline limestone). Schoharie, Schoharie county. Fig. '-'I. A smaller but more perfect pygidium, enlarged to two diameters, preserving the margin entire, and showing the number and character of the marginal spines. Niagara group (Coralline limestone). Schoharie, Schoharie county. i i.i < n. \ daeontologyofNYYo] 12a 18! 19 20 PLATE XX. PfiOETUS ^NGUSTIFRONS. 1'age 91. See Plate 22. Fig. 1. A portion of the cephalon, showing the glabella. The crust is mostly broken away, and the base of the glabella is made too wide in the drawing. Schoharie grit. Albany eourity. Pig. 2. The pygidium. The drawing fails to represent the faint grooves on the pleural annula.tions. Schoharie grit. Albany county. Fig. 3. Profile view of a .-mailer pygidium, enlarged to two diameters. Schoharie grit. Albany county. Fig. 4. A small pygidium, showing a slight emargination at the posterior extremity. Enlarged to two diameters. Fig. 5. Profile view of the same. Schoharie grit. Albany county. Proetus Conradi. Page 89. See Plates 21 and 22. Fig. 9. A pygidium of average size retaining the crust, and enlarged to two diameters. The pleural ampliations are rarely so distinct as in this figure. Schoharie grit. Albany county. PkOETUS CANALICULAR S. Page 107. See Plate 23. Fig. 10. The glabella and fixed cheeks enlarged to two diameters. The faint first pair of glabellar fur- rows is not represented in the drawing. Fig. 11. Profile view of the same. Corniferous limestone. Falls of the Ohio. Proetds CLAUUS. Page 104. See Plate 22. Fig. 12. A nearly entire individual, natural size. Fig. 13. Profile view of the same. Corniferous limestone. Stafford, Gftnesee county. Fig. 14. A small individual, showing a somewhat broader border and longer cheek-spines. Enlarged to two diameters. Corniferous limestone. Stafford, Genesee comity. Proetus Hesione. Page 93. Fig. 15. The pygidium on which this species was established, showing the greater length and more nu- merous ampliations than in associated species. Fig- 16. Profile view of the same. Schoharie grit. Schoharie, Schoharie county. PLATE XX— Continued. Cyphaspis minuscula. Page 140. See Plate 24. Fig. 17. An entire individual, enlarged to three diameters'. The outline of the pygidium is incoiTectly represented, and through an oversight has been left untinted. The cheek spines are also made to appear shorter than in the specimen. Corniferous limestone. Schoharie, Schoharie county. Proetus Vebneuili. Page 108. Fig. 18. The original specimen, showing a portion of the thorax, the pygidium, and the characteristic nodes on the pygidial border. Enlarged to three diameters. Fig. 19. Profile view of the same. Upper Helderberg limestone. Williamsville, Erie county. Proetus crassimarginatus. Page 99. See Plates 22 and 25. Fig. 6. The pygidium as a cast of the internal surface, showing the doublure and the obscure annulat ions. This usual condition of preservation in the Schoharie grit. Schoharie grit. Near Qlarksville, Albany county. Fig. 7. Profile view of a larger pygidium, an internal cast, upon which the ambulations are obsolete Fig. 8. Dorsal view of the same. Schoharie grit. Albany county. Fig. 20. An imperfect glabella with the crust nearly all removed. Fig. 21. Profile view of the same. Corniferous limestone. Falls of the Ohio. Fig. 22. A very large glabella. Upper Helderberg limestone. Near Clarence, Erie county. Fig. 23. The left free cheek. Fig. 24. Lateral view of the same. Upper Helderberg limestone. Near Clarence, Erie county. Fig. 25. A small pygidium. Corniferous limestone. Falls of the Ohio. Fig. 26. A larger pygidium, showing the characteristic curves of the axial annulations. Corniferous limestone Falls of the Ohio. Fig. 27. A large pygidium. The drawing fails to represent the proper degree of rotundity. Upper Helderberg limestone. Cayuga, Province of Ontario. Fiff. 28 (23 in error). A large, elongate pygidium. Upper Helderberg limestone. Williamsville, Erie county. Fi^r. 29. An unusually huge pygidium. Upper Helderberg limestone. Williamsville, Erie county. Kii.r. 30. Profile view of the pygidium represented in tig. 28. Fig. 31. Profile view of the pygidium represented in fig. 29. Proetus (?) lonoicaudus. Page 131. Fig, 32. Anterior aspect of the type specimen. Pig. :;:',. Profile view of the same. Fig. 42. Posterior aspect of the same. Hamilton group ! Locality doubtfidi from Somi point uurlli-uist of Des Moines, Towa, [Probably of Lower Carboniferous age.] Palaeontology of NY ( PROETiDiE ) ! ll^^U. ' ;■-. 19 1 22 20 ^k 21 25 26 29 27 24 2a ' A % 32 30 33 / 31 ,- W 34 GB. Simpson del. PhilAst hth. PLATE XXI. CviMIASPIS OKNATA. Page 145. See Plate 24. Pig1. 1. A fragment of the cephalon, showing the characteristic border. Enlarged to three diametei Hamilton group. Eighteen-miU Creek, Erie county. Proetus Row i. Page 119. See Piute 23. Kg. 2. Anterior view of an obliquely crushed specimen. Fig. 3. Posterior view of the same. Hamilton group. Summit, Schoharie county. Pig. 4. The original of Dr. Green's description, drawn from a east. Hamilton group. Otsego comity. Fig. 5. An imperfect specimen, drawn from an impression of a natural mould of the dorsal surface. Hamilton group. ( it si go county. Pig ti, A small, imperfect example, enlarged to two diameters. Hamilton group. Western New York. Fig. 24. An entire individual, enlarged to two diameters. In the drawing- the border is made to "appear too convex, and the faint lateral glabellar furrows are not represented. Tully limestone. Near drill. Seneca county. Fig. 25. A smaller individual enlarged to two diameters. The crust is broken awaj from the glabella, showing the lateral furrows very distinctly. Fig. 26. Profile view of the same, showing the normal convexity. Tully limestone. Near Ovid, Seneca county. Proetus Haldemani. Page 11:;. See Plate 23. Fig. 7. The original specimen, enlarged to two diameters. Fig. 8. Profile view of the same, similarly enlarged. Hamilton group. Pennsylvania. Fig. St. A small pygidium, enlarged to two diameters. Hamilton group. (Gonia.tite limestone.) Cherry Valley, Otsego county. PLATE XXI— Continued. Proetus MACROCEPHALUS. Page 116 See Plate 23. Fig. 10 An obliquely crushed individual, retaining the right eye and fixed cheek. Hamilton group. Canandaigua Lake. Fig. 11. A large imperfect individual. Hamilton group. Jaycox's Bun, near Q-eneseo, Livingston county. Fig. 12 An imperfect specimen, wanting- the free cheeks as is usual. Hamilton group. Cayuga Lake. Fig. 13. A portion of th phalon, showing, by compression, the glabellar furrows. Hamilton group. York, Livingston county. Fig. 14. An entire cephalon, also showing some of the glabellar furrows. Hamilton group. Canandaigua Lake. Fig. 15 The pygidium of a small individual, enlarged to two diameters. Hamilton group. Near Geneseo, Livingston county. Fig. 16. A pygidium from the limestone, similarly enlarged. Hamilton group. Eighteen-mile Creek, Erie county. Fig. 17. A pygidium, showing the internal surface and the doublure. Hamilton group. Canandaigua Lake. Fig. 18. A pygidium enlarged to two diameters, showing the axial nodes which give the animations the appearance of being medially angulated. Hamilton group. Locality ? Fig. 19. A large pygidium. Hamilton group. North Bristol. Ontario county. Fig. 20. Profile view of the pygidium represented in fig-. 15. Fig. 21. Profile view of the pygidium represented in fig. 16. Proetus occidens. Page 130. Fig. 22. A small pygidium retaining the crust, but nOt in such condition as to show the annulations with distinctness. Hamilton group? New Buffalo, Iowa. Fig. 23. A large imperfect specimen. Hamilton group? New Buffalo, Iowa: Pkoetus Conradi. Page 89. See Plates 20 and 22. Fig. 27. Anterior view of an enrolled, somewhat imperfect individual, showing the proportions of the glabella and the wide, sloping border. Fig. 28. Posterior view of the same. The axis of the body is made to appear too broad and stout. Schoharie grit. Schoharie, Schoharie county. CyPIIASPIS LjEVIS. Page 150. Fig. 29. The cephalon enlarged to twelve diameters. ( Ihemung group. Chi muni/ county. Palaeontology of NY ( PR( (E riD^E ) GB.Simpson.del. ■ PLATE XXII. Proetus angustefrons. Page 9] See Plate 20. Fig. 1. The intra-sutural portion of the cephalon, retaining the crust, showing the form of the glabella, the sloping frontal border and preserving indications of three pail's of lateral farrows. Enlarged in two diameters. Schoharie grit. Schoharie, Schoharie county. Pig. .'. Tlit* movable cheeks, preserving the visual surfaces of the eyes, showing the character of the gena) spines and the direction of the suture upon the frontal doublure. Enlarged to two diameters. Schoharie grit. Near Gla/rksmlle, Albany county. Fig. :i. A small pygidium showing the distinctly sulcate and finelj tubercled annulations, and the broad, smooth border. Enlarged to two diameters. Schoharie grit. Near Clarlssville, Albany county. PliOETI 8 < lONKADI. Page B9 See Plates 20 and 21. I i- 4. A pygidium, showing the general convexitj and the sloping borders. The lateral annulations, which are usually quite indistinct in this species, have been given too much prominence in the drawing. Enlarged to two diameters. Schoharie grit. Schoharie, Schoharie county. Proetus, sp. Page 94. Fig. 5. An imperfect cephalon retaining a portion of the crust and showing a more convex glabella and a broader and flatter border than in either of the foregoing species. Enlarged to two diameters. Schoharie grit. Schoharie, Schoharie county. Fig. ti. An internal cast of a pygidium which differs from that of the preceding species in the fewer annu- lations. Enlarged to two diameters Schoharie grit. Knox, Albany county. Proetus latimaroinatus. Page !)7. Fig. 7. A large glabella, natural size, showing the lateral furrows and the broad, Hat frontal bonier. Schoharie grit. Pendleton, Indiana. Fig. 8. The left movable cheek referred to this species. Schoharie grit. Pendleton, Indiana. Fig. 9. The right movable cheek. Schoharie grit. Pendleton, Indiana. Fig. 10. A very imperfect individual, indicating the form and proportions of the body. Schoharie grit. Pendleton, Indiana. Fig. II. The pygidium, showing the essential characters of this part of the body. Schoharie grit. Pendleton, Indiana. Fig. 12. The pygidium and a portion of the thorax of a large individual. Schoharie grit Pendleton, Indiana. Proetus curvimarginatus. Page 94. Fig. 13. A somewhat imperfect example, retaining a portion of the crust and showing the relative pro- portions of the species. Schoharie grit, Pendleton, Indiana. Fig. 14. The intra-sutural portion of a cephalon, showing the conate form of the glabella, the recurved frontal border and the four pairs and the .accessory pair of lateral furrows. Fig. 15. Outline profile of the same, showing- the elevation of the glabella and the curvature of the bonier. Schoharie grit. Pendleton, Indiana. Fig. lti. A smaller, imperfect individual drawn from a gutta-percha impression from a natural mould of the internal surface in the sandstone. Schoharie grit. Pendleton, Indiana. Fig'. 17. A small pygidium. showing the character of the annulations and the curvature of the border. Schoharie grit. Pendleton, Indiana. PLATE XXII— Continual. Fig. is. A large pygidium. Fig. 1.9. Profile of the same. Schoharie grit. Pendleton, Indiana. Proetus grassimarginatus. Page 99. See Plates 20 and 25. Fig. 20. A small pygidium, retaining the thickened border. Schoharie grit. Near Clarksville, Albany county. Fig. 21. A pygidium, preserved as a cast of the internal surface and showing the; annulations with. unusual distinctness. Schoharie grit. Near Clarksville, Albany county. Fig. 22. A fragmentary individual of large size, preserved as a cast of the internal surface. Upper Helderberg limestones. Cayuga, Province of Ontario. Fig. 'J:i. Profile view of a small pygidium, showing an abnormal prominence of the extremity of the axis. Corniferous limestone. Falls of the Ohio. Fig. "J4. Profile view of an enrolled individual, from which most of the crust has been removed. Fig. 25. Anterior view of the same specimen, showing the internal easts of the glabellar furrows, through the partially removed crust. Corniferous limestone. Sandusky, Ohio. Fig. 26. A normal pygidium. Corniferous limestone. Williamsuille, Brie county. PROETUS STEN< )1'VGE. Page ISO. Fig. 27. A pygidium, showing the short, broad, convex and obtuse axis. Enlarged to three diameters. Corniferous limestone. Phelpsf Ontario county. Proetus CLAKUS. Page 104. See Plate 20. Fig. 28. An internal east of the glabella, showing the lateral furrows. Upper Helderberg limestone. De Cewville, Province of Ontario. Fig. 29. An entire individual, somewhat flattened, but showing the characters of the species. Corniferous limestone. Lime Hock, Genesee county. Fig. ;-io. An imperfect pygidium. Corniferous limestone. Falls of the Ohio. Proetus ovifrons. Page 110. Fig. 31. An internal east of the glabella, showing its form and convexity, the size of the basal lobes, and the recurved frontal border. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. I!2. A glabella, preserving the dorsal surface and showing the pustulose character of the crust. Eu- [arged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Proetus microgemma. Page 109. Fig. 33. A normal pygidium, showing the characteristic ornamentation, and the broad border. Enlarged to two diameters. Corniferous limestone. Phelps, Ontario county. I<"ig. 34. A very small pygidium, referred with some doubt to this species. The annulations are more dis- tinct and more numerous than in the preceding specimen, a feature which may be due to a less advanced stage of growth. The axis'is covered with tine pustules, which are not represented in the figure. The relatively large size of the axial nodes give an appearance of angularity to the annulations. Enlarged to six diameters. Corniferous limestone. Canandaigua, Ontario county. PlIILLIPSIA, sp. ? Fig. '.'i~>. The pygidium. A s] imen from which a portion of the crust has been removed. Lower Carboniferous limestone. R.« : Palaeontology of NY.yolVri. J ; 4 ^ HsmL 28 30 • v. -£? ^/iV»' \ /■r 'i . aE 25 PLATE XXIII. PrOETI 8 DELPHINUH 8. Page ill. See Plate 25. Fie. 1. The cephalon, natural size, drawn from a cast of the internal surface. Fig. '-'. The same enlarged to three diameters, showing the short glabella and broad, concave bordei The light side of the glabella has been somewhat restored in this drawing. Upper Helderberg gi'oup. P I le, Provinee-of Ontarfa. Proetus folliceps. Page 101. Fig. 3. An individual retaining the parts in juxtaposition, but preserving the crust in a fragmentary state. The specimen shows the general proportions of the species, the convex glabella and the glabellar furrows. Fig. ■)■ Profile of the same, showing the convexity of the body. Comiferous limestone. Near LeRoy, Geneset county. Fig. 5. A snmewhat fragmentary individual retaining the test. Comiferous limestone. Near LeRoy, Genesee county. Fig. 6. A cephalon wanting tie- right cheek, shewing the furrows of the glabella. The drawing is made from an internal cast in chert. 7. Outline pi-ofile of the same. (Vmiferous limestone. In the drift. Ann Arbor, Michigan. Fig. 8. The pygidium represented in fig. :<. showing the peculiar markings on the internal cast of the axis, noticed in the description of the species. An enlargement to two dja ters. Proetus tdmidt >. Page US. Fig. 9. The intra-sutural portion of a cephalon, showing the tumid, rapidly tapering glabella and the broad flat border. Upper Helderberg limestones. Port Colborne, Province of Ontario. Proetus canaliculatus. Page 107. See Plate 20. Fig. 10. The dorsal surface of the movable cheeks, showing their form and the termination of the facial sutures at the anterior margin of the doublure. Fig. II. The internal surface of the same, showing the doublure and its excavation at the bases of the cheek spines. Comiferous limestone. Falls of the Ohio. PROETIS ■ ?) PXANIMARGINATUS. Page 112. Fig. 12. A view of the type specimen. (Pal. Ohio, vol. i, pi. xxiii, fig. 3.) Comiferous limestone. Sylvania, Lucas county, Ohio. Proetus Haldemani. Page 113. See Plate 21. Fig. 18. An imperfect cephalon. retaining the cpust and showing the characteristic'glabellar furrows, but having a strongly reflexed frontal border. Enlarged to two diameters. Devonian limestones. Resent Hill. Eureka District. Nevada. 14. A pygidium of a large individual. Hamilton group. Long Lake, Michigan. Fig. 15. The type specimen represented on plate 21, tigs. 7 and S, natural size. PLATE XXIII— Continued. Proetus Prouti Page 126. Fie. 16. A nearly entire individual from which :i portion of the side of the cephalon and thorax has been broken away. Fig-. 17. A profile of tin- same, showing the elevation of the body. Hamilton group. Smith's quarry, Davenport, Iowa. Fig. 18. An imperfect individual, showing the axial nodes on the posterior thoracic segments. Hamilton group. Cook's quarry, Davenport; Iowa. The specimens represented in these two figures are the originals of Proetus Davenportenxis, Barns. Proetus Nevad.k. Page 1'29. Fig. 19. A nearly entire individual, showing the elongate body, narrow glabella and small eyes. Devonian limestones. Comb's Peak, Eureka District, Nevada. Proetus Rowi. Page 119. See Plate 21. Fig. 20. A large entire individual. Hamilton group. Centerfield, Ontario county. Fig. 21. A somewhat imperfect specimen, retaining the crust and showing the glabellar furrows. Hamilton group. Eighteen-mile Creek, Erie county. Y\e. 22. A smaller, nearly entire individual. Hamilton group. Centerfield, Ontario county. Fig. 23. A young individual, showing the very large eyes. Hamilton group. Centerfield, Ontario county. Pig. 24. A still younger example. Hamilton group. < enterfield, Ontario county. Fi'r. 25. A small individual in which two of the thoracic segments have been pushed forward beneath the cephalon. Hamilton group. In the drift, Ann Arbor, MicMgan. Fig. 26. Two entire individuals of average size. Hamilton group. Centerfield, Ontario county. Fig. 27. The specimen figured on plate 21, tig. 25, drawn natural size. Tully limestone. Nit a- odd, .s, men county. Fig. 28. A small individual, retaining a portion of the test and showing the essential features of the species. Tully limestone. Near Odd, Seneca county. Fig. 29. An hypostoma. Hamilton group. Centerfield, Ontario county. Proetus macrooepiialus. Page 116. See Plate 21. Fig. 30. A nearly entire individual. Hamilton group. Canandaigua Lake. Fig, 31. The pygidium of a very large example. Hamilton group. Canandaigua Lake. Pkoktus MlSSOURIENSls. Page 133. Fig. 32. A portion of tin- cephalon. This specimen is the original of Pro, ins anriculatus, Hall (Fifteenth Kept. N. Y. Slate Cab. Nat. Hist., p. 107, 1S62), from the Waveiiy group, Licking county, Ohio. I PHOETI fJ-fi. I palaeontology of NYYoIVri. 1' ati ■ . PLATE XXIV. < Jyphaspis, coelebs. Page 161. Fie. I. An imperfect specimen, the drawing having been made Fn m a gutta-percha impression of the in- ternal surface, showing thegi-eal length of the genal spine, and the broad and rapidlj tapering a\is. Enlarged to three diameters. Lower Helderberg group. Schoharie, Sehohaiie county. ( !} PHASPIS STEPHANOPHORA. Page 1«. Fig. -'. A cephalon, having the cheeks slightly depressed along the sutures; showing the upper row of marginal spines. Drawn from a natural cast of the internal surface Enlarged to three diameters. Kg. 3. The same, drawn in profile; showing the elevation of the glabella, the convexitj of the frontal area. The figure is slightly restored to show the double row of marginal spines. Corniferous limestone. Canandaigua, Ontario county. Fig. 4. An imperfect cephalon, showing the liases of the upper row of marginal spines, and of the thi-ee short spines on the occipital ring. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. .". The internal surface of an imperfect cephalon, showing the length of the upper row of marginal spines. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. 6. An imperfect cephalon, showing the bases of the upper row of marginal spines and two spines of the lower row. Enlarged to three diameters. Fig. 6a. Outline profile of the same, with the marginal spines restored. Corniferous limestone. Canandaigua, Ontario county. Cypkaspis minuscula. rage 110. See Plate 20. Fig. 7. The intra-sutural portion of the cephalon. Enlarged to throe diameters. Schoharie grit. Near Clarksville, Albany county. Fig. 8. A similar fragment, showing the tubercles on the occipital ring. Enlarged to three diameters. Fig. Sa. Outline profile of the same, showing the elevation of the glabella and the slope of the frontal area. Corniferous limestone. Canandaigua, Ontario county. Fig. 9. An entire individual, preserved as an internal cast in decomposed chert ; showing the general form and proportions of the parts. Enlarged to three diameters. Fig. 10. The same, drawn in profile. Corniferous limestone. Canandaigua, Ontario county. Fig. 11. A larger and less perfect individual. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Pig. 12. An internal impression, showing the hypostoma slightly displaced from its normal position. En- larged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Cyphaspis DIADEMA. Page 141. Fig. 13. A portion of the cephalon, showing the strongly tubercled surface, and the single row of pustules across the frontal area. Enlarged to six diameters. Fig. 13a. Outline profile of the same, showing the depressed frontal area, and the elevate, I margin. Corniferous limestone. Canandaigua, Ontario county. PLATE XXIV— Continued. Cyphaspis hybrida. Page 144. 14. A (ragmen! of tin- cepha ./ the pustulose glabella, and the strongly punctate frontal I larged t" tin liameters Cornifen 'i- limestone. Ganandaigua, Ontario county. C'VI'II ASMS CRASPEDOTA. i'age US. l.'i. A fragment of limestone, showing one entire individual and the eephalon of another, accompanied bj two uearlj entire spi i I Dalinanites Boothi var. Callitetes. Hamilton group. Canandaigua, Ontario county. Fig. 16. Thee men in the foregoing figure, enlarged to three diameters, retaining- the ciTiat, with ion of the eyes and two of the axial spines, and showing the proportions and characters Fig. 17. Profile of the same, with the th racic spines restored. l individual, viewed in profile. Enlarged to three diameters. 19. Front view ' f the same, showing the elevation of the eyes, which have been restored from another UUill. Hamilton group. Canandaigiia, Ontario county. Fig. 20. A pygidium. Enlarged to six diameters. Hamilton group. Canandaigua, Ontario county. Cyphaspis ornata. Page 145. See Plate 21. Fig. 21. A portion of the eephalon, showing the bead-like tubercles on the frontal margin. Enlarged to three diameters. Fig. 21a A profile of the same in outline, showing the frontal depression and elevated margin. Hamilton group. Canandaigua, Ontario county. CYPHASriS ORNATA, v;ll'. BACCATA. I'age 146 22. A fragment oi a eephalon, enlarged to three diameters. The drawing fails to show with sufficient emphasis the axial of the glabella, which, .serves as a varietal feature. I 22a. Outline profile of the same, showing the contour of the head-shield. Hamilton group. Canandaigua, Ontario county. \ portion of the right tree cheek, showing the marginal ornamentation and the broad, rapidlj tapering spine. Enlarged to three diameters. Hamilton group. Canandaigua, Ontario county. Phaethonides Macrobius. Page 139 24. The intra-sutural portion of the eephalon, natural size. The drawing shows one pair of lateral glabellar furrows, but fails to indicate the fainter anterior pair. J4a. Outline profile of the same, showing the position of the lateral glabellar furrows. Lower Helderberg group. Square Lake, Maine. l pygidium of this species. Enlarged to three diameters. Lower Helderberg group. Square Lake, Maine. iirei are introduced for comparison with the New fork species of this genus. l M' ; Plat.. 29 a 30 41 3', - ■ PLATE XXIV— Continued. PllAETHONIDES CYCLURUS. Page 137. See Plate 25. Fig. 26. A fragment of the cephalon, showing the lateral furrows of the glabella, a little too strongly. Enlarged to three diameters. Fig. 26a. Outline profile of the same. Lower Helderberg group. Near ClarksviUt. Albany county. Fig. 27. A pygidium, drawn from a gutta-percha impression of the internal surface The axial row of tubercles should be represented a-s duplicate at the fifth annulation, as in fig. 28. Enlarged to three diameters. Lower Helderberg group. Near Clarksvitte, Albany county. Fig. 2S. Another pygidium retaining the crusf and showing the character of the dorsal surface. Enlarged to three diameters. Lower Helderberg group. Near C larksville, Albany county. Phaethonides varicella. Page 135. Fig. 29. The intra-sutural portion of a cephalon, showing the tubercled and punctate surface. Enlarged to three diameters. Fig. 29a. Outline profile of the same, showing the depressed frontal area and elevated margin. Corniferous limestone. Canandaigua, Ontario county. Fig. 30. An imperfect cephalon, drawn from a natural cast of the internal surface. Enlarged to three diameters. Fig. 30a. Outline profile of the same. Corniferous limestone. Canandaigua, Ontario county. Fig. 31. A pygidium, drawn from a natural cast of the internal surface. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Phaethonides GEMM.EUS. Page 136. Fig. 32. A pygidium, showing the characteristic ornamentation. Enlarged to two diameters. Hamilton group. Canandaigua. Ontario county. Fig. 33. Another pygidium. The axial node on the posterior margin is made too distinct in the drawing. Enlarged to two diameters. Hamilton group. Eighteen-mile Creek, Erie county. Fig. 34. A fragment, showing seven segments of the thorax. Enlarged to two diameters. Hamilton group. Canandaigua Lake. Fig. 35. A pygidium, drawn from a gutta-percha impression of the internal surface which retains the doublure, showing the strongly punctate character of the surface between the ribs. Enlarged to three diameters. Corniferous limestone. Canandaigua, Ontario county. Fig. 36. A small pygidium in which the marginal tubercles are unusually conspicuous and become spini- form. Enlarged to two diameters. Corniferous limestone. Canandaigua, Ontario county. PLATE XXV. Calymene platys. Page 1. See Plate 1. ], \n . xii.Mii.'K large pygidium, retaining, onb/, a sinall portion of the crust. Accompanying this is -111 outline restoration drawn upon the basis of this pygidium, to indicate the dimensions the animal maj have attained when entire. Normally the pygidium of the animal is somewhat incurved, as shown in tig. 2. In this drawing the pygidium is viewed from behind, ami not from above, appearing therefore detached from the restored thorax. Corniferous limestone. Falls of tlu Ohio. I _ 2. A large, somewhat imperfect individual, retaining the parts' iri juxtaposition. Upper Helderberg limestone. HagersviU'e, Prov'i nre of Ontario. \ ? | Phacops 1IANA. Page 19. See Plates 7, 8 and Sa. Fig. ::. A cephalon from which the crust has been removed : showing the glabellar furrows, the deep and broad occipital furrow, made more conspicuous by the obsolescence of the third or basal lobes. I .■... 4. A profile view of the same, showing the somewhat protuberant and slightly flattened glabella, the subangulate genal extremities and the elevated occipital ring. This specimen is from the Eureka District, Nevada, and shows a close relationship to Phacops cristata in the broad and deep occipital furrow and other features. (See page 25.) LlCHAS (HOPLOLICHAS) HYLvEUS. Page 81. See Plate 19 b. Pip., :,. An in postoma, found in association with the cephalon of this species. Enlarged to two diameters. Upper Helderberg limestone. North Cayuga, Prmrince'bf Onitarvol Proetus DELPHINULUS. Page 111. See Plate 23. Fig. 6. The cephalon represented on plate 2ii. figs. 1 and 2: drawn from a gutta percha impression from a natural mould of the dorsal surface, showing the character of the glabellar lobes and fur- rows. Enlarged to three diameters. Proetus jejunus. Page 124. Fig. 7. The pygidium enlarged to two diameters; showing the axial row of nodes and the broad pleura? with their bifurcate annulations. Hamilton group. Albany county. Proetus crassimarginatus. Page 99. See Plates 20 and 22. Fig. 8. The axis of the pygidium enlarged to two diameters. The internal cavity of the axis has been tilled with I ii nt calcite. and by the removal of the outer portion of the test, the position and character of the muscular sears upon the lower surface are very distinctly shown, liferous limestone. Falls of tlu Ohio. |;l Mill 1TA Ml SCE I. I. A.N 'alseon* *>V '•■' PLATE XXV— Continued. Proetus Phocion. Page li5. Fig. 9. A very imperfect enrolled specimen, retaining the crust, showing the broad sulcate border ami the flattened, sharply ridged cheek. Hamilton group. In.li.ni Cove, Gfasp&, Provinei of ',""'" Pig. It). The type specimen : an entire individual preserved as an internal nasi, showing the relatively stoul body, the shaiply ridged cheeks and the sparsely annulated pygidium. Hamilton group. Indian Cove, Cfaspi, Provinei of Quebec. Phaethonides cyclukus. Page 137. See plate 24. Fig. il. The intra-sutural portion of the ceph&lonj showing fcnle character of tin' surface ornamentation. Lower Helderberg group. Near Clarksville, Albany county. PlIAETHONIDES ARENICOLIS. Page 134. Fig. 12. An imperfect pygidium, enlarged to three diameters, showing th inspicuous axis, the marginal spinules and the liases of other spinules on the annulations Schoharie grit. Schoharie county. Fig 13. A larger pygidium, preserved as an internal nasi and referred with much hesitation to this species. Enlarged to two diameters. Upper Helderberg limestone. North Cayuga, Province of Ontario. PliAETHONIDESS (?) DENTICULATUS. Page 139. Fig. 14. A portion of the cephalon, shewing the Proetoid glabella with its distanl lateral furrows. Fig. 15. The pygidium which is taken as the type form of the species. These figures are reproduced from the original engravings (U. S. Geol. Expl. Fortieth Parallel, pt. 1. Palaeontology, pi. I, figs. 10 and 10a), and are enlarged to about one and one-half diam- eters. The specimens have not been accessible for study and the species is referred with greal doubt to the genus Phaethonides. Devonian. iSteptoe Valley, Nr.vada. PLATE XXVI. Stylonurus excelsior. Vane 158. View of the cephalon described. The drawing has been made from a plaster cast taken from a natural mould of the dorsal surface. Catskill group. Andes, Delaware county. PLATE XXVI a. Stylonurus EXCELSN >li. Pages 156, 221. See Plate 26. Fig. 1. Tin' lower surface of the type specimen of Dolichocephala Lacoana, Claypole, showing- portions of the cephalic appendages. These have all been pushed somewhat forward from their proper position beneath the carapace, but as far as they are retained, appear to lie normally with reference to one another. The restored parts, where their outline is not indicated by the specimen itself, are drawn from figures of Stylonurus given by Woodward (Palseontographical Society, 1872). A. A fragment of an appendage preserved as an impression upon the edge of the slab, and drawn in from a gutta-percha east It probably represents a portion of a long first pair of gnathopods. B. The right member of the second pair of gnathopods, showing the long basal joint, a portion of which is buried beneath the matrix, its denticulate mandibular edge, and the long recurved palpus. A portion of the basal joint of the left member of this pair is also visible. C. A chelate terminal joint, possibly belonging to the first pair of appendages. D. The basal joint of the left member of the third pair, showing the double lamellate mandibular processes. E. A portion of the basal joint of the left member of the fourth pair, showing the mandibular margin. F. The left basal joint of the fifth pair of gnathopods, showing the broad surface, the conspicuous mandibular denticles, and the prominent surface of articulation. G. The position of the mouth. H. The outline of the carapace as if lies on the other side of the specimen. Fig. 2. The terminal portion of the median dorsal ridge, drawn from the same specimen, showing tlw ocelli, which are separated by a sharply impressed line and are slightly distorted. No evidence of this feature is shown upon the specimen represented on plate 20. Fig. 3. A portion of the carapace, natural size, showing the conspicuous, elongate tubercles, and, over the surface where the thin crust has been removed, impressions of the sharply defined, semicircu- lar squamse upon its lower side. Catskill group. Meshoppen, Wyoming county, Pennsylvania. PLATE XXVII. Pkotolimulus Eriensis. Page ia:i. Kiir- 1. A view of the ventral surface from the original cast in sandstone, showing the condition of preserva- tion of the different parts. Chemung group. LeBceuf, Eric county. Pennsylvania. Fig. 2. A diagram of the same : cil. Cephalic doublure, s. Genal spines. x. Hypostoiiia ('.}, or axial angulation of cephalic doublure. m. Position of mouth. ca. Cephalic appendages. f. Foliaceous terminations of the bust pair of cephalic appendages. tp. Thoracic plate, r. Longitudinal abdominal ridges, m. Marginal abdominal spines, t. Telson. EURYPTERUS PROMINENS. Page 157. Pig. 3. The cephalon, showing the prominent and anteriorly situated eyes, the ocelli, the flattened dorsal surface, and the oblique postero-lateral pits. Fig. 4. Profile view of the same, showing the elevation of the shield, the position of the eyes ami the extension of the postero-lateral angles. Clinton group. From the northern part, of Cayuga county. EURYPTERTTS BeECHERI. Pago 156. Fig. 5. Dorsal view of the original specimen, showing the form of the body, the number, size and orna- mentation of the somites, and portions of the large swimming appendages. The drawing is made from a plaster cast taken from a natural mould of the dorsal surface. Chemung group. Warren, Warren county, Pennsylvania. EURYPTERUS APPROXIMATES, 11. sp. Pig. 6. Dorsal view of the original, showing the cephalon and nine somites, also the conspicuous marginal spines and the characteristic ornamentation of the surface. Waverly group. Three miles south of Warren, Warren comity, Pennsylvania. This species differs from E. Pennsylvanicus, C. E. Hall, in the absence of genal spinules and con- spicuous nodes on the posterior margin of the cephalon, and in the more closely appressed eyes. In E. Mansfieldi. C. E. Hall, from the Coal Measures, the cephalon is longer, the eyes more distant, and the abdominal segments scarcely as broad. PLATE XXVII— Continued. Stylonurus (?) (Echinocaris?) Wrightianu*. Page 160. Pig. 7. Dorsal view of the type specimen of Equisetides TVriglitlanus, Dawson. The specimen consists of two abdominal somites of this crustacean* preserved as an internal cast in sandstone and showing tin; pustulose ornamentation, the conspicuous ridges along the posterior margin of each somite and the character of the articulation between the somites. On the anterior surface of the last somite several longitudinal impressions are seen, apparently made by the long posterior spines of the preceding somite. Fig. 8. Side view of the same specimen, showing the character of the articulation, the strong marginal ridges and the smooth ventral surface. The specimen has been slightly flattened, vertically making the convexity of the somites somewhat less than it should normally be. Fig. 9. An enlargement of the surface to show the character of the ornamentation. Portage group. Italy, Yates county. Echinocaris punctata. Page 166. See Plates 28 and 29. Fig. 10. An enlargement of the surface of an abdominal somite from the specimen represented on plate 28, tig. 4. Introduced for comparison with the preceding figure. Hamilton group. Ticltenor's Point, Canaitdaigua Lake. I 1.1 M LT.II).!^ > i . Paleontology of PLATE XXVIII. ECHINOCARIS PUNCTATA. Page 166. See Plates 27 and 29. Fig. 1. The left valve of a specimen of average size, showing the normal outline and proportions, pre- serving the nodes and ridges of the surface in perfection, and retaining the faint, elevated lines radiating from the lower edge of the carina. The specimen is preserved as an internal cast and consequently shows a finely punctate surface. Fig. 2. The right valve of the same individual. Hamilton group. In the sandy shales at Faluns, Onondaga county. Fig. 3. A nearly entire individual, slightly distorted about the cephalothorax ; showing the six abdominal somites, the spine-bases on their posterior margins, the caudal plate and portions of the caudal spines. These spines are restored in outline to their proper length. Hamilton group. Pratt's Falls, Onondaga county. Fig. 4. Ventral aspect of a very large individual, showing the lower edge of the right valve of the cephalothorax, the large mandibles in nearly their normal position, the fourth, fifth, sixth and a portion of the third abdominal somites, and the caudal plate with its spines. The posterior margin of the somites is so broken as to show only the lateral spinules, and the caudal spines appear to be somewhat shorter than is usual. Hamilton group. Mi nteth's Point, Canandaigna Lake. Fig. 5. The ventral surface of a small, quite imperfectly preserved specimen, showing the mandibles in place. Hamilton group. Pratt's Falls, Onondaga county. Fig. ti. Dorsal aspect of the posterior port ion of a large individual, preserving the fifth, sixth and a portion of the fourth somites, with the caudal plate and spines nearly entire. The spinules upon the somites are in part restored in the figure, but their character is well shown. ■Fig. 7. Ventral aspect of the same specimen, showing the absence of spinules upon the posterior margins of the somites, and the character of the articulation between the last somite and the caudal plate is well shown. Hamilton group. Menteth's Point, Canandaigiia Lake. liLiN... .. ZD38 ( CEHATK >l. VHIII.r Paleontology of NY yoML Iex Pi l y j ;i ■c-.^, i p i 1/ ■ PLATE XXIX. ECHINOCAEIS PUNCTATA. See Plates 27 and 28. Fig. 1. An enrolled individual of average size, having the carapace somewhat compressed, bul showing the position of the optic spots (e), the number and disposition of the nodes, a well-defined nuchal furrow and the tubercles along the posterior portion of the hinge-line. A single caudal spine is seen projecting from beneath the anterior portion of the carapace. Fig. 2. Profile view of the same, showing a portion of the enrolled abdomen. Hamilton group. Pratt's /•'tills. Onondaga county. Fig. 3. A nearly entire individual, showing the valves of the carapace fully expanded and the six abdom- inal somites, which are detached from the carapace. The caudal parts are missing and are restored in outline. Hamilton group. Pratt's Falls, Onondaga county. Pig. 4. A specimen showing the post-abdomen and a portion of the internal surface of the last two somites of the abdomen. Hamilton group. Pratt's Falls. Onondaga oounty. Pig. 5. An expanded carapace covered with individuals of Discina media, Hall, not an infrequent mode of occurrence at this locality. Hamilton group Pratt's Falls, Onondaga county. Pig. fi. A portion of the surface of the carapace represented in plate 28, fig. 2, enlarged to two diameters to show the character of the ornamentation between the carina and the ventral margin. The specimen is a cast of the internal surface, and shows the strong punctse which become still more conspicuous near the lower edge of the carina, and the elevated, undulating lines radiating from the carina. Upon the upper surface of the test the ornamentation is distinctly pustulose and the radiating lines are scarcely visible. Hamilton group. Fahius, Onondaga county. Fig. 7. An imperfect specimen, showing the internal surface of the left valve of the largest carapace observed. In the cephalic region there lies a single large mandible which shows no denticles, but bears a conspicuous manubrium. The posterior margin of the valve bears three strong tubercle-, a featuife usually but faintly developed in smaller individuals. Hamilton group. Vinegar Brook Grlen, Cayuga Lake. Fig. 8. A large right valve, showing normal proportions and the position of the optic spot, but wanting the elevated lines on the ventral surface and the posterior marginal tubercles. This is the type specimen of Ceratiocaris > punctata, Hall, and was originally figured with a conspicuous node near the posterior extremity of the hinge-line; this, however, has proven to be a portion of the matrix. Hamilton group. Cayuga Lake. EOHINOOARIS PUSTULOSA. Page 178. Fig. 9. The type specimen ; a light valve showing the number and disposition of the nodes, the character of the carina and the strong pustules upon the surface of the nodes. A portion of the cephalic region is broken away and is restored in outline. Pig. 10. The same, enlarged to two diameters. Erie shales. (Portage group.) Paine's Creek, Lake county, Ohio. PLATE XXIX— Continued. ECHINOCARIS SUBLjEVIS. Page 176. Fig. 11. The type specimen ; drawn from a, gutta-percha impression of the internal surface of the left valve, the posterior portion being slightly restored ; showing the number and arrangement of the nodes, the character of the carina and of the surface ornamentation. Pig. 12. The same, enlarged to two diameters. Erie shales. (Portage group.) Paine's Creek, Lake county, Ohio. Pig. 13. A portion of the abdomen and post-abdomen belonging to the carapace ; showing the relatively short somites, their conspicuous lateral and faint dorsal spines, the elevated caudal plate and comparatively short caudal spines. Enlarged to two diameters. Erie shales. (Portage group.) Paine's Creek, Lake county, Ohio. ECHINOCARIS CONDYLEPIS. Page 173. Fig. 14. The expanded valves of the carapace, natural size. Fig. 15. The same, enlarged to three diameters, showing the outline of the valves, the number and disposi- tion of the nodes upon the surface, and the character of the lateral carinae. Chemung group. Belmont, Alleghany county. Fig. 16. A left valve somewhat compressed at right angles to the axial line and having the anterior extremity slightly broken. Fig. 17. The same, enlarged to four diameters, showing the nodes to be somewhat elongated on account of distortion. Chemung group. Belmont, Alleghany comity. ECHINOCARIS MULTINODOSA. Page 180. Fig. 18. The type specimen of the species, showing the features of the dorsal surface of the carapace. The lateral carina, which appears to be of similar character to that in E. sublwvis, is not well preserved, as the specimen has suffered some distortion about the ventral margins. Erie shales. (Portage group.) Paine's Creek, Lake county, Ohio. Fig. 19. An imperfect specimen, showing with great distinctness the character of the nodes and ornamenta- tion about the hinge. Erie shales. (Portage group. ) Paine's Creek, Lake, county, Ohio. ECHINOCARIS WHITFIELDI. Page 172. Fig. '20. The left valve of the carapace, showing the outline and proportions, the low, indistinct nodes upon the surface and the short antero-lateral carina. The fine scaly surface markings about the cephalic nodes is not shown. This is the type specimen and is enlarged to two diameters. Portage group. Naples, Ontario county. Fig. 21. An imperfect specimen, natural size, retaining the caudal plate and two of the caudal spines ; showing the strongly tuberculose surface. Portage group. Naples, Ontario county. : I < KKATIof AUlf >.!•' ) Paleontology of NYyoIVTL Plate ■ PLATE XXX. ECHINOCARIS SOCIALIS. I'age 171. Fig. 1. A very young, entire iiMliviiln.il representing the earliest stage of growth observed. Chemung group. Warren, Warr ;„. Fig. •-'. A young individual in whirl, the abdomen is benl dorsally. Chemung gi-oup. Warren, Warren county, Pennsylvania. Fi-- :!- A" fixi le with the valves •• | and the abdomen protruding from the anterior margin of tin' carapace. Chemung group. Warren, Warren county, P unia. Fig. 4. An individual with the valves expanded and the abdomen closelj curved around 11." posterioi margin of the left valVe. Chemung igrou|). Warren; Warr Pennsylvania. Pig. 5. The expanded valves of a larger iridividual. Chemung group. Warren, Warren county, Pennsylvania. Pig. G. A larger, expanded carapi stoixtewhal enlarged, showing more distinctlj the character of the surface ornamentation. Chemung group Warren, Wan-en. county, Pennsylvania. Fig. 7. A nearly entire ma ,,,1". enlarged to two diameters, showing the arrangement of the sp^ules on the abdominal somites, and the very slender caudal spines. The anterior tion ' f tin- carapace is somewhat restored in the drawing. Chemung group. Warren, \farren county, Pennsylvania. Fig. 8. The righl valve of a Uirge carapace will, the abdomen attached. Chemung grqup. \\'A. Page 170. Fig. 13. A large specimen, natural size, showing the molar-like appearance of all the denticles except the posterior one, which is sharp and composed of a single cusp. Hamilton group. Pratt's Falls. Onondaga county. Fig. 14. A specimen preserving the " manubrium " and showing the number and character of the cusps Hamilton group Pratt's Falls, Onondaga county. Fig. If.. The crown ol a large example. Hamilton group. Pratt's Falls. Onondaga manly. Fig. 16. A small example, showing but five cusps. In (his specimen the basal portion of the mandible is not distinctly separated from the crown. Hamilton group. Pratt's Falls, Onondaga county. Fig. 1 ,. A somewhat larger specimen, with a strong terminal cusp. Hamilton group. Pratt's Falls, Onondaga county. PLATE XXX— Coutinued. Fig 18 A larger example, retaining the "manubrium." Hamilton group. Pratt's Falls, Onondaga county. Fi* 19 A specimen in the shale, from which the crust has been removed, showing the thickness of this c,.„st over the crown and its comparative tenuity on the basal portion of the mandible. Hamilton group. Pratt's Falls, Onondaga county. Pal^opal.kmun Xewberryi. 1'age 203. Fiir 20. Lateral view of the type specimen, natural size. ml 21 The same view, enlarged to two diameters, showing the somewhat crushed and broken carapace, the bases of the strong antennas, the basal portion of an ocular peduncle, a joint of a maxillary nalv,us(1) and fragments of five pairs of ambulatory appendages. The abdomen is incurved, and is composed of five somites, the first two of which bear the bases of natatory appendage,. The tail is expanded, and the posterior portion of it has been abraded. Fig. 22. Dorsal view of the same specimen, natural size, showing the prominence of the antenna-, the carina on the carapace, and the incurvature of the abdomen. Fig 23 The tail, enlarged to two diameters, showing the broad, stout telson, the lateral spmes with then- short basal joints, and the flat, tenuous lamellar spines lying in the membranous expansion. Erie shales. (Portage group.) LeRoy, Lake county, Ohio. Tkopidocakis IIamiltoni.k, ii. sp. Fig. 24. The type specimen, natural size. , Fig 25 The same, enlarged to two diameters. The specimen is folded along the hmge-lme, the edge of the right valve being seen within the ventral margin of the left. The outline of the carapace is closely similar to that of T. bivaHnata of the Chemung group, being narrow near the ante- rior extremity, rapidly widening posteriorly. Both dorsal ami ventral margins are elevated and ornamented by transverse striatums. A single nearly straight carina lies on the middle of each valve, and this is also striated along its summit. An eye-node is visible near the anterior extremity of this carina. . This specimen was obtained too late to permit a notice of the species in its proper place m the text. Hamilton group. In the uppermost beds of the shales. Foster's, Canandaigua Lake. lU\\vrrrr_rmxJ _fn CIS ■ | EKE?. (CEHATIOCAHID/E & CAKID7D.-E J Pi „>"■> ^10 ( AM L .J 23 jLs^ 24 J PLATE XXXI. Cebatiocaris longioauda. Page 1 Fig. 1. The type specimen enlarged to two diameters, showing the last two somites and two of the caudal spines. Genesee shales. Bristol Center, Ontario county. CeRATIOCAEIS (?) SIMPLEX. Pago 165. Fig. 2. The type specimen, natural size; an internal cast of the lefl valve of the carapace. Portage group. Naples, Ontario county. Ceratiocaris Beecheri. Page 164. Fig. 3. The type specimen, consisting of a portion oi the abdomen and caudal spines j showing the absence of surface ornamentation and the short, relatively stout rercopods. Portage group. Son Yea, Livingston county. Elymocaris CAPSF.LLA. Page IS1. Fig. 4. A carapace, enlarged to two diameters; showing the siliquoid form of the valves, the minute spine at the anterior extremity of the left valve and the absence of surface ornamentation, with the exception of the characteristic longitudinal stria? near the margins. Hamilton group. Tichenor's Qltn, Canandaiyua Lake. Elymocaris siliqua. Page 182 Fig. 5. 4 specimen showing the posterior portion of the carapace with the abdomen and post-abdomen. The anterior portion of the valves is restored in outline. Chemung group. Warren. Warren county, Pennsylvania. Fig. 6. The separated valves of a carapace, showing their form, the position of the eyes and the cephalic nodes. Chemung group. Warren, Warren county, Pennsylvania. Tropidooaris bioarinata. Page 184. Fig. 7. A carapace with the valves expanded, showing their form and proportions, the position of the eve- nodes, the character of the surface ornamentation and the size and of the rostral plate. The drawing is made from a plaster cast taken from a natural mould of the dorsal surface and is partially restored. Chemung group. Warren, Warren county, Pennsylvania. Fig. S. A smaller carapace, the valves of which are somewhat crushed; showing the rostral plate, one of the eye-nodes and the large lunate nodes on the outer edge of the principal carina. Chemung group Warren, Warren county, Pennsylvania. Fig. 9. The anterior portion of the specimen represented in tig. 7, enlaiged to two diameters; showing the rostral plate, which bears a shaip carina along the axial line and a fainter one on either side. This plate in the specimen is tilted a little to the right. Hs.'. 10. The anterior portion of the carapace represented in tig. 8, enlarged to two diameters, showing the rostral plate m >mewhat displaced and tilted, the spinule at the extremity of the right valve, and the surface markings of the carapace. PLATE XXXI— Continue.! Fiff. 1 1. The right valve of a small individual, slightly broken at the anterior extremity, lmt showing the sharply angular posterior extremity of the hinge. This valve is somewhat broader posteriorly than that represented in tig- 7, and as it appears to be uncompressed this outline is probably correct for the species. Chemung group. Warren, Warren county, Pennsylvania. Pig. 12. Two of the abdomen and a portion of the telson, referred with doubt to this species. The drawing is enlarged to two diameters to show the character of the surface markings. Chemung group. Warren, Warren county, Pennsylvania. Tropidocaris interkupta. Page 185. Fig. 13. A right valve of the carapace, showing the form and surface ornamentation. Chemung group. Warren, Wan-en county, Pennsylvania. Tropidocaris alternata. Page 186. Fig. 14. An imperfect left valve, showing the numerous carinas and the nodes in the cephalic region. Waverly group. Warren, Warren county, Pennsylvania. Fig. 15. Another imperfect left valve, showing the carinas and bearing the impression of plates of an echinoderm. Both this and the preceding figure have been drawn from gutta-percha impressions taken from natural moulds of the dorsal surface. Waverly group. Warren, Warren county, Pennsylvania. Rhinocaris columbixa. Page 19S. Fig. U'>. A carapace which has been laterally compressed, but retains the prora. Near the dorsal margin is seen the line along which the carapace has been fractured. The surface shows no ornamen- tation except the faint striae along the margins. Fig. 17. The anterior portion of the same specimen, enlarged to two diameters to show the character of the prora. The carapace has been fractured near the base of the prora, but upon the dorsal sur- face the latter is continuous with the shield. Hamilton group. Tickenor's Glen, Canandaigua Lake. Fig. 18. A portion of the carapace upon which lies a very small mandible. The specimen is enlarged to three diameters. Hamilton group. Vinegar Brook Glen, Cayuga Lake. Fig. IS*. A fragmentary specimen, showing a portion of the carapace, three segments of the abdomen, the sub-conical caudal plate and telson, with the cercopods. Hamilton group. Vinegar Brook Glen, Cayuga Lake. Kig. 20. The posterior portion of a large carapace, showing the character of the posterior margin. Hamilton group. Tichenor's Glen, Canandaigua Lake. Fig. 21. An imperfect specimen retaining one side of the carapace, showing the last abdominal segment and the telson. Hamilton group. Eighteen-mile Creek, Erie county. Rhinocaris scaphoptera. Page 197. Fig. 22. A view of the left side of a carapace which has been crushed along a line lying to the left of the axis, making this side appear narrower than is normal ; showing the prora, the conspicuous lateral carina and the surface ornamentation. ! 23. The anterior portion of the same specimen, enlarged to two diameters to shew the character of the prora, which is continuous with the carapace. Hamilton group. Tichenor's Glen, Canandaigua Lake. I CKltATIc M AKlll.l- A Hill X OI'.MII n F. ) Palaeo >i NYVoIVtl. P iti Phil A PLATE XXXII. Mesothyra Ooeani. Pnge 187. Fig. 1. An outline restoration it at its summit. i \ similar enlargement of the optic node of the valve shown on plate 33. fig. 5. I 4. A portion of the carina on the valve represented upon plate 33, tig. 4. enlarged to three diameters. The lateral slopes arc divided by a sharply impressed longitudinal line into a punctate lower portion an«l an impunctate, gently crenulated summit. Fig. .">. A portion of the right cei pod of the post-abdomen shown on plate 34. fif,'- 4. enlarged to threi diameters ; showing the impressions of the setse, their bases of attachment along the inner margin of the spine and the coarsely tubercled and ridged surface. Pig, 6. The hinge angle of the right valve figured on plate 33, fig. 4, enlarged to three diameters ; show- ing the thickened apex, curved upward and inward for articulation with the left valve, and the tubercled and punctate surface. Mesothyra Xeptuni. Page 191. Fiur. 7. A portion of the light cercopod of the specimen represented on plate 33. fig. 1 ; drawn to show more distinctly the character of the surface ornamentation. Hamilton group. Plainfield, Otsego county. Mesothyra spum^ka. Page 193. Pig. s. ,\ nearly entire caudal spii f this species. Fig. 9. A portion of tin- same, enlarged to three diameters, to show tho character of the surface ornamen- tation. Hamilton group. Delphi, Onondaga county. WSSSSSSS D"i?r Ik IF© LE1"JJ A B IE BIB U "If IP £ _, ^alffiontoiogy of NYVoMt '] PLATE XXXIII. Mesothyra Neptuni. See Plate 32. m. 1 View of the tj pe specimen, natural size, showing the dimensions of the caudal plate and spines rtronglj striated urf s of the latter and the ridges on the inner margins of the lateral spines for the attachment of the sets. Hamilton group. Plainfield, Otsego county. Mesothyra spumjsa. See Plate 32. «„ 3 Ventral aspect of the caudal plate and cercopods. The latter have been broken at about one- ,,.,!,- their length, but the remaining portions show the faint pustules upon the surface accompanied by eleyated strise near the articular margins. Hamilton group. Pratt's Falls, Onondaga county. Mesothyra (Dithyrocaris ?) Veneris. Page 193. The right valve of the carapace flattened in the shale, showing the outline, the acute anterior and posterior spines, the position of the eye-node and the faint lateral carina. ^specimen also Fig. 3. shows a longitudinal furrow just within the dorsal margin, which merges into the margin at a ly opposi milton g point directly opposite the eye-node. Hamilton group. In the Marcellus shales on Mud Creek, East Bhomfield, Ontario Mesothyra Oceani. See Plates 32 and 34. FV A A very large, somewhat imperfect left valve, showing the prominent hinge-angle and its upwardly curved apex, the strong lateral carina and the ornamentation of its inner slope, and the con- spicuous eye-node. Portage group. Ithaca, Tompkins county. Fig 5 A smaller specimen of the left valve of the carapace, showing the characteristic surface features and the continuation of the thickened margin into the posterior spine which has been broken away. Portage group. Ithaca, Tompkins county. Pis 6 \ somewhat .-rushed and imperfect specimen of the abdomen and post-abdomen, showing the .. anterior somite and the longer posterior somite with retrally directed strife. The cer- pods show the strong marginal striatums and the coarse, scattered tubercles. Portage group. Ithaca, Tompkins county. Fig. 7. The post-abdomen, with a portion of the posterior somite : showing the sets attached to the inner margins of the cercopods. The drawing fails to represent with sufficient prominence the striatums and tubercles on the cercopods, and the telson, as represented, is considerably too short. Portage group. Ithaca, Tompkins county. I «' KIIATIDI AH1 II! Palaeontology of NY.VolVIL PLATE XXXIV. Mesothyra Oceani. See Plates 32 and 33. Fie. 1. The carapace of a large individual, the left valve of which is quite imperfect. The rig-lit valve shows the characteristic features of the genus and species. Portage group. Ithaca, Tompkins county. Fig. 2. A light valve of the carapace, proportionally somewhat narrower than that in the preceding figure. Portage group. Ithaca, Tompkins county. Fig-. :-;. A specimen retaining the posterior abdominal somite and the post-atxjomen ; showing the true proportions and the characteristic ornamentation of these parts. Fig. 4. The ventral aspect of a small post-abdomen, showing the triangular outline of the caudal plate, the characteristic surface ornamentation and the setaceous fimbria- on the eercopods. Portage group. Ithaca, Tompkins cownty. 5 A small specimen retaining the abdomen and post-abdomen, enlarged to two diameters The parts of the abdomen are incorrectly represented as one piece, the articular surface of the two somites being at the broken line about one-third the length of the abdomen from the anterior margin. The cancellating striations on the posterior somite are partially due to lateral compression. Portage group. Ithaca, Tompkins county. Paleontology of N YYoIVTI. I (ED \;-i< >< aki 1 1 ! w f . PLATE XXXV. S. in/,. (DISCI S CAPSA. Page 209. Fig. I. A specimen retaining both valves of the carapace, and showing the characteristic features of the species. Enlarged to thr liameters. Fig. 2. Profile of the same, similarlj enlarged, showing the elevation of the beaks. The surface is s e- \vh:it less convex in this specimen than is usual. Hamilton group. Near Centerfield, Ontario county. Fig. 8. A somewhat smaller ami re convex carapace, the valves of which have 1 a very slightly displaced. Enlarged to three diameters. Fig. 4. The internal surface of the same specimen, similarly enlarged Hamilton group. Near Centerfield, Ontario county. Fig. 5. The right valve of a carapace which is, much narrower at the posterior extremity than is usual. Enlarged to three diameters. Hamilton group. Near Centerfield, Ontario county. Fig. 6. A small example, tin' valves of whicli are folded ami slightly disph 1. tln> posterior extremity of the right valve being broken away. Enlarged to three diameters. Hamilton group. Wear Centerfield, Ontario county. Fig. 7. A very small carapace, natural size. Fig. S. Th,' same, enlarged to three diameters. Hamilton group. Near Ceuti i-jhhl. Ontnrin founty. Fig. 9. An individual of normal proportions, natural size. Hamilton group. Near Centerfield, Ontario county. ESTHERIA PULEX. Page 206. Fig. 10. A fragment of -halo bearing several individuals of this species, and various Ostracoda of other ' genera The position of the individuals of Estkeria are marked bj a cross (X). Fig. 11. A portion of the same fragiridnt'enlarged to twenty-five diameters, showing five valves of Estheria, the distances between which have been proportionally much diminished in the enlargement. Hamilton group. Miles' Gully, Hopewell, Ontario county. Spathiocaris Emersoni. Page 199. Fig. 12. A large individual which has been unsymmetrically folded along the dorsum. Portage group. Xii/ili*. Ontario county. Fig. 13. Avery large example somewhat foreshortened in front, preserving normal convexity over the anterior and lateral areas, but compressed along the dorsum ; showing the concentric lines ami ridges and the fine radiating stria upon the dorsum. Portage group. Naples, Ontario county. Fig. 14. A carapace which is symmetrically folded along the dorsum, showing the elevation of the apex and the relative length of the anterior cleft. Portage group. Naples, Ontario county. Fig. 15. The type specimen, showing the normal proportions of the species. Portage group. Naples, Ontario county. Fig. 16. A small, somewhat distorted example. Portage group. Naples, Ontario county. Fig. 17. An individual of about the same size as that represented in the preceding figure, but uncompressed. Portage group. Sparta, Livingston county. Fig. IS. A young-example, showing the short carapace and verj broad anterior cleft. Portage group. Naples, Ontario county. Fig. 19. Th. smallest carapace observed. Portage group. Naples, Ontario county. PLATE XXXV— Continued. DlPTEROCARIS PES-CERV^. Page '-»o:. Fig-. 20. The type-specimen, natural size, showing the anterior and posterior clefts and the tine, concentric stria-. Fig. 21. The same enlarged to three diameters, showing the characters more distinctly. Chemung group. Dansvilh . Livingston county. Fig. •!■!. A. portion of the body-whorl of Gfoniatites sinuosus, which encloses a small body, bearing some- what the proportions of the preceding sj imen, but differing from it in the shorter anterior and posterior clefts, the pair of nodes at the anterior extremity, and from all the species of Dis- cinocaridcB inthe absence of concentric striae upon the surface. Of all the forms here illus- trated this is the only example which has 1 n observed in close association with any species of cephalopoda. 1-" i tr . 23. The body in question enlarged to three diameters. Portage group. Naples, Ontario county. DlPTEROCARIS FENN-E-D-SDALI. Page 'J00. Fig. 24. The type specimen of this species, showing the left ala of the carapace. The remainder of the carapace is restored in outline, indicating the relative proportions of the anterior and posterior clefts. Portage group. Canadice, Ontario county. DlPTEROCARIS PROCNE. Page 201. Fig. 25. The left ala of the carapace in a flattened condition, the right ala being restored in outline. Portage group. Canadice, Ontario county. Pig. 26. The entire carapace normally folded, showing the character of the anterior and posterior clefts. Fig. 27. The same in profile, showing the convexity of the carapace. Chemung group. SasMnsville, Steuben county. Palaeontology of NYyoIVII. (LLM.VAhl.Mi.K & DISOXOI MUDJF, i *■ ; 1 IV 18 19 3. >' • /""' # 2£ '' ■ - ft ^ fP l PLATE XXXVI. TlTRRILEPAS FLEXUOSI g. Page 215. Wig, 1. A. single minute plate, enlarged to ten diameters, showing the broad, sinuous median depression and the lamellose lines of growth. Near the apex of the plate the median depression b< mes obsolete and the growth lines more doselj crowded and ti'ansverse. Corniferous limestone. Canandaigua, Ontario county. TURRILEPAS CAXCKI.LATUS. Page -216. Fif. 2. A single plate enlarged t" ten diameters, showing the distant, elevated, concentric lines of growth, and the elevated, interrupted radiating lines. Corniferous limestone. Canandaigua, Ontario county. Tuiuui.epas Devonicus. Page 216. Pig. 3. A plate of this species enlarged to six diameters, showing the median ridge an. I the plumose appearance of the surface, produced by the closely disposed tines "I growth, Hamilton group. Canandaigua. Ontario county. TURRILEPAS NITIDUHs. Page 218. Fig 4. A single plate, enlarged to six diameters, showing the very tine concentric stria- which become obsolete along the faint median depression, the posterior surface being smooth and ornamented with transversely parallel rows of conspicuous perforations. The apex of the plate is restored in outline. Hamilton group. Canandaigua, Ontario county. TURRILEPAS SQUAMA. Page 217 Fig. 5. A plate referred to this species, enlarged to four diameters, showing the deep deflection along the anterior margin, the regular and closely crowded concentric stria3, and the absence of a median depression. Hamilton group. Canandaigua, Ontario county. Fig 6. A vatve fenestree referred to this species, enlarged to four diameters. The nucleus is sub-apical, and the concentric stria' are somewhat more distant than in the associated plates of the species. Hamilton group. Canandaigua, Ontario county. Fig. 7. A portion of an unusually large plate, enlarged to four diameters. Hamilton group. Canandaigua, Ontario county. Fig. 8. A valve fenestree. enlarged to four diameters, showing the sub-apical nucleus and the tine, closely crowded concentric stria1. Hamilton group. Canandaigua, Ontario county. TURRILEPAS TENER. Page 219. Fig. 9. A fragment of shale, showing the natural size of nine scattered plates referred to this species. Hamilton group. Canandaigua, Ontario county. Figs. 10, 11, 12, 13. Single plates taken from the group represented in the preceding figure, each enlarged to six diameters. Hamilton group. Canandaigua, Ontario county. Fig. 14. A smaller plate, also enlarged to six diameters, upon which the growth lines are more prominent and more distant than in the other specimens figured. Hamilton group. Canandaigua Lake. TURRILEPAS FOLIATUS. Page 218. Fig. 15. A single, somewhat imperfect plate, enlarged to four diameters. The outline of this plate is different from that observed in any other species, but its substance and surface markings are of similar character, and it is probably correctly referred to the same group of animals. Hamilton group. Canandaigua, Ontario county. PLATE XXXVI— Continued. TURRILEPAS (?) NeWBERRYI. Page 219. Fig. 16. Two valves of this species in an uncompressed condition, natural size. The upper and more per- fect specimen has a rounded dorsum, the unrepresented side being of the same character as that which is shown. There also appears to lie evidence of a cleft extending from the apex to the anterior margin, as in Spathiocaris. Plates of this character are distinctly different from the others here represented under the term Turrilepas. Cleveland shal^ (Chemung group). Birmingham, Erit county, Ohio. Pig. 17. A large plate, natural size, showing the concentric surface markings, and a broad postero-lateral depression. This plate has the same outline as one side of the plates lepresented in the last figure ; it is, however, impossible to determine from the specimen whether or not the plate was folded along the dorsal line. Cleveland shale (Chemung group). Sheffield, Erie county, Ohio. Fig. IS. A smaller plate, natural size, showing a different form and more closely crowded growth-lines. Cleveland shale (Chemung group). Sheffield, Erie county, Ohio. Fig. 19. A small plate having an outline similar to that represented in figure 17. Cleveland shale (Chemung group). Sheffield, Eric county, Ohio, The illustrations of this species have been drawn from the type specimens. Strobilepis SPINIGERA. Page 212. Fig. 20. A nearly entire capitulum, in which the parts retain somewhat of their proper arrangement. The conical terminal plate is overlapped at its edges by three vertical ranges of plates, those of the left range lying in juxtaposition, while those of the right range have been considerably dis- placed. Of the axial range of smaller plates, three are shown in place, and a fourth plate of this range lies beneath the edge of the fourth plate of the left range. The range of spines has been pushed from its normal position around to the right, and the lower members of the row have been displaced. These spines were probably symmetrical in position with the axial row of plates. The specimen is enlarged to one and a half diameters. Pig, 21. The last three spines of the undetached portion of the row, enlarged to two diameters. These spines are numerically the ninth, tenth and eleventh ; the first two, like all those preceding them, bear a deep ami conspicuous groove for nearly their entire length, while the eleventh and all those following, appear to have been inverted, showing a convex surface with a sharp axial carina, the lateral slopes being more or less incurved. Fig. 22. An enlargement of a portion of the surface of one of the plates, showing their punctate structure, the quincunx arrangement, the oblique direction of the punctae, and. tfye concentric lines pro- duced by the excavation of the shell about the aperture of each puncta. Hamilton group. Menteth's Point, Canandaigua Lake. Pro tobalan us Hamiltonensis. Page 209. Fig. 23. The type specimen enlarged to fifteen diameters. This has been somewhat broken over the pos- terior portion, but shows the composition of the capitulum, its twelve discrete plates, consisting of the carina, rostrum and live pairs of latcralia, the radiating ridges upon the surface of these plates and the smooth radial areas. On the right side the peripheral portion of the shell has been somewhat flattened. Hamilton group. In the Marcclhis shales at Avon, Livingston county. PaLjEOCREUSIA Devonica. Page 2f0. Fig. 24. A view of the type specimen, natural size, showing the capitulum, the remainder of the shell being imbedded in' a colony of Favosites 1/emisphericus. Fig, 25. A constructive representation of the profile of this specimen, showing the long, tubular basis sur- rounded by cell tubes, and the elevation of the capitulum. Fig. 2i'>. The same view of the specimen as that presented in figure 2-1, enlarged to two diameters. The alum has 1. i encroached upon by the walls of the cell tubes, which have apparently ex- tended as far as tie- aperture, and subsequently been broken away. The surface of the plate shows faint radiating stria', and a single furrow concentric with the margin. The aperture appears somewhal too large on account of the slight imperfection of its anterior margin. Corniferous limestone. LeRoy, Genessee county. I I.KI'AIM tl I. & I \l \M i . 1 Palaeontology oi N YyoIVIL I 24 '•mm' 23 25 ^ ^Wi-a^*ti^ '■ . {*' •»£"-., : I I p - S U P P L E M E X T PLATE CXIV. Tentaculites minutus. Hall. Page j. Fig. 1. An imperfect individual, enlarged to six diameters, and showing verj faint longitudinal strise, Clinton group. Rochester, Monroe county. Fig. 2. Two entire individuals of the same species, similarly enlarged, showing the regular equidistanl annuli and the tine annulations. Clinton group. Rochester, Monroe county-. Tentaculites Niagarensis, Hull, var. Cumberland^*:, n. var. Page 5. Figs. 3, 4, 5. Entire specimens, enlarged to six diameters, showing the slender, very terete form, the con- spicuous, evenly rounded, irregularly distant annuli, and the tine, sharp interstitial annulations. The surface ornamentation is very similar to that of T. Niagarensis, but the annulations are much more conspicuous than in that species. Niagara group. Cumberland, Maryland. Fig. 6. A portion of another individual of this species, enlarged to nine diameters. Niagara group. Cumberland, Maryland. Tentaculites gyracaxthus. Eaton. Page 5. Figs. 7, 8 and 9. Individuals of this species, enlarged to six diameters, showing the great variation in tin- intervals between the annuli. The ornamentation of thisspecies, though similar to that of T. Niagarensis, var. CumberlandiCB, is subject to greater variation, and the shell is stouter than in that variety. In figure 9, the shorter specimen has been flattened and made to appear rela- tively too broad. Lower Helderberg group (Tentaculite limestone). Scho/iarie, Schoharie county. Fig. 10. k block of the Tentaculite limestone, showing the abundance of these individuals and the varia- tion in their surface ornamentation. Lower Helderberg group. Schoharie, Schoharie county. Fig. 11. Two large anil somewhat flattened specimens referred with doubt to the same species. Lower Helderberg group (Tentaculite limestone). Jerusalem Hill, Herkimer county. Figs. 12 and 13. Longitudinal sections of individuals, enlarged to six diameters, showing the thinness of the shell, and the invagination of one shell within another. This is not an infrequent mode of occurrence in this formation where the rock is sometimes almost wholly made up of these bodies. In the specimens figured the annulations are unusually regular and closely set. Lower Helderberg group (Tentaculite limestone). Schoharie, Schoharie county. Tentaculites elongatus. Hall. Page fi. Fig. 14. An individual of this species, natural size, from which a portion of the shell has been broken, showing an apparently septate structure near the apex of the internal cavity, which is probably due to successive depositions of the tilling matter. Lower Helderberg group. Schoharie ? Scluiharie county. Tentaculites acula. n. sp. Page 6. Fig. 15. An individual of this species, natural size. Fig. 16. The same, enlarged to five diameters, showing the regularity of tin' annuli and the comparatively few annulations on the intervals. Lower Helderberg group. Port Jervis, Orange county. Fig. 17. A larger individual of the same species, from which a portion of the shell has been broken, showing its thickness. Enlarged to six diameters. Lower Helderberg group. Port Jervis, Orange county. (PLATE CXIV— Continued. TeNTACULITES DEXITHEA, 11. S[). l'age 6. Fie. Is- Three individuals of the species upon a block of sandstone. Fig-. 19. The si imen on the right of the block in the, preceding figure, enlarged to two diameters. The upper portion of the | n is preserved as a cast of the interior, the lower portion retaining tin- crust. Tli'- species differs from T. scalarifoi mis in its much more elongate and slender form anil its more sloping annuli. Upper Helderberg group. From the sandstones at. the base of tin ('< rnift runs Hun stone at Pendleton, Indiana. Tentaculites scalariformis. Hull. Page 6. Fig. 20, A block of limestone bearing numerous individuals of this S] tes* all of which are flattened and consequently made to appeal' relatively too broad. Comiferpus limestone. Delaware, Delawap counpy, <>hio. Hyolithes centennialis. Barrett. Page 6. Fig. 21. A fragment of a small specimen of this species which was intended to represent the ventral side of the shell, but the left edge of the drawing isthe axial line of the convex or dorsal surface, and the surface represented is the right dorsal slope. The specimen shows the faint longitudinal stria' near the lateral margin. Lower Helderberg group. Port Jerris, Orange county. Fig. 22. Dorsal view of a large individual, showing the character .of the ornamentation, which consists of elevated, transverse, sinuous lines. 1 ing obsolete near margins. The edges of these striae are sometimes faintly crenulate. Fig. 23. A portion of the surface of another specimen enlarged to two diameters, showing the crenulation of the' transverse striae. Lower Helderberg group. Port Juris, Orange county. Hyolithes iieros, n. sp: Page 7. Fig. 24. The ventral surface of a specimen from which the apical portion has been lost, showing the faint tranverse lines and two longitudinal furrows which extend nearly two-thirds the entire length of the shell. Fig. 2f>. The dorsal surface of the same specimen, showing the fine longitudinal striae and the broad mar- ginal undulations. Fig. 26. A portion of the dorsal surface, enlarged to two diameters, showing the character of the orna- mentation. Fig. 27. Transverse section of the same specimen, showing the degree of convexity of the dorsal and ventral surfaces. Lower Helderberg group. Near Clarksville., Albany county, Styliola spica, n. sp. Page 7. Fig. 28. An individual enlarged to two diameters, showing the symmetrical uncompressed form and smooth surface. This s] ies differs from (ityliulit Jissurilia in its comparatively great size, and the entire absence of indications of transverse annuli. Hamilton group. Hamburgh, Erie county. COLEOLUS IlERZERI, 11. Sp. Page 7. Fig. 29. A nearly entire individual showing the gently incurved form and the faint obliquely transverse striae. Waverlj group. Medina, Ohio. 1'llARETRELLA TEXEHROSA, II. Sp. Page 7. Fig. 30. An individual of tins species', showing the Hyolithes-like form and the tine, sinuous, transverse striae, 'lie- substance of the shell is extremely thin and delicate and the stria? are slightly imbricating. Fig. 31. A portion el the surface of the same specimen enlarged to two diameters, showing the character of tl rnamentation. Hamilton group (Genesee shales). Genesee county. palaeontology of NY, Vol.V.Pt.II Suppieme I'teropoda plate ) rtiuAsunri. PLATE CXV. Tubicolak Annelida of the Hudson River Group Cornulites ; in various stages of development. Pagtia 8 18. Fig. 1. A portion of the surface of a much macerated Orthoceras, showing tl artiest stages of growth observed; Fig. 2. The same specimen, enlarged to three diameters, the relative distances between Hi" tubes being diminished in the drawing. The tubes show every variation in form, from the completely en- rolled helicoidal condition, suggestive of Spirorbis, to the partially enrolled or serpuloid stage, and to theinore elongate, sinuous form characteristic of Cornulites. The Spirorbis dm iwnati cn.iia. Miller and Dyer, probably represents the earliest or coiled condition of these bodies In the smallest examples here illustrated the surface is entirely smooth, but with advancing growth becomes first faintly and then more strongly annulated. The largest of the speci ns also show faint longitudinal strias. In these latter tubes the embryonal tips have been broken off. Hudson River group. Cincinnati. Ohio. Fig. 8. Tubes in about the same condition of growth as those described in the preceding specimen, en- larged to three diameters, showing the distinct transverse annulations. The tubes are all attached for their entire length to a valve of Strepto rhynchus plano-convt tus. This is ths stage of development represented by the species Ortonia minor, Nicholson. Hudson River group. Cincinnati, Ohio. Fig. 4. A. fragment of Monticulipora. bearing numerous tubes in the Serpuloid condition represented in fig. '-!. Each of those tubes is finely but distinctly annulated, but the longitudinal stria' are but partially developed. Enlarged to three diameters. Hudson River group. Cincinnati, Ohio. Fig. 5. A single, slightly Hexuous tube, natural size, with strong, somewhat irregular annulations and very fine longitudinal strife. This is the condition of growth represented by the species Tentaculites St< rlinr/i nsis of Meek and Worthen. Hudson River group. Cincinnati, Ohio. Fig. 6. The same stage of growth exhibited by three tubes attached to one another and, at their bases, to a fragment of a crinoidal stem. Fig. 7. The same, enlarged to three diameters, showing the longitudinal stria'. Hudson River group. Cincinnati, Ohio. Fig. 8. Three tubes of somewhat larger size and more flexuous form, attached to a crinoidal [fragment. These specimens show an increasing irregularity in the annulations. Hudson River group. Cincinnati, Ohio. Fig. 9. An isolated group of similar tubes, attached to one another for their entire length and growing upon the fragment of a crinoidal column. ' Natural size. Fig. 10. The opposite side of the same specimen. Hudson River group. Cincinnati. Ohio. Fig. 11. A group of adnascent tubes attached to a valve of Strophomena atternata. Hudson River group. Cincinnati, Ohio. Pig. 12. Two larger tubes attached to a single crinoidal segment. In this form the annulations have be- come more, irregular and obsolescent, and the longitudinal stria? much more conspicuous. Hudson River group. Cincinnati, Ohio. Fig. 13. Two adnascent tubes in which the annulations are extremely irregular, and have l> )me obsolescent. Hudson River group. Cincinnati, Ohio. Fig. 14. A group of smaller tubes, showing the increasing irregularity and obsolescence of the annulations'. Hudson River group. Cincinnati, Ohio. Fig. 15. A. large tube, having a surface of similar character to that represented in the last three figures. Enlarged to two diameters. Fig. 16. A longitudinal section through the same specimen, showing the dense cellular wall and the folds on the internal surface, corresponding to the external annulations. Hudson River group. Cincinnati, Ohio. Fig. 17. A group of simple tubes in a very early stage of development, having a common point of attach- ment and a radiating habit of growth. Hudson River group. Cincinnati, Ohio. Fig. 18. The under or basal side of a sificified specimen, affording a more perfect illustration of this i ]o of growth. The outer walls of the tubes where shown are distinctly annulated. Fig. 19. The upper surface of the same specimen, showing the apertures of the] connate tubes, the entire colony presenting a strikingly favositoid appearance. Fig. 20. The view represented in fig. 8, enlarged to three diameters, Hudson River group. Cincinnati, Ohio. Fig. 21. Basal view of a similar specimen, in a somewhat more advanced stage of growth, showing the point of attachment and the annulated surfaces of the tubes. FiS. 22. The upper surface of the same specimen. Fig. 23. The same, enlarged to three diameters, showing the apertures and concentrically annulated inter- nal surface of the tubes. Hudson River group. Cincinnati, Ohio. I'T.ATE CXV— Continue!. Fig. 24. A later stage in the development of the tubes, exhibiting the same mode of growth. In this speci- men tin- invynkir aminl.il wn- :in yonnger colony attached usay the apices of the' larger tubes. Hudson River group. Gineinmati p len in the species Ortonia eo tiicff, Nicholson, and Conchieol.ites copruoatnis, Nicholson; Nielsen Rivergironp. Ginevnnati, Ohio* Fig. 28. A stage of growth in which the tubes are gently Bexuous and mostly free the annulations quite regular and the longitudinal strite distinct. This is a condition directly comparable to that ,-,.],, ,i figures •">. 6 and 7. and has been described by Mr. S. A. Miller, under the name Tentaculites Richmondewds. The same or a closely similar condition of development is repre- sented b i'es Tentaculites tenuist/riatmSi Meek and Worthen,; Hudson Rivei'^group. Richmond, Indiana Fig. -"■'. Another specimen representing the same stage of development. Hudson River group. Rtehmmtd, Indiana. Fig. 30. A th ii-il -| ecimen.enlarged to three diameters, sb >wing more distinctly the character of the surface ni.i rkings. Hudson River group. Richmond, Indiana. Fig. 31. To hes in a condition of growth eloselj similar to that of the preceding specimens, the annulations being somew hat less regular This is lie- 35 ntaenlites hit urwu) el' Shumard, page IS. Hudson River group. Arefl»YK?api GrirardeaM, Missouri- Fig. 32. A longitudinal secti f the tul I ites SterUngensiSrMpek. ami Wet-then, enlarged to five diameters, showing the.thicknesS of the, walls. Hudson River group. Cincinnati, Ohio. Fig. 33. Longitudinal sections of two adnascent tubes similar to those represented in figures 9 and 10. enlarged to three diameters showing the thickness of the walls. Hudson River group GiiuAnnati, <>h'it>. Fig. Ml. Longitudinal sections of portions of two .similar tidies, enlarged to three diameters, showing thicker and coarsely cellular walls Hudson River-group. Cincinnati, Ohio. Fig. 35. A small specimen of the Tentaculites Riahmwkdensis, Miller, showing the thick walls. The appar- ent transverse septa are the edges of the internal annulations, Enlarged to three diameters. Hudson River group. Richmond, Indiana. Fig :3ri. A longitudinal section of the Tentacnlites Riehimmdensis, Miller, enlarged to six diameters, show- ing the cellular structure of the thick wall. Hudson Riveit group. Richmond, Indiatut, Fig. :i7 A longitudinal section of the same form of growth, enlarged to live diameters. Hudson River group. Richmond, Indiana. Fig. 3S. Longitudinal Bectiohs of two individuals of the Tentaculites Richnymdensis, Miller, enlarged to tin- liameters, showing the thickness of the walls. Hudson River group. RiChmo7id, Indiana Fig. 39. Sections of tubes in a similar stage of development, enlarged to three diameters. The apparent septate character of the apical portion of the longer tube is due to successive depositions of the calcareous tilline;. Hudson River group. Richmond, Indiana. Fig. t:s. A broken tube attached tea valveiof Streptrohyiichusplano-conyexus, showing the annulations on the nine,- surl'.-e-e of tlie wall, which give an apparent septate character to the tube. Hudson River group. ' "nn ■■inn/iti. Ohio. CoiiXl t.ITES IMMATt'KLJS. Page 18. Fig. 40. Tubes in a verj eat l.\ si rpuloid sttige of development, similar to that represented in figs. 2 and 4, attached to the surface of Orthoceras. Utica slate. Hdlland Patent, Oneidacounty. CoRNULITES FLEXUOSUS. Page IS. Fig. 41. The original sj imen of Tentaculites ? fiexuosus, Hall, exhibiting a diffusely radiating mode of growth, the character of the tubes being similar to that represented in figures 9, 10 and 11, the tubes being more slender and proportionally mere elongate. The individuals tire attached to a valve of Stropho7nena alternata. Enlarged to 'v. < diameters. Treuton limestone. Lowville, Lewis county. Fig 12, A ingle tube of this form, enlarged to two diameter arid retaining the embryonal tip. Trenton limestone Lowville, Lewis-county. tkkxtox ik urnsox uiyki: uhoits . Supplem phi .1 ry to the I '■ PLATE CXVI. CORNULITES PROPRIUS. Hall, l'age 19. Fig. 1. A single young individual attached to the shell of Slrophostylus cyclostomus. The transverse an- notations are very conspicuous, but the longitudinal striae are scarcely developed. Fig. 2. A group ef three individuals in the same stay.- of development, attached to the shell of Platyostoma Niagan asi . Fig. 3. A group of young individuals attached to a gastropod shell and exhibiting an irregular]} circular arrangement in their mode of growth. Fig. 4. A young individual attached for its entire length to a branch of Trematopora. Fig. 5. A later stage of growth, in. which the transverse annulations are less regular and the longitudinal stria: distinctly visible. This tube is attached to a fragment of Idehenalia, and retains its in- curved apical portion. Fig. 6. A specimen in a similar stage of growth, also retaining the apical porti f the tube. Fig. 7. A somewhat crushed individual attached to the shell of Rhyncfumella Stricklandi. Fig. 8. Two large tubes attached by their apices to a shell of Platystoma Niagarense, leaving the bodj of the tube nearly free. In this stage of development the annulations are obsolescent and less regular, and the longitudinal stria- conspicuous. The terminal portion of left tube is restored in the drawing. Fig. 9. A somewhat larger individual attached to the calyx of Eticalyptocriniis erassus. The attached portion of the tube is flattened and united 1>\ nearly its entire width to the crinoidal plates. The annulations are obsolete. Fig. 10. A very large individual, showing the characters of the fully developed form, in which the annula- tions have become very irregular and obsolescent, and the longitudinal stria- correspondingly prominent. Fig. 11. A somewhat crushed specimen, showing very irregular growth, a strongly striated surface, and the repair of injuries received during the life of the animal. Fig. 12. Another specimen, showing similar characters. Fig. 13. An enlargement of the surface of the last .specimen, showing the character of the longitudinal stria' and the abrupt change at one of the concentric ridges. Fig. 14. An enlarged longitudinal section of a young tube, in which the annulations are well developed J showing the thickness of the" vesicular wall. Fig. 15. A longitudinal section of a larger individual, natural size, showing the thickness of the vesicular wall and the annular ridges of the internal surface. Fig. 16. A longitudinal section of a large tube, in which the vesicular wall is quite thin, and the inner surface strongly annulated. Fig. 17. A longitudinal section of a large tube, the vesicular walls of which are verj thick. Fig. 18. An enlargement of a pertion of the left wall, represented in tig. 17. showing more distinctly the vesicular structure of the walls and the formation of a layer of vesicular tissue over the annu- lations of the internal surface. Fig. 19. A transverse section of a tulie. natural size, showing the thickness of the walls. On the upper margin, and on the right hand lower margin are intervals where the cellular tissue has not been developed. Fig. 20. A similar transverse section, enlarged. Fig. 21. A still greater enlargement from the same specimen. tThe specimens illustrated in the preceding figures 1-21 are all from the Niagara group. Waldron, Indiana. Cornulites Clintoni. Hall. Page 18. Fig. 22. An internal cast of a tube, showing impressions of the strong annulations upon the inner surface. Clinton group. Near Lockport, Niagara county. PLATE CXVI— Continued. CORNULITES DISTANS. Hall. Page 18. , Fig. 23. An enlarged individual, showing the slightly llexuous form of the tube, and the distant, regular annulations. Clinton group. Rochester, Monroe county. CORNULITES, Sp. ? rage 19. Fig. 24. A portion of an individual enlarged, doubtfully referred to this species, showing the strong annu- lations and the smooth interspaces. Fig. 25. Lateral view of the same specimen, showing that the tube is narrower in one diameter than in the other. Clinton group. Near Lockport, Niagara county. CORNULITES CHRYSALIS, 11. sp. Page 20. Fig. 26. An individual enlarged, in which the annulations are very regular and present the appearance of a series of closely set, inverted and ensheathed cones. Lower Helderberg group. Locality doubtful. Fig. 27. A much enlarged example, showing more distinctly the features exhibited in preceding figure. Lower Helderberg group. Locality doubtful. Fig. 2S. A very small tube, enlarged to ten diameters, attached for its entire length to a branch of Trema- topora regularis. The form is slightly fiexuous and the annulations nearly obsolete. Lower Helderberg group. Near Cldrksmlle, Albany county. CORNULITES CINGULATUS, 11. Sp. Page 20. Fig. 29. A small fiexuous tube, enlarged, showing the unequally distant annulations which are sharply angled toward the aperture but evenly rounded toward the apex. Lower Helderberg group. Locality doubtful. CORNULITES TRIBULIS, 11. S|>. •Page 20. Fig. 30. Two individuals of this species, growing in an aduascent condition, enlarged to three diameters, showing the low irregular annulations and the fine longitudinal striae. Hamilton group. Sopewell, Ontario county. CORNULITES INCURVUS. Page 18. See Plate 115, fig. 31. Fig. 31. A fragment of rock, showing several tubes of this species, natural size. BalacOl Supplement Supplementary lo 1 1 > 4 Picropocio PLATE CXVIa. CORNULITES SERPULARIUS. Page 21 Fig. 1. (= f. 5, Sow., loc. cit.)* A. [Brachiopod (Athyris?) having two young: individuals of the fossil attached to its surface throughout their entire length. Fig. 2. (= f. 5a, Sow., loc. cit.) A group of three individuals in the young stale, attached for their entire length to the shell of a Brachiopod 1 Fig. 3. (= f. 6, Sow., loc. cit.) A groupof two adnascent individuals in an advanced stage of growth, show- ing them to be composed of successive rings, as described in the text. The sin fare has been cut or worn so as to expose the interior cavity. Fig. 4. (= f. 7, Sow., loc. cit.) The distal or free portion of a tube, the upper portion of which is dis- tinctly striate,!, while the test has been partially removed, showing the interior rings or cups ; the cast of the interior. Fig. 5. (f. = 8, Sow., loc. cit.) A more mature example, preserving the curved initial extremity. The test has been partially removed by weathering or maceration. Fig. 6. (f. = [8], Sow., loc. cit.) A larger individual, in a similar condition to the preceding, wanting the the initial extremity. Fig. 7. (f. = 8, Sow., loc. cit.) A longitudinal section of a tube, showing, on the inner side, the project- ing edges of the successive rings, and the incipient and developed tissue of the walls. Fig. 8. (f. = 9, Sow., loc. cit.) A portion of a mature tube partially exfoliated, showing the vesicular structure on the right side, with the external striated test upon the upper left-hand side. CORNULITES ARCUATUS. Page 19. Fig. 9. Cornulites areuatus, Conrad. Jour. Acad. Nat. Sci., vol. viii, p. 276, [pi. xvii, fig. S. 1842. (A copy of Mr. Conrad's figure.) Near Albion (Wayne county, in error), N. Y. From the Niagara limestone. Cornulites Clinton i. Page 18. Corrected from C. flexuosus (Pal. N. Y., vol. ii, p. 98) in Twenty-eighth Kept. N. Y. State Mns. Nat. Hist, p. 184. 1879. Fig. 10. (Fig. 12a, vol. ii, loc. cit.) A mature example, preserving the initial point, and the test, which has been somewhat macerated. Fig. 11. (Fig. 12c, vol. ii, loc. cit.) A cast of the interior of a large individual, where the initial point is wanting. Cornulites bellastriatus, n. sp. Page 20. Cornulites , Pal. N. Y., vol. ii, p. 353, pi. lxxxv, figs. 15 and lt>. Fig. 12. An adult specimen, imperfect toward the base, preserving the test and showing the transverse and longitudinal strise with obsolescent ann illations. Fig. 13. An adult, nearly entire individual, preserving the striated test with distinct annulations. The specimen is compressed toward the outer extremity. * The figures are reversed from the position given by Mr. Sowerby, in order to have them conform to the illustrations on plates cxv and cxvi, and in accordance with their natural position or mode of growth from the narrow apex to the aperture. PLATE CXVI a— Continued. CORNULITES MAJOR, Biirnillde. Fig. 14. An individual imbedded or adhering to some foreign body for its entire length. The several figures under other names given by Barrande may be immature stages of the same species. The following illustrations are given by Mr. Nicholson, in his paper on " Ortonia, a New Genus of Fossil Tubicolar Annelides," etc. Geol. Mag., vol. ix, p. 447. 1872 : ORTONIA CONICA. Page 23. Fig. 15. (Fig. 1 — A.) Tubes of Ortonia eoniea, Nieh., growing upon the valve of Stmphomena alternata, natural size. Fig. 16. (Fig. B.) A single tube of the same, enlarged. Th& following illustrations arc given by Mr. Nicholson, in his " Description of Two New Species of Fossil Tubicolar Annelides." Geol. Mag., vol. x. pp. 54-57, pi. iv, figs. 2, 3. 1873 : CONCHICOLITES CoRRUGATls. Page 23. Fig. 17. (Fig. 2 a,*) [= fig. 3 on plate]. "A group of the tubes of Conchieolites corrugatus, growing upon Pleurotomaria bilix, natural ^ize." Fig. 18. ( — b,) [= fig. 3a of plate]. "A single tube of the same, enlarged." ORTONIA MINOR. Page 24. Fig. 19. (Fig. 3 — a,) [= 2a of plate]. "Tubes of Ortonia minor, Nich., growing upon a Strophomena, natural size." Fig. 20. ( — b.) [= 2a on plate]. "One of the tubes, enlarged." * The references to figures of plate iv, Geol. Mag., p. 57, are reversed in the explanation. SJaSUSOSff ^U^ELiL U^LliTj'iM vruVFViV;u\ Sii]i|ili-iu< iit.irv In Ihr I'u i opocli Paleontology of N.Y.Tol V . R.ff. Supplemei a/ia w \j- P ' ! i - ^ 1 ,s '•J- - 9 : •r~ PLATE CXVII. Orthoceras duramen. Page 25. Fig. 1. >A septate fragment, showing- the rapid enlargement of the tube, and the depth of the air-chambers. Schoharie grit. Clarksville, N. Y. Orthoceras sceptrum. Page 26. Fig. '2. An individual preserving a large portion of the chamber of habitation and about thirty air-cham- bers. The specimen is an internal mould and shows an organic deposit in the air-chambers toward the apex where the walls have been dissolved. The organic deposit is represented by concavities in the filling of the air-chambers and increases in amount toward the apex. The marked curvature of the tube is apparently normal and not the result of compression. Upper Helderberg limestone. Cherry Valley, N. Y. Trochoceras (Gonioceras?) pandum. Page 37. Fig. 3. A specimen preserving ten air-chambers, showing four very shallow chambers at the larger ex- tremity and probably close to the chamber of habitation. Fig. 4. Id. Section showing the lentiform transverse section of the tube. Fig. 5. The apical portion of an individual, showing the enlargement of the tube and the. shallow air- chambers toward the apex, as mentioned in the description of the species. Schoharie grit. Albany county, N. Y. Orthoceras directum. Page 27. Fig. 6. An example preserving a large part of the chamber of habitation with twelve attached air-cham- bers. The suture lines are deeply impressed from weathering and the solution of the septal margins. F'ig. 7. Id. Longitudinal sections, showing the septa to have been broken down and obliterated on the interior of the tube, notwithstanding the marked indications of septa shown on the exterior of the specimen. Corniferous limestone. Delaware, Delaware county. 0. PLATE CXVIII. Okthoceras rudens. Page 28. Fig. 1. A j >< >t-t i • pi : of the chamber of habitation, showing the numerous regular annulations of the tube and the longitudinal stria1 of the test. Hamilton group? Livingston county, N. Y. Okthoceras expositum. Page 29. Fig. 2. An imperfect individual preserving1 the greater part of the chambered portion of the tube, and portion of the chamber of habitation. Iron ore bed of the Chemung group. Canton, Bradford county, Pennsylvania. Orthoceras consortale. Page 29. Kig. '3. The air-chambers and lower portion of the chamber of habitation, showing the enlargement of the tube and the depth of the air-chambers. Some traces of the surface markings are pre- served on different parts of the tube. Pig. 4. Id. A natural longitudinal section of five air-chambers, showing the monilifonn sipluincle and the rays on the upper bead at its contract with the septum. Fig. a. Id. A septum showing the pnsiti.ui of the siphuncle, and exhibiting the effects of a slight com- pression of the tube. Chemung group. Near Panama, Chautauqua county, N. Y. Orthoceras Indianensis. Page 30. Fig. ti. A longitudinal section of three air-chambers, showing the small passage made by the siphuncle through the septa, and the reflection of the margin indicating a moniliform siphuncle. Fig. 7. A fragment showing the enlargement of the tube, and depth of the air-chambers. Fig. 8. The chamber of habitation showing its extent, and a broad constriction near the aperture. Fig. 9. Id. The last septum showing the position of the siphuncle. Fig. 10. A fragment showing the characters of the r.rganic deposit on the walls of the air-chambers and septa. Goniatite limestone. Rockford, Indiana. Orthoceras Icarus. Page 31. Fig. 11. The chamber of habitation with four attached air-chambers, showing the form of the tube and tie- depth of the chambers. Fig-. 12. Id. Septum showing the position of the siphuncle, and the circular transverse section of the tube. Fig. 13. Longitudinal section of a chambered fragment showing the passage for the siphuncle through the septa. Fig. 14. An enlargement to two diameters of the interna] mould of a small imperfect specimen, to show the concave walls of the air-chambers from the solution of an organic deposit, and a line of nodes indicating the ventral side of the tube. Kig. 15. A septum of another individual enlarged two diameters, showing an elevated areola with a fur- rowed margin surrounding the siphuncle. produced by the solution of the organic deposit on the septum. ^ Goniatite^limestone. Rockford, Indiana. TfrAaflTLTT.TCT D JEKEfcTflST© KlDf Supplement PLATE CXIX. GOMPHOCERAS MITRA. Page 32. An internal mould of a large nearly entire individual, showing the essential features of the species. The figure is a dorsal view of the specimen and shows the broad flat margin of the large aperture. Corniferous limestone. Lexington, Scott county, Indiana. T'l'l'-: ~€MR£l ■ • ntolor Supplement : '■■:*■■ ■' - ■ s. • - PLATE CXX. GOMPHOCERAS EXIMIUM. Page 32. See Plate 121. Fig. 1. An outline representing' the size and form of a large individual, showing the point of greatest gibbositj and the frequency of the septa. Pig. -'. Longitudinal section of a fragment showing the nummuloid siphuncle and the septa. Many of the septa have been removed by the process of maceration before being imbedded, and the course of the siphuncle toward the apex is indicated by a discoloration of the tilling of the air- chambers. In the upper porlion of the siphuncle, at the extremities of the cusps where the tube penetrates the septa, are seen several indications of an organic deposit, or a thickening of the walls of the siphuncle. Fig. ;i. /(/. The end of the siphuncle showing the radiate appearance of the deposit mentioned under the preceding figure. Upper Helderberg limestone. Columbus, Ohio. GOMPHOCERAS IMPAR. Page 32. See Plate 121a. Fig. 4. View of the specimen described, preserving the chamber of habitation and a portion of seventeen air-chambers. The tube shows three constrictions or undulations which apparently represent a normal condition of growth. Upper Helderberg limestone. Columbus, Ohio. GOMPHOCERAS NASUTUM. Page 34. See Plate 121. Fig. 5. Ventral view, showing the form of the chamber of habitation, and the sinus and reflection of the margin, forming the small aperture. Traces of the crenulated zone are shown at the base of the grand chamber where the tube suddenly contracts forming a shoulder at its junction with the septate portion. Fig. 6. Id. View of the aperture, showing its broad elliptical form and the sinus in the margin corres- ponding to the ventral or small aperture. Fig, 7. Id. Transverse section representing the position and size of the siphuncle. Chemung group. Belmont, Allegany county, N. T. m n - ■ - PLATE CXXI. GoMPHOCERAS EXIM1UM. Page 32. See Plate 120. Fiy. 1. Ventral view of a medium sized specimen, retaining' the test over the whole exterior of the tube, and showing the form of the shell and the broad gentle sinus in the lines of growth, indicating the position of the siphunele. Corniferous limestone. Columbus, Ohio. Pig. 2. A fragment of the septate portion, in which the siphunele has been partially uncovered by the removal of a portion of the filling of the air-chambers. GOMPHOCERAS MITRA. Page Z'i. See plate 120. Fig. 'S. A large septate fragment with the siphunele as exposed in the process of weathering of the air- chambers, showing the moniliform character of the siphunele, and the furrowed cinctures of its tube. Corniferous limestone. Columbus, Ohio. 'JtPIPL^ji LLflElIiLUlE'i i — i - . Supple PLATE CXXIa. GOMPHOCERAS IMPAE. Hall. Page 32. See Plate 120. Fig. I . Ventral view of an individual preserving the chamber of habitation and a large part of the septate tube, sin. winy the characters of the siphuncle as exposed in the process of weathering-. Near the grand chamber, there were several very shallow air-chambers, as indicated by the beads of the siphuncle. Corniferous limestone. Colwmbus, Ohio. GOMPHOCERAS CRENATUM. Page 33. Fig. 2. Lateral view of the fragment, showing the form of the tube, and the furrows of the crenulated band, which are continued over the walls of the air-chambers. Corniferous limestone. Delaware county, Ohio. GOMPHOCERAS PLENUM. Page 33. Fig. 3. Lateral view of a specimen which preserves the chamber of habitation with about fifteen attached air-chambers, showing the form of the shell and depth of the air-chambers, of which there are several shallow ones near the grand chamber. Fig. 4. Id. Septum showing the circular transverse section of the tube and the position of the siphuncle. Corniferous limestone. Colwmbus, Ohio. ■ 3 ) PLATE CXXII. GOMPHOCERAS ABSENS. Page 3-2. Fig. 1. Septum showing the transverse section of the tube, and the position of the siphuncle. Schoharie grit. Schoharie, N. Y. Fig. 2. Septum of a larger individual than the preceding, showing a more elliptical transverse section. Schoharie grit. /Schoharie, N. Y. Fig. 3. Ventral view of the chamber of habitation, showing its form and the sinus in the margin constitut- ing the small aperture. Corniferous limestone. Clarence Hollow, Erie county, -N. Y. GOMPHOCERAS MINUM. Page 34. Fig. 4. Doi-sal view of the specimen, showing its ovoid form and small aperture. The substance of the shell has been replaced by silica, which obscures the extent of the chamber of habitation, and surface-markings. Hamilton group. Ohio Falls, near IxmisvUle, Kentucky. GOMPHOCERAS FAX. Page 32. Fig. 5. A compressed specimen, preserving the chamber of habitation and about eighteen air-chambers, showing the point of greatest gibbosity and the gradual taper of the tube toward the apex. Schoharie grit. Schoharie, N. Y. GOMPHOCERAS IlLjENUS. Page 32. Fig. 6. Ventral view of the chamber of habitation, showing the small aperture and the lateral extensions of the large aperture. Schoharie grit. Schoharie, N. Y. GOMPHOCERAS CAMMARUS. Page 32. Fig. 7. Dorsal view of the chamber of habitation with five attached air-chambers, showing the crenulated zone, and a portion of the strong test adhering to the internal mould at the margin of the aperture. Limestone of the age of the Hamilton group. Lexington, Scott comity, Indiana. GOMPHOCERAS POTENS. Page 35. Pig. 8. The internal mould of the septate portion of an individual, showing the form of the tube and the great depth of the air-chambers. The septum toward the apex is crushed and the true posi- tion of the siphuncle cannot be determined. Its position as it appears in the specimen is repre- sented in the figure. Waverly group. Medina, Medina county, Ohio. LIS '^'1^^ - ■ patei' -"iM'>' ■ • x- PLATE CXXIII. GOMPHOCEKAS GOMPHUS. Page 32. Fig. 1. Lateral view, showing the air-chambers, undulations of the tube, the crenulated zone, and cham- ber of habitation. Some of the crenulations are seen extending over the walls of the chamber on the right side of the figure. The impression of the ventral valve of a Crania is preserved upon the chamber of habitation. Comiferous limestone. Delhi, Delaware county, Ohio. GOMPHOCERAS MANES. Page 34. Fig. 2. View of the specimen described, showing its extremely compressed condition, and the depth of the air-chambers. The surface shows several branches of polyzoa and young brachiopods which were probably attached to the shell. Genesee slate. South of Allien, Erie county. ! ' ■ ■ : , ! : f i i Palaeontology of NY.VolY.P"! s,,,,. 1(111 ('111 ( icncscr slate i i ^ I [I PLATE CXXIV. < '\ KTOCERAS CITUM. Page 36. Pig. 1. A specimen retaining the test ami its ornamentation over the entire exterior of the tube. Upper Helderberg limestone. LeRoy, Genesee county. Pig. '-'. The internal mould of an individual, showing the revolving furrows of the erennlations. and the transverse markings correspo i ling to the foliate expansions of the test. Dpper Helderberg limestone, Falkirk, Urit county. Fig. 3. The retral sinus in the expansions of the test, as shown on the convex or ventral Bide of a speci men. This figure is taken from a gutta-percha impression of a natural mould ami enlarged two diameters. Upper Helderberg limestone. Cayuga, Ontario, Canada Gyroceras Nereus. Page 36. Pig. 4. \n enlargement to two diameters, of the ornamentation of the test on the ventral side of the tube, showing a marked difference in the sinus of the ornamentation from that represented in figure 8 of this plate. Corniferous limestone. (' lurry Valley, Otsego county. Gyroceras laciniosum. Page 3G. Fig. 5. Lateral view of the specimen, showing the curvature of the tube ami the transverse ridges corre- sponding to the ornaments of the test. The matrix preserves the characters and shows the ex- tent of the fimbria.. Fig. >i. Id. Outline, showing the transverse section of the tube. Corniferous limestone. Cherry Valley, Otsego county. Cyrtoceras Jason. Page 36. Fig. 7. Lateral view of the internal mould of a large individual, showing the transverse ridges and rows of nodes corresponding to the expansions and tubular spines of the test. Several of the trans- verse lamellae are seen in the matrix adhering to the dorsal side of the tube. Schoharie grit. Clarksville, Albany county. palaeontok ^ yy\ PLATE CXXV. Nautilus (Discites) ammonis. Page 38. Lateral view of the internal mould, showing the expanded aperture, the extent of the chamber of habitation, the depth of the air-chambers, the direction of the septa, and the large open umbilicus. Upper Helderberg limestone. In the drift, Ann Arbor, Michigan. - . . \- PLATE CXXVI. Nautilus Hyatti. Page 37. Fig. 1. Dorsal view of a plaster cast, taken from the natural mould, showing- the form of the tube, and the well-preserved surface ornamentation. Hamilton group. Cumberland, Maryland. Nautilus oriens. Page 37. Fig. 2. Longitudinal section of the individual figured on plate 106, Pal. N. Y., vol. v, pt. ii, showing the capacity of the grand chamber, the septa, and remains of the moniliform siphuncle. The inner volution has been filled with calcite, and the septa removed, but a portion of the beaded siph- uncular tube remains in situ. Hamilton shales. Richmond-mile, Schoharie county. Nautilus pakallelus. Page 38. Fig. 3. Ventral view of the specimen, showing the gradual enlargement of the tube and the parallel re- volving ridges of the test. Fig. 4. Id. Lateral view, showing the curvature of the tube, the angular periphery, and the concavity of the last septum. The parallel revolving ridges are seen to be less frequent than on the ventral side. Fig. 5. Id. The last septum, as preserved in the specimen, showing the subcentral position of the siph- uncle, and the lenticular transverse section of the tube. The dorsal side is more convex than the ventral, and the carinations of the lateral angles are directed upward and outward, Coal measures ? Ohio ? Nautilus (Discites) Marcellensis. Page 39. Fig. 6. Dorsal view of a well-preserved individual, illustrating the essential features of this species. The variation in the enlargement of the dorsal, ventral and lateral sides is well contrasted. The dorso-lateral margin is continuous and slightly reflected, while the ventral angles are marked by a row of nodes. A single revolving line over the siphuncle indicates its position and that of the ventral side. Four segments of the siphuncle are exposed, showing its concavesides within the cavities of the air-chambers. A portion of the test is adhering to the ventrum, preserving the cancellate ornaments and the broad sinus of the concentric striae over this side of the tube. Goniatite limestone. Manlius, Onondaga county. Gyroceras Stebos. Page 36. Fig. 7. Lateral view, showing the enrollment of the tube and the strong elevated nodes ornamenting the lateral angles. Traces of the transverse stria? are preserved near the aperture. Waverly group. Warren, Pennsylvania. • - s • SI ?l-;: \ r'- PLATE CXXVII. GONIATITES AMPLEXUS. Page 39. Fig. 1. Lateral view, showing the chamber of habitation, comprising- nearly an entire volution, the surface- markings, one of the revolving ridges on the periphery and the direction of the sutures as ex- hibited in the last septum. Tully limestone. L«d.i Landing, Seneca lake. GONIATITES COMPLANATUS. Page 40. Fig. 2. An illustration, similar to fig. 8, pi. 70, Pal. N. Y., vol. v, pt. ii, to show the direction and disposi- tion of the septal lines. Hamilton group. Oeneseo, Livingston county. GONIATITES VANUXEMI. Page 39. Fig. 3. View of the septa of two chambers of adjacent volutions, showing the transverse section of the tube, the size of the siphuncle and the embracing of the volutions. Goniatite limestone. Manlius, Onondaga' county. Fig. 4. Lateral view of a small example, showing the umbilicus ami inner volutions. Goniatite limestone. Fig. 5. Id. Preserving the bulb which forms the initial extremity of the tube. Goniatite limestone. Fig. 6. Ventral view of a young individual, showing the double revolving ridges of the periphery and the ventral lobes of the septa. A portion of the test is preserved with the broad sinus in the stria? over the ventrum. Goniatite limestone. Manlius. Onondaga county. GONIATITES VANUXEMI, Vlir. NOD1FERUS. Page 39. Fig. 7. Lateral view of a specimen found in the shales of the Hamilton group, showing the surface strise and septa, and a row of rounded nodes on the umbilical side of the lateral face. Hamilton shales. Cherry Valley, Otsego county. GONIATITES PaTERSONI. Page 40. Fig. 8. Ventral view of a fragment, showing the ventral lobes with the line of the siphuncle, and the dis- position of the septa. Fig. 9. A septum drawn from the reverse of the end of the preceding, showing the lobes and saddles. Portage group. Paterson's Creek, Livingston county. GONIATITES UNIANGULARIS. Page 39. Fig. 10. An enlargement to three diameters, of a specimen showing the direction of the septal lines. The air-chambers covering the smaller part of the visible volution have been removed, leaving the inners walls of the chambers exposed, which are striated by peculiar wrinkled or interrupted lines of organic nature. Hamilton group. Pratt's Falls, Onondaga county. GONIATITES DISCOIDEUS. Page 39. Fig. 11. Lateral view of a specimen, showing the surface markings, the form of the aperture, and the striated filling or area around the umbilicus. Fig. 12. Id. An enlargement of the umbilical area, showing more in detail the character of the concentric interrupted striae. Hamilton group. Western New York. ' palHBontologyofNYVolV.Pt II Supplemem ; PLATE CXXVIIL GONIATITES 8INDOSU8. Page 40. Fig-. 1. Lateral view of a large well-preserved specimen, retaining the test ami ornaments over the grand chamber, and showing the suture-lines of the septate portion. Fig. 'J. The internal mould of a portion of the outer volution of an example, showing a somewhat broader saddle in the middle of the lateral face, than the preceding. Indications of the strong lamellose linos of the ornamentation are preserved toward the periphery of the chamber of habitation. Portage group. Ithaca, Tompkins county. GONIATITES IXION. Page 40. Fig. 3, Longitudinal section, showing the depth of the air-chambers, and where the section is through the median line, the reflection and extension of the septa for the passage of the siphuncle is also shown. (Joniatite limestone. Rockford, Indiana. GONIATITES OWENI. Page 40. Fig. 4. Longitudinal section of a large example similar on the exterior to fig. 7, pi. 73, Pal. N. Y., vol v, pt. ii, showing the great extent of the chamber of habitation as presented in this species. Fig. 5. Id. Of a small individual, showing the septate portion to the initial extremity. The chamber of habitation appears to occupy the greater part of the outer volution as preserved. Fig. tj. Id. Through the median line, showing the space between the termination of the septa and the inner wall of the shell, for the passage of the siphuncle. Fig. 7. III. Similar to the preceding, but showing the siphuncular tube indicated by a difference in the color of the material filling the air-chambers. The walls of the siphuncle as thus indicated are not calcareous, but form an organic connection between the septa, Goniatite limestone. Rockford, Indiana. ■ ontoloevof NYVolVPt'I Supple v ^X^. -■■ PLATE CXXIX. Orthoceras Dagon. Page 28. Fig. 1. The septate portion, showing the enlargement of the tube, and the depth of the aii-ehambere. Corniferous limestone. Columbus, Ohio. Cyrtoceras subcompressum. Page 35. Fig. 2. Longitudinal section of a nearly entire individual, showing the curvature of the tube, the extent of the chamber of habitation, the depth of the air-chambers and the characters of the nummu- loid siphuncle. Limestone of the Clinton group. Piqua, Ohio. Fig. 3. Septum of another specimen, showing the excentric position of the siphuncle. The vertical diam- eter of the figure is the ventro-doreal. lBiErJ*JSai !f!BESflD53iifiaiIJL® Ifc Saa^JSIl? Sk&iJjEi'i ' :■ I • PtU Supplement [ .-.. ■ "%. "^BBCT _ et Utt 4 V «WVv/ QH 105 N7N3 v.28 Biological & Medic*] Natural History of New York PLEASE DO NOT REMOVE CARDS OR SLIPS FROM THIS POCKET UNIVERSITY OF TORONTO LIBRARY