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SMITHSONIAN INSTITUTION UNITED STATES NATIONAL MUSEUM Bulletin 88
REVISION OF PALEOZOIC STELLEROIDEA WITH SPECIAL REFERENCE TO NORTH AMERICAN ASTEROIDEA
BY
CHARLES SCHUCHERT
Professor of Paleontology, Yale University New Haven
WASHINGTON GOVERNMENT PRINTING OFFICE 1915
BULLETIN OF THE UNITED STATES NATIONAL MUSEUM.
Issuep Marcu 20, 1915.
ADVERTISEMENT.
The scientific publications of the United States National Museum consist of two series, the Proceedings and the Bulletins.
The Proceedings, the first volume of which was issued in 1878, are intended primarily as a medium for the publication of original, and usually brief, papers based on the collections of the National Museum, presenting newly-acquired facts in zoology, geology, and anthro- pology, including descriptions of new forms of animals, and revisions of limited groups. One or two volumes are issued annually and dis- tributed to libraries and scientific organizations. A limited number of copies of each paper, in pamphlet form, is distributed to specialists and others interested in the different subjects as soon as printed. The date of publication is printed on each paper, and these dates are also recorded in the tables of contents of the volumes.
The Bulletins, the first of which was issued in 1875, consist of a series of separate publications comprising chiefly monographs of large zoological groups and other general systematic treatises (occasionally in several volumes), faunal works, reports of expeditions, and cata- logues of type-specimens, special collections, etc. The majority of the volumes are octavos, but a quarto size has been adopted in a few instances in which large plates were regarded as indispensable.
Since 1902 a series of octavo volumes containing papers relating to the botanical collections of the Museum, and known as the Contribu- tions from the National Herbarium, has been published as bulletins.
The present work forms No. 88 of the Bulletin series.
RicHarp RatuHsBun, Assistant Secretary, Smithsonian Institution, In charge of the United States National Museum.
WasuHinoGTon, D. C., January 27, 1915.
3
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TABLE OF CONTENTS.
Page.
Plotter eatin Ran ease nae as cue as ie S aie. ce aoa Sa cain tecuoes seeioace 9 Terminology as applied to the skeleton of Paleozoic Asteroidea..............- 3 Finding list of Paleozoic Stelleroidea.............----622-- 22 eee eee ee eeee 18 Remarks on the development of Paleozoic Stelleroidea.....................-- 27 OO Op ed ars eee oan anette Ceo tle Visa autelrat ih hon aah oe 27 IYGLEUD OOM ee meses wi skie ce eee enced Set oesc Rees ss ute soaks 27 Preseryvatioiand OCCUITONCE< se22s. 2c sac ose ces caw steed Jose sed 28
PPO MONIC cone seei sate chee cman 5G el cn mcicahs tal merce gtonsa meanees 30 GroriprA OG Ose nV IONS ae Sale me tie eee eee cea ios ti ig bec ee ee 30 The most primitive fossil starfish...............--.20-- eee ee eee 3L
Origin of the wriggling type of starfish.........-................-. 32
PENG WSR TACIClO sano. es cadens es eg asics Sion eee odals tre OM Sa meee a ke 34
RU IBhOe CIM eer ene eee ants Skea sions nse h wot eae aoe cts ts 36 INOPONCTAUOMN s Sedocas cis cae cities da Se raieanewaden Sader swig tense weeds 37 Number and character of Tays.:-c.5sts0 ts ase 2555 o ectec ee se beee 38 Wevelopment Ol ine Pals. cases sso Hos Sas ate ete ees Meade ee 39
PNET eI eo gte yee oe ees aaa aie ny 2 nic Sta cies ae WS aoa feet ie at ets Sees 39
PUAN POUL Oe ete eet ces oe aie SN es, i a a aise Re ae a ees eee 39 ORIN AU ye se eee eect sia 2d et Se Bara cle wee Nou 41 PUL NOT AL deity tas Stren we eee domme ak tek aos Laces ede 41
CLA Cra Ney ee ere els Geel Sines in eae eee heme 43 (iirainarprian liste So oeccn coe eee eet wt ek met Lee meat 43
PUPA ATOM AN hae a cece sas aka ae eae east se waka Ses ne SOL ames 45
U25 A>) 12 Re a Se ge me Co ee 46
CCE SSOE, DUALS a eet se eons Ook cee ees ee is th eer Sg Bia ahaa Se 47
UC) {GURTLE: Fig 12), < Semen a ee eS aaa em Ua 48
SPGTiarO Oe ee Peta eee se te Aare Ss ees ahaa ea 48 Peinony Cis Ol atone se. cee eee ot ores SoS tite he ee 49
POU Use SAU Letra eae eee Ts cae eee oe. ec oh. 2, ote ests 49
MNTHGE OAC UIA ATGAR fo. be.cnn ds ded e scete sn DES e ees See ese se cea ees 50 Wlagsttiea tion aui,eo cts. = Soe Sea ee Sea wemm ce ee eee eer eee 51 Catalogue of Paleozoic Stelleroidea ..........................------ 51 Description of genera and species.........--...------ ee a 51 Silane POUCLOIN Od ts Sten eee Se Sec ahs a nots aE ads «ee eee Se ies 51 SUbeiads AeveLOllen. 2205365 .5 oh Seon of adtnpeniis a doe snes cosa seas 51
GANONG ZOU ee te seh Se ese otk aoe eee nk een eae oa 51
Family Hudsonasterids: 2.202.254 2- 2s Pees ap ace eeacees 53
EELS ONUUBIED it oa yn Aaa Od we oehee Sen Sea oun eae oe 53
RU OS LET Se ence etal eMart tts nyt aise eae so 65
WAMU Ys EAlPAStOLIO hes, 3.612 eon end rhe tise de Seaton 66
Ma TER PENS ces te as vty Pe eih nyt wT a oc Ri 2 zal 67
AU BINGIORL Ete toe ees Miers enon 3a Shs Sb a See cts Daleiocie 72
6 TABLE OF CONTENTS.
Description of genera and species—Continued. Class Stelleroidea—Continued. Subclass Asteroidea—Continued.
Phanerozonia—Continued. Page. Family: Promopaleasterid®: -.13 2) ococ aoe ase Soc eee 73 Subfamily Mesopaleeasterine.......-......-.----------- 74 Meso paler raters. :c 552 ot ae eee ee eee 74 Sipaniasten ss nck otek i lee he eee Sapte ee tere creas 95 MOMS a hESC A SNe 3 oOo ee 96
Devon aslenis agement wes «diye! Ste Es aber ret tee eae 97 Subfamily Promopalecasterines..45) 09) ace. ce oe eer 102 Promopalzaster. 2.2 s.cscctheae te aoc gee eee 102 Subfamily Anorthasterinse. 792222 Sa Ge es Oe ee 125 Anorthaster ss cs2.cs ee oan SNe oe Se ae aes ee ciate 125
Family Xenasteridse. es eos See ee ee eae 128 Kenaster se eos heebasd ao sess wan es fee ee eee eee eee 129 Agalmastercs. 2 JscciSens3s fcisscs see ae eee eee oe RRCNASER sais cia stein Sas Sraiaic Ee ee eae alco eee eee 133
TEU CUASLER ae cio ales aici nee sins apfo SS See tat eeee ae 133 Trimmer astenc oo oid cdi oeeot a is ad SE oe ee 134 Family Neopaleasteridae 220-22 .Va-8 eeu ae See eee renee 134 Neo palsaster: cfs Js lh cok Oikin tc Socata tee eters 134 Family Palasterinid so. 3.1.2.5 6 ee. acct ae ce ee one aes 138 Petrasters: sxidachicsbaest 2 toc 3 SOS eS eee eee eee 138 Dindstromaster 00055 sit. s Sade oe ee ee 148 Palasterintcccen2 32 255-3 Sas Oa eaeeeeee 150
OT ONUSCET 5523 os e'viecicin FEEL SRE CLE DEO ee eee 154 Palvostellass cee es ee eee sie yahee metab A ne CODE 155 Paeudopalasterinas.2% 5.1 see sete ee 156 Family Lepidasteridies: ...0<.) .2: ic (tees ae Pines See ee eae 157 Te pidasten. ccs s No so2 56 25 52a aera eaten 158 Felanthaster jas a5 wide lo oaths ak See Oe eee oe 159 Leprdasteretla. oi. coco 852 385.26 Bee 160 Family unknowit.\.-s 3is'2 1205.2 oats 3 SO Re eee eee 161 Astro pectetts jasa\ss<% sss bial tee s oes See See ek eae rete 161 ALATA 2 ccieins Sis we 'stetiial cck See Hate hee Wa eee 161 Cryptozoniasc).22ssceso. seth ces Pewee eee eit se ee ae hee eae Family Stenasteridee:sa.8 Seis sh esate eee eee 163 WLen aster 12% iting Pecan e es hs te Se eee oe aces 163 Tetraster 5. ccetee Sos een nea ese ee eee 167 Famil y-Monasteridee 2:3... Gens: Sock ene ee eee 170 Mondste?.ccntcn csicee at oo ssid bee eset See ee ee Family Urasterellidee... 82225 S20 2 Sa ee ee pees 172 Urasterella. ss... 22 csic 2 ce Peet eens ee a ee eee 173 Family Calliasterellidee.....<225-i22-2-e ses See eeere ee aeons 190 Calliasterellascscccccickye seacnd deere ete a era abe areas 190 Family Compsasteridee. -2..02cscnschss semen cece re sles ine 191 Tackelaster ssc sshs cs BES ee hc eee 192 Comipsaster: jcc sam cc ence ee ere ee eter 192 Family Schuchertiide:-..-)..5-2-.. tote ooseeaccate eee 194 Schucher tia: .coscicdese east SR ee ee Bare ee eee 195 «Family Palasteriscid se... oiiiicd sawn ee aeee eu kok eee cies sense 199 POVASTTISCUS = /a 552 Taino Sa bs eee oe oie als ine axle see 200 Rechinasterella. <3 2 cc050s occn emia See eae ee eee 200
TABLE OF CONTENTS.
Description of genera and species—Continued. Class Stelleroidea—Continued. Subclass Asteroidee—Continued. Cryptozonia—Continued.
Family Palasteriscidee—Continued. GOMER eb eo ea Wace ciate wine'e © eineaie 28 Chetropteraster.......0.0.-- cece eens erence ceeeeccees
Family Schoenasteride........-----------++- eee ee steers WEHPNARIER ona ied ongenoeee sedate ecyaeltet ne eas
Family Paleosolasteride........-------+-+++++eeescertere ee Paleoslasters oe ccna tens Sais se eae es ba bs ceicaacs ee chanGSteHS cus od cu ceases sae viaeee teers tee hws ese FOCHANOGISCOSLE? - 200005 s 2. 2 Sone e ce cse nes coesesseseceeess BANOS soos cs cscc cc aw lov skibe oe vie slesnde eee ens en's os'3
Subclass Auluroidea........-.- cece cee cece eee e eee e nce rec ececees Order Lysophiwres,,c.<.2.cecsens sedan es Koes selene sessess esse Family Protasteride.......----------2eesceeeee reece recess PO STeTe ae saci ne slomiele ie ois = clociraite whe nie’ > wsisia: ss neers HOPRUG CD waiguis 2 toc Beane aeaeeeine stot ade saces cies eee DORCNI Gana wacda cece aoa seeeca ee aerGinds ase sa Se PRIPUTA trees. bu nett lSs eden oad eee ee ase ees eer ety (Protaster. doco. ceksase'= SSeS Sa cl wecse Pad eee Sees e sans AUGPIAANER Gee wnosa saw es seen t's Heeg sce proses oncinte se GREGOTIUTG «ce an eain esses ng oe eet Se ease tin wanes Bundendachia. <2. .1000 20052502 = Pictu eer eesaaees Palxophiomy20......-.---- +2022 cece eects reece ececete Family Paleophiuride.........-.--------++---+eeeere eres Palxophiura........0c0cese ee ee eee e ses es esc ececseseees WEITIZUTO. sae a ckcesa meek nl see duc teen ease cece eae FG Ster ele. coe. asin. «oid zo ew we ess dais winiel sie oleae # = aise’ PEON USTh scooter Res ca dS eee taemlse eae. <cieiekieroe sans Family Encrinasteride.......-------------++e+-rereec rece Pneriasler noc oo cc dank eed nese ewide px TREES esas Scien Order Streptophiuree...........-- 2-2-2 eee cece ence eee e cere n ees Family Ophiurinide...........---- Jig sac haeancinns eae eee ODRUUTING..022 2000 c0.00csn ene nce ss stent ec gcetaeeceteers Tremalaster. o& ~ <<. ce/a's 0214 BA NM teams dues a beni eee Family Lapworthuride..........--.-----2--+seecece reece eee SQUAMOSIE Sais. 22 -socessase sein stint = Hels Baie een ~isie< Dapworthurd.....-.cccc-escesccccecccescscesesonccsesss Sir ideter 2 3c s ences on eos a wae aa NR eee eas ss BiCMaloniGsecses ea dow ences wena o ences sews aasee aces RO PAloCOM th on ss << swine scene cn ners se seee ces enetseseoes
NECA STi: ee ee ee ee ee ee or Symplerurd....-- 2-0 -e eee cece eee e eee e cence ener eeesceee HUT CUSLER = ac dace ocla sais oo se esas peceae ens -5 5 sama Palastropecten.......-.2---2seccec cece eee en ee encececeee Family Eoluidiidz PFS E ee Sa seew rd Le esta te ae segicn sss sinensis ote Eospondylus.......2.0-0-ceccece ccc ccccccecencscccercs Miospondylus........200-02ceceecc cece eee ceececeneecees Family Aganasteride...........-------+2-0e eee e eer eeeecee AGONUSUE oi ocs cso sialiescetcctecseseleaenscccssccsceees Family Cholasteridee...........----------2-eseeeceeceeeeeee OHDUISLET ee ee oa as os =o w= 9 ine cin nw at eee aleinm site's ss
Secale aes ee me eine = a aie ele nee e 6, 6 ea 'a 6 616s ere ee os
8 TABLE OF CONTENTS.
Description of genera and species—Continued.
Class Stelleroidea—Continued. Page. Subclass‘Ophiuroidea.:2iis822..)- :Seeketho: Joep eeseee ae ae eee 267
Family Onychasteride::.. -. @occ- ot 5) =e eee oe ae 268
Oniychaster sirctse oh apt bcs Rape AA eee ae Re se te 268
Forms whose relationships:are unknown): 2545... -8-lsseet ss eeee eens 274 Cribellites carbonariuss.<.- 26 9- = -35--- ==: Masa SE sees oe es 274
Order Ophiocistia. ....0.2sjsceeede 3, eat ec seer eee eee eee 275 Pamily Bucladiid ss s2i.o222. 1. - Poe he 1. Se ee Se ee 276 Pela da. io ooo, reise tS 5,2 aa a sicko pany beh ahah ae ee Ee ect Reeae 276 ERUAREMON Spd og Soe Weslea ia. basses < <eie Me ins BS ie oe ce e 279 Bibliography: osc <n-\05..seteepies a ees - <a oe a ee ee eee 281 Bxplanation of plates..4: 4....:teaaah she oSet ate ee Oetes auc one meee 289 BTM NC ea oe ear ate onl eee ee 303
REVISION OF PALEOZOIC STELLEROIDEA WITH SPECIAL REFERENCE TO NORTH AMERICAN ASTEROIDEA
By CuarLes SCHUCHERT Professor of Paleontology, Yale University, New Haven.
PREFACE
This memoir had its inception in 1896, and came about through the force of circumstances. The writer, at that time assistant curator in the United States National Museum, was made aware of the desire of Mr. I. H. Harris, of Waynesville, Ohio, to present to that institu- tion his extensive collection of Ordovicic fossils. He had long known Mr. Harris, having met him as a young man, about the year 1876, at which time the Harris collection was already widely known, not only for its quantity, but more especially for its many choice speci- mens of the rarer species of starfishes, crinids, and trilobites. Twenty years later came Mr. Harris’s desire to present to the National Museum the collection upon which he had been at work for fifty years. This gift brought to the National Museum not less than 40 asterids, 35 (31 on one slab) ophiurids from the Cincinnatic strata (the great majority from the Waynesville formation), besides an asterid and 12 specimens of Onychaster flexilis from the Keokuk formation at Crawfordsville, Indiana. Some years later the National Museum acquired the very valuable E. O. Ulrich collection, in which there were also many good starfishes. Accordingly, it is safe to state that in no other museum are there so many Ordovicic asterids, in so great a variety and in such excellent preservation.
The material of the Harris collection seemed to show that its com- plete study would not only reveal much new knowledge, but give an insight as well into the probable evolution of the Paleozoic starfishes. When these facts were made known to the then director of the National Museum, Dr. G. Brown Goode, he asked the writer to invite Mr. Harris to join him in a work on the Ordovicic starfishes. This was done and Mr. Harris was greatly pleased to undertake the joint authorship. He did all he could to further the work, but it went very slowly, because the present writer was so much occupied with curatorial work as well as the arranging of museum exhibits for the expositions in which the United States Government participated and which came
9
10 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
nearly every year. Unfortunately, Mr. Harris died on October 17, 1897, when the work was still in the first stages.
At odd times during subsequent years the writer kept up his studies and in the spring of 1904 the work on the Asteroidea was practically completed. Then came his appointment to the chair of paleontology at Yale University. Here new duties and new lines of thought kept him away from the study of the Paleozoic ophiurids which had been planned, but the hope was strong that somehow the time would be found to complete the work. However, this hope has not materialized, others have gone to work on the starfishes, and one genus and general- ization after another has slipped away. Therefore it was thought best to revise what had been done, bringing the asterids up to date. In regard to the ophiurids, it was found impossible to restudy the specimens, but as the writer had kept abreast of the literature, this was put into order and is here presented, in the hope that subsequent workers will find it useful in enabling them to find the references on any species and the taxonomic status of any form.
A study of the specimens in the Harris collection made it plain that no satisfactory taxonomic and systematic results would follow unless the undertaking also embraced many other Paleozoic forms, of Europe as well as of America. Species and genera had been pro- posed in a very loose manner; in fact, most of the Paleozoic litera- ture on asterids and ophiurids up to the time this work began had no other value than to force the reviser under the rules of nomencla- ture to recognize the names proposed. The International Rules of Zoological Nomenclature have here been strictly followed. Under these circumstances, all of the type-specimens had to be seen, and most of them have been accessible. In this way the work finally came to be extended to all Paleozoic Stelleroidea. To make it plain how little the American Paleozoic starfishes were known in 1889, it will suffice to give one example: Miller in his North American Geology and Palaeontology lists 23 species under Palzaster; in the present work there is but a single form of this genus, the genotype, P. niagarensis, the remainder having been distributed among seven genera, all new and proposed in the past few years or at this time. As a result, every paleontologist will be obliged to disregard what he has learned re- garding American Paleozoic starfishes and start anew. To facilitate this, a list has been prepared and is here presented of all the names so far given to Paleozoic asterids and ophiurids, with cross references to the names adopted in this work.
Now that this study is finished, at least for the present, it is plain to the author that his species and genera are also in some cases too comprehensive. The future student will restudy the specimens along with the new material and go more deeply into the detailed structure of the parts. He who attempts this, along with painstaking recon-
REVISION OF PALEOZOIC STELLEROIDEA. Ti
struction of the skeleton as it was in life, will learn where to separate and what to reject.
During the past 10 years, Schéndorf has revised most of the German asterids and has studied deeply into the structure of the ophiurids. His work is very detailed and the best extant on the Paleozoic forms. Every student of Stelleroidea intending to do thorough work will have to examine his results. In classification he has laid the founda-— tion, and has shown that some asterids are not Asteroidea at all, but that they and the bulk of the so-called ophiurids of the Paleozoic must, because of their peculiar structure, ambulacral and otherwise, be referred to another class, the Auluroidea.
In regard to the evolution of the Asteroidea, the writer hoped to find the time to present his views concerning it in detail in this memoir, but that also is not possible. However, the main lines and often the generic directions of organic change are stated and will be found either in the introductory pages or scattered through- out the work, generally in the remarks under the generic discussions. These results in connection with the work of Schéndorf, it is thought, ought soon to place the Paleozoic Stelleroidea in such order that a final classification, based on ontogeny, chronogenesis, and phyl- ogeny, and embracing not only the Paleozoic forms but those of Mesozoic, Cenozoic, and Recent time as well, can be made.
Many museums and individual paleontologists have loaned the writer the specimens in their collections or in their keeping, and he wishes here to thank them, one and all, for these loans. The greatest bulk of the material studied is of course in the United States National Museum in the Harris and Ulrich collections; a number of Trenton specimens and some from the English Siluric have also been given to the National Museum by Mr. Walter R. Billings, of Ottawa. Since the writer has been in New Haven, Dr. R. S. Bassler, of the National Museum, has often kindly helped him to further his studies, and during the past year has made a large number of photographs of the specimens under his charge. The many Mississippic speci- mens in the Frank Springer collection have not been studied.
The author is greatly indebted to Dr. F. A. Bather, of the British Museum (Natural History), for a large number of gutta-percha and wax squeezes made by him of certain species in that great museum. These casts, which are all in the United States National Museum, have enabled the writer to understand several genera that otherwise he could not have worked out. He is also indebted to him for many bibliographic corrections and suggestions.
The second largest American collection is at Harvard University, in the Museum of Comparative Zoélogy. Most of the material is in the Charles D. Walcott, Charles B. Dyer, and Charles Wachsmuth collections. In the first-named collection there is excellent material from the Middle Ordovicic; the second has many fine specimens
12 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
from the Cincinnatic formations; while the Wachsmuth material has species from the Mississippic. To all of this material the author has had access through the kindness of Director Samuel Henshaw and Profs. R. T. Jackson and P. E. Raymond.
At the University of Chicago there is a great deal of excellent material in the W. F. E. Gurley, Charles Faber, and U. P. James collections, to which Weller has added other specimens. All of this material has been studied through the courtesy of Prof. Stuart Weller. Most of it is from the Cincinnatic formations.
All of the specimens described by EH. Billings and now in the Vic- toria Memorial Museum in Ottawa, Canada, have been seen at one time or another. In this matter the writer was much aided by the late Dr. J. F. Whiteaves and more recently by Drs. P. E. Raymond and EK. M. Kindle, to the latter of whom thanks are also due for several photographs reproduced in this memoir. Most of the speci- mens are from the Ordovicic.
In the University of Toronto there is much material from the Ordovicic and Siluric in the Sir Edmund Walker collection, and there may be studied a great many specimens of Stenaster salterr. All of this has been seen through the great liberality of Prof. William A. Parks.
The genotype of Palzaster, from the museum of Cornell University, was loaned to the author at different times by Prof. H. S. Williams. It is one of the best preserved of Paleozoic specimens and has become very valuable because of the continual discussion that centers around the species, P. niagarensis.
To all the specimens in the Peabody Museum of Yale University access was had through the kindness of the late Prof. Charles EK. Beecher. Among them is the unique branching form, Hucladia beechert.
Photographs have been made for this memoir by Dr. John M. Clarke of specimens in the New York State Museum, and by Prof. George H. Hudson, of Plattsburg, New York, of other material. Prof. Arthur M. Miller loaned two specimens that he collected and deposited in the State University, Lexington, Kentucky. Prof. George W. Harper, of Cincinnati, loaned a specimen of Palzaster clarkana (= Hudsonaster incomptus).
Nearly all the original drawings were traced from the specimens by aid of the camera lucida. These outlines were then inked and shaded by the late Dr. J. C. McConnell, a draftsman and artist of the first rank.
To Miss Clara Mae LeVene the writer is especially thankful for the great interest she has taken in getting the manuscript into order for the printer, keeping the bibliography up to date and correctly citing it, and for the careful reading of the proof.
REVISION OF PALEOZOIC STELLEROIDEA. 13
TERMINOLOGY AS APPLIED TO THE SKELETON OF PALEOZOIC ASTEROIDEA.! Abactinal.
See Body-wall. The integumentary skeleton opposite to that having the ambu- lacral grooves, or that of the upper or dorsal side of the animal. Also known as the aboral surface. See Actinal.
Aboral. See Abactinal. Accessory plates.
This term refers to the abactinal longitudinal columns, or transverse rows, of small plates between the radials and supramarginals (=radial accessory plates or dorso- laterals), or between the inframarginals and supramarginals (=ambital plates or intermarginals), or where there are no radials, to all the ossicles between the two supramarginal columns. There may also be accessory actinal plates which are termed accessory interbrachials, accessory actinals, or interactinals. The accessory plates form the secondary skeleton and are inserted between the columns of the primary skeleton. It is in the secondary skeleton that much of the specific and generic evolution takes place. See Interbrachial.
Actinal.
See Body-wall. The integumentary skeleton with the ambulacral grooves, or
that of the under or ventral side of the animal. Also known as the oral surface. Adambulacrals.
Thesingle columns of prominent plates adjoining the ambulacrals. There arenever more than two of these columns in a ray, one on each outer side of the depressed ambulacrals. They are generally large and thick and bear the larger, or adam- bulacral, spines. These spines may be inwardly directed and serve asa protection for the tube-feet. The oral armature in Paleozoic species usually consists of five pairs of modified adambulacrals, each pair being the oral projection of two united columns of adjoining rays. They are also called Adambulacralia. Also see Inter- brachial.
Ambital.
The abactinal space between the infra- and supramarginal columns, occupied by accessory plates. These are best developed in the axillary disk areas (disk ambi- tals), while those of the rays are referred to as ray ambitals. They are also known as intermarginals.
Ambulacral.
Ambulacral grooves (five or more), plates, or ossicles are situated actinally and per- radially along the center of the rays and disk. They are also called ambula- cralia, The ambulacral columns are in pairs, the interlocking movable plates of adjoining columns may be alternate or opposite (always so in recent forms), and the plates of a column may be superposed like the tiles on a roof. The podial openings through which the fleshy tube-feet protrude are situated be- tween the sutures of adjoining plates. In early forms there are but two columns of podial openings in each ray, one on each side of the axial line, but in later forms there may be as many as eight columns. The ambulacral grooves may be tapering or petaloid.
Anal opening.
The only Paleozoic form in which an anal opening may exist visually is Hudson- aster, Here it is on the disk between the central plate and the madreporite. The anal pore is nearly always obscured in fossil starfishes, and is absent in some recent species.
1 Also in the main applicable to the Auluroidea and somewhat to the Ophiuroidea.
14 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Arcs. See Azil. Azil.
The angle formed by the junction of the rays. Also known asarcs. In primitive forms each axil is occupied by a single plate, the axillary inframarginal. In others this plate is crowded orally and its place occupied by two prominent proximal inframarginals. In forms with large disks having well-developed marginals these are termed disk marginals. Also see Ambital and Interbrachial.
Bivium.
The two rays of a starfish that inclose between them the madreporite. When oriented toward the student, the ray on the left is numbered 1 and the other on the rightisnumbered 5. A line drawn through the madreporite and the center of the upward directed ray (ray 3) divides the animal into symmetrical halves (=left and right sides). The upper left-hand ray is numbered 2 and the one opposite is 4. Rays 2, 3, and 4 form the trivium.
Body-wall.
The outer surface of both disk and rays, made up of movable calcareous plates which are either closely adjoining or form a more or less loose network of ossicles. These are held together in the living animal by connective tissue and muscular fibers, which after death soon decompose, freeing the plates. It is for this reason that fossil starfishes are so rarely found entire. Imbedded in the body-wall everywhere are blunt, short, calcareous spines, arranged in a more or less definite order, and often movable upon the underlying plates.
Covering the whole surface of the body, including the spines and pedicellarie, is a delicate membrane or skin, clothed externally with closely placed vibratile cilia, which keep the integument clean. The calcareous skeleton of starfishes is therefore integumentary.
Czxcal pores.
The openings between reticular plates for the protrusion of the respiratory ceecal processes. These pores are either restricted to the abactinal area or may be distributed over the entire body. The processes are also known as papule.
Central disk. See Disk. Central disk plate.
A prominent plate, most conspicuous in primitive forms, which often appears in the center of the disk. It holds the same position as the centro-dorsal plate in embryonic crinids of the genus Antedon. Also called the abactinal-central plate or simply central plate.
Centro-dorsal plate. See Central disk plate. Disk.
The central portion of a starfish. In this work, the term generally applies only to the abactinal central area formed either by the union of the rays, or by the rays plus the axillary areas. The mouth is in the center of the disk on the under or actinalside. Disk plates are the small plates over this area on the abactinal side. Central disk plate refers to a larger primary plate in the center of the disk. There may be other large primary plates, but these are more properly referred to the rays. See Radial, Interradial, Marginal, and Ambital.
Inframarginal. See Marginal plates. Interbrachial.
The actinal and marginal areas between the rays. These spaces have plates derived from various regions. In primitive forms, but a single plate is present, the axillary interbrachial, derived by crowding orally the axillary inframarginal. In other genera, inframarginals are crowded in pairs orally and form interbrachial
REVISION OF PALEOZOIC STELLEROIDEA. 15
areas, the interbrachial marginals. Or the adambulacrals may enter into the
construction of these areas, forming interbrachial adambulacrals. When the adam-
bulacrals and inframarginals are separated by small plates, the latter are called
accessory interbrachials; they may extend almost to the distal ends of the rays. Interradial.
A point half-way between the perradii. The interambulacral areas are inter- radial in position. See Perradial.
Interradial plates.
These abactinal plates are rarely retained in living mature starfishes. In many Paleozoic genera they are large, interradial in position, five in number, and lie inside the basal or proximal supramarginals and between the primary radials. They may be homologous with the basals of crinids. They are also known as genitals.
Madreporite or madreporic plate:
A sieve-like or spongy plate, with many irregular openings for the circulation of sea water into the so-called ‘‘stone canal,” or better, into the water-vascular system. It is commonly granular or striated, and in Asteroidea is abactinal on the disk, basally situated between two rays, but in the Auluroidea is prob- ably always actinal in position. In recent multiradiate forms there are species with more than one madreporite.
Marginal plates.
In general the plates which make up the marginal columns bounding the rays, or disk, or the entire animal. They are parts of the primary skeleton. In the early Paleozoic genera the inframarginal and supramarginal columns are usually not directly superposed, making one column of superposed halves as in Meso- zoic and Recent starfishes, but the former column lies outside or laterally of the latter. The inframarginals are then the true marginals, and form a part of both the abactinal and actinal sides. In the primitive arrangement the inframarginals adjoin the adambulacrals, but in derived forms with large pen- tagonal disks they are separated from the latter by accessory interbrachial plates. The situation of the marginals is, however, not always at the margin of the disk and rays, but they may retain their primitive position beside the adam- bulacrals; this is more especially true in forms having a well-developed pen- tagonal disk. These plates are also referred to as marginalia, supramarginalia, and inframarginalia.
In some forms the supramarginals are not recognizable as such, while the infra- marginals are well-developed; and in others none of the marginals are distinctly discernible. Sometimes the plates of the inframarginal columns adjoin one another, while those of the supramarginal series are separated by small acces- sory supramarginal pieces. Then the inframarginals may be separated from the supramarginals by ambital ossicles (see Ambital). A proximal supramarginal is the proximal] plate of a column and may not be homologous with the primary supramarginal in primitive forms. Proximal inframarginal is used in a similar way and refers to the proximal axillary plate, two of which of adjoining col- umns occupy an axil or lie on either side of the avillary marginal. The latter in primitive forms alone occupies the angle between the rays. The marginals in large disks without angles may be termed disk infra- and swpramarginals. The large disk of some species is formed by the oral crowding of pairs of proximal inframarginals, the interbrachial marginals.
Measurements.
The size of starfishes is usually given in millimeters along the greater and lesser radii, that is, from the center of the mouth or disk to the tips of the rays. The symbol for this line is R. The smaller radius is from the center of the animal to the center of the interradii; the symbol is 7. 50601°—Bull, 88—15——2
16 BULLETIN 88, UNITED STATES NATIONAL MUSEUM,
Mouth angle plate. See Oral armature. Ocular plate.
A single large, grooved eye-plate occupying the distal ends of rays and support- ing a sensory tentacle at the base of which occurs the eye-spot. They appearin the larval stage as the primary radials and with growth pass outward, remain- ing at the tip of the rays as the oculars. They are also known as terminals. These large plates are not present as such in early Paleozoic genera, and are
- unknown before the Carboniferous. Oral. See Actinal. Oral angles. The interradial actinal areas around the mouth. Oral armature.
The pairs of plates, usually five in number, composing the apices around the central actinal opening or mouth. In most Paleozoic forms the armature consists of the proximal modified adambulacral plates. These pieces are also known as Mouth angle plates.
In some Paleozoic forms (Hudsonaster) there lies in front of each pair of mouth angle plates a single plate; this is known as the Torus.
Gregory (1900, p. 241) writes that “the Oral Skeleton (or actinostomial ring) consists of a solid calcareous ring around the mouth. It is composed of thirty plates in a quinqueradiate starfish, there being always six times as many plates as there are rays. Each segment of the oral skeleton consists of two pairs of ambulacral, and of one pair of adambulacral ossicles. In Asterias [a cryp- tozonian] the ambulacral plates are more prominent than the adambulacrals, and project into the oral cavity.”’
When the ambulacral elements are the more prominent, the oral skeleton is said to be of the ambulacral type. This is only present in cryptozonians. When the adambulacral ossicles are the most prominent, the oral skeleton is of the adampbulacral type. This latter construction is the more primitive and occurs in all the Phanerozonia, but is also present in some of the cryptozonians,
Ossicles. See Plates. Papule.
In living Asterias, a cryptozonian, from between the spicular plates there rise from all parts of the external surface short and small integumentary protuber- ances that are used for respiration. In the more heavily plated Phanerozo- nia they are limited to the abactinal surface enclosed between the supramar- ginal plates. It is probable that papule were present in all Paleozoic forms having rounded or spicular ossicles, issuing in the open spaces between the plates. They probably were absent in the earliest closely plated starfishes, such as Hudsonaster. See Cexcal pores.
Paville.
Minute calcareous processes arranged around large spines. None are known in Paleozoic genera. ;
“Another type of spines occurs as part of the structures known as ‘paxille.’ Each paxilla consists of a thick plate supporting a number of short, calcareous pillars, the summit of each of which is covered by a group of small spines. Insome Phanerozonia * * * thepaxille occupy almost the whole abactinal surface of the Asteroid”? (Gregory 1900, p. 247).
Pedicellariz.
Pincer or scissors-like calcareous appendages, attached to the spines, the plates,
or the skin, which keep the body-wall clean of parasites. None have as yet
REVISION OF PALEOZOIC STELLEROIDEA. 1%
been detected with certainty in Paleozoic genera. In the primitive Recent forms they are also absent, the integument being protected by an abundance of closely set spines.
“The Pedicellarize of Asteroids are of four main types. The simplest form con- sists of a row of pairs of small, sessile, opposable spines; these are the ‘ pseudo- pedicellarize.? The members of the second set are ‘sessile.’ The next advance is the development of a stalk; of these pedunculate pedicellariz there are two varieties: (1) the ‘forficiform,’ in which the two hooks are attached to the near-
est end of the basal plate nearest to them; (2) the ‘forcipiform,’ in which the two hooks cross one another and are attached to the end of the basal plate far- thest from them’’ (Gregory 1900, p. 247; also see Verrill 1914, pp. 25-34).
Perradial.
The area along the center of the rays. The ambulacra are perradial in position,
See Interradial. Plates.
Some writers restrict the term plates to the five primary radials, five interradials, and the central disk piece, and refer to all the other calcareous parts as ossicles. The word plates is here used in the widest sense, and as interchangeable with ossicles. For the sake of brevity the plates will be often referred to as margi- nalia, radialia, etc.
Podial openings. The rounded openings between the ambulacral plates for the protrusion of the locomotor organs, the podia or water-tube-feet. See also Ambulacral. Primary radial. See Radial. Primary skeleton.
The skeleton of a starfish is made up of primary and secondary ossicles. The primary skeleton consists of the longest inherited and the first appearing plates in the young, as the ambulacral, adambulacral, marginal and radial columns, plus the primary pieces of the disk. All the other ossicles inserted between these are of the secondary skeleton.
Radial.
Refers only to the prominent abactinal primary plates holding a radial position. Where present, they form columns of continuous reticular or separated radialia, situated along the radial center of the rays. Proximal radials are those on or near the disk and should not be confounded with the primary radials, the probable homologues of the radials in crinids. These plates are also known as median dorsals, dorsals or carinals; also as radialia.
Rays.
The radial ‘‘arms”’ of starfishes. These are hollow and contain the digestive, reproductive, and water-vascular systems and other organs. The rays merge gradually and without sharp demarcation into the central disk.
Respiratory pores.
See Cexcal pores. Secondary skeleton.
See Primary skeleton and Accessory plates. Spines. -
See Pavillz and Pedicellariz. Supramarginal.
See Marginal plates. Terminals.
See Ocular plate.
18 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Torus.
See Oral armature. Trivium.
See Bivium. Vertebral ossicles.
In the Ophiuroidea each pair of adjoining ambulacralia is united into a single plate, the vertebra of the arms. As the arms are very flexible, these ossicles articulate upon one another as do the bones in the vertebral column of verte- brates.
FINDING LIST OF PALEOZOIC STELLEROIDEA.
Page.
Acroura (Ophiura) schlotheimii Mister. Known to the writer only from the list in Woodward, Geol. Mag., dec. 2, vol. 1, 1874, p. 7. Siluric.
Monlmaster! SCHON OFi wa cec.cce acto ainte site ain reer ee eer 131 PAI SOTGNGIS SCHOUGOL = ccm enya oer ares eyea'e a nates les ore eee oer 132 Ainiermedis Schond orf. - 92.0 soe Ne ee taieie eres eta = Pee eee elton as eee 133 Axvnivellensis SchOndorises. 6. 4s). Detiae eo see ses ee eet eee te ele crete arene 132 Aganaster Millerand Gurley 2220: 2.585 2 os a ae eee see 263 AN oreqamus. (Neck and, WOLtnen)) tse ce ne eleternre hin arte terete orate eerie etees 264 A. (?) sp. Miller and Gurley=Lapworthura (?) sp......--------------+---+----- 251 Wiepidaster’ Meeks. se v.nc.5- sonia so eee aie aera ee 228 A. flecuosus (Miller and Dyer)... 22-22-2222 2222 J2tin5 S222 S52 ye te se oe eee = 231 VA ORGY ergis( Meelis) cea meec mone sem ene eite aero eae eet eee oie errr 230 An iqnegarius Meek—Aganaster gregarius.. 02020 one-one = ne ee ieee 264 Arruanniensis (NOME) aon 2sr. == leas tine ese ne lee eee er aa ee 233 9A. WP MEW. BPEClES = 2s. ole oats hiete eis eee ee wpa ere ie 230 IAMIOTtHAStEE, DE Ws FCIIUS so ate nestor ate tala an = rad = alten aera ear ae ea ath teh ree 125 Asmiuamvucnsis (Miller) s.2. 2.22 22 Bes aes ssc ce is dine arte steatene = ala eee reere eee Archeasterias Miiller=X. phen LAE ENSUE I Lees Os ay EEO GA EVER ae CCR Ce ear 129 PAreaster Hall=Mesopalxaster. 7). iii. (ee ois). aie es alee See eee ee 74 A. antiqua Gregory = Mesopaleaster (?) antiquus ....--.----------------------- 86 Aspidosoma Goldiuss—2Linerinaster.-...2-- 22 S22 2s ees Se eerie 241 Avarnotd: Goldfiuss=Enerinaster arnoldt. 22252222523. See ee ee 243 A. eifelense Schéndorf=Enerinasier evfelensis -.. 222... 2222-235. 12 2-22 ee 244 A. goldfussi Schéndorf=Encrinaster goldfusst ...........-.----+++---+++--++-+--- 243 AS graye Speucer—Lnerinaster (?) graye: .< 25. eee 2 Soe oe eee eee 245 A. petaloides Simonovitsch=Encrinaster petaloides.......----------+-+-++-+----- 248 A. petaloides goslariensis Halfar=Encrinaster petaloides goslantensis Seat: ees 243 A.? pontis Clarke=Encrinaster pontig.....-.---.--2+2-2+++0+202220- 225222 eee 244 A. roemeri Schéndorf=Encrinaster roemert.......2--2-- 2022-2002 eee ee eee eee 244 Avvschmiah Schondori=Lncrinaster schmidtt.. c.52 2 es se ee ee 244 A. tischbeinianum Roemer=Encrinaster tischbeinianus.........---+-++--++-+++--- 244 Asterias Graham, Anthony, and James=Petraster (?) americanus....-.-.----- 146 A. acuminatus Simonovitsch= Mesopaleaster (?) acwminatus.......----------- 93 A. anthonti Dana=Petraster (?) americanus. .\. <<. - 22a. eee eee 2 eee 146 A. antiqua Hisinger=Lindstrémaster antiquus......---------+-+-+-0-2+ eee eee 149 A. antiqua Troost= Mesopalzaster (?) antiquus....-.-.-.-.------------ 56-2 86 A. antiquata Locke=Promopalxaster spectOsus.......---.---+---s-see-reee ere 109 A. asperula Roemer= Urasterella asperula.......--.-2---------- + 2-22-22 o==> 188 A. asperula Roemer (part)—Holuidia dechent. .....2 2 2.-2- 0 << foes ee A. constellata Thorent= Urasterella (?) constellata...........-.+.+...-.-+++---- 187 A. matutina Hall= Hudsonagier matutinus......--.-- 22 << 2-2 a ea= fe 57 A. montanus Stschurowsky= Urasterella montand......--..----+-+-+-+++++-+---- 189 A. primexva Salter and Sowerby =Stenaster (?) obtusus.....--.-----+-+-+--++-++--- 167
REVISION OF PALEOZOIC STELLEROIDEA.
Asterias primordialis Anon.=Promopalzaster, sp. undet......-..-.------------ A. (Archexasterias) rhenana Miiller=X enaster (?) rhenanus..........-.+-+-+----- A. spinosissima Roemer. An unsolved starfish from the Lower Devonic of Bundenbach, Germany. See Roemer, Paleeontographica, vol. 9, 1863, p. 147, pl. 29, fig. 4; and Schéndorf, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 33. A. sp. undet. Hall 1847=Celaster tenwiradiatus. Asteriscus antiquus Pictet=Lindstrémaster antiquus.......-..-.+-----+-+--+-++-- Rete CONE MN ee te Lae ae ieee sras = ios see ee ee mos wai a a alae PARAUE ) RCRUULEND SLULUA «cc caaveccadceseceease =o-saesees cess: are Perera Ts AGE) eta eer rink alee pets eve oom tn clas sehr icy Sa elo PA SUGTIa Us DACKCL.. 2. anes esters wens 2 Se ae ee a eae ee POUL AI AeGOL TOW PCMUS «saa sae o5c shld hie clans Mieleanwa sb Scciate were He dele os Pam orainreite (CU TNOTOPE) tae ae cnn sun cs Stelstmecies wee oie eas iene sateen eee A. (?) stutchburii (Etheridge) .............-.-2..-2----2-206- Coe eee ee SSOP MDE ESCNIAT RIS ANG Ree tee cae Se tee le Gone yee als oe alg, sony ee BRUCEI OFS SAlLeL: =. oot nots Re rts Se ce eens See vee 3cee PSGMeMmunea JACK 280 cae see op ice atn denies Bees a eee ee eee Bejanny Jackel. .2202 = 222-2 ee ee eee I ne oe Mane eae tees TEAS OCS RV ol] OFS e Wes BSW 10 17a ge ee ep ee ee eee WEE eee ose cee heat adsaiien.c aces bei cee eeni essen ee Se a eee sess BegOnis Suri Z— EF OleZOpMOMYTO OTONGIS << 222 anecese lose sheets oo tse see- Galaster irautscnold—Callidsierelld x. a5 oo cowie n fo 360s oo et tae cam teees C. mirus Trautschold =Calliasterella mira ........--....2000- ee eee eee cece eee ioe Cerra New Maile a. 5-2 ooh anaes obs oe ew Soha geen cence soeleme te mores erat Jaa schOld ), occ. cae ad oe aad aces cc s2 gash oe sccses tals Rens See See OP UEtARLGE SUZ oteeecsc ot 24s can. anes se oe o oe wane eked ee aoe SOO ICUS UUM 1 Seas 2 on wale Saas wacie a's 0G nines sls sateen tae BiGlastorm yy orien and Maller: 2 2.2 oseu 2h sa ite ages oe cee nasties Meepeciiiinns Wortmon and: MiWer = 2.292.262 2e 5. oe ca Weenies tt sone Parag oe oe Biers cer and Derek ——9 Pal tastCh= =e a. 2 5 4.2 ols peters ce eee ae saree geen C. americanus D’Orbigny=Petraster (?) americanus......----------+----++++- C. latiscutatus Sandberger=Spaniaster latiscutatus.. Se figles ay Mae C. tenuiradiatus D’Orbigny, Prodr. de Paleont., vat 4, 1849, 7 22, Boxed on anisolated madreporite described as oreo sp. undet., Hall, Pal. New York, vol. 1, 1847, p. 18, pl. 4, figs. la, 115. Compasaster Worthen and Milleri2222. 2220258 ssh ooe ew cose sc cides: neee ne eyornoce Wwortien and Miller. 52252520 sissies sea sa amesiisies te sstheda wes e ROWS PCGlCNY hacen oe Ge re sa Sos Ss ca Sein caSe ccciedere de ceeenineestabney (Cyabellites copvonariis Uate... 2. 2. =..8 Sees eS ace nce Se nts ade ee es Mees PB GvOMASleL, NOW SODUBs .ccceu nc. ocde = ite 2 idee wn Scie b Seis oak Sekiclsioses chemuUngensis, NOW BPCCleS...-...--- 655.0 ocd. sec ewet sec dn sceesiee semen Se OT TOU AN ox cote aeiee ee es ee ole ocak tans a exes oe suese Rareoepie BECHINAALET SU a Stiltes os< 265 lou oe eae Wade esse seine He lsaeise? - tonite Bo dees Be errr rn eGo ea ce cient des o-.s abe nee cuidde cee ce -sSe eae sole sna aoe IDLE Gg Rg oe pee ee eee ICINIIABLOLIAS ObUTi2s cons oe amare cb cane kage h ete ooce tee tegen Shas ete = SEER MOPUG SUT ioe Sea Sa nab sattus ae Shear dnie weed ead eS nee eres ee S eee menes <8 Echinodiscaster Delage and Hérouard............---.---------+---------- Pomme raactglus (SUULZ) << cccanc aces eWes cede ana see ees ecncie ce eesssenise Echinodiscites Schuchert=Lchinodiscaster . . Echinodiscus Stiirtz—=Lchinodiscaster. . = nina hantele eae eteas EB. multidactylus Stiirtz=Echinodiscaster sinidacn/iis. ea cred tad eer canes Ciaeaa an eal
149 161 161 161 161
72
73
73 254 254 223 223 234 234 235 190 190 190 190 202 202 265 266
95 146
96
192 193 194 274
97 101
98 200 200 200 211 211 211 211 211 211
20 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Page. Behinostella Sttirtzs:..c.2 3.25 bails eee eee eee He eee Be Se eee 212 PES tag uairt: SUAbT os <a. in ce Me SDSS OAR pe NS a OR aed Ghee ee ees 212 Hifelaster SchOndorio::s. 255: (cre) Seay eee a a ee eee 133 i. Jollmanina: SchonGork « -.\..)2 200923 Mile 2 ee Se ie Ne eee eee 134 Hncrinasterdiaeckels 2/2. - 25500 es A eee See Se eee oe 241 Hnerinaster Haeckel (part)—Protasters--s.-2 2.2 eee Foe ee ee 224 E. arnold (Goldiuss) <5. Je¢ 252 5022 Beek as Se ee eee 243 H-ietfelensis\(Schond orf)... 2. 2.5522 Jase SAS sae ea ae ee 244 Ep goldjussy (Schbndort). «.//5ic04-'3- cere tobe i eee ee ae 243 Esloraye (SPENCer)! 22s seo sci ec ak Ses end oes Stent eierel niall = ato = Cees ee 245 Pkpetatoides: (Simonovitseh)22\-G.5562 2-253. ee ee ee Sie ee eee 243 Be netaloides goslariensis.(Haltar) 222 .c8 0225 2 Se sc on - eee oe a 243 We POMS. (Cate \e ihe os ac 8s Bian eta Sie ee ee ee ge 244 IB roement (Schond ori)... ssa ec ot os bs eee 244 BE schonials (SchGndori)sis5. 2.5 065.355 wen = oli ee 244 BE Cischbe mianus (ROCMED))... 25-5 -soece = <= = eee eect es ae eee Soe gee Moactis Spencers See Urasterella: . = oy... .2te ack amen eaee eee eee eae 173 E. simplex Spencer. See Urasterella girvanensis .........--2++-+-+--------0- 186 HMoluigia, Sturtzsssassos ese ee oe sae whit 6, eae 1 A Se a 262 PIPOSCHENT SHULLZE Ss a5 Saeed ce heals Che ee Sacer aan eae ne ei ee 262 Mopiiura Jaokels = cio 32595 22 Se fee ates soe reer eae eras See ee 222 BE UOREMIUCH, DOW BPCCIOS acc. cect ea eel ee Sa ee Ae es ee 222 Bophiurites Sttirtz—Loluidias.is2 22.66. estan aoe es ee Be dechent (Stirtz)—Lolwidia dechent 2-2 oo -sseae H= lee eee eee ae 262 HPospondylus Gregory: tices tansy slr ni poo oe 7 ee eae 263 Brea PTUNUIGENAUSs (iS GUTEZ) bam seek oe nite see maar eral (ere ee Cates 263 Btheridgaster Gregory — Monaster ss. 2- 526s oo gre eee 170 Beclan ken Gregoryi— Monaster Clan helo sea ee = = ei ee ee 172 BIC Agia WOO War S2y:bie asia sia HN Sale icc tsa te SS cate nes eC test ae aeons 276 (2) beecherts Mew Bpecleseal ao: 422.7. 9S) Sees eee eer eit 278 Hegonnsona- Wood Wald a.222. fase es. 585.5 252 ee ee eee Cee 276 E.. woodwardi Sollas.....-. she SSeS SOON ee ea 2 OO Be Seen 277 EBugaster Hall—=Pugasierellas 5.5 52 sega Re a eee eee 237 E. concinnus Ringueberg=LEugasterella (?) concinna..........-.--+------------ 239 EB. logan’ Hall Hugasterella loganite 3 ae Beem aie ae teeter eee 238 Hugasterella, mew name. «2. 20) ek aan ee = ae nee ee ae ct aoceee 237 HN?) concwina (Rimngue berg) 22.22 262 2520 ahs ee eed > eee 239 MOGONAA ELAN Weve nace Se Ge 6 Style nee Sle acts ae eter PSI aes tees 238 Euryale annulatum DeKay. Apparently a lysophiurid. See Hall, Pal. N. Y.,
vol. 3, 1861, p. 184 (nomen nudum).
Euthemon Sollas: ne. /2eoososssse 82 pus e ee ati oc RAE SS ee 279 Meigerna Sollasé x5. 4055 hae ks sds OL See ie SE ee 279 FurcasteriStirtz-..2fs 824 2.2 eet! pes ee ee eee 261 BS. (2) daovlasénsis\(Davy)-2.2-.6 ades2 Saat cen a2 ac sees Soe nena 261 Pi paleozoicus StUrtzis ese oet eset wanes sa amie aii eer ee ee 261 Greroriura, Chapman. 2 42a a5 = cn a= See oe - ee eise ie = i e 233 Gerri Chapmiane:3 2282. oe bodes ies ee se ee ere sere 234 Ballastor StirtZ: 22.52 -ss7ans dees seas ates eee. saeco eee eee 254 ee forbest (Hall):. 2.02’. 21250 ssisae ee se =e OS Rise ee ee 255 Helianthaster Clarke (part)= = Paleosolaster = tee, a daniee Sicie 2 4 Se eee 209 Helianthaster Roemer..5.52-252=- 22h. .5hse asset eee ee 159 Ee filiciformis: Wood wards ..22 35s eis - 34 so ee ee 160 H. gyalum Clarke=Palzxosolaster (?) gyalum-..-.--------------- Lothae Seoulse eae 210
REVISION OF PALEOZOIC STELLEROIDEA. at
Page Helianthaster gyalum Clarke (part)=Lepidasterella babcocki.............------ 160 H., new species Clarke=Lepidasterella babcocki.............2..222-000-0e2 eee 160 ME OTA TS PIN GUAGE: Segre nee aici tots Sear Re Sea aye 5 are ns Ree ae ataes 159 H. roemert Clarke—Palxosolaster roemert............--00----e ee eee eee eeee eee 211 Hisingeraster Stirtz=Lindsirémaster.........-.--.-0-2-- 202 e eee eee eee eee 148 A. antique Stirtz—Lindsiromaster antiquus. ...- 2-22 cane css e eee cece cess ces 149 INTASOTMAS GOT SUIT be ese mace eter ole Se ees le Se irae oe stautcleves 2 Sa 53 em paer?, New Speelcde of. tek Se accaawteeesha say ease tsi eaeeeses 65 DDE TIOT ya FEM QL RST] Se) de a on 61 OSE GURUS FT 9) IE IC 20 a A 57 eM iilene. MGW BPCCICRe des. corres ote a oti aie! S avian ole ihc eee enc owe tne Sea 60 PERRO | PUILOSOL) see sre Sich 5c a0 5 5 ora wc sine nies oe Swine “ne € Sin. myn wsiniains 59 mea OUTTA) fons ast NON crt 2G oA ais ow here be Ft Eins cw Ble shed Pas, dow we 64 Mer ClASbOM OhUTEZ 60 degein seme ee Sane we nessa ae see SA erg Garena aes 192 Se ONS UUs coke ie, tk Sale iid wad Se wo apis Sle Me od 5 eS ops a 192 Reet CEG AC COORY ccc sein sue saan widneresle es Sh 2 8de4 sas 32s ae ke ore 250 eeriondrica Varks— i eniaster CyUNEPiCUS... .. 2.2%. .-5-2-220-5- 222200 Sees 220 Re rr Ol) ee ae ee oe een ca be Sane a a.einiee OMe s 251 ee Te CREE ete on? ake cmc sa tem atic oss sesh ealesaes Dw de tenes 251 JC) | Se ee eee RE AN do Sa salamat A Eaeata aaa 251 Beer teI NOE MBA..g2saecc knoe onipcw twemilencs.s baited ins Wea ad new ncs «Seams 158 POON GEDCS cac5. ec aiets ve os tba Sc bets t doe ete Ree Se, en 158 ees CeL Oe NeW) Pes. «sconce ies ee Set See ses oer a 160 MMITECOCK. Dow APCCICH Stover ee 28s. ot eek ee bar owe oh ie aie cen Ae oe 160 Lindstro6master Gregory........:..--..-- Se Se ye oath 2th eee eee a ee ee 148 er ithe GAICENO OY jon Ser cede Sets See oe sae See eee sade beens eee 149 ETON AS GOT SOU Ula cee ois SS ote tad bois 2a Sie wet nie widieis menialnis ooh se oa ee 201 Peers Mie se bo Oe ete a edhe de cae s Sot bc Sek te es tewe awa 201 PUMA RECOIL ise se Set Sache oak eee at oe ekes ctbes oat ooee 212 ee UN er ee Oe he de dain iota wengeateeeedee ae 212 ECBO EIDASLOR, NOW CONUS. crcs ancecle tie .c:c dnl do a.ciaie do'a.laatoisia a dite ose sc 74 Me 7 ACN alia (WIMONOVIUSCI ) i <cteweeg se con vom ooo eee eee Sea eea ge 93 iM, (2?) aniiquus (Troost) ..-:-...2....2.: Se ee ee ee eee 86 PMerGereirie:( tN laecs ess sccduds kav ack eesti ead hasnt de tec sc08 6 Sees 91 EPEPATOPACIICUCECOOLY jo. ee eee canis Peano 2 eek she luda intee Baws S eee 92 Mes 2) COLaractens(s, NeW SPCCleS: 22. ..2 ons 2 Sos seeds + secs sl denne sce 89 Me?) Cored (Clarke aNd: SWALtZ)..- 2.6 .oehn ec de Soe de ee seve seeeeecnsseese 94 Me (evanous (Maller and: Dyer) 200.225 2e sc ses csessceeckaesdaeeee0csees 85 M. finet (Ulrich).....-- Mae oui ete ton Peas faweds vedas eet 81 MOTH U OCUGE! nce eee areas CS estes cce nse eset aees sasha nd sanesndee eee 89 M. intermedius, new species...........-.---------- EMBs esha catnia ie es 79 (i? \Manccolaius, NOW SPCCICR oo. 22. <.-« Bigs e's dalled cba cect sen nce bee c's 82 rane) Ps ISCILEIES ORs oe oo nk a cenit Merc osteo ba duote deed a cee 87 Mer mrOmiiiie, NOW SPOClOS..- 222-02. seeoc ss adae noe ocke ce cescesactes taweuese 83 EMAIL ChE LIAN UN oe a aster tye ke os 2d Ahi Savon de sts a loudesteees Se baes 77 M_i(7)lberanus (Meek and Worthen)........ 2.02.25 0 2.--- 00 eee sceseeesneee 84. Mage FOTOS CHOUCON eer sien deeded oc ecs esate eee ee tec ere ed coon me 96 ME TOVeRM AIRY SCHOMMOE taiji Sia Se ale seed oes owe coe ee eee 96 nee MAO WLS CROP ONY 0c ks Serva genione cds cesta cereve cnn Bar Ved aoe ena, 263 ESA BCE IS GUCCI a 02) ae ae ae EN re ne 263 pecs COM PE NOLIGY Gs 9- wie ee eats celle Sabon! ote as to baie SU sit conmwareds 170 Beonasver Grerory —Avsiralaster. «ssc tveieines do Uke a Xe clee Se cmesce du Sees eaued 72
PME CEs Reo (MGA NG MTMIUC Hs) ees sec Neo tay a SS varcn nya SR feteenntad senses ane d POS wna h de So 172
22 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Page.
Monaster giganteus Etheridge=Australaster giganteus ........-...-.---.-.---- 73 M. stutchburti Etheridge=Australaster stutchburii.........-..--..------------- 73 Neopalseaster, Ne weeMUSs -)s scans sce s ysieeieinc bce ee ene cise ete re oe eee 134 Necrawmjordsvitlensts (Maller) xcs s-~002 oc toes eee See ees Gh (Ruane ee 136 Onychaster Meck and Worthen: ...% 222.) Se eke eee eee eee 268 Osasper Maller: . choose bebe sR eRe sal stags oe win ote See 272 OX barrist (Hall) icin os 2 se hs we ee cierto dOisteaie eee Se 2 eee 272 Oxconjragosus Miller's: vcisssci5- soe cce oe tee oaks ca ade Oe eee 273 O. demissus Miller.......... Cea goad Sa Sie ee SI hae te eee 274 Osflesilis Meek-and Worthen =. 5 he) sts 0. Sahat sets aie Ne ea 270 Ophiopese Bohm—Aganaster. 2: ssh c5 sc. 52s siwick 1a Gee esc assa so usee atee 263 Ophiura obtusa Eichwald=Protaster (Ophiura) obtusus. O. (?) ramosa Fahrenkohle. Unknown to writer. See Bull. Soc. Imp. Nat.
Moscow, n. ser., vol. 17, 1844, p. 208, pl. 3, figs. 1-3; and Woodward, Geol.
Mag., dec. 2, vol. 1, 1874, p. 7 (listed only). Coal Measures. OF rhenana Stirtz— Mospondylus rhenanus 552 os ac nae ee eee eee 263 0. saltern'Salter.and: Sowerby —Protaster (2) saltem.. 2-292 22-2s seens essen 227 O. schlotheimui Miinster= Acroura (Ophiura) schlotheimi. Gphiuroella Stirtz—Lospondylus:< 32s. 92s shies Saeses see eee see eee 263 O. primigenia Stiirtz—Hospondylus primigenius.......-...---2-2-+-----+----- 263 Ophiurina SturtZ. sc. os. Sco sso sw. ct eee ce wet's 2s Ose a caule de eee eee eener 246 Os mants Stiinta owe Be a oe cc asa sabes ene ses oete nee tae C seen ece eee 247 Palmasterd4allinn soo cske te dens enccine eon a eae eae eae ae 67 Paleaster of authors=Hudsonaster, Mesopalxaster, Devonaster, Promopal-
xaster, Anorthaster, Neopalxaster, Petraster, Palasterina, Monaster, Uras-
terella. Paleaster (Monaster) Etheridge= Monaster..............-----+------------ 170 Palzaster (Monaster) Etheridge (part)=Australaster..:.......--..-.------- hz P. (Argaster) antiqua Hall= Mesopalzxaster (?) antiquus ........--.--.-/-.------ 86 Prantquatus Hall—Promopalxaster speciosus .. 2 525222222226 == ee ee ee 109 Pantiquus Miller— Meso palxaster (?) antiquus =22 522 5.us4- 6-3 a bee 86 Pasperrime Salter— Urasterella (?) asperruma,.. ....<-!--= sie ce ae 187 P. caractacit Salter= Meso palxaster caractact ..........--.-- «sree pa eee cee 92 P; clarkana Miller=Hudsonaster incomptus 2... oc. scien se ee 61 P. clarke: De: Koninck= Monaster clarke). 4.0525 5.5. 22-2) -p ee tee ee 172 iP clarker Miller=Hudsonaster, incomptuss-22. =. /2)--1. 5-2) ee el ee ee 61 P. clarki Clarke and Swartz= Mesopalexaster (?) clarki........-..--.------------ 94 P. coronella Salter—Stenaster (?) coronella...........------------ Soe 167 P. crawfordsvillensis Miller=Neopalxaster crawfordsvillensis......-..---------- 136 P. dubius Miller and Dyer= Mesopalzaster (?) dubius ........-.---------------- 85 P dyer. Meek—Promopalgaster dyert...<= 2 -< 222 26> ==. 5c oe eee ee aa ee 120 P. eucharis Hatl=Devonaster ewcharis..........-.000200200e002ee eee cece eens 98 Pexculptus’ Miller—Promopalwaster. exculptus.....-- 2. 2-0 eee 117 P finer Wirich = Meso pal aster finer. 2-2 scene = oe ee 81 P. (Monaster) giganteus Etheridge=Australaster giganteus........-..------+-+--- 73 P: granit Spencer= Mesopaleaster granti. 22... tse ce tse -anee ee ele ee 89 P; granulosus Hall=Promopalxaster granwlosus...---. +... 2. -2-2-2ses8 eee 112 P. granulosus Meek=Promopalxaster speciosus.......--------+-----+---+++-+-- 109 PE harrist Miller= Urasteretla grandis): «<<seme-2-= 522 Jose ea 2 aoe eee 180 Phisudo Salter= Urasterella hirudo ses. /220 eS. oo seen =e ee Se 188 P. imbricatus Salter= Tetraster (?) imbricatus.......-------+-- as SR ae 169 P. incomptus Meek= Hudsonaster incomptus......--.-------+--+-+----+2-+--- 61 P. jamest Hall=Petraster (?) americanus’ 2... 020. 02 see-saw tense eens e eee 146
REVISION OF PALEOZOIC STELLEROIDEA. 23
Page. Palzxaster longibrachiatus Miller=Promopalxaster spinulosus .........-.-..----- 115 P. magnificus Miller=Promopalxaster magnificus.........-.-..+22+222202020-- 122 P. matutinus Hall=Hudsonaster matutinus...........------------- 2-2 ee eee eee 57 P. miamiensis Miller=Anorthaster miamiensis..............--0000-2-22200 eee 127 P. montanus Trautschold= Urasterella montana.........--.------------+-+++---- 189 emg UE CRS SUA oe ca ein cee ea cite aetna on a ak emda aie dad SEaSe 69 P. obtusus Salter=Stenaster (?) obtusus........- Pees ee ALO ’ P. parviusculus Billings= Mesopalzaster (?) parvinse ulus. ie een Paes pea ea 87 P. pulchellus Billings= Urasterella pulchella..........2.-.-022- 2-0 e eee cece eee 178 P. pygmxa Eichwald. Not known to writer. Middle Ordovicic, Pulkowa, . Russia, iE a TUuLnvend malver— UTOSLeTEUG TULNUCNY «a. cccene= idee less doeceseccscteneedes 187 P. shaffert Hall= Mesopaleaster shaffert....... 22-02-0200. e eee eee eee meer fii P. simplex Miller and Dyer=Hudsonaster incomptus.........-------------++--- 61 P., speciosus Meek=Promopalexaster speciosus.........-...2---+-----0-e-2222- 109 P. spinulosus Miller and Dyer=Promopalzxaster spinulosus........-.-- 115 P. squamatus Salter. Not known to writer. See Cat. Woodwardian Mus., | 1873, p. 47; and Woodward, Geol. Mag., dec. 2, vol. 1, 1874, p. 7 (listed erly). Bala of England. P. (Monaster) stutchburti Etheridge=Australaster (?) stutchburti..........-.---- 73 P. wilberanus Hall= Mesopalexaster (?) wilberanus..........---+-----0-200++-- 84 P. ? wilsont Raymond=Promopalexaster wilsont.....--.....-222-2222--222222-- 106 P. wykoffi Miller and Gurley=Promopalxaster as u: eee eer 119 Palsoasterina Grecory—Palasterind....cserseccrcess sc eece ee ec eseeesceseeae 150 Palzoasterina of authors Petraster ic cedee sen dose esses ce edsedeceeeseee es 138 P. antiqua Salter=Lindstrémaster antiquus........-... 2... eee eee eee eee eee 149 P. approximata Miller and Dyer=Petraster speciosus.......--.----------------- 142 P. fimbriata Meek and Worthen=Schenaster fimbriatus...........-.-.2+--+-+-- 204 rugosa Billings Hudsonaster Mugosus 2.2 .--2ecescns eee ee ese cencnese sees 64 P. speciosa Miller and Dyer=FPetraster speciosus......-..-----------+-++-+--+---- 142 IpatrOneChia, SUUTLZ—) ML LOStCN =. nec adctsinne coe ose Ssa Se eee e oecscemceec= doo Eeachonicn sturia—F alvostelld solide. so ese sso eset eee vi Pek aileeke 156 ipaimocoma Miller (part) —Pinlonaster .o222 2 hos sss doles c cece Sessa 239 Palsocoma Salter—Ouirizester caso. os «cos ead ece es lee ee li sed ewes lati eest 252 Paleeocoma (Bdellacoma) Salter=Bdellacoma.............-...-.-----+-+--- 254 Palzeocoma (Rhopalocoma) Salter=Rhopalocoma........-...--....--------- 254 eRCOID IT ORLOl——SLUTECOSLET COMUIN oc cn cognads dock cue hed cea eeee nookee ee uses 253 eSCUONIPES DALLCl =O LUurlZaster CYGNIPES: J. o2cee = Soe lw Pew one she Goon oo5 eb See 253 P. cylindrica Billings=Tzniaster cylindricus.........---------- 2-2 - ee eee eee eee 220 Pe marsionz Salter=Stiirizaster Marston’... 2. 2 oe ees ote be oe eee e cess sees ene 253 aprucens Miller=Prilonaster princeps.. 2.0. <2 be 2 see ciee dee ces Senos seca 240 P. pyrotechnica Salter=Rhopalocoma pyrotechnica .....-------+++-+------e22e-- 254 Paspinosa Dillinos—= Teeniaster SPiNOSus cncacoe seen vcincsic coc secrcsies annisieesss 219 P. vermiformis Salter=Bdellacoma vermiformis.......-.2000-eee eee eee c eee ees 254 Palzxodiscus ferox Salter=an echinid. See Jackson, Mem. Boston Soc. Nat. Hist., vol. 7, 1912, p. 250. ae O PINOy Re SOUT Sho i a 55 oes nos ae eet Mase a dead eek a teens boas 234 PE CPONCIS UW SLUTL ecclesia ae Oe )b «nba cide naredomaendewetind nedneeapdes hin oe 235 eae OMMIUEA, SOUL s2 5 onic Cilciis as a Sahin x os nan aid paca delaseudsscavcde.st<s 235 RMAC INU c aes ool. eee eewas oka od spe Sen Sees Bo sewcah<gibea tae 235 Pee SCLASTOL SULA oe ecw wies secede J~ od daklnotisie ont wae essesteless ace 209 emOTeACr LULL eee oa eae te be ono ne ede Seo e ee eS ere eee ewiat tdaccieyn s 209
Pema OUGLIINE (CLATEO) ena. o tates so dniaS tacts non ere aeic asa at iene ss See endow 2a 210
24 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Page. Palzosolaster voemert,(Clarke)t 213s ck seater eee 211 Paleospondylus stirtz—Palasiropceren. sat ae oe see soe See ee 261 iPS zittel) stiurtz—Palastropecten zitteli.<.. cactasoe eee eee ee 262 Paleostella Stiirtz............- ‘55 spi NESSUS SERS SOE aie aye 155 Be SOUAGSUUTET aia. ose o-< Se Sie oes eichse yao eS Se ee ae 156 Palsespondylus Stiirtz—Palastropecton.- 2.3. 2 - sso ee 261 Pale ura Jackel 2. ciaiscciclcje ginistats -,ceieyh ares a tose 5 2 ny 1e ee eae 223 P. neglecta, NEW- SPECIES. (..... diene sss Seen ee a A Se ete a 223 Palastcracanthion. Stirtz— Unasterella;s22 ss 2 qa ee a eee 173 Palasterina ‘Billings\(part)—Schkuchertials2 2 shee SB ee 195 Palastorim a McCoys .ce ce titass tees aio crs Se hee ERS eee ae ee 150 P. antiqua Salter=Lnndstrémaster antiquus .... 2.200222 tee ee beets eee 149 POON EYT GTOCOTY og:a,oicle bu 3s obey eaaieia= 2k Seafoam eit eee an age 153 P. follmanni Stiirtz—Pseudopalasterina follmanni ..........--.-+-+-+--+-+-+- 157 Pa (2) james: Dana — Petraster (2) ameniconiusy. 222 22 oe eee ene 146 Pakinanant Baily = Uranasteritinahanis2-.382)nd2 oe Be Le ee 155 iP eprunweua: (HP Orbes) 33. {nesta ee ts oe as ele SS a enc 153 PWG?) ramseyensis Hicks.) tse ba ee ee BI SERIE «a A ee ee 154 Prd Billings==Petrastermgidus: == 5. oe 2. gases eee eee ee 141 Pa rugosa, pillinos— Hudsonasterirugosiseensa 35. eo oes ae eee ee 64 de ustellata, Bullines—Sehuchertya stellata. eet. <2 oe ee ee ee 196 Palasteriscus(Sturtz. 1 Fsk.. co. cece ska ee Skee en ee ee eee eee 200 UP SOLVONICUS SUUTUA 2 oie o.2. 5 ows alo sroy sod cle Hoe oes Seine ol ate ge ee Rone 200 Palastropecten Stlirtz. s...ctacki aoa. c alee ee ee “Aigo Baa ge ates 261 FeV QUE OU SUULUZ: isidicin id's sfelcinlcidistaleretisusn asic etviniotsias aS ee See ee ae ee ee 262 Palmipes antiqua Forbes=Lindstromaster antiquus........--.---------------- 149 Petraster Dillinpse sce jegiecice Saas AS eee eae cee ees 138 IPA? americanus (Di Orbiony avis s2ss82 Bae eee oe ee eee 146 P. (?) antiqua Shumard= Mesopalzaster (?) antiquus.....-.-.-.-------------- 86 Po bellulus Billings—Mesopaleaster bellulus 2 --22ce-m-= aa See eee 91 PE SRIOIIS (CUMIN OS) 18. ce eines eiciemieioais Seite ee noi tan ces er ee 141 P. rigidus (Billings) (part)=Hudsonaster matutinus .......-...--.---------+--- 57 PSM Y Lat MC COV. with icsilis.c ike Sie wehee ie clef eu aioie Deere a Se ae eee ae 147 iPeispeciosus,( Maller and ‘Diyer) 3 5c sciatic ye eee 142 P. wilberianus Meek and Worthen= Mesopalzaster (?) wilberanus.....-.-----+-- 84 Promopalsaster, new |PeCNUs:. esac claisis ia toei fale chs oe eee ne 102 PP bellailinss Wow SPOCLOS salsa sc.2¢ san acral ei a eae pe a 113 Pe duenits (MGC) S =e asthe cus cpecyvuc eiatalaeyne a rays ci ors ees ci Sila RI ANS ere hc ee 120 iP erculptis (Maer) eo 5/52 aire es a al Raps ete yee, ons bee Ly Prgranulosis (Hall) Pts. oe Bead scien ee ea ete CORES Lee eee 112 Pimagnifieus. (Miller). i <.c¢\. geeanee cine c oo de SECS eee oe eee 122 P. WTeNUNTUS; MEW BPCClES! 6 = .- mic Selec athe dae O tere ee eee 107 iP speciosus (Meek). .2.ccc- 5 oth dcut o etic Se sie oee SE ene eee 109 Ps Bp. MNEs 5 etic oles ce esers coe SOE. OS oe eee ete 108 P. spinulosus;(Miller-and Dyer) 02: S22 225 seas, I See ee ee 115 iP .wilsond: (Raymond). <. 8.5.95. jase eenl eee Osa. 2 oe ciaten eee eee eee 106 RB conkopi (Millerand Gurley) s.j.06-scns4eo- oo - =e sae ee ee cago 119 Protaster Horbes..< sh2c%mies.ce sen s-paeeeceeee ++ e eee ees eee 224 Protaster Hall— Hallaster.... «\. \.Se...ce05-2% 2s nies eee es 254 Pi? barrist Hall =Onychaster barns. ..<.25-.2- Sbas eeee eee 272 FE ADU Oris; GReGOLy 2x ,. 2 ks ee ae wie Nadine aoe oe eee 226 P. brisingoides Gregory —Sturtzura brisingoides... .. 2 - = a2) s a= o ee 236 P. daoulasensis Davy=Fircaster (?) daowlasensis. .......0< -- -...nis Jae = eee 261
REVISION OF PALEOZOIC STELLEROIDEA. 95
Page.
Protaster decheni Dewalque= Tremataster (?) decheni.............-..-2-+-++--- 248 P elegans Parks= Tweniaster elegans... 2.2.5... c cece cece eee eee e ee neene 221 P. flecuosus Miller and Dyer=Alepidaster flecuosus......-..--.--22-------+---- 281 Py yorves:. Hall Hallaster forvest....<oxcnccsiccen yececncendt sose ee ceeneceseces 255 P. (?) granuliferus Meek=Alepidaster granuliferus..........2-2-222+2++-222-2-- 230 P. (?) gregarius Meek and Worthen= Aganaster gregarius.........-.....-+++-+-- 264 Ps CRSSTO) UTI 06 110) 121: a 220 P. leptosoma Salter=Stirtzura leptosoma....-.....-22-----20ee eee cece eee eee 237 P. miamiensis Miller=Alepidaster miamiensis.........-.------20--2022222000-- 233 Pemiltont Salter—Lapworthura milion. .... 22... 2-220 -- 0c sce c es sec esen eens 251 P. (Ophiura) obtusus Eichwald. Unknown tothe writer. See Schichtensystem
Esthland, p. 193; Lethza Rossica, p. 661; and Woodward, Geol. Mag., dec.
2, vol. 1, 1874, p. 7 (listed only). Siluric of Russia. P. petriSalter. Unknown tothe writer. See Salter, Cat. Mus. Pract. Geol., p. 30;
and Woodward, Geol. Mag., dec. 2, vol. 1, 1874, p. 7 (listed only). Probably
Bala, Church Stretton, England. Mme MTC OSLLCE bees ae eee yes eee er on hoes cet he eed ook aped wees 227 emeeIeD eM GLDCd whaccs ees hese. coo RL ee eke Seems eee ndeeee ee 225 ete heieliiger RMMSUCDEIO. 2-222. ete cio os See See Sree ees Ws bate bee te 228 DCAM TUG TIT CL TEE 38 d ee ee 227 Protasteracanthion Stiirtz= Urasterella.......0.2. 00022002 c eee eee eee ee Lee P. primus Stirtz= Urasterella asperula..........---.------+-+----- CPe ee 188 Protasterina Ulrich=Alepidaster..........-..-- beg ial en Os AA ea 228 P. jinbriata Ulrich=Aleprdaster fleruosus....c2.0s0ncecdenccccccses es ceseccccs 231 ieruosa James—Alepidaster JleGuOsus. 502-224 seins Dieses ces foes oS 5s ee we ace 231 Protoeuryale C. F. Roemer=a crinid. Protopaicaster Hudson— Hudsonaster ...scc0cec0ce cas ck occa dence edseess 53 P., caractact Spencer= Mesopalxaster caractact.....-.....--------+-eee- eee eee 92 P. narrawayt Hudson= Hudsonaster narrawayt.....------+++----++222 eee eee 59 Bee OP ALAS UCIIINA OO UULUA..c: ccinwen oleae s bees ee rape ai =o 2h =e eid Se Syste wees 156 Mem UMA SOULE) cena 22S ec s @ eyes 5 ae ge yee oo ee 157 PEt Corletss GC Taek cll emer eee yeast eee ae eames ee oe. aoe ae ee is Sees 239 em Utee LAN eeime tee rate een tok ts a ae Cale git asta. Sem plecleas5 Pais See a 240 HP eTIAS Ce SCHONGON 222 528.5 ncn anceps ptes soc Soe vote wade soeeee ee Lees 133 PRC erde SCHONGOM. - 5055+ haFopae se doke ce ot cose nd podem nag oes eos shes sian 133 Rhodostoma Sollas and Sollas=Stiirtzura ......-.-..---.-22-02002 2-02 eee 236 R. leptosoma Sollas and Sollas=Stiirtzura leptosoma...........--.------++-+++- 237 UH OP AIOCOIMG GUINLCD. cc ssbeceedecnts ena teceececsentgenialiwceshaddecgaccs | ZOE ee GUCOTNCH, AAD CV eos 5.5 aS Se wiale ciaa.c lore sheets anne oma ate a ele See aed Ome 254 OCTMICrASber OblrtZ— UTOSIETCl IOs ax ews dos soc wities Sash se setae waes (eects 173 R. (?) acuminatus Stiirtz= Mesopalezaster (?) acuminatus.........----+-+-++-+++-- 93 truce peruia olurta—= Urasteretla Osperila. cc. ccc ose oct wis id da sees cee ee ete oe 188 BI beraster S6UltA— UT OSICrOl ccc s ames sn soos san t's sees sew dad eee eecet ee 173 Saasperrimus Sturtiz— Urasteretla (7) asperrvma...... . 02.02 se. 02-02 se ceweseses 187 Benconaster Meekand Worthen... ... 5002 dc enlace es oes ws ae cen deeueneaseen 202 Se pnuriatie Wieck Ad WOMEN). 2.25. cea see edict aca nesiget eee ete mace 204 oir). vegrandensia Miller and GUICY 2.00.62. ee win ee a snes sce eo aeiee scien aeleine 206 Pant) ORIG SM AVINONGh owe eh a tok dcms coe ae ame sald ct wit wa aie cea coee sie 207 RTO WE SDC COsere ne 2 te en ier oan ek ee es a es Se cieahe ek SIMS eae 206 S. (?) wachsmuthi Meek and Worthen..............----- Oe ea eee = cia 205 BS OLIIIGHL CRE GIG CROCOEY Sone hate adie isa oie ws api ails ada esreeG ab 195 PMC LOLU AMO W RP OCICS ceance ch sce ses. Se ks seh pee te naeeewoeien der oe Secu ts 198
DS MORCIATIA NOW SPCClESis nAcceca bacco es a25e dd 4 oobiel wale sies ay coe! ere 199
26 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Page. Sehuchertia stellata (Billings) 25 .< =< sees = eee are oe = eine eae 196 Siluraster Jackel 2.2224 ee Ee Sa A ee ee ee ee 65 Sper fects Jackel. 5252 GSS Ss RO 9a ae Re Ee ae Satan 66 Spaniaster Schondori-.-22.-5--2- 22-55 - one ee eee = eee 95 Slanseutatus (Sandberger)... 45.4 -sseee ee see See eh cee eee eee 96 Squamaster Ringueberg:--2202 22 soe. sere = ee eee 249 SRCCHINULUS IRIN CUCDEIS no- oc oa .fe ho censenes ee somes oe eee Saat eee 249 Stenaster Billings!) s22..2225 825 -ee =e ee Fees See eee er 163 Stenaster Billines:(part)— Urastereila .-Soesecem seen tee ee ee fe Se?) Con sflivens PranitscHOld s Syocwes lots 2 \s)-c =jcrsiey= tee te Siete ieee et ret eae 167 SAC? reoronelia) (Salter): soee = te.sete esas = ten ie eee creel ee ee 167 Sgrandis: Meek= Urasterella grandis icp ono oh cietcjae em =e eee 180 Slhusleyt Billines— Urasterclla hudleyisy mos se - oe eee ee aa ee 182 SG?) vobtususiGBOrbes) 532 Sacascne. see soe eee et noe ene 167 S. pulchellus Billings= Urasterella pulchella.......-.--.---+---+++-+-+2+-s2-222- 178 MS ee SRLEOR INES Ul bina 9 ye 2 arts lays cs sce eek ates stench eee ees cet apc ee 165 Sturtzastor Wiheridges.-25.-.-- see ee eee ee ee ee 252 SL COLDINE (Sabtel) occa cosas. i sees ea eens seer ee ae ee 253 Sco pesMoalter) es Gye tae eee sae ee bance ta aaa ee ee 253 SS MMOTSLONDMOALLEL) Ua. ese ae Se oe eee a cation es ome se oe ieee eee eee 253 SINC?) mitchell Etheridge: s2 222. e sec). 2s. Sac eeecie Sins ee eee epee ee 254 SturtzunmasGrecory. 22-222 o-oo i. Sse Se we oe = See ey ine eee 236 Subpisingower (Gregory). acc. joins = e's os soe oie ele eels eee 236 Sate PLOSOMMOMSALGEE) ola. o.c20)< cin aie id= 2 3 see eee ee eter eee ree 237 Seileptosomeides Chapman... 4.2 =. <s)c -wisiome sein de = See se Eee 237 Symipterura) Bather. 2525.03. 2 ce ok ssc eee ieee ei eee = ee 256 SRM UEr iD BENGR 2s .vca x See see diane Hee Se oe ee ee eee 256 Pooniaster Billiniga. 2c -).\s.6 < <cjei< Sats = esis se Ae Oe ne eral epee 216 australis McCoy —=Stirtzura brisingoides -..2- on ate see eee or erie = ere 236 Prcyunaricus (Billings). s220-.0.s2 2 2.8 soe slic ee ee ee 220 Rtelegans\Millersos.2 5.262 soeeis sees «8 os ae eee ee CE eee eee 221 a meajordensis Woerstes<2 /2 0.4.2.6 222. gs. 4 thet eee cer eer eee eee 221 Wxschoharie Ruedemann.. och. ous tence Os = Seance es See aeenee 220 im sminosus (Billings) 2.2. .d/scte voces dese des oases hee oe ee 219 Peaaitra, Grecory— IP eniastenes. = 222) secre oe ee ee ee 216 T: cylindrica Gregory= Teniaster cylindricus ..s-225- 22-0. 02- ee eee ee 220 Tétraster Nicholson’and Etheridge: 2202.2: jocjocae eis oe ee ier 167 T. asperrimus Nicholson and Etheridge= Urasterella (?) asperrima......-------- 187 On? ANOTICALILE (ALLEL) J - -~ 2 sais a cicinis a= aitotee eerie alone ayer 169 T. sp. indet. Nicholson and Etheridge= Urasterella girvanensis: .....-.-------- 186 T. wyville-thomsoni Nicholson and Etheridge..........-.--.----------------- 168 T. wyville-thomsoni Nicholson and Etheridge (part)= Hudsonaster bathert...---- 65 Trematasber Worthen and Millers... - 5222-22. i222 <2) eee eee 247 T. (?)-dechent (Dewalque)....-.. 22.0.5 S265 seb oeese ~e tenes 32 eae eee 248 T-dijielis Worthen: and: Miller. 2... < 200. «oman osee eee eee a eee 247 Trentonaster Stiirtz—Schuchertia. 222. <2. ce 1. se ele ads = 195 T. stellata Stirtz—Schuchertia stellata... . 2. -.2222--+-05-22-2---02 ee eeeenee== 196 Trichotaster plumiformis Wright. A 10-rayed asterid from the Wenlock lime- stone at Dudley, England, in the collection of Dr. Grindrod. Insufficiently described to be regarded as defined. See Quart. Journ. Geol. Soc., vol. 29, 1878, p. 421; also Woodward, Geol. Mag., dec. 2, vol. 1, 1874, p. 7 (listed as Trochitaster plumiformis). Trimoeraster Schéndorl.. . sa). 22 2se52~ ee eee eee ee ee 134
Page. TREN AGL DOTUUULS SCNONGOT se 5:5. 6eieicns nice one cetiena staseaess cee sseeeeess 134 Trochitaster plumiformis Wright=Trichotaster plumiformis. aA POET TOPOL Yio. cates. they ass xinle sia sais fa aidaeit-w Hg wieie naly Odie = + a's gee 154 SE ee DONC CN ae eee een ea iin aoe adhais ceeds set anos aan peed eae 155 Pn rereitrto at by, fees meer tas ctel ania BS whe ate a thay 2 gpd os tara in as een ed 155 Uraster hirudo Forbes= Urasterella hirudo.........-..---2-2-----22 eee e eee e eee 188 U. obtusus Forbes=Stenaster (?) obtusus............---.222-2222 ee eee eee eee 167 U. primxvus Forbes=Palasterina primxva....... 2... - +2220 e eee eee eee eee 153 U. ruthvent Forbes= Urasterella ruthvent.........--- 22-2 ee secon cece e eee eee 187 PiPasberela MCCOY co. dos. Booss fo 3 snes. asicciemese SoU ee eens. eee edba cen 173 Urasterella Stiirtz 1893—Sienaster_.-...- 2.22.22. cece ces ects cece eeenene 163 Meee aspera (OMCl nee gah sncatcae se sek al oadoees ses s5.nct teenage. S 187 ae nV OUNICR) coren area n eas ect sab neciec Soe fea ee ew es iGo 5 come: 188 Uy constciiara ( VNOrent)s/-3..22. 22s sree etl. Bae sk oe ee PG 187 Per aihen a DOW BPCCle Hig. Ses iis ee Se asada vada ew sen ba eS sae SEs 186 rie Meri a ace ees Con ae cedenese net awa cwact sins 22, Ee eee 180 SAUL OLD CS) Ste ake cies Sate as re age pend tons nlaiersva) din wD Vine aes Ria ee 188 ei icy MIn GS rd cos Sete ce eae ne tees dsc yedt nas y afeeev eee 182 Prone ( Steen UTOWEKY = 2 eos Se hc ep ew adia este -Deideek age igse 189 Og Gh) Ce Se 189 pr Clea. | WWPS) ae oie o Pc ahold i wees ae oye. 22 Be en oe le 178 I ee arr) CE OL DOS a iiekieo gay oa <ecie sere $s 65.0 Sn cases Geet Shoe nec ees 187 De eMC COW Net ate aetela Late ton asf ee ekraine asa 2 bes am scad cde owe Sean yes 188 Mme aa NeW BPCCIES 2c. oats che ene tee ost ass ao seou ae Seat ates cee Sean 183 CRAs b or MONO WIISCM aac an tens Gocan Soite ena e- a hna poet Wind feo heeeee ae 129 Pa CMON esac amen Nae rece is ocdisais a ned ewke tee te anes 131 DERIINS SSSI 110) 0 (6 (2) se a eee Aver 13k X. ¢ucharis Schondori—Devonaster ewcharts ....- 2.22220 ce cece eccceewcce sees 98 ‘x margaritatus Follmann—=X . elegans «. ...000s occ sn noes cease ede ne cet eses 131 : EX MOTOGMLALUS, DIMOROVITEC Ne csc. cnn oo nigs oe twee Sa gece ts acis towls cbeaees 131 X. margaritatus Simonovitsch (part)=X. dispar and Agalimaster grandis... .. 131, 132 Bammer ernie, (MUNEL) .f)5 a oo Se 2 saath a b= bane vein ete ce wees oe cee ee 131 X. simplex Simonovitsch=Spaniaster latiscutatus............-..-.2+---2---0-- 96
REVISION OF PALEOZOIC STELLEROIDEA, 27
REMARKS ON THE DEVELOPMENT OF PALEOZOIC STELLEROIDEA,
GEOLOGICAL.
Distribution.—This memoir treats of the following Paleozoic
Steileroidea: North Southern or Euro- A
Genera, | Species. mae * | pean mice.
species, | SP&cles. species. FNC) Clif) Co (2 gee 45 110 51 53 6 J MoV bh) Oo (Ree eis Se Ae ek hs en 30 59 18 36 5 Ophinroideares scacs cess o-ceeas cis nosi-se = co yore one 1 5 5 0 0 VOTH esate nso ace seen: eaiae Sate eco cee aeacels 76 174 74 89 lt
28 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Arranged geologically the distribution is as follows: ‘
Lower | Upper onde Siluric. | Devonic.| Carbon- | Carbon- | Permic. 5 iferous. } iferous. BAYSLOT OIG ED = ott ee Oro acti siae ele aiore nie 46 16 36 6 6 0 EATINILOIGCS: eee natsis gs eee one See eee e 15 17 24 3 0 0 Ophiuroidea sens. sac sobre senate es 0 0 0 5 0 0 TOGA chet cone are wires este ae eis eciee ae 61 33 60 14 6 0
Of all of the Paleozoic Stelleroidea (174 species), not a single one is common to North America and Europe. Of genera having specific representation in more than one continent there are the following: Hudsonaster, 5 in America, 1 in Scotland; Mesopalzaster, 13 (7 doubt- ful) in America, 1 in England, ? 1 in Germany; Petraster, 3 in America (1 doubtful), 1 in Australia; Stenaster, 1 in America, ? 1 in Ireland and Wales, ? 1 in England, ? 1 in Russia; Urasterella, 5 in America, 1 in Scotland, ? 1 in Wales, ?1 in France, 2 in Engiand, 1 in Australia, 1 in Germany, 1 in Russia; Palzosolaster, 1 in Germany, ? 1 in America; Protaster, ? 2 in America, 1 in England, 2 (1 doubtful) in Wales; Tremataster, 1 in America, ?1 in Belgium. Of Ophiuroidea, none have wide distribution.
Nearly all of the species have very short geoiogic ranges, but very few occurring in more than a single formation. Mesopalzxaster intermedius ranges from the ? Utica to the Maysvillian, M. shafferi from the Maysvillian to the Richmondian, Alepidaster flecuosus from the basal Edenian to the upper Maysvillian, Hudsonaster incomp- tus from the Edenian into the Richmondian, Promopalzaster mag- nificus and Petraster speciosus from the Maysvillian to the Rich- mondian.
These tables also show that the Ophiuroidea do not begin earlier than the Lower Carboniferous (Burlington) and that the Auluroidea cease to exist after the same period, for none are as yet known in the Upper Carboniferous or Permic. The latter attained their maximum of development in the Siluric and Devonic, with very rapid decline in the Lower Carboniferous.
The great development of Asteroidea in the Ordovicic is due to the marked specific evolution of the genera Mesopalzaster and Promo- paleaster in North America. This knowledge is the result of care- ful work by local collectors in areas abounding in good fossils. On the other hand the marked rise in specific representation in the De- vonic is due to the protracted collecting in the earlier beds of this period, the roofing slates of Bundenbach, Germany.
Preservation and occurrence.—Starfishes are most often preserved in sandstones and mudstones and least often in limestones. The
REVISION OF PALEOZOIC STELLEROIDEA. 29
reason why they occur less frequently in limestones is partially accounted for by the fact that during the weathering process they are almost always ruined. Those found in such deposits nearly always occur in the thin shale partings between the bedded limestones. In coarse sandstones they are less often seen, probably because these sediments are so much moved by the storm waves—action that destroys the skeleton by separating the plates. Unless a starfish is quickly covered by sediment it is sure to be broken up and jumbled into a mass of unrelated ossicles, because the skeletal parts are rarely coossified. Hence the best preserved specimens are found in mud- stones and especially in the fine-grained, somewhat muddy sand- stones. Here they usually occur as fine molds, since all of the calcium carbonate has been dissolved out by the atmospheric waters. Such material is apt to be fairly abundant in individuals, and although a little difficult to study is often well preserved. Its interpretation is dependent on artificial casts or squeezes in wax or gutta-percha. When found in black slates, as at Bundenbach, the skeleton is pre- served in iron pyrite, and even though these sediments have been subjected to mountain making, the specimens can be cleaned me- chanically of the adhering slate. The process is, however, a laborious one and has been successfully used only by Sttirtz and his two prep- arators. Jn the calcareous shales asterids are often well preserved, with the original skeleton more or less permineralized and the ossicles cemented together so that parts of the individuals weather out as free fossils. This is particularly the case in the Richmondian deposits of Ohio and Indiana.
As a rule, starfishes are obtained in single specimens and as acci- dental finds, and for this reason they are among the rarest of known Paleozoic animals; they are the “fancy fossils’ of the local collectors and the ‘‘choice specimens” of the museums. All of this is, however, due to the accident of preservation plus their great destruction through weathering. That starfishes and ophiurids were common, though probably not so abundant as aulurids, is proven when they are located in their entombing sediment and then quarried for. This is best seen in the well-known Lower Devonic slates of Bundenbach, where the quarrying for roofing material has produced as many starfishes as all other localities put together. A great variety has also been secured here, so that it is the only locality and time of which we can say that we know the starfish fauna. The most remarkable starfish find, however, is that made near Saugerties, New York, where over 400 examples of the Middle Devonic Devonaster eucharis were found in a fine-grained, somewhat muddy sandstone, extending over an area of 200 square feet. They occur as natural molds, and as the animals are found closely associated with Grammysia, it is thought that while feeding on these bivalves
30 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
they were suddenly entrapped by the engulfing sand. In the crinid bed of the Keokuk formation at Crawfordsville, Indiana, the ophiurid Onychaster flexilis is also often met with.
Aulurids, although as a rule not well preserved, are probably more often seen than starfishes, and certainly are far more abundant than ophiurids. The latter condition is, however, probably explained by the fact that no ophiurid is known older than the Carboniferous. Of the aulurid Txniaster elegans 31 individuals occur on one small slab. It is probable that if aulurids and asterids were systematically dug for, a far greater harvest would result than that now at hand. Whenever such specimens are found in place, such prospects should be followed up by digging or by prolonged search on the part of the local workers.
It is very seldom that a Paleozoic asterid is so well preserved that all of its parts can be made out, and this is especially true as regards the dorsal side. During the decay of the animals it is probably true that in most cases the individual lies with its ventral side down, and as the soft parts vanish the dorsal skeleton sinks in irregularly over the actinal skeleton. It is the central region of the disk that suffers dismemberment most. Then, as the two sides of the skeleton finally come to be fully compressed, the rays take on an unnaturally great width, so that in many of the fossils preserved in shales the ambulacral furrow is considerably wider than in nature. For these reasons it is often impossible to say whether the ambulacralia are of the opposite or the alternate arrangement, and what was the original structure of the disk and the interambulacral areas.
ASTERID EVOLUTION. GENERAL OBSERVATIONS.
The majority of the starfishes studied by the writer are from the Ordovicic strata of North America. Collectively these show considerable evolution, for at this early time in the history of the earth Phanerozonia, Cryptozonia, and primitive ophiurids (=Aulu- roidea) are present. Even near the base of the Middle Ordovicic the two former groups appear to be equally common, while the aulurids are as a rule rare and small, though there are occasional large ones. Here the primitive phanerozonian asterids are also small, hardly ever exceeding 15 mm. in diameter, while the derived and far more complex Cryptozonia are large, some of them having rays exceeding 50 mm. In the Lower Ordovicic of America no starfishes are known, while the few that have been reported from Great Britain appear to the writer to be from the Middle Ordovicic.
These facts show that in spite of their absence in Lower Ordovicic rocks there must have lived at that time various kinds of starfishes.
4
REVISION OF PALEOZOIC STELLEROIDEA, ot
Not only this, but we may confidently add that the varied organi- zation of those of the Middle Ordovicice proves that there is a long previous history of which paleontology knows nothing. The origin of the Asteroidea goes back in all probability to the Proterozoic, as may be inferred from the eomplex metamorphosis of the starfish larva. In all of the Cambric, however, not a single starfish has been found, and this is the more surprising when one considers the abun- dance of life unearthed from these sediments in so many places throughout the world. This may mean that a preservable starfish skeleton was not evolved until Lower Ordovicic time, where they will surely be found.
The most primitive fossil starfish—Of the Ordovicic starfishes, the genus Hudsonaster is the most primitive, but with the full quota of parts in the primary skeleton that an unmodified or unspecialized starfish must have. Among living starfishes this primitive skeleton is rarely seen, but occurs in Heterasterias volsellata, ‘and in a few other species, especially when young”’ (Verrill 1914: 27). There are other genera with a simpler skeleton (Stenaster and Tetraster), but these are clearly cryptozonian forms that have originated in a phanerozonian stock not unlike Hudsonaster. The oldest Hudsonasters (see plates 1 to 6) are small animals about 10 mm. in diameter, with thick, highly con- vex, closely adjoining plates, all of which are devoid of spines ex- cepting the adambulacrals, which have simple, minute, articulating spines. On the ventral side there are in each radius double columns of rectangular ambulacralia, with the pieces of each ambulacrum arranged opposite to one another, or nearly so. Outside of these are single columns of adambulacralia of about the same number as the ambulacrals; they are, however, somewhat larger and more trans- verse. These are laterally bounded by much larger, highly convex, granulated, very prominent marginals, which, as they border the animals and are simple ossicles (there are not here two superposed marginalia as 1s so common in living forms), are the inframarginal columns. In the axils of the rays lies a single large marginal plate, the axillary, and these occupy the entire interbrachial areas. Around the inner sides of these axillaries the adambulacralia continue, the two basal pieces being the largest and the essential elements of the oral armature. All of the ventral ossicles are, therefore, seen to be of the primary skeleton.
On the dorsal side of Hudsonaster, the rays have medially promi- nent columns of radials, while on each side of these are other columns of thick ossicles, alternating with the radialia, and these are the supramarginals. The former ossicles continue closely adjoining to near the center of the disk, where lies a single large plate usually called in this memoir the central disk plate, or, more rarely, the centro-dorsal. In the same way, the supramarginals abut in the axils upon a single
50601°—Bull, 88—15——3
32 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
large ossicle, the basal supramarginal plate. Itis thought that the ancestors of Hudsonaster had a dorsal disk skeleton made up of a centro-dorsal, a first ring of 5 primordial radials, and a second ring of 10 plates, 5 of which are the second radials, and 5 interradial pieces, the primordial supramarginals. In Hudsonaster, however, some progression has taken place in the disk in the way of increase of size. Therefore additional ossicles of the secondary skeleton have developed to take up this space, these accessory disk pieces being inserted between the centro-dorsal and the first ring of primordial radials. Such a development of a small number of accessory pieces here is a hint of future complexity and the rise of the secondary skel- eton, and we shall see how in later and derived genera their number becomes multitudinous and their places of insertion nearly everywhere in the older portions of the skeleton between the columns of ossicles.
The supramarginals do not margin the animals, but he inside the inframarginals and axillaries which do margin Hudsonaster and most of the Paleozoic asterids.
From Hudsonaster to all other progressive asterids of the Phane- rozonia type, the change lies mainly in the increasing number of the ossicles, relative decrease in the size of the plates, introduction of many new series of accessory pieces, absorption and removal of others, with a marked general tendency to break up the stiff and ponderous inherited skeleton into one of small pieces, thus affording greater flexibility and greater podial strength through the endless duplication of ambulacral parts. These developmental tendencies take place more especially on the dorsal area and are further accent- uated through increase of body cavity, which demands an enlarged skeletal covering. The disk widens, and along with it the proximal parts of the rays, so that interbrachial areas are also affected, until finally in more than one phylum pentagonal asterids result. The interbrachial areas are dorsally increased by the insertion of acces- sory pieces between the infra~ and supramarginalia, and ventrally by the crowding into these areas of, first, the single axillaries, and then more and more of the oldest inframarginals in pairs, assisted also here by the development of accessory ossicles.
Origin of the wriggling type of starfish—From Hudsonaster to the other progressive asterids of the Cryptozonia type the evolutionary tendencies are in the same directions, but here even greater flexibility appears to be the main stimulus. Accordingly, the entire dorsal skel- eton tends to break up into small loosely adjoining pieces and finally even into a spicular spinose mesh. In these forms the ossicles of the primitive columns are no longer discernible as such, and this tendency is very apt to be likewise true of the primordial disk plates. On the ventral side the inframarginals are no longer wholly present as such, but may be here mixed up with the dorsal skeletal complex. How-
REVISION OF PALEOZOIC STELLEROIDEA. ao
ever, some of these plates are at times retained in the interbrachial areas as large pieces, and in many forms they are still to be made out clearly on the sides of the growing distal ends of the rays. Here the inframarginals occur as columns of tiny closely adjoining ossicles situated directly beside the adambulacrals, and in a few cases the whole five primary dorsal columns (one radial, two supramarginal, and two inframarginal) can be made out without any accessory pieces be- tween them. In other words, a Paleozoic cryptozonian may retain the marginals throughout life, but because of their small size and isolation one from another by accessory pieces or because of intense spiculization, they are no longer recognizable as such. The classifica- tory value of the presence or absence of marginalia is discussed else- where (under Cryptozonia), and as the inframarginals are seemingly or actually lost independently in a number of phyla the term is here used as expressive of this condition, and not necessarily of relationship.
Spencer (1914:9) takes up the origin of the wriggling habit from another point of view, that is, from a study of living Stelleroidea as described by MacBride. The former states that the living forms can be grouped into two divisions as follows:
The graspers.—Asteroid forms in which the tube-feet are used for walking, and for grasping and pulling open the bivalve shells of the mollusks upon which they usually feed. The ambulacralia form an arch to take the pull.
The wrigglers.—Ophiuroid forms in which the tube-feet have lost locomotory powers and become much reduced. The animals progress by wriggling movements of the arm, and the ossicles of the ambulacral groove are extensively modified for this pur- pose. The food is pushed into the mouth by the first two pairs of tube-feet, which become considerably enlarged and are known as buccal tentacles.
If we trace the history of the forms backward we find that the difference between them tends to disappear. Both the ‘‘ graspers’’ and the ‘‘ wrigglers’’ descended from a third group, which I call provisionally ‘‘ the primitive Asterozoa.’’
The postulated ‘primitive Asterozoa”’ above referred to are based upon the earliest stages of growth of starfishes, and had the following characters. The animals were attached to the ground by a well- developed, flexible stalk (seen in Asterina and Asterias); the disk was small compared with the five arms. In connection with the water-vascular system there were two series of ossicles, (1) a double column of flooring pieces forming the sides of the ambulacrum, and (2) a paired covering series as a protection to the soft structures under- neath. The podia emerged between the flooring pieces and these at first ‘were arranged not exactly opposite to each other, but slightly alternating, and in consequence we find that both the flooring and covering plates, which are in direct association with the podia, are not exactly opposite, but arranged alternately.”’
34 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
The rays terminated in a single ossicle with an unpaired tube-foot that later developed at its outer end a pigment spot and finally an ce eye.”
At last the animal lost the stalk and moved about freely as the primitive asterozoon. The flooring plates changed into ambulacrala and the roofing plates into adambulacralia, while the tube-feet were used not for grasping and crawling but for passing small particles of food to the mouth.
Fics. 1 AND 2.—VENTRAL AND DORSAL VIEWS OF THEORETIC PHYLEMBRYO OF STELLEROIDEA, INDICATING HOW THE RAYS ARE INTRODUCED. BASED ON HUDSONASTER. Ad, ADAMBULACRALS; Am, AMBULA- CRALS; Az, MARGINAL AXILLARIES; CD,CENTRO-DORSAL; Inf, INFRAMARGINALS; R1,PRIMORDIAL RADIALS: R270 R11, SUBSEQUENT RADIALS; Sm1, DORSAL INTERRADIALS OR PRIMORDIAL SUPRAMARGINALS; Sm2 TO Sm10, SUBSEQUENT SUPRAMARGINALS.
The asterid radicle—Hudsonaster is held to be very near the radicle that gave rise through modification and inheritance to all subsequent Stelleroidea. A study of the various species and specimens of Hud- sonaster, reinforced by the chronogenesis of this genus and the de- velopmental stages in the individuals, which are discernible in the youthful distal ends of the rays when contrasted with the mature proximal region of the same, has led the writer to speculate on the probable skeletal characters of the radicle of the Stelleroidea. An analysis of mature H. matutinus and of half-grown H. incomptus shows that their ancestors must have been devoid of all disk accessory pieces, or for that matter of all secondary ossicles, since it appears that it is on the disk that these plates first arise. Further, the same material indicates that the younger the individual specimen, or the older the species geologically, not only the smaller is the specimen, but the fewer plates has it in any column. As the
REVISION OF PALEOZOIC STELLEROIDEA. 35
ossicles, other than those of the disk, the interbrachial areas, and the accessory pieces, are introduced in all the columns at the distal ends of the rays, we are permitted, in theorizing as to the characters of the radicle, and from what has been learned from Hudsonaster, to elimi- nate all of the rays with their ventral and dorsal ossicles down to the disk. If this is done, there finally results a tiny depressed and mammillated spheroid, made up dorsally of 11 primary plates, and 5 marginal axillaries, and ventrally of a limited number of adambu- lacrals and ambulacrals around the mouth. To make this matter clearer, two diagrams are presented of the probable characters of the direct ancestor of Hudsonaster (see figs. 1 and 2).
By taking away the rays down to near their bases, 1. e., to R2, and correspondingly decreasing the size of the primordial supramarginals, we get the dorsal structure of a late stage of the probable typembryo of the Stelleroidea, as illustrated in fig. 3.
If all of the ray plates are com- pletely removed, we apparently get the typembryo of the class Stelle- roidea, as illustrated in figs. 4 and 5. It should be stated here, how- Fi¢. 3.—DoRsAL VIEW OF THEORETIC TYPEM-
BRYO OF STELLEROIDEA AT THE BEGINNING ever, that the number of the adam- or ray pevetopMeNt. THE PRIMORDIAL SUP- bulacrals and ambulacrals in figure RAMARGINALS HERE HAVE ON EACH SIDE aoa
e * e . BASAL PIECES OF TEN SUPRAMARGINAL COL- Dis entirely conjectural, though UMNS. CD, CENTRO-DORSAL; R1, PRIMORDIAL these plates and those of the mouth Ey R2, SECOND RADIAL; Sml, DORSAL IN-
TERRADIAL OR PRIMORDIAL SUPRAMARGINAL; frame are among the first to develop S2, BEGINNING OF SUPRAMARGINAL COLUMNS. in living forms.
If the developmental views just stated are correct, it follows that the five branches of the water-vascular and nerve rings of the typ- embryo of Stelleroidea grow outward along the radii, developing as they grow the rays or arms with their dorsal and ventral skeletons. In other words, the growing tips of the radii spread outward beyond the disk, and each one gives rise to nine columns of ossicles (one radial, two supramarginal, two inframarginal, two adambulacral and two ambulacral). The radial plates continue as simple columns, while upon the primordial supramarginals and the axillaries rest pairs of columns, the supramarginals and inframarginals, respectively.
In Echini, however, the growing tips of the radii do not spread beyond the disk (apical disk of oculars and genitals) but remain internal and give rise to new ossicles, the ambulacrals (same ossicles in Stelleroidea) and interambulacrals (~adambulacrals of Steller-
36 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
oidea), all of which appear from underneath the ventral edges of the oculars, each plate in turn being pushed orally?.
In any event, whatever the pre-Hudsonaster evolution was, we are on safe ground in indicating what the developmental changes were, starting with this genus. We will not take up all of the skele- tal parts and discuss them in detail, but will attempt only the more essential portions.
Ontogeny.—Ontogenetic stages of development in the ossicles of asterids can readily be made out to some extent in any well pre- served specimen. The variations can best be seen in those forms with the least number of plates and therefore in the more primitive genera. Here all of the primary ossicles are introduced at the tips of the rays in the seven primary columns. The youngest pieces are also the smallest and the simplest. At first they are globular,
Figs. 4 AND 5.—DORSAL AND VENTRAL VIEWS OF THEORETIC TYPEMBRYO OF STELLEROIDEA. A‘, VEN- TRAL OR MARGINAL AXILLARIES OR BASAL INFRAMARGINALS; CD, CENTRO-DORSAL; R, PRIMORDIAL RADIALS; Sm1, DORSAL INTERRADIALS OR PRIMORDIAL SUPRAMARGINALS.
smooth, and loosely adjoining. Tracing them down the columns, the specific characters are seen to develop and finally the basal pieces are found to be the most modified of all. This is particularly true of the dorsal columns where the most ornate plates are the oldest. In the different species of Hudsonaster one can also trace the changes chronogenetically, as for instance in the basal radialia and supra- marginalia. In the oldest species these plates are not at all, or but very slightly stellate, more so in H. incomptus, and most so in the youngest and largest species, 7. rugosus.
In the stocks with more complex skeletons, the ontogenetic varia- tions in the plates can be traced in the same way. However, as these forms almost always have more or less of accessory plates that are introduced nearly throughout the entire skeleton during the juvenile growth and even at maturity, the study is complicated by the inter- mixture of ossicles of varying age.
1 See Jackson, Phylogeny of the Echini, Mem. Boston Soc. Nat. Hist., vol. 7, 1912.
REVISION OF PALEOZOIC STELLEROIDEA. ot
Spinosity can also be studied ontogenetically because the youngest ossicles do not have spines, and when these appear they are smaller and less characterized than the older ones situated in the proximal portions of the columns.
Many of the ontogenetic changes observed by the writer are re- corded throughout this work, and their significance in related species and genera has been made use of in discerning the phylogenetic lines of descent.
Regeneration.—Among living starfishes it is common to regrow arms that have been lost through accidental causes. From the base of the severed ray a new growing tip is established, forming a juvenile arm that gradually grows to full size and assumes mature characteristics. Schéndorf (1909a: 96-97) states that this habit has been pronounced since the Jurassic but that he has failed to find marked regeneration in Paleozoic asterids. He did, how- ever, note partial replacement of minor losses among the Devonic species. Stiirtz, who has handled more Paleozoic asterids than any other paleontologist, also has not noted a single case of marked regeneration. The same is true for the 400 Devonaster eucharis found in a limited area of the Middle Devonic of New York. Clarke, in describing this find (1912: 44-45), however, does note a few specimens ‘‘which show the existence of only four instead of the normal five arms.” These are the only examples of four-rayed Paleozoic starfishes so far recorded.
The writer has also been unable to find a single case of regenera- tion, but in the Middle Ordovicie cryptozonian Urasterella ulrichi he describes a specimen with two normally developed rays and three short stumps. All of the arms are normal for the species, except for the length of three rays and their terminations, which are blunt. (See pl. 29, fig. 1.) It seems to him that this occurrence is not due to the accident of fossilization or weathering, but is an actual case of loss in life with subsequent healing of the wounds, but without regeneration of the lost parts.
During most of the Paleozoic, the starfishes could have had no carnivorous enemies other than the cephalopods; as for marine fishes, the armored Arthrodires did not appear until the Middle Devonic, while the ancient sharks were not common until Lower Carboniferous (Mississippic) time. It is possible that regeneration among the starfishes is connected with the rise of carnivorous ene- mies, but as the habit is so common among living forms it is more probable that this power has always been inherent in the class. Regeneration among the crinids has been noted in several cases where lost distal ends of arms were being replaced by immature growths. Such have been seen in the Lower Carboniferous (Bur- lington and Keokuk formations) of America.
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Number and character of rays.—In the geologically oldest and the most primitive asterids as well there are always 5 rays, no multirayed form being known back of the middle of Siluric time. In the most primitive genus of Phanerozonia, Hudsonaster, the rays are short and stout, there is a large disk without interbrachial arcs, and the skele- ton is simple but ponderous. From this type originate those with 5 slender rays and also forms with more or less large interbrachial arcs, the pentagonal starfishes.
Long, slender, and flexible-rayed genera without marginalia are present as early as the most primitive Phanerozonia, 1.e., as early as the older Middle Ordovicic, indicating that the two main types of asterid development arose still earlier. The same is true for the ophiurid ancestors (Auluroidea). In fact, slender-rayed Crypto- . zonia are more commonly seen in the Middle Ordovicic than are the Phanerozonia.
Multi-rayed Phanerozonia with primitive arm construction appear in the Middle Siluric (Wenlock) in Lemdaster. This genus has rays which are short and stout, reminding one in this respect strongly of the primitive 5-rayed forms. An insufficiently described 10- rayed form (Trichotaster plumiformis) is recorded from the Middle Siluric (Wenlock) of England. In Helianthaster of the Lower Devonic there are from 14 to 16 rays and here they are long and slender, while in the Upper Devonic there is a form with only 11 rays. Lepid- asterella of the Upper Devonic has 24 arms.
All of the multi-rayed Cryptozonia have slender rays and rather large disks. None are older than the Lower Devonic, where Medusaster has from 12 to 15 rays, Echinasterias 25, Paleosolaster 27 to 29 (an Upper Devonic species referred doubtfully to this genus has 24 or 25), Echinostella 28 or 29, and Echinodiscaster 29.
Curiously, no multi-rayed starfish is known in the Paleozoic later than the Devonic. Further, the arms may be either odd or even in number in the same genus or even species. How the living multi- rayed starfishes introduce their rays is explained under Palsosolas- teride (p. 207).
Verrill (1914: 12-17) holds that the multi-rayed forms arose as ‘“¢snorts,’ which have persisted by heredity and natural selection because they were advantageous.” The advantage lay in “the increased number of ambulacral sucker-feet.’’ Most of these forms are now living in shallow water among the rocks exposed to the surf. He states: “This is true of the seven species of Heliaster, with very numerous rays; and of Pycnopodia, with 20 to 24 rays; and of the various shallow-water and littoral species of Solaster and Crossaster, which usually have 9 to 15 rays (rarely 8 or less). It is also true of the numerous 6-rayed species of Asterias, Pisaster, and allied genera.”’
REVISION OF PALEOZOIC STELLEROIDEA. 39
On the other hand, the increase of rays is more probably due “to the advantage gained in holding their food securely, and in opening bivalves, than for holding to the rocks, though both go together.”
“The ability to cling tenaciously to rocks may be perfected in other ways, involving equally an increased number of sucker-feet. This is often attained by lengthening the rays, * * * by crowding the suckers into more than four rows, * * * and by increasing the size and strength of the suckers.”
DEVELOPMENT OF THE PARTs.
Anus.—In all living starfishes the anus apparently lies in the next interradius to the right of the madreporite, or in the direction as the clock goes, but in no Paleozoic asterid is there positive evidence of an anal opening. However, it is extremely rare in these forms to find the disk so well preserved as to make it possible to locate so small anorifice. Incertain specimens of Hudsonaster, immediately adjacent to the centro-dorsal plate, there is an open space that either is the anal opening or where a plate has dropped out in fossilization. Schéndorf has also failed to find this structure in the German Paleo- zoic asterids, but has indicated its probable position in Spaniaster (see fig. 8) and Calliasterella.
Madreporite—In more than half of the Paleozoic asterids the madreporic plate has not been seen. In many cases this is due to the infallen condition of the disk skeleton and the jumbled state of the ossicles; in others it is due to the fact that it is so small as not to be readily distinguished among the mass of other small plates. Finally, a great number of asterids are known only from the actinal side.
The madreporite in size varies from minute to very large and ponderous. It may be round, oval, or many-sided, concave, and depressed beneath the disk pieces, or protruding cone-shaped (Petras- ter). As arule, it is marked by striations that are coarse or very fine, straight or wavy lined, or it may be crenulostriate or with granular surface. In Petraster the surface canals enter into two spirals that carry the water into the stone canal. In living forms with more than six rays there may be two or more madreporites, but in no Paleozoic species has more than one been seen.
In all of the Paleozoic phanerozonians the madreporite appears to be always dorsal in position. In the most primitive genus, [ud- sonaster, the plate may be large and conspicuous or at times can not be made out even when the disk is fairly well preserved. In no Mesopalexaster has this sieve plate been seen, although good speci- mens are at hand, a condition probably due to its small size among the small skeletal pieces of this genus. In Spaniaster it is very small. In Promopalzaster the madreporite is usually conspicuous and large,
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and the same is true for Xenaster and Agalmaster. The plate is also known in Palzaster, Devonaster, Neopalzaster, and Palasterina.
In multi-rayed phanerozonians the madreporite is unknown in Lepidaster and Lepidasterella. In Helianthaster it is large, conspic- uous, and situated on the edge of the disk, more actinal than abac- tinal. On the other hand, in the cryptozonian multi-rayed genera the madreporite is apparently always actinal and more or less large, as in Palzosolaster and Echinodiscaster. This plate is probably also always actinal on large-disked Cryptozonia such as Palasteriscus (plate enormously large), and Cheiropteraster (here small and situ- ated near the mouth).
Among the five-rayed Paleozoic cryptozonians the madreporite is known only in Monaster (large), Urasterella (medium), and Jaekel- aster (small). In all it is always on the abactinal area.
From this evidence we see that in the five-rayed Phanerozonia, forms that are more or less rigid, the madreporite is always on the dorsal or upper side of the animals, this being true for the deeply stellate as well as for the pentagonal species. In the multi-rayed genera, however, there is a marked tendency for this plate to move outward to the edge of the disk. In the five-rayed cryptozonians the madreporite so far as known is always dorsal, but in the large- disked or pentagonal forms and the multi-rayed species this plate is apparently always ventral.
Spencer (1914:35-38) says that ‘‘many Paleozoic Asterozoa do not appear to have a madreporite” and he is ‘inclined to regard this, in these old forms, as usually a primitive feature.” The present writer, it is true, states above that in more than half of the Paleo- zoic asterids the madreporic plate has not been seen. This is due in most cases, however, to poor preservation, and in others to the fact that the plate is so much like the other disk plates as not to be dis- tinguishable from them. Spencer concludes further that it appears that the madreporite originated on the ventral side, or at least was marginal, in the primitive forms, and that it passed over in later Asteroidea to the dorsal side. In Hudsonaster we have the most primitive known starfish, and here in H. incomptus it is a large and conspicuous plate on the abactinal side. Further, the evidence of the Paleozoic starfishes (Phanerozonia), so far as the present writer knows them, is that this plate is always dorsal in position, and he is inclined to the view that all of them had the madreporite, that it originated on this side, and that in later cryptozonian multiradiate forms it moved outward to the margin of the disk or to the actinal surface. In regard to the Auluroidea, the writer has seen the madreporite so rarely that no deductions as to its original position in these forms can be made.
REVISION OF PALEOZOIC STELLEROIDEA. 41
Spinosity.—In general, it can be said that spines are least developed in the heavily plated Phanerozonia, more so in those forms where the dorsal skeleton is made up of small ossicles in abundance, and fully in most of the Cryptozonia stocks.
In primitive Hudsonaster, all of the plates other than the am- bulacrals are more or less well tuberculated, and these granules do not now carry spines, if they ever did. In later forms, however, as Promopaleaster, they may all have borne spines, some of them of large size. Small club-shaped spines occur here in considerable abundance along the sides of the inframarginals and the adambula- crals. In Palzaster there are brushes of delicate spines along the inner edge of the adambulacrals. In Mesopalexaster the ventral spines are better developed, fully so in Promopalzaster, and probably equally so in most post-Ordovicic forms.
Among the primitive cryptozonian genera Stenaster and Tetraster no spines are now seen, but undoubtedly such were present on the actinal side. In Urasterella the entire dorsal skeleton is more or less spinose, consisting of long, nonarticulating, slender rods, the dorsal extensions of the ossicles. In the multi-rayed Cryptozonia of the Devonic, spinosity is at its greatest development in the Paleozoic.
Ambulacralia.—Undoubtedly the most important skeletal parts of the Stelleroidea are the ambulacrals. In general they undergo the least alteration during geologic time of the entire asterid skeleton, and therefore any marked variation must be of broad classificatory value. Schéndorf? is well aware of this fundamental value and has made full use of it in defining his three ‘‘classes,’’ Asteroidea, Aulu- roidea, and Ophiuroidea. In the Asteroidea the ambulacralia of ad- joining columns are nearly always placed directly opposite one another, with the podia issuing through openings that are not in the plates themselves, but laterally between two adjoining ambulacrals and the corresponding adambulacrals. Among the Paleozoic asterids one is not always certain whether the ambulacralia are arranged ‘‘opposite”’ or ‘‘alternate,” because the specimens in nearly all cases have suffered more or less from distortion. In many good specimens they are very slightly alternate, but in all such cases the arrange- ment is said to be alternate. In other fine fossils they are now alternate, but a close study seems to show that originally they were practically opposite in arrangement. On the other hand, certain of the species with wide ambulacral furrows and large ambulacralia, as in Promopalezaster, Anorthaster, and Urasterella, have an alternate arrangement, while in other species of the first and last named genera they are just as certainly opposite. The writer therefore does not
1 Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 206-256; Paleontographica, vol. 57, 1910, pp. 1-56.
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lay much stress upon this feature among the Ordovicic asterids, nor does he regard it even necessarily as of specific value, but in the later Asteroidea the arrangement is always opposite or nearly so. Ver- rill (1914: 20) states that he has noticed the alternate arrangement in living Pycnopodia ‘“‘as an abnormal variation in some of the rays, and also that it may occur from lateral bending.” Evi- dently the alternate disposition is a fixed character among some Ordovicic forms, as in Anorthaster, but more will certainly be dis- covered in these old strata and probably rather among the Crypto- zonia than the Phanerozonia. The writer is led to this view because of the alternate arrangement in many Auluroidea, a subclass of Stelleroidea that seems to have had its origin in some cryptozonian asterid. Out of the Auluroidea with opposite ambulacralia came the Ophiuroidea with their highly modified ambulacrals which are coossified into ‘‘vertebral ossicles.”” In the Auluroidea the arrange- ment of the ambulacrals is either alternate or opposite, but they are never coossified but are so modified as to suggest the Ophiuroidea rather than the Asteroidea. The structure of these plates is de- scribed elsewhere and need not be repeated here.
The ambulacrals are very variable in number throughout the genera. In Hudsonaster, Sienaster, and Tetraster there are as few as 10 in a column, while in Promopaleaster there are certainly 50 and possibly as many as 60. The cryptozonian genus Urasterella has certainly over 100 in a column. In general, these ossicles abut against each other, but in Urasterella and other genera they overlap proximally to a certain extent. As yet the writer has seen no Paleozoic asterid with more than 2 columns of ambulacrals, though in Promopalezaster magnificus the proximal areas of the rays for a short distance have 4 columns of podial openings. Here, however, the ossicles have not yet wedged themselves into 4 columns of ambulacralia.
In shape and surface contour there is also considerable variation among the ambulacralia. In Hudsonaster, Tetraster, and several Devonic genera they are more or less rectangular, either squarish or drawn out laterally. In other forms of Hudsonaster, along with Stenaster and Urasterella, the ossicles are F -shaped, with the lateral shaft thin, thus allowing for large, elongate podial-openings. The more primitive genera have the outer surfaces plain or slightly ridged, while in derived forms like Promopalzaster the ridges are high and straight or have their medial terminations orally directed. In P. magnificus, the ridges in the proximal region are arranged in pairs having the shape of a tuning fork; in P. wykoffi one sees that these ridges approach one another in pairs transitional to their transforma- tion into the tuning-fork form.
REVISION OF PALEOZOIC STELLEROIDEA. 43
Adambulacralia.—Adambulacralia are present in all Stelleroidea. They are best and typically developed in the Asteroidea, more or less modified in the Auluroidea, and completely altered into the thin scalelike side plates of the Ophiuroidea. In number and relative size they vary as do the ambulacralia, being least numerous and largest in the most primitive genera. Originally they probably bore no spines at all, the plates being practically smooth. In Hud- sonaster and most Ordovicic and Siluric, and some Devonie genera, their surfaces are granular to tubercular. These protuberances in the younger genera may have borne small spines, but long before these appeared each adambulacral bore two or more stout or slender, com- paratively long spines along its ambulacral edge.
In most of the Paleozoic genera there are in each column as many adambulacrals as there are ambulacrals, and both series are as a rule arranged opposite one another. In Anorthaster, however, there are fewer and therefore larger adambulacrals than ambulacrals, and these latter ossicles clearly alternate with one another.
In the Phanerozonia the adambulacrals never margin the rays but always lhe inside of the bordering inframarginals. In the Crypto- zonia, however, the adambulacrals margin the animals and here the ossicles are usually small, though at times they are relatively large and make a stout outer skeletal frame as in Stenaster, Tetraster, and Schenaster (?) montanus. The same is true in LEncrinaster of the Auluroidea.
The adambulacrals in probably all the Paleozoic Phanerozonia continue into the oral region and each two adjoining columns meet here in a pair of modified, elongate, pointed pieces, the most promi- nent ossicles of the oral armature. No other skeletal parts lie in front of these oral ossicles except in the phanerozonian Hudsonaster narrawayt (pl. 1, fig. 1) and in the young of the cryptozonian Urasterella ulrichi (pl. 30, fig. 7). Both are primitive forms of their respective phyla and whether these five pieces or tori are to be interpreted as five spines or whether they represent five primi- tive orals is not yet determinable.
Inframarginalia.—In the great majority of Paleozoic Phanero- zonia the inframarginals alone margin the animals, and only in a few forms (Spaniaster, Miomaster, Rhenaster, and Neopaleaster) have the supramarginals moved outward and completely covered the inframarginals, so that the two columns together equally bound the rays and disk. That condition is a peculiarity common to most Paleozoic phanerozonians, while the wholly superposed arrange- ment distinguishes nearly all the Mesozoic, Cenozoic, and Recent genera of the same kind of Asteroidea.
The inframarginals are usually the most conspicuous ossicles of the Paleozoic Phanerozonia, and this is especially true where the
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skeleton is strong and devoid, or nearly so, of accessory ossicles. They are ponderous in Hudsonaster, Paleaster, Australaster, Devon- aster, -Xenaster, Trvmeraster, Petraster, etc. When the smaller accessory plates are introduced, the inframarginals also reduce in size; this development is best seen when passing from the heavily plated Hudsonaster to the more abundantly plated Mesopaleaster and finally Promopaleaster. The next step in this phyletic line would be pronounced a cryptozonian because the infra- and supra- marginals could not be distinguished from the abundance of acces- sory ossicles. In fact, it is not always easy to make out the various categories of plates even in Promopaleaster, and here one must resort at times to a study of the tips of the rays where the seven pri- mordial columns are not yet disturbed by the introduction of accessory pieces.
In primitive Hudsonaster, where the inframarginals are compara- tively very large, there are only half as many of these ossicles as there are of adambulacrals, but in the great majority of Paleozoic genera of Phanerozonia this marked difference tends to be less decided and toward equalization. In certain phyla, as, for instance, from Hudsonaster to Mesopaleaster and Promopaleaster, the equal- ization has gone on rapidly, in fact, in but a short part of Ordovicic time. Jn more conservative stocks, as from Hudsonaster to Devonic Xenaster and Trimeraster, the equalization is far slower, as is seen in the following figures: Hudsonaster, 12 inframarginals and 24 adambulacrals; Zrvmeraster, 14 and 23; and Xenaster, 20 and 32, respectively. In nearly all the genera these columns of plates alter- nate with one another. This of course must be so where the number of ossicles is different in the two columns, and complete alternation is retained even in certain species where the numbers of ossicles are alike, as for instance in Promopalzaster spinulosus. On the other hand, in Mesopalzaster shafferr, where there are 16 inframarginals and 18 adambulacrals, the plates alternate in the proximal half of the ambulacra and are opposite one another distally. A study of the growing ray tips shows that the various ossicles all appear practically of one size and where there are more adambulacrals than inframarginals, the former are crowded orally. The latter develop- ment appears to be the primitive type of growth, but this mode is rapidly changed to one in which the seven columns of primordial ossicles appear in cycles or rings. This type of growth is easily made out in primitive forms such as Hudsonaster and Mesopalezaster, and in some species of Promopalxaster. However, when accessory plates are developed in abundance, and especially in forms where the seven primordial columns of plates remain of one size, their introduction in cycles can only be made out in very young individuals or at the
REVISION OF PALEOZOIC STELLEROIDEA. 45
extreme tips of the rays, conditions not often attained among these fossils.
In the great majority of Paleozoic Phanerozonia the inframar- ginals and adambulacrals he closely adjacent to one another. In typical asterids they are not separated by the introduction of acces- sory interbrachial pieces until in the Devonic. Here in Xenaster and Trimeraster isolated pieces, and finally a column of them, are inserted in the proximal half of the rays. In the large-disked asterids, this separation occurs much earlier, in the Middle Ordovicic in Petraster.
In Paleozoic Phanerozonia where the skeleton is made up of an abundance of more or less equal-sized ossicles, one notices also on the distal portions of the rays a tendency for the inframarginals to appear on the dorsal side and not to remain on the ventral, as in primitive stocks. This alteration brings the adambulacrals to the margin of the rays, and is a hint as to how Phanerozonia gradually change into Cryptozonia. It is best seen in Promopaleaster, Petras- ter, and Mesopalzaster. In Australaster it is a marked feature, in fact, one can say that the distal parts of the rays in that genus are cryptozonian while the bulk of the arms are still phanerozonian. This ontogenetic appearance is in harmony with phylogenetic devel- opment and chronogenesis. The living Echinaster sepositus is in youth also a phanerozonian, but at maturity is a typical cryptozo- nian. In so typical a cryptozonian as Urasterella, one still finds in half-grown. U. ulricht & number of inframarginals in the interradial or axillary areas. The same retention of the first formed inframargin- als is also met with among the multi-rayed Cryptozonia in Helianth- aster, and even among the Auluroidea in Encrinaster.
It has just been pointed out how the inframarginal columns are eliminated as marginal plates. They are not, however, removed from the skeleton in these early forms by resorption or by failure of development, but for want of special growth. In other words, the inframarginals are probably present in all Paleozoic Asteroidea, but because of lack of specialization through the developmental tendency to greater skeletal flexibility, remain small and are lost as such in the mass of the dorsal plates. This apparent elimination of the inframarginals has gone on independently in various stocks as pointed out elsewhere, and therefore the absence of large marginals, either infra- or supramarginals, or both series, is not of ordinal value.
Supramarginalia.—In Hudsonaster the prominent supramarginal plates of the dorsal side are placed decidedly inside of the inframar- ginals, though the former clearly overlap the latter. This primitive position is retained in many Paleozoic genera, and apparently not before the Devonic do these two columns of ossicles come to lic wholly upon one another, and then they together margin the animals.
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It is apparently always a rare condition in the Paleozoic, but as the post-Devonic asterids are as yet little known, we can more accurately say that the modern type of Phanerozonia is unknown before Devonic time. It should be added here that complete superposition of the supra- upon the inframarginalia undoubtedly took place in more than one stock and at different times. Accordingly, to group all asterids with large marginalia into the “order”? Phanerozonia is further proof that these terms cannot be used in the phyletic sense. Phanerozonia and Cryptozonia are, however, of use in a descriptive way.
The supramarginals, and the inframarginals as well, in primitive forms gradually attain larger size down the columns from the tips of the rays toward the disk and mouth. In other words, the older the ossicle in primitive genera, the larger is its size, and in all such forms the pairs of supra- and inframarginal columns terminate in single plates, the primary or basal supramarginals and the primary or basal inframarginals. The latter ossicles in the most primitive genera are situated in the axils of the rays and are therefore also known as axillary marginals, and in the more specialized genera the axillaries and even pairs of inframarginals are crowded orally into the interbrachial areas. The basal supramarginals im primitive forms always occur prominently on the disk, in derived genera they are, however, less conspicuous, and where the disk skeleton is made up of small ossicles, they are generally indistinguishable in the mass of plates.
We have seen that accessory interbrachial plates in some genera are developed between the inframarginals and adambulacrals, and to a greater extent the same is true of the development of ambital accessory pieces between the former columns and the supramarginals. In probably all cases where the rays and disk grow wider the addi- tional space is largely covered in by the development of accessory plates. As it is in the disk area, and therefore necessarily in the basal portion of the rays as well, that the main increase of body extent takes place, here are developed the greatest number of these pieces. Rarely are the ambital accessory pieces crowded in between these columns beyond the proximal third of the rays. This is best seen in Devonaster and Xenaster, but in the large-disked forms, as Petraster, they extend farther out and are present to within the outer third of the rays. Ambital accessory plates may also be present in Mesopaleaster, but are more definitely so in Promopalz- aster (especially in P. magnificus), and in both genera they occur throughout the greater part of the rays.
Radialia.—In many Paleozoic genera of Phanerozonia and even among some of the Cryptozonia, a more or less prominent column of ossicles is seen down the center of the dorsal side of the arms. These
REVISION OF PALEOZOIC STELLEROIDEA. 47
are the radial columns of ossicles, which are especially well seen in Hudsonaster, Spaniaster, Devonaster, Xenaster, Calliasterella, and less prominently in Mesopalxaster, Promopalxaster, and Petraster. The prominence of the radials is lost in the same way as has been described for similar reduction in the supramarginals and inframar- ginals.
In primitive genera the supramarginals and radials lie closely adjacent as prominent columns, but in the great majority of Paleo- zoic Asteroidea these columns are more or less extensively separated from one another by the introduction of radial accessory plates. The latter are always small pieces and in general one can say that their number increases with geologic time and with the evolutionary complexity of the various stocks. At first the accessory pieces appear singly between the plates in the proximal region of the rays, where, increasing in numbers, they separate the primary columns more and more and finally also crowd in between the individual ossicles, es- pecially the proximal radials, pushing these apart more or less com- pletely. This is true not only in chronogenesis but also in onto- genesis. It is best seen in a study of the dorsal areas beginning with Hudsonaster and Spamaster, and proceeding to Mesopaleaster, Devonaster, Promopaleaster, and Urasterella. In the forms with great disks the development of accessory plates is extreme, as may be seen in Petraster speciosus.
The columns of radial plates are less persistent in development than any other of the primary columns. Like all of the primary plates, the radials are apt to lose their ponderosity and in the course of geologic time become smaller. In this way they may lose their individuality in the mass of dorsal plates, but in some cases radialia appear to fail to develop throughout the greater part of the rays, although one or more primordial ossicles of each radius are present on the disk. In certain species of Mesopalxaster, and more especially in Promopalzaster, the radialia are either not present or have been squeezed out of the mid line of each radius so as to be unrecognizable. In other forms of the latter genus they are well developed and arranged in linear columns. Promopal«aster as a rule has no radialia on the rays and the space between the supramarginals is occupied by many small accessory radial pieces. Among the Cryptozonia, radialia are usually not discernible as such on the rays, though present on the disk.
Accessory plates.—These small pieces of irregular form are space fillers between all of the primary columns of plates, with the exception of the ambulacrals and adambulacrals. As the body cavity grows - larger, skeletal increase takes place either through enlargement of the seven primordial columns of ossicles or by the intercalation and formation of new pieces, the accessory plates. The former method
50601°—Bull. 88—15——4
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is the one least often resorted to. The accessory pieces appear first chronogenetically on the disk, separating the primordial ossicles one from another in various ways, and as the body cavity grows larger in the course of geologic time, they wedge all of the primary columns apart proximally except the ambulacrals, which compensate for the widening of the rays by growing in size transversely. Some accessory plates also develop in the interbrachial areas separating the interbrachial marginals, as in Trimeraster and Xenaster, while in the large-disked forms, as Petraster, their number becomes excessive.
Ocular plates.—The large ocular plates seen in so many living Phanerozonia are very rarely developed in Paleozoic forms. In fact, the writer knows of but a single occurrence, in the Lower Car- boniferous genus Neopalzaster.
It seems to the author that these ossicles should have considerable significance in phylogeny because their large growth indicates that they are much older plates than any of the small adjacent pieces. In other words, in all genera where the ocular or sensory tentacle does not lie in an enlarged and grooved plate, the newly developed ossicles of either the ventral or dorsal side appear distally to the pre- viously borne pieces, i. e., at the tips of the rays, whereas in the stocks having ocular plates the new skeletal arrivals appear not at the tips of the rays but on the proximal side or inside of the eye ossicles Therefore, where ocular plates are present, these pieces are not only enlarged in size with age, but progressively pushed farther and farther outward as well by the growing ray tips that lie on their inner sides. This mode of growth may have originated once or several times, there being in the latter case parallel developments of ocular plates. This is a study that can not be pursued far among Paleozoic genera, but in the later forms may be productive in the discerning of phylogenetic lines.
After the above was written the writer read in Verrill (1914: 20-22) that Fewkes has shown the ocular plates to be the first to appear in the young, and that with growth they are pushed distally because of ‘‘the budding in of new plates between the apical plate and the one next toit.” These observations on living starfishes are therefore in harmony with the study of Neopalzaster, and go to show that the bulk of Paleozoic starfishes insert the plates of the primary columns in a different way, i.e., always distally. On this ground alone most of the Paleozoic starfishes should be grouped by themselves and apart from most of the subsequent Phanerozonia.
Centro-dorsal.—tIn the center of the disk of many Paleozoic genera of Asteroidea and of some Auluroidea is seen a more or less prominent plate, which is thought to be the equivalent of the centro-dorsal of the embryo of the living crinid Antedon (Comatula). It is a promi- nent though small plate in most of the forms of Hudsonaster and in
REVISION OF PALEOZOIC STELLEROIDEA. 49
Palzaster; it is also well developed though less conspicuous in Meso- palexaster, Spaniaster, Xenaster, Agalmaster, Devonaster, Neopalzaster, Palasterina, Monaster, Calliasterella, and Urasterella.
As the disk plates are rarely well preserved, and as the centro- dorsal has been seen in many Paleozoic species, the writer thinks it will be found in most of the forms of this era.
Primary disk plates.—In the most primitive and oldest Paleozoic asterids the centro-dorsal is surrounded by a variable but small number of diminutive accessory disk pieces. In mature Hudsonaster they form a single ring, but in the young of the cryptozonian Uras- terella (U. ulricht) and in mature Calliasterella there are none of these accessory pieces present. For these reasons it is thought that in the Ordovicic there will be found a small asterid, even more primitive than Hudsonaster, that will be devoid of accessory disk pieces.
Around the centro-dorsal of young Urasterella and in mature Calliasterella, there follows directly a ring of five larger plates. The same five plates are also seen outside of the single ring of accessory pieces in Hudsonaster and Spaniaster, and directly beyond the two rings of accessories in Aesopalxaster. These more or less large plates are radial in position and are the basal radialia above which continue the columns of successively formed radials.
Returning to Hudsonaster, we see that the first ring of prominent plates has 10 pieces, 5 of which are radial in position, the remainder interradial. The same is true for Spaniaster and Xenaster, while Calliasterella has an equal number of piates in the second ring. An analysis of these disks shows that 5 of the plates are either primary or secondary radialia, while the remainder are situated interradially, and upon them rest the 10 columns of supramarginals. The first prominent ring in Mesopalzaster shafferi and Devonaster and the second ring in Urasterella ulricht each have 15 plates, 5 of which are radialia, while the other 10 are supramarginals. Simplifying these statements and cutting out the accessory pieces, we learn that the disks of these genera—and others could be added—are composed of a centro—dorsal, a first ring of 5 radialia, and a second one with 5 radialia and 10 basal supramarginalia. This, then, is the same struc— ture postulated for the hypothetic phylembryo of Asteroidea and deduced through reduction of ossicles, as gleaned from a partial ontogenesis of Hudsonaster.
Axillary ossicles—In the most primitive asterid, Hudsonaster, one sees in each axilla a single large plate, on either side of which adjoin the 10 columns of inframarginals. The same arrangement obtains in Siluraster, Palzaster, and Australaster (here the genus occurs in the Permo-Carboniferous, and the axillaries are very large contrasting with the smaller ones of the Ordovicic Hudsonaster). In no other Paleozoic genera does this same development hold, though the single
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axillaries occur in many other forms where they are, however, pushed orally into the skeleton of the interbrachial areas. Single, not double, axillaries, therefore, make the simplest and smallest type of inter- brachial areas. Further complexity and enlargement of these areas are produced by crowding into them orally, first the axillaries and then one or more pairs of proximal inframarginals.
In Hudsonasier narrawayi one sees tiny single plates proximal to each axillary. These are clearly of no marked morphologic value and are to be interpreted as accessory plates. Similar single ossicles are also seen in genera with large interbrachial areas, asin Promopaleaster. They are regarded as space-fillers and without ancestral significance.
Interbrachial areas.—The simplest type of interbrachia! area is that just described. Increase in size and complexity of interbrachial struc- ture is a natural result from an eniarged body cavity. The first change in this direction is seen in Mesopaleaster, Spaniaster, Miomaster, and Devonaster, where the axillaries are crowded orally and surrounded distally by a pair of adjoining basal inframarginals, and proximally by a variable number of adambulacrals. The same development is seen but in somewhat modified form in the cryptozonian genera Urasterella (U. ulrichi and U. girvanensis) and Calliasierella. ere the axi!laries are present only in the young, but may be retained to maturity; in either case they may or may not be margined distally by basal infra- marginals. As the inframarginals in these forms are vanishing (pri- mitive Cryptozonia), we should expect to find related genera devoid of even the axillaries, and such is the case in Stenaster and Tetraster.
The next step in the enlargement of the interbrachial areas consists of the inward crowding of pairs of basal inframarginals, one or more at a-time. In Trimeraster these areas have the single axillaries and a pair of basal inframarginals, with the second pair of proximal infra- marginals making the margin of the axils. In Xenaster the first and second pairs of proximal inframarginals are enclosed, while in Pro- mopaleaster there are from one to three pairs in each interbrachial area. As these areas enlarge, it follows that more and more of the adambulacrals must also take part in the expansion. These ossicles are therefore called interbrachial adambulacrals. Further enlarge- ment, but not to any marked extent, takes place through the insertion of a variable number of accessory disk interbrachials. This is best seen in 7'’rimeraster and Xenaster.
Abnormal enlargement, but to a small extent, of the interbrachial areas takes place through oral crowding entirely of adambulacrals in pairs and through the increase in size of some of these ossicles. This type of development is known only in Anorthaster.
It has been shown how enlargement of the interbrachial areas comes about through oral crowding of the axilaries, proximal inframargi- nals and adambulacrals—pieces of the primary skeleton—but the
REVISION OF PALEOZOIC STELLEROIDEA. 51
greatest expansion is brought about by the introduction of more and more accessory disk pieces between the adambulacrals and inframar- ginals. The beginning of this development of the secondary skeleton is seen in Petraster and is variously progressive in the different species. They finally crowd more and more distally into the rays, as may be seen in Uranaster and Palxostella. Among the large-disked Crypto- zonia, as Schuchertia and the Palasteriscide, it is the ambital and abactinal accessory pieces that go to enlarge the arcs and body cavity.
CLASSIFICATION.
A good history of the various attempts at classifying the fossil starfishes is given by Spencer (1914:39-52). How recent starfishes are classified may be learned from Verrill (1914:24), and it will be seen that his principles are not always applicable to fossil forms be- cause of the loss of parts through fossilization. In subsequent pages the author will give his groupings up to superfamilies, but the time is not yet at hand for an ordinal classification applicable alike to fossil and recent starfishes.
Catalogue of Paleozoic Stelleroidea.—A catalogue of all Paleozoic starfishes was published by the writer in April, 1914, under the title “Fossilium Catalogus, Animalia, part 3, Stelleroidea paleozoica,” pp. 53 (Junk, Berlin). It gives the entire bibliography of the genera and species up to that date, and an outline of the classification adopted. The actual date of several new genera is of the work above cited, although they are also printed in the present book as new. This Bulletin is there cited as of 1914 and is now to be corrected to 1915. The above-mentioned catalogue will always be useful for ready refer- ence to the literature, although the larger volume repeats all of the essential references, corrected to November, 1914.
DESCRIPTION OF GENERA AND SPECIES.
Class STELLEROIDEA. Subclass ASTEROIDEA. PHANEROZONIA Sladen.
Asteroidea nearly always with large marginal plates. These consist in the Mesozoic and later asterids of completely superposed inframar- ginals and supramarginals; in the Paleozoic the rule is that the in- framarginals alone border the animal, while the supramarginals are always dorsal, generally alternate with the inframarginals, and are placed farther inward though resting more or less upon the latter.
Ambulacrals always present and opposite in arrangement in post- Paleozoic forms. In the oldest and most primitive Paleozoic forms they are apt to be alternate throughout the rays, or only so distally in the young parts. By far the greater number of Paleozoic forms, however, have the opposite arrangement.
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Oral armature always with the adambulacral pieces most con- spicuous.
This order is not known to appear before the Middle Ordovicic, and in the Paleozoic contains the following families:
Hudsonasteride. Xenasteride. Paleasteride. Neopaleasteride. Promopaleasteride. Palasterinide. Mesopaleeasterine. Lepidasteride. Promopaleasterine. Anorthasterine.
These seven families of Paleozoic asterids are all related to one another and seemingly had their origin more or less directly in Hudsonaster or a form very similar to it. Therefore the family Hudsonasteride is the primordial stock out of which all asterids progressively developed. Hudsonaster is massively and simply built, with the spines rudimentary and restricted to the adambula- crals and inframarginals; it is a small rigid asterid with few and comparatively large ossicles, nearly all of which are of the pri- mary skeleton. From it the evolutionary tendency was to get rid of the rigidity and ponderosity through the comparative reduction in size of the plates and the introduction of many smaller sec- ondary pieces, along with an abundance of spines. With this ten- dency once established, there arose several others: (1) elongation of rays, with greater flexibility and greater power of locomotion through the indefinite duplication of pairs of podia; (2) increase of body cavity in three different ways. This took place through the development of interbrachial areas (a) by the inward crowding of the single interbrachial axillaries, followed by more and more pairs of proximal inframarginals; (6) through the insertion of an indefinite number of accessory ossicles between the adambulacrals and the inframarginals, forcing the latter more and more outward; and (c) through the introduction of supernumerary rays. The latter development is probably abnormal, in that the tendency arose in the later larval life as is explained elsewhere. (See p. 207.) With these changes of the actinal side naturally must arise compensating growths of the abactinal surface and accordingly here is seen the introduction of accessory ossicles in various places.
Starting with Hudsonaster, there is one phyletic line developed through the elongation of rays, flexibility, and the increase in size of the oral region by the (a) method from the primitive Hudson- asteridz into the derived Palsasteride, Promopaleasteride, Xen- asteride, and Neopaleasteride. This is the most satisfactory line of evolution, resulting in the greatest variety of genera. Again with Hudsonaster as the radicle, another phyletic line is established through the increase of the body cavity by the (6) method, giving
REVISION OF PALEOZOIC STELLEROIDEA. 53
rise to the Palasterinide. This line of change is not at all so pro- ductive of genera as the former. Finally, a third phyletic line is established through larval adaptation, causing a sixth ray to develop and thereafter pairs of rays, resulting in the multi-rayed asterids of the family Lepidasteride. These phyletic lines may be expressed taxonomically as follows: Superfamily Promopaleasteracea, new. Includes families Hudsonasteridee, Paleeasteridee, Promopaleasteride, and Xenasteride. The Neopaleasteridz developed out of the Promopaleasteride. Superfamily Palasterinacea, new. Includes family Palasterinidee. Superfamily Lepidasteracea, new. Includes family Lepidasteride.
HUDSONASTERID, new family.
Most primitive known Phanerozonia.
Small, five-rayed, heavily plated asterids, with narrow ambulacral furrows and slightly alternate ambulacralia. The incipient inter- brachial ares are occupied by single axillary marginal plates. Abac- tinally the rays have five columns of ossicles, the radials in the center being bounded on either side by the supramarginals and inframarginals; the latter margin the rays and the ossicles of adjoining columns alter- nate with one another. There are no accessory ray plates of any kind. The disk has a prominent central disk piece separated by a small number of accessory disk plates from a ring of five large basal radials and five large basal interradial ossicles. Spines rudimentary and apparently restricted to the adambulacrals and inframarginals.
This family contains the genera Hudsonaster Stiirtz and Siluraster Jaekel.
Genus HUDSONASTER Sturtz.
Plates 1-6.
Palxaster (part) of authors.
Hudsonaster Stirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 224, 225.
Protopalxaster Hupson, Ottawa Naturalist, vol. 26, 1912, p. 25; vol. 27, 1913, pp. 77-84.—Raymonp, Ottawa Naturalist, vol. 26, 1912, p. 105 (genoholo- type, P. narraway’).—SrENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontgr. Soc. for 1913), 1914, p. 21.
The name is derived from the ‘‘Hudson River formation,” an Ordovicic series of strata of long endurance. If the stratigraphic term is used correctly, then these rocks have as yet furnished no starfishes of this genus; for this reason Hudsonaster is a misnomer and has no significance, but under the rules of nomenclature it must be accepted.
Generic characters.—Disk small and without actual interbrachial arcs. Rays five, short, tapering rapidly.
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Abactinal area of rays occupied by three columns of large, thick, more or less tumid or carinate, closely adjoining, tuberculate plates; more or less of the inframarginal plates are also to be seen, making five visible columns of plates on each ray abactinally. There is, therefore, a single radial column bounded on each side by two columns of supramarginal and two of inframarginal plates. The latter columns are the marginal plates both actinally and abactinally, but on the dorsal side are overlapped by the supramarginals. In the center of the disk there is a small but very tumid plate (central disk plate) around which is a nearly complete circle of smaller acces- sory plates and an open space which may represent an anal opening. Outside of this first circle of accessory plates there is a ring of 10 very large plates that in the geologically later species are stellate on the surface, 5 of which are radial and 5 interradial in position. The radial plates are the basal radial plates of the 5 medial columns, while the 5 interradial plates give rise to the 10 larger and conspicu- - ous supramarginal ossicles. The basal supramarginals adjoin one another in the axillary areas, and in the geologically later forms these also have stellate surfaces. Between each of the 5 inter- radial plates there is inserted a single plate, making a second but disconnected ring of accessory plates.
Madreporite abactinal, more or less large, adjoining one of the large interradial plates and between the basal plates of two supra- marginal columns of ossicles of adjoining rays.
No accessory ambital or abactinal plates.
Spines appear to be absent everywhere except on the inframarginal and adambulacral ossicles. Otherwise the surface is granular or tuberculate.
Inframarginal plates well-developed, tuberculate, and common to both the actinal and abactinal areas. These proximally adjoin the | five isolated and large axillary marginals, each one of which occupies an axil of the rays. Each plate, except the axillary ones, bears on its outer edges one to three apparently smooth, small spines.
Axillary plates quite conspicuous, marginal, and one in each actinal axil. In at least one of the species there is a single tiny acces- sory piece orad to éach axillary (H. narrawayi), and it is only seen on the inside of the skeleton.
Adambulacral plates numerous, one or two to each inframarginal plate and two on each side of each axillary marginal plate. All of these pieces bear at least two spines, one on the inner and another on the outer edges.
Oral armature consisting of at least five pairs of pointed and elon- gate basal adambulacral plates; each bears spines like the other ambulacrals. In rare eases issuing from beneath these ossicles may be seen five single stout spines or plates (tori) that are connected
REVISION OF PALEOZOIC STELLEROIDEA. 5d
with the pairs of ambulacral armature pieces. In H. narrawayi above or dorsal to the pair of large oral pieces there is another but smaller and modified pair of ambulacral ossicles clearly also a part of the oral armature:
Ambulacral grooves originally narrow and regularly tapering. Am- bulacral plates rectangular, practically opposite or very slightly alternating, one to each adambulacral plate. The ambulacralia of each column may be so closely adjoining as to leave almost no space for the podial openings, or there may be laterally between adjoining ossicles very large openings.
Genoholotype-—The genotype selected by Sttirtz is Palasterina rugosa Billings. The above generic definition is, however, largely based upon Palzaster incomptus Meek and P. matutinus Hall.
Distribution.—Restricted to the middle and upper portion of the Ordovicic. The following are the known species:
. matutinus (Hall). Trenton. . narrawayi (Hudson). Black River. . milleri, new species. Trenton. . incomptus (Meek). Maysvillian and Richmondian series. . rugosus (Billings). Lower Richmondian, Charleton forma- tion. H. batheri, new species. Upper Ordovicic, Girvan, Scotland.
Remarks.—Stirtz is unfortunate in selecting as the genotype of Hudsonaster, Palasterina rugosa Billings, a very poorly known starfish from the Richmondian of Anticosti Island. Therefore his original definition of Hudsonaster is not only very imperfect, but the specimen is wrongly interpreted. His characterization of the genus is as follows:
Of Palasterina rugosa only the abactinal side is known. On the disk occur orna- mented, deeply crenulate, star-shaped plates. Four [the specimen is distorted and has forced into view one of the inframarginal columns, while the one on the other side of the ray is shoved out of sight] regular and decided columns mark the rays, and of these the outer rows are stronger than the inner columns. The outer columns consist of unmistakable marginal plates [one is inframarginal, the other is a supramarginal column]. According to Billings there are even traces of the actinal marginals to be seen from the abactinal side. Spines absent [the usual spines of this genus are also present here]. The arms terminate sharply in points.
Stiirtz is correct in saying that this species can not be included in Palasterina and also that the genus has come to embrace a variety of unrelated genera. However, he does not say what are the actual generic characters of Hudsonaster, but as P. rugosa is not a Palasterina he concludes that as ‘‘new generic names are required I propose Hudsonaster for Palasterina rugosa Billings.’’ This species is undoubtedly congeneric with Palxaster incomptus, a form fully described in this work both from the actinal and abactinal sides, and is therefore taken as the genotype for the above generic defini- tion.
Sees
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The adopted genotype of Protopalexaster (P. narraway?) is described at length and in detail by Hudson, but, thinking the specimen showed the actinal side, he described the ambulacrals as epineural plates roofing over the ambulacral furrow, a character that he of course recognized as wholly anomalous for starfishes. Raymond later on showed that the actinal side of this specimen lies buried in the rock and that the entire abactinal plates are now gone, so that the view is of the actinal plates from their inner side, 1. e., an inter- nal view of the ventral skeleton (later Hudson combats this view). Under these circumstances nearly all of Hudson’s generalizations are fallacious and especially his statement that “we are dealing with an unrecognized and very archaic morphological type which links the Edrioasteroidea with the Stelleroidea”’ (1912: 24). A proper interpretation of the specimen shows it to be a primitive but other- wise a normal early Paleozoic starfish. Even though Hudson’s genus is far better determined generically than that of Sttrtz, it must give way to the older name Hudsonaster. No one regrets this more than the writer, because the generic name Protopalzaster ex- presses the phyletic relationship of these primitive starfishes and is a name that he has had in manuscript for the past 15 years.
Hudsonaster has its nearest known relationship in Palzaster, but differs at once from the latter in that the rays have abactinally five columns of plates, while Palzaster has but four. In other words, Palzaster has no radial columns of ray plates, but their place is oc- cupied by numerous small accessory pieces. The abactinal disk of Palzaster is also quite different in having numerous small acces- sory ossicles, while in Hudsonaster this area is devoid of these pieces and instead there are disk plates that are larger, far less numerous, and with a definite arrangement.
The plate arrangement of Hudsonaster is simple and primitive in that it distinctly retains to maturity much of the larval plate structure of recent species and does not develop accessory ambital or accessory abactinal plates as do its descendants Mesopaleaster and particularly Promopalzaster. In Hudsonaster the axils are occupied by single, large, axillary marginals, against which rest the columns of inframarginal plates of adjoining rays. In the other two mentioned genera, interbrachial arcs begin to develop by crowd- ing orally the axillary marginals, when, as in Mesopaleaster, the proximal plates of the inframarginal series of adjoming rays abut against each other. In Promopaleaster this crowding of the infra- marginal plates into the interbrachial areas is continued, always a pair of plates at a time passing orally. For other remarks on the development and distinction between these genera, see Mesopale- aster and Promopaleaster.
REVISION OF PALEOZOIC STELLEROIDEA. 51
In the Lower Carboniferous genus Neopalxaster the primitive disk structure of Hudsonaster is also retained in its essential fea- tures. Otherwise these genera are easily distinguished, as is pointed out in the remarks on Neopalzaster.
HUDSONASTER MATUTINUS (Hall). Plate 2, fig. 2; plate 3, fig. 2; plate 5, figs. 1, 2.
Asterias matutina Haut, Nat. Hist. N. Y., Pal., vol. 1, 1847, p. 91, pl. 29, figs. 5a, 5b.
Palxaster matutinus Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 283, pl. 9, fig. 2; rev. ed., 18681870, p. 325, pl. 9, fig. 2.
Petraster rigidus (part) Bruuines, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, pl. 10, fig. 3b (not fig. 3a)—Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist.,1868, p. 294; rev. ed., 18681870, p. 337.
Original description — Body small, with five radiating arms, arms elongated (length twice and a half the width of the body), terete, acute, composed of three rows of plates [abactinally], which jom above by their lateral margins. Beneath each upper lateral row of plates there is an inferior lateral range [inframarginal] vis- ible, leaving the sulcus beneath the middle row, which is often depressed. The dorsal plates are somewhat hexagonal; those of the arms quadrangular; surface punctate or granulate, perhaps from the removal of the spines covering the surface.
“The specimen is considerably crushed, and two of the arms broken off at the base; the madreporiform tubercle upon the back is not visible in our specimen. From its condition, the structure can not be entirely made out, but it is sufficiently clear to enable any one to recognize the species.’’
Emended description.—Specimen of the usual size (No. 3, Mus. Comp. Zo6l.) measures: R=14 mm., r=3.5 mm., R=4r. The larg- est specimen (Ottawa, Billings collection): R=16 mm., r=5 mm., R=3.1r. The smallest New York specimen (No. 26, Mus. Comp. Zo6l.): R=7 mm., r=2.5 mm., R=2.8r. Width of rays at base from 2.5 mm. to 5.5 mm.
Rays short, tapering rapidly, convex abactinally and flat actinally. Disk comparatively large, probably convex abactinally during life.
Abactinal area of rays consisting of 5 ranges of large, thick, and tumid granular plates. The 3 medial ranges, when not distorted by pressure, conspicuous, with the 11 to 12 plates of each column closely adjoining and considerably elevated above the inframarginal ranges. The proximal plates of each supra- marginal range lie against the large interradial plates and are more or less superposed on the large axillary marginals. In the center of the disk there is a distinct highly convex plate, around which is arranged a nearly complete ring of seven smaller pieces
58 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
and a vacant space which may be an anal opening. Five other small quadrangular plates are intercalated, one proximally to each of the large radial basal plates. Outside of these 12 mtercalary plates there is a ring of 10 quite large and conspicuous plates, 5 of which are radial and 5 interradial in position. The radial plates are largest and are the basal pieces of 5 medial or radial columns, while against the 5 interradial plates rest the 10 inframarginal columns.
Madreporite abactinal, quite small, situated immediately above a large interradial plate and between two basal supramarginal plates. Its position in relation to the anal opening is apparently as in P. incomptus.
Inframarginal plates in mature examples about 14 to a col- umn, and when not displaced completely, inclosing the adambu- lacral plates and margining the rays. ‘The axils are occupied by a very large, oval, axillary marginal plate. Hach inframarginal bears upon its outer surface one to three short, slender, pomted spines, which are finely striated longitudinally.
Adambulacral plates small, subquadangular in outline and about 19 in a column in specimens having 13 inframarginals. Hach plate bears on both the outer and inner edges a single spine and is like those of the inframarginal ranges.
The oral armature consists of 5 pairs of elongate adambulacrals, each pair being situated directly orad of the large axillary marginal.
Ambulacral plates }--shaped, practically opposite or but very slightly alternating, one to each adambulacral plate. In the ex- panded medial portion the ambulacralia are slightly superposed one above the other proximally, while the lateral portion of each plate is very slender, leaving between adjoining pieces comparatively large podial openings. ‘
Locality and formation—From the Trenton limestone, as follows: The type-specimen was found in the “shelly layers” at Trenton Falls, New York (Amer. Mus. Nat. Hist., No. 199), and another specimen was secured there by Mr. Rust (New York State collection). Dr. Walcott collected a slab with three individuals in the Lower Trenton at Rathbone Brook, near Newport, Herkimer County, New York; and Mr. Taylor got two specimens at Deerfield, Oneida County, in the same State (Mus. Comp. Zodl., Nos. 26 and 3). Mr. W. R. Billings found a specimen in the Trenton at Lachine, Quebec, and another from Government House Bay, Ottawa.
Remarks.—H. matutinus is intermediate in structure between the older H. narrawayi and the younger H. incomptus. It is larger than the former, has more plates in each of the columns, while the ambu- lacrals are deeply cut out for the podia, which is not the case in H. narrawayi. As H. matutinus is most closely related to H. incomptus more detailed comparisons must be made between them. Actinally
REVISION OF PALEOZOIC STELLEROIDEA. 59
the former differs in the wider ambulacral grooves. The difference of greatest value, however, is found on the abactinal area of the disk. In both species there is a central disk plate surrounded by a ring of accessory plates. In H. matutinus there are eight plates in this ring and in H. incomptus there are seven. Between all the basal radials in the latter species there is an accessory plate, or these are five in number, while in the former there are only two such plates. Again, the proximal plates of the supramarginal columns in JH. incomptus are larger than any others of the abactinal area, while in H. matutinus they are smaller than the basal radials and their form and ornamentation are quite different. The madreporites are also quite different. In general, H. wncomptus is larger, stouter, the rays broader and the disk has a greater number of accessory pieces. These features are still more pronounced in H. rugosus (Billings). Viewing these differences developmentally, the distinctions are slight, which proves the three forms to be genetically related, but specifically the differences are sufficiently marked to be regarded both morpholog- ically and geologically as of specific value. Apotype.—Cat. No. 60603, U.S.N.M.
HUDSONASTER NARRAWAYI (Hudson). Plate 1, fig. 1; plate 2, fig. 1; plate 4, fig. 1.
Protopalxaster narrawayi Hupson, Ottawa Naturalist, vol. 26, 1912, p. 25, pls. 1-3; vol. 27, 19138, pp. 77-84, pls. 8, 9 —Raymonp, Ottawa Naturalist, vol. 26, 1912, pp. 105-107 —Hupson, Bull. N. Y. State Mus., No. 164, 1913, pl. 5.— Spencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, p. 21, fig. 19.
Description.—Specimens small, an average individual from St. Paul, Minnesota, measuring: R=5 mm., r=3 mm., R=1.6r.. Width of ray at base 2.7 mm. The three good specimens show only the actinal side while the fourth free siliceous one is too poorly preserved to make out more than the form.
Inframarginal columns have from 6 to 9 plates, while the adambu- lacrals and ambulacrals each have from 11 to 12. Ambulacral plates large and solid, rectangular, with slightly rounded ends. As these plates are not t--shaped as in other species of this genus it may be shown that this character is of generic value, in which case Proto- palxaster will have to be revived.
Inside of each of the large axillary plates lies a pair of oral armature pieces that are in form very much like the adjoining adambulacrals. From beneath these ossicles projects a stout and long, rounded, arma- ture rod, the torus (a tooth or chisel), the 5 teeth meeting together in the center of the mouth. These armature rods and more especially the 10 pairs of ambulacral armature pieces are seldom scen in fossil starfishes, and none shows it more clearly than the Yale specimen
60 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
of H. narrawayi. In the holotype of this species, here illustrated, are seen additional pairs of oral armature ossicles. These are situated directly above or dorsal to the pairs of large armature plates, and are probably overlapping ambulacralia modified into the actinostomial ring.
Locality and formation.—In the Black River formation, as follows: The holotype was found by Mr. J. E. Narraway at City View, near the Central Experimental Farm at Ottawa, Canada; it is now in his private collection. An excellent specimen was found by Mr. Townshend near Kirkfield, Ontario, and is now in the Peabody Museum of Yale University. Many years ago Dr. Ulrich found a fine specimen at St. Paul, Minnesota, and another good one in the Lower (Glade) Lebanon limestone of the Stones River series at Shelbyville, Tennessee. These two specimens are in the United States National Museum (Nos. 60602, 60619). Mr. Moritz Fischer secured a coarsely silicified individual of this genus at Curdsville, Kentucky, and this is now in the Beecher collection in the Yale Museum; it may, however, prove to be of another species, distin- guished by its stouter appearance, wider disk, and smaller axillary plates.
Remarks.—Originally the writer included specimens of this form under P. matutinus, regarding them as but young individuals of Hall’s species. However, as the specimens are all geologically older, are always smaller and stouter, and with fewer plates in all of the columns, Hudson’s species is retained as valid. It is the ancestral form and the most primitive species of Hudsonaster and hence the most primitive Paleozoic starfish. It is primitive because of its extreme simplicity of structure, in that the columns and plates are reduced to the smallest number and all of them are closely adjoining and without intercalary plates of any kind. Then the spines are developed only on the actinal side and as protection for the podia. For further information see generic remarks under Hudsonaster.
Cat. Nos. 60602, 60619, U. S. N. M.
HUDSONASTER MILLERI, new species. Plate 4, fig. 2.
Description.—Of this form there is at hand but a single poorly preserved individual showing the actinal side. It is a more slender species than H. matutinus, has a larger and more rectangular axillary plate, and the proximal inframarginals have each about 13 to 15 plates and the adambulacrals from 18 to 20. No ambulacrals are preserved. The specimen measures: R=about 12 mm., r=3 mm. Width of ray at base 4 mm., at mid-length 3 mm.
Locality and formation —Found by Prof. Arthur M. Miller, after whom the species is named, in the Lower Lexington (Wilmore)
REVISION OF PALEOZOIC STELLEROIDEA. 61
limestone of the Trenton, in Fayette County, Kentucky. The holotype is in the collection of the State University of Kentucky at Lexington.
HUDSONASTER INCOMPTUS (Meek).
Plate 6, figs. 1, 2.
““Goniaster” of AGAssiz, GRAHAM, ANTHONY, and James, Amer. Journ. Sci., ser. 2, vol. 1, 1846, p. 441 (nomen nudum).
Palzaster incomptus MerK, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 275; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 64, pl. 4, figs. 5a, 5b.
Palzaster simplex MittER and Dyer, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 29, pl. 1, fig.6.—Mrtuer, N. Amer. Geol. Pal., 1889, p. 266, fig. 380.
Palxaster clarket Miter, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 102, pl. 3, fig. 5.
Palzaster clarkana MittER, Journ. Cincinnati Soc. Nat. Hist., vol. 3, 1880, p. 236.
Original description (P. incomptus).—‘‘Small; rays rather short, or only about once and a half as long as their breadth at their inner ends, and rapidly tapering to their outer extremities, which are somewhat obtusely angular. Disk equaling in breadth the length of the rays. Dorsal side of the rays composed each of three rows of pieces that are wider than long, about nine in each row, and increase rather rapidly in size inward to the margin of the disk, which is composed of smaller pieces; afew very minute pieces apparently sometimes occur between the rows on the dorsal side of the rays [none are apparent in our material]. Surface of the dorsal pieces a little granular, but apparently without spines. Madreporiform piece rather small, a little oval, or almost circular [or trapezoidal], nearly flat, and marked by fine, irregularly interrupted, radiating strie. Ventral side unknown.”
Emended description.—R =11 mm.,r=6 mm., R=1.8r. Width of ray at base 6 mm. Another larger specimen measures: R=16 mm., r=7mm., R=2.3r. Width of ray at base 8 mm. Smallest speci- men: R=4.5 mm., r=2 mm.
Rays short, stout, tapering rapidly, convex abactinally and longi- tudinally ridged, flat actinally. Disk large, probably very convex abactinally during life.
Abactinal area of rays consisting of five columns of large, thick, tumid, alternating, granulose plates. In the center of the disk there is a distinct, highly convex plate around which is arranged a nearly complete ring of seven smaller pieces and a comparatively large open space which possibly represents an anal opening. This ring is fol- lowed by another composed of five large interradial plates between each of which laterally and somewhat centrally is intercalated a smaller plate radial in position. Laterally and distally to each of the five large interradial plates are five large radial plates which are the basal pieces of the five radial columns. Against the basal plates of the medial ranges there adjoin laterally two large stellate ossicles,
62 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
each of which is the proximal plate of a supramarginal column. The rays are margined by the inframarginal plates. There are 10 plates in each radial and 9 in each supramarginal column.
Madreporite abactinal, situated interradially and distally against the large interradial plate of the second ring, which is in front of the anal opening, and between two of the proximal supramarginal plates. It is trapezoidal in form, flat, and marked by very fine, dichotomous, radial striz.
Inframarginal plates completely inclosing all other plates and com- mon to both the abactinal and actinal surfaces. Usually there are 9 or 10 in a column, not counting the axillary plates. Spines are present at least along the inner edges of the inframarginals.
Abactinally the axillary marginals are not prominent but actinally they are very conspicuous. No spines appear to be connected with these ossicles.
Adambulacral plates small, subquadrate, usually 2 to each inframarginal or from 18 to 22 plates in each column. From 4 to 6 are situated around the inner edge of each axillary, of which the 2 central ones are largest, being one of the 5 pairs of plates making the oral armature. The adambulacral plates originally bore on their lateral and inner edges numerous, very short, thick spines.
Ambulacral plates nearly entirely concealed by the adambulacral plates, apparently as numerous as the latter, and, so far as can be determined, like those in P. matutinus Hall.
Locality and formation:—In the lower, middle, and upper beds of the Cincinnatic (Ordovicic). Ten specimens have been studied: Four in the Harris collection in the United States National Museum (No. 40882) from the Richmond formation (Waynesville division) about Waynesville, Ohio; another from the same place and formation in the University of Chicago Museum (Gurley collection, No. 10977); one from the hill quarries in the Maysvillian series (Vaupel collection, U. S. Nat. Mus., No. 60616) back of Cincinnati; another, said to be from Cincinnati, in the University of Toronto (Walker collection, No. 691 H. R.); the type-specimen, now in the Museum of Com- parative Zodlogy, also from Cincinnati; one in the Ulrich collection of the United States National Museum (No. 60617), found back of Covington, Kentucky, in the Maysville formation, about 315 feet above low-water mark in the Ohio River; and the type of Palezaster simplex Miller, found near Raysville, Ohio (Faber collection, Uni- versity of Chicago Museum, No. 8830). The holotype of P. clarkana Miller is in Professor Harper’s collection at Cincinnati, while another specimen is in the Ulrich collection of the National Museum (No. 60618).
Remarks.—The writer has seen the type-specimen of Palzaster simplez Miller, which agrees with the description and figure given
REVISION OF PALEOZOIC STELLEROIDEA. 63
by its author, and it is like other specimens in the Harris collection known to be H. ineomptus (Meek). Of the latter, Meek only described the abactinal area, while Miller’s specimen shows the actinal side. The four specimens in the Harris collection unmistakably affirm that both forms are identical, and since Meek’s name has priority it is here accepted.
For remarks as to the relationship of this species see H. matutinus.
Through the kindness of Prof. George W. Harper, principal of the Woodward High School, Cincinnati, Ohio, the writer was enabled to study ‘the type of Palzxaster clarkana Miller. The specimen is a little abraded, but shows all the characters of H. incomptus except that it is much smaller in size. The abactinal area on a cursory examina- tion shows but three columns, but in several places can be seen pro- jecting small parts of the inframarginal columns. The disk also shows the same general arrangement and number of plates as in H.incomptus. There is therefore nothing except the smaller number of plates in the columns to distinguish P. clarkana from H. incomptus. Bearing in mind that the former is but one-third the size of the latter, it is not remarkable that P. clarkana should have but 6 or 7 plates while H. incomptus has 9 to 10 plates in the same columns. The entire difference is accounted for when one regards P. clarkana as the young of H. incomptus.
Another small but very poorly preserved specimen showing the actinal area is in the Ulrich collection of the National Museum and agrees with the type of P. clarkana. Its measurements are: h—4.5 mm. *=2 mm., R=2.26.
The only ontogenetic character observable in these small speci- mens of H. incomptus is that the columns have fewer ossicles, and the same is true of the abactinal area of the disk. It has a central disk plate, the first rmg of small plates and the second ring of basal radial and interradial plates. But no intercalated small plates radial in position are present. The second ring of 10 plates and the central plate are the most prominent. If one were theoretically to reduce the size of the animal still more, the plates of the first rmg would be the first to go and the rays would be simultaneously very much shortened, probably obsolete, resulting in a hemispheric nonstellate starfish. The abactinal area seemingly will then have but a central disk plate and 10 others, 5 radial and 5 interradial in position. On the actinal side there will be but the 5 axillary marginal plates separated from one another by the ambulacral furrow and the ambulacralia. This hypothetic animal therefore closely resembles avery young Comatula without the stalk or column, and also the stage of living asterids following the brachiolarial.
Cat. Nos. 40882, 60616, 60617, 60618 U.S.N.M.
50601°—Bull, 88—15——5
64 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. HUDSONASTER RUGOSUS (Billings). Plate 3, fig. 1.
Palasterina rugosa Bruines, Geol. Surv. Canada, Rep. of Progress for 1853-1856, 1857, p. 291; Geol. Surv. Canada, Can. Org. Remains, dec. 3, 1858, p. 77, pl. 9, figs. 2a-c.
Palasterina rugosa Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palzontogr. Soc. for 1861), 1862, p. 27.
Hudsonaster rugosa Stirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 218, 224, 225.
Original description.— Two inches [not over 47 mm.] in diameter, rays five, acute at their apices and rapidly enlarging to a breadth of four lines [about 11 mm.] at the disk, which is eight lines [about 17 mm.] in width. The specimen shows the upper [or abactinal] side of the fossil only; some of the plates are absent from the center of the disk, but those which remaim are very prominent in their centers, and roughly ornamented by four or five deep crenulations or furrows from near the center to the edges, producing a star-like appearance resembling a half-worn plate of Glyptocrinus decadac- tylus; their diameter is from one to two lines [largest diameter 4 mm.].
“The rays are composed (at least the backs and sides of them) of four rows of plates [due to distortion, a careful analysis shows five columns] which are so very prominent that they appear to be almost globular, and even pointed in their centers, the central [radial] rows are the smallest [as in H. incomptus]; the first four plates of the outer [supramarginal] row occupy three lines in length, and of the inner [radial] rows nearly as many. Toward the point of the arm all diminish rapidly in size.
‘Beneath the outer [or supramarginal] rows two others can be seen [the inframarginal], which are probably the outer marginal plates of the under [or actinal side], corresponding to those of Petraster rigidus.””
Locality and formation.—Richmondian series, Charleton formation, at Charleton Point, Anticosti Island. Two specimens collected by J. Richardson are now in the Victoria Memorial Museum at Ottawa, Canada (No. 1999).
Remarks.—The same description was republished in 1858 with the addition of three figures. These, and a direct examination of the two type-specimens, show that this species clearly belongs to Hudsonaster and that it is closely related to H. incomptus. The smaller free specimen preserves a portion of the disk and parts of two rays and shows clearly the presence of a single large axillary plate. H. rugosus, however, attained a considerably larger growth, has a greater number of plates in each column and these are described as ‘‘almost globular,” while in H. incomptus the abactinal plates are very convex but not globular. Then the basal supramarginal and
REVISION OF PALEOZOIC STELLEROIDEA. 65
radial plates are much more decidedly ornate. Each of the supra- and inframarginal columns has 14 plates against 9 in H. incomptus, and of adambulacrals there are not less than 24 in a column against 18 to 22in thesame form. All of the ossicles are as strongly papillose but not more so than in H. incomptus. The detail of the disk is not determinable.
HUDSONASTER BATHERI, new species.
Plate 3, fig. 3.
Tetraster wyville-thomsonti NicHotson and Erxeripae (part), Mon. Silurian Foss. Girvan Dist., Ayrshire, fasc. 3, 1880, p. 324, pl. 21, figs. 1, 2 (not the other figs.).
A small Hudsonaster. R=6 mm., r=2.7 mm. The largest specimen: R=8 mm.
Actinal side only known. Inframarginal columns the largest, with 8 or 9 distinctly tuberculate plates. Inside of these are the columns of narrower and slightly shorter adambulacrals that lie somewhat below the level of the inframarginals; there are 10 or 11 of these plates bounding the ambulacral grooves, and the pieces of adjacent columns are opposite or nearly opposite one another. The ambulacral grooves are very narrow and deep and no ambulacralia are discernible.
Formation and locality.—Dr. F. A. Bather made wax squeezes for the writer from three natural molds in the collection of Mrs. Robert Gray, Edinburgh; the originals are from the Upper Ordovicie of Thraive, Girvan District, Scotland. The holotype is the specimen illustrated as above cited.
Remarks.—Nicholson and Etheridge confused at least one of these specimens with their Tetraster wyville-thomsoni, a species of totally different construction, a cryptozonian, described elsewhere in this work. Actinally the new species is in harmony with Hudsonaster and although the abactinal side is unknown, it is thought that it will be found to be like that in H. matutinus.
Cat. No. 60601, U.S.N.M.
Genus SILURASTER Jaekel.
Text fig. 6.
Siluraster JAEKEL, Zeits. geol. Ges., vol. 55, 1903, Protokol, p. 13 (106), figs. 2, 3, on p. 108.—SprencER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontgr. Soc. for 1913), 1914, p. 18.
Description.—‘A typical asterid with opposite ambulacralia and with well-developed marginalia, therefore a true form of Phanero- zonia. The strongly folded madreporite lies dorsally in an inter- radius.”’
66 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
From the two excellent illustrations the following is made out: Inframarginals conspicuous and as large as the adambulacrals. Both columns finely tuberculate, with the ossicles of each alternating with one another. Proximally the inframarginals of adjacent rays rest on a somewhat larger axillary plate. The interbrachial areas are therefore made up of single axillary ossicles (Jaekel’s marginal oral) and in front of these lies a pair of pointed adambulacrals, the conspicuous pieces of the oral armature. These are perforated for the continuation of the ring canal. The podial openings as usual lie in the corners. of four adjacent adambulacrals and ambulacrals, but there is a de- cided tendency to restrict them to only one of the am- bulacral corners.
Abactinal area unknown.
Remarks. —This genus appears to be closely related to
Hudsonaster, but Fic. 6.—SILURASTER PERFECTUS (JAEKEL’S FIGURE 3). @) TO ds, AMBU- : : : LACRALIA OF ONE SIDE; ABOVE THESE ad) TO @d9, THE ADAMBULACRALIA, until Sa luraster 18 ad, AS MOUTH CORNER PIECE; @/g, PODIAL GROOVES; @pg, PODIAL OPEN- IMOTe fully worked INGS; ™, INFRAMARGINALIA; 70, THE SINGLE AXILLARY INFRAMARGINAL; : : : Rc, RING-CANAL IN MOUTH CORNER PLATES. out it will remain as an obscure genus.
Genoholotype and only species.—S. perfectus Jaekel. Ordovicic (D4), Zahorzan, Bohemia.
Family PALAASTERID Gregory (emend.).
Palzasteride (part) Mititer, N. Amer. Geol. Pal., 1889, p. 216.—Grergory, Geol Mag., dec. 4, vol. 6, 1899, p. 344 (contains Paleasterine, Xenasterine, and Lindstromasterine); Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.
Palzasterine Scuonvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 244.
Palxgoniasteride (part) Stiirtz, Paleeontographica, vol. 36, 1890, p. 246 (contains Aspidosomella and Palzaster).
Primitive, derived, five-rayed Phanerozonia with. the ambulacrals slightly alternate or opposite. Interbrachial ares incipient or some- what enlarged, and occupied by single axillary marginal plates. No accessory interbrachial or axillary interbrachial plates present, but there are developed accessory abactinal ray ossicles. Actinal plates consisting of ambulacrals, adambulacrals, and inframarginals. Mad- reporite abactinal.
Contains:
Paleaster Hall. Ausiralaster, new genus.
REVISION OF PALEOZOIC STELLEROIDBA. 67
Genus PALAZASTER Hall (emend.). Plate 7, figs. 1-4. :
Palxaster Hatt, Nat. Hist. N. Y., Pal., vol. 2, 1852, p. 247; Tweutieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 282; rev. ed., 1868=1870, p. 324.—ZrrreE., Handb. Pal., vol. 1, 1879, p. 452.
Palzxaster NicHotson and ErHEeripGe (part), Mon. Silurian Foss. Girvan Dist., Ayrshire, fasc. 3, 1880, p. 319.
(Not Palzxaster SattER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 323= Uras- terella.)
(Not Palzaster of most AUTHORS. )
Generic characters.—Disk small and without distinct interbrachial arcs. Rays five and slender. |
Abactinal area of disk centrally occupied by a large plate, then a ring of 5 separated, somewhat smaller, radially situated ossicles, and inside the axillary pieces there are 5 subtriangular interradial plates, against which lie 10 very large and conspicuous proximal supramarginal plates. Between the central, radial, and interradial plates are numerous small accessory pieces which separate the pri- mary ossicles one from another. These accessory plates also continue to crowd from the disk into the rays between the supramarginals, and thus take the place of the radial columns, but are absent in the distal third of the rays. Each ray has therefore 4 conspicuous columns of plates, the 2 supramarginals situated inwardly of the 2 marginal inframarginals. The former columns terminate in 10 very large proximal plates situated in the axils of the disk, while the inframarginals rest against the 5 very large actinal axillary margi- nal pieces. All of the large plates are centrally smooth, bordered by a pustulose area.
Madreporite abactinal, of medium size, circular in outline, and radially striate. It lies on top of two proximal supramarginal plates and the adjoining interradial plate.
Inframarginal plates thick and large, about as many in a column (13) as in those of the supramarginals (13 or 14). The latter do not completely overlie the inframarginals, since these bound the rays both actinally and abactinally. The inframarginal plates, like the plates of the abactinal area, have each a large, smooth, central space encircled by a pustulose area. From their inner sides articu- late short, thick, blunt spines, of which there are apparently not more than 2 to each inframarginal plate.
Axillary marginal plates large, hexagonal, one in each axil and common to both sides of the disk axils.
Adambulacral plates small, tumid, alternating in the main with the inframarginal plates throughout the distal two-thirds of the rays, but toward the mouth there are a few more adambulacrals than in- framarginals. (In the type-specimen there are 13 of the latter in a column to 16 of the former.) Oral armature consists of at least 5 pairs of drawn out and pointed basal adambulacrals. Along the inner
68 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
side of each adambulacral plate there is a linear brush of from 5 to 7 short, slender spines.
Ambulacral grooves very narrow, tapering but very slowly. Am- bulacral plates obscured by the rock but apparently very short, one to each adambulacral and placed opposite one another.
Genoholotype (type by monotypy) and only species.—P. magarensis Hall. Siluric (Rochester shale).
Remarks.—To this genus has been erroneously referred a multitude of Paleozoic starfishes. It is to the starfishes what Terebratula and Rhynchonella used to be among the brachiopods—a general dumping ground for Paleozoic forms. This lack of generic conception regarding Palzaster lies somewhat in the fact that Hall’s original diagnosis is very meagre and that he did not describe nor illustrate the abactinal surface, probably the most important area amongst Paleozoic aster- ids for specific and generic differentiation. Of the twenty-four Amer- ican species listed under Paleaster by S. A. Miller’ only one now appears: to belong there, the genotype. All others are here referred to Hudsonaster, Urasterella, Mesopalzaster, Promopalzaster, Anorth- aster, Devonaster, and Neopalzaster.
No new material of this genus accessible to the writer appears to have been found since Colonel Jewett discovered the original two specimens of Palzaster niagarensis. The writer therefore had to make the most of this material, and to determine the structure of the abactinal area he worked away much of the blue shale from the back of the one good specimen. ‘The finer detailed structure was then revealed by cleaning with caustic potash.
In 1858 Billings proposed the genus Stenaster? and writes that ‘as it has been suggested that the two species hereinafter described should be referred to Palzaster, I give the following figure of the genus in order to show the difference.’ This figure is a good reproduction of Hall’s figure 27. Billings then points out that ‘‘if the large plates which border the grooves in Palzaster be adambulacral, then there are only five oral plates, whereas in Stenaster there are ten. But if they be not adambulacral but marginal plates, then Palxaster must have both marginal and adambulacral [the correct view], while Stenaster has only the latter.”
Hall’s generic description is very meager and his figures give the impression that the rays bear but a single column of marginal spiniferous plates. With this evidence one can understand why Billings was in doubt as to whether these plates are inframarginals or adambulacrals and therefore the uncertainty as to the nature of the five large axillary marginal plates. If, however, he had read Hall’s accurate specific description, Billings would have seen that an important discrepancy existed between the description and figures.
1 North American Geology and Palwontology, 1889, p. 265. 2 Geol. Surv. Canada, Canadian Organic Remains, dec. 3, 1858, pp. 77, 78.
REVISION OF PALEOZOIC STELLEROIDEA. 69
Hall writes: ‘‘Lower side of arms showing two ranges of plates on each side of the avenue, the outer range composed of strong hex- agonal plates, with an inner range of smaller ones alternating, the latter usually covered by tufts of spines.”” The type-specimen clearly shows columns of adambulacral and inframarginals bordering the ambulacral grooves and that in each axil there is a single large axillary marginal plate. This matter need not here be followed further than to add that Stenaster originally included two generic types, both of which are widely different from Palzaster. On the other hand, Hall! is In error in regarding all of Stenaster as synonymous with Uraster- ella McCoy, a name never properly defined and finally abandoned by its author. Billings originally referred to Stenaster, S. salteri, and S. pulchellus. 'The latter is certainly congeneric with the type of Urasterella as illustrated by Salter, but the former is quite different, as is pointed out elsewhere in the remarks on Stenaster, which is a good genus.
Palzaster in many respects reminds one of Hudsonaster, and the actinal generic characters may be regarded as alike in both. The abactinal area is also similar, but in Hudsonaster there are five columns with decidedly fewer plates, while in Palzxaster there are no radial columns. The former genus is the more primitive one and the progression in differentiation toward Palxaster appears to be as fol- lows: In Hudsonaster, the rays throughout are composed of five columns of plates, two inframarginals, two supramarginals, and one radial. In Palxaster, there are but four columns in the outer third of the rays, two infra- and two supramarginals, but in the proximal two-thirds where the radials are also absent, their place is occupied by numerous small, irregular accessory plates. This introduction of numerous supplementary plates also takes place to a far greater extent on the disk, where they are crowded in between the larger central and the five basal radial plates.
The primitive disk structure of Palxaster is in large part again repeated in Neopalzaster, but otherwise the two genera are different. PALEASTER NIAGARENSIS Hall.
Plate 7, figs. 14.
Palxaster niagarensis Haur, Nat. Hist. N. Y., Pal., vol. 2, 1852, p. 247, pl. 51, figs. 21-23 (not p. 352, pl. 85, figs. 8-10, possibly an undescribed species).—Bituines, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 78, fig. 1.—Ha., Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 282; rev. ed., 18681870, p. 324.—QueEnstTeEpT, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 73, pl. 92, figs. 32, 33—Hupson, Bull. N. Y. State Mus., No. 164, 1918, pls. 9, 10, 12, 13.
Original description.— Body stellate; disk small; arms short, terete with a deep avenue on the lower side, which is margined by strong short spines; centre of plates (in the fossil) nearly smooth, margins
1 Twentieth Rep. N. Y. State Cab. Nat. Hist., rev. ed., 1868=1870, p. 325.
70 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
strongly granulate; lower side of arms showing two ranges of plates on each side of the avenue, the outer range composed of strong hexagonal plates, with an inner range of smaller ones alternating, the latter usually covered by tufts of spines; a large pentagonal plate inserted at the base of the arms, on the lower side.
‘“‘Tn this species, the arms are about twice as long as the width of the disk. There are about 15 or 16 plates in each range from the base to the apex of the arms. The range of the plates margining the avenue are usually not visible, the whole being covered by the short spines, which also partially fill the avenue.”
In 1870 Hall added the following important observations:
“T have distinctly recognized the two ranges, marginal and adambulacral plates; but the inner ones are not shown in the figure as they should have been, while the large plate at the axil of the ray (though the adjacent small oral plates of the inner range are not seen) is evidently part of an incomplete series, and clearly belongs to the marginal range.
“The genus Palezaster has two ranges of plates on each side of the ambulacral groove; marginal and adambulacral plates on the lower side, besides ambulacral or poral plates. The upper or dorsal side has three or more ranges of plates.”’ :
Emended description.—Measurements: R=18 mm., r=5 mm. Width of ray at base 5 mm.
Rays long, slender, tapering slowly; abactinally strongly convex and longitudinally ridged; flat actinally. Disk comparatively large, strongly convex and probably abruptly elevated above the rays abactinally. There are no interbrachial ares, but the five axillary marginal plates occupy the axils and are also partially visible abactinally.
Abactinal area of rays consisting of 4 columns of large, thick, convex plates. These are the supra- and inframarginal columns. The supramarginal plates of each ray are distally in contact with one another along the mid-line, but proximally they are forced more and more apart by a series of small, irregular, accessory plates. In the center of the disk there is a small, convex disk plate around which are situated radially 5 other small ossicles, all of which are sepa- rated from each other apparently by a considerable number of minute intercalary pieces. Just inside of the axils are 5 large, subtriangular, interradial plates and adjoining these directly are 10 large and con- spicuous ones, the proximal plates of the supramarginal columns. In each column there are about 13 plates, not counting the proximal piece. Between all of the‘ larger plates of the disk and for two- thirds the length of the rays between the supramarginals, there are numerous small, convex, irregularly shaped, accessory plates. All
REVISION OF PALEOZOIC STELLEROIDEA. te
the larger ossicles of both sides are centrally smooth, surrounded by a finely pustulose border.
Madreporite situated interradially and distally upon the three large plates just inside an axillary marginal plate, two of which are the proximal plates of supramarginal columns of adjoining rays. It is circular in outline, flat, and radially striated.
Inframarginal plates occupying the outer edges of both the actinal and abactinal areas; from 13 to 15 plates in each column. The supramarginal plates are situated above and inside the inframarginals, which inwardly bear short, thick, club-shaped spines. Otherwise they are ornamented like the abactinal plates.
Adambulacral ossicles small, subquadrate, each one alternating distally with an inframarginal plate, but proximally they are some- what more numerous, there being from 17 to probably 20 in a column. On these plates le two series of spines—the two short, thick, club- shaped ones of each inframarginal plate—while on the inner side of each adambulacral there is inserted a linear brush of from five to seven slender, short spines that are outwardly and laterally directed.
Ambulacral grooves very narrow, deep, and gradually tapering. Ambulacral plates not well seen but apparently very short, one to each adambulacral and directly opposite one another.
Axillary marginal plates five in number, very large and conspicuous actinally, also showing slightly abactinally.
Locality and formation.—The only good specimen was found many years ago by Col. E. Jewett in the Siluric (Rochester shale) at Lock- port, New York. A fragment of the ray of a much larger individual, nearly twice the size of this type, was found by the same gentleman at the same place. These specimens are now in the paleontological museum of Cornell University (No. 7331) and were presented by Hon. Ezra Cornell. Long after the study of the form was com- pleted another specimen preserving two rays and showing the actinal side was learned of in the University of Toronto (Walker collection, No. 1008). It was found at Grimsby, Ontario.
Remarks.—This species has never been well described nor figured, and has accordingly led to endless generic confusion. Almost any Paleozoic starfish with large marginal plates has been referred to Palzaster. This lack of generic conception was partially due, as stated above, to the fact that the abactinal side remained unknown. The specimen hes imbedded in blue shale showing the actinal area, and the abactinal side was revealed by the writer by cutting away the slab to the starfish and then developing the individual plates with caustic potash.
In ageneral way Palzaster niagarensis resembles several species but all are distinguished by generic characters. The nearest one is Hudsonaster incomptus from the Cincinnatic strata, but it differs at
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once in having five instead of four columns of large abactinal plates. There are also a far less number of the accessory plates so numerous on the disk and the proximal medial areas of the rays in Palzaster niagarensis.
Hall’ refers a fragment to this species which clearly is of quite another species. It is very far removed from P. niagarensis and for the present need not be considered. The specimen has not been seen by the writer.
AUSTRALASTER, new genus. Plate 4, fig. 4.
Palexaster (Monaster) ETHERIDGE, jr. (part), Mem. Geol. Surv. New South Wales, Pal., No. 5, pt. 2, 1892, p. 74.
Monaster GREGorY, Geol. Mag., dec. 4, vol. 6, 1899, p. 345 (not of Etheridge, jr.).
Australaster ScHucHERT, Fossilium Catalogus, Animalia, pt.3, April, 1914, p. 12.
Austral=southern and aster. A Paleozoic starfish restricted to Australia.
Generic diagnosis —Animal attaining a very large size, with five long, slender, almost straight-sided rays, termimating bluntly. Interbrachial areas comparatively small, widely concave, and oecu- pied by ponderous, single, axillary marginals and inframarginal plates.
Abactinal area unknown (see A. (?) stutchburiz).
Actinally the animal is bounded by inframarginal plates which however do not appear to be present in the distal third of the rays. If such plates are present in these outer regions, they are either very small or gradually pass from the actinal to the abactinal area, the latter condition occurring in related genera. The inframarginals in the outer third of the rays are small, subquadrangular, and rounded, thence they increase rapidly in size proximally, become decidedly transverse, and in the axils the columns abut against a very large axillary inframarginal. The largest plate is the axillary marginal, orad to which occur the pairs of enlarged oral armature ossicles. The inframarginals appear to be nearly smooth and devoid of spines.
The adambulacrals in the distal third of the rays are numerous, very short, but quite wide—that is, are decidedly transverse, and decrease rather rapidly in breadth toward the tips of the rays. Proximally these plates also decrease quickly in width and rapidly pass inside of the inframarginals. Inside of the axillary marginals the plates are again prominent and especially the pairs of oral arma- ture pieces. Each adambulacral plate bears prominent tubercles ° for the articulation of stout but short spines. The columns have the pieces arranged with a decided slant outward and distally.
1 Paleontology of New York, vol. 2, 1852, p. 352 and pl. 85, figs. 8-10.
REVISION OF PALEOZOIC STELLEROIDEA. 73
Ambulacral furrows deep, slender and tapering slowly. Ambu- lacral plates unknown. Oculars not present.
Genoholotype.-Palzxaster ( Monaster) giganteus Etheridge, jr. The specific description and the bibliographic references are included in the generic diagnosis.
Restricted to the Lower Marine series of the ‘“ Permo-Carbon- iferous” of New South Wales.
AUSTRALASTER(?) STUTCHBURII (Etheridge, jr.).
Palxaster (Monaster) stutchburit ErHermwee, jr., Mem. Geol. Surv. New South Wales, Pal., No. 5, pt. 2, 1892, p. 73, pl. 18, fig. 1. Monaster stutchburti GreGory, Geol. Mag., dec. 4, vol. 6, 1899, p. 346.
This species is found associated with A. giganteus and its preserva- tion is such that the form is very imperfectly known. In some respects it resembles that species and may prove to be a smaller specimen of it, but until the disk marginals are known the differ- ences will remain obscure.
If A. (?) stutchburw has the large disk marginals of Australaster, it then seemingly will have the essential structure of that genus. Regarding this the writer wrote Professor Etheridge in 1900 and he replied that “axillary plates are not visible in the specimen”’.
Since the abactinal area of A. giganteus is unknown, it is desirable to give here the abactinal structure in A. (?) stutchburti, as it may prove to be congeneric with A. giganteus.
“Abactinal surface moderately convex, bearing several (five or six) rows of small convex polygonal plates, inclusive of the margi- nal pieces, and becoming much crowded at the apices of the rays, where they form oblique rows.” If these plates throughout the rays are as figured by Etheridge for the distal ends, the strongly quincuncial arrangement of the polygonal, closely adjoining plates is another good generic character for Australaster.
PROMOPALAASTERID, new family.
Progressive Phanerozonia with distinct columns of inframar- ginal plates. Interbrachial areas more or less complex, composed either of inframarginals, axillary interbrachials and ambulacrals, or of these with the addition of interbrachial marginals and acces- sory interbrachials, or entirely of adambulacral plates. Ambu- lacrals as a rule opposite, but they may also be slightly alternating. Podial openings through the sutures in the lateral corners of the ambulacral plates, but proximally a few alternate pores may grad- ually pass medially, when there are four columns of podial openings in each ambulacral furrow.
Madreporite abactinal.
Abactinal plates very numerous, generally small, either in dis- tinct columns or rows or without either arrangement. The radial
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and supramarginal columns may be very distinct or may be ob- scured as such. Accessory ossicles always more or less abundantly developed. Contains: Mesopaleasterine. Promopaleasterine. Anorthasterine.
MEHSOPALAMAASTHRIN A, new subfamily.
Palxocomide GREGORY, Treat. Zool., vol. 3, Echinoderma, 1900, p. 254.
Primitive Promopaleasteridz with the interbrachial areas small, composed of one pair of inframarginals, single axillary interbra- chials, and the adambulacral plates.
Contains:
Mesopalexaster, new genus. Spaniaster Schéndorf. Moomaster Schéndorf. Devonaster, new genus.
MESOPALAASTER, new genus. Plates 7-11.
Palxaster (part) of AUTHORS.
? Argaster Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 287: rev. ed., 1868=1870, p. 329. .
Mesopaleaster ScoucueErt, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 24.
Meso=middle, and Palzaster. Not the largest of Palsasters of authors.
Generic characters.—Rays five, slender and tapering. Disk small, with incipient interbrachial arcs.
Abactinal area with distinct columns of radial and supramar- ginal plates, between which are inserted rows of accessory pieces, one or two on each side of the medial columns. In mature specimens the radial columns are less prominent proximally than distally. The accessory columns proximally may also have here and there inserted on each side a smaller piece, when the area between the supramarginals has not only three or five columns of plates but also other additional small plates. The inframarginal columns margin the rays, while the supramarginals lie somewhat inside and above the former. Between the two columns of marginals there may be a row of accessory ambital plates. The arrangement of the plates of the disk appears to be as follows: In the center there is a small plate around which is a first ring of 7 pieces, followed by a sec- ond ring having not Jess than 14 plates, and these are nearly of one size. The medial ray columns terminate on the disk in 5
REVISION OF PALEOZOIC STELLEROIDEA. 9
large radial plates, but inside of the proximal supramarginals there is no basal interradial plate as in Hudsonaster.
Madreporite unknown.
Inframarginal and adambulacral plates as in Hudsonaster, except- ing that two of the former and a single axillary plate are in each interbrachial area. Oral armature so far as preserved adambulacral, consisting of five pairs of basal adambulacrals.
A single, pentagonal, axillary interbrachial plate is present in each area, orad to the two axile inframarginal plates.
Ambulacral grooves deep and almost closed by the adambulacral columns. Ambulacral plates carinate and apparently one to each adambulacral ossicle. Their relation to one another is not definitely determinable, but apparently they are slightly alternate or nearly opposite.
Genoholotype.—Palzxaster shafferi Hall.
Distribution.—The species of Mesopalxaster are restricted to America in the upper portion of the Ordovicic and the lower portion of the Siluric. A species doubtfully referred to this genus occurs in the Lower Devonic of Germany, and another in the Upper Devonic of Maryland.
The following are the species of Mesopalzaster:
M. shafferi (Hall). Middle and upper beds of the Cincinnatic series. Possibly also in the Utica formation of New York.
M. intermedius, new species. Maysville formation.
M. finei (Ulrich). Eden formation.
M. (?) lanceolatus, new species. Utica formation.
M. proavitus, new species. Eden formation.
M. (2?) wilberanus (Meek and Worthen). Richmond series.
M. (?) dubius (Miller and Dyer). Upper Trenton.
M. (?) antiquus (Troost). Upper Trenton.
M. (?) parviusculus (Billmgs). Siluric (Lower Arisaig).
M. (?) cataractensis, new species. Siluric (Cataract formation).
M. grant (Spencer). Siluric (Cataract formation).
M. bellulus (Billings). Siluric (Rochester shale).
M. caractact (Gregory). Caradoc of England.
M. (?) acuminatus (Simonovitsch). Lower Devonic of Germany.
M. (?) clarki (Clarke and Swartz). Upper Devonic (Jennings formation).
Remarks.— Mesopalxaster apparently developed directly out of Hudsonaster in that the single axillary marginal plates are in the former genus in nearly all the species pushed inward (interbrachial) and their former place occupied by the proximal plates of adjoining inframarginal columns. The same generic feature also distinguishes Mesopalaster from Paleaster. Further, in Hudsonaster there are no abactinal accessory ray plates, but in Mesopaleaster one or two more or less completely developed columns are inserted on each side
76 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
of the radial columns or, in other words, between the radials and supramarginals. Between the inframarginal and supramarginal plates in Mesopalxaster there are also either a few incipient accessory plates, which in young specimens are wholly absent, or there is a complete column of these ambital plates. The accessory and axillary inter- brachial plates are additions to the generic structure of Hudsonaster and Palzaster, and further distinguish Mesopalxaster from both. This progression toward a greater number of columns of abactinal plates attains its maximum in Promopalzaster and is most marked in P. magnificus, which has not less than 28 columns at the base of a ray and 5 interbrachial marginal plates in each interbrachial area. The ambulacral furrows, which are very narrow in Hudsonaster, are likewise so in Mesopalexaster, but are wide in Promopalzaster. Spi- nosity, which is practically absent abactinally in Hudsonaster, is developed in Mesopaleaster and very pronounced in some forms of Promopaleaster (P. spinulosus and P.dyeri). This is apparently also true for the spines of the actinal area.
The youthful plate structure of recent species seems to be retained to maturity in Hudsonaster and somewhat so also in the genotype of Mesopaleaster but in Promopalzaster the central area of the disk is occupied by numerous very small plates and no definite arrange- ment is discernible, though this is in large part due to their displace- ment through fossilization. However, it is certain that the basal radials and interradials do not increase nor maintain a relative size as in Hudsonaster and in the genotype of Mesopalzaster (here radials only), but must have diminished to that of the accessory plates from which they are now not distinguishable. From Hudson- aster through Mesopaleaster into Promopalxaster the animals are constantly increasing in size, and this also continues in the species of the latter genus, attaining culmination in P. magnificus and P. dyert.
While the generic abactinal differences between Hudsonaster and Mesopaleaster are easily made out, this is not so readily accom- plished between the latter and Promopaleaster. All of the abactinal generic characters of Mesopalxaster are more pronounced in Pro- mopaleaster excepting that in the former the ambital accessory plates are almost always undeveloped as columns, while in the latter these plates are always well developed in one or more columns.
When the actinal area is shown, Mesopalexaster is at once distin- euished from Promopaleaster in that it has but one axillary inter- brachial plate in each interbrachial area, while the latter has always two or more up to five (=interbrachial marginals) in each area.
Devonaster in some respects is closely related to Mesopalzaster and may be in the line of descent from the latter. However, the disk in Mesopalxaster has far fewer abactinal plates, and there are no distinct interbrachial arcs with numerous small accessory plates
REVISION OF PALEOZOIC STELLEROIDEA. eh
as in Devonaster. The pieces of the radial columns in Mesopalxaster adjom one another and are not separated by intercalary plates, nor are these nearly so numerous between the radial and supramarginal columns as in Devonaster. These accessory plates in Devonaster are also irregularly disposed and not in columns as in Mesopalzaster.
The name Argaster has not been defined nor is it mentioned in such a way that anyone will recognize that Hall intended it for a new genus or subgenus. In addition, its genotype (Asterias antiqua = Mesopale- aster (2?) antiquus) is a poorly known species. Under these circum- stances, and the additional one that the name Argaster never has had any standing as a genus, it should not now be rehabilitated by paleontologists.
MESOPALZASTER SHAFFERI (Hall).
Plate 8, figs. 1, 2.
Palzaster shafferi Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 284; rev. ed., 18681870, p. 326, pl. 9, fig. 1—Mzrerx, Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 66, pl. 4, fig. 1.
Original description.— ‘Body of about medium size composed of five tapering, acutely pointed rays, which, in the specimen examined, measure seven-cights of an inch from the center of the disk to the extremity. The lower side of the ray is formed of two ranges of plates bordering the ambulacral groove. The marginal range consists of moderately convex plates which gradually decrease in size from the base to the extremity of the ray, 22 or 23 in number [not more than 20 exist in any ray of the type-specimen], besides a small terminal one at the angle of the range; each plate of the marginal range is marked on its outer surface by a comparatively large cicatrix for the attachment of a strong spine. The inner range of plates (adam- bulacral) are somewhat smaller, about the same in number, alternat- ing with those of the marginal range; the basal pair (oral plates) are elongate-triangular, and slightly constricted near the middle. Ambulacral areas narrow, composed of a double range of poral plates, which at the middle of the ray are about of equal length and breadth. Pores not observed. [The writer could not make out these plates in the type-specimen and believes those described to be the inner sides of the actinal plates.] Upper surface of the ray composed of three ranges of subnodose plates, the outer ranges bearing a strong spine on each plate; the central range apparently destitute of spmes. No spines have been observed, but the plates are strongly carmate or pointed.”
Emended description.—The largest specimen in the Harris collec- tion measures: R=19 mm., r=5.5 mm., R=3.5r. Another specimen of the same collection: R=16 mm., r=5 mm., R=3.1r. The smallest known specimen in the Vaupel collection: R=6.5 mm.,
78 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
r=2.5 mm., R=2.6r. The type-specimen, which is the largest known example, measures: R=21 mm., r=6 mm., R=3.5r. Width of ray at base in various mature examples 5 mm. to 7 mm.
Rays more or less long, slender, abactinally slightly convex, with marked longitudinal ridges, actinally flat or concave. Disk of medium size, abactinally convex and without interbrachial ares.
Abactinal area of rays occupied by a central range of radial plates, on each side of which there is a range of accessory ossicles which however do not attain the distal portion of the rays. In mature rays there are in the proximal region also inserted a few plates on each side of the intercalary columns. Outside of the latter are the ranges of well-defined supramarginal plates which slightly overlap the inframarginals. The marginal and radial plates are most promi- nent, and all are highly carinate or pomted. There is a single large spine on the apex of all radial and accessory plates and several smaller ones are also arranged around it. The supramarginal plates have numerous granules which bore articulating spines. The plates of the disk can not be clearly made out, but in a small specimen somewhat distorted there appears to be a small central plate sur- rounded by a first ring of 7 ossicles followed by a second ring of 14 plates. These pieces are all nearly of a size. The medial ray columns terminate in 5 large basal radial plates, while inside of the proximal inframarginals there is no large interradial plate as in Hudsonaster incomptus.
Ambital area very illy defined, but in the angles between the large infra- and supramarginal plates there are here and there inserted tiny accessory pieces. In a young individual there are none of these accessory plates.
Madreporite unknown.
Inframarginal plates distinctly granulated, completely inclosing all other abactinal plates and common to both the abactinal and actinal areas. In mature specimens there are from 15 to 20 plates on each side of aray. Laterally each plate has a well-marked small pit, probably the place of attachment for rather strong spines, none of which however have been observed.
Interbrachial areas with single, hexagonal, axillary interbrachial plates.
Adambulacral plates slightly elongate-subquadrangular, of which there are from 18 to 20 on each side of a ray; distally they appear to pass over and to cover completely on the actinal side the inframar- ginal plates. Between the adambulacral columns there is a more or less wide ambulacral furrow. Each adambulacral plate bears on its inner edge a rather thick but short, slightly striate spine and several minute ones. Orad to each axillary interbrachial there is a pair of prominent elongate-triangular adambulacral plates bearing spines,
REVISION OF PALEOZOIC STELLEROIDEA. 79
one of the five pairs constituting a part of the oral armature. Jn other words, the adambulacral columns of adjoining rays are continued around the axillary interbrachials by two modified plates.
Ambulacral grooves deep, nearly closed by the adambulacralia. Ambulacral plates not well shown but apparently carinate, one to each adambulacral ossicle, and whether alternate or opposite can not be stated.
Locality and formation.—In the middle and upper stages of the Cincinnatic group (Ordovicic). The type-specimen (No. 1195, Amer. Mus. Nat. Hist.) was found by Mr. D. H. Shaffer at Cincin- nati, Ohio, probably in the Maysville formation. Mr. Vaupel found a young individual showing the abactinal area (No. 60605, U.S.N.M.); another young one was secured by Mr. Faber (No. 9568, University of Chicago), and Mr. George Oeh found an excellent matured individual preserving the actinal area (now in the Yale Museum), all from the Maysville formation on the hills back of Cincinnati. Two good speci- mens and another small poor one are in the Harris collection of the United States National Museum (No. 59391) and were found in the Waynesville division of the Richmond formation near Waynesville, Ohio.
A small asterid preserving two rays and a portion of the disk is in the United States National Museum collection (No. 23540) and was found by Mr. W. P. Rust in the Utica shales one and a half miles east of Rome, Oneida County, New York. Itis associated with Trinucleus concentricus, Dalmanella testudinaria’ multisecta, and other species. The abactinal area only is shown, and appears to be that of Meso- palzaster shafferr. It does not appear to be a Promopalzxaster because of the fewer columns of abactinal accessory plates, and the axillary structure makes it almost certain that there is here but a single axil- lary interbrachial plate. For the present it may be provisionally referred to this species and attention is thus directed to it so that local collectors may be on the lookout for other material.
Remarks.—This species has actinally much the appearance of Hudsonaster incomptus, but the latter is at once distinguished by not having the five axillary interbrachial plates of Mesopalxaster shaffert. M. (?) parviusculus (Billings) is smaller, with far less plates in all the columns thanin M. shafferi. M. (?) parviusculus and M. grant differ also abactinally and ambitally in the better developed accessory plates.
Cat. Nos. 60605, 59391, 23540, U.S.N.M.
MESOPALZASTER INTERMEDIUS, new species. Plate 9, fig. 4. This species is perplexing in its generic construction because of its intermediate or transitional characters on the one hand (but least)
to Hudsonaster, and on the other (more decidedly) to Mesopaleaster 50601°—Bull, 88—15——6
80 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
and prophetic of Promopalzaster in the conspicuous ambulacral furrows.
Rays long and slender, elongate-petaloid, disk small. R=about 14 mm., r=4 mm.
The interbrachial areas each have but a single, large, finely granu- lated, axillary plate that margins the axils, and in this agree best with Hudsonaster, but the rest of the known skeleton is that of Meso- paleaster. In the former genus the ambulacral furrows are always very narrow and the ambulacralia are rarely seen, while in J. intermedius the furrows are wide and the ossicles are rather like those of Promopaleaster, though the same kind of ambulacralia is also known in Mesopaleaster. Orad to the axillary plates there were two small oral armature pieces that belong to the adambulacral columns. These are not now present in the specimen, but the distinct and large facet of the proximal side of the axillaries leaves no doubt on this construction.
Inframarginal columns well-developed proximally, though never very prominent, and becoming rapidly smaller distally. The four proximal pieces are the largest, beyond which there are at least 14 other ossicles, and all are closely in contact and alternate with the adambulacrals. Another feature of these inframarginals is that not more than six can be seen from the actinal surface, while the rest pass on to the sides and distally even somewhat over to the abactinal area. All of the plates are finely granulated.
Adambulacral columns the most prominent of the actinal skeleton, margining the distal half of the rays, and in the proximal portion pass more and more inside of the inframarginals, diminishing slowly in size and finally depressed beneath the ‘axillaries. ‘There are 22 plates in a column, all more coarsely granulated than the inframar- cinals, largest and most transverse near mid-length of the rays, and all are drawn out inwardly into blunt points that adjoin the high ridges of the ambulacralia. Therefore the adambulacral and the adjacent ambulacral columns have the ossicles directly opposite one another, but the adjacent ambulacral rows are slightly alternating.
Ambulacral furrows conspicuous and wide, widest in the proximal third but converging somewhat quickly in the mouth area and far more gradually distally. Therefore the furrows are elongate-petaloid inshape. There are about 20 ambulacralia in a column. Proximally the columns unite around and beneath the small adambulacral oral armature pieces. Ambulacralia square to transversely rectangular, each with a high L-shaped crest that laterally adjoins the points of the adambulacrals and medially bends orally. Podial openings large between the corners of pairs of ambulacrals and adambulacrals. There is a well-developed groove down the center of the ambulacral furrows.
REVISION OF PALEOZOIC STELLEROIDEA. 81
Abactinal area unknown, but probably that of Mesopalaster and nearest to M. shafferi.
Formation and locality.—The holotype was found by Faber in the Maysville formation at Cincinnati, Ohio, about 350 feet above the Ohio River. The type is in the University of Chicago Museum (No. 9575).
Remarks.—This interesting species need be compared only with M. shafferr. It differs in having the axillaries in the axils of the rays and not inside the basal inframarginals as in the latter form. Then in M. shafferr the inframarginals are actinal in position throughout, while in M. intermedius they are more on the sides. Further, in the new form the ambulacral furrows are well developed with large ambulacralia, while in J. shafferi the furrows are narrow and the ossicles rarely seen.
MESOPALAASTER FINEI (Ulrich). Plate 7, fig. 5; plate 9, fig. 5.
Palzaster finei UtRicn, Journ. Cincinnati Soc. Nat. Hist., vol. 2, 1879, p. 19, pl. 7, figs. 15-15b.
Original description.—‘‘ Small; rays five, of medium length, rather broad, pointed and narrower where they are attached to the much contracted body [probably due to distortion], than they are about the center of their length.
“Dorsal side of rays composed of four [about seven, the supra- and inframarginals, radials, and two intercalary columns] rows of pieces, that are quite close [¢] fitting, as wide as long, from 12 to 14 in each row, and increase in size inward to the disk, which is composed of irregularly shaped and prominent pieces, some of which are smaller and others larger than those composing the rays; the pieces in the marginal rows [four columns infra- and supramarginals] are more prominent than the two [there are three, radials and two intercalary] rows between them, and have a small pit in the center, probably for the articulation of a spine [all of the plates originally bere several short slender spines]. Madreporiform body rather small, circular, very prominent, and marked by strong striz, which become more numerous toward the margin by intercalation.
“Marginal [inframarginal] pieces on the ventral surface, convex, quite as long as wide, and numbering in different specimens on each side from 11 to 12 [probably not more than 8 or 9]; the piece at the junction of the rays is three times as large as any other of the series, subcircular and very convex. [It appears that this large plate is an axillary interbrachial since upon it proximally rest two basal plates of the inframarginal series. ]
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‘ Adambulacral plates more prominent [less prominent than the inframarginal plates], slightly wider than long, and numbering, on each side, from 9 to 10 [probably not less than 16 in each column]. | Ambulacral pieces a little wider than long, not alternating with the adambulacral plates, and each provided with a rather sharp ridge across most of its width.
“There are 10 oral plates [oral armature] formed by the junction of the adambulacral rows, which in form and size are scarcely dis- tinguishable from the other plates of those series.
“Greatest breadth measuring between the opposite extremities of the rays, 0.7 inch; breadth of rays at their inner ends, 0.1 inch; length of same, 0.3 inch; diameter of madreporiform piece, 0.02 inch,”
Formation and locality—This small species appears to be common at a very restricted horizon near the base of the Eden formation (Fulton beds), exposed at low water mark in the Ohio River in the eastern portion of Cincinnati, Ohio.
Remarks.—Not one of the twenty examples seen is well preserved and all the plates are more or less separated. The general structure seems to be that of Mesopaleaster. The composition of the axillary area is not positively ascertainable but one specimen shows what appears to be a large axillary interbrachial plate (see pl. 7, fig. 5), distally surmounted by two somewhat smaller inframarginals. ‘This is probably the true structure since it is so in all the smaller Meso- palwasters, as M. lanceolatus, M. parviusculus, M. granti, and M. proavitus.
The differences between MM. finet and M. proavitus are not great. The former is a smaller species with less plates in all of the ranges, more prominent axillary inframarginal and axillary interbrachial plates, and is also found at a lower geological horizon. M. finet differs from the small species M. parviusculus of the earliest Siluric in having more plates in all of the columns. MM. granti is a larger species and with smaller and more numerous plates than in M. finer. M. lanceolatus is probably the most closely related to M. finei but is distinguished abactinally by the diagonal arrangement of the plates on each side of the radial columns.
Cat. No. 60604, U.S.N.M.
MESOPALZASTER(?) LANCEOLATUS, new species. Plate 4, fig. 3.
Measurements: R=4.5 mm., r=1.3 mm., R=3r.
Rays short, stout, distinctly lanceolate actinally and rapidly ta- pering abactinally. Disk comparatively large, abactinally convex. Interbrachial ares distinct but small.
Abactinally the disk has a ring of large, strongly stellate plates which are the basal plates of the radial and supramarginal columns.
REVISION OF PALEOZOIC STELLEROIDEA. 83
Inside the ring the plates can not be made out, due to the small size of the specimen. Rays each with a column of radials and two supra- marginals between which are inserted columns of diagonally arranged accessory plates. A few ambital accessory plates are probably also present. The arrangement of the ossicles on the abactinal areas of the rays is like that in Promopalexaster magnificus.
Madreporite small, subconical, situated near the edge of the disk, depressed between adjoining basal plates and marked by 10 or 11 sharp, somewhat spirally arranged ridges.
Inframarginal plates large, about six in each column proximal to the very large single axillary interbrachial plate. These columns in the distal half can not beseen actinally as they pass over on the dorsal side.
Axillary interbrachial plates large, one in each axil, and not com- pletely inclosed outwardly by the basal inframarginals. In this character the form is still in the Hudsonaster stage.
Adambulacral plates small, subquadrangular, with 16 plates in each column. The plates of the adambulacral oral armature are larger and wedge-shaped, and are situated directly inside of the axillary interbrachial plates.
Ambulacral plates one to each adambulacral, apparently opposite and with proximally converging ridges. Podial openings apparently along the outer edge between the sutures of adjoining plates.
Formation and locality—Two specimens were found by the late Prof. Charles E. Beecher near Rome, New York, in the Triarthrus bed of the Utica formation that preserves the entire ventral anatomy of these trilobites. The cotypes are in the Museum of Yale University. Mr. W.S. Valiant in a letter states that they are common in a layer 2 to 3 inches above the Triarthrus bed.
Remarks.—This species is most closely related to M. finei, from which it is readily distinguished abactinally. Here there are more and smaller plates than in MV. lanceolatus, the interpolated plates are arranged diagonally and not radially as in MV. finei, while the basal plates of the former are apparently much larger and are strongly stel- late. Actinally there are in If. lanceolatus more adambulacral plates in each column, although the specimens are only half the size of M/.
fine.
R=18 mm., r=about 4.5 mm. The specimens are distorted, however, and no exact measurements can be given.
On the distal abactinal portion of the rays the infra- and supra- marginal and radial plates closely adjoin. Proximally, however, between the two marginal series there is inserted a column of inter- calary plates gradually increasing in size and two other similar rows of plates are placed between the supramarginal and radial columns.
MESOPALZ/ASTER PROAVITUS, new species.
84 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
There are therefore at the base of the rays no less than 11 columns of plates. The radial columns proximally have a tendency to become less distinct and indistinguishable from the accessory pieces. The plates in general are highly convex, granular and abundantly spme- bearing. There are not less than 20 plates in each supramarginal series.
Madreporite highly convex, broadly oval in outline and radially striated.
Inframarginal plates finely granular, highly convex, subquad- rangular in outline and increasing in size slowly proximally. About 23 in each column.
Adambulacral plates like the inframarginals but not increasing much in size proximally, with about 29 in each column. As in other species of this genus, each plate bears three prominent spines, two Jaterally and one prabwincralle.
Ambulacral plates one to each adambulacral plate, and with a sharp ridge which medially bends abruptly orally. Podial openings as in other forms of Mesopalzaster.
Interbrachial areas occupied by single axillary interbrachial plates upon each of which rest proximally two axillary inframarginals.
The specimens are not figured, as an illustration can not readily be made.
Formation and locality—Three more or less entire specimens and fragments of four rays were found by Dr. E. O. Ulrich in the Eden shale exposed back of Covington, Kentucky, at an horizon about 100 feet above low water in the Ohio River. All the specimens are now in the Herzer collection, a part of the late Prof. James Hall’s private collection, recently purchased by the University of Chicago.
both have 11 columns of abactinal plates, including the marginals, and they are nearly alike actinally. However, the former is twice as large and appears to have more conspicuous radial and supramarginal columns than the latter. These differences and the further fact that one occurs in the Utica and the other in the earliest Siluric will serve to distinguish the two species for the present. MJ. proavitus may prove to be identical with MM. (?) wilberanus, which see for further remarks. MESOPALAASTER (?) WILBERANUS (Meek and Worthen). Petraster wilberianus MerK and WorrHEN, Proc. Acad. Nat. Sci., Philadelphia,
for 1861; vol. 13, 1862, p. 142. Palzaster wilberanus Hauu, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 285; rev. ed., 18681870, p. 328.
Original description‘ This beautiful starfish resembles rather closely Petraster rigidus of Billings,’ but is smaller, and has more
1 Decade 3, Org. Rem. Canada, pl. 9, fig. 3a.
REVISION OF PALEOZOIC STELLEROIDEA. 85
slender rays, with more angular spaces between. It also differs in having but two ranges of plates on each side of the ambulacral grooves, on the under side, instead of three. These pieces are about of the same size in each row, and sometimes appear to alternate; they are all rather prominent, and those of the outer range project a little laterally in the form of small nodes. Toward the outer extremities of the rays, however, the lateral ranges are contracted behind the others, so as to be scarcely visible from below. About 23 of these pieces may be counted on each side of the ambulacral furrow in each ray. The ambulacral furrows are very narrow, and indeed seem to be closed toward the extremities of the rays, by the gradual approximation of the inner rows of pieces on each side, which alter- nate and appear to fit together.
‘Our specimen only shows the under side, but along the outer margins of two of the rays, there is some appearance either of the overlapping of some of the dorsal parts by pressure, or of a slightly developed disk. This part does not seem to have any distinct range of marginal plates, but appears to be made up of small pieces, covered with granules, or bases of small spines.
“We take pleasure in dedicating this interesting species to Prof. C. D. Wilber, of the Illinois State Normal School, to whom we are indebted for the use of the only specimen we have seen.
‘““Greatest diameter about 1 inch; smaller diameter 0.33 inch.
“‘ Locality and position.—Oswego, Kendall County, Illinois, in rocks of the age of the Trenton or Hudson River Group of the New York series.”” Probably equivalent to the Richmond beds of the highest Ordovicic. The whereabouts of the type-specimen is not known.
Remarks.—Hall pointed out that this species is not a Petraster because P. wilberanus has but two columns of plates on each side of the ambulacral groove, while Petraster has in addition ‘‘a few disk plates on the ventral side.’”’ He therefore referred it to Paleaster. However, Meek and Worthen describe the abactinal area as having no “distinct range of marginal plates, but appears to be made up of small pieces, covered with granules, or bases of small spines.”” The characters as far as mentioned appear to be those of Mesopalexaster. Should there prove to be in P. wilberanus single axillary interbrachial plates, then all of the characters will be in harmony with Mesopalex- aster and M. proavitus may prove to be a synonym of it. This can not be proven at present since we have not been able to locate the type-specimen.
MESOPALZASTER (?) DUBIUS (Miller and Dyer). Palzaster dubius M1tLER and Dyer, Cont. to Pal., No. 2, 1878, p. 5, pl. 4, fig. 8. Original description.—< Pentagonal; rays longer than the diameter
of the body, and uniformly tapering. The ambulacral groove is sharply angular in the middle, formed by two series of plates having
86 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
their ends together in such manner as to make an angular gutter [the plates of adjoining columns are arranged practically opposite]. The length of these plates is three times as great as the diameter. The plates are placed with the length across the rays. There are 15 plates on each side of the groove in each ray, in the length of one quarter of an inch [this is an error as there are about 20 plates in a column]. The diameter of the body is three-tenths of an inch.
“This species is founded upon a single specimen, in Mr. Dyer’s collection, which shows only part of the ventral side. The ends of the rays [most of the adambulacrals] and marginal plates are destroyed [each axillary area appears to bear one axillary mterbrachial plate]. The parts preserved seem to distinguish it from any species hitherto described.”
Formation and locality—In the original description the locality is given as Cincinnati, Ohio, but the character of the rock shows that it is from the uppermost portion of the Trenton limestone, probably opposite Cincinnati, in the river quarries at Ludlow, Kentucky. The type (No. 25) is in the Museum of Comparative Zoélogy, Harvard University.
Remarks.—This specimen preserves well the very wide ambulacrals but almost no other plates. The adambulacrals are nearly all removed and but very little is to be seen of the marginals. In three of the axillary areas there are single interbrachial plates, one of the essential features of Mesopaleaster. It is referred to this genus provisionally, as nothing is known of the abactinal side.
MESOPALZASTER (?) ANTIQUUS (Troost).
Asterias antiqua Troost (not Hisinger 1837), Trans. Geol. Soc. Penn., vol. 1, 1835, p- 232, pl. 10, fig. 9; Proc. Amer. Assoc. Adv. Sci., vol. 2, 1850, p. 59 (cat. name).
Petraster (?) antiqua SHumarp, Trans. St. Louis Acad. Sci., vol. 2, 1866, p. 386 (catalogue name).
Palxaster (Argaster) antiqua Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 287; rev. ed., 18681870, p. 329.
Palzaster antiquus Mrtter, N. Amer. Geol. Pal., 1889, p. 265 (cat. name).
Argaster antiqua Greaory, Geol. Mag., dec. 4, vol. 6, 1899, p. 345 (gen. ref.).
Palzaster antiqua Wood, Bull. U. 8. Nat. Mus., No. 64, 1909, p. 105, pl. 8, fig. 1.
Although this is the first recorded American fossil starfish, very little is known about it and that little is mostly of a misleading nature. The specimen lies on a limestone slab and is very badly weather- worn or it may have been treated with hydrochloric acid so that now it is nothing more than a polished section of a starfish. An illustra- tion that will show its actual characters can not be made.
Professor Hall errs in stating that Asterias antiqua has ‘‘ambu- lacral grooves occupied by a single row of subquadrate ossicula, which extend across and alternate with the adambulacral plates of each mar- gin. * * * Tt is possible that this character may prove to be of generic importance.” It may have been this character on which
REVISION OF PALEOZOIC STELLEROIDEA. 87
Hall thought of basing the genus Argaster, but he does not character- ize it nor even mention that the name in parenthesis is intended as a new term with Asterias antiqua Troost as the genotype. This species, like all other Paleozoic starfishes, has double columns of ambulacral plates. This the specimen clearly demonstrates on the edge of the slab where the distal parts of the rays are broken away. Argaster should therefore be regarded as a nomen nudum, and should A. antiqua prove to be a Mesopaleaster, it should not be made to displace this genus.
Asterias antiqua has about 15 inframarginal plates in each column and about 32 in each adambulacral column. Two of the latter plates meet as usual in a pair of triangular oral armature pieces.
Each axil is occupied by two large, quadrangular, basa] inframar- marginal plates. Between these proximally there is a large, widely triangular, interbrachial plate the apex of which may or may not attain the margin. Proximal to each axillary imterbrachial plate and between the four or five pairs of axillary adambulacral plates, there is in the specimen an open space in each of the five areas. What additional plates, if any, occupied this area is not determinable. It may be that the axillary interbrachial plates occupied the entira interbrachial areas and that the present hiatus is due to the worn condition of the specimen. This appears to be the most natural interpretation as it is the normal interbrachial structure of Mesopa- leaster. In Promopalzaster there are always two, three, five, or seven interbrachial marginal plates in each area, a fact which excludes Aste- rias antiqua from that genus.
The abactinal area is not visible, but many of these plates are squeezed beyond the inframarginals, showing the presence of num- erous small plates recalling Mesopalxaster and Promopaleaster.
Formation and locality.—Troost’s label reads: ‘‘Lower limestone on Harpeth River, Davidson County, Tennessee.” His manuscript reads: ‘“‘It was found * * * on Harpeth River, Davidson County, Tennessee. Associated with Spirifer lynx [Platystrophia biforata], Cyathophlyllla [=Streptelasma], Orthis [testudinaria], ete.” This is apparently the same horizon as that about the city reservoir m Nashville, which is now regarded as of Upper Trenton (Catheys) age. The specimen is in the United States National Museum.
Cat. No. 39914, U.S.N.M.
MESOPALZASTER(?) PARVIUSCULUS (Billings). Plate 9, fig. 1. Palxaster parviusculus BruuinGs, Canadian Nat. and Geol., vol. 5, 1860, p. 69,
figure.—Dawson, Acadian Geology, 2d ed., 1868, p. 594, fig. 197.—Hupson, Bull. N. Y. State Mus., No. 164, 1913, pls. 1-4.
Original description—‘‘The specimen is about six lines in diameter. The rays are two lines in length and one and a half in width at the
88 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
base, tapering at an angle of a little less than 45°. The five oral plates are subpentagonal, about half a line in width. The first adambulacral plates of each pair of adjacent rays are in contact with each other outside of the oral plates, and not completely. sep- arated as they are in P. niagarensis. There are six or seven adam- bulacral plates on each side of the ambulacral groove m each ray, and they gradually decrease in size from the oral plate outward to the point of the ray. The width of the ambulacral groove is equal to one-third the width of the ray and consequently the adambu- lacral rows of plates are also each equal to one-third the whole width of the ray. In each groove there are two rows of small and appar- ently nearly square ambulacral plates, 12 or 14 in each row, and they seem to be contmued round on the inner margin of the oral plates; the mouth is about one line wide.”
Emended description.—Measurements: R=6 mm., r=2.5 mm., R=2.4r. Width of ray at base 3 mm.
Rays short, stout, tapermg rapidly. Disk comparatively large, and without imterbrachial ares.
Abactinal area unknown.
Inframarginal plates at the base of the rays very large and thick, highly convex, diminishing rapidly distally, usually quadrangular in form and seven on each side of a ray.
Just within each axil, inside of the basal inframarginals, there is a single, large, very convex, pentagonal, axillary interbrachial plate.
Adambulacral plates gradually sinking below the inframarginals proximally, convex and quadrangular in form. There are 13 plates in each column adjoining the very narrow ambulacral furrow, or nearly two plates to each inframarginal ossicle. Two of these plates (oral armature) are situated in front of each axillary inter- brachial, uniting the adambulacral columns of adjoiming rays.
Ambulacral plates unknown.
Locality and formation.—The type-specimen, a natural mold, was found by Rev. D. Honeyman in the Lower Arisaig of the Siluric (=Clinton) rocks at Arisaig, Nova Scotia. The holotype is in Redpath Museum of McGill University, Montreal, Canada, and the illustration is taken from a gutta-percha squeeze kindly made for the United States National Museum by Sir William Dawson.
Remarks.—The general actinal appearance of this little asterid reminds one much of Palzaster and Hudsonaster. It differs, however, at once in a little detail of considerable importance, in that each axillary area has three plates, while in Palzaster and Hudsonaster there is but one. In other words, the large axillary plate of those genera has in M. (?) parviusculus been pushed orally and is here an interbrachial plate, while the axils of the rays are occupied by two basal inframarginal plates. For further remarks on this species see M. granti (Spencer).
REVISION OF PALEOZOIC STELLEROIDEA. 89
So long as the abactinal area of I. (?) parviusculus remains unknown its generic position will be doubtful. For the present its relations appear to be nearest to Mesopalxaster and to M. (?) cata- ractensis.
Cat. No. 60620, U.S.N.M.
MESOPALZASTER (?) CATARACTENSIS, new species.
Plate 9, fig. 2.
The specimen of this species has been confused with Jf. (?) granti, from which it differs in being smaller and in having far fewer plates in the columns. The actinal side of M. (?) cataractensis alone is known, while of MZ. (?) granti only the abactinal, but even so the above comparison can still be made because the size of plates is relatively about the same in species of Mesopaleaster.
Measurements: R=9 mm., r=3 mm., R=3r.
The species is most closely related to M. (?) parviusculus, but differs in being larger with more plates in the columns. Of M. (?) cataractensis only the actinal side is known, with 12 to 13 plates in each inframarginal column (7 in M. (?) parviusculus) and about 19 in the adambulacrals (13 in M. (?) parviusculus). Then the inframarginals increase very rapidly in size proximally, while in M. (2) cataractensis there is but little enlargement.
A single small, pentagonal, axillary interbrachial plate occurs in each area immediately beneath the basal inframarginals. These are much smaller relatively than those in M. (?) parviusculus.
Ambulacral plates unknown. Ambulacral furrows deep, nearly completely closed by the adambulacral columns.
Formation and locality—In the base of the Siluric (Cataract for- mation) at Hamilton, Ontario. The holotype was found by Mr. Elhott near the city reservoir and is in the collection of the Hamilton Natural History Society. It was loaned to the writer by the late Col. Charles Coote Grant.
MESOPALZ ASTER GRANTI (Spencer). Plate 9, fig. 3.
Palxaster granti SPENcER, Bull. Mus. Univ. Missouri, No. 1, 1884, p. 53, pl. 7, fig. 1.
Original deseription.—‘ Body stellate and small with short arms, about 2 centimeters across; disk less than 1 centimeter wide, and apparently formed by the junction of the rays; rays 5 millimeters wide at base, tapering slowly, and terminating in rounded extrem- ities, at about 8 millimeters from junction of their base with the disk; upper surface of rays composed of 5 [not less than 9 in mature specimens at mid-length of rays] ranges of highly convex or tuberculi- form plates (the marginal [supramarginal] and ventral [inframarginal]
90 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
rows being the most conspicuous) and separated from each other by minute plates (becoming fewer on approaching the extremities of the rays).
“The ellipsoid [supra] marginal tuberculiform plates number about 12 [20 in mature examples] for each complete side of the rays, and the central range [radial] is composed of a similar number, but in form these plates are more circular. The disk between the ter- minal central [radial] row of plates of the rays is crushed and struct- ureless, except a slight elevation in the center. The terminal [proxi- mal] plates of the marginal series are larger than the others of the range. The madreporiform tubercle is of a spherical form and rela- tively large, being nearly 2 millimeters in diameter, and is situated at the axil of two rays. Both the tuberculiform plates and the madreporiform tubercle have a granulated surface.
“The ventral side is unknown.
Emended description.—A mature specimen measures: R=16 mm., r=5 mm., R=3.3r.
Rays short, stout, tapering rapidly, and with very small inter- brachial ares.
Abactinal area of disk unknown. Along the center of each ray there is a radial column of small, highly convex plates bounded on each side, at about the mid-length of the rays, by two columns of smaller, strongly tumid, accessory plates. The radial column is, however, not distinctly differentiated from those adjoinmg. Out- side of these are the supramarginal columns, each with about 20 plates which are larger and more easily distinguished than the radial plates. Distally the rays have only the ossicles of the infra- and supramarginal and radial columns, with none of the accessory plates as yet developed.
Ambital area with one column of very small accessory plates like the marginal plates on each side of them. These accessory pieces disappear before attaining the apex of the rays.
Madreporite spherical in form and relatively large, nearly 2 milli- meters in diameter, and situated at the axil of two rays between two adjoining supramarginal columns.
Formation and locality—From the Cataract formation, the basal deposits of the Siluric system, near the reservoir in the city of Hamilton, Ontario. Col. Charles C. Grant, after whom the spe- cies is named, discovered most of the specimens, which are six in number, two in the Spencer collection, now destroyed by fire, one in the Redpath Museum of McGill University, Montreal, another in the Geological Survey of Canada at Ottawa, and two in the Grant collection, one of which has generously been donated to Yale University.
Remarks.—This species is apparently closely related to M. bel- lulus, which see for comparison.
REVISION OF PALEOZOIC STELLEROIDEA. 91
MESOPALZZASTER BELLULUS (Billings). Text fig. 7.
Petraster bellulus Buuuinas, Geol. Surv. Canada, Pal. Foss., vol. 1, 1865, p. 393, fig. 368.—Miuuer, N. Amer. Geol. Pal., 1889, p. 269, fig. 389.
Original description. Deeply stellate, about 18 lines across; disk 5 lines wide; width of rays, at the base, half the width of the disk, uniformly tapering to their extremities; ambulacral grooves, narrow and deep, with about 30 adambulacral plates on each side. These plates are strongly convex and nearly square [distally, but proximally are wider than long]. Outside of these there is a row of [about 21 infra] marginal plates, which appear to [actually do] extend to the extremities of the rays, but on this point there is some doubt, as the specimen is not perfect. [The four proximal pieces increase rapidly in size so that they are considerably larger than the others. AJL of the actinal plates are granular.] There » appear to be one or two [there is but one & “AMM, axillary] small disk plates between the oe [basal adjoming infra] marginal and ad- ambulacral plates just outside of the oral angles.
“Locality and formation.—Township of Grimsby [Ontario]; in the Niagara shale [= Rochester shale].
“Collector.—Johnson Pettit, Esq., Fie. 7.—THE onigtvat riguRE or Mr- Grimsby.” The holotype is in the Vic- see eee toria Memorial Museum, Ottawa, Canada = men mas sm too MucH SHALE (No. 2665). ADHERING TO IT AND BESIDES IS CON-
SIDERABLY DISTORTED, PREVENTING Remarks.—The holotype and only ms see sansractormy puoro-
known specimen of this species was seen ¢**7"*?-
by the writer at Ottawa, and has now been freed from the rock so that the abactinal side can also be studied. The generic charac- ters are those of Mesopaleaster and one is impressed at once by the almost specific identity of the abactinal side of the specimen with that of M. granti. However, as the specimens show slight differ- ences and come from different Siluric formations, it is thought best to recognize them as distinct species. Morcover, the actinal side of M. granti is still unknown.
Abactinally all of the skeletal pieces are of about the same size, small, each ossicle irregular in outline, and more or less stellate. There are about 17 in the length of one-half inch. This skeleton is more or less disturbed and it is impossible to clean off all the adhering shale, so that it is difficult to make out the detailed arrangement. The following, however, can be made out: There is no true disk as in Petrasier, and the parts that appear as such are either adhering shale or displaced ossicles due to distortion during sedimentation,
ra
92 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Distally the rays have columns of small radial pieces, and outside of these are the two supramarginal rows. Proximally between these primary columns there appear accessory pieces, one column of which wedge in between the radials and supramarginals and from one to three between the latter and the inframarginals. In this way finally as many as 13 columns can be counted at the base of a ray.
The madreporite is situated near the margin between adjoining supramarginal columns, and is conspicuously protruded and large when compared with the small adjacent ossicles. It is a large, radially striate, irregularly circular plate about six times larger than the adjoining pieces.
MESOPAL/ASTER CARACTACI (Gregory). Plate 9, fig. 6; plate 11, fig. 1.
Palzaster caractact SALTER, Cat. Foss. Mus. Practical Geology, 1865, p. 30 (nomen nudum).—NicHotson and Erxerimeer, Mon. Silurian Foss. Girvan Dist., Ayrshire, fasc. 3, 1880, p. 321 (no description)—Grecory, Geol. Mag., dec. 4, vol. 6, 1899, p. 344.—ScHGnporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 227.
Protopalzaster caractaci SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Palzontogr. Soc. for 1913), 1914, pp. 21, 30, pl. 1, fig. 5.
Remarks.—The writer was greatly pleased to receive from Dr. F. A. Bather of the British Museum wax squeezes of the type-specimens, because they clearly show that the genus Mesopalzaster is present in Europe. JM. caractaci has its closest relationship in JM. shafferi, the genotype of Mesopalexaster. The differences are easily to be seen on the abactinal side, as illustrated in this work.
Rays long and slender, abactinally flattened. R=12.5 mm., r=3.8 mm., R=3.3r. Radialia small and no larger than the pieces of the accessory columns on either side of them; the former alternate in position with the pieces of the latter and all of them are more or less spicular in outline. Basal radials slightly larger than the others. The ossicles of the supramarginal columns large and solid, the most prominent of the abactinal side, very large proximally and exceedingly small distally; there are about 14 in a column. Basal inframarginals most conspicuous of all abactinal plates, with each pair occupying the axils, and together with the smaller basal radialia form a ring bounding the disk. The disk has fallen in but still shows a few small pointed plates.
‘““Madreporite is large, and placed close by one of the interradial angles’”’ (Gregory).
Inframarginal ossicles almost smooth, large and prominent proxi- mally, decreasing rapidly in size so that not more than 9 can be seen actinally, where the tiny pieces pass somewhat over to the abactinal surface, or better the lateral sides; Gregory states that there are 12 ina column. The basal pieces of adjacent columns do not as a rule touch one another in the axils.
REVISION OF PALEOZOIC STELLEROIDEA. 93
Interbrachial areas with single, large, hexagonal, axillary inter- brachial plates.
Adambulacral pieces quadrangular, fairly uniform in size for two- - thirds the length of the rays and then become gradually smaller distally; there are about 15 in a column. A peculiarity of this species is that the ambulacralia do not continue around the axillary interbrachials, but cease with the basal inframarginals. There are, therefore, in M. caractaci no adambulacral oral armature pieces.
Ambulacral furrows moderately wide, with as many rectangular ambulacralia as there are adambulacrals, plus probably four more in each column, and these continue around the axillary interbrachial. Therefore, the oral armature consists entirely of ambulacralia. All of these ossicles are directly opposite one another and have high medial crests that are continuous across the ambulacral furrow. Podial openings large laterally between the plates and the adambu- lacrals.
Locality and formation.—Caradoc sandstone, Soudley quarry, Church Stretton, England. The holotype, a split nodule, is in the British Museum (Natural History), No. 48206; wax squeezes from which the photographs have been made are in the United States National Museum. Other specimens, Bather states, are in the Museum of Practical Geology, London; these are from Marshbrook and occur at a somewhat higher geological level.
Remarks.—Gregory wrote in 1899 that ‘‘the nearest ally of this species is P. matutina (Hall),” but the illustrations here presented will show that the relationship is with Mesopalxaster shafferi and not with Hudsonaster matutinus.
Cat. No. 60606, U.S.N.M.
MESOPALZASTER (?) ACUMINATUS (Simonovitsch).
Asterias acuminatus Stmonovirscu, Sitzb. d. mat.-naturw. Classe Akad. Wiss., Wien, vol. 64, Abt. 1, 1871, p. 100, pl. 3, figs. 2-2d. Asterias acuminata Scuénvorr, Paleontographica, vol. 56, 1909, pp. 72, 109, pl. 11, figs. 7, 8—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 32, pl. 5, figs. 4, 5. Roemeraster (?) acuminatus Srirrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 154. Actinally this small and slender species is nearly in harmony with the generic characters of Palxaster and Hudsonaster, differing only in that the axillary interbrachial plates barely extend to the margin of the disk, while in those genera they are prominent and marginal in the axils. In Asterias acuminatus they are as yet not crowded so far orally as in most species of Mesopalxaster. It is a difference of degree, not of kind; therefore this species has more the actinal character of Mesopaleaster than Hudsonaster. Ambulacral plates unknown. Abactinally Simonovitsch’s species is said to have six columns of tumid plates, all alike and persisting throughout the rays. If the
94 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
outermost columns of each ray are regarded as the inframarginals and the ones immediately inside as supramarginals, two medial columns remain to be homologized with those in Mesopalezaster. It Simonovitsch is correct, then by this interpretation there are two columns between the supramarginals. Both can not be radials and to regard one as such will leave a unilateral and apparently an unnatural development. If five or seven columns of abactinal plates were present, this species would be in harmony with Mesopalxaster. Since Simono- vitsch’s work is of the best, we have at present the only alternative of supposing that the radials in Asterias acuminatus are suppressed and that its two medial columns are homologous with the intercalary abactinal plates of other starfishes. Among Paleozoic asterids this development is rare and is found only in Encrinaster and Palzaster. In that event, A. acuminatus is not a Mesopalzaster.
A single example of this species was found in the Lower Devonic (probably Upper Coblenzian) near Braubach, Germany.
In his revision of the Lower Devonic starfishes of Germany, Schondorf was not able to discover the whereabouts of the type-speci- men and therefore had to leave this species as determined by Simono- vitsch. The former states that actinally the structure reminds one of Spaniaster latiscutatus, the genotype of Spaniaster, and closely related to Mesopaleaster. For further remarks see Spaniaster.
MESOPALZASTER (?) CLARKI (Clarke and Swartz). Plate 10, figs. 1, 2.
Palxaster clarki CLARKE and Swartz, Maryland Geol. Surv., Upper Devonian, 1913, p. 548, pl. 46, figs. 3,4.
Original description—‘‘This species is represented in the collec- tions by a single specimen affording a pretty sharp cast of both sides of a very regular and complete individual. In general structure and appearance the species is quite similar, especially on the oral surface, to Palzaster eucharis Hall of the sandy Hamilton shales of central New York, but the latter is a much larger form.
“The disk is small, rays long and slender, thecal plates all promi- nently developed. The ambulacral surfaces are represented only by a narrow linear depression beneath which the ambulacral plates are concealed. These depressions are bordered by thickened and somewhat elevated quadrangular or pentangular adambulacra. The marginal plates are in single rows, much thickened, with generally quadrangular outline and convex surface, each projecting on the margin of the ray. At each axilla is a single pear-shaped plate with its apex outward, these plates being the largest in the individual. The abactinal surface is tessellated by rows of strong convex plates of similar size to the mar- ginal plates. Of these there are three rows, a median row of narrow oval ones between the ends of which are interlocked the edges of the much larger plates of the lateral rows which are highly convex and
REVISION OF PALEOZOIC STELLEROIDEA. 95
thickened in the center and greatly depressed tothesutures. Thuseach plate has a cushioned surface. Between the ends of each plate of the middle row are two minute accessory plates lying in the angles at which the lateral plates enter. At the base of each ray and upon the disk is a single large plate whose surface rises into a high clavate node. Between each two of these is one of
less height. The central portion of
the aboral area is destroyed and no ih
trace of madrepore is seen. M “The width of this specimen from -@Caq _%
tip to tip is 33 mm. A ees “Occurrence: Jennings formation, ee
Chemung members Yellow sandstone on the road northeast of Oakland, yee Garrett County [Maryland], where it is associated with Spirifer disjunctus. “Collection: Maryland Geological Survey.” Fic. 8.—SPANIASTER LATISCUTATUS, AFTER Remarks.—This clearly determined Sea cnen carn Glee OF species is a late survival of early THE ABACTINAL PLATES. @, PRESUMABLE
Pal : siti forid Th POSITION OF ANUS; Ce, CENTRAL PLATE; aleozol1ce primitive asterids. @ Jn, BASAL INTERRADIALIA; mdp, PROBABLE
characters so far as determinable in position or MADREPORITE; mo, SUPRAMAR- the natural mold are those of Meso- CS) Bu ASAL Raprarta. paleaster, but as the disk skeleton is not preserved, it is very prob- able that when this feature is known the form will be seen to belong to a new genus.
Genus SPANIASTER Schondorf.
Plate 12, figs. 1, 2; text fig. 8. Celaster SANDBERGER (not Agassiz 1835), Verst. d. rheinischen Schicht. Nassau, 1855, p. 381. Spaniaster ScHOnvDorF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 60, 1907, p. 176; vol. 62, 1909, p. 30; Palzeontographica, vol. 56, 1909, pp. 73, 109. Remarks.—This genus with its single very small species has its nearest relations with Mesopaleaster, in that it has a single axillary interbrachial plate in each actinal axillary area, but differs from it in that there are many more adambulacral and ambulacral plates than there are inframarginals. The marked and generic difference, however, is on the abactinal side, where there are but three columns of plates, one radial and two suuramarginal, of large and thick ossicles arranged in parallel rows, the pieces of which do not alternate with ‘one another; further, the supramarginals are almost completely superposed upon the inframarginals, the two columns together, but more particularly the inframarginals, bounding the rays and not the inframarginals alone, and not so pronouncedly as in Mesopalzaster. The disk is also more primitive in its construction, in that the central 50601°—Bull. 88—15——7
96 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
disk plate is encircled by a ring of but 5 small accessory disk pieces, separating the former from the next ring of 10 much larger plates that are the primary pieces of the radial and supramarginal columns. Genoholotype and only species.—Celaster latiscutatus Sandberger. Restricted to the Lower Devonic of Germany. SPANIASTER LATISCUTATUS (Sandberger). Plate 12, figs. 1, 2; text fig. 8.
Celaster latiscutatus SANDBERGER, Verst. d. rheinischen Schicht. Nassau, 1855, p. 381, pl. 35, figs. 1, la.
Xenaster simplex Stwonovirscu, Sitz. d. mat.-naturw. Classe Akad. Wiss., Wien, vol..64. Abtcb, 1871, 39297. pl. fies. 4. da:
Spaniaster latiscutatus ScH6NDORF, Paleeontographica, vol. 56, 1909, pp. 73-82, 109, pl. 8, fig. 2; pl. 10, figs. 2,9, 10; pl. 11, fig. 9 (complete synonymy given here); Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 31, pl. 5, figs. 1-3, text fig. 2.
The Sandberger specimen, showing only the abactinal side, was found in the Lower Devonic Spiriferensandstein at Unkel, ‘near Bonn, Germany. Another specimen from the Lower Coblenzian quartzite has been recently found at Bienhorntale, near Coblenz; this shows both sides. Still another is from the Lower Coblenzian at Oberstadtfeld in the Hifel. The holotype of X. simplex is from the Upper Coblenzian at Niederlahnstein on the Rhine.
Genus MIOMASTER SchoOndorf. Plate 8, fig. 3.
Miomaster drevermanni Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 38, pl. 3, fig. 4; pl. 4, fig. 3.
Remarks.—This genus is most closely related to Spaniaster, in that both have the single axillary interbrachial plates and the infra- marginals and supramarginals are directly superposed. They differ from one another mainly on the abactinal side, though this area is so poorly preserved in Miomaster that almost nothing definite can be said. Schéndorf illustrates a section through the rays that shows the presence of single columns of very small accessory pieces between the radialia and supramarginalia. In the description, however, he states: “One can not positively determine whether the supra- marginal plates are separated from the median pieces by small accessory ossicles, or whether the three dorsal columns were closely adjoining.” The central disk area is also too much disturbed to make out the skeletal arrangement. There appear to have been small interbrachial abactinal areas. Under these circumstances, the genus Miomaster can not be said to be well established, and its final dispo- sition is dependent on finding better preserved material.
Genoholotype and only species.—M. drevermanni Schéndorf (as cited above). A single example was found by Drevermann in the Upper Coblenzian at Miellen-on-the-Lahn, Germany. The holotype is in the Senckenberg Museum, Frankfort-on-the-Main.
REVISION OF PALEOZOIC STELLEROIDEA. 97
DEVONASTER, new genus.
Plates 11 and 12. Palxaster (part) of AUTHORS. Xenaster (?) or new genus GrreGoryY, Geol. Mag., dec. 4, vol. 6, 1899, p. 346. Devonaster ScuucHeERrt, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 14.
A characteristic starfish of the American Devonic.
Generic characters—Rays five, stout, tapering rapidly. Disk large, with small interbrachial ares.
Abactinal area of rays with prominent columns of radial supra- marginals and less prominent inframarginal plates, all of which bear numerous small pustules. The radial columns are completely separated from the supramarginals by a great abundance of very small, conical, irregularly arranged, accessory plates which in the proximal region may also force apart single plates of these columns. The supramarginal columns of adjoining rays nearly meet in the axillary areas a short distance mside of the margin, at which level the radial columns also cease. Inside of the area bounded by the proximal plates of the radial and supramarginal columns, the disk has numerous small accessory plates like those of the rays. In the center of the disk is a plate somewhat more prominent than those surrounding it, and just inside of the adjoining proximal supramar- ginals is a small but distinct plate interradial in position.
Ambital accessory plates abundantly developed between the marginal ossicles in the axillary areas. These plates are like the other accessory plates and do not extend beyond the third or fourth proximal inframarginal pieces, where the ambital areas cease and the supramarginal ossicles come to lie more and more completely over the inframarginals.
Madreporite flat or concave, situated between two proximal supramarginal ossicles and outside of one of the small interradially situated plates.
Inframarginal pieces large and thick, increasing rapidly in width proximally, so that the two wedge-shaped proximal plates are nearly three times as wide as long. The plates are pustulose, and the proxi- mal ones bear several slender spines.
Adambulacral plates more numerous than the inframarginals, continuing around the axillary interbrachial plates, in front of which the columns meet in two triangular and enlarged adambu- lacral oral armature plates. Each piece bears two short, obtusely pointed spines.
Ambulacral grooves narrow and deep, either straight or very slightly petaloid. Ambulacral plates equaling in number the adambulacrals and arranged in directly opposed, closely adjoining columns. Podial openings in two columns through the sutures in the lateral part of the furrows.
98 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Axillary interbrachial plates large, a single one situated in each area between the adambulacral and inframarginal columns. Each bears short, thick, blunt spines.
Mouth plates (tori) minute, one situated in front of each pair of oral armature plates.
Genoholotype.—Paleaster eucharis Hall.
Distribution.—Restricted to the Hamilton and Chemung of the American Devonic. The species are:
D. eucharis (Hall). Hamilton. D. chemungensis, new species. Chemung.
Remarks.—This genus is readily distinguished from Hudsonaster in having well-developed radial and ambital accessory plates,. in the numerous very small plates of the disk and in the presence of interbrachial axillary plates.
Devonaster differs from Palzxaster in having radial columns of plates and in the presence of three plates in each interbrachial area against one in Paleaster. There are also other differences. From Neopalzaster it differs in having ambital accessory plates and no ocular plates; while the proximal supramarginals and radials are very large in the former, they are small in Devonaster, particularly the supramarginals, which are not readily distinguished from the accessory disk plates. In Mesopaleaster and Promopalzaster the accessory plates are always arranged in columns or rows and the ambital accessory plates are not restricted to the axillary areas as in Devonaster. Further, in those genera (excepting in the smaller forms of Mesopaleaster) there are always from two to five inter- brachial marginal plates, while Devonaster has but one axillary marginal in each interbrachial area.
Devonaster greatly resembles abactinally Xenaster of the Lower Devonic of Germany, but is readily distinguished actinally 1 in that the latter has more large interbrachial plates, and especially in the ad- dition of numerous accessory interbrachial pieces. These differences are pointed out in more detail in the remarks on Xenaster.
DEVONASTER EUCHARIS (Hall). Plate 12, figs. 3-5.
Palzaster eucharis Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 287, pl. 9, figs. 3-3a (24); rev. ed., 1868=1870, p. 330, pl. 9, figs. 3-3a (?4).— QuENsSTEDT, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 71, pl. 92, fig. 29.—Zarret, Handb. Pal., vol. 1, 1879, p. 452, fig. 323.—Coxz, Bull. Geol. Soc. America, vol. 3, 1892, p. 512, pl. 15.—Crarxe, Bull. N. Y. State Mus., No. 158, 1912, pp. 4445, 6 pls.
Xenaster eucharis ScHbNDORF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 66, 1913, pp. 87-96, pl. 3, figs. 1, 2, text figs. 1-3.
Original description.— Body rather large; the largest individual being one inch and seven-eighths from the center of the body to the extremities of the rays; the whole having a robust aspect; rays
REVISION OF PALEOZOIC STELLEROIDEA. 99
acutely pointed at the extremity. Upper [abactinal] surface of rays composed of three [radial and two supramarginal] ranges of large, highly convex or tuberculiform plates which are nearly cir- cular at the bases of the rays, becoming quadrate and widened to- wards the extremities; separated from each other in the lower part by numerous minute [accessory] plates or granules, which become fewer near the middle of the ray, and before reaching the extremity. The central portion of the disk is occupied by an elevated pentagon, the angles of which are formed by the abrupt termination of the central row of plates of each ray: the whole composed of very mi- nute, highly convex plates, which vary in size, the larger ones pen- tagonally arranged. The angles between the rays have a few [nu- merous] small [accessory ambital] plates outside of the outer ranges of tuberculose [supramarginal] plates on the upper side, uniting with the inframarginal plates below [and not extending beyond the third or fourth inframarginal proximal plate]. Madreporiform tubercle distinct, situated laterally at the bases of the outer [supra- marginal] range of large plates of two adjacent rays. Ventral sur- face having deep ambulacral grooves, bordered by two ranges of strongly tuberculose plates; the outer [infra] marginal range con- sisting of 27 or 28 plates, besides a large, round [or elliptical], ter- minal or axillary [interbrachial] plate; the others are wider than long in the basal portion of the ray, becoming gradually shorter towards the extremity where they are rounded. All the [infra] marginal plates are visible from the upper [abactinal] side, and usually appear as an additional range of plates on each margin of the ray, making five with the three properly belonging to the upper surface. Those of the inner range bordering the ambulacra (adam- bulacral plates) are smaller than the marginal plates, about 38 to 40 in number; the basal or oral plates [oral armature] are triangular, those of the adjacent rays uniting by their longer margins; and with a single minute plate situated at these points. The plates of the exterior surface, both upper and lower, present a granulose or stri- ato-granulose surface which appears to have been produced by short sete or spines; and at the angles of the rays the marginal plates are armed by a few spines, which are as long or longer than the transverse diameter of the plates. Ambulacra composed of a double range of short, broad poral plates (ossicula), equal in number to the adambulacral plates; their outer ends excavated on the posterior border, forming a comparatively large pore, just within its junction with the adambulacral plate. There appears to have heen [is] but one range of pores in each set of ossicula, but these are large, dis- tinct, and pass between [through and not between] the plates.’’ The following additional description is that of Mr. Cole. The surface of the axillary interbrachial plate ‘is granulose and bears
100 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
three short, thick, blunt pomted spines. The [infra] marginal plates bordering each reéntrant angle bear similar but more slender spines, which are not ‘as long as the transverse diameter of the plates.’ The spines are arranged.in a row near the distal margin of the plates and number five on the plates at the angle, the number and size decreasing until they disappear at the sixth or seventh plate from the angle. All the [infra] marginal plates are nearly smooth on the free margin and become gradually more granulose toward the line of junction with the adambulacral plates. * * *
“The adambulacral plates are apparently less numerous than stated in the original description, and ‘the single minute plate [mouth plates]’ at the poimts of the pairs of the oral plates [oral armature] is visible in this specimen and is armed with two relatively long, slender spines which are apparently but a part of the full armature. The adambulacral plates, including the triangular oral [armature] plates bear well-defined spines, which are shorter than the diameter of the plates to which they are attached. Each plate bears two spines so near to the distal margin that the impressions of the short and obtusely pointed spines frequently bridge the well-defined groove between the adjacent adambulacral plates and terminate near the proximal margin of the next plate. The spines decrease in size toward the end of the ray and a few plates show only one spine. The plates of this range are thick, equaling two- thirds to three-fourths the depth of the groove. The vertical angle of the faces forming the lateral walls of the groove are beveled, so that lateral extensions of the groove are formed between each two plates on the same side. These lateral expansions are narrow and shallow at the oral surface, deeper and wider inward; so that the faces of the adambulacral plates near their junction with the poral [ambulacral] plates are reduced to a narrow edge which projects inward and nearly touches the corresponding plate on the other side of the groove. The general appearance of the fossil as well as the outline of the rays at the points where the broken block presents a transverse section of them indicates that the plates have their normal position, not having suffered distortion by pressure.
‘““The ambulacral plates are shown by a well-defined mold of their under or external surface. The soft matrix which filled the ambula- cral furrow pressed upon the membranes connecting the ambulacral plates and occupying their pores, and as these membranes decayed it was forced by gentle pressure into the pores and between the edges of the plates. The mold of the groove is less than one-eighth of an inch in width in a ray measuring five-eighths at its base. The upper surface of the mold bears a narrow longitudinal median ridge which marks the junetion of the two ranges of ambulacral plates. Similar transverse ridges, which are continuous with the lines mark-
REVISION OF PALEOZOIC STELLEROIDEA. 101
ing the junction of the inner faces of the adambulacral plates, mark the proximal and distal margins of the ambulacral plates. These ridges do not cross at right angles to the median line, but include between their proximal sides an angle of about 125°. These ridges indicate that the ambulacral and adambulacral plates were equal in number, and that the former were united in pairs along a straight median line rather than in an alternate right and left arrangement along a zigzag line, as is shown in Dr. Hall’s figures. The pores described as being ‘excavated in the posterior border of the ambu- lacral plates and just within their junction with the adambulacral plates’ are not clearly shown on this specimen, although there are irregular and inconstant markings at some of the points of the molds of the lateral extensions of the groove. A series of pores near the median line is indicated by a series of small rounded prominences on each side of the median ridge and very close to it. These promi- nences are opposite the lateral expansions of the groove, and one is found on the mold of each ambulacral plate. The pores appear to have perforations very near the edges of the plates, or excavations in their margins.”’
Abnormal development.—Among the 400 specimens of this species recently found near Saugerties, New York, there are a few indi- viduals each with but four rays, though otherwise they appear to be of normal development. This is the first discovery of a four- rayed starfish in the Paleozoic.
Formation and locality —In the Hamilton of the Middle Devonic near Hamilton, Summit and Cooperstown, New York, Two sepa- rated rays of apparently this species were found by the writer in the lower third of the Hamilton near Bartletts Mills, south of Thedford, Ontario. Two other fragments from the same locality are in the University of Toronto (Walker collection, No. 1610H). The type and other specimens are in the American Museum of Natural History, one is in Colgate University, another at Wesleyan University, and two in Yale University Museum.
Recently the New York State Survey collected in the Hamilton sandstone at Mount Marion, near Saugerties, New York, over 400 examples of this fine starfish. They occur in a limited area and are often found in association with Grammysia and in such manner that Doctor Clarke believes the starfishes were feeding on the bivalves. This is probably the most remarkable find of Paleozoic starfishes, and is certainly so for America.
DEVONASTER CHEMUNGENSIS, new species.
Plate 11, fig. 2.
Of this species only the actinal side is known, and its general structure so far as can be made out is that of D. eucharis (Hall).
102 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
It differs from the latter in that each axillary interbrachial plate bears one stout spine, while D. eucharis has three. Further, in D. eucharis six or seven of the proximal inframarginal plates of each column bear on their outer side a number of: small, slender spines. In D. chemungensis these spines may also be present but in addition each plate bears centrally a prominent tubercle for the articulation of a large spine.
Formation and locality —The type is in the Museum of Columbia University, New York City (No. 6228G). It is from the Spirifer disjunctus sandstone of the Chemung of ‘‘Central Pennsylvania.”’
NEW GENUS. NEW SPECIES.
In the University of Chicago collection there is a specimen (No. 14397) collected by Professor Weller in the St. Louis limestone on Fountain Creek, at Waterloo, Llinois. This five-rayed asterid is small, shows only the abactinal side, and has very long but narrow marginals and not over six or possibly seven in a column; the basal plates of adjoining columns make the axils. Otherwise the abactinal skeleton of the rays consists of many small, loosely adjoining pieces whose arrangement can not be made out. Nor can the disk struc- ture be determined.
The relationship of this specimen seems to be with the Promo- - palzasteride, with possible nearest affinity to the genus Mesopa- leaster.
Measurements: R=not less than 10 mm., r=4 mm.
PROMOPALHASTHRIN 4D, new subfamily.
Progressive Promopaleasteride with the interbrachial areas com- plex and composed of the single axillary interbrachials, more than one pair of interbrachial marginals, and adambulacral plates. Podial openings in each ambulacral furrow mainly in two columns, but proximally there may be two additional ones in a length never more than one-third the rays.
Contains:
Promopalzaster, new genus.
PROMOPALZASTER, new genus.
Plates 13 to 23, 25. Palzaster (part) of AuTHoRs. Promopalxaster Scuucuert, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 24. Promos, chief, and aster. The largest and chief starfishes of the American Ordovic. Generic characters—Disk above medium size, with distinct and angular interbrachial arcs. Rays five, slender to stout, more or less long, and tapering. Some species attain a large growth.
REVISION OF PALEOZOIC STELLEROIDEA. 1038
Abactinal area of rays with numerous columns of small, more or less tumid, closely adjoining or reticulated, spine-bearing plates. <A medial radial and two lateral or supramarginal columns of plates are usually more conspicuous than the accessory columns; however, the radial plates may be also inconspicuous. The longitudinal arrange- ment in columns is usually most pronounced, but sometimes the plates on each side of the radial column may have a decided diagonal arrangement. Small accessory plates are usually inserted between the columns of ossicles or between the individual pieces both distally and proximally. Disk with numerous small accessory plates like those of the rays, with no apparent definite arrangement except the supramarginal columns, which continue over the disk and unite angularly in the axillary areas. The larger plates bear several short articulating spines of which the one on the apex is the largest.
Ambital areas well developed, there being one or more columns of small plates like the radial accessory columns both in form and arrangement.
Madreporite usually conspicuous, radially striated, and situated near the margin of the disk between the adjoining columns of supra- marginal plates.
Inframarginal plates small and numerous distally like the adambu- lacrals, but proximally they usually increase rapidly in width and assist in forming the small interbrachial arcs. Each ossicle has numerous small granules which probably bore short, smooth, articu- lating, blunt spines.
Adambulacral plates distally like the inframarginals, increasing in width proximally and continuing around the plates of the inter- brachial areas. The two proximal plates of adjoining columns are the pairs of plates in the oral armature. Each adambulacral plate has a more or less well-developed narrow ambulacral extension which unites with the carina of the ambulacral plates. These extensions belong to the adambulacral plates, apparently always so distally, but proximally they are often separated from the adambulacral plates by sutures; throughout the greater portion of the rays they are situ- ated medially, but in the proximal region they are either on the distal or proximal edge, each alternate plate having the extension from the same corner a little longer. Each plate has more or less numerous spine-bearing granules in addition to the three larger articulating spines which are inserted one on the ambulacral and two on the lateral edge.
Ambulacral furrows generally very wide and regularly tapering. In each ray there are two columns of these plates which are slightly alternating or opposite. The plates are as numerous as those of the adambulacral columns, highly carinated, about as wide as long in the extreme distal portion of a ray, increasing rapidly in width proximally
104 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
and at the base of the rays may be four times as wide as long. The podial openings, one to each plate and in single ranges, are at the extreme lateral edges excavated between the sutures of adjoining plates and beneath the adambulacrals. Proximally, however, every other podial opening progresses inwardly with the joined carine and issues where these begin to fork. Here there are, therefore, four columns of podial openings in each ambulacral furrow. This change is indicated by the changed position of the adambulacral plate exten- sions and also by the pairs of forked carine of the ambulacral plates. Throughout the greater portion of a ray the care are regular and alike on each plate, but toward the mouth they change rapidly in direction and soon they are arranged in forked pairs, one curving distally, the other proximally, with the lateral portions of each pair in contact and uniting with the extensions of the adambulacral plates. The most proximal plate of each ambulacral column is usually considerably modified, longer than wide, and more or less triangular in outline, between which there is sometimes inserted a small quadrangular ossicle. These pieces belong to the oral armature.
Interbrachial areas of medium size, with the interbrachial marginal plates usually arranged in pairs but in some forms the series may be terminated by single ossicles. The number of these plates in an area varies in different species, there being two, three, or five inside the marginal inframarginals, and all seem to be derived from the inframarginal series by inward crowding.
Genoholotype.—Palzaster granulosus Meek (not Hall=P. speciosus Meek).
Distribution.—Restricted to the Middle and Upper Ordovicie cf America, chiefly within a radius of 50 miles about Cincinnati, Ohio. The following are the known species:
. wilsont (Raymond). Black River (Lowville).
. prenuntius, new species. Trenton.
sp. undet. Young of P. speciosus Meek. Maysvillian. . speciosus (Meek). Maysvillan.
granulosus (Hall). Lower Richmond.
bellulus, new species. Richmond.
. spynulosus (Miller and Dyer). Richmond.
. exculptus (Miller). Richmond.
. wykofft (Miller and Gurley). Richmond.
. dyert (Meek). Maysvillian.
. magnificus (Miller). Maysvillian and Richmond.
Remarks.—Kight of the ten species here referred to Promopalzaster have been described as Palxasier. They have little direct relationship with the latter genus in that the species are much larger, have well developed ambital areas, numerous accessory plates, well defined
riots ty
REVISION OF PALEOZOIC STELLEROIDEA. 105
interbrachial ares, and from two to five interbrachial marginal plates in each interbrachial area. Promopalzaster is a direct development from Mesopalxaster, in that it preserves the generic characters of the latter, which is in turn a descendant of Hudsonaster. In Hudsonaster there are no interbrachial plates, accessory or ambital columns. In Mesopalxaster the single axillary marginal plate of Hudsonaster has been crowded orally and is no longer a marginal but an axillary interbrachial. Further, the radial and both marginal columns are more or less completely separated from one another by accessory columns of smaller plates. In Promopalxaster this addition of columns of small plates is carried to its greatest development. The character, however, which is relied upon to distinguish it from Meso- paleaster is that Promopalxaster always has two or more interbrachial marginal plates in each interbrachial area, while the former genus has one, the axillary interbrachial, and Puaconacke yr has none. The position and number of axillary and interbrachial marginal plates will readily distinguish these genera, but if the abactinal area of a new form alone is seen it will be difficult to determine whether it is a Mesopaleaster or Promopaleaster. Small size and few accessory columns, especially ambital, will help somewhat to distinguish Mesopalexaster from Promopalxaster.
Accepting Promopaleaster as a descendant of Mesopalxasier, it is seen that the axillary interbrachial plates of the latter have in P. exculptus been followed by two proximal pieces of adjoining infra- marginal columns. The same is probably true of P. spinulosus, but here no axillary interbrachial has been observed. In P. speciosus and P. bellulus, another pair of proximal inframarginals have become interbrachial plates, but the axillary interbrachial is also unknown in this species. In P. dyer and P. magnificus the axillary inter- brachial is present along with two pairs of interbrachial marginals. In other words, there is in Promopalzaster a constant increase in the size of the interbrachial area produced by the crowding of pairs of proximal inframarginal plates.
P. speciosus and P. bellulus are closely related species, and so far as can be determined have but two interbrachial marginal plates, while our theoretic development requires three. There is, however, in each area orad to the interbrachial plates a small hiatus which in some cases appears to be filled by extensions from the adambulacral plates. It seems therefore probable that the axillary interbrachial plate may be retained, but is not now discernible on account of its small size or adhering clay; it may also have dropped out or have been absorbed and its place occupied by the adjoining adambulacral plates.
In a general way it can be stated that there is also a regular increase in the number of accessory plates from Mesopalxaster to Promopale- aster through P. spinulosus, P. speciosus, P. bellulus, P. dyeri into
106 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
P. magnificus. It seems probable from the mature material studied that the most differentiated species of Promopalzaster, P. magnificus, passed through ontogenetic stages comparable to Hudsonaster, Meso- paleaster granti, and Promopalzaster bellulus.
P. magnificus at present stands alone in its beautiful diagonal and longitudinal arrangement of abactinal plates.
PROMOPALZASTER WILSONI (Raymond). Plate 13, figs. 1, 2.
Palzaster? wilsoni RayMonpD, Ottawa Naturalist, vol. 26, 1912, p. 77, pl. 5, figs. 1-4.
Original description.—“ The specimen is exposed from the abactinal side, and preserves the greater part of one arm, the disk, and the stumps of the other four arms. The diameter of the specimen, when complete, must have been about 75 mm. (3 inches), and the diameter of the disk is 20 mm. This is large for a starfish from the lower Ordovician. The arms are quite convex, with a gentle taper, reminding one somewhat of the common recent starfish, Asterias vulgaris, and as in that species, the arms were probably somewhat flexible. The greater part of the abactinal side of the disk and arms is covered with small convex, overlapping, V-shaped plates, which are arranged with the point of the V directed toward the margins. Along the crest of each arm there is a single row of larger plates (radial column). These plates are quite large.and hexagonal in out- line near the disk, but become smaller, triangular, and alternate in position farther out on the arm. There are two rows of marginals [supra and infra] these plates being larger and flatter than the other plates, and covered with minute tubercles, which may be spine bases. Close to the disk, the supramarginals and [infra] marginals seem to be of the same size, both rectangular, and the plates of the supra- marginal row directly over those of the marginal series. Farther out on the arms, the plates are pentagonal, those of the two rows alternating in position, and dove-tailing, and the supramarginals are smaller than the marginals. One of the marginals, about half- way out on the arm, is 1.25 mm. high and of about the same breadth. The smaller triangular plates which cover the greater part of the arm average about 0.5 to 0.6 mm. in height. On one of the arms, the small triangular plates seem to be arranged in rows parallel to the axis of the arm, but the plates on the longer arm seem to be more irregular, although a general arrangement in rows can be seen. On this arm there are a number of very small plates scattered about, especially on the top of the arm, thus adding to the irregularity. The triangular shape of these plates gives the arm a neat pattern, the plates making diagonal rows backward and forward from the row of large plates along the top of the arm. The madreporite, which is nearly circular in outline, and 2 mm. in diameter, is in position, but slightly
REVISION OF PALEOZOIC STELLEROIDEA. Loy
tipped down at the inner side, in an interradius, and not far from the center of the abactinal side of the disk. Thesurface is probably worn, for it appears perfectly smooth.”
In places the abactinal ossicles are removed, “disclosing the ambu- lacral plates. These plates, which are long and rather thick, seem to be alternate in position. Two of the plates seem to be pierced by pores near their proximate ends, two pores piercing each plate ver- tically. Near the outer end of the more perfect arm there is a space where a few of the small triangular plates are missing, and here also the ambulacral plates can be seen from the upper side. Each plate has a narrow keel on that side. Other details of the plates of the actinal side are unknown.”
Formation and locality—In the Lowville limestone at City View, near Ottawa, Canada, where this interesting asterid was found by Miss A. E. Wilson, in whose collection the holotype now is.
Remarks.—It. is interesting to note that this fully developed Promopalxaster, one closely related to P. magnificus of the highest Ordovicic, occurs in much older rocks; that is, in the Black River formation. This occurrence again brings out the fact often noted by the writer, that Paleozoic asterids are slow to change in characters accessible to the paleontologist.
P. magniticus, like P. wilsoni, Raymond states, “has two rows of large marginals and a row of large plates along the top of each arm, while the greater part of the surface is covered with small convex triangular plates. Miller found the plates to be spine-bearing, a point which can not be definitely decided in the present species. From the photograph (submitted by Schuchert) it appears that there are spaces between the small triangular plates on the abactinal sur- face in Palzaster ? magnificus, while in P. ? wilsoni these plates actually overlap each other.”
PROMOPALZASTER PRENUNTIUS, new species. Plate 13, fig. 3; plate 15, fig. 5.
Remarks.—This species is represented by a good specimen showing the actinal side, the other adhering to the limestone. R—=somewhat less than 30 mm., r=7 mm. Width of ray at base about 9 mm.
P. prenuntius is closely related to P. speciosus, but is distinguished therefrom by the smaller size, less pustulose ornamentation of the plates, and the lower position in the geological column. The plates of the axial area are also more regular in size and there are in the proximal region nearly always two adambulacrals to each inframar- ginal; at about mid-length of the rays the plates of each of the two columns are about equal in number, but every now and then there is some duplication among the adambulacrals. P. prenuntius is equally as spinose as P. speciosus and the former is undoubtedly the ancestor of the latter.
108 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Formation and locality.—The holotype was collected by Mr. Wendt near Frankfort, Kentucky, apparently in the Lower Trenton. The writer’s attention was called to it by Prof. Arthur M. Miller, who has it in his charge at the State University of Kentucky at Lexington.
PROMOPALZASTER, species undetermined. Plate 14, figs. 1, 2.
Asterias primordialis ANONYMOUS, two lithographic figures sent out by the Western Academy of Sciences previous to 1872 without description or known author. Nothing more is known of this species than the two good original illustrations reproduced here. These figures were sent to F. B. Meek on May 18, 1872, by Mr. D. H. Shaffer, of Cincinnati, Ohio, with the following comment (they were found in the Meek correspondence kept in the United States National Museum): “The lithograph in- closed of this Asterias was found here, and in the possession of Joseph Clark (deceased). I saw it, and this is a faithful picture of it. I think the fossil is either in the possession of his nephew or in the cabinet of Maxwell’s Female Seminary, which now is the owner of Mr. Clark’s cabinet. I think it is worthy a place with Palzaster shafferi in the illustrations of the Ohio Geological Survey.”
From the illustration one sees that this form had on the abactinal side of the rays about nine columns of ossicles. Of these the radial, supra- and inframarginals are largest. Between the marginals there is a single column of tiny ambital pieces, while on each side of the radials are two columns of small accessory pieces. The structure of the disk pieces can not be made out.
The interbrachial areas are small and do not appear to have more than two inwardly crowded inframarginals, but there may also be present single very small axillary pieces.
The adambulacral and inframarginal columns appear to have not more than 20 ossicles in a column. Of ambulacrals there are some- what more, about 25, and these alternate slightly with one another.
“ Asterias primordialis” appears to be the young of Promopale- aster speciosus (Meek), and the differences can all be explained as due to incomplete development; that is, the former has fewer ossicles and fewer secondary columns of plates.
Formation and locality —From the hills of Cincinnati, in the Mays- ville formation. The present whereabouts of this fine specimen is unknown. A still smaller and younger specimen is in the Faber collection of the University of Chicago (No. 9567), and was collected at 350 feet above the Ohio River at Cincinnati. It has but a single axillary plate in each interbrachial area, and about 15 adambulacrals in a column. It is interesting to note that in these young individuals of Promopaleaster, the smaller they are the more they approach Mesopalxaster and suggest Hudsonaster.
REVISION OF PALEOZOIC STELLEROIDEA. 109
PROMOPALZASTER SPECIOSUS (Meek). Plate 14, figs. 3, 4; plate 15, figs. 1-4.
Asterias antiquata Locke (not A. antiqua Troost), Proc. Acad. Nat. Sci., Phila- delphia, for 1846-47, vol. 3, 1848, p. 32, fig. on p. 33.
Palxaster antiquata Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 286.
Palzxaster antiquatus Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., rev. ed., 1868=1870, p. 328.
Palxaster granulosus Mrrx (not Hall 1868), Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 276; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 60, pl. 4, figs. 3a-c.
Palzaster speciosus Merx, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 277 (name at end of description); Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 61 (name at end of description).
Also see Promopalzxaster, sp. undet., page 108.
Original description by Meek (1873).—‘‘ Attaining a large size; rays (as a little depressed by accident) slightly more than twice as long as their breadth at their inner ends; and tapering regularly from the disk to their free ends, which are rather acutely angular; breadth of the disk a little less than that of the inner ends of the rays. Mar- ginal pieces convex [bearing numerous small spines], nearly or quite as long as wide, numbering on each side, in the whole length of each ray (1.40 inch), 31. Adambulacral pieces, a size smaller, as long as wide, convex, and numbering on each side 39 to 40; like those of the [infra] marginal series, each bearing a small spine [several spines], the largest of which are each about 0.14 inch in length and 0.02 inch in thickness [between each two adambulacral plates just above the podial opening is inserted a large and thick spine]. Ambulacral pieces very short, or nearly three times as wide as long, apparently not alternating with the adambulacral pieces, and each provided with a rather sharp ridge across nearly its entire breadth. Dorsal side of disk and rays composed of small tuberculiform pieces, of which about 16 rows may be counted at about half way between the inner and outer ends of each ray, along the middle of which those of two [always two] or three of the rows are a little larger than the others; each dorsal piece bearing a minute, very short spine [they are nume- rous and like those of the marginal plates]. Surface of all the pieces minutely granular, one of the central granules always being somewhat larger than the others for the articulation of a spine [all of these granules bear spines]. Oral pieces and madreporiform body un- known.”
Emended description—Rays regularly tapering. R=44 mm., r=11mm., R=4r. Width of ray at base 14 mm.
Abactinal area of rays covered by small, highly convex, tuber- culated plates, each bearing numerous short slender spines. These ossicles are arranged in longitudinal columns, of which there are 15 on each ray at about its mid-length. The plates of one or
110 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
two median columns are larger and more convex than the three columns immediately on each side, while the pieces of the fourth column are again more pronounced than those on each side of it, and probably represent the supramarginals. Between the supramarginals and the inframarginals are from one to three columns of ambital plates, and between these are inserted here and there some small extra pieces. The extra pieces are mainly developed beside the supra- marginal columns. Plates of the disk like those of the rays, but their arrangement is unknown.
Madreporite unknown.
Inframarginal plates very convex, about as wide as long except- ing near the base of the columns where they are about twice as wide as long. There are about 31 of these ossicles in a column, and they have numerous small, slender, sharp spines articulating on well- developed tubercles.
Adambulacral plates greatly resembling the inframarginals. They are largest near the mid-length of each ray, diminish in size distally, but proximally they hold their width and decrease in length and therefore are more numerous. There are 43 plates in each column besides those in the oral armature. Ambulacrally each adambulacral plate has a short attenuate extension which articulates with the crests of the ambulacral plates. Between all the adam- bulacral ossicles there is inserted in the suture facing the ambulacral eroove a single large, thick spine, excepting for a short distance proximally where such are inserted in every other suture. The lateral surface of the adambulacral plates in the distal half of the columns bears numerous small spines like those of the inframarginal series, but proximally these spines are gradually displaced by two or possibly more larger ones like those on the ambulacral face.
Ambulacral furrows wide and deep. Ambulacral plates of adjoin- ing columns opposite, two or three times as wide as long, and slightly overlapping proximally. Upon each plate there is a high median ridge which arises at the inner end of the plate and abuts against the short extension of the adambulacral plate. The podial open- ings are between the plates and beneath the sutures of the adam- bulacral plates, excepting near the base of the rays, where they occur in every other suture. The ridges here are sigmoid and not straight, as they are more distally. There appear never to be more than two rows of podia in an ambulacrum. »
In each axillary area inside of two large inframarginal plates and between the converging adambulacral columns are inserted two pairs of wedge-shaped interbrachial marginal plates ornamented like the inframarginals.
Formation and locality —The holotype and only known specimen was-collected by Mr. Charles B. Dyer in the Maysvillian at Cin-
REVISION OF PALEOZOIC STELLEROIDEA. 1 ta
cinnati, Ohio. It is now in the Dyer collection, Museum of Com- parative Zoédlogy (No. 22), Harvard University. The original of Asterias antiquata Locke was found at Cincinnati, but the specimen appears to be lost.
Remarks.—Meck (1873) in describing this specimen, provisionally referred it to Palxaster granulosus Hall and commented as follows:
“Although this fine Star-fish agrees pretty well in most of its characters with the description of Palzaster granulosus of Hall (which has not yet been figured), I am far from being entirely satisfied that it is really the same, as it seems to differ in some important respects. For instance, the rays of P. granulosus are described as being ‘cbtusely rounded at the extremities’; while in the form under consideration they are rather acutely rounded, if not angular. Again, instead of having 25 of the marginal pieces on each side, in a space of one inch and a quarter from the apex of each ray, and 42 or 43 of the adam- bulacral, it shows in this space 28 marginal and only 32 adambula- cral pieces. The number of the latter being about 10 less on each side in the same space—a rather decided difference, showing the inner row to consist of proportionally larger pieces. Its ambulacral ossicula seem to have the same proportional breadth and length as in the type of P. granulosus and also have each a similar ridge across the middle; but these ridges do not show the zigzag arrangement mentioned in the description of P. granulosus. Prof. Hall does not say how many rows of pieces are seen on the dorsal sides of the rays of his species; but he states that it is probably the same species that the Western Academy of Sciences sent out lithographs of under the name Asterias primordialis. One of these lithographs, now before me [reproduced here on plate 14, figs. 1, 2], represents from 8 to 10 rows of these dorsal pieces, which is 6 or 8 less than may be counted near the middle of the rays of our specimen.
“Tn noticing this form in the Am. Jour. Sci., vol. 3 (3d series), p. 277, I proposed, in case it should be distinct from P. granulosus, to call it P. speciosus.”
With such marked differences between P. granulosus and P. speci- osus, and since the type-specimen of the former can not be located to determine the interbrachial structure, it is deemed advisable to adopt Meek’s name P. speciosus for the specimen described above.
In the upper portion of the Ordovicic in the Richmond formation occurs another closely related species, P. bellulus, which is dis- tinguished from P. speciosus in having more slender rays and usually a greater number of plates in the actinal columns. The greatest difference, however, is that it has seven pairs of adjoining adam- bulacral plates proximal to the interbrachial plates, while in P. speciosus there are but two or three pairs of adambulacrals. In other words, the adambulacral oral extensions are far longer in P. bellulus than in P. speciosus.
50601°—Bull. 88—15——-8
112 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
The illustration of Asterias antiquata Locke referred to above by Meek is very poor, and yet it seems to be the same species which the latter described as P. granulosus Hall=P. speciosus Meek. This, however, can not now be established since the whereabouts of Locke’s specimen is unknown. Both specimens are from Cin- cinnati and are of about the same size. Hall comments on this species (1870) as follows:
“This species was noticed by Dr. Locke, as cited above, but with- out specific description, and expressing a doubt whether it was or was not identical with the Asterias antiqua of Troost. The figure would indicate a distinct species from that of Dr. Troost.”
PROMOPALZASTER GRANULOSUS (Hall). Palzaster granulosa Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 285. Palzaster granulosus Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., rev. ed., 1868=1870, p. 327.
Original description.—‘‘Body of medium size, five rayed; rays a little more than twice as long as their breadth at base; obtusely rounded at the extremities. Upper surface of rays composed of numerous very small tuberculose or subspinose plates; the madre- poric tubercle large, quite distinct, situated laterally at the base of two of the rays. Under surface of rays composed of a [infra]marginal range of small tuberculose plates, about 25 on each side in a ray measuring one inch and a quarter from base to apex; and an inner (adambulacral) range of smaller plates, of which about 42 or 43 can be counted on the same ray; the terminal or oral [armature] plates are small, elongate, subtriangular, in pairs at the base of the adjacent rays. Ambulacral areas composed of a double series of short, broad, slightly curved poral plates (ossicula), each plate marked by a sharply » elevated ridge along its entire breadth, commencing on the one plate at the outer posterior angle and terminating on the anterior inner angle, and running in the opposite direction on the adjacent plate. When the outer ridged surface of the poral plate is ground away, the narrow openings or pores are visible between the plates, apparently in two rows in each series, making four ranges of pores in each ambu- lacral area. (The marginal ranges of pores are obscure, and may only be apparent [there is probably an error here in regarding the inner openings as podial openings].) On the under surface, near the bases of the rays, the tubercles bear short spines some of which are still in place.”
“Some figures of a Palzaster, closely allied to or identical with this one, from Cincinnati, Ohio, have been circulated by the Natural History Society of that place, under the name of Asterias primordialis; but no description of it has ever been published, so far as I know, nor
REVISION OF PALEOZOIC STELLEROIDEA. its
do I find it at all recognized in the catalogues.” These original figures are here reproduced as Promopalxasier, sp. undet. (pl. 14, figs. 1, 2). The specimen is probabiy an immature individual of P. speciosus.
Formation and locality —The holotype was found by Mr. J. Kelly O’Neall in the Lower Richmond formation near Lebanon, Ohio, and was loaned to Hall for description. The whereabouts of the specimen can not now be located. Some years ago the writer asked the late Professor Whitfield about it and he answered that Hall had returned it to O’Neall, but the latter in turn wrote (Aug. 27, 1896) that he had not received it.
Remarks.—This species seems to be distinguished by the smaller number of plates in the inframarginal columns, as the following table shows. However, until the nature of the interbrachial areas is known, the relationship of P. granulosus to other Paleozoic forms can not be stated.
Seal Inframar- | Adambu- | _ Inter- lacrals ginals. lacrals. | brachials, | 0F@d to inter-
| brachials.
| P. granulosus (Hall)............-.----- eee mteeeisiee a> <1 25 42-49 | Soe eee ele boos PEBES PCCIOSIES: (MICO) ocr cee a asin «eave cae ne saed ANee ee si 31 43 4 4 IP UCUUIUS, NOW SPOCIOS- —22 5-52 6-0 Secsolseentese= oon Ss 31-38 48-55 4 8 PPA MUEG TICES (MAU OL) ooo amo kao kcdccwseidecosemecect aes 45 50-52 5 5-6
\ !
PROMOPALASASTER BELLULUS, new species. Plate 15, figs. 6-8; plate 16, fig. 1; plate 18, figs. 4, 5.
R=36 mm.,r=10mm., R=3.6r. Width of ray at base, 11.5 mm.
A first view of this species gives the impression of P. speciosus (Meek). Of the latter but a single specimen is known and it is now lost, while of P. bellulus there are numerous examples, all of which have the same specific characters. The specimens preserved in lime- stone have the rays more slender, while those from soft shale are as stout as in P. speciosus.
In the holotype of P. bellulus from limestone there are 55 adam- bulacral and 38 inframarginal plates in each column, while in P. speciosus there are 43 and 31 plates, respectively, in the same columns. Shale specimens of P. bellulus have less plates in a column. One of these, a somewhat smaller specimen than the holotype, has 31 inframarginal plates, the same number as in P. speciosus, and about 48 adambulacrals in each column. P. bellulus has therefore from 31 to 38 inframarginal plates and from 48 to 55 adambulacral plates in each column.
114 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
A more important distinguishing character exists in the inter- brachial areas. In P. bellulus and P. speciosus there are two pairs or four interbrachial marginal plates, while the number of adjoining adambulacral plates is greater. In the latter there are four of these on each side, while in the former there are eight. In other words, the interbrachial areas in P. bellulus are much more elongated orally than in P. speciosus and the interbrachial arcs are also greater.
Abactinally on the rays the arrangement and number of columns of plates appear to be very much like those in P. speciosus. The individual plates are, however, less convex, cruciform, more like those of P. spinulosus, and have stronger and more abundant spines. The spines in P. bellulus are very numerous, short, and slender, and are inserted one on the apex of each plate and a number around the sides in the angles between the radial extensions. In P. speciosus the spines are grouped over the convex area of the plate and around the larger central spine. The arrangement of the plates of the disk appears to have no marked pattern and consists of very numerous small plates like those of the rays.
The adambulacral plates each bear three spines as in P. speciosus and increase in size toward the base of the rays. One is inserted on the inner or ambulacral face of the plate and the two closely adjoining ones immediately above and laterally on the rounded surface.
Ambulacral plates as in P. speciosus.
Madreporite of medium size, subcircular in outline, with numerous straight, sharp, radiating ridges. It is inserted proximally between two adjoining columns of supramarginal plates.
A development occurring only in this species of Promopalzaster is a single plate oral to the proximal adambulacrals. This plate has been seen in four axillary areas. It may be a modified ambu- lacral and may correspond to a similar plate, which is an ambulacral, in P. exculptus.
Formation and locality —Of this species quite a number of speci- mens were secured by Mr. Harris in the Waynesville beds of the Richmondian. They are all in the United States National Museum. One excellent specimen (the holotype) showing the actinal area, and two smaller poorer specimens are attached to limestone, while eleven fair specimens and fragments of eight other individuals are from a soft blue shale associated with Zygospira modesta and Ptilo- dictya shaffert (upper form). All were secured in the vicinity of Waynesville, Ohio. The shale specimens were exhumed from one small area, showing that probably many starfishes could be similarly secured by collectors, since these soft specimens in weathering out are broken up and lost; more asterids will be found when they are dug or quarried for. Another good specimen is in the Gurley col- lection of the University of Chicago (No. 10983) and was found at Versailles, Indiana.
REVISION OF PALEOZOIC STELLEROIDEA. 115
Remarks.—The similarity and difference between P. bellulus and P. speciosus are pointed out above. Another related species is P. spinu- losus, which has the same kind of abactinal plates and madreporite as P. bellulus. In the former the rays are far longer and narrower, with fewer ambital plates and columns between the supramarginals. Actinally P. spinulosus is at once distinguished from P. bellulus in the much smaller interbrachial areas, in that it does not have more than two interbrachial marginal plates while P. bellulus has four. In the latter species there are also far more adambulacral plates around the interbrachial pieces.
It will always be difficult to distinguish fragments of P. bellulus, P. speciosus, and P. spinulosus from one another, even with good material, since at least two specimens of P. bcllulus were identified as Palxaster granulosus Hall=Promopalxaster speciosus (Meek).
Cat. No. 40879, U.S.N.M.
PROMOPALZASTER SPINULOSUS (Miller and Dyer). Plate 16, fig. 2; plate 17, figs. 1, 2; plate 18, figs. 1-3.
Compare with Promopalzaster exculptus (Miller).
Palxaster spinulosus Miter and Dyer, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 32, pl. 2, figs. 12-120.
Palxaster longibrachiatus Miter, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 102, pl. 3, fig. 4.
Original description (of Palexaster spinulosus).—‘ Pentagonal; rays longer than the diameter of the body; marginal plates globular near the apices of the rays, but lengthened toward the junction with the body. Six of these plates measure from the body on a ray three-tenths of an inch. Two wedge-shaped plates form the junc- tion of the marginal plates with the body.
‘‘Adambulacral plates a little smaller [in width] than the margi- nal pieces, and possessed of two or three [four or more] spines to each plate. These spines taper to a fine point, and are longer than the diameter of the plates. The oral pieces are not determined [they are like those in P. exculptus]._ The ambulacral plates have their greatest length across the rays, and are possessed of a sharp ridge in the middle which seems to be [is] connected at one end with the adambulacral pieces. [The entire number of plates in each range can not be given, since the rays are imperfect.].
‘The dorsal side is covered with plates united by angular exten- sions. They are of unequal size, and strongly tuberculated or spi- nous.
“The madreporiform tubercle on its upper face is an oblate sphe- roid, much depressed, and marked by fine radiating strie, which become more numerous by intercalation, without bifurcation. [This plate is interpolated between the proximal plates of two ad-
116 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
joining columns of supramarginal ossicles and about medially be- tween the margin and the center of the disk.]”’
Supplementary description—R unknown, r=7 mm. Width of ray at base 9 mm.
Abactinal area of rays margmed by inframarginals, above and inside of which are columns of large, bipyriform, multispinous, su- pramarginal plates of which there are five in 5 mm. at the base of a ray. The columns of adjoining rays unite in the axillary areas. Inside of the supramarginal columns the rays and disk have numer- ous smaller accessory plates, usually triangular in outline or vari- ously stellate. They lie upon or against each other, each ossicle bearing at least one small spine, and leave between them numerous abactinal openings. Outside of the supramarginal plates in the ambital areas are spicular ambital plates which cover the abactinal side of the inframarginals.
Description of the type of Paleaster longibrachiatus.—R =38 mm., r=7mm., R=5.4r. Width of ray at base 9 mm.
Rays large, slender, tapering slowly; actinally somewhat convex at their outer ends, but elsewhere concave.
Abactinal area unknown.
Inframarginal plates granular, large, decreasing gradually in size distally, highly convex, in outline tetragonal or pentagonal and common to both the abactinal and actinal areas. From 28 to 30 plates in a column on each side of a ray.
Axillary areas occupied by the proximal plates of adjoining infra- marginal columns, and in the interbrachial areas there are two sub- quadrangular or subtriangular interbrachial marginal plates. There may be an additional small single plate in each area.
Adambulacral plates greatly resembling the inframarginal ossicles. Distally they progressively overlap the inframarginal plates con- siderably, while proximally they gradually increase in size and are entirely inside and depressed beneath the plane of the marginal columns. Orally the columns of adjoining rays unite in two wees shaped modified adambulacrals (oral armature pieces).
Ambulacral furrows deep and gradually tapering. Ambulacral plates unknown.
Formation and locality—The type of Palzaster spinulosus (No. 16, Mus. Comp. Zo6l.) is said to have been found at Cincinnati, Ohio. This is probably an error, since its color and preservation indicate the Richmond formation and that it comes from some locality considerably to the north of Cincinnati. The only other known specimen, the type of P. longibrachiatus, was found in the Richmond formation near Clarksville, Ohio, and is in the Harris collection, United States National Museum.
Remarks.—The type-specimen of Palzxaster spinulosus, which is free, preserves but the disk and a small proximal portion of the rays.
REVISION OF PALEOZOIC STELLEROIDEA. Ez
Comparing it with the actinal area of P. longibrachiatus Miller, it is evident that both forms are identical. In the latter the rays are complete, very long and slender, and there is nothing to show that they were dissimilar in P. spinulosus Miller and Dyer. Both types are nearly of the same size and the actinal plates are identical in form and arrangement. The abactinal area in P. longibrachiatus is not known, but since its actinal structure is that of Promopaleaster spinulosus it is safe to assume that the abactinal structure is alike in both.
P. spinulosus actinally is also closely related to P. exculptus (Miller). The latter appears to have shorter and more rapidly tapering rays and in general seems to be a more robust species. Another character by which these species can be separated is that the interbrachial areas in P. spinulosus have two, while P. exculptus has three inter- brachial marginal plates. It is possible that the former species also has three interbrachial marginal plates, but as yet the small single piece of each area has not been observed, while in P. exculptus it is distinctly present in each of the five areas. Should P. spin- ulosus also prove to have three interbrachial plates, it would be diffi- cult to distinguish it actinally from P. exculptus.
P. dyert and P. magnificus are far larger species and have five interbrachial marginal plates in each area.
Cat. No. 40881, U.S.N.M.
PROMOPALZASTER EXCULPTUS (Miller). Plate 18, fig. 7; plate 20, fig. 2.
Compare with Promopalzxaster spinulosus (Miller and Dyer). Palzaster exculptus MuiErR, Journ, Cincinnati Soc. Nat. Hist., vol. 4, 1881, p. 69, plod fest.
Original description.—‘Pentagonal; rays a little longer than the diameter of the body; diameter of the body, about 0.93 inch; length of ray measuring to the center of the body or disk, about 14 inches; breadth of a ray at the junction with the body, about 0.57 inch; rays obtusely pointed.
‘“The [infra-] marginal range consists of somewhat quadrangular plates, having a width a little greater than the length; the first 8 of these have a length of one-half inch, and there are about 18 in the length of an inch, and not far from 25 in each range, though the specimen does not permit us to make the count with certainty. The surface is strongly tubercular, and was probably spinous [originally covered with numerous small spines].
‘‘The adambulacral range consists of about 28 [25] plates, on each side of a ray; they are narrower than the marginal plates, but have about the same length. Each plate [has a short ambulacral exten- sion conforming with the ridge of the ambulacral plates and] bore
118 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
strong spines, and some of them, preserved on our specimen, have a length greater than the length of a plate. * * *
‘‘The ambulacral plates have their greatest length across the rays, thus providing a wide ambulacral furrow. Lach plate is furnished with a sharp ridge in the middle, that curves slightly outward, from the center toward the adambulacral range, increasing in height until it approaches or abuts against the adambulacral plate. * * * The appearance of having been carved out, which is presented by the ambulacral plates, suggested the specific name. [The plates of adjoining columns are opposite one another or slightly alternate.]
‘‘The dorsal side and madreporiform tubercle unknown.”’
Supplementary description —R=37 mm., r=12 mm., R=3.1r. The specimen is very much flattened and the exact width of a ray can not be given but appears to have been about 10 mm. at the base.
In the axils of the rays the proximal inframarginal plates of adjoin- ing rays rest against each other, inside of which are two wedge-shaped interbrachial marginal plates. Orad to these and adjoining the pairs of proximal adambulacrals (oral armature pieces) is situated a single subquadrate ossicle, making three interbrachial marginal plates in each interbrachial area.
The podial openings in the ambulacral grooves are between the sutures of adjoining adambulacral and ambulacral plates along the line where these two columns adjoin. The proximal ambulacral plates orad to the axial adambulacrals are considerably modified and are to be considered as parts of the oral armature. A single rather large plate is here partially wedged between the pair of termi- nating adambulacrals, and on each end of it abuts a single broadly triangular plate, a modified ambulacral, completing the oral ends of the ambulacral columns (see drawing, pl. 20, fig. 2).
Formation and locality.—In the Richmond formation near Waynes- ville, Ohio. The holotype and only specimen is in the Harris collec- tion of the United States National Museum.
Remarks.—This species is near P. spinulosus, but apparently had wider, shorter, and more rapidly tapering rays. There appear to be but two interbrachial marginal plates in P. spinulosus, while P. exculptus has three in each area. Should the former species also prove to have three plates, a possibility, P. exculptus will be actinally identical with P. spinulosus. The wider and more rapidly tapering rays of P. exculptus can then be explained by the fact that the type- specimen is considerably distorted, since the adambulacrals and infra- marginals now lie wholly outside of the ambulacrals, which are com- pletely exposed, an unnatural condition. So long as the abacti- nal area of P. exculptus remains unknown the species had best be retained.
Cat. No. 60608, U.S.N.M.
REVISION OF PALEOZOIC STELLEROIDEA. 119 PROMOPALAZZEASTER WYKOFFI (Miller and Gurley). Plate 18, fig. 6; plate 19, fig. 2.
Palxaster wykoffi Miter and GuruEy, Bull. No. 12, Illinois State Mus. Nat. Hist., 1897, p. 46, pl. 3, fig. 27.
Original description.— Species medium size [R = 26 mm., r=8 mm. Width of ray at base 10 mm.] Rays pateliform; length about one and a half times the diameter of the body; breadth of a ray at the place of junction with the body, about two-thirds the diameter of the body; obtusely pointed.
“Marginal [inframarginal] plates wider than long and numbering about 15 in the length of half an inch from the body [or about 28 . in a complete column]. The [infra] marginal plates curve regularly around the tips of the rays. The adambulacral range curves around the ends of the rays within the marginal plates and consists of sub- quadrate plates, wider than long. They are a little shorter than the marginal plates, so that there are about 18 in the length of half an inch [about 35 in a complete column]. There are 10 oral plates [oral armature] at the junction of the adambulacral rows, which present triangular extensions toward the center of the ventral cavity. <A single irregular axillary plate rests between the terminal marginal plates and the angle formed at the junction of the adambulacral plates [this description is inadequate, see beyond for the detail]. The ambulacral plates have their greatest length across the rays, thus providing a wide ambulacral furrow. Each plate is furnished with a sharp ridge in the middle, extending from the middle furrow to the adambulacral plates.
“Our specimen exposes only the ventral side and no spines are preserved. It is a well-marked and beautiful species.”
Formation and locality —Found in the Richmond formation ‘near Madison, Indiana, by Charles W. Wykoff, in whose honor we have proposed the specific name.’’ The holotype is now in the Gurley collection of the University of Chicago (No. 6066).
Remarks.—Each interbrachial area begins orally with a pair of elongate triangular basal adambulacrals (the oral armature pieces) distally to which there are two pairs of adjoining adambulacrals followed by a single axillary ossicle and usually one but also more or less of a second pair of interbrachial marginal plates. P. wykoffi is therefore distinguished from P. exculptus in that it has orally to the single interbrachial plate two pairs of proximal adambulacrals instead of one as in the last-named species. These differences are not decided, and it may eventually be seen when more well-preserved material is at hand that they are either individual variations or due to differences in age.
120 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
P. wykoffi also greatly resembles Anorthaster miamiensis, but the interbrachial areas in the latter are entirely composed of adambu- lacral plates, there being no interbrachial marginals present. While both species attained a similar size, another difference is that the former has a greater number of plates in the adambulacral and inframarginal columns.
PROMOPALZASTER DYERI (Meek). Plate 18, fig. 8; plate 20, figs. 3-6; plate 25, fig. 1.
Palsaster dyeri Merx, Amer. Journ. Sci., ser. 3, vol. 3, 1872, p. 257; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 58, pl. 4, figs. 2a-2/f-
Original description (1873).—‘‘ Among the specimens loaned to me for study and description by Mr. Dyer, there is a very imperfect example of one of the largest known species of Silurian Starfishes. When entire, it could scarcely have measured less than 5 inches in diameter [R=probably 3 inches, or 75 mm.] across from end to end of the rays on opposite sides; and it presents a breadth of disk (as flattened by pressure) of about 2 inches [r=probably seven-eighths inch, or 22 mm.]. Its state of preservation is, unfortunately, such as not to admit of systematic description, but I think enough of its character can be given to enable the student to identify it, by the additional aid of figures.
“The dorsal side of both disk and rays is composed of numerous small pieces [with stellate extensions], with the pores between them apparently so large that these pieces only seem to touch at three to four salient points of each, so as to form a kind of reticulated struc- ture; while they each bear a little central tubercle, with a minute pit in its top for the articulation of small, short [blunt] spines, generally about 0.07 to 0.09 inch in length, and about 0.02 to 0.03 inch in thickness. [Each plate bears but one of these spines and there appear to be no other smaller spines. ]
“Tn one of the axilla between two of the rays the so-called madri- poriform body can be seen near the margin of the disk. It is nearly flat, of an obtusely subtrilobate form [probably cruciform], with a breadth or transverse diameter of 0.30 inch, and a diameter at right angles to the same of 0.24 inch [not less than 10 mm.]. Its lobed edge is directed inward toward the middle of the disk, and its middle lobe is largest, and shows the little divisions between the slits or furrows, diverging and bifureating inward like the nervation in the pinnules of some kind of ferns; while in the smaller lateral lobes these markings diverge outward.
“The ventral side is also much obscured by the adhering matrix, and numerous detached and confusedly mingled spines. A row of comparatively small, tumid, nearly square [infra] marginal pieces,
REVISION OF PALEOZOIC STELLEROIDEA. LOT
however, can be seen in places, on each side of the ambulacral furrows, and alternating with a row of similar but slightly smaller adambulacral pieces, the number of pieces in each side of these being about the same. [In the proximal portion of a ray there are 19 marginal plates in 40 mm.]. The marginal pieces seem each to connect with the adjacent range of dorsal pieces, at places in the rays, by a little central salient point only, while those of both series are roughened by numerous comparatively coarse granules [all of which bear small spines], and each piece (especially [only] of the marginal row) also shows a small central pit for the articulation of a spine. These spines are larger than those connected with the dorsal pieces, being generally about 0.22 inch in length and 0.05 inch in thickness; they are smooth, straight, rounded, slightly thickened at the attached end, and tapering at the free end to a slightly blunted point. [The adambulacral plates also possess these large spines, which are inserted on the distal inner edge of each plate.]”’
In each interbrachial area there are two pairs of wedge-shaped pieces and a single diamond-shaped interbrachial marginal plate. There are at least 4 (and may be as many as 10) pairs of adam- bulacral plates orally or in the actinal interbrachial areas, the terminal pair being of the oral armature.
Ambulacral plates much wider than long, increasing rapidly in width toward the mouth. Each plate is carimated as in P. speci- osus and proximally as in P. magnificus, with the podial openings confined to the extreme outer edge of the ambulacral furrows.
Formation and locality —Found at Cincinnati, Ohio, in the Mays- ville beds, about 200 feet below the top of the hills. The holotype is in the Dyer collection of the Museum of Comparative Zodlogy, Harvard University (No. 13). Another specimen from near the top of the Maysville at Cincinnati, preserving only the disk and showing best the actinal area, is in the Gurley collection of the University of Chicago (No. 10989). Originally this individual appears to have been larger than the holotype.
Remarks.—The relationship of this species is with P. spinulosus, but the larger size, greater development of both dorsal and ventral spines, absence of columnar arrangement of the abactinal plates, and the presence of five instead of two or three interbrachial marginal plates will readily separate P. dyert from the latter species. Even though this form appears to have attained a larger growth than P. magnificus, which it resembles in some characters, it differs in being more ponderous in its skeleton and in the far stouter and longer actinal spines.
Regarding the generic position of Palxaster dyeri, Meek wrote:
‘Possibly I should have called it Petraster dyeri, for if the apparent presence of a few disk plates on the ventral side between the mar-
122 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
ginal pieces and the adambulacral, is not deceptive, it would, in that respect, conform to the structure of that group, and differ from Palzaster, as now understood; though I am inclined to think this appearance due to the accidental displacement of the parts at the point where there are some indications of a few disk pieces.’ These pieces are not to be correlated with the accessory interbrachial plates of Petraster, for in this genus accessory plates consist of two short columns situated between the adambulacral and marginal plates and uniting in the axillary areas. In P. dyer, however, the four interbrachial marginal plates are continuous with the infra- marginal columns and evidently were derived from that series, and are not accessory interbrachials. It is true that all interbrachial plates increase the size of the disk, but in one they are derived from the inframarginal series by crowding and in the other they are interpolated, newly developed plates that force apart the columns of plates in the rays sometimes almost to the distal ends.
PROMOPALZASTER MAGNIFICUS (Miller). Plate 21, fig. 1; plate 22, fig. 1; plate 23, figs. 1-3.
Palzxaster magnificus MitLER, Journ. Cincinnati Soc. Nat. Hist., vol. 7, 1884, p. 16, pl. 4, figs. 3, 3a.
Original description.—‘The diameter or breadth of the disk is one and one-fourth inches, and the distance from the point of one ray to the point of the opposite one, if the rays were wholly preserved in the specimen under examination, would be fully 6 inches. * * *
‘“The plates upon the dorsal side are very convex, and part of them, at least, were spine-bearing, though it would seem that there was not more than one spine upon any single plate. The arrange- ment of the plates on the dorsal side of the rays is very ornamental. A single series of highly convex or conical plates, larger than the others, and each evidently bearing a central spine, occupies the middle of each ray; on either side near the margin of each ray there is a similar series, and the two intervening spaces are filled with smaller, convex plates arranged in rows which are directed diagonally forward from the plates of the side series to the plates of the central series, forming angles with each plate in the central series occupying an angle. This disposition of the plates on the dorsal side of the rays will, so far as known, serve to distinguish this species from any hitherto described.
‘The plates covering the dorsal side of the body or disk have been so much disturbed in our specimen that one can not correctly define them.
“The ambulacral furrows are wide. The marginal plates are hexagonal, about the size of the larger plates on the dorsal side of
REVISION OF PALEOZOIC STELLEROIDEA. 125
the rays, and separated from the side series by intervening smaller plates. Each bore several small spines, as shown by the small pits for their articulation. * * *
“The adambulacral plates are hexagonal and much wider than long. They are more numerous than the marginal plates near the disk, but toward the apices of the rays they interlock alternately with the marginal plates. The number on each side of a furrow in a complete ray would be 50 or more. The pits for the articulation of the spines are as numerous as they are on the marginal plates. These two series on the ventral side of the species, with numerous spines upon each plate, are in striking contrast with the plates on the dorsal side of the rays, where no plate bears more than a single spine.
‘The ambulacral plates have their greatest length across the rays, and seem to be about as numerous as the adambulacral ones. An angular depression marks the center of each ambulacral furrow, upon each side of which a sharp ridge arises upon each ambulacral plate, and curving forward and outward abuts against an adambula- cral plate.”
. Emended description.—The largest specimen, the holotype, meas- ures R = (about) 67 mm.,r=17 mm., R=nearly 4r. Another speci- men: R=58 mm., r=15 mm., R=nearly 4r.
Abactinal surface very ornamental. Medially along each ray there is a radial column of highly convex plates, and two columns of similar plates, the supramarginals, are situated near the margin. Between the inframarginal, supramarginal, and radial columns are very nu- merous diagonal rows of smaller conical or angular plates, from 2 at the apex of the ray to 14 at base of same in each row on each side of the radial column. This may be stated in another way. Between the radial and supramarginal columns and again in the ambital area, or between the supramarginals and inframarginals, the diagonal rows have from one to seven plates in each area. These rows are directed diagonally and distally across the rays from the sides to the median column, the apex of the angle thus formed being occupied by the larger plates of the radial column. All of these smaller plates appar- ently bore a single short spine. Between all of the diagonal rows are inserted both proximally and distally numerous minute, conical, irregular-shaped plates. The supramarginal columns continue across the disk and those of adjoining rays unite in the axillary areas. The . radial columns also extend over the disk but do not attain the center, and the diagonal arrangement of the small plates ceases near the proximal portion of the rays. The pattern arrangement of the disk plates can not be made out since their original position is disturbed.
Madreporite quite large, quadri-lobate in outline, depressed, convex and very finely radiately striate. It is situated in one of the axillary
124 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
areas, less than 4 mm. from the margin. Against it rest two columns of supramarginal plates.
The inframarginal plates, of which there are at least 45 in each column, are distally small and subquadrate but proximally increase rapidly in size and at the base of the columns are three to four times as wide as long. These plates bear numerous pitted pustules upon which articulated short, sharp, smooth spines. The columns of ad- joining rays meet in the axils and continue into the interbrachial areas.
The adambulacral plates are like the inframarginals but do not increase so rapidly in width as those plates and are somewhat more numerous, there being in a complete ray about 52 in a column. Proximally some of the large plates are broken into two or three _often very convex ossicles. In addition to the small spines like those of the inframarginals, each plate bears on its ambulacral edge a prom- inent socket in which articulated along, thick, smooth spine. The adambulacral plates in the proximal third of the rays each have a small, more or less wedge-shaped, carinated, accessory adambulacral plate. In this region these ossicles separate the adambulacrals from the ambulacrals and beneath the accessory adambulacral plates are the podial openings. Five or six adambulacral plates of each column abut against the interbrachial marginal plates, while five or six pairs continue orally, the terminating pieces being of the oral armature.
Ambulacral furrows wide, increasing in width proximally. An angular median sinus marks each ambulacral furrow. Ambulacral plates short but wide, slightly overlapping proximally, and one to each adambulacral plate. All of the plates are strongly carinated, the carina in the distal two-thirds converging medially and proximally. In the proximal third the carinz gradually are changed in form and are there arranged inforked pairs. In other words, the caring adjoin the accessory adambulacrals, are arranged in pairs, continuing ad- joining and, straight for a short distance, and then diverge in broad curves, terminating near the center of the ambulacral groove. This arrangement produces in the proximal portion of the ambulacral furrows four columns of ovoid pits, all terminating laterally into podial openings. Every other podial opening belongs to the same column, one series beneath the adambulacrals, the other gradually passing medially in the ambulacral grooves. In the distal two-thirds, however, the podial openings are arranged in single columns, one to each ambulacral plate and issuing from underneath the adambulacrals.
Interbrachial areas with seven plates, each composed of two prox- imal inframarginals, beneath which are two pairs of interbrachial marginals and a single diamond-shaped axillary marginal plate. All bear similar spines and ornamentation on the inframarginals. Some- times one of the distal interbrachial marginals may be divided and
*
REVISION OF PALEOZOIC STELLEROIDEA. 125
the arrangement of the interbrachial plates made irregular. In a specimen from Jefferson County, Indiana, there are 3 pairs of inter- brachial marginals instead of 2 as in the Ohio individuals. There- fore there are also more adambulacrals here, 14 pairs against 10 in the typical specimens.
Formation and locality —Two free specimens of this magnificent starfish were found in the Richmond formation near Waynesville, Ohio. Originally pieces of these two individuals were glued together as one specimen, which is the cause of our figures being less perfect than Mr. Miller’s. Fragments of seven other individuals were found in the vicinity of Waynesville. In the University of Chicago col- lection (No. 10981) there is a specimen from Jefferson County, Indiana, apparently of this species. Mr. Vaupel secured the distal portion of a ray of an apparently young example of this species in the Maysville beds on Rohs Hill, Cincinnati, Ohio, and Mr. Ulrich has fragments of four individuals from the Maysville strata about Cincinnati, and Covington, Kentucky.
Remarks.—This species is readily separated from the other species of Promopalzaster by the marked diagonal rows of abactinal plates. Actinally P. magnificus is readily distinguished from P. exculptus and P. spinosus in having five instead of three interbrachial marginal plates in each area, in the rapidly increasing size of the plates in the inframarginal and adambulacral columns, and in the proximal am- bulacral plates. P. speciosus differs at once from P. magnificus in that its abactinal plates are arranged in regular longitudinal columns, are far less numerous, larger and are all nearly of a size.
This is one of the largest and best preserved of American Paleozoic starfishes. P. dyert may be a larger species but is distinguished abac- tinally not only by the arrangement and difference in the forms of the plates but also by the short, thick, blunt spines which now ap- pear to have no.definite arrangement, while P. magnificus has all of its very fine spines arranged in diagonal rows like the plates.
Cat. Nos. 40883, 60621, 60622, U.S.N.M.
ANORTHASTEHRIN 4, new subfamily. Aberrant Promopaleasteride with the axillary and interbrachial areas composed entirely of adambulacral pieces. Contains: Anorthaster. ANORTHASTER, new genus. Plate 13, fig. 4; plate 20, fig. 1.
Anorthaster ScuucHert, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 11.
A+ orthos + aster = out of the regular, in reference to the completely adambulacral nature of the interbrachial areas.
126 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Generic characters.—Disk small, with apparently small interbrachial arcs. Rays five, of moderate length and tapering at first slowly and then rapidly distally.
Abactinal area unknown.
Inframarginal plates small, the columns not attaining the axils, but resting upon the second enlarged axillary adambulacral plate.
Adambulacral plates distally like the inframarginals, increasing in size slowly proximally until near the axillary region, where four - plates suddenly attain great width, terminating in the axils of the rays and here suppressing the inframarginal plates. Eight inter- brachial adambulacrals of varying form are situated orally to the two large axillary adambulacral plates, and at first give one the impression of slender interbrachial areas of the same nature as in Promopaleaster. These plates, however, are not interbrachial marginals, as in other genera, and derived by the oral crowding of proximal inframarginals. They are distinctly adambulacral ossicles, forming slight interbrachial areas, and, with the axillary adambulacrals, form small ares. For the shape and position of these plates see figure 1, plate 20.
Ambulacral plates alternating, slightly carinated, and very short but wide. In the distal region they are as long as the adambulacral plates, but proximally decrease in length where there are nearly two of them to one adambulacral ossicle. . Podial openings between every — other plate through the sutures of adjoining pieces at their outer edge and immediately beneath the inner edge of the adambulacral ossicles. The proximal plates of each column are modified into oral armature pieces that are slightly tumid, as long as wide, and sub- triangular in outline. Between the proximal ambulacrals and orad to the proximal interbrachial adambulacrals are situated additional single, very small, quadrangular oral armature plates.
Genoholotype and only species —Palxaster miamiensis Miller.
Distribution.—Ordovicic, Richmond formation, near Waynesville, Ohio.
Remarks.—The suppression of the inframarginal plates in the axils of the rays by two of the adambulacral plates of each column and the oral continuation beneath the latter of four pairs of adambulacral plates holding an interbrachial position distinguish this genus from Promopaleaster, to which it otherwise seems very closely related. This character also distinguishes it from all other associated genera.
The interbrachial structure of Anorthaster appears abnormal. In Mesopalxaster and Promopaleaster the proximal inframarginal plates are crowded orally and form interbrachial areas; in Anorthaster their formation is effected in the opposite way, not by the inframarginals, but by the adambulaerals. This character is seen in a single speci- men, but it is so regularly developed and well preserved as to indicate a normal and not a pathologic or abnormal condition.
REVISION OF PALEOZOIC STELLEROIDEA. 127 ANORTHASTER MIAMIENSIS (Miller). Plate 13, fig. 4; plate 20, fig. 1.
Palxaster miamiensis MrtLER, Journ. Cincinnati Soc. Nat. Hist., vol. 3, 1880, p. 148, pl. 4, fig. 3.
Original description.‘ Pentagonal; rays about one and a half times the diameter of the body, or about nine-tenths of an inch; diameter of the body about six-tenths of an inch; breadth of a ray at the point of junction with the body a little more than half the diameter of the body, or about seven-twentieths of an inch; rays obtusely pointed.
‘Marginal plates wider than long, and numbering about 12 in the length of half an inch from the body. Two marginal plates form the junction of the rays. Ambulacral furrow wide, the plates being more than twice as long as wide. There are about 18 ambu- lacral plates in a length of one-half inch, and each one is provided with an angular ridge tapering from the marginal plates to the furrow.”
Emended description.—R = 23 mm.,r=7 mm., R=3.2r. Width of rays at base 8 mm.
Rays tapering very slowly in the proximal half, but more rapidly distally.
Abactinal area unknown.
Inframarginal plates about 16 in each column and subquadrangular in outline. These ossicles do not continue into the axils, but rest upon the second large axillary adambulacral plate.
Adambulacral plates about 18 in each column, like the infra- marginal pieces, increasing in size proximally, while the two axillary ones are suddenly enlarged, extend to the margin of the disk, and have the position of marginal ossicles. Orally to the latter the adambu- lacral plates continue as interbrachial ossicles. The distal pair is large and both are wedge-shaped, followed by two pairs of quite small quadrangular plates and a final pair of long and narrow plates; in all there are, therefore, 22 adambulacral plates in each column. The interbrachial adambulacral plates are terminated by a single quadrangular oral plate wedged in between the proximal ambu- lacrals.
Ambulacral furrows very wide, broadly gutter-shaped. Ambu- lacral plates about 30 in a column, slightly alternating, decidedly wider than long proximally, increasing in length distally, and finally becoming about as wide as long near the apex of aray. Each plate is slightly carinated, the ridges crossing the plates from the lateral distal edge to the medial proximal edge. The proximal ambulacral plates are modified, conspicuous, and subtriangular in outline. Podial openings between two adjoining plates in alternate sutures at
50601°—Bull. 88—15——9
128 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
their extreme outer edges and immediately inside of the adambu- lacral plates.
Formation and locality.—In the Richmond formation, near Waynes- ville, in Montgomery County, Ohio. The holotype is in the Harris collection of the United States National Museum.
Remarks.—This species has a general resemblance to some of the Promopaleasters, particularly P. bellulus and P. wykoffi, but the peculiar arrangement of the axillary and interbrachial adambulacral plates will distinguish it not only from them but from all other Ordovicic asterids.
Cat. No. 40880, U.S.N. M.
Family XENASTERID AE Schondorf.
Xenasteride GreGorY, Geol. Mag., dec. 4, vol. 6, 1899, p. 346; Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.
Palzgoniasteride Stiirtz, Paleeontographica, vol. 36, 1890, p. 247 (not opp. 246).
Xenasteride ScuHbnvoRF, Paleeontographica, vol. 56, 1909, p. 105; Jahrb. nassau- isch, Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 25; vol. 63, 1910, pp. 244, 250.
Progressive Phanerozonia having the general characters of the Promopaleasterine, with the addition of accessory interbrachials. The ambulacral and adambulacral plates are directly opposite one another and do not waver between the slightly alternate and opposite arrangement in the Promopaleasterine. Podial openings in two columns in each ambulacral furrow, the apertures lying between each four adjoining plates, that is, between two adambulacrals and two ambulacrals.
Contains:
Xenaster Simonovitsch. Agalmaster Schéndorf. Rhenaster Schéndorf. Eifelaster Schondorf. Trimeraster Schondorf.
Schéndorf defines the family as follows dedicat out much of his detail):
Lower Devonic starfishes with well-developed supramarginals and usually stilllargerinframarginals ; the latter aresomewhat more numer- ous than theformer, causing them to be unequallysuperposed. Ambu- lacra opposite one another and opposite the adambulacrals; podial openings in tworows. Actinally each interradius has either three or five interbrachial plates; abactinally this area is filled with small accessory plates and margined only by inframarginals. Diskskeleton consisting of small separated pieces, a central disk plate, five primary radialia, five primary interradialia, and more or less of accessory disk
REVISION OF PALEOZOIC STELLEROIDEA. 129
ossicles. Rays with three columns of plates, one radial and two supramarginal, that may or may not be separated from one another by small accessory pieces. Madreporite dorsal and interradial.
Genus XENASTER Simonovitsch emend. Sch6ndorgf. Plate 24.
Archxasterias MULLER, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 12, 1855, pp. 6, 8 (Archxasterias founded in error).
Xenaster StmoNovitTscH, Sitzb. mat.-naturw. Classe Akad. Wiss., Wien. vol. 64, Abt. 1, 1871, p. 88.—Scuénpvorr, Palzontographica, vol. 56, 1909, pp. 42, 105 (complete synonymy given here); Jahrb. nassauisch. Ver. Naturk., Wies- baden, vol. 62, 1909, p. 26.
Generic characters.—Xenaster has its nearest relationship in Devonaster. No detailed description need be given, since the splendid illustrations of Schéndorf give all the necessary characters. It differs from Devonaster as follows:
In Devonaster there is but a single interbrachial plate in each actinal axil, the axillary interbrachial, while in Xenaster there are two pairs of interbrachial marginals and a single axillary inter- brachial plate; in other words, five interbrachial platés instead of one (1+2+2). Inaddition to these plates in Xenaster, the interbra- chials are more or less surrounded by small accessory pieces, and then other similar plates separate the inframarginal and adambulacral col- umns to near the outer third of the rays. The inframarginal plates in Xenaster do not increase so rapidly in width proximally as do these plates in Devonaster, and while the interbrachial areas are of about the same size in both genera, the space occupied by the additional interbrachial marginal and accessory interbrachial ossicles in the former is taken up in the latter genus by the increased size of the inframarginal pieces.
Abactinally Xenaster has the generic characters of Devonaster. The plates in all the columns of the former genus are more prominent and rounder, particularly the accessory plates, of which there appear to be less than in Xenaster. The center of the disk in both genera is occupied by a small central disk plate, but there are many more accessory plates around it in Devonaster than in Xenaster. In both genera the supramarginal columns converge proximally, producing small disk areas between the infra- and supramarginal plates occu- pied by ambital accessory plates.
Madreporite large and striate in Xenaster.
Genotype.—X. margaritatus Simonovitsch.
130 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Distribution.—Restricted to the Lower Devonic of Germany. The species are:
X. margaritatus Simonovitsch. X. dispar Schondorf.
X. elegans Schéndorf.
X. (?) rhenanus (Miller).
Remarks.—Miiller in his description of Asterias rhenana,' the geno- type of Archxasterias, notes that the adambulacral plates of adjoining columns alternate and that the ambulacral columns “‘have the appear- ance also of alternating,’ which if established would be very remark- able, and would justify the creation of a distinct genus Archzxasterias for this asterid of the Rhine grauwacke. Schdndorf shows that these statements of Miiller’s are very faulty and further that the genus Archxasterias has not been defined so as to be recognizable. Under these circumstances it was best for Simonovitsch to disre- gard Archeasterias and to establish a new generic name for his species margaritatus. There is no Paleozoic genus of starfishes better described or illustrated than this one by Simonovitsch, and should it ever prove that Asterias rhenana Miller is identical with Xenaster margaritatus, a possibility, the latter should not be made to give way to the former on the ground of priority. It is an injustice to extend the law of priority indiscriminately to all work, and to reject Archeasterias is no reflection on the work of Miller, as his material was very poor and his work of early date in paleontology. He pub- lished at a time when it was very desirable to learn anything what- ever about Paleozoic starfishes.
As pointed out above, Xenaster has much of the structure of Devonaster, yet it differs in the important character of having numerous accessory interbrachial plates. This feature seemingly relates it with forms like Palasterina which have a great abundance of accessory interbrachials, yet in no interbrachial area of this genus are there axillary interbrachials or interbrachial marginals. In other words, the Palasterina type of disk is made by the intercalation of accessory plates between the inframarginals and adambulacrals, whereas in Devonaster it is accomplished by the greater width of the inframarginals and by the oral crowding of a plate which in primitive forms is an axillary marginal. Devonaster although from younger strata is more primitive than Xenaster because of its simpler inter- brachial actinal structure. If it were not for the accessory inter- brachials, Xenaster would be closely related to Promopaleaster which also has a number of proximal inframarginals crowded into the inter- brachial areas. It is the Promopaleaster stock out of which Xenaster probably developed, while Devonaster apparently came through Mesopaleaster.
1 Verh. naturh. Ver. preuss. Rheinl., etc., vol. 12, 1855, pp. 6, 8.
REVISION OF PALEOZOIC STELLEROIDEA. ToL
XENASTER MARGARITATUS Simonovitsch emend. Schéndorf.
=z Plate 24, figs. 1,2.
Xenaster margaritatus (part) Stmonovirscy, Sitzb. mat.-naturw. Classe Akad. Wiss., Wien, vol. 64, Abt. 1, 1871, p. 88, pls. 1, 2.—ScuéNnporr, Palzon- tographica, vol. 56, 1909, pp. 48, 106, pl. 7, figs. 1, 3, 4; pl. 8, fig. 1; pl. 1, figs. 2, 3, 10, 11 (complete synonymy given here); Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 26, pl. 2, figs. 1, 2—Spencrer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontogr. Soc. for 1913), 1914, p. 30.
This species is one of the best described and illustrated of Paleozoic starfishes and does credit to its author, and to its subsequent reviser, Schéndorf. It occurs rarely in the Lower Devonic (Upper Coblen- zian) as natural molds at Niederlahnstein on the Rhine, Germany.
XENASTER DISPAR Schéndori.
Xenaster margaritatus (part) Stmonovirscn, Sitzb. mat.-naturw. Classe Akad. Wiss., Wien, vol. 64, 1871, Abt. 1, pl. 2, figs. 2, 2a, 2b.
Xenaster dispar ScHONDORF, Palzeontographica, vol. 56, 1909, pp. 50, 84, 106, pl. 9, fig. 1; pl. 11, fig. 18; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 28, pl. 3, fig. 3.
From the Upper Coblenzian at Niederlahnstein, and Miellen,
Germany. y XENASTER ELEGANS Schindort.
Xenaster margaritatus FOLLMANN (not Simonoviisch), Jahrb. naturh. Ver. preuss. Rheinl., etc., vol. 48, 1891, p. 150. Xenaster elegans ScH6NvoRF, Palzeontographica, vol. 56, 1909, pp. 53, 107, pl. 9, figs. 2, 3; pl. 11, figs. 4, 12; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 40, pl. 4, figs. 6, 7. From the Lower Devonic (Coblenz quartzite) at Konigstuhl, near
Rhens, Germany. XENASTER (?) RHENANUS (Miiller).
Asterias (Archexasterias) rhenana Mtuter, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 12, 1855, p. 6, pl. 1, figs. 4-6.
Xenaster (2) rhenana Scubnvorr, Palzontographica, vol. 56, 1909, pp. 55, 107, text fig. 2 (complete synonymy given here); Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 28.
This species is based upon incomplete material and can not be made out fully. It seems probable that it is a species of Xenaster and closely related to X. margaritatus Simonovitsch. The examples are in the Berlin Museum and were found in the Lower Devonic at Winningen, near Coblenz, and Kemmenau, near Ems, Germany.
Genus AGALMASTER Sch6éndorf. Text fig. 9. Agalmaster Scu6nvorr, Paleeontographica, vol. 56, 1909, pp. 58, 107; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 29.
Original remarks.—Agalmaster differs from X enaster in the following characters: Forms larger, broader rayed, with flat actinal but highly arched abactinal plates. Supramarginals much stronger than the large inframarginals and projecting considerably beyond these.
132 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Abactinal interbrachial area small, and occupied in the main by two axillary inframarginals; actinally this area has the same structure as Xenaster. Madreporite dorsal.
Genoholotype (the writer here selects the first species).—A. miel- lensis Schéndorf. Other species are A. grandis Schéndorf and A. intermedius Schéndorf, both trom the Lower Devonic of Germany.
Remarks.—The only character. that may be of generic value and that at present distin- guishes Agalmaster from Xenaster is that in the former genus the supra- marginals margin the rays instead of the in- framarginals, as is the case in the latter genus. In a second species (A. grandis) the small ac- cessory interbrachials i crowd in between all the
pairs of interbrachial Fig. 9.—AGALMASTER MIELLENSIS, AFTER SCHONDORF. SCHEMATIC 7 ARRANGEMENT OF ABACTINAL PLATES. R2 AND R3, SECOND AND marginals and, further, THIRD PROXIMAL RADIALIA; J71, PRIMARY INTERRADIALIA; cdp, there are far more of CENTRAL PLATE; mdp, MADREPORITE; m0, SUPRAMARGINALIA; these pieces b etween mu, INFRAMARGINALIA; Pifm, PRIMARY INTERRADIALIA.
the inframarginals and adambulacrals; in fact, there are three to four columns of these in- stead of one (as in A. miellensis).
AGALMASTER MIELLENSIS Schéndorf. Text fig. 9.
Agalmaster miellensis ScHbnvDoRF, Paleeontographica, vol. 56, 1909, pp. 58, 107, text fig. 3; pl. 8. fig. 4; pl. 9, fig. 4; pl. 11, figs. 1, 5; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 29, pl. 3, fig. 2; pl. 4, figs. 1, 2.
A single specimen with the rays about 43 mm. long was found in the Lower Devonic (Upper Coblenzian) at Miellen-on-the-Lahn, Germany. AGALMASTER GRANDIS Schéndorf.
Xenaster margaritatus Stmonovitscu (part), Sitzb. mat.-naturw. Classe Akad. Wiss., Wien, vol. 64, Abt. 1, 1871, pl. 2, figs. 3, 3a.
Agalmaster grandis ScubnporF, Paleontographica, vol. 56, 1909, pp. 62, 108, pl. 9, fig. 5; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 29, pl. 3, fig. 1.
One specimen (Xenaster margaritatus Simonovitsch, part) from the Lower Devonic (Upper Coblenzian) at Niederlahnstein on the Rhine, Germany.
REVISION OF PALEOZOIC STELLEROIDEA. iso AGALMASTER INTERMEDIUS Schéndorf.
Agalmaster intermedius ScH6NDoRF, Palezontographica, vol. 56, 1909, pp. 82, 108, pl. 11, fig. 14; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 30.
From the Upper Coblenzian at Miellen-on-the-Lahn, Germany.
Genus RHENASTER Schondorf. Text fig. 10. Rhenaster ScHbNvDoR?F, Paleontographica, vol. 56, 1909, pp. 65, 108, pl. 8, fig. 3 pl. 10, figs. 1, 4.
Remarks.—Rhenaster is a small form and differs from Xenaster, Agalmaster, and Devonaster in the complete absence of all abactinal accessory plates, allow- ing theradial and supra-
marginal pieces to ad- oe ey
join one another closely. a Dorsal axillary disk KE
areas not completely Gs 2R5 ZO
but almost absent, res OK
main lying wholly upon
the inframarginals and SEO
the two columns of SH % plates together margin- we BOE XO ing the rays. There
also are no accessory oe
plates of any kind on : es Fig. 10.—REENASTER SCHWERDI, AFTER SCHGNDORF. SCHEMATIC the actinal side. Other- ARRANGEMENT OF ABACTINAL PLATES. SYMBOLS AS IN FIG. 9.
supramarginals in the NOY Gio Oo
wise the generic struc-
ture is that of Xenaster, except that in Rhenaster the first pair of
interbrachial marginals are not yet pushed so much orally and they
almost take part in margining the axils. Madreporite unknown. Genoholotype and only species (one specimen).—R. schwerdi Schén-
dorf, from the Lower Devonic (Upper Coblenzian) at Dérrbachtal,
near Coblenz, Germany.
Genus EIFELASTER Schondorf. Exfelaster Scu6nvorF, Paleontographica, vol. 56, 1909, pp. 70, 108, pl. 10, figs. TOs
Remarks.—This genus is very closely related to Rhenaster and differs only in that there are small dorsal interbrachial areas between the adjoining proximal portions of the supramarginal columns, and these are filled with a small number of accessory ambital pieces. The outer portion of these ambital areas is made up of the two basal
inframarginals that occupy the axils of the ventral side.
134 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
The genoholotype and only species, EL. follmanni, occurs in the Lower Devonic (Lower Coblenzian) at Landscheid, near Wittlich, in the Eifel, Germany. Plastotypes of the holotype were made for the writer by Professor Jaekel, of Greifswald, and these are now in the Yale University collection.
Genus TRIMERASTER Schondorf. Plate 19, fig. 1.
Trimeraster ScHONDORF, Paleeontographica, vol. 56, 1909, pp. 68, 108, pl. 7, fig. 2; pl. 10, figs. 5, 6.
Remarks.—Trimeraster is a small form, very closely related to Xenaster, and can be distinguished generically only in that the former has inside of the inframarginals but one pair of interbrachial margi- nals and a single axillary interbrachial in each interbrachial field instead of the five plates of the latter genus.
Genoholotype and only species (one specimen).—T. parvulus Schén- dorf, from the Lower Devonic (Coblenz quartzite) at Kénigstuhl, near Rhens, Rhine Valley, Germany.
NEOPALAASTERID,, new family.
Progressive Phanerozonia without interbrachial arcs. The columns of supra- and inframarginal plates wholly superposed. Madreporite abactinal. Well-developed ocular plates present. Ambulacrals alter- nating. Disk with a ring of large plates of basal, radial, and inter- radial ossicles.
Contains:
Neopalzaster, new genus.
The origin of this family is uncertain, but it seems to be related to the Promopaleasteridx, since its essential characters are those of the Mesopaleasterine. In the latter the supramarginals do not com- pletely overlie the inframarginals making one consolidated column as in Neopaleaster. It is, so far as known, the oldest family developing ocular plates. This fact is of considerable importance for it means that the oculars were originally basal radialia, and that they have progressively wandered from the disk and then remained at the tip of the rays.
NEOPALAASTER, new genus.
Plate 13, fig. 5; pl. 23, fig. 4. Neopalxaster ScHucHERT, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 26,
Generic characters.—Disk of medium size, without interbrachial arcs. Rays five, short and tapering rapidly.
Abactinally the disk has a small central plate surrounded by numerous smaller plates. Bounding the smaller accessory disk
REVISION OF PALEOZOIC STELLEROIDEA. 135
plates is a ring of very large, thick, tumid, variously shaped, radial and interradial plates. Of the latter there may be one plate inside of the basal supramarginals of adjoining columns, or this plate may be divided, when the pieces appear as inwardly crowded supramar- ginals. Laterally and distally upon the interradials are situated the large basal radial plates. The rays are bounded laterally by columns of large, thick, subquadrate, tubercular supramarginals terminated dis- tally by single ocular plates. These plates appear to be common to both the actinal and abactinal areas and must therefore be the united infra- and supramarginal columns. Between the supramarginals dis- tally appear single small isolated plates which proximally become larger and continuous, forming an inconspicuous column of radial ossicles. On each side of this column are inserted a number of appar- ently irregularly arranged small accessory plates which are like those of the disk. All of the plates of the abactinal area are finely tuber- culose, these points being for the attachment of very fine, short spines.
Madreporite small, rounded, not very convex, very finely radially striated and resting directly upon two basal supramarginal plates of adjoining rays.
Ocular plates small but distinct, one terminating each ray and rest- ing against the distal marginal plates.
Supra- and inframarginal plates large and conspicuous, apparently firmly united and indistinguishable laterally as separate columns. Abactinally the supramarginal plates are wider and overlie more or less the adambulacrals.
Adambulacrals smaller than the inframarginals but otherwise resemble the latter.
Ambulacral grooves narrow. Ambulacral plates alternating, about as numerous as the adambulacrals, +-shaped, with the podial open- ings between adjoining plates.
All other actinal characters unknown.
Genoholotype and only known species.—Paleaster crawfordsvillensis Miller. From the Keokuk crinid beds near Crawfordsville, Indiana.
Remarks.—Neopalxaster retains a very primitive abactinal plate structure and calls to mind Hudsonaster, Palxaster, and typical Mesopalexaster. Itis distinguished from these early Paleozoic genera by the complete consolidation of the supra- and inframarginal plates into one column, and the presence of ocular plates. The inter- brachial area is unknown in Neopaleaster, but its abactinal structure seems to indicate a single interbrachial plate in each area bounded distally by two basal inframarginal plates. If this interpretation is correct, then this character will further distinguish Neopalexaster from Hudsonaster and Palzaster.
136 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. NEOPALZ ASTER CRAWFORDSVILLENSIS (Miller). Plate 18, fig. 5; plate 23, fig. 4.
Palxaster crawfordsvillensis MrtER, Journ. Cincinnati Soc. Nat. Hist., vol. 2, 1880, p. 256, pl. 15, fig. 3; N. Amer. Geol. Pal., 1889, p. 265, fig. 379.
Original description.—‘This species is founded upon the dorsal view of asingle specimen. The rays are longer than the diameter of the body, and not of uniform size. They are flattened or depressed in the middle, as is also the central part of the body. Many of the plates possess a central tubercle or small spine, and probably all of them did.
‘The marginal plates are large, somewhat elliptical in outline, and have their shorter diameters in the direction of the length of the rays. There are about 12 plates on each side of a ray, and they come together at about the eighth plate from the body, though in the ray opposite the madreporiform tubercle they come together at the seventh. The space between the marginal plates of each ray is filled with smaller plates; three of these unite the larger plates at the body, but they diminish in number toward the apex of the ray, and cease at the eighth plate. In addition to the two large plates which form the junction of the rays with the body, a few large plates cover the outer part while the central part is covered by smaller plates. The madreporiform tubercle is supported by three plates, two of them are large marginal plates, which form a junction between two rays, and the other is a large plate within, forming part of the covering of the body.”
Emended description—The type-specimen measures: R=22 mm., r=7mm., R=3.1r. Width of rays at base 7 mm. Another speci- men in the Museum of Comparative Zoélogy has rays 3 mm. longer.
Rays short, tapering rapidly. Disk rather large for a small species.
Abactinally the disk has a central circular plate surrounded by numerous small, conical, irregularly disposed, accessory plates, among which are a few larger pieces usually adjacent to the large interradial plates. Outside of the small disk plates is a ring of very large, irregu- larly shaped, radial and interradial plates. Five of these are inter- radial in position, and are situated just within the basal plates of adjoining-supramarginal columns. These plates may remain normal as a single plate or may be divided into two plates, when they some- what resemble inwardly crowded supramarginals. Upon these laterally and distally rest five large radial pieces, the basal plates of the radial columns. It is very probable that the radial columns are continuous from the basal plate to near the distal portion of the ray, where a few of these plates are much reduced in size and are
REVISION OF PALEOZOIC STELLEROIDEA. 137
separated and wedged in between the adjoining four supramarginal ossicles. There appear to be 10 or 11 of these in a column. On each side of the radial columns in the proximal half of each ray are a number of small accessory plates arranged in irregular columns. All of the abactinal plates are more or less convex and bear numerous small pustules clustered around a larger central one, all of which bore small spines.
Supramarginal plates very conspicuous, subquadrangular in out- line, generally a little wider than long, with numerous small pustules, among which toward each lateral edge is a large one upon which probably articulated prominent spines. There are from 11 to 13 of these plates in each column. In the distal third of a ray both columns approximate and adjoin each other closely. Each supra- marginal plate lies wholly and directly over an inframarginal and the pieces appear as one consolidated plate with the abactinal side convex and the actinal nearly flat. The supramarginals are the widest and extend in part over the adambulacrals.
Madreporite small, circular in outline, slightly convex and very finely radially striated. It lies directly upon two basal supramar- ginal plates of adjoining rays and directly outside of one of the large interradial plates.
An ocular plate terminates each ray.
Inframarginals apparently like the supramarginals excepting distally, where they are nearly twice as long as wide.
Adambulacral plates smaller than the inframarginals, nine in the space occupied by five of the latter, somewhat wider than long, convex, and covered with numerous small pustules.
Ambulacral grooves very narrow in the distal region. The ambu- lacral plates appear to be as numerous as the adambulacrals, and are + -shaped, with the podial openings between the plates in about the mid-width of the column.
All other actinal characters are unknown, since the two specimens expose the abactinal area, though one has portions of the plates removed, revealing the actinal characters described.
Formation and locality.—The type-specimen is in the Harris collection of the United States National Museum, and another specimen is in the Dyer collection of the Museum of Comparative Zodlogy (No. 4). Both were found in the crinid beds of the Keokuk group of the Lower Carboniferous at Crawfordsville, Indiana.
Remarks.—There is no Carboniferous asterid with which Neopale- aster crawfordsvillensis can be confounded.
Cat. No. 60607, U.S.N.M.
138 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Family PALASTERINID Gregory (emend.).
Palzasterinide Grecory (part), Geol. Mag., dec. 4, vol. 6, 1899, p. 348 (contains Palasterina, Schenaster, and Schuchertia); Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.
Lindstromasterine GREGORY (part), Geol. Mag., dec. 4, vol. 6, 1899, p. 346 (contains Lindstromaster and Uranaster).
Palexasterindx Stiintz, Paleeontographica, vol. 36, 1890, p. 246.
Progressive Phanerozonia developing large interbrachial arcs. Ambulacral plates more or less alternate. Madreporite abactinal. Disk large, pentagonal, and the rays separated by well-developed interbrachial arcs. The inframarginal plates bound the animal and are separated from the adambulacrals more or less completely by a varying number of interbrachial plates.
Abactinal surface with longitudinal columns of radial, supra- marginal and accessory columns of plates, or the radial columns may be reduced or even replaced by transverse rows of small accessory pieces. The central region of the disk may retain a ring of larger basal radial and supramarginal pieces.
Contains:
Petraster Billings. Lindstrémaster Gregory. Palasterina McCoy. Uranaster Gregory. Palzostella Stirtz. Pseudopalasterina Stirtz.
Genus PETRASTER Billings. Plates 23, 26, 27.
Petraster Bruurnas, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 79.— Hatz, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, pp. 283, 294; rev. ed., 18681870, pp. 325, 337.
Palzaster (part) ZrrteL, Handb. Pal., vol. 1, 1879, p. 452.
Palzasterina of some AUTHORS.
Generic characters.—Disk and interbrachial arches more or less large. General shape pentagonal. Rays five, short and slender or stout and tapering rapidly.
Abactinal area of rays distally with one medial radial, two supra- marginal and two inframarginal columns of plates. Between the radial and supramarginal columns proximally are inserted columns of accessory plates. In P. speciosus there are five on each side of the radial column. Between the supramarginal and inframarginal columns in the axillary and basal ray regions are inserted columns of ambital plates. In P. speciosus there are three. The plates are more or less stellate, with numerous subcircular openings in the angles between adjoining plates.
REVISION OF PALEOZOIC STELLEROIDEA. 139
Inframarginal plates bounding the entire outer edge of the animal, conspicuous, closely adjoining, not stellate and common to both the actinal and abactinal areas.
Madreporite radially striate, abactinal.
Adambulacrals closely adjoming the inframarginals in the distal portion of the rays but proximally the former are separated from the latter by more or less numerous, small, accessory interbrachial plates. The adambulacrals may be of nearly the same size, or considerably wider than long in the mid-length of the column. The adambula- | crals of adjoining columns meet orally in a pair of larger triangular plates, the oral armature.
Interbrachial areas more or less large and the space between the inframarginal and adambulacral columns filled with a variable number of accessory interbrachial plates.
Ambulacrals slightly alternating, about as numerous as the adam- bulacrals, each with an L-shaped, proximally converging carina. Podial openings through the outer proximal corner of the plate and proximal to the carina. Grooves narrow, regularly tapering.
Genoholotype (type by monotypy).—Petraster rigidus Billings. The above diagnosis is based on the genotype and Palzasterina speciosa Miller and Dyer.
Distribution.—Ordovicic of North America, Siluric of Australia.
The species are:
P. rgidus (Billings). Trenton.
P. speciosus (Miller and Dyer). Maysville, Richmond. P. (?) americanus (D’Orbigny). Maysville.
P. smythi McCoy. Siluric of Australia.
Remarks.—While Billings has correctly pointed out the diagnostic characters of Petraster, yet the genus has been very imperfectly understood. This may partly be accounted for in that he later also included a specimen of Hudsonaster matutinus (Hall), which of course fails to have the essential generic character of Petraster, namely, the interbrachial accessory plates. The following is Billings’ original description:
‘‘This genus has both marginal and adambulacral plates, with a few disk-plates on the ventral side. The general form is deeply stellate, and the rays long and uniformly tapering. A single specimen has been collected, and as it shows the underside only, the characters of the dorsal surface can not be given. The structure of the mouth is also unknown. Generic name from petra, a stone.
“Tt differs from Palasterina by the presence of large marginal plates outside of the disk-plates [that genus has small marginals], and still more from Stenaster, which has neither disk nor marginal plates. It is allied to Astropecten.”
140 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Professor Hall at first recognized the distinctness of Petraster, since he wrote as follows (1870):
“The character of Petraster here described, and illustrated in the figure (3a, pl. 9), gives an intercalated partial range of disk-plates, between the adambulacral and marginal plates, which will separate these forms from any of the Paleasters in my collection.”
On a later page, after an examination of the genotype, he added a ‘‘Note on the genus Petraster’’ in which he concludes that the specimen was injured during life, as shown by the unequal distribu- tion of the accessory interbrachial plates, and further that one ray is ‘‘without intercalated plates on either side.” He adds: ‘‘ This view is sustained by the fact that the other parts have the ordinary structure of Palxaster, and in all other respects the specimen agrees with the typical Palxaster matutina.” The genotype was studied at Ottawa by the present writer and found to be as described by Billings. The accessory interbrachial plates, though somewhat irregular in development in different areas in the type species of Petraster, are normal in position and a similar but more complete development also appears in Lindstrémaster and Palasterina.
Petraster is distinguished from Palasterina as follows: The most important feature is that the inframarginal plates of the former are prominent, closely adjoining and short but wide, while in Palas- terina they are small, not conspicuous, and globular, or subquadrate. The next important difference is on the abactinal disk, where in Palasterina there is an irregular ring of prominent basal radial, and supramarginal plates. These are absent in Petraster. The acces- sory interbrachial ossicles in the latter genus never attain the distal region of the rays as in Palasterina where these pieces are also more numerous. Palasterina is also more abundantly spinose than Petraster.
Schuchertia has no inframarginals as marginal plates, which at once distinguishes it from both Petraster and Palasterina. It is true that in Schuchertia inframarginals are also present but they are usually not well developed and remain adjoining the adambulacrals. These two columns are therefore not separated from one another by accessory interbrachial plates as in Petraster and Palasterina.
The primary structure of Petraster is that of Hudsonaster. So many of the generic characters are common to both that the former genus appears almost certainly to have been derived through the latter. It is true that the central abactinal area of the disk in Petraster is devoid of the large basal plates, a marked character in Hudsonaster, but the other generic characters are all present in the former. Petras- ter adds more or less numerous columns of radial accessory ambital and accessory interbrachial plates, none of which are present in Hudsonaster. It is these accessory ossicles which differentiate these
REVISION OF PALEOZOIC STELLEROIDEA. 141
genera and show the line of development from the deeply stellate primary form to the pentagonal genera with well-developed inter- brachial arcs.
PETRASTER RIGIDUS (Billings).
Plate 27, fig. 5.
Palasterina rigidus Brutineas, Geol. Surv. Canada, Rep. of Progress, 1853-1856, 1857, p. 291.
Petraster rigidus Brturnas, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 80, pl. 10, fig. 3a (not fig. 3b5=Hudsonaster matutinus)—Wricaut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 29.—HALL, iranian Rep. N. Y. State Cab. Nat. Hist., 1868, p. 294; rev. ed., 1868=1870, p. 337.
Description of 1858.— This species has much the aspect of an Astropecten; the disk is one-fourth the whole diameter, the rays rather slender and uniformly tapering, the angles between the bases of the rays rounded. The plates fof the actinal side] which appear to be adambulacral [increase very little in size from the tips of the rays toward the mouth], are quadrate and a little convex; [the adambula- cral columns terminated in the mouth area by a pair of pointed oral plates and not by a single plate as shown in the original illustra- tion], the marginal [inframarginal] plates oblong, and also convex [certainly not less than 16 and probably 20 in each column, increasing rapidly in size toward the axils, where there is a single large axillary plate]; the disk plates [accessory interbrachials] consist of three at each angle [one orally and two distally], and a single row [of not more than seven plates] on each side of the ray, but extending only one- third or one-half of the length of the ray; they all lie between the [infra] marginal and adambulacral plates. [Abactinal side unknown.] The specimen figured was about 2 inches [or 50 mm.] in diameter when perfect; width of disk half an inch, and of rays at the base about three lines.”
Formation and locality—Trenton limestone, Ottawa, Canada. Holotype No. 1401a is in the Victoria Memorial Museum, Ottawa. The species has also been identified by Springer in the Lower Trenton (Kirkfield) at Kirkfield, Ontario.
Remarks.—Hall and Billings discussed their asterid genera and species at different times and finally the former examined Billings’s material. In this connection Hall showed that figure 36 of Petraster rigidus was based on the actinal side of Hudsonaster matutinus. Regarding figure 3a, which is the holotype of this species, he in 1870 wrote as follows:
“The specimen illustrated in figure 3a has a few small intercalated plates between the marginal and ambulacral [adambulacral] ranges in two of the axils of the rays, and there are a smaller number of gran- ules in a similar position but unequally distributed on one side of
142 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
another axil, while two of the axils do not show any such intercalated plates or granules. In one of the rays, at least, the ambulacral, adam- bulacral, and marginal plates are distinctly visible, without inter- calated plates on either side.
“The presence of these unequally distributed plates or granules is apparently an abnormal structure, probably the result of accident during the growth of the animal; and this view is sustained by the fact that the other parts have the ordinary structure of Palzaster, and in all other respects the specimen agrees with the typical Palz- aster matutina.”’
The holotype was examined by the writer and although imperfect was found to have a normal development, with the plates in their proper places in at least two of the rays and axils. It certainly is not an abnormal development of ‘‘ Palzaster matutina”’ but represents a normal individual of a distinct genus and species diverging from Hudsonaster matutinus toward the forms with large disks and great axillary areas, as in Lindstrémaster and Palasterina. Hall seemingly was led to make the erroneous remarks above quoted through the fact that Billings had also included in his description and illustration (36) an individual of Hudsonaster matutinus, an error due to the undoubtedly close relationship of this form with Petraster rigidus.
PETRASTER SPECIOSUS (Miller and Dyer).
Plate 23, figs. 5-7; plate 26, fig. 1; plate 27, figs. 1-4.
Palzasterina speciosa MitteR and Dyer, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 30, pl. 1, fig. 7—MuttEr, N. Amer. Geol. Pal., 1889, p. 266, fig. 381.
Palxasterina approzimata MittER and Dyer, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 30, pl. 1, fig. 8,
Original description of Palxasterina speciosa.—‘ Pentagonal; rays obtuse at their apices; greatest distance from pomt to pomt about 24 inches; breadth of body between rays about 14 inches, and dis- tance from tip of ray to next adjoming tip on either side about 1} inches.
“The [infra] marginal plates are small and somewhat hemispher- - ical near the termination of the rays, they gradually enlarge and become square, and then rectangular as they approach the disk, until at the narrowest part of the disk or body of the fossil they are twice as long as wide. There are about 50 marginal plates between the apex of one ray and the next one adjoining, or, in a perfect specimen of this size, about 250.
“The back or dorsal side is covered with numerous plates (prob- ably in a complete specimen of this size there would be 1,000 or more), which are very prominent in the center or somewhat conical, and seem to have been joined together with deeply serrated edges. The plates have from three to eight of these indentations, which, give them a beautiful starlike appearance.
REVISION OF PALEOZOIC STELLEROIDEA. i435
“The ambulacral grooves are narrow and deep, as shown by the -sharp ridges on the back of the specimen. The small dorsal plates which cover the ambulacral pieces are exfoliated in some places, and show two rows of ambulacral plates coming evenly together and forming the sharp ridge.’’
Original description of Palxasterina approximata.—‘ Pentagonal; rays more slender than in P. speciosa; greatest distance from point - to point in the specimen figured 1.15 inches and breadth of the body one-half inch; another specimen from the collection of Mrs. M. P. Haines, of Richmond, Ind., measures from point to point 2.5 inches, and has a breadth of body of nine-tenths inch.
‘The [infra] marginal plates have about the same form, and are about as numerous as they are in P. speciosa. The adambulacral plates are arranged with their length across the rays. The oral plates are very prominent. [This statement is somewhat in error. The five prominent points around the mouth are each formed of one large interbrachial plate and a pair of proximal adambulacrals.] The space between the [infra] marginal plates and the oral ones [adambu- lacrals] is filled with numerous small [accessory interbrachial] pieces. The ambulacral grooves are narrow. Ambulacral ossicles unknown.
‘“The dorsal side is covered with small conical pieces, which give it a coarsely granular appearance. The madreporiform tubercle is prominent, conical, and longitudinally striated.
‘This species is distinguished from P. speciosa by its narrower rays, more contracted body, and smaller dorsal plates.”
Emended description—The holotype of P. speciosa measures: R=33mm.,r=18mm. The holotype of P. approximata measures: R= 15 mm., r= 6.5 mm.
Rays in young specimens slender distally, but with age they become obtuse and very wide proximally and here merge into the large disk. Interbrachial arcs very large.
The abactinal area of disk and rays is bounded by columns of very prominent inframarginal plates. Beginning at the apex of each ray they are very small and globular, soon they become quadrate and gradually shorter but wider, so that near the middle of each interbra- chial arc they have a crowded appearance. In a full-grown specimen there are about 50 and in a half-grown example about 45 of these plates between the distal ends of adjoining rays. In the distal region these plates are rounded and nearly smooth but gradually become granular and strongly convex, each with one prominent point for an articulating spine, none of which, however, have been observed. On the actinal side these inframarginals are also very prominent and pustulose but here are flat. They are most prominent near the center of the interbrachial arcs.
50601°—Bull. 88—15——10
144 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
The supramarginal columns begin at the very apex of the rays and for more than one-third of their length adjoin the inframarginals where ambital plates begin to appear. The supramarginal columns are continuous over the disk in a broad curve, with about 18 to 20 in a column, or from apex to apex of adjoining rays there are from 35 to 40 of these plates. In the axillary areas they are separated ‘from the inframarginals by three or four rows of ambital plates. At the apex of the rays the supramarginals are highly convex and nearly circular in outline but soon pass into more and more dis- tinctly stellate plates. This is the form of all the abactinal plates inside of the inframarginals; they are stellate, highly convex, each with a central node for an articulating spine and a few granules that are the bases for smaller spines.
Each radial column appears immediately beneath the two terminal or rather distal supramarginal plates and then continues as a column to near the center of the disk. They are more prominent than the other columns excepting the marginals and have not less than 25 plates in each one. On each side of the radials are five columns of radial accessory plates which appear to continue as columns over the disk in broad curves joining those of the next ray. Between these columns in the axillary areas are additional accessory plates. These columns of accessory plates appear singly, first on one side and later on the other, and not in pairs simultaneously, one on each side of the radial columns.
Ambital areas well developed in the axillary region, where there are about three columns of these plates. The columns pinch out rapidly distally and none are present in the outer third of the rays.
The plate arrangement of the central part of the disk can not be made out.
Madreporite of medium size, highly conical, and conspicuous, with numerous sharp single or bifureating ridges; on the under side are seen two outwardly directed spiral cones (the white lines of the drawing representing the spiral tubes in the madreporite), reminding one of the brachia in Atrypa (pl. 27, fig. 4).
Adambulacral plates depressed, convex, subquadrangular in out- line in young specimens, but in fully grown individuals a number of these in the central region of the column are much drawn out laterally and are here two or three times as wide as long. Jn a half-grown individual there are about 20 of these plates in a column, but in a mature specimen there appear to be not less than 26. These plates end inwardly in an apex, against which terminate the ridges of the ambulacral plates. The adambulacral and inframarginal columns are closely adjoining in the distal two-thirds of the rays but proxi-
REVISION OF PALEOZOIC STELLEROIDEA. 145
mally they are separated from each other by numerous accessory interbrachial plates, of which there appear to be not less than 30 in each area. The apexes of these interbrachial areas form the oral armature and each consists of two adambulacral plates, back of which is a rather large interbrachial plate.
Ambulacral grooves narrow, tapering, and deeply V-shaped. Ambulacral plates shghtly alternating, about as long as wide, and proximally superposed, with about 26 in each column. Each plate has an L-shaped ridge with the poimt proximally directed. The podial openings are situated in the outer proximal corner of the plates and between the inner angles of two adambulacrals.
Formation and locality—Richmond and Maysville formations of the Upper Ordovicic. The holotype of P. speciosa was found by Mr. W. C. Barnhart, on Twin Creek, near Winchester, in Preble County, Ohio, and is now in the Dyer collection of the Museum of Comparative Zoélogy, Harvard University (No. 14). Four other less well-preserved specimens are in the Harris collection of the United States National Museum and were found in the vicinity of Waynesville, Ohio. The holotype of P. approximata and another similar-sized specimen but not so well preserved are also from the vicinity of Waynesville, Ohio. The first is in the Dyer collection of the Museum of Comparative Zoédlogy (No. 15), and the other in the United States National Museum. There is a slab with two young individuals much etched with acid but otherwise excellent, showing the actinal side, in the Gurley collection of the University of Chicago (No. 10979). Finally there are two fine specimens, not fully grown, showing well the actinal and abactinal sides, in the Haines collection of the same university (Nos. 10839 and 10840), found near Hamilton, Ohio; these are apparently from the very top of the Maysville formation.
Remarks.—P. speciosa is described by Miller and Dyer from the abactinal side and P. approximata from the actinal side. These writers point out that the rays are more slender and the disk more contracted in the latter, but when one considers that it is less than half the size of the former and that during growth these forms con- tinually add accessory plates, this difference in form is seen to be one of growth. The ‘‘smaller dorsal plates’? noted by these writers in Mrs. Haines’s specimen of P. approximata are a character which the present writer does not regard as of value unless they be constant at this lower geologic horizon (Maysville at Hamilton), in which event this specimen can later on be distinguished by another specific name.
Cat. No. 60609, U.S.N.M.
146 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. PETRASTER (?) AMERICANUS (D’Orbigny).
Plate 26, fig. 2.
Asterias GRAHAM, ANTHONY, and James, Amer. Journ. Sci., ser. 2, vol. 1, 1846, p. 441, figure but no description.
Celaster americanus D’OrBi1GNY, Prodr. de Paleont., vol. 1, 1849, p. 22 (name proposed).
Asterias anthonii Dana, Manual Geol., ed. 1, 1863, p. 221, with figure but no description.
Palasterina (?) jamesi Dana, Amer. Journ. Sci., ser. 2, vol. 35, 1863, p. 295; Manual Geol., ed. 2, 1864, p. 221, with figure but no description.
Palzaster jamesi Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 286; rev. ed., 1868=1870, p. 329.—Mzrerx, Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 62, pl. 4, fig. 4.
Meek’s description.—‘‘Through the kindness of Mr. U. P. James, of Cincinnati, the discoverer of this fossil, I have now before me the original typical specimen, which I found not in a condition to be fully and systematically characterized, nor perhaps to afford the means of determining, beyond doubt, its generic affinities. It evidently attained a large size, and has a comparatively large disk, with its five rays rather broad at their inner ends, somewhat rapidly tapering, and apparently longer than the diameter of the disk. It evidently lies [does lie] in the matrix in such a manner as to show the ventral side [the inner dorsal aspect of the ventral plates], but pre- sents the appearance of having the marginal and disk plates of this side removed [they are present]. The five pairs of oral pieces [proxi- mal adambulacral plates] are seen in place, and proceeding outward from these can be seen a row of adambulacral pieces on each side of each of the rather wide [marrow] ambulacral furrows. These latter pieces are [proximally] nearly three times as long as their diameters in the direction of the length of the rays, and quite promi- nent at their inner ends, where they are articulated together by little processes and corresponding sockets or sinuses; while the outer two-thirds of each is flattened and distinctly more depressed than their inner ends. Outside of, and alternating with, the outer flat- tened ends of these adambulacral pieces, a row of [inframarginal] nearly square, or more or less oblong pieces, may be seen all along the margins of the rays, and connecting at their axilla in such a manner as to leave room for several disk [or interbrachial] plates between them and the oral and inner adambulacral pieces.”
In each interbrachial area there are inserted between the infra- marginals and adambulacrals interbrachial plates as follows: Proxi- mally one hexagonal plate upon which rest two similar plates mar- gined by the inframarginals.
“At some places within the [narrow] ambulacral furrows, remains of ambulacral ossicula can be seen deeply interlocking with the inner ends of the adambulacral pieces, but their exact form, and the
* REVISION OF PALEOZOIC STELLEROIDEA. 147
position and arrangement of the ambulacral pores, can not be clearly made out in the specimen studied.
‘The two oral pieces [proximal adambulacrals] of each of the five pairs are separated by deep sutures, and have an irregular form, bemg longer than wide, and, like the adambulacral pieces, which they somewhat exceed im size, flattened and depressed at their outer ends, and elevated into crestlike prominences farther in, with a lateral process or thickening on the outer side of each, in which a more or less distinct pit may be seen.”’ Between the pairs of oral adam- bulacral plates are inserted small, single, subquadrangular plates, the proximal plate of each pair of ambulacral ossicles. Orad_ to each pair of oral armature plates are situated single hemispheric plates.
‘The surface, and the arrangement of the dorsal parts, are un- known; but they were probably armed with short spines, as some remains of little spines are seen in the matrix at the margin of the disk, at one place.
‘As the extremities of none of the rays can be clearly seen, the exact breadth of the whole fossil, between the ends of opposite rays, can not be exactly given, but it is evident that the length of one of the rays, measuring from the middle of the disk, must have been a little more than 2 inches, and consequently that the diam- eter across from the extremities of opposite rays could not be less than about 4 inches. The breadth of the disk is 1.20 inches; and that of the rays at their inner ends, 0.70 inch.”
Formation and locality—The single specimen was found in the Maysville formation (Ordovicic), by Mr. U. P. James, on or near Vine Street hill, Cincinnati, Ohio, and is now in the James collection of the Walker Museum of the University of Chicago.
Remarks.—This large species is quite distinct from any other star- fish in having three rows of interbrachial plates, one piece in the proxi- mal, two in the medial, and five or possibly more in the distal row. While the arrangement of these interbrachial plates is different than in the other species of Petraster, their position is that of this genus. Therefore this species is for the present referred to Petraster. The preservation of this specimen is such that its generic and spevific characters will remain in obscurity until other material is found. It lies with the actinal side buried in the limestone while all of the abactinal plates have been worn away. What one sees is therefore the inner or dorsal aspect of the ventral skeleton.
PETRASTER SMYTHI McCoy. Petraster smythi McCoy, Geol. Surv. Victoria, Prodr. Pal. Victoria, dec. J, 1874,
p. 41, pl. 10, figs. 1-16. Original description—‘‘Five broad semielliptical lobes meeting at slightly rounded reentering angles, leaving the length and the
148 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
width at base of the rays nearly equal and less than the width of the disk. The upper surface is covered with crowded irregularly polyg- onal tumid plates. Madreporiform tubercle very large (14 lmes in diameter), irregularly porous, and rugged with branching vermicular ridges, excentric toward base of the two posterior rays. Ambulacral groove very narrow, bordered with a row of large transversely oblong adambulacral plates, wider than long, about 6 im 2 lines at middle of ray; margin of the rays bordered with a rather smaller row of similar marginal plates; between the row of adambulacral and mar- ginal plates an intercalary row of small irregular plates. Width of disk between the rays, 7 lines; from tip to tip of rays, about 1 inch 2 lines; length of ray, about 54 lines.
‘‘Very rare in the fine sandy Upper Silurian rocks of Moonee Ponds, Flemington, a little north of Melbourne [Australia].’’
Remarks.—The holotype exposes the abactinal side, but the plates of two of the rays are absent, exposing the actinal skeleton, which is therefore seen from its inner side. So far as one can judge of the description and illustration, the species is a small but genuine Petras- ter. Abactinally the rays have conspicuous radial and supramar- ginal columns, each with about 17 ossicles, that are tumid and are all closely adjoming. Outside of these in the distal portion of the rays are the equally conspicuous inframarginals, and they margin not only these parts but the entire animal; proximally the inframar- ginals separate more and more from the supramarginals, forming small ambital areas, occupied by a number (can not be determined) of rounded plates that now appear not to have been closely adjoining.
Madreporite large, radiately striate, situated in an interradius and well inside the ambital area.
Ambulacralia large, about 12 in a column, and opposite one another. Adambulacrals smaller, about 14 inacolumn. Interbrachial struc- ture unknown.
Genus LINDSTROMASTER Gregory.
Lindstromaster Greaory, Geol. Mag., dec. 4, vol. 6, 1899, pp. 344, 346. Hisingeraster Srisrvz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 224, 225 (same genoholotype as for Lindstrémaster).
Original description —‘‘Paleeasterinide with flat pentagonal disk and five short blunt rays.
“The plates of the disk are large, polygonal, tuberculate, and crowded into a close tessellate pavement, which completely covers the interradial areas.
REVISION OF PALEOZOIC STELLEROIDEBA. 149
‘Marginal [inframarginal] plates well developed and conspicuous, and but slightly smaller than the adambulacrals. Both supra- and inframarginals appear to be present.
‘The abactinal [actinal] furrows are large and subpetaloid.” They are bounded by large tuberculate adambulacral plates. The ambu- lacral plates are boot-shaped [and slightly alternating]. The pores for the podia are large, and. occur on the suture between the adam- bulacrals and ambulacrals.
‘“The adambulacral elements in the oral armature are prominent, and consist of five pairs of subtriangular plates.
‘““Type-species: Asterias antiqua, Hisinger 1837. Silurian: Got- land.’’ No other species of this genus is known.
Remarks.—Of this genus only the actinal side is known and the published figure from a drawing by Mr. George Lilejevall is one of the best of Paleozoic starfishes. Lindstrémaster differs from Petras- ter in but one generic character, if it be a generic one, in that the ambulacral furrows are large and subpetaloid in the former and narrow and slowly tapering in Petraster. However, since the abac- tinal area is unknown in Lindstrémaster there probably will be dis- covered in this area differences distinguishing it from Petraster. It is also probable that the marginals in Lindstrémaster which Gregory thinks are ‘‘both supra- and inframarginals’’ lying directly super- posed are only inframarginals. In Siluric starfishes these plates have not attained the superposed position so marked in recent genera. The supramarginais are here never true marginals and always he more or less inside the inframarginals, which are the true marginals of these early genera. For other remarks see Palxostella.
The name Hisingeraster was published after Gregory’s name and is based on the same genotype.
When more material is obtained and the genus is restudied, com- parisons should also be made with Palasterina primeva, as the two forms appear to have much in common.
LINDSTROMASTER ANTIQUUS (Hisinger).
Asterias antiqua Hisincer, Letheea Suecia, 1837, p. 89, pl. 26, fig. 6.
Lindstromaster antiqua Greaory, Geol. Mag., dec. 4, vol. 6, 1899, pp. 348, 347, pl. 16, figs, la, 1b (complete synonymy given here).—Scu6nporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 225.
A single specimen is known from ‘‘Bed C,’’ Mount Hoburg, Got- land, corresponding to the Wenlock of England. It is in the Angelin collection of the Mineralogical Museum at Copenhagen.
iw 0) BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genus PALASTERINA McCoy.
Palasterina McCoy, British Pal. Foss., 1851, p. 59 (mot defined).—Satter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, pp. 324, 327.—Bitune@s (part), Geol. Surv. Canada, Can, Org. Rem., dec. 3, 1858, p. 76.—Zrrren, Handb. Pal., vol, 1, 1879, p. 453.—Srtrrz (part), Palzeontographica, vol. 36, 1890, p. 226; (part), Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 43, 60.— Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 220.
Palxasterina Greeory, Geol. Mag., dec. 4, vol. 6, 1899, p. 349 (complete synonymy here).
The term Palasterina was used by McCoy in the following words: “‘Before I was aware Prof. Forbes had described them [the three species named below] it seemed to me that the U [rasterella] ruthveni and U. hirudo, as well as the similar American species, might be easily separated from the great starfishes forming the recent genus Uraster, by their small size and much more simple skeletons, and I had named the genus Urasterella in my manuscript. The U. primevus I thought generically distinct from the other two, as the rays were not contracted at base, etc.; and I had named it Palasterina, from its resemblance to the recent genus Asterina.”
The three species mentioned by McCoy had been described by him in manuscript, but on learning that descriptions had been previously published by Forbes, the former, in his ‘‘British Palzeozoic Fossils,”’ adopted the names of Salter. In writing of these three forms, as above quoted, he uses the generic name Palasterina (not Palzasterina, the generally accepted form), and while a type-species is selected, yet McCoy did not point out a single generic character of present value. His statement that ‘‘the rays were not contracted at base” is a feature which at that time distinguished Palasterina from Urasterella, but now many Paleozoic genera are known having rays ‘‘not con- tracted at base.”
While McCoy does not strictly propose the generic name, Salter is the first to accept and define Palasterina, which he does in the following words:
‘‘Pentagonal, depressed, the arms a little produced, with three or five principal rows of tubercles above, combined with a plated disk which fills up the angles; ambulacra rather shallow, of subquadrate or slightly transverse ossicles, bordered by a single row of squarish large plates, the lowest of which (ad-oral adambulacral plates, Huxley; angle-ossicula, Forbes) are large and triangular, bearing combs of spines (Upper Silurian).”’ .
Recently Gregory, in a paper entitled ‘‘On Lindstromaster and the classification of the Palzasterids”’ (1899), redefines the genus, basing his definition largely on P. bonneyi. In this connection he writes:
‘“The species [P. bonney?] is of interest, as the structure is better preserved than in the type of the genus [P. primzva], and thus we are
REVISION OF PALEOZOIC STELLEROIDEFA. 151
largely dependent upon it for our knowledge of the generic charac- ters’”’ (p. 350).
Emended description.—Disk large, with moderately developed inter- brachial arches. Rays five, short, and tapering more or less rapidly. ‘“‘R about twice as great as r.”
Abactinal area of rays distally with one medial column of large, thick, and subquadrangular radial plates, on each side of which are similar columns of supramarginal and inframarginal pieces. In this region the columns adjom and the ossicles are crowded, but proximally between the radial and supramarginal and between the latter and the inframarginal columns (ambital areas) are inserted numerous accessory smaller plates. The latter are most numerous in the ambital areas and at the base of the rays. The ossicles are packed into a tessellate pavement. In the center of the disk there seems to be a prominent central disk piece and at the bases of the rays there is a somewhat disconnected ring of ten most prominent plates, the five basal pieces of the radial and five interradial that give rise to the ten supramarginal columns. Inside of this ring there are probably numerous, very small pieces with no definite arrange- ment. A number of the proximal plates of both the radial and supramarginal columns may be separated from one another by small accessory pieces.
Madreporite abactinal.
Inframarginal plates bounding the entire outer edge and common to both sides of the animal. These plates are, however, small (smaller than the adambulacrals) and bear tufts of small spines.
Adambulacrals subquadrangular, and closely adjoining, each plate bearing on its outer lateral edge a tuft of three spines. Oral armature consists of five pairs of triangular adambulacral plates which have slender spines on the inner edges.
Interbrachial areas extending to near the distal ends of rays and occupied by numerous “‘isolated rounded or subangular [accessory interbrachial] plates bearing [single] small spines.”
Ambulacrals slightly alternating and about as numerous as the adambulacrals. Each plate has an L-shaped ridge, posteriorly directed. The podial openings are on the sutures between the ambulacrals and adambulacrals.
Genoholotype.— Uraster primevus Forbes. The above diagnosis is, however, based largely upon Palasterina bonneyi Gregory. Dr. Bather sent the writer a number of wax squeezes of the genoholo- type, and while the parts preserved are clear and sharp, yet the speci- mens are not complete enough to work out the generic characters. Therefore, for the present, P. bonney? is taken as the genoholotype.
Distribution —Ludlow shales (Upper Siluric) of Great Britain.
152 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Contains: P. primexva (Forbes). Ludlow of England. P. bonneyi Gregory. Ludlow of England. P. (2) ramseyensis Hicks. Tremadoc of Wales.
For other remarks see Palzostella.
Since the foregoing was written, Schéndorf’s work cited above has come to hand. He studied wax squeezes of P. primeva and deter- mined that the genotype is devoid of marginalia, and therefore refers Palasterina to the Cryptozonia. He writes: ‘‘Special marginalia ap- pear not to be present, at least the marginal rows are in no way dis- tinguishable from the other intermediary [accessory interbrachial] plates. Accordingly Palasterina primeva Forbes sp. does not belong as stated by Gregory (p. 349) to the asterids with distinct marginal plates, the Phanerozonia, but with the asterids having inconspicuous or no marginalia, the Cryptozonia”’ (p. 222).
The present writer holds that there are inframarginalia present all along the edge of the interbrachial areas and the rays, and that they are most typical along the distal portion of the rays. Here the inframarginalia are ontogenetically youngest and less affected by- subsequent growth displacement and alteration than are the older ones in the interbrachial areas. In the latter region it is true that the marginalia are not conspicuous, but so long as one can make them out to be inframarginalia, size alone can not be the criterion that will permit of the conclusion that no marginalia are present in Palasterina. Wowever, the difference in interpretation between Schéndorf and the writer is not a great one, as neither lays great taxonomic value on whether the marginalia are prominent or ‘‘not prominently developed” (p. 223). So long as the inframarginalia are more or less prominent, one of the generic characters of Palasterina, a phanerozonian, is present, and when they are so inconspicuous as not to be made out among the other ossicles, we have one of the generic characters of Schuchertia, a cryptozonian.
Schondorf also states that the arbalacre lias and the adambulacralia as well, are all opposite and do not alternate with one another. The present writer states that the ambulacrals are ‘‘slightly alternating,” , and throughout this work he has given the arrangement of these ossicles his special attention. In a great many cases, and especially in the Ordovicie species, he has had difficulty in ascertaining what was their actual position in the living animals, for nearly all the fossils have been squeezed more or less. He has always given their arrangement as they impressed him in the fossil when no evident dis- tortion could be seen. The writer would not lay special stress upon slight alternation among the ambulacralia, for in many Ordovicic species there is some variation in each ray from opposite to slightly , alternate. Of course, when the alternation or opposite arrangement
REVISION OF PALEOZOIC STELLEROIDEA. 153
is complete and fixed throughout the rays, he would lay great value on the character. It may be said that in the earliest Asteroidea the chronogenetic tendency is from slight alternation to complete and fixed opposite arrangement among the ambulacral ossicles.
PALASTERINA PRIMVA (Forbes).
Uraster primevus Forses, Mem. Geol. Surv. Great Britain, vol. 2, pt. 2, 1848, p. 463; Mem. Geol. Surv. United Kingdom, dec. 1, 1849, p. 2, pl. 1, figs. 2a, 2b; in McCoy, Brit. Pal. Foss., 1851, p. 60.—Murcuison, Siluria, 1854, p. 221, fig. 39.
Palasterina primxvus McCoy, Brit. Pal. Foss., 1851, p. 59 (nomen nudum).— Satter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 327, pl. 9, figs. 2a-2¢.— Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, p. 26, fig. 16a.—QueENsteED, Petrefactenkunde Deutsch- lands, vol. 4, 1876, p. 74, pl. 92, fig. 35.—Srtrrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 44; vol. 56, 1900, pp. 214, 224.—Scudnvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 220.
Palzasterina primxva GRecory, Geol. Mag., dec. 4, vol. 6, 1899, p. 349.—SpEn- cER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontogr. Soc. for 1913), 1914, pp. 37, 38, fig. 30.
Formation and locality —A common species in the Ludlow rocks. Underbarrow, Kendal, Westmoreland, and Leintwardine, Shropshire, England.
Remarks.—Dr. Bather furnished the author with wax squeezes of specimens Nos. £4990-E4993 (E61 is quite another species and abactinally more closely related to Hudsonaster) in the British Museum (Natural History). They are from the Lower Ludlow at Kendal, Westmoreland. These show little of value abactinally, but actinally are well preserved along the ambulacra. Unfortunately, however, none of the marginals are present and but little of the interbrachial areas. When better material is at hand a comparison should be made also with Lindstrémaster antiquus (Hisinger), as the two look suspiciously alike.
PALASTERINA BONNEYI Gregory.
Palzasterina bonneyi Grecory, Geol. Mag., dec. 4, vol. 6, 1899, pp. 349, 350, text figs. 1-3, and pl. 16, figs. 2a, 2b.—Scudnporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 223.
‘This species has hitherto been included in P. primeva, the type- species of the genus, from which it differs by having shorter and blunter rays, more numerous actinal interbrachial plates, and more adambulacral plates in each series; the character of the abactinal ray plates is also different in the species, the longitudinal series being widely separated at the proximal end of the rays in P. bonneyi”’ (Gregory).
Formation and locality——Ludlow shales. Leintwardine, Shrop- shire. Types in British Museum (Natural History).
154 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
PALASTERINA (?) RAMSEYENSIS Hicks. Palasterina ramseyensis Hicks, Quart. Journ. Geol. Soc. London, vol. 29, 1878, p. 51, pl. 4, figs. 21-23—Woopwarp, Geol. Mag., dec. 2, vol. 1, 1874, p. 96:
This starfish needs to be restudied in the light of modern knowl- edge. The specimens represented by Hicks’s figures 21 and 22 seem to be referable to Petraster rather than to Palasterina, while that of figure 23 appears to be nearer Mesopalezaster.
Formation and locality.—Said to be from the Tremadoe, but the development of the starfish seems to be in harmony with Upper Ordovicic time. The specimens are from Ramsey Island and St. Davids, Wales, and are in Mr. Lightbody’s collection.
Genus URANASTER Gregory.
Uranaster Grecory, Geol. Mag., dec. 4, vol. 6, 1899, p.347.—Scu6nporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 225.
The name is ‘from Uranus, the grandfather of Pluto; the starfish resembles the living genus Plutonaster.”
Generic description —Animal deeply pentagonal, above medium size, with well-developed interbrachial arches, and five long slender rays.
Inframarginal plates marginal, large, and elongated in the direction of the rays. These plates are apparently common to both the actinal and abactinal areas. Abactinally adjoining the inframarginals is another column of large submarginal plates (?supramarginals) alternating with the former, and sometimes there are smaller acces- sory pieces between these columns in the angles of the plates. The rays have no medial or radial columns of prominent plates, but the entire space between the submarginal columns is occupied by numer- ous closely fitting, convex, or tubercular plates which are arranged in alternate transverse rows, each having from three to four pieces on each side of a ray.
Interbrachial accessory plates numerous, polygonal, and, according to Baily’s figure of U. kinahani, arranged in crescentic rows conforming to the shape of the disk margin. These plates do not appear to extend between the marginals and adambulacrals beyond the mid- length of the rays.
Adambulacral plates tubercular, subquadrangular in outline, and widest transversely in the medial third of the column.
Ambulacral furrows very narrow, deep, and tapering gradually. Ambulacral plates traversed by strong transverse ridges.
Madreporite unknown.
Genoholotype.—Palasterina kinahami Baily. Upper Ordovicic. A second species is U. elize Spencer, also from the Ordovicic of Great Britain.
Remarks.— Uranaster differs from FPetraster, Palasterina, and Lindstrémaster in having the abactinal area of the rays between the
REVISION OF PALEOZOIC STELLEROIDEA. 155
two pairs of marginal columns filled with small tuberculate plates arranged in transverse rows. The other genera have the plates in longitudinal columns. URANASTER KINAHANI (Baily). Palasterina kinahanit Batty, in Kinanan, Man. Geol. Ireland, 1878, pp. xv, 26, pl. 2, fig. 1; Mem. Geol. Surv. Ireland, Expl. Mem. Sheets Nos. 169, 170, 180, 181, 1879, pp. 58, 59, fig. 6. Cranaster kinahani Greaory, Geol. Mag., dec. 4, vol. 6, 1899, p. 348.—Scué Nporr, Jahrb. nassauisch, Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 225.
This species occurs abundantly as natural molds in the Caradoc (Upper Ordovicic), near Ballymadder Point and Bannow, Wexford, Ireland. A specimen is in the British Museum (Natural History), No. E 194.
URANASTER ELIZ Spencer.
Uranaster elize SpENcER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pp. 18, 20, 23, figs. 18, 23.
From the Ordovicic of Great Britain.
Genus PALAAOSTELLA Stiirtz. Palzostella Stiintz, Paleeontographica, vol. 36, 1890, p. 230, pl. 31, figs. 42, 43;
)
Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 42, 58, pl. 1, figs.5-8, Palenectria Stirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893. p- 12 (genoholotype the second specimen of Palxostella solida).
Description.—Animal attaining a large size, with large pentagonal interbrachial arcs. Rays five, stout. Ambulacral grooves wide and apparently regularly tapering.
Abactinally the inframarginals are also the marginals for this area. Near the distal ends of the rays the supramarginals adjoin and lie either partially over or inside of the inframarginals and continue nearly to the axille. There also seems to be a single radial column, confined, however, to the distal third of the rays. Other- wise the abactinal skeleton consists of very numerous, small, irregu- larly shaped, loosely interlocking plates without definite arrangement.
Madreporite abactinal.
Actinally the animal is bounded by subquadrate, numerously spine-bearing, inframarginal plates which increase rapidly in size towards the axille, where they are ponderous and nearly twice as wide as long. Ambulacral plates alternating, L-shaped, with single columns of podial openings. Adambulacrals subquadrate, prominent, increasing regularly in width proximally and bearing spines like the marginals. Interbrachial areas large, reaching to near the distal ends of rays, widely separating the inframarginals from the adambulacrals in the axillary region, and the space occupied by very numerous, small, spine-bearing, apparently irregularly dis- posed plates. :
156 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genoholotype and only species—P. solida Stiirtz. Two speci- mens are known from the Lower Devonic roofing slates, Bundenbach, Germany.
Remarks.—The starfishes from the Bundenbach roofing slates are at best but poor fossils and were it not for the great skill of Mr. Stiirtz in cleaning them out of the matrix their systematic position could not well be determined. At best they are compressed to almost paper thickness and distorted during solidification and shortening or elongation of the slates. Under these circumstances it appears best to redescribe the detailed abactinal characters as given by Stiirtz.. He mentions numerous paxille and finds many characters common to both Palzostella and the living Nectria.
Paleostella is closely related to Palasterina, also to Lindstrémaster, and may be a descendant of the latter. The actinal structure in Lindstrémaster and Paleostella is nearly alike, both having large inframarginals and adambulacrals, but the interbrachial areas in the former are occupied by large closely adjoining plates, while in the latter these are small and somewhat loosely interlocking. Abac- tinally they can not be compared, since that side is unknown in Lindstrémaster. The greatest difference between Palasterina and Palzostella is that the former has small inframarginals while in the latter they are very large. Then the supramarginal and radial columns in Palasterina are better developed and comparatively larger, while in Palzostella they are shorter and most prominent in the distal half of the rays. In the latter genus the central region of the disk has no ring of fifteen basal radial and supramarginal plates as in Palasterina.
From this evidence it seems probable that the line of descent is from Petraster to Lindstrémaster to Palxostella in maintaining promi- nent columns of inframarginals, while the line from Petraster to Palasterina tends toward the reduction or elimination of these plates as a conspicuous skeleton element.
Palznectria is based on the second specimen, and the genus is described as follows: ‘‘Should the described starfish [the second specimen of Palzxostella solida Stiirtz] prove not to be identical with Palzostella, which is possible, even though not probable—the other specimen is in the British Museum—TI propose for it the new name Palznectria devonica.’’ Unless the author takes the time to work out his new forms, or decides the problem presented for himself, he should not expect some one else to do this for him. Under these circumstances the genus and species are regarded as not defined.
Genus PSEUDOPALASTERINA Sturtz.
Pseudopalasterina Stiirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 219, 224.
Genoholotype and only species.—Palasterina follmanni Stiirtz.
REVISION OF PALEOZOIC STELLEROIDEA. 157
PSEUDOPALASTERINA FOLLMANNI (Stiirtz).
Palasterina follmanni Srirrz, Paleontographica, vol. 36, 1890, p. 226, pl. 29, figs. 29-31a.
Pseudopalasterina follmanni Stiirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 219, 224.
Actinally this species has ambulacrals and narrow adambulacrals and outside of the latter the interbrachial and abactinal areas consist of a membrane with small spine-bearing plates. It has no inframar- ginal nor radial and supramarginal columns, features characterizing Palasterina.
Formation and locality.—Lower Devonic of Bundenbach, Germany.
NEW GENUS.
NEW SPECIES.
Prof. Weller got on Fountain Creek, at Waterloo, Tlinois, in the St. Louis limestone, a small pentagonal asterid (No. 14396, Univer- sity of Chicago collection) showing only the actinal side, that differs from all other known forms of the large-disked genera. The fiye rays are completely within the pentagon, with the interbrachial areas large and straight-sided. These areas are made up of a few large tesselate plates, of which it seems that seven compose the interbrachial mar- gins and inside these there seem to be transverse rows, each with five, three, two, and one ossicles. It could not be made out whether the inframarginals and supramarginals are directly superposed, but this may be so.
Ambulacral furrows exceedingly narrow, a mere line. These are bounded by columns of large, very ornate adambulacrals, each with seven ossicles. Those of opposite columns alternate decidedly with one another and on its outer side each bears two short but dis- tinct spines.
Adambulacral oral armature in five very prominent pairs of pieces, long and pointed, and about twice as long as any other adambulacrals.
Measurements: R=8.5 mm., r=7 mm.
Family LEPIDASTERID Gregory (emend.).
Lepidasteride GREGORY (part), Geol. Mag., dec. 4, vol. 6, 1899, p. 352 (includes Lepidaster and Etheridgaster); Treat. Zool., vol.3, Echinoderma, 1900, p. 255.
Helianthasterine Grecory, Geol. Mag., dec. 4, vol. 6, 1899, p. 258.
Helianthasteride Svirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 204.—Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Primitive multi-rayed Phanerozonia apparently with the general structure of Paleasteride, but with as many as 24rays. Madreporite known only in Helianthaster, where it is interbrachial and on the
158 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
edge of the disk, more actinal than abactinal. Inframarginals or supramarginals bounding the rays.
Contains:
Lepidaster Forbes. Helianthaster Roemer. Lepidasterella, new genus.
Remarks.—For a discussion as to why there are multi-rayed—that is, more than the normal five-rayed—asterids, see the family Pale- osolasteride.
Genus LEPIDASTER Forbes.
Lepidaster Forpes, Mem. Geol. Surv. United Kingdom, British Org. Rem., dec. 3, 1850, p. 1, pl. 1, figs. 1-3.—Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p.35.—Woopwarp, Geol. Mag., dec. 2, vol. 1, 1874, p. 9—Zrrret, Handb. Pal., vol. 1, 1879, p. 454.—Stirrz, Paleontographica, vol. 36, 1890, p. 222, pl. 28, figs.19-20; Verh, naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 52, 72.
Generic description.—Disk very large, over 50 mm. in diameter, and apparently composed of heavy, closely set, polygonal plates. Rays 13 in number, fairly stout, not slender, and tapering fairly rapidly in the distal half. R=52mm.,r=25mm. A little more than half the length of the rays extends beyond the disk.
Actinally, the rays are bounded on each side of the very narrow ambulacral furrow by two columns of strong, tumid, closely ad- joining, transversely oblong, adambulacral and inframarginal plates. The latter are also the marginals for the abactinal side. The adam- bulacrals are tuberculate and probably bore small spines; there are 25 ossicles in each column. Ambulacrals unknown, but the arrangement of the adambulacrals indicates that they were slightly alternate.
Madreporite and interbrachial areas unknown.
Abactinally little is known. The rays are described as having ‘numerous small polygonal nearly flat ossicula, closely set, and of various sizes.” To judge by similar rays in other genera, it would appear that Lepidaster may have had radial and supramarginal columns of ossicles.
Genoholotype and only species —L. grayi Forbes. The holotype was found in the quarries of Wenlock limestone in the Castle Hill at Dudley, England.
Observations.—Forbes’s illustration leads the writer to believe that the abactinal plates have been deranged and that originally the larger pieces were arranged in supramarginal columns, while the smaller ones composed the radial row of ossicula. This type of structure generally goes with the actinal arrangement as here seen in Lepidaster, a duplicate of the same structure in Hudsonaster, Palz- aster, and Mesopaleaster. Stiirtz compares the abactinal skeleton of
REVISION OF PALEOZOIC STELLEROIDEA. 159
Lepidaster with the recent Scythaster, which is made up of plates of various sizes without regular arrangement. It seems more natural to compare Lepidaster with Siluric and Ordovicic genera than with recent forms, and particularly when nearly identical structures are found in the genera mentioned.
Forbes also describes Lepidaster as having the ambulacral grooves “towards the extremity, in some instances partially filled up by small polygonal intervening plates.” His figures show a few of these plates arranged in single columns. This anomalous structure is undoubtedly best explained by accepting Stiirtz’s conclusion, that they are the separated ambulacral pieces, since otherwise none of these plates appear to be present. As a fifth actinal, or a single ambulacral column, the structure is out of all harmony with star- fishes.
Genus HELIANTHASTER Roemer.
Helianthaster ROEMER, Palzontographica, vol. 9, 1863, p. 147, pl. 28.—QUENSTEDT, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 82, pl. 93, fig. 32.—Zrrren, Handb. Pal., vol. 1, 1879, p. 453.—Srirrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 148; Paleontographica, vol. 32, 1886, p.81; vol. 36, 1890, p. 218, pl. 27; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 12, 30.—Grecory, Treat. Zool., vol. 3, Echinoderma, 1900, p. 258.—CLarKgE, Bull. N. Y. State Mus., No. 121, 1908, p. 61, pl. 10.—Scuénporr, Jahrb. nas- sauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 34.
Generic characters.—Disk large; rays 14 to 16 in the genotype. Interbrachial actinal areas well developed but not over-large for a many-rayed asterid, either integumentary or granular, distally con- cavely cut out and margined by several small inframarginals, about seven on each side of a larger axillary piece.
Madreporite marginal, large, more actinal than abactinal, radi- ately striate, interbrachial, and situated immediately outside of the inframarginals. In the fossils it appears to be of the actinal surface.
Rays long and slender, protruding beyond the disk more than twice the length inside the disk. Adambulacrals opposite one another, with smali lateral spines, prominent and large, wider than long, bounding the rays, and terminating proximally in pairs of modified pieces. These make the adambulacral parts of the oral armature. Ambulacral grooves narrow, ambulacral ossicles not seen but probably arranged opposite one another.
Abactinally the disk appears to have a scalo-like covering. The rays have median columns of radialia, outside of which are stout columns of supramarginal ossicles.
Genoholotype (type by monotypy).—H. rhenanus Roemer (citations as above). Lower Devonic of Bundenbach, Germany. The above definition is based on the illustrations of Stiirtz. There is a second species in Germany, and H. filiciformis occurs in England.
50601°—Bull. 88—15——11
160 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. HELIANTHASTER FILICIFORMIS Woodward.
Helianthaster filiciformis Woopwarp, Geol. Mag., dec. 2, vol. 1, 1874, pp. 7-10, fig. on p. 8.
A natural mold in sandstone measuring about 45 mm. in total diameter. Has 11 rays. The disk ‘must have measured 10 mim. in breadth. The arms are 17 mm. in length, and near their junction with the body are 5 mm. broad.’ The specimen needs to - be restudied and modernized.
The holotype is from the Upper Devonic at Great Inglebourne, Harberton, South Devon, England, and is now in the collection of Mr. Champernowne.
LEPIDASTERELLA, new genus. Plate 25, fig. 2.
Lepidasterella ScHucueErt, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 23.
Much like Lepidaster, but with 24 rays instead of 13 as in that genus. Rays extending considerably beyond the disk. The abac- tinal side only is known, but it shows that the rays have slender radial columns, the ossicles of which are disposed alternatingly with the larger and more prominent supramarginals.. Outside of these in some rays may be seen the edges of the inframarginalia, and these have well developed but slender, rather long spines.
There appear to be no ambital areas, as the inframarginals of adjoining rays meet and at their junction begins the disk. The disk appears to have been made up of more or less closely adjoining polygonal plates whose arrangement is not discernible in the specimen.
The madreporite and its position are unknown.
Actinal area unknown.
Genoholotype and only species.—L. babcocki, new species.
Remarks.—The essential difference between Lepidaster and Legid- asterella is that the former has 13 rays while the latter has 24.
LEPIDASTERELLA BABCOCKI, new species. Plate 25, fig. 2.
Helianthaster, new species CLARKE, Fifty-ninth Rep. N.Y. State Mus., 1906, p. 37, and plate.
Helianthaster gyalum CuarKE (part), Bull. N. Y. State Mus., No. 121, 1908, p. 61 (not pls. 12, 13=Palxosolaster (?) gyalum).
Description.—Rays, 24. Length of best preserved ray in the holotype, 28 mm. Width of ray at base, 3 mm. Width of disk, probably not less than 20 mm.
Rays slender and regularly tapering. Their structure is only known abactinally, from a natural mold in a fine sandstone. Medi- ally there is a narrow but high column of radial plates, each one of
REVISION OF PALEOZOIC STELLEROIDEA. 161
which alternates with those of the supramarginal plates. The latter are slightly tumid, subquadrate in outline, regular in size, but decreasing gradually distally. Outside of these and margining the rays may be seen a little of the inframarginalia, which bear pairs of short, slender, and finely striated spines. There are from 31 to 33 closely adjoining plates in each one of the abactinal columns; there appear to be no accessory plates of any kind in the rays.
Disk circular in outline, somewhat tumid and covered by small many-sided plates that originally appear to have been closely adjoin- ing.
Remarks.—As this is the only American starfish with more than five rays, it is readily distinguished from all others. The abactinal arm structure is practically that of Hudsonaster, with the difference that in L. babcockt the inframarginals do not project beyond the supramarginals and are therefore not seen as a rule from the dorsal side in the natural casts.
Locality and formation.—The holotype, an excellent specimen, was found in the lower part of the Upper Devonic, near Ithaca, New York, by Mrs. G. W. Babcock, after whom the species is named; it is in her possession. The writer’s attention was called to this interesting specimen by Prof. H. S. Williams of Cornell University. Some years after this starfish was described in manuscript, Clarke directed attention as above cited to two others found in the Cashaqua shales of the Portage in Hunt’s quarry, at Interlaken, New York.
Cat. No. 60627 (cast), U.S.N.M.
FAMILY, unknown. Genus ASTROPECTEN Link.
The genus Astropecten is based upon living species, and it is not probable that the Devonic forms are identical. ASTROPECTEN (?) SCHLUTERI Startz. Astropecten schliitert Sturtz, Paleeontographica, vol. 32, 1886, p. 87, pl. 10, figs. 1, 1b, 2, 2a; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 51, 71. In the roofing slates of the Lower Devonic at Bundenbach, Ger- many. <A single very much distorted and compressed example is the basis of this species. Genus ATAXASTER Jaekel. Atazaster JAEKEL, Zeits. geol. Gesell., vol. 55,1903, Protokol, p. 14 (106). Genoholotype and only species —A. pygmeus Jackel. Ordovicic (D,), St. Benigna, Bohemia. Deseription.—* A small asterid whose ambulacrals in the distal parts are alternate, but in the proximal are opposite.”’ Remarks.—The above is all that is known about Atazaster, and for the present the genus has no value.
162 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. CRYPTOZONIA Sladen.
Specialized Asteroidea without true marginal plates. In other words, there are no large and conspicuous marginal plates bordering the animals, but in primitive forms large adambulacrals do margin the species. In other primitive forms more or less of the infra- marginals may be present, but if so they remain adjoining the adam- bulacrals.
Ambulacrals alternating or directly opposite one another.
Oral armature generally with the adambulacral elements the most conspicuous; more rarely the ambulacral elements are most promi- nent.
Contains the following families:
Stenasteride. Schuchertiide. Monasteride. Palasteriscida. Urasterellide. Schcenasteride. Calliasterellide. Paleosolasteride. Compsasteride.
Remarks.—This widely accepted order, which appears as if founded in nature on a single grand phylum, probably has no such value. In other words, asterids without either one or both of the marginal columns bounding the animal developed several times. Therefore, the absence of these ossicles is no indication of direct phyletic relationship, but such are simply cases of parallel development. As long as asterids retain the primitive characters of few columns of rather strong ossicles and the adambulacral type of oral armature, they are clearly Phanerozonia, but when the ponderous skeleton breaks up into a more flexible one of small pieces, then the marginal and abactinal columns vanish as such in the mass of small plates. On the other hand, ponderosity may even be retained with the loss of the inframarginals alone. In all of these Paleozoic forms, the adambulacral type of oral armature is the rule.
Among the Paleozoic ‘‘Cryptozonia’’ it seems certain that at least the families Stenasteridxe, Urasterellide, Schuchertiide, and Paleo- solasteridee had independent origins in Phanerozonia stocks. The Urasterellide and Calliasterellidze apparently had a single origin in the Phanerozonia subfamily Mesopaleasterine by the adoption of marked flexibility. On the other hand, the families Stenasteride and Monasteride retained rigidity and primitive characters, and more probably arose in the Hudsonasteride through the loss of the inframarginals alone. The Schuchertiidee also had their origin directly in some Phanerozonia stock and one naturally looks for it in forms developing large interbrachial areas as in the Palasterinide. In this family, however, the accessory plates are introduced between the adambulacrals and inframarginals, while in the former family they
REVISION OF PALEOZOIC STELLEROIDEA. 163
are introduced outside of the inframarginals and the entire abactinal skeleton is broken up into an abundance of tiny pieces. Therefore, one must go back for their origin at least as far as the Paleasteride. In this case it was not primarily flexibility that led to this supposed ordinal change, but it was due to increase of body cavity and enforced enlarging of the skeleton in the interbrachial and ambital areas, making the more or less pentagonal disk. It is probable that the Palasteriscide were their descendants, while the Scheenasteride may have been the final Paleozoic representatives of the same phyletic line. The Palzosolasteride seemingly arose in the Phancrozonia family Lepidasteride by the adoption of a flexible skeleton. It would, therefore, seem that the Paleozoic families of supposed Cryptozonia construction are to be grouped as follows: Superfamily Stenasteracea, new. Includes families Stenasteridse and Monasteride. Superfamily Urasterellacea, new. Includes families Urasterellidee, Calliasterellide, and Compsasteride. Superfamily Schuchertiacea, new. Includes families Schuchertiide, Palasteriscide, and Schoenasteride. Superfamily Paleeosolasteracea, new. Includes family Paleosolasteride.
STENASTERIDA, new family.
Rigid, small, primitive, five-rayed Cryptozonia, with rapidly taper- ing or petaloid rays. Ambulacrals few in number and opposite in arrangement. Interbrachial areas consisting of the single pairs of large basal adambulacral oral armature plates.
Abactinal skeleton unknown, but in some forms seemingly integu- mentary. No spines as yet known. It is probable that this family will be referred to the Auluroidea.
Contains:
Stenaster Billings. Tetraster Nicholson and Etheridge.
Genus STENASTER Billings (emend.). Plate 32, fig. 1.
Stenaster Brtuincs, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 77.— Stiirtz, Paleontographica, vol. 36, 1890, p. 220.—Grercaory, Geol. Mag., dec. 4, vol. 6, 1899, p. 352.—Srencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Palzontogr. Soc. for 1913), 1914, p. 22.
Urasterella Stiirtz (not McCoy), Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 40, 41, 56.
Generic characters.—Small rigid asterids, the largest example having R=20 mm., r=4.5 mm. Disk small, without interbrachial arcs. Rays five, short, stout, lanceolate or petaloid.
Abactinal area devoid of a preservable skeleton. For this reason when this side is at hand it is nearly always mistaken for the actinal, so nearly alike are the two.
164 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Madreporite unknown.
Adambulacral plates with granular-surfaces, few in number, never more than 17 in a column, subquadrangular and thick, greatest width about the middle of the rays, rapidly diminishing in size distally and making the margin of the rays and disk. The great proximal adam- bulacrals are the orals, occupying the axils in pairs, acutely triangular, more or less pointed, and terminating orally.
Ambulacral plates large, directly opposite one another and the adambulacrals as well, +-shaped, with the widest portion in the per- radial center of the rays; there are as many as 16 or 17 ambulacrals in a column. Laterally each plate is more or less excavated, both distally and proximally, thus leaving very large, subcircular podial openings.
Spines of any kind are so far unknown.
Genoholotype (the first species and the one selected by subsequent workers).—Stenaster salteri Billings.
Remarks.—This genus has not had a good standing, due largely to the fact that Palzaster Hall was poorly known when Billings described Stenaster and further because he included two distinct generic types in his genus. A careful reading of Stenaster, however, reveals that Billings actually based his genus on S. salteri, the first form following the generic description, and this selection has been followed since. Later on, McCoy applied the name Urasterella in a loose manner to the second species (Palzxaster pulchellus), and although it is a form of this genus it is not the genotype. Hall (1868) directed attention to this work of McCoy, but erroneously assumed that all of Stenaster was synonymous with Urasterella. It is true, as stated by Hall, that Billings’s second species is congeneric with Urasterella, but the first species and genotype is certainly quite dis- tinct from McCoy’s genus. Stiirtz (1890) also points out the same thing and gives a short and emended diagnosis of ‘“ Urasterella (Stenaster).”’ In 1893 the same writer applied McCoy’s name Urasterella to Stenaster salteri and made 8S. pulchellus the genotype of Urasterella, a proceeding that violates the rules of nomenclature.
Stenaster as here restricted differs from Urasterella in being more decidedly rigid and not so flexible as the latter, while the rays are far shorter and petaloid in form. For these reasons, Stenaster has comparatively few adambulacrals and ambulacrals, while there are many more of these ossicles in Urasterella. Finally, the former reveals no abactinal plates or spines of any kind, while the latter has a skeleton of small plates that terminate in long inarticulate spines or rods.
Actinally Stenaster is closely related to Tetraster, and the only marked difference is that the former has petaloid rays and more pronounced adambulacral oral jaws.
REVISION OF PALEOZOIC STELLEROIDEA. 165
There would be no need to point out here the difference between such distinct genera as Stenaster and Pailzaster were it not that Hall regarded the former as a synonym of the latter. In Stenaster the rays are petaloid and not slender and regularly tapering, as in Palzaster. The most marked distinction, however, is the fact that these two genera belong to different orders, for Palzaster has columns of inframarginals that are completely absent in Stenaster. Further, in the last-named genus, the interbrachial areas are made up each of two pairs of oral armature pieces, while in Palexaster there are, distally to these, additional large single axillary interbrachials.
Stenaster and the related genus Tetraster are very primitive in construction. Actinally they are seen to have the structure of Hudsonaster mimus the inframarginal columns and the single axillary interbrachials. It is this difference that makes the former genera members of the order Cryptozonia, while Hudsonaster is the most primitive of Phanerozonia. Until the abactinal area is known in Tetraster and Sienaster, positive phyletic relationship can not be stated, but in a number of specimens of the latter genus the evidence at hand indicates decided specialization through the complete removal of the heavily plated skeleton of Hudsonaster.
Distribution —Ordovicie of America. The following are the known species:
S. salteri Billings. Black River and Trenton.
S. (2) obtusus (Forbes). Bala of Ireland and Wales.
S. (?) coronella Salter). May Hillsandstone (Siluric) of England. S. (?) confluens Trautschold. Upper Carboniferous of Russia.
STENASTER SALTERI Billings. Plate 32, fig 1.
Stenaster salteri Brutinas, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 78, pl. 10, figs. la, 1b.—Wrreut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 28, fig. 15 (2) on p. 24.
Original description This species has rather short, broad rays, which are narrower where they are attached to the very contracted body than they are at about the center of their length. In conse- quence of this form, the sides of the rays are not parallel, but a little curved outward. As however only two specimens have been col- lected, and both appear to be a little flattened by vertical pressure, it may be that this leaflike shape of the rays is accidental [an abundance of specimens show this form to be the natural one]. * * * The adambulacral plates are oblong [granular and from 7 to 17 in each column in the smallest and largest examples], and the sutures between them are nearly at right angles to the ambu- lacral grooves; those next the body are a little sloping outward.
166 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Their length is about twice their breadth, and they are so disposed that the greater dimension is transverse or at right angles to the groove; the extremities which lie next to the grooves are angular, and some of them appear to have the contiguous pores partly exca- vated in them. The oral plates [adambulacrals] are acutely triangu- lar, the sharpest angle being toward the mouth [and form the inter- brachial areas]. The plates are smooth [the adambulacrals are all distinctly granular]. The ambulacral pores are very large, and the ossicles are much contracted in the middle and greatly expanded along the median line of the bottom of the groove.’’ These plates are directly opposite one another and the adambulacrals, and in number equal those of the latter.
The type-specimen figured by Billings measures: R=14 mm., r=3.5 mm., R=4r. Width of a ray at base about 4 mm., at about mid-length 5 mm. The largest specimen: R=20 mm., r=4.5 mm.
In the University of Toronto there is a specimen that in every way, except one, has the characters of Stenaster salteri. It was found associated with many other individuals at Kirkfield. It differs from its associates in having what appears to be a distinct disk, rather large, with concave sides, filling in the spaces between the rays. One looks in vain, however, for plates or spines, as the inter- brachial areas are nothing more than an amorphous mass of cal- cium carbonate. These areas are very distinct and stand out prom- inently, but because they do not reveal any plated or spiniferous struc- ture the writer regards them as false characters, produced during the permineralization of the specimen. This conclusion is further sup- ported by the fact that otherwise the characters are those of S. saltert.
Pormation and locality—Three specimens (the type, No. 1398, and two fragments) are from the Trenton limestone at Belleville, Ontario, and are now in the Museum of the Canadian Survey. Another specimen in that museum is on the same slab with Petraster rigidus and has been labeled Palzaster matutina. In Mr. Ulrich’s collection there are four isolated rays of this species obtained by him from the Black River limestone at Curdsville, Kentucky. A further specimen preserving two rays, from Government House Bay, Ottawa, was found by Mr. Walter R. Billings. In the Museum of Comparative Zodlogy there is still another individual which appears to be of this species; it was found by Mr. J. B. Perry at Panton, Vermont. Finally, an abundance of material was obtained in the Black River limestones at Kirkfield, Ontario; there are more than twenty specimens from this locality in the Walker collection of the University of Toronto, gathered by Mr. Townshend.
Cat. No. 60628, U.S.N.M.
REVISION OF PALEOZOIC STELLEROIDEA. 167 STENASTER (?) OBTUSUS (Forbes).
Asterias primxzva SAuTER and Sowersy, Quart. Jour. Geol. Soc. London, vol. 1, 1845, p. 8, 20 (table) (nomen nudum). Uraster obtusus ForBEs, Mem. Geol. Surv. Gt. Britain, vol. 2, pt. 2, 1848, p. 463; Mem. Geol. Surv. United Kingdom, dec. 1, 1849, p. 2, pl. 1, fig. 3.—Murcutr- son, Siluria, 1854, p. 182, fig. 17. Palzaster obtusus SattER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326.— Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 24.—Satrer, Mem. Geol. Surv. Gt. Britain, vol. 3, 1866, p. 289, pl. 23, fig. 1. Stenaster (?) obtusus Stiirtz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 153; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 41, 56. Stenaster obtusus SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pp. 22, 23, 31, text fig. 21, pl. 1, figs. 6, 7. The little that is known of this species appears to be in harmony with the characters of Stenaster as here defined. It occurs in the Caradoc beds (Ordovicic) at Drumcannon, Waterford, Ireland, and
in the Bala rocks west of Bala Lake (Moel-y-Garnedd), North Wales.
STENASTER (?) CORONELLA (Salter).
Palzaster coronella Sauter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326.— Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 25.
Stenaster (?) coronella Stiirtz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 153.
The description of this species is very short and almost nothing is known of its characters. It occurs in the May Hill sandstone (Siluric) at Gunwick Mill, Malvern, England.
STENASTER (?) CONFLUENS Trautschold.
Stenaster confluens TrautscHoitp, Nouv. Mém. Soc. Imp. Nat. Moscou, vol. 14, 1879, p.11, pl. 2, fig. 5—Scu6nvorr, Paleeontographica, vol. 56, 1909, p. 337.
Based on a fragment of the distal part of a ray. Appears to be a cryptozonian. Generic position unknown. From the Upper Car- boniferous (Moscovian) of Moscow, Russia.
Genus TETRASTER Nicholson and Etheridge (emend.). Plate 33, fig. 4.
Tetraster NICHOLSON and EruEertpGce, Mon. Silurian Foss. Girvan Dist., Ayrshire, fasc. 3, 1880, p. 324, pl. 21, figs. 3-8 (not figs. 1-2= Hudsonaster batheri, and 9-10= Urasterella girvanensis).
The name has reference to the four columns of actinal plates of the rays.
Remarks.—The authors of Tetraster distinguished their genus from Palzaster on the ground that it had on the actinal side but four columns of plates, while that genus as typified by P. matutinus, now Hudsonaster matutinus, has six. In this definition they are correct, but they complicated their good intentions not only by referring to
168 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Tetraster another Cryptozonia form (Urasterella girvanensis, new species), but also by confusing with their genotype specimens that certainly have the character of Palzaster so far as six columns of actinal ossicles are concerned. ‘This latter admixture the writer has taken out of the genotype and has described it in this work as Hudson- aster batheri. The adjusting of this matter has been made possible - through the kindness of Dr. Bather, who made for this work wax squeezes of the various specimens. After seeing these and the other material originally referred to Tetraster by Nicholson and Etheridge, their various drawings became clear. Their figures are fairly good, but in places do not bring out all the characters, but it was the mixture of three generic forms under Tetraster that made it for a time impossible to determine on what the genus should stand.
Emended description.—Small, five-rayed asterids, R = about 5 mm., r=about 2 mm. Abactinal side unknown. Actinally convex and in its general expression reminding much of living species with large marginals, but in Tetraster the comparatively massive margining . plates are adambulacralia.
Adambulacrals compose the entire outer actinal areas of Tetraster and margin the entire animal. Distally the pieces are small and the 12 ossicles of each column increase rapidly in size with the largest basal pieces of adjoining columns making the prominent interbrachial areas. Ambulacrally all are somewhat excavated, stand high above the furrow and each ossicle terminates in a ridge that joins those of the ambulacrals. All of these plates are abundantly granular.
Ambulacral furrows not wide but rapidly becoming very deep proximally, with excavated adambulacral sides. The columns meet in front of the two largest interbrachial adambulacrals. Podial openings are large and issue deeply from beneath the adambulacrals and between the lateral sutures of the ambulacralia. The pieces of the ambulacral columns are as many as there are adambulacrals and are placed directly opposite one another. Medially the ambulacralia are elevated, roof-like, and without a central gutter.
While the abactinal area is unknown, it appears that the adambu- lacrals also margin this side of the animal. The nature of the skele- ton inside of these columns may be of small pieces as in Urasterella, or, what seems more probable, consist of large radial and supramar- cinal ossicles, without accessory pieces.
Spines of any kind are unknown.
Genoholotype.— Tetraster wyville-thomsoni Nicholson and Etheridge ~ as above emended. T. (2) imbricatus (Salter) is also placed under this genus for the present.
Tetraster as now defined is so distinct in its great adambulacral development that it will not be confused with any other Paleozoic genus except Stenaster. Both genera, so far as the actinal area is
REVISION OF PALEOZOIC STELLEROIDEA. 169
concerned, are closely related. The differences, however, are worthy of generic rank. In Stenaster the rays are petaloid, with the adambu- lacrals largest at the mid-length of the rays, while in Tetraster the rays are triangular, with the greatest ossicles in the axis.
At first the genotype looks as if one had a direct representative of living Phancrozonia, but a little study quickly shows that the large actinal margining plates are not marginals or inframarginals, but adambulacrals, and therefore indicate a cryptozonian form. For a while it seemed that these large plates must be inframarginals, but then adambulacrals should be present, and they were looked for along the vertical ambulacral walls, but even here there are no diminutive pieces of these columns. Among Paleozoic asterids the writer has not seen aform without adambulacrals, and when there are but four actinal columns it is always the inframarginals that are diminutive or absent.
This species may be identical with 7. (?) wmbricatus (Salter), which see for further remarks.
Distribution.—Restricted to the Upper Ordovicic at Thraive, Gir- van, Scotland. The specimens occur as very sharp natural molds in a micaceous sandstone, from which good wax squeezes can be made, revealing all the skeletal characters. The originals are in the collec- tion of Mrs. Robert Gray, Edinburgh, Scotland.
TETRASTER (?) IMBRICATUS (Salter).
Palzaster imbricatus Satter, Mem. Geol. Surv. Gt. Britain, vol. 3, 1866, p. 289, pl. 23, fig. 8.
Original description —“‘P. rigidus, uncialis. Radii breves conici, nec ad basin valde expansi, subcarinati, tuberculis seu jugis obliquis remotiusculis asperl.
“Ray conical, its length about five lines, its breadth at base less than two lines. Only two rays are preserved; these are convex, slowly tapering, somewhat carinate above (we do not see the lower side), and ornamented by tubercles gathered into curved oblique rows, which run forward from the avenues toward the carina above, and are separated from each other by a space little more than their own breadth.
“Tocality: Caradoc rocks, Llanfyllin, Montgomeryshire [Wales]. The specimen is in the collection of Mr. Prosser.”’
Remarks.—As the writer has not seen the holotype, his conclusions are based on the lithographic figure, which adds but little knowledge to that in the description. As there are but two columns of dorsal ray plates, it hardly seems that the species is a phanerozonian. In general it looks most like Tetraster, but as the dorsal side of this form is unknown, no direct comparisons can be made between them. On the other hand, the imbrication of the plates, their large size,
170 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
and completely opposite arrangement suggest that 7. (?) umbricatus may be an auluroid. Until the original specimen is restudied no definite assignment can be given it.
MONASTERIDA, new family.
Progressive but primitive five-rayed Cryptozonia, with massive plates, especially the adambulacrals, which are conmon to the actinal and abactinal areas. Ambulacrals opposite. Interbrachial areas con- sist of a number of pairs of adambulacrals crowded orally Abacti- nally the radial and supramarginal columns consist of large, closely adjoining plates, and are similar to those of Hudsonaster.
Contains:
Monaster Etheridge.
Genus MONASTER Etheridge.
Palzaster (Monaster) EtHErince, jr. (part), Mem. Geol. Surv. New South Wales, Pal., No. 5, pt. 2, 1892, pp. 70, 71.
Etheridgaster GReGory, Geol. Mag., dec. 4, vol. 6, 1899, p. 353 (genoholotype, Palzxaster clarket).
Emended description.—Animal large, very stout, with five thick petaloid rays. Disk very large, with marked ray angles.
Abactinal area of rays with prominent radial, and supramarginal columns of large, contiguous, strongly convex, hexagonal plates, densely covered with small granules radially arranged. The ossicles of the radial columns alternate with those on each side and are largest in the mid-length of the rays, decreasing in size both distally and proximally, but most rapidly distally. This growth gives the ray columns a decided petaloid form. Outside of the supramarginals the animal is bounded by single columns of prominent, short, but very wide plates, which are the abactinal aspect of the actinal adam- bulacrals. These plates bear numerous spiniferous tubercles. The ossicles of the axillary disk region are not determinable. In the center of the disk there appear to be five distinct radials and a central disk plate, and around these probably were numerous small accessory pieces.
Madreporite abactinal, large, oval, radially striate, and situated near the axillary margin.
Actinally the rays consist almost entirely of the adambulacrals, which are numerous, abundantly tuberculate, short, and very wide. These columns increase rapidly in width, join and form angular axille, and leave between themselves deep petaloid ambulacral grooves. The interbrachial areas consist of the oral extensions of adjoining columns of adambulacrals, of which there are a great num- ber of pairs, terminating in the mouth in five small pairs, the oral armature.
REVISION OF PALEOZOIC STELLEROIDEA. Vil
Ambulacrals in two columns, opposite, short but wide, and about as numerous as the adambulacrals. Podial openings unknown.
Genoholotype.—Paleaster clarkei De Koninck. This is also the only species of Monaster and occurs in the ‘Upper and Lower Marine series’? of the ‘ Permo-Carboniferous”’ of New South Wales.
Remarks.—Mr. Etheridge proposed Monaster as a subgenus of Palzaster, from which it differs so radically as to give it easily the rank of a genus. He defines the group as follows: In Palzaster “the adambulacral plates, bordering the ambulacral avenues, are small and quadrangular, followed by large transverse marginal plates. In our Permo-Carboniferous species, on the contrary the adambulacral plates are transversely elongated, and occupy nearly the whole of the actinal surface on each side the avenues. The marginal plates [having reference to the plates along the margins which consist of adambulacrals, and also form part of the abactinal skeleton], in con- tradistinction to those of Hall’s Silurian species, are here smaller and subdorsal in position. The question now presents itself, of what value in a classificatory sense is this character? Hall lays particular stress on the position of these plates on the actinal side of Palzaster. He says it ‘has two ranges of plates on each side of the ambulacral groove; marginal {inframarginal] and adambulacral plates on the lower side, besides ambulacral or poral plates. The upper or dorsal side has three or more ranges of plates.’ In the case of our specimens, only one set of plates, excepting those of the ambulacral grooves, are, as before stated, absolutely actinal; the marginals [same usage as before] are strictly so, or, at the least sub-dorsal. Under these cir- cumstances, I purpose distinguishing our Australian species under the subgeneric name of Monaster (from the one or single row of adambulacral plates on each side of an ambulacral avenue).”
The original definition is here given at length to show that it can only apply to tho structure in Palzaster clarkei De Koninck, which is also the first species following the generic discussion. The author in the same work describes a new species which he also refers to Monaster, Palxaster ( Monaster) giganteus, but its structure is radi- cally different and does not conform with the subgeneric definition by Etheridge. Elsewhere in this work it is taken as the genotype of the new genus Australaster. Gregory in the serial above cited takes as the genotype of Monaster the last named species, the third of Etheridge, and transposes the former as the genotype to his new genus Htheridgaster. This the writer holds can not be done even though Etheridge selected no genotype for Monaster. That author’s genotype, as the name implies, refers to a species with but a single column of plates on each side of the ambulacrum. The species selected by a subsequent author should have the structure implied in the
Dg 4 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
original generic definition and when none actually applies, then the first species following the generic diagnosis. That Gregory fully appreciated the structural difference between Paleaster clarkei and P. (IM) giganteus is shown in his reference of the former to the order Phanerozonia and the latter to the Cryptozonia. Our disagreement is not as to structure but in the interpretation of the rules of nomen- clature. Under these circumstances P. clarkei is retained as the geno- type of Monaster, since it appears that P. giganteus has both infra- marginals and adambulacrals on tho actinal side, a structure quite different from that described for and present in Monaster Etheridge.
After the above was written in 1900, the writer explained by letter to Professor Etheridge what Gregory had done. Etheridge replied under date of June 6, 1900: ‘‘The laws of zoological nomenclature should have guided Doctor Gregory to have selected the first species described, as the subgeneric type, in the absence of any statement to the contrary on my part. As you say, Etheridgaster is certainly a synonym of Monaster.”’
Monaster is most like Hudsonaster. It retains the primitive pon- derous skeleton of the latter, but curiously has lost the inframarginal columns of ossicles, although the supramarginals are present.
MONASTER CLARKEI (De Koninck).
Palzaster clarkei Dz Konincx, Mém. Soc. roy. Sciences, Liége, ser. 2, vol. 2, 1877, p. 166, pl. 7, figs. 6, 6a; (David), Mem. Geol. Surv. New South Wales, Pal. No. 6, 1898, p. 127, pl. 7, figs. 6a, 6b.
Palxaster ( Monaster) clarkei ETHERIDGE, jr., Mem. Geol. Surv. New South Wales, Pal. No. 5, pt. 2, 1892, p. 71, pl. 14, figs. 1, 2; pl. 15, fig. 4.
Etheridgaster clarket GrEGorY, Geol. Mag., dec. 4, vol. 6, 1899, p. 353.
Of this species three natural molds have been found in the ‘‘ Upper Marine”? and ‘Lower Marine”’ series (Carboniferous) of Northum- berland County, New South Wales. The holotype in the Clarke collection was destroyed by fire.
The species attained a large size, the rays from the center of the disk to their extremities are not less than 5 cm., and in another specimen are 6.5 cm.
URASTERELLID, new family.
Teeniasteride Greaory (part), Geol. Mag., dec. 4, vol. 6, 1899, p. 351 (includes Texniaster, 2Stenaster, Urasterella, Protasteracanthion, Salteraster). Roemerasterine GREGORY, Treat. Zool., vol. 3, Echinoderma, 1900, p. 255. Specialized Cryptozonia, with alternate ambulacra, and with adam- bulacral type of oral armature. Rays five, rather flexible, long and gently tapering, proximally united without forming interbrachial areas. No inframarginals discernible as such at maturity, the actinal margin being occupied by well-developed-adambulacrals. Abactinal area, composed of numerous small plates arranged in columns and
REVISION OF PALEOZOIC STELLEROIDEA. 173
quincunx. The radial and supramarginal columns may be dis- cernible in somewhat larger plates. Adambulacrals many, like coins set on edge. Contains: Urasterella McCoy.
Genus URASTERELLA McCoy (emend.). Plates 27 to 30.
Urasterella McCoy, British Pal. Foss., 1851, p. 59 (not defined).— Hatz, Twentieth Rept. N. Y. State Cab. Nat. Hist., 1868, p. 289; rev. ed., 1868=1870, p. 332.— McCoy, Geol. Surv. Victoria, dec. 1, 1874, p. 42.—Zirre,, Handb. Pal., vol. 1, 1879, p. 453.—Strirtrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 152; Paleeontographica, vol. 36, 1890, p. 219.—Gregory, Geol. Mag., dec. 4, vol. 6, 1899, p. 352.
Stenaster Brines (part), Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 77.—Srirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 40, 56.
Roemeraster Sturtz, Paleeontographica, vol. 32, 1886, p. 85 (genoholotype, Asterias asperula Roemer); vol. 36, 1890, p. 220; Verh. naturh. Ver. preuss. Rhein1., etc., vol. 50, 1893, pp. 52, 73.
Protasteracanthion Stirrz, Paleeontographica, vol. 32, 1886, p. 90 (genoholotype, P. primus Stiirtz=Asterias asperula Roemer); Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 54, 75.
Palasteracanthion Stirrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 153 (genoholo- type, ‘‘A. primus’’= Asterias asperula Roemer).—Sttrrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 75.
Salteraster Stbrtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 43, 60 (genoholotype, Palxaster asperrima Salter).
?Eoactis SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, p. 30 (genoholotype, H. simplex Spencer=? Urasterella girvanensis).
Generic characters —Disk very small, without interbrachial ares. Rays five, very long and slender at maturity, but shorter and rapidly tapering when immature.
Abactinal side with very numerous small stellate plates, all of which, excepting one or three medial columns, are drawn out into more or less long, blunt, stout, erect, nonarticulating rods. The disk is occupied by a central plate and a first ring with five plates, which in some species are seen to be the basal radial plates, followed by a second ring with 15 plates. Five of the latter are the second proximal radial plates, and 10, basal plates of the supramarginal columns. Between the central plate and the first ring there may be inserted a few accessory, much smaller pieces. These disk ossicles may remain more prominent throughout life or may have the size of the other abactinal plates, in which case their arrangement is not plainly made out. In the center of the ray the adial column may be the more conspicuous throughout life or it may be more or less completely suppressed when the supramarginals adjoin and these may then
174 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
be the more prominent columns. Or the entire abactinal area of the rays may be composed of ossicles arranged in columns and in quincunx when the plates are of nearly equal size. The number of columns varies with age and in different species, the greatest number observed being 13 at the base of a ray.
Ambital plates often not readily distinguishable at maturity from the radial and supramarginal columns. The growing distal tips of the rays of Urasterella have no ambital plates, but shortly after their introduction they begin to develop the rodlike extension so charac- teristic of this genus. Of these columns there may be as many as four at the base of a ray on each side of the supramarginals.
Inframarginals, as such, usually not distinguishable at maturity from the ambital plates. Their position is rather abactinal than actinal. At the distal end of rays, however, these plates lose their ambital character, passing over somewhat to the actinal side, and closely adjoin the adambulacrals. In the young of U. ulrichi the inframarginals are well developed in the axillary regions and here there is also a single interbrachial marginal plate. More distally, however, the inframarginals have the character of the ambital plates. In none of the mature specimens have been seen well-developed or larger axillary inframarginals or interbrachial marginal plates. In U. asperula the axils have actinally single plates which may be remnant inframarginals.
Madreporite abactinal, of medium size, slightly convex, depressed and granulostriate.
Adambulacral plates very numerous, coin-shaped, and arranged on edge with the actinal surface pustulose. Each plate on its actinal surface bears two or three short, thick spines, and on its ambulacral side there is another similar spine. Along the outer edge of these plates toward the abactinal side there is another row of spines, in pairs, which are long and slender, flat, and longitudinally grooved on two sides. The adambulacral columns terminate in small tri- angular plates of the oral armature. In the young of U. ulricha five very stout, short, pointed spines (tori) are inserted inside of the plates of the oral armature.
Ambulacral columns with the.ossicles generally slightly alternating, but they may also be opposed, one plate to each adambulacral piece, more or less wedge- or club-shaped, and those of each column par- tially overlapping. Medially the columns loosely adjoin. Each plate is excavated laterally, along the proximal edge, leaving a more or less long, slender podial opening between adjoining plates.
Genoholotype.— Uraster ruthventi Forbes. The above diagnosis, however, is based on Stenaster grandis Meek, a form thought to be in generic harmony with the genotype.
REVISION OF PALEOZOIC STELLEROIDEA. 115
Distribution.—The species occur in North America and Europe and range from the Ordovicic to the Upper Carboniferous. The following are the known species:
U. pulchella (Billings). Trenton.
U. grandis (Meek). Richmond.
U. hualeyr (Billings). ?Chazy.
U. ulrichi, new species. Lowville.
U. girvanensis, new species. Upper Ordovicic of Scotland.
U. (?) asperrvma (Salter). Bala of Wales.
U. (?) constellata (Thorent). Siluric of France.
U. ruthvent (Forbes). Ludlow of England.
U. hirudo (Forbes). Ludlow of England.
U. selwynt McCoy. Siluric of Australia.
U. asperula (Roemer). Lower Devonic of Germany.
U., new species. Ithaca beds. Upper Devonic.
U. montana (Stschurowsky). Upper Carboniferous of Moscow, Russia.
Remarks.-—McCoy in suggesting the name Urasterella did it in the following words:
‘‘Before I was aware Prof. E. Forbes had described them it seemed to me that the U. [raster] Ruthveni and U. Hirudo, as well the similar American species, might be easily separated from the great star- fishes forming the recent genus Uraster, by their small size and much more simple skeletons, and I had named the genus Urasterella in my manuscript.”
This is all that McCoy did to establish the genus Urasterella, abandoning his manuscript definition on learning that Forbes had described the species as those of Uraster. Saltert in 1857 paid no attention to this name, although he was the first to recognize and define Palasterina, which McCoy proposed at the same time and in the same manner. It seems that Hall (1868, p. 332) was the first to revive the name Urasterella and regarded Billings’s Stenaster as a synonym by taking his second species, S. pulchella, as the genotype. Hall’s remarks are as follows: ‘‘Mr. Salter, apparently overlooking my description of Palzaster niagarensis, has placed both the above- cited European species [ Uraster ruthvent and U. hirudo] under Pale- aster, as defined by himself; but as it has been shown that this genus has two ranges of plates on each side of the ambulacral groove, these forms can not with propriety be arranged with typical Palasters.
“There was the same reason for adopting the generic term Uras- terella as for adopting Palasterina, both of which were proposed by McCoy at the same time, and the typical forms of each were specified. Mr. Salter has for some reason recognized the genus Palwaster pro-
1Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326, 50601°—Bull. 88—15. 12
176 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
posed by me a little earlier, but probably published after that of McCoy; and has given the two species of Urasterella to that genus. Now that there seems no reason for continuing them under that generic term, they should be restored to their proper position as indicated above. The two species of Forbes must either be placed under Urasterella as proposed by McCoy, or fall under the later genus Stenaster of Billings. Were the latter genus of my own proposing IT should nevertheless return to Urasterella, and I have no doubt that Mr. Billings will accord with this view.”
Paleaster pulchellus is a true Urasterella, but this does not make the genus Stenaster a synonym of Urasterella, smmce 8S. salteri Billings has quite another structure and is here accepted as the genotype of Stenaster.
Meek* also recognizes McCoy’s name, but because of certain pecul- larities in S. salterr, which he recognizes as the genotype, and also since he had not seen the dorsal side of McCoy’s S. grandis, he prefers to retain Stenaster for the latter.
McCoy returned to his genus in 1874, after going to Australia, and described a new form, U. selwyni. It is important to quote here his remarks:
‘“‘Genus Urasterella (McCoy) =Stenaster (Billings).
‘‘Gen. Char.: Small starfishes, with five moderate rays, narrowed at the base, and without disk. Ambulacral grooves narrow, bor- dered on the under side, with only one row of large (adambulacral) plates; no marginal plates. Upper surface with numerous rows of small tubercular plates. Confined to Silurian rocks.
‘“The late Mr. Salter and Mr. Billings refer the starfishes of this type to the subsequently published genus Paleaster of Hall; but, as Prof. Hall objects that his genus Palzxaster has ambulacral, adam- bulacral, and marginal plates, and the types of my genus U. ruthveni and U. hirudo of the English Ludlow rock, like our Australian species and the American Palzaster or Stenaster pulchella, have only one row of plates on each side of the ambulacral groove, I return to the use of my old generic name.” |
Zittel? says that Stenaster is a synonym for Urasterella and defines the latter genus.- Stiirtz? points out the errors in the diagnosis of Billmgs and that of Zittel, redefines the genus, and correctly states that Stenaster Billings contains species of two genera, that is, Sten- aster salteri, the genotype of Stenaster, and 8. pulchella, which he refers to Urasterella. In this way the genus Urasterella has come to be recognized.
The figure and description of Uraster ruthveni given by Forbes‘ appears to be of a species generically identical with the American
1 Pal. Ohio, vol. 1, 1873, p. 67. 3 Paleeontographica, vol. 36, 1890, p. 219. 2Handb. Pal., vol. 1, 1879, p. 453. 4 British Org. Rem., dec. 1, 1849, p. 1, pl. 1, fig. 1.
REVISION OF PALEOZOIC STELLEROIDEA. dee
Stenaster pulchellus Billings and this is the general consensus of opinion. The writer unfortunately had no material of the genotype of Uras- terella for study. However, since U. grandis is closely related to U. pulchella and shows so much more detail, it is here accepted as the genotype for the time being.
Professor Hall (1870) wrote: “‘In Stenaster= Urasterella, however, we have the absence of adambulacral plates.’”? This is nevertheless not the case, for the coi-shaped marginal series in 8. pulchellus are the ambulacral plates, since well-developed inframarginal plates, as in Paleaster, are absent in mature Urasterella. The inframarginals are, however, seen to be present in U. pulchella or in the distal ends of the rays in other species, though proximally they are so modified as not to be readily distinguishable from the ambital plates. In the axils of the young of U. ulricha the inframarginals are well developed, _ along with single interbrachial marginal plates, but in mature speci- mens of other species none have been seen.
Of Roemeraster the writer has seen three excetlent specimens skil- fully prepared by Stitirtz which clearly show that this genus has the generic structure of Urasterella. Stiirtz' describes this genus as having ‘‘strong marginal plates” inside of the ‘‘small, cornered adam- bulacrals.”” Our specimens do not show such plates, and if present they can not be adambulacrals. This fact can be demonstrated In a well-preserved distal end of a ray, where two columns are present on each side of the ambulacrals. The innermost column of closely adjoining plates increase in size, retain their position beside the ambu- lacrals, and become the most prominent of the entire animal, while the outermost column soon change in aspect, the plates become separated and assume the characters of the ambitat pieces. This is likewise true in the young of U. ulricht where the axillary areas also have distinct interbrachial marginal and two larger proximal inframarginal plates. Passing distally, the latter also soon change their form, are separated one from another and are not distinguish- able from the ambital plates. Stiirtz further describes and figures five interbrachial ossicles in mature Urasterella asperula which are also well developed in the young of U. ulrichi. Urasterella is an easily recognized genus and the triangular ambital plates drawn out into short blunt erect rods are peculiar to it, a character again re- peated in Roemeraster. Under these circumstances the latter appears to be indistinguishable from Urasterella. For other remarks see U. asperula. On the other hand, Gregory regards Roemeraster as a good genus and places it erroneously among the ophiuridlike asterids in the family Tzeniasteride.
' Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 52.
178 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
In regard to Protasteracanthion Stiirtz, see remarks under Uras- terella asperula, and for Salteraster Stiirtz see U. asperrima.
Urasterella differs from Stenaster as redefined in this work in having long, slender, flexible rays which are never short and petaloid as in the latter genus. Again, the adambulacral pieces of Urasterella are very numerous, thin, and coin-shaped, while in Stenaster they are few in number and comparatively thick; the ambulacral plates are wholly different.
The long, slender and flexible rays, the apparent absence of in- framarginal columns, and the absence of distinct interbrachial plates (these are not the same as the single axillary pieces seen in U. asperula) at maturity readily distinguish this genus from all other Paleozoic genera.
For the origin of Urasterella see U. ulrichi.
Eoactis —After this book was completed appeared the work of Spencer, with the new genus Hoactis. It is probable that the genus is good and can be distinguished from Urasterella, but the necessary comparisons can not now be made.
URASTERELLA PULCHELLA (Billings). Plate 28, figs. 3, 4; plate 30, fig. 5.
Palxaster pulchellus Brzines, Geol. Surv. Canada, Rep. Progress for 1853-1856, 1857, p. 292.
Stenaster pulchellus Bruines, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 79, pl. 10, fig. 2.—Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 28.
Urasterella (Stenaster) pulchellus Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 289; rev. ed., 1868=1870, p. 332.
The largest specimen from Middleville, New York (Hall collection), measures: R=52 mm., r=11 mm., R=4.8r. An individual of the usual size from Trenton Falls, New York (Mus. Comp. Zodl., No. 31), measures: R=30 mm., r=4 mm., R=7.2r. One from Ottawa (Geol. Surv. Canada collection) measures: R=25 mm., r=4 mm., R=6.1r. The smallest specimen seen (Mus. Comp. Zodl., No. 36) measures: R=7 mm., r=1.5 mm., R=4.7r. Width of rays at base in mature examples from 4.5 mm. to 7 mm.
Original description—‘‘ Diameter, 24 inches; rays subcylindrical, 24 lines in width at the base, with a length of 1 inch; disk 34 lines in diameter; grooves narrow, bordered throughout by narrow oblong plates, nine in the length of two lines; the length of these plates in a direction transverse to the rays is about 1 line; near the disk there appears to be but one row of marginal plates.”
Formation and locality—Restricted to the Trenton limestone. Most abundant at Trenton Falls, New York. From this locality
REVISION OF PALEOZOIC STELLEROIDEA. 179
there are two specimens in the New York State Museum and six in the Museum of Comparative Zodlogy, Harvard University, col- lected by Dr. C. D. Walcott (Nos. 31-36). The American Museum of Natural History has one specimen from Canajoharie, New York (No. 660); in the Hall collection, Albany, there is a specimen from Middleville, New York. At Hull, Canada, Mr. W. R. Billings col- lected two specimens; the type and another specimen were found by E. Billings at Ottawa, Canada; these are now in the Museum of the Geological Survey of Canada at Ottawa.
Remarks.—This graceful species has the essential structure of U. grandis and will therefore not require a detailed description. U. pulchella is from a lower geological horizon, is probably the an- eestor of U. grandis and has far less numerous abactinal plates, which on the disk reveal a primitive arrangement reminding one of Hudsonaster. In the center of the disk there is a single plate around which is a first ring of 5 basal radial plates followed by another with 15 plates. The plates of the second ring are a little more conspicu- ous than any other abactinal plates-and are disposed as follows: Five are radial in position and are the second basal plates of the 5 radial columns, while the other 10 are disposed interradially in pairs immediately on each side of the second basal radials. The plates interradial in position are the basals of the supramarginal columns. Between the central ossicle and first ring there appear to be a few small accessory plates.
The arrangement of the disk pieces above described is plainly preserved in a very young example (No. 36, Mus. Comp. Zodl.). The radial columns remain the most prominent while the supra- marginals a little distally from the base of the rays are not readily distinguishable from the other columns. Here and there an accessory piece may be inserted between the radials and supramarginals but the greater width of the rays is attained by increasing the size of these columns and by the introduction of ambital columns outside of the supramarginals. In a mature ray on each side of the radials proximally, there appear to be not more than four columns of plates but it is possible that a few pieces of a fifth column may be developed. The form and spinosity of the abactinal plates is as in U. grandis, except that the nonarticulating spines are less long in U. pulchella.
Inframarginal columns at first view do not appear to be present but a careful examination near the distal end of a ray reveals two columns of nearly equal-sized plates on each side of the ambulacral furrow. Here these plates closely adjoin, the adambulacrals are elongate subquadrangular and the inframarginals quadrangular in shape. Proceeding proximally the former become more prominent and wider but remain throughout closely adjoining. The inframar- ginals, however, gradually pass over to the abactinal side although
180 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
they remain beside the adambulacrals, become more and more spinose, longer than wide, and eventually stellate in form and then are inseparable from the abactinal plates. There are about 42 adam- bulacrals in each column.
U. pulchella is readily distinguished from U. ulrichi and U. grandis in being smaller, with more slender and graceful rays, and in its fewer columns of plates. From U. hualeyi it is distinguished by the less convex rays and the far smaller number of plates.
Cat. No. 60610, U.S.N.M.
URASTERELLA GRANDIS (Meek). Plate 27, figs. 6-8; plate 28, figs. 1, 2; plate 30, figs. 1-4.
Stenaster grandis Mrrx, Amer. Journ. Sci., ser. 3, vol. 3, 1872, p. 258; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 66, pl. 3 bis, figs. 7a-7¢c—Mmer, N. Amer. Geol. Pal., 1889, p. 283, fig. 432.
Urasterella grandis MrEx, Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 67.
Palzaster harrisi MxtER, Journ. Cincinnati Soc. Nat. Hist., vol. 2, 1879, p. 117, pl. 10, figs. 2, 2a.
Original description.‘ Attaining a very large size, with the body or disk comparatively small, or only of the breadth of the united inner ends of the five rays. Rays long, slender, gradually tapering, and very flexible, widest at their immediate connection with the body, where they seem to be more or less depressed, but becoming more nearly terete farther out. Dorsal side of body and arms com- posed of numerous subtrigonal pieces that rise into pointed tubercles, or sometimes assume almost the character of short spinules, and are arranged in quincunx, so as to form about eight rows near the middle of the rays; those of the outer two rows being a little larger than the others. Dorsal pores apparently. rather large, and passing through between the concave sides of contiguous pieces. Ventral side of body unknown. That of the rays composed of the usual single row of transverse adambulacral pieces on each side of the well defined, rather deep, and moderately wide ambulacral furrows. Adambulacral pieces rather more than twice as long as wide, with their longer diameters at right angles to the ambulacral furrows, and rounding over from end to end so as to be most prominent in the middle; while they do not connect with each other by flat sides, but have little projecting processes, and corresponding sinuses, apparently for the purpose of imparting greater flexibility to the rays.”
Emended description—The largest specimen being doubled over actinally does not permit of exact measurements, but it is, as near as can be determined, as follows: R=93 mm., r=9 mm., R=10.3r. Another specimen spread flatly measures: R=49 mm., r=6.5 mm., R=7.6r. The smallest specimen (holotype of Palzaster harrisi)
REVISION OF PALEOZOIC STELLEROIDEA. 181
measures: R=10 mm., r=2.5 mm., R=4r. Width of rays at base in mature examples from 7 mm. to 8.5 mm.
Rays at maturity very long, depressed subcylindrical in outline, slender and tapering slowly. Disk very small, formed by the united inner ends of the rays.
Abactinal area reticular, consisting of very numerous, highly conical, stellate plates, the radial columns and the plates of the disk most prominent, while the other ray plates (supramarginal and ambital) are smaller and irregularly triangular in form. AI! plates are more or less drawn out into stout, blunt, nonarticulating spines which are best preserved along the sides of the rays. On the disk the ossicles are arranged in a few concentric rows while on the rays they are in columns and in quincunx. Near the base of a ray in the largest specimen there are about 13 columns, diminishing to about 4 at the distal ends.
Madreporite of medium size, lobate, radially crenulostriate, situ- ated between two adjoming rays and about midway between the margin and center of disk.
Adambulacral plates slightly overlapping the ambulacral columns, diminishing in size distally, coin-shaped, arranged on edge, and vary- ing in different specimens from 60 to 110 in each range. In the youngest known example there are about 20 plates in a column. Each piece bears three or four short, finger-shaped, articulating spines, two or three outwardly disposed, and one placed near the inner base between adjoining plates. Along the outer margin of the adambulacral plates and abactinally to the thick finger-shaped spines there is a row of long, slender, flattened and longitudinally grooved spines, two to each ossicle. Orally the coin-shaped adam- bulacral plates are somewhat modified, stand less erect and ter minate in pairs of subquadrangular oral armature pieces.
Ambulacral grooves wide, shallow, and furrowed medially by a narrow angular gutter. Ambulacral plates of adjoining columns opposite or very slightly alternating, the pieces narrow, equaling in number the adambulacrals, slightly overlapping each other proximally and partially interlocking in the medial gutter. The ambulacral plates continue in undiminished size to the compara- tively small mouth, are highly convex and club-shaped, with the attenuated ends laterally disposed. The podial openings are between the attenuated ends of adjoining plates.
Locality and formation.—In the Richmond formation at Richmond, Indiana (type-locality), and in the vicinity of Waynesville, Ohio, where Mr. Harris secured six more or less mature and three young individuals, besides numerous fragments. A ray of this species was found by Mr. U. P. James near Dayton, Ohio. In the Gurley collection of the University of Chicago there is a young specimen (No. 10978) from near Ridgeville, Warren County, Ohio.
182 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Remarks.—The type-specimen of Palzaster harrisi Miller is undoubt- edly a Urasterella, and there are no characters other than size by which this individual can be separated from U. grandis. Of about the same age are three specimens in the Harris collection and another in the University of Chicago, and all were originally referred to P. harrist. One of these is nearly again as large as the type, is about one-half the size of U. grandis, and measures 49 mm. along the greater radius. The only marked difference between P. harrist and U. grandis is the smaller number of adambulacral plates in the former, a feature common to the young of many fossil starfishes when com- pared with the adults of the same species. In fact, the variation in the number of these plates in the two largest examples (64 and 110) is nearly as great as between the type of Palzaster harrist (22) and the smaller of the two largest specimens of U. grandis (64).
U. grandis is closely related to U. pulchella (Billings) of the Trenton limestone. These species are, however, easily distinguished, not only by the different geological occurrences, but in that U. grandis attains a much larger and more robust growth. The latter has also many more abactinal ossicles with longer nonarticulating spines, and the adambulacral columns have from 60 to 110 plates, instead of from 36 to 60 as in U. pulchella. U. grandis appears to be a direct descendant of the latter and has varied only in attaining a larger size and a greater number of plates.
U. grandis is also closely related to U. ulrichi, and both are nearly of one size. The latter, however, has the rays highly convex abac- tinally, the plates are smaller but as strongly spinose, and there are two columns of larger central plates, instead of one as in U. grandis. In the latter in the mid-length of the ray there are about 9 plates in a column in 10 mm., while in U. ulrichi there are from 11 to 12 in the same space.
Cat. Nos. 40885, 40887, U.S.N.M.
URASTERELLA HUXLEYI (Billings). Plate 29, fig. 2.
Stenaster huxleyi Buuines, Geol. Surv. Canada, Pal. Foss., vol. 1, 1865, p. 218, fig. 197.
R=58 mm., r=5.5 mm., R=10.5r.. Width of ray at base, 6 mm.
Original description.—“ Deeply stellate, 4 or 5 inches across; body small, less than half an inch in diameter; rays long; flexuous, sub- cylindrical, apparently angulated along the medium line on the upper side, uniformly tapering to an acute point. On the dorsal side the rays are covered by @ multitude of small subangular plates, each from one-fourth to one-third of a line wide. The central part of the body is not well preserved in the only specimen collected; but it is
REVISION OF PALEOZOIC STELLEROIDEA. 183
evident from a view of the plates which remain that they are here larger and more convex than those of the rays.
“Diameter of the body, five lines. Length of each ray, 12 inches. Width of the rays at their junction with the body, 3 lines. Depth of the rays from the dorsal to the ventral side of the body apparently somewhat less than the width. The total breadth of the specimen, if the rays were straightened out, would thus be about 4} inches.
“From the manner in which the rays are curved, it is evident that they possessed a considerable amount of flexibility. The specimen is somewhat distorted by pressure, but a small portion of one of the rays near the body seems to retain its natural shape, and it is here obtusely angulated along the median line. The transverse section of the ray should be, therefore, subpentagonal. There is still, how- ever, some doubt on this point. The under side is unknown.” In places where the specimen is broken the adambulacrals are seen to be as in other species of Urasterella; there appear to be about 60 or more of these plates in each column.
Locality and formation—tThe only specimen of this species was found by Mr. J. Richardson in strata of Chazy age (bed I of the Newfoundland section) at Point Rich, Newfoundland. The holotype (No. 554) is in the Museum of the Geological Survey of Canada, at Ottawa, which has furnished the photograph illustrating the specimen.
Remarks.—The holotype was seen at Ottawa and the original Ulustration found to be a fairly accurate reproduction of the charac- ters of the fossil. The abactinal side of the disk has a central disk plate that is large and tumid. Around it is a circle of six smaller, highly convex plates, and at the base of each ray medially there is another single large tumid plate, the basal radial. The abactinal side of the rays is highly convex and somewhat angulated medially. The ossicles are small and distinctly arranged in quincunx, of which there are about six plates in each diagonal row near the base of a ray. In other words, the abactinal characters of U. hualeyi are very much like those of U. ulrichi, with the differences that in the latter species the prominent disk plates are smaller and there are more columns of smaller ossicles on the stouter and longer rays. Further, in U. ulricht there are two columns of larger abactinal plates along the central area of the rays, while in U. huzleyi all the ray ossicles are of equal size.
U. pulchellus has less convex and more slender rays, and far fewer
abactinal plates. URASTERELLA ULRICHI, new species,
Plate 29, fig. 1; plate 30, figs. 6, 7.
The smallest specimen measures: R=14 mm., r=4 mm., R=3.5r. The best preserved specimen measures: R=45 mm., r=7.5 mm., R=6r. The largest specimen measures: R=78 mm., r=12 mm.,
184 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
R=6.5r. Width of ray at base in the different individuals 4, 7.5, and 9 mm., respectively.
Rays short and tapering rapidly when young but at maturity very long, highly convex abactinally, and tapering very slowly. Disk comparatively large in the young but small at maturity and formed by the united ends of rays.
Abactinal area of disk and rays composed of numerous small, tumid, or highly spinose plates which in the rays are arranged distinctly in columns and in quincunx. In the angles between all of the plates are left subcircular small openings. On the rays medially there are two columns of large convex plates, variously stellate and not produced into short, blunt rods. These are the supramarginals, and between them are a few widely separated plates of the radial columns. In the young the two proximal radial plates are sepa- rated from each other by from one to three supramarginals, while the third plate is separated from the second by three or four supra- marginals. In a mature specimen there appear to be about eight of these radial plates on each ray and distally they are separated from one another by five supramarginal ossicles. On each side of the supramarginal columns are from one (distally) to five (proximally) columns of smaller or accessory ambital plates. In a full-grown specimen there are 11 to 12 in 10 mm., triangular in outline, and drawn out into short, stout, blunt rods. In the center of the disk in the youngest specimen (probably also at maturity) there is a single large depressed plate around which is a first circle with 6 plates followed by a second having 16 pieces. Of the latter, 5 are basal radials, 10 basal supramarginals, and 1 the madreporite. All of. the disk plates are variously stellate, and are the largest plates of the abactinal area, the size gradually diminishing distally along the rays.
Madreporite concentrically striate, somewhat smaller than the basal supramarginals, between two of which it is placed.
Adambulacral plates seen only in the young specimen, very strong, carinated, subquadrate, wider than long, and about 19 or 20 in each column 10 mm. long, not counting the oral armature pieces, which are subtriangular in outline. Inside of each pair of oral armature plates is placed a very stout but short subcircular spine which has not been observed in other species. No other spines are preserved.
Ambulacral furrows very narrow and deep, concealing the ambu- lacral plates.
In the axils of the youngest specimen, outside of the adambulacrals, are situated three prominent plates, the proximal one being the smallest. On each side of these along the ray is a single column of plates which rapidly diminish in size and separate with increasing interspaces distally. Their number can not be made out, but they appear to continue to the tips of the rays, where plates occur that
REVISION OF PALEOZOIC STELLEROIDEA. 185
are not ambital. In the mid-length of the ray, however, these plates greatly resemble the ambitals. Judging from the manner in which they appear distally, their form and constant position beside and outside the adambulacrals leads to the conclusion that they are the inframarginals. Whether the inframarginals and interbrachial mar- ginals are present at maturity cannot be determined.
Formation and locality.—Three specimens from the top of the Black River limestone immediately beneath the Black River shale, or from the Vanuxemia bed of the Black River (Mohawkian) group at Minne- apolis, Minnesota. The specific name is after the distinguished paleontologist, Dr. E. O. Ulrich, who found all the specimens. They are in the United States National Museum.
Remarks.—This species is distinguished from other Ordovicic Urasterellas by the few and widely separated plates of the radial columns, and by the prominence of the supramarginal columns, which in the other species are not distinguishable from the ambitals. The convexity of the rays abactinally is also greater than in the other species excepting U. hualeyi, but that species is further dis- tinguished in that it has smaller plates, there being from 7 to 10 in 5 mm., while in U. ulricht there are only 5 to 6 in the same space.
U. ulricht and U. grandis attained a similar large size. The former, however, is from a much lower horizon, has very convex rays abac- tinally, two columns of larger central plates (supramarginals) instead of one (radial), and the plates are smaller and therefore more numerous.
The young of this species are very interesting in that they show distinctly the presence of large inframarginal and interbrachial marginal plates in the axils. In U. pulchella none of these plates have been seen in the axils, but the inframarginals are believed to be present in the very small plates which are indistinguishable from the ambital pieces situated along the greater length of the rays out- side of the adambulacrals. The same appears to be true for U. grandis. The young of U. ulrichi in its general structure reminds one much of Mesopalxaster shaffert, and it is probable that Mesopalxaster and Urasterella are derived from the same stock, which also gave rise to Hudsonaster. The latter retains throughout life the primitive plate structure, while Mesopalxaster, and particularly Urasterella, develop in various ways an abundance of accessory plates.
The best preserved specimen of U. ulrichi (pl. 29, fig. 1) has two nearly fully grownrays and three short stumps. Oneof these short rays is so well preserved as to indicate that this condition is not due to poor preservation, but is apparently a case of accidental loss of parts during life. The wound has been healed, but no regeneration of lost parts has taken place, as is so common in similar losses among the living starfishes.
Cat. No. 60612, U.S.N.M.
186 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. URASTERELLA GIRVANENSIS, new species.
Plate 28, fig. 5.
Tetraster, sp. ind., NicHotson and Erueripce, Mon. Silurian Foss. Girvan Dist., Ayrshire, fasc. 3, 1880, p. 325, pl. 21, figs. 9, 10.
? Eoactis simplex SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Palzeontogr. Soc. for 1913), February, 1914, p. 30, pl. 1, fig. 4.
Urasterella girvanensis ScuucHERT, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 44.
Description by N. and E.—‘Body stellate, with slowly tapering arms, which increase little in width throughout their whole length [the distal ends being unknown]; upper surface unknown, but the body was convex and probably granular. [The pieces of the disk are seen through the mouth and consist of many tiny plates arranged in more or less regular circles about the slightly larger central ossicle.] Ave- nues of the arms broad, and not bridged over by any of the plates [this is a slip of the pen, for the ridged ambulacralia lie horizontal and deep in the grooves and are directly opposite one another; the podial openings are fairly large and in the usual position laterally]; marginal ambulacral plates [=adambulacrals] moderately convex, trans- versely elongated, or oblong in form, and less in width than the ambulacral plates; those in the angles of the rays are the largest, and somewhat more elongated than the others; oral plates not visible.” The interbrachial areas are structurally very interesting because in each one there is a single narrow but long axillary interbrachial ossicle that distaily margins the axil, and in front of this is a minute pair of adambulacral oral armature pieces. On either side of the axillary interbrachial are the most prominent adambulacrals, about five in number, being larger than the other distal ones, which are considerably narrower and of fairly uniform size throughout the rays.
Formation and locality —A single specimen from the Upper Ordo- vicic at Thraive Glen, Girvan, Scotland. A good wax squeeze of the holotype was furnished by Doctor Bather. The original is in the col- lection of Mrs. Robert Gray, at Edinburgh, Scotland.
Remarks.—This species is clearly a Urasterella, a fact which was also noted by Nicholson and Etheridge, as they state: “In some of its characters it approaches very closely to 7. (?) asperrimus, Salter, sp.” In its interbrachial skeleton U. girvanensis retains youthful generic characters, seen in the well-developed interbrachial axillary ossicles. After the above was written appeared Spencer’s paper above cited. Before the writer was aware of this work he had pro- posed the name JU. girvanensis. If we are treating of the same species Spencer’s name takes precedence.
Cat. No. 60611, U.S.N.M.
REVISION OF PALEOZOIC STELLEROIDEA. 187 URASTERELLA (?) ASPERRIMA (Salter).
Palzxaster asperrima Sauter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 325, pl. 9, fig. 1—Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, p. 24, fig. 15 (1).
Palxaster asperrimus SAuTER, Mem. Geol. Surv. Gt. Britain, vol. 3, 1866, p. 289, pl. 23, fig. 2.
Palxaster (?) asperrimus StURtz, Paleontographica, vol. 32, 1886, p. 91.
?Tetraster asperrimus NicHoLson and EtTueripGe, Mon. Silurian Foss, Girvan Dist., Ayrshire, fasc. 3, 1880, pp. 320, 321, 324.
Salteraster asperrimus Sturtrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 43, 60.
Nicholson and Etheridge wrote of this species as follows: It “is an unsatisfactory species. The specimens in the Museum of Practical Geology have the large transverse ossicles very apparent; but as to whether there is a row inside or outside these, or both, we are by no means certain. It appears, however, to have possessed only four rows.’ Under Tetraster they compare this species with their “7. sp. ind.,’’ which is a true Urasterella (U. girvanensis).
It seems best under these circumstances to refer this species to Urasterella, it being apparently near U. grandis. It is found in the Caradoc or Bala sandstones (Ordovicic), near Welshpool, North Wales. Should it prove to be generically different from Urasterella, then the name Salteraster Stiirtz can be revived, as he names P. asper- rimus as the genoholotype.
URASTERELLA (?) CONSTELLATA (Thorent).
Asterias constellata TuorENT, Mém., Soc. géol. de France, vol. 3, 1838, p. 259, pl. 22, fig. 7.
The original figure of this species does not permit of determining its generic position. It is described as having but one range of plates on each side of the ambulacral grooves, and the figure seems to indicate the presence of a large disk with well-defined interbrachial arcs. It seems to have moro of the characters of Urasterella than of any other genus.
The specimen was found in the Siluric (? Lower) strata in northern France (Mondrepuis, L’ Aisne).
URASTERELLA RUTHVENI (Forbes).
Uraster ruthvent Forses, Mem. Geol. Surv. Gt. Britain, vol. 2, pt. 2, 1848, p. 436; Mem. Geol. Surv. United Kingdom, dec. 1, 1849, p. 1, pl. 1, fig. 1; in McCoy, British Pal. Foss., 1851, p. 59.—Murcutson, Siluria, 1854, fig. 39-3.
Palxaster ruthvent Satter, Ann, Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326.— Wrieut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 25.
Urasterella ruthveni Forses, in McCoy, British Pal. Foss., 1851, p. 59.
This, the genotype of Urasterella, is unfortunately not well known, but appears to be congeneric with U. grandis and U. pulchella. It occurs in the Upper Ludlow beds (Siluric), near Kendal, Westmore- land, England,
188 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
URASTERELLA HIRUDO (Forbes).
Uraster hirudo Forses, Mem. Geol. Surv. Gt. Britain, vol. 2, pt. 2, 1848, p. 464; Mem. Geol. Surv. United Kingdom, dec. 1, 1849, p. 3, pl. 1, fig. 4; in McCoy, British Pal. Foss., 1851, p. 59.—Murcuison, Siluria, 1854, p. 221, fig. 39-2. Palzaster hirudo Sauter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326.— Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 25.
Urasterella hirudo ForBes, in McCoy, British Pal. Foss., 1851, p. 59. This small species has much the appearance of being the young of U. ruthveni. The form is said to be gregarious and is associated
with that species. URASTERELLA SELWYNI McCoy.
Urasterella selwynt McCoy, Geol. Surv. Victoria, Prodr. Pal. Victoria, dec.1, 1874, p. 42, pl. 10, figs. 2, 2a, 3, 3a.
Original description. Rays five, elongate, gradually tapering from a little beyond the base, which is slightly contracted, angulated on the upper side by a prominent ridge along the middle of each ray, having a row of conical tubercular plates (about eight in two lines), each side sloping on the dorsal aspect from the middle with about three rows of conical tubercular plates rather smaller than the middle row. The five axil plates small, ovate, triangular, very tumid. Adambulacral plates large, extending to the tubercular margin, transversely oblong, about twice as wide as long (about nine in two lines). Ambulacral plates small, in a deep ambulacral groove. Length of ray from mouth to tip, six lines; greatest width near base, 14 lines. Surface of plates granular.
“This beautiful species is easily known by its strongly angulated rays on the dorsal side. The traces of oral plates are so very minute and indistinct that I can not give their character.
“This is the first fossil starfish seen in Australia, and I dedicated it to my old friend Mr. Selwyn, formerly Director of the Geological Survey of Victoria, and now Director of the Geological Survey of Canada, who collected it.
“This species is most nearly related to the Uraster ruthveni of Forbes from the Upper Silurian grits of Kendal in Westmoreland.
‘‘Common in the fine sandy Silurian beds of range on E. side of commonage reserve, Kilmore.”
Remarks.—This is clearly a species of Urasterella. Actinally it has in each axil one fairly large axillary interbrachial and in this recalls the same structure in U. girvanensis, new species.
URASTERELLA ASPERULA (Roemer). Asterias asperula RoEMER, Paleontographica, vol. 9, 1863, p. 146, pl. 24; pl. 26, fig. 6;\pl. 27: ee eee asperula StiRtz, Paleeontographica, vol. 32, 1886, p. 85, pl. 9, figs. 4, 5. Protasteracanthion primus Svirrz, Paleontographica, vol. 32, 1886, p. 90, pl. 11, figs. 3, 3a.
Remarks.—Of this species there are two specimens in the United
States National Museum purchased of Stiirtz, and two more are
REVISION OF PALEOZOIC STELLEROIDEA. 189
in the Yale Museum Collection. These show both sides of the species. U. asperula is said to be common in the roofing slate of the Lower Devonic at Bundenbach, Germany.
There can be no doubt that Asterias asperula Roemer is a true Urasterella. All the generic characters are shown, even the longi- tudinally grooved spines and the rodlike extensions of the ambital plates. For further remarks on this species see generic discussion.
The abactinal structure of Roemeraster asperulus reminds one much of Urasterella pulchella of the Trenton, which is the least specialized species of the genus. The single interbrachial plate retained to maturity reminds one of the young of U. ulricht. In this character . U. asperula appears to be primitive. In the proximal third of the rays in U. asperula the radial columns are the most marked and the plates continue to increase in size toward the disk. The supramar- ginals are also well developed proximally, but the two or three proximal plates are smaller and depressed, so that the ten basals along with the five radials do not make so prominent a ring of large ossicles as in U. pulchella or in the young of U. ulrichi. Distally the rays in U. asperula have the plates of nearly equal size, although the columnar and quincuncial arrangement is retained. The center of the disk is occupied by a prominent central disk-plate and the
first ring consists of five radial plates as in U. pulchella. Cat. No. 59382, U.S.N.M.
URASTERELLA, nev species.
In the paleontological museu.z of Cornell University there is a large slender-rayed specimen having the general form and structure of Urasterella. There is, however, so little of the actinal detail pre- served that nothing more can be done than to indicate the presence of this species.
The specimen was found by Mr. J. B. Woodworth at Brookton, near Ithaca, New York, in the Upper Devonice.
URASTERELLA MONTANA (Stschurowsky). Palzxaster montanus ScH6NvorrF, Paleeontographica, vol. 56, 1909, p. 324, pl. 23, fig. 1; pl. 24, figs. 20-22 (complete bibliography cited here).
In general this form recalls U. grandis but is somewhat smaller and stouter. The actinal side alone is known, showing a wide ambu- lacral furrow bordered by stout columns of narrow adambulacrals. All of the ossicles of the ambulacrals and adambulacrals are opposite one another. Oral armature decidedly adambulacral in composition. Interradial areas described as having ‘‘a few plates.” A section through a ray (Schéndorf’s fig. 22) shows that abactinally on each side of the radialia there are four columns of ossicles, or nine in all.
Dimensions, about: R = 35 mm., r = 6-7 mm., R = 6r. Width of ray at mid-length about 6 mm.
190 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Formation and locality.—The holotype is from the oldest Upper Carboniferous (Moscovian) of Mjatschkowa, near Moscow. The specimen is now in the Bergakademie at Berlin, Germany.
CALLIASTERELLID, new family.
Calliasteride ScubnvorF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 251.
Cryptozonia with ophiurid expression; a small disk with primitive plate arrangement and five long, very flexible rays, with radialia and supramarginalia. No interbrachial areas. Ambulacrals oppo- site.
Contains:
Calliasterella, new name.
Genus CALLIASTERELLA, new name. Plate 31, fig. 3, text fig. 11.
Calliaster mirus TRAuTSCHOLD (not Calliaster Gray 1840, Echinoderma), Nouv. Mém. Soc. imp. Nat. Moscou, vol. 14, 1879, p. 108, pl. 18, figs. 3a-3h, 4.— Scubnvorr, Palzeontographica, vol. 56, 1909, p. 327, pl. 23, figs. 2-5; pl. 24, figs. 1-18; text fig. on p. 328.
Calliasterella ScuucuERt, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 14.
A cryptozonian asterid with the general expression of the ophiurid Onychaster.
Description —Disk relatively small, primitive, with rather large, decidedly spiculate ossicles. Rays five, long and slender, round in section. R=about 120 mm., r=30 to 35 mm., R=4r. Width of ray at mid-length about 15 mm.
Abactinal disk plates in form and position as in figure 11. There is a small central five-rayed plate with the rays in the position of the five arms. Around the central plate is a first ring of five larger basal radial plates. Then comes a second ring of ten plates, five of which are the second basal radialia; the other five are interradial in posi- tion and give rise in the next ring to the ten basal inframarginal ossicles. The third ring has five radialia and ten basal inframargi- nals. All of the ossicles in the three rings are variously six-rayed, with large rounded openings between the adjoining spicular ends. Between each pair of basal inframarginals are inserted single elon- gate interradial disk plates.
Madreporite unknown.
The rays abactinally have a medial column of transverse radialia, and alternating with these on either side are columns of supra- marginals. These ossicles are of peculiar construction, enabling the rays to flex about as in Onychaster.
REVISION OF PALEOZOIC STELLEROIDEA. 191
Ambulacralia small, adambulacralia larger, both very numerous in each column and in their disposition opposite one another. There are no inframarginals.
Oral armature of Cryptozonia construction and very much as in living Asterias glacialis.
Ocular plates probably not present.
Genoholotype and only species—C. mirus (Trautschold) (cita- tions as above). The holotype and three other fragments are from
R
Fic. 11.—THE PLATES OF THE DISK OF CALLIASTERELLA MIRA. SCHEMATIC. AFTER SCHONDORE. 1, CEN- TRODORSAL; 2, BASAL RADIALIA; 3, SECOND RADIALIA; 4, THIRD RADIALIA; 5, BASAL INFRAMARGINALS; 6, PAIRED INFRAMARGINALS; @, POSSIBLE POSITION OF ANUS; mdp, PROBABLE POSITION OF MADREPORITE.
the Upper Carboniferous (Moscovian), at Mjatschkowa, near Moscow. The holotype is in the University of Petrograd.
Remarks.—There is no other Paleozoic asterid worked out in such detail as is Calliasterella. Not only is the gross skeleton known, but the detailed construction of all of the essential ossicles and spines as well. Quarto pages of text and two plates are devoted to the skeleton.
The dorsal skeleton retains primitive construction, and although the ossicles are much modified, their general orientation is that of the older Phanerozonia.
COMPSASTERID AZ, new family.
Specialized Cryptozonia with decidedly spicular abactinal skele- ton, recalling that of Asterias. Ambulacra opposite or slightly 50601°—Bull. 88—15——13
192 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
alternating. Rays five, long, thick, and rounded in section. Disk not large. This family contains: Jaekelaster Sturtz. Compsaster Worthen and Miller.
Genus JAEKELASTER Sturtz.
Jackelaster Stiintz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 235-236, pl. 4, figs. 13-16.
Generic characters —Rays five, thick and long, 55 mm. in length, 16 mm. in greatest breadth, rounded distally. Disk large. Both rays and disk devoid of marginal plates.
Abactinally without columns of plates, entire surface decidedly and abundantly covered with ‘‘paxille.’’ Madreporite small, subcentral, radiately striate.
Ambulacral furrows wide, widest at about mid-length and nar- rowing both distally and proximally. Two col mns of podial openings. Ambulacralia narrow, L-shaped, slightly overlapping and slightly alternating proximally. Adambulacrals small, di- rectly opposite the ambulacrals. Outside of the rays the integu- ment bears spines and ‘‘paxille”’ abundantly.
Genoholotype and only species —2J. petaliformis Stitrtz (citations as above). Lower Devonic of Bundenbach, Germany.
Remarks —This genus is most closely related to Compsaster, in fact the general appearance of the two is very much alike.
Genus COMPSASTER Worthen and Miller. Plate 31, figs. 1, 2. Compsaster WortTHEN and Mixtsr, Geol. Surv. Ilinois, vol. 7, 1883, p. 327.
Original description.—‘‘Body stellate; central area or disk com- paratively small; rays large, long, more or less fusiform; grooves deep and bordered by numerous thin, subcircular, adambulacral plates. The ventral side of the typical species shows about six rows of plates upon each side of the ambulacral furrows, which have a regular, transverse as well as longitudinal arrangement.
“This genus is distinguished from all others in the family [their Paleasteride] by the number and form of the adambulacral plates, by the great number of disk plates upon each side of the ambula- cral furrows, and by the general form of the body and rays.”
Genoholotype-—C. formosus Worthen and Miller. It is also the only named species of the genus.
The adambulacral plates in Compsaster appear to be much as in Urasterella and both genera agree in having no distinct inframar-
REVISION OF PALEOZOIC STELLEROIDEA. 193
ginal plates. The ambital plates are very numerous, showing a dis- tinct progression to far more numerous columns of plates than in Urasterella. They also appear like those in this genus. It is prob- able that the abactinal area when it is known will be seen to have spicular ossicles like those of the ambital areas. COMPSASTER FORMOSUS Worthen and Miller. Plate 31, figs. 1, 2.
Compsaster formosus WorRTHEN and MILtER, Geol. Surv. Ill., vol. 7, 1883, p. 327, pl. 31, figs. 2a, 2b.
Original description.—‘ Body deeply stellate; central disk com- paratively small; rays rigid, large, fusiform, more than twice as long as the diameter of the central disk, and terminating abruptly in an obtuse point. The typical specimen furnishes the following meas- urements: Diameter of the body, 0.72 inch; length of ray from cen- tral part of disk, 1.78 inches; diameter of the ray at its junction with the bedy, 0.41 inch.
‘“Ambulacral grooves deep; ossicles rather small; adambulacral plates very numerous, and consisting of series of thin plates upon each side of the ambulacral furrows, which are rounded upon the exterior, prolonged below, and each bear a short, sharp spine on the upper part of the inner side, directed toward the apex of the ray. There are about eighty adambulacrals upon each side of the furrows, and they diminish very slowly in size toward the apex, after passing the fusiform enlargement of the ray.
“The disk-plates abut upon the adambulacrals in a straight line; they are subquadrangular, or polygonal, and each bears a strong central spine. Six longitudinal rows appear on the ventral side on each side of the ambulacral furrows; they are somewhat uniform in size, arranged in transverse, as well as longitudinal order, and are about two-thirds as numerous in a longitudinal row as the plates in an ambulacral series.
“Oral plates, madreporiform tubercle, and dorsal side unknown, except so far as we may judge of the spinous character of the plates from those visible on the ventral side.
“This large and beautiful species is so distinct from any hitherto described that no comparison is necessary for the purpose of identifi- cation.
‘Position and locality.—Okaw bluffs, between Chester and Kaskas- kia, Randolph county, Illinois; from the second division of the Chester limestone.
‘‘TIlinois State collection of 1880, by A. H. Worthen, No. 2476.”
The writer has not been able to consult the type-specimen.
194 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. COMPSASTER, new species.
Professor Weller collected an excellent asterid at Fountain Creek, Waterloo, Illinois (No. 14395, University of Chicago collection), showing the entire actinal side of a form that is nearest to C. formosus. It is, however, a smaller and more slender species, but until the abactinal surfaces of both species are known, one can not say that they are certainly of the same genus.
Measurements: R=20.5 mm., r=4.5 mm.
SCHUCHERTIIDA, new family.
Specializing Cryptozonia with well-developed pentagonal inter- brachial ares. Inframarginals well developed in the proximal regions where they remain adjoining the adambulacrals. Interbrachial and abactinal areas composed of small, more or less closely adjoining plates without regular arrangement.
Madreporite unknown.
Contains: Schuchertia Gregory.
Remarks.—This family is the most ancient and primitive of all large-disked or pentagonal starfishes devoid of marginals. In Schuchertia the first appearing inframarginals are retained through- out life and remain adjoining the adambulacrals in the axillary regions. These columns distally become less distinct and in the outer third of the rays are not distinguishable as inframarginals from the other smaller ossicles of the interbrachial areas. This therefore indicates that during the growth of Schuchertia the infra- marginals are in the process of elimination and in later forms seem to be completely disguised or lost. Then the plates of the inter- brachial and abactinal areas, while small, are usually strong, rarely spicular or stellate but never decidedly so, while in later genera the ossicles either break up into smaller and smaller plates, even into granules, or are spicular or thorny pieces. Even the adambula- crals which are well developed in Schuchertia may become greatly modified and almost eliminated.
In seeking for an ancestor for this family, it is plain that it came from a stock like Hudsonaster. This genus actinally has columns of ambulacral, adambulacral, and inframarginal plates; abactinally, inframarginal, supramarginal, and radial columns of plates. In addition there are five axillary marginals, and on the disk a ring of five basal radial and five interradial plates giving rise to the radial and supramarginal columns. ‘The first step from Hudsonaster toward Schuchertia would be a form of the former genus introducing small ambital plates. This type is as yet unknown, but is suggested in Urasterella. The progressive introduction of ambital plates and no
REVISION OF PALEOZOIC STELLEROIDEA. 195
development of small interbrachial pieces will tend to keep the inframarginals beside the adambulacrals. This is the case in Schuch- ertia where the axillary marginals are also retained, but this genus has progressed considerably beyond this stage, since the inframar- ginals fail to develop in the later growth, while the supramarginals and radials, as columns, are no longer distinguishable as such in any part of the individuals. The tendency of departure from [Hudson- aster therefore seems to be toward the breaking up and elimination of its essential structure into a mass of variously arranged small pieces, except the ambulacrals, which remain as columns of stout plates. Genus SCHUCHERTIA Gregory. Plates 32 and 33.
Palasterina Brurnas (part, not McCoy or Salter), Geol. Surv. Canada, Can. Org, Rem., dec. 3, 1858, p. 76.
Schuchertia GreGorY, Geol. Mag., dec. 4, vol. 6, August, 1899, p. 351.
Trentonaster Sturtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 224, 225 (based on same genoholotype as Schuchertia).
Original description.— Paleasterinide with tessellate exoskeleton ; the rays are short and the general shape is pentagonal. R: ras 2:1, Interradial plates numerous, polygonal. Adambulacral plates large and hexagonal. Ambulacral furrow tapering uniformly toward the distal end.
‘“‘Alhed to Palzasterina by the general form of the body and the absence of the marginal plates.”
Emended description.—Rays five, short and slender. General form pentagonal. Disk large, with well-developed interbrachial ares.
Abactinal area composed of very numerous, small, tumid, non- stellate plates which are arranged in quincunx or columns. There are no radial, supramarginal, or ambital plates recognizable as such, nor is the margin bounded by columns of inframarginals.
Madreporite indistinguishable amongst the abactinal plates.
Actinally the ambulacral furrows are very narrow, bounded by columns of adambulacral plates. Adjoining these in the proximal regions are distinct “axillary marginals” and inframarginals, the latter distally becoming smaller, and these continue either closely adjoining or are separated from one another by increasing interspaces. In the latter case they are not readily distinguished from the inter- brachial accessory plates.
Interbrachial areas occupied by numerous small accessory plates and like those of the abactinal area with which they are continuous.
Ambulacral plates apparently slightly alternating.
Genoholotype (of both Schuchertia and Trentonaster).—Palasterina stellata Billings. The generic description is, however, largely based on S. laxata, new species. :
196 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Distribution.—Ordovicie and Siluric of North America. Con- tains the following species: S. stellata (Billings). Trenton, Ottawa, Canada. S. laxata, new species. Richmond of Ohio. S. ordinaria, new species. Basal Siluric. Girardeau lime- stone, Alexander County, Illinois.
Remarks.—Schuchertia need only be compared with Petraster and Palasterina. The former differs in that the incomplete columns of inframarginals adjoin the adambulacrals and are not separated from them by interbrachial accessory plates as in the other two genera. Petraster is readily distinguished by the prominent columns of infra- marginals bounding the entire animal and abactinally by the distinct columns of radial, supramarginal, and ambital plates. In Schuchertia the plates of the abactinal and interbrachial areas are alike and not distinguishable into the kinds of columns just mentioned for Petraster.
The fact that in Schuchertia the ‘axillary marginals” and infra- marginals remain beside the adambulacrals seems to indicate its origin in forms like Hudsonaster. The generic structure of the latter is retained in Schuchertia, to which is added along the margin (mainly axillary) a series of interbrachial accessory plates. The generic structure of Hudsonaster is also retained in Petraster, but here, unlike those in Schuchertia, the interbrachial accessory plates are developed between the inframarginals and adambulacrals, forcing these columns apart. The phylum starting in Schuchertia is not a prolific one, but the other, Palasterinide, whose inframarginals are true marginals, is not only more prolific in genera but also has a longer geological range. Beginning in Petraster of the Ordovicic, it is continued in the Siluric in Lindstrémaster and Palasterina.
SCHUCHERTIA STELLATA (Billings). Plate 32, fig. 2; plate 33, fig.1.
Palasterina stellata Bruurnes, Geol. Surv. Canada, Rep. Progress for 1853-1856, 1857, p. 290; Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 76, pl. 9, figs. la, 1b—Wrieut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1, (Palzontogr. Soc. for 1861), 1862, p. 27, fig. 16 on p. 26.—QueEnsrept, Petre- factenkunde Deutschlands, vol. 4, 1876, p. 74, pl. 92, fig. 34.
Trentonaster stellata Svitrtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 217, 224, 225.
Description of 1858.— Pentagonal; disk about one-half of the whole diameter; ambulacral grooves narrow and deep, bordered on each side by a row of small, nearly square adambulacral plates; a second row consisting of disk plates extends nearly to the end of each ray, the remainder of the disk covered with smaller plates. All of these plates are solid and closely fitted together; the disk plates in the
REVISION OF PALEOZOIC STELLEROIDEA. 197
angles in contact with the oral plates are much larger than any of the others.
“Tn the only specimen in the collection the length of the rays measured along the ambulacral grooves is three lines; number of adambulacral plates on each side of the grooves sixteen; the rays diminish somewhat rapidly in size, and terminate in a rounded point; diameter of the disk four lines. The plates are all a little worn, so that the character of their surfaces can not be observed; they were probably nearly smooth.”’
Emended description.—Measurement of the immature type-speci- men: R=6 mm.,r=3 mm. Larger specimen: R=9 mm., r=4 mm.
Abactinal area composed of a series of plates which are more or less closely adjoiming and on the rays are arranged in distinct but twisted columns. This twisting is due to the insertion of new columns of plates, always on the right side, crowding the older ones to the left. The plates on the rays are subquadrangular to elongate subquad- rangular, increasing in size proximally, and on the disk are largest and generally subcircular in outline, or faintly stellate. The plates appear to be smooth. At the apex of the ray are two somewhat larger plates followed by three columns and on each side of these there are two other columns of ossicles. Near the beginning of the interbrachial ares the rays have from seven to eight columns of plates.
Madreporite not distinguished among the abactinal plates.
Actinally the most conspicuous columns are the adambulacrals bounding the very narrow ambulacral grooves. These ossicles are subquadrangular in outline near the base of the column, but become wider than long distally; there are about 15 in a column, terminating proximally in two larger, prominent, wedge-shaped plates of the oral armature. Interradially upon each pair of oral pieces is placed a large, single, pentagonal plate (holds the position of axillary interbrachials), against which rest- two diverging inframarginal columns, each with 13 or 14 ossicles, and these columns continue adjoining the adambulacrals. Before attaining the distal ends of the rays they gradually become smaller and pass over to the abactinal side. Other actinal disk plates are also present, but apparently are arranged in quincunx, and are smooth like those of the abactinal side.
Ambulacrals unknown.
Formation and locality—Ordovyicic. The holotype (No. 1399, Geol. Surv. Canada collection) showing the actinal area was found by Mr. E. Billings, at Ottawa. Another specimen, also in the Museum of the Geological Survey of Canada, and showing the abactinal area, was found by Mr. J. S. Stewart on Governor General Bay, near New Edinburgh, Canada.
Remarks.—This little Ordovicie asterid is distinguishable from other species with large interbrachial arcs in that it is devoid of all marginal and radial columns of plates. From S. lazata it is differ-
198 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
entiated by its smaller size, less numerous plates, and by the rela- tively greater size of the disk ossicles.
SCHUCHERTIA LAXATA, new species.
Plate 32, fig. 3; plate 33, figs. 2, 3.
The best specimen measures: R= 18 mm., r=6 mm., R=3r. The University of Chicago individual: R= 23 mm., r=about 8 mm. R=2.8r. Other specimens indicate a growth twice as large as the former one.
Rays short and slender. Disk and interbrachial ares large but not nearly so large as in Petraster speciosus. Six specimens are known, four of which are poorly preserved and but a jumble of plates. The specific name is given to indicate the generally separated condition of the plates.
Abactinal areas of rays and disk composed of very numerous, small but irregularly sized, subquadrate or diamond-shaped, shghtly pustulose plates. The arrangement is mainly in quincunx but a columnar arrangement is also noticeable.
Madreporite not distinguishable amongst the abactinal plates.
Ambulacral furrows very narrow, hardly revealing the carinated ambulacral plates. The podial openings are between the plates along their lateral corners.
Adambulacral plates very convex, a little wider than long, with the inner edge more or less pointed, against which terminates the carina of the ambulacral pieces. There are about 15 of the former plates in 15 mm. along the base of the columns. Actinally the adam- bulacral columns are the most conspicuous, since the inframarginals beyond the mid-length of the former columns appear not to be separable from the adjoining interbrachial pieces. The inner side of the adambulacrals bears tufts of short blunt spines.
Inframarginals recognizable as such only within the axils where they adjoin the adambulacral columns. Just within each axil there is a large single plate (axillary marginal) against which rest the infra- marginal columns. These plates decrease rapidly in size distally and are soon separated from one another so that the tenth piece from the axil is indistinguishable in shape and size from the interbrachials.
Interbrachial accessory plates very numerous, smallest in the inner axillary areas and thence increasing rapidly to a size maintained throughout the interbrachial areas. In form they are either diamond- shaped or subquadrate, centrally tumid, and each plate seems to have borne one central and two or three lateral spines.
Formation and locality.—Five specimens are in the Harris collec- tion, all from the Richmond (Waynesville), in the vicinity of Waynes- ville, Ohio. A fine specimen showing the abactinal area (University of Chicago collection, No. 10982) was found 7 miles north of Hamilton,
+ REVISION OF PALEOZOIC STELLEROIDEA. 199
Ohio. Another fragment was found by Mr. E. H. Vaupel at Oxford in the same State.
Remarks.—The only Upper Ordovicie species with which Schu- chertia laxata can be confounded is Petraster speciosus. However, there is one fundamental difference between them, so that even fragments can be distinguished. In P. speciosus the inframarginals are very conspicuous and bound the outer margin of the entire animal, while in’ S. larata there are no columns of marginal plates, since the inframarginals closely adjoin the adambulacrals. In other words, in the former species the interbrachial accessory plates are between the adambulacrals and inframarginals, while in the latter form. these pieces, which are also far more numerous, are all outside of the inframarginals. The generally disjointed condition of the plates in S. lazata will probably always distinguish it from P. speciosus.
Cat. Nos. 60613, 60623, U.S.N.M.
SCHUCHERTIA ORDINARIA, new species.
A regular species of Schuchertia.
The holotype shows the abactinal side only. R=11mm., r=about 6.3 mm.
This species is most closely related to S. lazata, but is smaller and with a comparatively larger disk. Therefore the rays do not protrude beyond the disk so far as in the latter form. Abactinal skeleton con- sists of minute tumid ossicles that are more cut along their edges than in S. lazata, and therefore more spicular.
The specimen can not be freed of the adhering clay sufficiently to make an instructive photograph, and is therefore not illustrated.
Formation and locality —The holotype is from the basal Siluric Girardeau limestone, Alexander County, Illinois. It is in the Gurley collection of the University of Chicago (No. 10992).
Family PALASTERISCID/E Gregory.
Palxbrisingidx Stiirtz, Paleeontographica, vol. 36, 1890, p. 246. Palzchinasteride Sviirrz, Paleeontographica, vol. 36, 1890, p. 246, also p. 247. Palasteriscide Grecory, Treat. Zool., vol. 3, Echinoderma, 1900, p. 257.
Specialized Cryptozonia with very large interbrachial ares. Abacti- nal and interbrachial areas either with a smooth membrane or granu- lar and thorny. No radial or supramarginal columns of ossicles. Inframarginals not present in any position. Madreporite probably always actinal. Ambulacrals alternating or opposite; adambulacrals more or less modified, but remain adjoining the ambulacrals.
Contains:
Palasteriscus Stiirtz. Echinasterella Stiirtz. Loriolaster Stiirtz. Cheiropteraster Stiirtz. For remarks on the course of development, see Schuchertiide.
200 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genus PALASTERISCUS Stirtz.
Palasteriscus Sttrtz, Paleeontographica, vol. 32, 1886, p. 95, pl. 14, fig. 1; vol. 36, 1890, p. 223, pl. 28, figs. 23-236; pl. 29, fig. 24; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 44, 61.
This genus differs from Loriolaster in being more decidedly stellate, with longer and more slender rays and less extensive interbrachial arcs. The abactinal and interbrachial areas are made up of innumer- able, small, variously shaped, loosely interlocking, stellate plates. These areas in Loriolaster appear to be smooth.
Madreporite very large, actinal.
The genoholotype, P. devonicus (same citations as above), is the only species and is very rare in the Lower Devonic roofing slates of Bundenbach, Germany.
Cat. No. 59389, U.S.N.M.
Genus ECHINASTERELLA Sturtz.
Echinasterella Sviirtz, Paleeontographica, vol. 36, 1890, p. 225, pl. 28, figs. 26, 26a, 27; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 53, 73.
This form seems to be closely related to Palasteriscus, and without material for examination it is difficult to pomt out the differences supposed to be generic. Sttirtz describes the ambulacrals as oppo- site, but his figures 26 and 27 show that they are slightly alternating.
The genoholotype, of which three imperfect examples are known, is EF. sladeni (same citations as above). It is from the Lower Devonie of Bundenbach, Germany. Another form which probably belongs here is F. (2) darwini Clarke, from the Devonic of Brazil.
ECHINASTERELLA (?) DARWINI Clarke.
Echinasterella ? darwini CuarKe, Monog., I, Serv. Geol. Min. Brasil, 1913, p. 315, pl. 27, figs. 9-12; Bull. N. Y. State Mus., No. 164, pl. 34, figs. 1-3.
Original description. ‘Of this fine starfish the collections con- tain two specimens, one, that from which our illustrations are taken, a sharp cast of an oral surface with the arms extended, in a shale sufficiently compact to permit a squeeze to be made of the entire ex- posure. The other is a considerably distorted individual also chiefly with oral exposure. Ihave placed the species only provisionally with Stiirtz’s genus Echinasterella, which was described from the Bunden- bach slates, feeling that in all probability both this species and its associated Aspidosoma? pontis will be found on close analysis by expert students of the Asteroidea to pertain to other genera. The structural features presented by £.? darwini are as follows: The oral surfaces of the arms are very broad, the ambulacral grooves narrow, and the plates arranged opposite each other. The ambulacral plates are turned obliquely inward and are broadened at their inner ends. As preserved these show only their upper edges except where
REVISION OF PALEOZOIC STELLEROIDEA. 201
turned somewhat more obliquely along the food groove. At the edges of these very broad ambulacral areas the adambulacral plates project in a single row on each margin, as rounded nubs or thickened elongated ridges, from each of which project not less than two and probably three spines. Inno place is the aboral surface of the starfish presented, but the madrepore plate is distinctly shown in one of the axillae, indicating its ambulacral position. This plate is round, con- vex, obscurely radiopunctate, and somewhat ridged. The oral appara- tus is indicated by thickened plates at the axillae, but their structure in detail can not be made out. The exampleserving as the type of this species has a radial length from center of mouth to tip of longest arm of 54 mm.”
Formation and locality—From the Devonic of Ponta Grossa, Brazil.
Genus LORIOLASTER Sturtz.
Loriolaster Stisrtz, Paleontographica, vol. 32, 1886, p. 94, pl. 12, figs. 3, 3a, 4; pl. 18, figs. 1, la, 2, 2a; vol. 36, 1890, p. 208, pl. 26, figs. 3b, 4a; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 47, 63.
Generic description.—Animal large, five-rayed, widely pentagonal, with very large interbrachial arcs entirely inclosing the rays. No marginal plates and seemingly with a parchment-like integument on the abactinal side and in the large interbrachial areas. The plates seen on the abactinal side resemble the aspect of the actinal plates.
Madreporite unknown.
Ambulacral plates alternating, numerous, considerably wider than long, with the podial openings tadepee iene:
Adambulacrals about as numerous as the ambulacrals, siete: shaped, greatly elongated laterally and bearing club-shaped carine (the regular arrangement of the latter seems to preclude their being articulating spines) which have on their outer lateral ends needle-like spines.
Oral armature pieces large, described as ambulacral.
The only known species is L. mirabilis Stiirtz (same citations as above), from the Lower Devonic of Bundenbach, Germany. It is not a common species.
Cat. No. 59380, U.S.N.M.
Remarks.—All of the Bundenbach material has been subjected to great pressure so that nearly all of the finer details have been obliter- ated and obscured by the adhering slate. However, L. mirabilis can not be confounded with any of the associated species because of the constant absence of the marginal plates and the smooth abactinal and interbrachial membrane. The latter may have been made up of very small calcareous pieces now obliterated by the great pressure to which these fossils have been subjected. Also see Cheiropteraster.
202 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genus CHEIROPTERASTER Sturtz.
Cheiropteraster Stiirtz, Paleeontographica, vol. 36, 1890, p. 228, pl. 29, fig. 33; pl. 30, fig. 32; Verh. naturh. Ver. preuss. Rhein1., etc., vol. 50, 1893, pp. 49, 68.
This genus has its nearest relationship in Loriolaster, from which it differs in having a far larger oral opening and markedly different ambulacral columns. These are small plates, in shape like the vertebre in teleost fishes, which alternate in adjoining columns and do not closely adjoin medially. Podial openings unknown.
Madreporite small, actinally situated near the mouth.
Abactinal and interbrachial integument granular and thorny.
Oral armature pieces small, described as ambulacral.
Genoholotype and only species.—C. giganteus Stirtz (same citations as above). This large species is very rare in the Lower Devonic roofing slates of Bundenbach, Germany.
Cat. No. 59381, U.S.N.M.
SCHGNASTERIDE, new family.
Specialized Cryptozonia with well-developed interbrachial ares. Abactinal area reticular, composed of numerous small plates. Inter- brachial areas with distinctly imbricating plates. Oral armature adambulacral. Adambulacrals well developed in the form of a rope (hence the name, from schoinos, a rope). Ambulacral plates and madreporite unknown.
Contains:
Schanaster Meek and Worthen.
Genus SCHC:NASTER Meek and Worthen.
Plates 32, 33, 35.
Schenaster MpEK and WortHEN, Proc. Acad. Nat. Sci. Philadelphia, vol. 12, 1860, p. 449; Geol. Surv. Hlinois, vol. 2, 1866, p. 277.—Zrrren, Handb. Pal., vol. 1, 1879, p. 453.
Original description.—‘‘ Animal consisting of a flattened pentagonal disk, with the angles more or less produced in the form of rays or arms, and the margins between the rays concave in outline, and fringed with short, flattened, spine-like appendages, which are also continued part of the way out along the lateral margins of the rays. Upper side of rays composed of a number of alternating solid plates, with the dorsal pores passing between them, while the angles between the rays are filled with similar plates, forming the upper side of the disk. Under side of the disk composed of numerous small plates, very distinctly imbricating inward and laterally toward the ambu- lacra. Ambulacral furrows (in the typical species) wide, deep, with on each side a single row of comparatively stout, squarish, or oblong adambulacral pieces, having an obliquely outward, imbricating arrangement, so as to present somewhat the appearance of a twisted
REVISION OF PALEOZOIC STELLEROIDEA. 203
cord, as seen from below; farther out these become the marginal pieces of the free rays. There is, however, no regular row of marginal pieces to the disk between the rays. [In other words, there are no infra- or supramarginals.] Oral pieces ten, anchylosed (?) in pairs, so as to look like five pieces merely emarginate at the outer and inner ends. (Other characters unknown.)
‘Of course it is not possible to give a systematic diagnosis of a genus like this, of which only imperfect fossil species are known. All that can be done, in cases of this kind, is to give such of the more prominent characters as happen to be visible in the particular speci- mens accessible; while we can not always be sure, until better speci- mens are obtained, and other species known, whether some of the characters given may not be merely specific, or in other cases of more than generic importance. At the same time, we have to regret our inability to give any information in regard to some of the more delicate parts that would be the first to claim the attention of the zoologist in describing existing starfishes.
‘‘Tn first publishing a description of the beautiful species forming the type of this genus, we referred it provisionally to McCoy’s genus Palasterina, under the subgeneric name Schenaster. Later com- parisons, however, have satisfied us that it can not properly be retained in that genus; and as it seems to present equally important differ- ences from all the other established genera known to us, we now propose to separate it as a distinct genus, under the name Schaenaster. It is probably most nearly allied to the Silurian genus, Palasterina, but differs in the peculiar oblique, outward, imbricating character of its row of plates on each side of the ambulacral furrows, and the distinet inward imbricating character of the minute, scale-like plates covering the under side of the disk. There are likewise differences in the arrangements of the plates and pores of the dorsal side of the free arms, as seen in our figure 7), pl. 19.
‘ “As the disk is not seen in the specimen from which figure 7d, of the plate just alluded to, was drawn, it presents so different an
“ appearance from fig. 7a of the same plate, showing the upper side of the fossil, that, looking at these figures alone, doubts might arise whether or not they belong to the same type. An examination, however, of the upper side of the same specimen from which 7d was drawn, as well as of other fragments, shows them to be thesame. A fragment of the same specimen from which fig. 7d was drawn also shows portions of the under side of the disk.
‘‘Another species, apparently of this genus, from the Burlington limestone, with much narrower ambulacral furrows', shows numerous
1“We should explain here, that the ambulacral furrow of the enlarged ray, represented by fig. 7c of plate 19, is proportionally too broad, in consequence of the accidental flattening of the specimen, and in part to the adambulacral pieces being represented proportionally too small. These furrows are more
nearly natural in fig. 7d, but even in that specimen they are proportionally wider than in undistorted examples,”
204 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
little, short, flattened, spine-like appendages protruding from these furrows, with an outward imbricating arrangement or inclination towards the extremities of the rays. There may have been other little spies over the outer surface, in addition to those fringing the margins of the disk, though the specimens retain no traces of them.’
Genoholotype.—S. fimbriatus Meek and Worthen. Lower Carbonif- erous (St. Louis) of Illinois.
The other three species referred to Schenaster probably do not be- long in this genus. The specimens have not been studied.
SCHCENASTER FIMBRIATUS Meek and Worthen. Plate 35, figs. 1-4.
Palzasterina (Schenaster) fimbriata MEEK and WortTHEN, Proc. Acad. Nat. Sci., Philadelphia, vol. 12, 1860, p. 449.
Scheenaster fimbriatus MerK and WortHEN, Geol. Surv. Illinois, vol. 2, 1866, p. 278, pl. 19, figs. 7a—7d.
Original description.— ‘Body regularly pentagonal star-shaped, with the rays produced into rather acutely pointed arms, which are convex above, and about equal in length to the diameter of the disk. Plates of the upper side of the arms and disk, convex, or even tumid; near the disk those of the rays hexagonal, heptagonal, or irrecular in form, alternating, and consisting of about five or six longitudinal rows, with a few much smaller intermediate pieces. Farther out the rays, they gradually pass into two mesial ranges of oblong, alter- nating pieces, with their longer diameter parallel to that of the rays; while on each side of these, minute irregular pieces fill the space between them and the marginal pieces. Toward the extremities of the rays, these little intermediate pieces diminish im size and at last become obsolete, leaving only the two middle and outer, or adam- bulacral rows. Ambulacral furrows, in apparently undistorted specimens, deep and nearly or quite twice as wide as the row of pieces on either side; adambulacral pieces rather thick and strong, and liable to present considerable differences in their obliquity and breadth of surface exposed, in consequence of the compression or distortion of the specimen. Plates of the under side of the disk, very much smaller than the adambulacral, closely crowded together, and owing to their imbricating arrangement, presenting much the appearance of the scales of a fish; immediately on each side of the rays, they imbricate toward the latter, but near the middle of the space between any two ambulacra, the imbrication is inward toward the mouth, so that in tracing the rows parallel to their longer diam- eter, across between the rays, they are found to describe a nearly semicircular curve, with a slight angularity near the middle.
“Near the extremities of the rays, the dorsal pores are seen to pass between the ends of the two mesial ranges of oblong pieces,
REVISION OF PALEOZOIC STELLEROIDEFA. 205
but farther in toward the disk they are more irregularly dis- tributed. Our enlarged figure 7b, pl. 19, represents these pores and the dorsal plates, as seen in one of the rays, with the convex outer portion of the plates ground away, in which condition the pores probably appear larger than natural. In specimens with the tumid portion of these plates unremoved, the pores are not readily seen, and the whole dorsal side then seems to be made up of solid, close- fitting pieces. Greatest diameter across between the extremities of the opposite rays, about 2.37 inches; diameter of disk, 1 inch; breadth of ambulacral furrows, about 0.10 inch; length of little flattened marginal spines, near 0.08 inch.
“ Locality and position.—St. Clair County, Illinois; in the St. Louis division of the Subearboniferous series.”
The specimen has not been studied.
SCHGENASTER (?) WACHSMUTHI Meek and Worthen. Plate 33, fig. 6.
Schenaster wachsmuthi Merk and WortTHEN, Proc. Acad. Nat. Sci., Philadelphia, vol. 18, 1866, p. 259; Geol. Surv. Illinois, vol. 3, 1868, p. 499, pl. 17, fig. 4.
Original description.—“ Body flattened or much depressed, with a regular, distinctly pentagonal outline, the angles being produced into five rather attenuated rays, which are a little convex above, and apparently as much as two-thirds as long as the diameter of the disk, if not more. Disk coneave in outline on the margin be- tween the rays, and imparting a slightly alate character to the latter by extending a little along their margins; like the dorsal side of the rays, composed above of numerous small, slightly convex plates. Dorsal pores moderately distinct between the plates. Plates of the under side of the disk about as large as those of the dorsal side, but flattened, scalelike, crowded, and having the inward imbricating character of the genus strongly marked. Ambulacra (as seen in a compressed specimen) very narrow, their marginal plates moderately large, oval-oblong, comparatively thin, and very strongly imbricating outward. Between these, two rows of short, flattened, spinelike scales are seen arising from the ambulacral furrow, and all inclinmg outward or toward the extremities of the rays. (Other characters unknown.)
“Diameter of disk, 1.32 inches; rays apparently extending as much as 0.90 inch or more beyond the margins of the disk.
“This species will be readily distinguished from our S. fimbriatus, of the St. Louis limestone, the only other species of the genus known to us, by its smaller and less convex plates on the dorsal side, as well as by its much thinner, less oblique, and more strongly imbricating row of plates along each side of the ambulacra, and particularly by its much narrower ambulacral furrows. We have not seen any
206 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
traces of the row of short, flattened, marginal spines seen around the disk of S. fimbriatus, in the form under consideration; nor have the similar little appendages arising in a double row from the am- bulacra of the latter been seen in S. fimbriatus. These, however, may be rather generic than specific characters, and consequently be found common to both species.
“The specific name is given in honor of Mr. Charles Wachsmuth, of Burlington, Iowa, the discoverer of the only specimen we have seen.”’
Formation and locality —Burlington limestone, Burlington, Iowa. The specimen has not been seen; it is in the Museum of Compara- tive Zoélogy, Harvard University (No. 7).
SCHCNASTER (?), new species.
In the Gurley collection of the University of Chicago there is a small specimen (No. 10993) from the Chester formation of Pope County, Illinois. According to the older classification it would be referred to Schenaster, but until this genus is thoroughly revised nothing of generic value can be done with these Carboniferous asterids. The specimen under discussion seems to be most closely related to S. (?) wachsmuthi.
Measurements: R=about 10 mm., r=about 3.5 mm.
SCHENASTER (?) LEGRANDENSIS Miller and Gurley. Plate 32, figs. 4-6. Schanaster legrandensis MiLLER and GuRLEY, Descr. new gen. and sp. Echinod., 1890, p. 56, pl. 9, figs. 7-9.—MitER, Sixteenth Rep. Geol. Surv. Indiana, 1891, p. 371, pl. 9, figs. 7-9; N. Amer. Geol. Pal., App. 1, 1892, p. 682, fig. 1246.
Original description— ‘Body thin, regularly pentagonal, sides concave, with long, nar.ow, gradually tapermg convex arms. Plates on the dorsal side of the disk in our specimen apparently anchylosed, and spines, if any belonged to the margin, broken away. Ventral side depressed and flat between the arm furrows, where it consists of very small plates, and if they imbricate inward the overlap must be very slight. Ambulacral furrows wide, deep; two rows of sub- quadrangular, ambulacral plates form the bottom of each furrow, on each side of which there is a row of oblong adambulacral plates, having an obliquely inward imbricating arrangement, presenting somewhat the appearance of a twisted cord; these are continued to the ends of the arms with the same obliquely inward imbricating arrangement. Five pairs of oral plates.
‘‘This species is small in comparison with the two heretofore described, has sides less convex, and narrower arms.”
Formation and loeality—IKinderhook limestone at Le Grand, Iowa. The specimen has not been seen; it may be in the Gurley collection of the University of Chicago. It is certainly not a form of Schenaster.
REVISION OF PALEOZOIC STELLEROIDEA. 207
SCHGNASTER (?) MONTANUS Raymond. Plate 33, fig. 5. Schenaster ? montanus RAYMOND, Ottawa Naturalist, vol. 26, 1912, p. 80, fig. 3 on p. 81.
Original description —‘‘ Animal small, about an inch in diameter. Rays short, slender, extending about one-half their length beyond the disk. Disk large, pentagonal, the margin slightly concave between the rays. The five proximal plates of the adambulacral series function as orals, while on the arms beyond the disk the adam- bulacrals become marginals. The adambulacral plates are rather small, oval, placed with the long axis diagonal to the axis of the arm. On the most perfect arm there are 16 of these plates on each side of the groove, not counting the proximal and distal plates.
‘“The ambulacral ossicles are small, arranged alternately. On this specimen they are mostly displaced. The plates on the disk between the rays are few and small. The marginals are small, rounded, and do not appear to bear spines, but this appearance may be due to poor preservation.
‘Locality —This species is described from a single specimen col- lected by the writer in the Madison limestone at Spring Canyon in the Ruby Mountains, near Alder, Montana. The type is in the Carnegie Museum, Pittsburgh, Pennsylvania.”’
PALAZOSOLASTERID A, new family.
Specialized multiradiate Cryptozonia with as many as 29 rays, large disk, and actinal madreporite. Ambulacralia opposite or slightly alternating.
Contains:
Palzxosolaster Stiirtz.
Echinasterias Stirtz.
Echinodiscaster Delage and Hérouard. Echinostella Stiirtz.
Medusaster Stirtz.
How rays are introduced in multi-rayed asterids—For paleontologic purposes it is not necessary to go deeply into this matter, but it is desirable to know when, where, and how the supernumerary rays are introduced in living forms so that we may be guided in our generic studies.
Ritter and Crocker’ have recently summed up what is known on this subject, and to their paper the reader is referred for further study.
In nearly all cases the multi-rayed forms have the rays of equal development, and for this reason it is the general belief that
1 Ritter and Crocker, Multiplication of rays and bilateral symmetry in the 20-rayed starfish, Pycnopodia helianthoides (Stimpson), Proc. Washington Acad. Sci., vo . 2, 1900, pp. 247-274.
50601°—Bull. 88S—15, 14
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adults have the full complement of rays characteristic of a species. In some forms there are individuals with smaller immature arms, but it is not certaim that these are newly introduced rays, or that ‘‘this disparity in size is due to the regeneration of the halves of automatically bisected animals” (p. 248). It is true that certain species start with the full complement of rays and introduce none in later growth. Others certainly deviate from this rule, and a species with as many as 37 rays has one small specimen with only 24 plus 2 young sprouting rays. It is therefore plain that ‘‘in Heliaster rays are added until far in adult life,” and it is also probable that ‘‘they are added in pairs” (p. 249). In Labidiaster as many as six new rays may bud simultaneously at intervals around the entire circumference of the disk.
An adult Pycnopodia has from 20 to 24 rays, and ‘‘this variation does not depend upon the size of the specimen. * * * The number is generally even, * * * but a few specimens with 21 have been found” (p. 250). The smallest specimen had six equal arms and two much smaller budding rays, one larger than the other. Between these two extremes all intervening stages occur. At least the original five and probably six rays are of larval origin, all the others being postlarval. When the sixth ray is introduced is un- known; the rest as a rule appear in bilateral order—that is, in pairs. They are all developed ‘‘in a budding area adjacent to I and II” on the side toward the sixth ray until late in adult life. When the arms are of unequal number it is due to the suppression of a ray. In Pycnopodia, therefore, ray multiplication goes on through a con- siderable part of adult life, but not the whole of it, and is variable with the individuals. All of the rays, whether of larval or post- larval origin, have the same structural characters.
Finally, it seems that the sixth ray in Pycnopodia has its origin in, or at least ‘‘is in some intimate way related with the larval organ of the embryo” (p. 268). Therefore multiradiation among asterids has its origin in late larval life.
In Heliaster, Clarke states,! “‘the formation of new rays is funda- mentally different from that in Pycnopodia.’”’ They do not develop in distinct generations, but appear entirely independently of each other. “A considerable number may develop at approximately the same time, often as many as six or seven and sometimes eight or nine in H. polybrachius, but they show no definite relation to each other.”’
The evidence seems “to show that they tend to arise in all four quadrants of the circumference of the starfish about equally, but successively rather than simultaneously.”’
1H. L. Clarke, Bull. Mus. Comp. Zodl., vol. 51, 1907, pp. 25-76.
REVISION OF PALEOZOIC STELLEROIDEA. 209
In Heliaster the original number is five, and the new rays are not as a rule disposed bilaterally (pp. 63-66).
Verrill (1914) states that Heliaster and allied living forms strikingly resemble Helianthaster of the Devonic, ‘and may indicate a con- tinuous descent from these ancient forms” (p.13). He also says, “I am inclined to believe that the increase in number of rays has been due more to the advantage gained in holding their food securely, and in opening bivalves, than for holding to the rocks, though both go together” (p. 16).
Genus PALZOSOLASTER Stitrtz. Plate 34. Palzosolaster Sturtz, Verh. nat. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 226-229, pl. 2, figs. 1-3. Helianthaster CLARKE (part), Bull. N.Y. State Mus., No. 121, 1908, p. 64, pl. 11.
Generic characters.—Disk very large, with 27 to 29 rays in the genotype, which project one-third their length beyond the disk. Animal large, up to 190 mm. in greatest diameter. Disk and rays without marginalia. Length of rays 95 mm., width of rays 7 mm.
Abactinal area decidedly and abundantly spinous and devoid of all columns of plates.
Actinally the great disk is also decidedly spinous. Rays slender, with wide ambulacra; ambulacral plates very narrow, seemingly alternating, but more probably opposite, F -shaped, with large podial Openings in two rows in each ambulacrum. The rays are bounded by narrow columns of small adambulacral ossicles that bear spines on their outer sides. Mouth circular and very large. The nature of the stout oral armature can not be made out.
Madreporite actinal, placed near the mouth, interbrachial, very large, striate, more or less oval, about 34 mm. in greatest width.
The general aspect is said to be much like the living Solaster affinis Brandt.
Genoholotype.—P. gregoryi Stiirtz (citations as above). Lower Devonic of Bundenbach, Germany. Another species occurs at this locality and a third is found in the Upper Devonic of New York.
Remarks.—For present purposes we may state that Palzxosolaster has from 25 to 29 rays and that the ambulacralia are arranged opposite one another; the other Stiirtz genera, Echinasterias, Echinodiscaster, and Echinostella, are so much like Palzosolaster that they may be disregarded.
Clarke recently erroneously referred another very well preserved species of this genus to Helianthaster (H. roemeri Clarke), but it plainly has no direct relationship with H. rhenanus. This is seen in the greater disk, larger number of rays, decidedly actinal position
210 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
of the madreporite and the absence of interbrachial inframarginals. It is clearly a Palzosolaster.
PALZZOSOLASTER (?) GYALUM (Clarke). Plate 34, fig. 1.
Helianthaster gyalum CiarKe, Bull. N. Y. State Mus., No. 121, 1908, p. 63, pls. oe Jae
Original description.—The New York specimens, ‘‘Helianthaster gyalum nov. are smaller than H. rhenanus. The arms are more numerous and appear to be quite uniformly 24-25. Compared to H. rhenanus they are relatively short, but very long compared with the size of the disk, which is much suppressed, and on none of the specimens, all showing the oral surface, is any distinct evidence of it visible, so deeply do the arms cut into it and so closely do they lie together. Notwithstanding this apparent retreat of the disk the madreporiform plate is very large. ‘This organ is preserved in but one example, but here it overlaps two adjoining interbrachial angles and the mouth parts pertaining thereto. Instead of being a flat or concave elongate plate, as in H. rhenanus, it is highly convex and circular; its surface markings less distinct and coarse in that species.
“The great oral aperture is margined by a series of pronounced ‘jaws’ or sharp projecting elevated angles the sides of which take origin from the margins of adjoining arms. These oral projections are slightly expanded at their tips into blunt points comparable to but smaller than the ‘Hocker’ of H. rhenanus, but like them carry small spines projecting inward. The solidity and strength of these mouth parts is indicated by their prominence and elevation as shown in figure. * * * The reentrant angle at the base of each arm is narrow, long, and acute, much more extreme in these respects than in H. rhenanus and very much‘more elevated.”
Actinally the rays have two columns of plates of which the ambu- lacrals are by far the most prominent, are opposite one another or slightly alternate, and occupy the comparatively wide ambulacral furrows. The adambulacrals are narrow columns and apparently as many in number as the ambulacrals. Laterally each adambu- lacral bears several spines.
Locality and formation.—A slab with three individuals from the Portage (Upper Devonic) at Earl’s quarry, Ithaca, New York, is now in Cornell University.
Remarks.—The writer has not seen these specimens, but the illus- trations seem to indicate that the ‘‘pronounced jaws” are made up of small ossicles of which there are at least five in each column. Further, that these ossicles are more probably the continuation of the narrow adambulacrals than of the ambulacral columns into the great oral area, and that proximally to these lie the minute pairs of oral armature pieces.
REVISION OF PALEOZOIC STELLEROIDEA. OT:
The madreporite in P. (?) gyalum, as in the forms of Palxosolaster, is very large, actinal in position, and placed even closer to the mouth than in any other species. Not only this, but it hes completely cov- ering one proximal ambulacral furrow and across parts of two adja- cent rays. Its general position and size are in harmony with Palzo- solaster and not at all with Helianthaster.
That P. (2) gyalum can not be referred to Helianthaster is therefore seen in the different position of the madreporite, the greater number of rays, the wider ambulacral furrow, and the improbability of its having three columns of abactinal ray plates in place of an integument bristling with spines. All of these differences are in harmony with Palxosolaster. Further, if P. (?) gyalum had interbrachial inframar- ginals as does Helianthaster, they should show somewhere on these five specimens, all of which preserve the actinal side. While these differences may not appear to be great, they make of Heléanthaster a phanerozonian and of Palzosolaster a cryptozonian.
PALZOSOLASTER ROEMERI (Clarke). Heliarthaster roemeri CLARKE, Bull. N. Y. State Mus., No. 121, 1908, p. 64, pl. 11.
From the Lower Devonic of Bundenbach, Germany. The holo- type is in the New York State Museum.
Genus ECHINASTERIAS Stirtz.
Echinasterias Sttrrz, Verh. nat. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 230, pl. 2, fig. 4; pl. 3, fig..5. The genotype has 25 rays, but otherwise appears to have all the generic characters of Palxosolaster. Genoholotype and only species—FE. spinosus Stiirtz (citations as = ay above). Lower Devonic of Bundenbach, Germany.
Genus ECHINODISCASTER Delage and Hérouard. Echinodiscus Stirtz (not Echinodiscus Worthen and Miller 1883, Echinoidea), Verh. nat. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 231-233, pl. 3, figs. 6-10. Echinodiscaster DeELAGE and Hfrovanrp, Traité de Zoologie Concrete, 1904. Echinodiscites ScuucHeRt, Fossilium Catalogus, Animalia, pt. 3, 1914, p. 15. One of the specimens has 29 rays and a greatest diameter of 160 mm. The writer fails to see how this genus is to be distinguished from Palzosolaster. It may be more abundantly spinose, and the madreporite is somewhat smaller and more coarsely striate, but these characters can hardly be of generic value. Genoholotype and only species.—Echinodiscus multidactylus Stiirtz (citations as above). Lower Devonic of Bundenbach, Germany. Cat. No. 59386, U.S.N.M.
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Genus ECHINOSTELLA Stiirtz.
Echinostella Stirtz, Verh. nat. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 233-235, pl. 3, fig. 11; pl. 4, fig. 12.
The only specimen has 28 or 29 rays and a greatest diameter of 150 mm. Abactinally the rays and the central area of the disk stand out rounded above the remainder of this side of the animal, which is not the case in Palzosolaster; otherwise the two genera are very much alike.
Genoholotype and only species.—E. traquaira Stiirtz (citations as above). Lower Devonic of Bundenbach, Germany.
Genus MEDUSASTER Sturtz.
Medusaster Sttirtz, Paleeontographica, vol. 36, 1890, p. 229; pl. 31, figs. 34, 35; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 54, 73. A form with from 12 to 15 rays. Thought to have relationship with living Solaster. Genoholotype and only species.— M. rhenanus Stirtz (citations as
above). Lower Devonic, Bundenbach, Germany. Cac. No. 59385, U.S.N.M.
PALEOZOIC OPHIURIDS.
A great deal has been written about these animals, but in general the true structure of some of them was not known until very recently. Authors have described these delicate and generally poorly pre- served fossils in such broad terms that a complete restudy of all of the material is required before it can be said that most of the genera or even the species are established. The way has been successfully blazed by Schéndorf in Europe, and his methods of study and results need to be applied to the American fossils. It was the writer’s hope to do this, but it is now plain that his present duties will prevent his doing so.
In general it may be said that but few Paleozoic so-called ophiurids are true Ophiuroidea. They are ophiurid-like animals, with open ambulacral furrows, but without the essential characters of the Asteroidea. Nor are they transitional in structure between the Asteroidea and Ophiuroidea. Therefore Schéndorf has separated them under the term Auluroidea. It seems to the writer that they originated in the Asteroidea early in the Ordovicic in some crypto- zonian stock near Urasterella, with large and square ambulacralia. (Stenaster and Tetraster are probably true aulurids.) Out of the Aulu- roidea, probably in late Devonic time, arose the true Ophiuroidea.
The essential differences between the Auluroidea and Ophiuroidea will become plainer to the student after a study of the text and figures presented in this work.
REVISION OF PALEOZOIC STELLEROIDEA. 21s
Subclass AULUROIDEA.
Auluroidea ScubNvorr, Palxontographica, vol. 67, 1910, p. 60; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 234, 247, 251.—SpENcER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontogr. Soc. for 1913), 1914, pp. 24, 48.
Protophiuroidea and Euophiuroidea Souias and Souias, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, pp. 214, 222.
Auluroidea are Paleozoic brittle-stars, with a more or less well- developed central disk, whose border between the rays is more often concave than convex; in otherwords, star-shaped. The rays appear al- ways to be five in number, simple, long and slender, and more or less sharply marked off from the disk as appendages. This means that the body cavity does not extend from the disk into the rays as in Aster- oidea. On the actinal side the rays
have open ambulacral furrows with the ambulacralia never anchylosed into vertebre; they are arranged in two columns, the pieces of which are either alternate or opposite one another.
Original definition.—‘ The ambu-
Fig. 12.—A SECTION THROUGH THE ARM OF AN ASTERID, AFTER SCHONDORF. A, AMBULACRA- LIA; Ad, ADAMBULACRALIA; Amp, AMPULLE; D, DORSAL SKELETON; F, PODIA; ipl, ACCES- SORY OSSICLES; Mo, ATTACHMENT FOR UPPER LONGITUDINAL MUSCLES; Mol, UPPER TRANS- VERSE MUSCLE; Mu, ATTACHMENT FOR LOWER LONGITUDINAL MUSCLE; Mu, LOWER TRANS- VERSE MUSCLE; Mv, VERTICAL MUSCLE; Ro, UPPER MARGINALIA; Ru, LOWER MARGINALIA;
: . Wr, RADIAL WATER-VESSEL. lacral water-vascular system les in
a circtilar canal that is situated wholly within the ambulacralia medi- ally between the adjoming columns of ossicles. From it diverge short side branches that either partially penetrate the substance of the individual ambulacrals, or lie in the suture between adjoining ambulacrals; in either case they extend into the ventrally open, broad ambulacralfurrow. Ambulacrals free, not coossified, those of adjoining columns either alternate or opposite, but always di- rectly opposite the adambulacrals. Ambu- lacrals ventrally composed of a medially situated, internally concavely hollowed-out body, which, as the plates of the two columns are normally united, forms the medial ambu- lacral canal; and of a lateral process extend- ing to the adambulacrals, with depressions on both sides of it in the ventral surfaces of
Fic. 13.—A SECTION THROUGH THE ARM OF A TRUE OPHIURID, AFTER SCHONDORF. Bs, VENTRALSHIELD; C,cutis; F,popia; L, BODY CAV- ity; N, NERVE-RING; 0Zm, uZm, UPPER AND LOWER INTERMEDIARY VERTEBRAL MUSCLES; Rs, DORSAL SHIELD; Ss, LATERAL SHIELD; W, VERTEBRE; Wr, RADIAL WATER-
VESSEL. the ambulacrals and adambulacrals [see fig. 14]. [These large lateral depressions are not podial openings through
or between the plates as in asterids, but appear to be cavities for the ampullie or for these and podial insertions. Dorsally the ambulacrals
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are covered with spines and tubercles.] Disk with concave, or con- vex (?) margins, with or without marginal ossicles. When the latter are present, they never extend along the rays, but are wholly re- stricted to the disk. The rays on both sides are margined by the adambulacrals. Ventrally the rays have broad open ambulacra! fur- rows, bounded laterally by the adambulacrals. A typical mad- reporite [probably always] lies in one of the ventral interradii.
“The group [subclass] is re- stricted to the older Paleozoic.”
Remarks.—This subclass of
Fic. 14.—A SECTION THROUGH THE ARM OF AN AULURD, Stelleroidea appears to be an in-
WITH ALTERNATING AMBULACRALIA, AFTER SCHON- “I DORF. A, AMBULACRALIA OF THE DORSAL AND VEN- dependent development whose
TRAL SKELETON; Al, VENTRAL EXTENSION OF THE structure partakes of that of
AMBULACRALIA; Ad, ADAMBULACRALIA = LATERAL Atal Se SHIELDS OF OPHIURIDS; J’, PODIA, ON LEFT THE CANAL the Asteroidea and the Op hiu
PASSES THROUGH THE PLATE, ON RIGHT THE PLATE Is TOldea, though more like the DISSECTED DOWN TO THE CANAL; Wr,INTERSKELETAL Jotter, The Auluroidea agree RADIAL WATER-VESSEL. . . . . o with the asterids in having open ambulacral furrows, and a true madreporite, which is, however, ven- trally situated, but otherwise the class is more like the ophiurids, since the body cavity does not extend into the rays as in true starfishes. However, the water-vascular canal in the Auluroidea does not lie outside of the ambulacrals as in the Asteroidea, but within these ossicles along the mid-line of the ambulacrum in a canal that is cut out of the sides of adjoming ambulacral columns. On the. other hand, the Ophiu- roidea have the am- bulacralia coossified and modified into vertebral ossicles;
there are no open
fe . Fias. 15 AND 16.—VENTRAL AND DORSAL ARM STRUCTURE OF AULUROIDEA, ambulact al fu rrows, WITH THE AMBULACRA ALTERNATING. SCHEMATIC, AFTER SCHONDORF. and the entire Trays A, AMBULACRALIA; Al, VENTRAL EXTENSIONS OF AMBULACRALIA; Aq,
are covered by four ADAMBULACRALIA; FS, PODIAL CAVITIES. columns of shields or by an integument more or less studded with calcareous plates and granules.
It appears that the Auluroidea all have dorsally four columns of plates, of which the two medial ones are the most prominent. These are undoubtedly the dorsal aspect of the thickened ambulacrals. Outside of the disk they are usually convex and more or less orna- mented with granules, but within the disk are less prominent and take on other expressions, commonly with concave surfaces. The plates outside of these margin the rays and are the adambulacrals; while in some forms they are prominent and tuberculate, usually they are made up of narrow vertical pieces that bear spines along the ventral or only the distal ventral edge.
a cA AL kab
REVISION OF PALEOZOIC STELLEROIDEA. 915
The Auluroidea can be divided into two orders on the basis of whether the ambulacrals on each side of the median line are arranged alternately (the Lysophiure), or are opposite to one another (the Streptophiure). The following classification is a modification of the one offered by Gregory in 1897, and his work was in turn a modification of that of Bell in 1892.
“After the present work was written, its author first became aware of the works of Sollas and Sollas, and Spencer. The reader should consult those papers for important studies on the Auluroidea.
Order LYSOPHIUR Gregory.
Encrinasterix BRONN (part), Klassen u. Ordnungen d. Tierreichs, vol. 1, 1859, p. 287.—Scu6nporr, Paleeontographica, vol. 57, 1910, p. 61.
Ophio-Encrinasterix Sttirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 198.—Scu6Nnpvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 234, 237.
Lysophiure Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1030 (contains Protasteridze and Palseophiuride); Treat. Zool., vol. 3, Echinoderma, 1900, p. 274.—Sotzas and Soxuas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 223.
Ophiurasterie ScHONDORF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 251.
Auluroidea in which the ambulacral ossicles of adjoining columns are alternate to one another. The individual plates are separate and not coossified into vertebre.
Remarks.—The Lysophiure are Paleozoic or primitive Auluroidea, that is, ophiurid-like animals, with wide and open ambulacral furrows in which the ambulacralia are free and alternately arranged. The ambulacralia are common to the actinal and abactinal sides.
This order contains the following families:
Protasteride. Have boot-shaped ambulacralia ventrally.
Paleophiuride. Have subquadrate ambulacralia ventrally.
Encrinasteride. Have boot-shaped ambulacralia ventrally and large disks that are bordered by marginalia.
Family PROTASTERIDZ Miller.
Protasteride Mutter, N. Amer. Geol. Pal., 1889, p. 216.—Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1031; Treat. Zool., vol. 3, Echinoderma, 1900, p. 274.—Parks, Trans. Canadian Inst., vol. 8, 1908, p. 366.
Palxophiomyxide Srtrrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 202.
“Lysophiure with boot-shaped ambulacral ossicles, each composed of a ‘body’ in the median line of the arm, and a lateral ‘wing’ at right angles to it” (Gregory). There is either a well-marked scale-covered or granular disk, and five flexible arms. The adambulacral plates are rather stout, with many lateral spines.
216 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Schéndorf states that Gregory’s family Paleophiuride has no value and is to be merged into the one under discussion. The reasons for this are given beyond under the former family heading.
The family contains:
Teeniaster Billings. Alepidaster Meek. Eophiura Jackel. Gregorvura Chapman. Bohemura Jaekel. Bundenbachia Stiirtz. Paleura Jaekel. Palzophiomyza Stirtz.
Protaster Forbes. Genus TAZ NIASTER Billings. Plate 36, figs. 1-3.
Tzniaster Brttinas, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 80.— CHAPMAN, Canadian Journ., n. ser., vol. 6, 1861, p. 517.—Wriaut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, pp. 24, 34.—Ha.t, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 300; rev. ed., 1868=1870, p. 338.—Zrrret, Handb. Pal., vol. 1, 1879, p. 445.— Stirtz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 150; Paleeontographica, vol. 32, 1886, pp. 78, 88.—MititEeR, N. Amer. Geol. Pal., 1889, p. 285.—GreGory, Geol. Mag., dec. 3, vol. 6, 1889, p. 26.—Sritirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 20.—J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 188.—Greeory, Proc. Zool. Soc. London for 1896, 1897, p. 1035; Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.—SpENcER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pp. 8, 19.
Teniura GREGoRY, (not Txniura Miller and Heule 1837, sting-ray), Proc. Zool. Soc. London for 1896, 1897, p. 1035.
Original description of Teniaster—‘ Generic Characters.—Body deeply stellate; no disk [there is a disk] or marginal plates; rays long, slender, flexible, and covered with small spines; two rows of large ambulacral pores; adambulacral plates elongated and sloping outward so that they partly overlap each other; ambulacral ossicles contracted in the middle, dilated at each end. Generic name from tania, a riband.”’
Genolectotype (the first species of Billings is here selected as the genolectotype).—Palzxocoma spinosa Billings.
Remarks.—Hall restudied the type-material of Teniaster and records his observations as follows:
“Tn reviewing the characters of Protaster and Eugaster, I became satisfied that there was an intimate relation between these and Txniaster of Billings, and in order to satisfy myself on this point, Ihave * * *_ received from Sir William E. Logan, permission to examine specimens of Txeniaster spinosus and T. cylindricus.
“An examination of the specimen illustrated in fig. 3 (ut sup.) reveals what I conceive to be a disk not at all unlike the disk of Prot- aster, but less extended than in the Lower Helderberg species. The structure of the ray is precisely of the same character as the ray of
REVISION OF PALEOZOIC STELLEROIDEA. ST
that species which I have named Protaster forbesi, the proportions of plates and relations of parts showing specific differences.”’
“Mr. Billings remarks, under the description of 7. spinosus, that ‘the ambulacral ossicles appear in some places to alternate with each other, but this is owing to a distortion; those on one side of the furrow are opposite to those upon the other.’
‘“‘Now the specimen of this species which I have examined, and which I suppose to be the one figured upon Plate X, figures 3a, b, has the ambulacral plates alternating * * *.
“In the specimen of TJ. cylindricus examined the ambulacral plates are less distinctly alternate, but the relation of the adam- bulacral plates and the pores are the same as in the other form. Not having seen the specimen showing the dorsal view, figure 4a of plate X, I can only remark that the structure of the rays is very similar to that of Protaster.”’
Without restudying the type-material of Y'eniaster, or paying attention to Hall’s statements that 7. spinosus has what he con- ceived ‘‘to be a disk not at all unlike the disk of Protaster,”’ Gregory (1897) regarded Txniaster as a Cryptozonia starfish and made of Billings’s second species, 7’. cylindricus, a new genus, Tzniura. The latter he correctly refers to the primitive ophiurids. Under these circumstances it is desirable to repeat here what Gregory wrote about Texniaster.
Teniaster “was described as diskless, which in respect to the type species 7’. spinosus is correct. In that species the oral skeleton consists of five pairs of large adambulacrals, as in ordinary Asterids. The affinities of the true Tzniaster appear to me to be with such forms as Palexaster ruthvent [= Urasterella ruthveni]. It is asteroid in the oral armature, in its alternately arranged ambulacral ossicles, and in the absence of a disk. I therefore consider Txniaster a genus of Asteroidea. The second species placed by Billings in this genus has, however, a well-marked disk, and has the oral armature com- posed of five pairs of Ophiuroid syngnaths. It must, therefore be included among the Ophiuroidea.”’
To adjust this matter, the writer restudied the genotype of Txniaster at Ottawa (two specimens, No. 1404, the originals of figures 3a—3d of Billings’s Plate X). There can be no doubt that we have here a genuine lysophiurid. There is a small disk present in the individual figured as 3a and 3b, but it is not one with a round outline, as in typical ophiurids, but is concave along the margin between the rays. Actinally this disk is abundantly covered with prominent but slender spines.
The ambulacrals are distinctly alternate throughout the rays and ap- pear as in the sketch presented on page 218; this condition is not due to distortion or other causes. The side plates are narrow, and each
918 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
bears three spines (see fig. 17B); toward the mouth the two columns diverge far more than one would assume from the original figure, and in consequence there are long and slender syngnaths and not the asterid-like mouthpieces figured in the illustration. (See fig. 17C.)
if € ad
Fic. 17.—DIAGRAMS OF TE#NIASTER SPINOSUS (BILLINGS). A, TO SHOW THE SPINOSE DISK WITH CONCAVE sIpES. B, ACTINAL PLATE ARRANGEMENT: @, AMBULACRALS; ad, ADAMBULACRALS OR SIDE PLATES, WITH THEIR SPINES. C, MOUTH PLATES: @, AMBULACRALS; 8, SYNGNATH.
The specimen of figures 3¢ and 3d is too poorly preserved to add anything further. Associated with these types there is another and much larger specimen with a well-marked disk, of which Billings said nothing in his original description. This form is clearly of another species (probably 7. cylindricus), and is mentioned here so that other workers will not confound it with the original material of T. spinosus.
In 1900 Gregory referred Txniaster to the asterid family Tzenias teridz, and placed here as well the unrelated genera Stenaster, Salter- aster, and Urasterella. From what has been stated above it is plain that Txniaster can not be closely related to the cryptozonian genus Urasterella, since the latter has an abundance of narrow ambulacralia, asterid in type, while these ossicles in the former are far fewer in number and of the form seen in other and related Lysophiure. It is very probable that Teniaster arose in the same stock that gave rise to Urasterella and Stenaster, but the former genus is clearly one of the aulurids.
In 1896 Gregory took out of Tezniaster the second species of Billings (7. cylindricus) and based on it the new genus Teniura. As will be seen, this name can have no standing, as the generic char- acters are those of Tzniaster, and, further, the name is preoccupied since 1837.
Thinking 7. cylindricus most closely related to the primitive ophiurids Palzophiura and Stirtzura, Gregory defined Teniura as follows:
‘Diagnosis: Paleophiuride with a small pentagonal disk, not bounded by marginal ossicles. The ambulacral furrow is broad. The oral skeleton is conspicuous and the syngnaths each composed of two separate pieces. The two jaws of each oral angle are closely attached; the mouth frames are separated, and each of them is a short, thick, slightly bent bar.”
REVISION OF PALEOZOIC STELLEROIDEA. 219
Genotype and only species.—Palzxocoma cylindrica Billings.
“Remarks: This genus differs from Palzophiura by the absence of marginal ossicles from the disk, and from Sturtzura by the smaller size of the disk and the form of the syngnaths. In Sturtzura the jaws end bluntly against a jaw plate, whereas in Txniura they appear to taper to a point and have no jaw plate.”
The two cotypes of 7’. cylindricus (1405a) were lost for many years, but have recently been rediscovered in the collections at Ottawa. In addition, there is another specimen in that Museum under this name, and it is probable that it was so identified by Billings (No. 1405). This was the only specimen studied, and its generic characters agree very well with the originals of the cotypes (figs. 4b and 4c of pl. X), and appear to be in harmony with the genotype of Txniaster. The only important difference is that here the ambulacralia are directly opposite one another, and not slightly alternating, as in T. spinosus (see fig. 18), a difference, it seems to the writer, not in itself alone worthy of being the base of a new genus distinct from Tzniaster.
Teniaster has the following species:
T. spvnosus (Billings). Lower Trenton.
T. cylindricus (Billings). Trenton.
Lf. schohariz Ruedemann. Upper Trenton.
T. elegans Miller. Richmondian (Waynesville). T. meafoadensis Foerste. Richmondian.
TAZENIASTER SPINOSUS (Billings). Plate 36, fig. 1; text fig. 17.
Palxocoma spinosa Biuuines, Geol. Surv. Canada, Rep. Progress for 1853-1856, 1857, p. 292.
Texniaster spinosus Bruurnes, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 81, pl. 10, figs. 3a-3d.—Mitzr, N. Amer. Geol. Pal., 1889, p. 285, fig. 439.
Revised description by Bullings.—‘‘The specimens collected are about seven lines in diameter; the rays linear-lanceolate, one line in width at the base, and covered at the sides with numerous small spines.
‘“‘In the view of the enlarged specimen (pl. X, 3B), the ambulacral ossicles appear in some places to alternate with each other, but this is owing to a distortion. Those on one side of the furrow are oppo- site those upon the other. The adambulacral plates are elongated, and so placed that the outer extremity of the one lies upon the inner extremity to the next. The rays are flexible.”
For remarks on this species, see the discussion under Teniaster.
Formation and locality —Two specimens from the Lower Trenton, Falls of Montmorency, east of Quebec, Canada. The original of figures 3a to 3d is in the Victoria Memorial Museum, Ottawa (No. 1404).
220 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
TENIASTER CYLINDRICUS (Billings). Plate 36, figs. 2, 3; text fig. 18.
Palzxocoma cylindrica Bruuines, Geol. Surv. Canada, Rep. Progress for 1853- 1856, 1857, p. 292.
Tzniaster cylindricus Biturnes, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. $1, pl. 10, figs. 4a-4c.—Wrieut. Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, p. 34.—Parks, Trans. Cana- dian Inst., vol. 8, 1908, p. 371.
Txniura cylindrica GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 1035.
Lapworthura cylindrica Parks, Trans. Canadian Inst., vol. 8, 1908, p. 371.
Original description—‘‘One inch and a half in diameter; rays five [very flexible], covered with spines, subcylindrical, regularly rounded on the upper side, flattened on the lower, about one line in width at base, and regularly tapering to an acute point.”
Formation and locality—In the Tren- ae = ton limestone at Ottawa, Canada. The Fic. 18.—D1aGRam or acTIvaL Ray-ptates COtypes (1405qa), along with a third
OF TENIASTER) CYLINDRICUS BILLINGS. specimen (1405), are in the Victoria
@, AMBULACRAL; ad, SIDE PLATES. ¥ Memorial Museum at Ottawa.
TZENIASTER SCHOHARIZ Ruedemann.
Txniaster schoharix RUEDEMANN, Bull. N. Y. State Mus., No. 162, 1912, p. 88, Die sete de
Original description.—The holotype ‘‘is small, the arms about 15 mim. long, and it is without a disk. The arms are slender and flexible, about 1.3 mm. wide at the base, and almost as high in lateral view, originally probably cylindrical. The ventral view shows a straight or slightly zigzagged ambulacral canal, and on both sides of this squarish depressions surrounded by the ambulacral and adambulacral ossicles, the covering lower arm plates not being retained if they existed. The inner (ambulacral or vertebral) ossicles appear as narrow and outwardly curved ridges, the outer or adambulacral ossicles as ridges bent in the opposite direction with a projection in the middle of the outer arch. The ambulacral ossicles are not directly opposite nor regularly alternating, but those of the right side on the ventral view advanced about one-third the length of the ossicles beyond those of the other side.
“The lateral view of one other arm exhibits the ossicles as ver- tical bars, that are thickened at both ends resembling vertebre and terminating at the dorsal side with a flat surface and forming there an apparently continuous layer. They appear almost twice as wide as the intervening spaces. The dorsal surface bears bundles of obliquely forward directed spines, one bundle corresponding to each ossicle. These spines appear in the right arm to proceed from
REVISION OF PALEOZOIC STELLEROIDEA. ook
small spine-bearing plates attached to the adambulacrals, as in the closely related Bundenbachia. On one arm two bundles are seen to proceed from each segment, one oblique, the other vertical to the arm. The oral skeleton consists of stout, bifid pieces, much resembling the oral pairs of adambulacrals of the genotype.”
Formation and locality—Upper Schenectady formation, the eastern shale phase of the Upper Trenton limestones. From near Schoharie Junction, New York. The holotype is in the New York State collection at Albany.
TZENIASTER ELEGANS Miller.
Tzniaster elegans MituER, Journ. Cincinnati Soc. Nat. Hist., vol. 5, 1882, p. 41, pl. 1, figs. 6-6c—J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 139.—Parks, Trans. Canadian Inst., vol. 8, 1908, pp. 365, 371.
Protaster elegans Parks, Trans. Canadian Inst., vol. 8, 1908, p. 368.
Original description.—“ This species is founded upon more than 30 specimens occurring on a single slab, but showing only the ventral side, with the exception of the ends of some of the rays.
“The body is deeply stellate, and the rays long, slender, and flexible, and margined on either side with a row of spines.
“From the length of some of the rays, a complete specimen, properly spread, would probably have a diameter of an inch and a quarter, or more. The rays taper to a sharp point, are rounded on the dorsal side, and margined on the ventral side by a row of spines, one spine arising from each plate. Only two rows of plates seem to form the dorsal side of aray. The ventral side of each ray is marked by a furrow in the middle, separating two series of plates or ossicles. These plates are a little longer in the direction of the ray than wide, and alternately break joints at the middle, where they are slightly contracted.”
Formation and locality—This extraordinary slab is in the Harris collection of the United States National Museum. It was found near Waynesville, Ohio, in the Richmond formation of the Ordovicic period.
Cat. No. 40878, U.S.N.M.
TANIASTER MEAFORDENSIS Foerste.
Texniaster meafordensis ForrstE, Bull. Sci. Lab. Denison Univ., vol. 17, 1914, p. 326, pl. 4, figs. 5-7.
The reference to this species is inserted as this book is going through the press. The form appears to be common in the lowest Richmon- dian on Workman Creek, three miles southeast of Meaford, Ontario, Canada. The types are probably in the Victoria Memorial Museum, Ottawa, Canada.
222 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genus EOPHIURA Jaekel. Text figs. 19, 20. Eophiura JAEKEL, Zeits. geol. Gesell., vol. 55, 1903, Protokol, p. 14 (107), figs. 1, 4.
Genoholotype.—Eophiura, species not named. To give this genus proper standing according to the rules of nomenclature, the form is here named E. bohemica, new species. It is the only species of the genus, and occurs in the Ordovicic (D,) at Osek, Bohemia.
The genus is not defined in the regular manner, but from the general discussion and the illustrations the following has been made out: Rays outside of the disk, apparently petaloid in form, with wide-open am- bulacral furrows, having narrow alternating ambu- lacralia that are --shaped, with the podial openings excavated on each side of the lateral extensions. The adambulacrals are very large, drawn out lat- erally,rectangular, lie hori- zontally, and in no way resemble the side plates of typical ophiurids, or, for that matter, even the Lys- ophiure. The lateral edges of these ossicles are slightly elevated, tubercu- lated, and each bears about four long and very slender spines. Inside of the disk Fig. 19—END OF A RAY OF EOPHIURA BOHEMICA, MUCH EN- the adambulacrals are nar-
LARGED, AFTER JAEKEL. @, AMBULACRALIA; ad, ADAMBULA- TOW and stand vertically cus Af m0 oF font; ity attaas METEACN OF ys in Paleozoic ophiurids; the columns first diverge and then converge in the mouth area. The two proximal pieces of each column make the adambulacral mouth extensions, with the terminal ossicles of adjacent columns side by side but not coalesced, forming the syngnaths. The two most proximal ambulacrals rapidly decrease in size, enlarging the mouth area, with none of these ossicles on each side of the two final adambulacrals.
The disk seems to be small, with concave interbrachial sides. Actinally these areas are covered with scale ossicles. Madreporite ventral, in the outer and lateral part of an interradius. Immediately outside of the syngnaths occur interradially two small ossicles, reminding one of vestigia! inframarginalia.
REVISION OF PALEOZOIC STELLEROIDEA. 923
Genus BOHEMURA Jaekel. Text fig. 21.
Bohemura JAEKEL, Zeits. geol. Gesell., vol. 55, 1903, Protokol, p. 18 (111), fig. 6. This genus, like the foregoing, is not defined in the regulation way. Jaekel’s fine drawing shows that it is closely related to Hophiura, differing mainly in that the rays do not end bluntly, but have slowly tapering whip-like terminations. These ends are of course ontoge- netically young and reveal the progressive ray development. Here
Fig. 20.—ORAL SKELETON OF EOPHIURA BOHEMICA, AFTER JAEKEL. @, AMBULACRALIA; ad, ADAMBU- LACRALIA; Ma, MADREPORITE AMONG THE SCALE PLATES.
the rays are made up of overlapping and alternating adambulacrals that distally have no ambulacral grooves. Gradually an ambulacral groove is developed and it becomes rapidly wider as one examines the rays more and more proximally, and the adambulacrals turn over and flatten out, finally making the great open ambulacral furrows. The illustration here reproduced, figure 21 on page 224, will show the generic characters as drawn by Jaekel.
Genoholotype and only species —B. jahni Jackel. Ordovicic (D,) at Zahorzan, Bohemia.
Genus PALAHZURA Jaekel. Text fig. 22. PalzuraJAEKEL, Zeits. geol. Gesell., vol. 55, 1903, Protokol, p.16(109)-17(110), fig. 5.
Genoholotype-—Palzura, species not named. No species is again mentioned, nor is it stated that the generic name is new. ‘To give the name standing, the form figured is here named P. neglecta, new genus, new species. It occurs in the Ordovicie (D,) of Bohemia; the exact locality is not given, but may be Osek.
50601°—Bull. 88—15——15
224 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Jaekel here again fails to diagnose his genus, but some of the characters can be clearly made out from his excellent drawing. The disk is small and tends to have convex interbrachial areas. So far as the oral disk area is concerned, the general structure is that of Eophiura, with this marked difference—the opposite and asterid- like ambulacralia of the rays do not vanish proximally as in that
Fig.21.— VENTRAL VIEW OF A RAY OF BOHEMURA JAHNI, ENLARGED ABOUT X 2, AFTER JAEKEL. a, AMBULACRALIA; ad, ADAMBULACRALIA WITH THEIR LATERAL EXTENSIONS; adm, SYNGNATHS.
genus but crowd over and finally rest wholly upon the adambulacrals, and end against the distal edges of thesyngnaths. These are made up of the coossified terminal adambu- lacral ossicles.
Genus PROTASTER Forbes.
Text fig. 23.
Protaster ForsBEs, Mem. Geol. Surv.
United Kingdom, dec. 1, 1849, pl. 4, pp. 1-2; in McCoy, British Pal. Foss., 1851, p. 60.—MurcuHIson, Siluria, 1854, p. 221, fig. 39-4— SALTER, Rep. Twenty-sixth Meet., Brit. Assoc. Adv. Sci., Notices and abstracts, 1857, p. 76; Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, pp. 325, 330.— Hat, Nat. Hist. N. Y., Pal., vol. 3, 1859, p. 134.—SatsEr, Ann. Mag. Nat. Hist., ser. 3, vol. 8, 1861, p. 484.—Wriaut, Mon. Brit- ish Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleontogr. Soc. for 1861), 1862, pp. 23, 31.—Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 293; rev. ed., 1868=1870, p. 335.—QUENSTEDT, Petrefacten- kunde Deutschlands, vol. 4, 1876, p., 133, pl..95 fig. 1. —_Srunra, Ne Jahrb. fiir Min., etc., 1886, vol. 2, pp. 148, 150.—Greeory, Geol. Mag., dec. 3, vol. 6, 1889, p. 26.— Srirtrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 18.— J. F. James, Journ. Cincinnati Soc.
Nat. Hist., vol. 18, 1896, p. 137 —Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1031, fig. 1—WuipBorne, Paleontogr. Soc., 1898, p. 206.—Parks, Trans. Canadian Inst., vol. 8, 1908, pp. 363, 366.—ScHOnporr, Jahrb. nas- sauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 238.—Soias and SoLtas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 223.—SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontogr. Soc. for 1913), 1914, p. 35. Encrinaster (part) HarcKe1, Gen. Morphologie, vol. 2, 1866, p. 1xvii (no definition).
Also see Stiirtzura.
REVISION OF PALEOZOIC STELLEROIDFA. 995
Original description.—‘ (Order Ophiuride. Family Euryales.) Body circular, covered with squamiform plates; genital openings in the angles of junction of the arms beneath; arms (simple) formed of alternating ossicula.”’
Genoholotype.—‘ Species Unica. Protaster sedgwickii. Forbes.”
Original description of P. sedgwickii.—‘ The disk is circular, and shaped like that of an Ophiura. The arms are five in number, very narrow, equidistant, and similar.
“The upper and under surfaces of the disk were covered by small, similar, more or less regular, polygonal or crescentic plates, imbri- cated in scale-fashion, and having punctated surfaces. Those of the under side of the body are smaller and more regular than those of the upper. The mouth is cen- tral, and rather small in proportion to the disk. The buccal ap- paratus is composed of ten parts or proc- esses, arranged in pairs; half of each springs from the origin of each arm in a diverging manner, and meets the corre- sponding half toform a lanceolate tooth- like projection, deeply indenting the cavity of the mouth. Of how many separate ossicles each of the buccal processes was composed the specimen affords but very indis- tinct indication. Theyseem to affect a slightly falcate form at their extremities. The arms were composed of alternating, somewhat quadrate ossicula, the sides of which were deeply indented supe- riorly, in order to form spiniferous crests. The spines were appar- ently short, and not equal in length to the length of an ossicle, obtuse, and few in a row. The under surfaces of the brachial ossicula were not indented laterally. The central portions of the upper surfaces of the brachial ossicles were hollowed out slightly, and the sutures between them deeply impressed. About 12 of the brachial ossicles were imbedded in the disk, and the parts of the dorsal surface of the latter, corresponding to the arms and central skeleton, do not present traces of scales, a feature seen in existing Euryales.
Fig. 22.—ORAL SKELETON OF PALZURA NEGLECTA, MUCH ENLARGED, AFTER JAEKEL. dad, AMBULACRALIA; ad, ADAMBULACRALIA.
226 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
‘‘The dimensions of Prof. Sedgwick’s specimens are as follows: “Breadth of disk, 0 8/12ths inch. “Average breadth between arms, 0 5/12ths inch. Breadth of an arm, at its junction with the body, 0 1/12th inch.
“Locality and geological horizon.—Silurian, from Ludlow rocks at Docker Park, near Kendal, Westmoreland (specimen figured), associated with Hncrinites, and at Benson Knot, also near Kendal, in hard sandstones, full of characteristic Ludlow fossils.”
Gregory restudied this genus and in 1897 defined it as follows: ‘‘Protasteride with a well-marked disk; long, tapering, very flexible arms. Some of the adambulacral ossicles are Y-shaped. Scales of the disk fairly large. Type species.—Protaster sedgwickii, Forbes.”
Gregory remarks that ‘‘Forbes’s figures of the arm-structures are
not satisfactory,” 4 J) Jd GC And
MQ and their apparent S \ ie Q gk nature is shown in VIC a5 Sh) figure 23 as drawn Vig J KF MK IRES by the former. hs oy This illustration Fic. Sy AER AND ADAMBULACRALIA OF PROTASTER an eeeer shows each set of AFTER GREGORY. @, NEAR THE DISTAL END; 0, IN THE MIDDLE; C, AT ambulacralia dif- THE PROXIMAL END. THESE DIFFERENCES ARE DUE TO PRESERVATION. ferently, a condi- tion thought to be due to preservation and adhering rock rather than to structure (see fig. 28, on p. 242). Madreporite probably abactinal in position. In regard to the term Encrinaster, see Encrinaster (Aspidosoma), page 242. Protaster has the following species: P. sedgwickit Forbes. Ludlow of England. P. biforis Gregory. Wenlock of Wales. P. groomé Sollas and Sollas. Ordovicic of England. P. (2) whiteavesianus Parks. Black River. P. (2) salteri (Salter). Ordovicic of Wales. P. (2) stellifer Ringueberg. Rochester.
PROTASTER BIFORIS Gregory. Text figs. 24, 25. Protaster biforis GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 1032, figs. 2,3 on p. 1033.—Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 238.
Original description.—‘‘Disk fairly large; interbrachial outlines coneave. The syngnaths are simple, prominent, and stout. The ambulacral ossicles consist of a thick body and a stout curved wing. The distal margin of the ossicles is notched by a depression for a ventral musele-field, which also cuts into the proximal margin of the adjoining ossicle. Owing to these muscular depressions the arm has apparently two series of pores.
REVISION OF PALEOZOIC STELLEROIDEA. 92%)
‘“The adambulacral ossicles are massive and taper slightly to their distal ends; they are closely attached and form a regular series of marginal plates.
‘‘Arms very flexible.
** Dimensions: Pancrloblon pert. ATM. 2. tic. tos cc SW ies sup ded. wate do Sade alex dee 18 mm.+2 WMismeter of armat the bases so. .22- lee. nee 2. < oe cece Sede eceeene 2.5 mm. Diameter of arm near the distal end.....................--...---------- 1 mm. Drameter Of Mouth 2. eens 2 bts cc oes cece edeseeeceees-- 125 mm, ee renova tsa: se eck Romo Scent hanles Mere ed god Hees nae 1 mm. Width of ambulacral furrow at edge of disk...............22....------ 1.25 mm.
“PDistribution.—Wenlock Shale, Castell Dinas, Bran, near Llan- gollen,’’ Wales. Museum Practical Geology, London.
24 Figs. 24 AND 25.—PROTASTER BIFORIS. AFTER GREGORY. 24, AMBULACRALIA AND ADAMBULACRALIA, 25, @, OUTLINE OF THE DISK AND ARMS; b, A PAIR OF SYNGNATHS.
PROTASTER GROOM I Sollas and Sollas. . Protaster groomi Soutias and Souuas, Philos. Trans. Roy. Soc. London, ser. B vol. 202, 1912, pp. 223, 224. Occurs in the Middle Ordovicic of Shropshire, England.
PROTASTER (?) WHITEAVESIANUS Parks. Protaster whiteavesianus Parks, Trans. Canadian Inst., vol. 8, 1908, p. 368, figs. 1-6.
This is a large form with a disk 15 mm. across and with rays 60 mm. long. It is described in too much detail to quote here. The ambula- cralia are distinctly alternate and boot-shaped.
Formation and locality—In the Lower Trenton (Kirkfield), at Kirkfield, Ontario, Canada. The cotypes (five) are in the University of Toronto (No. 638 T.).
PROTASTER (?) SALTERI (Salter).
Ophiura salteri Sauter and Sowersy, Quart. Journ. Geol. Soc. London, vol. 1. 1845, pp. 9, 20 (table) (nomen nudum).
Protaster salteri Wriaut, Mon. British foss. Echinod., Oolitic, vol. 2, pt. 1 (Palwon- togr. Soc. for 1861), 1862, p. 33 (nomen nudum).—SarrerR, Mem. Geol. Surv. Great Britain, vol. 3, 1866, p. 289, pl. 23, fig. 3 (is inclined to refer it to Txniaster).—Parxks, Trans, Canadian Inst., vol. 8, 1908, pp. 364, 367.
Formation and locality—The holotype is from the Ordovicic, near Cerrig-y-Druidion on the Holyhead road, Wales.
228 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
PROTASTER (?) STELLIFER Ringueberg.
Protaster stellifer RINGUEBERG, Bull. Buffalo Soc. Nat. Sci., vol. 5, 1886, p. 7, pl. 1, fig. 2.
Generic relations not established.
Original description —“ Disk of medium size, flat, circular, slightly flexible, distinct from the rays on the dorsal side, and has on that side a quinque-dentate, stellate, central elevation, which again has a central, stellate depression of about one-half the lateral extension of the stellate elevation upon which it is impressed. The points of the star-like figure are opposite the several rays and extend about two-thirds across the disk.
‘‘Surface finely granulose. Rays slender, almost imperceptibly tapering in the upper half of their known length; rounding on the dorsal side, with two rows of regular, quadrilateral, alternating [ambulacral] plates which can with difficulty be made out, and which have a fine granulose [integumentary] surface resembling the surface of the disk; opposite each transverse suture there is a corresponding linear depression across the surface of the opposite plate on the other side of the median suture, which at first sight gives the impression that the ray is composed of opposite plates of only one-half the real length.
“Ventral side with ten short, oral plates which are slightly sepa- rated below, and meet at the discal surface, where they are rounded.
‘“Ambulacral series long, regularly quadrilateral; alternately arranged.
‘“Adambulacrals indistinct in the only specimens found showing the ventral surface.
‘‘Marginal series slightly imbricating; spiniferous; spines rather short.”’
Formation and locality—Three specimens were collected in the Rochester shale of the Siluric at Lockport, New York. They are in the author’s collection. Two other fine specimens were found by C. J. Sarle at Lockport and are now at Yale University. Another good specimen is in the Walker collection of the University of Toronto (No. 1007); it was found at Grimsby, Ontario.
Genus ALEPIDASTER Meek. Plate 36, fig. 4; text fig. 26.
Alepidaster MrEK, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 275; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 68, at end of specific description. Protasterina Unricu, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 95.—J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 139 (genoholotype, P. fimbriata Ulrich). Original description—“The only specimen I have seen that is certainly known to belong to this species [P. ? granuliferus] is very
REVISION OF PALEOZOIC STELLEROIDEA. 229
imperfect, being merely an incomplete disk, and the inner ends of the rays. It does not conform to the characters of Protaster given in Prof. Forbes’s diagnosis, in all respects, since its disk, especially on the upper side, is covered by an integument composed of a vast number of very minute grains of calcareous matter, instead of dis- tinct imbricating scales. It is therefore not improbable that perfect specimens would show other characters that would warrant the establishment of a new genus or subgenus for such forms, in which case the name Alepidaster might be applied to the group.”
Genoholotype.—Protaster (?) granuliferus Meek.
Original description of Protasterina.—‘‘ Rays five, slender, flexible, and ex- tending much beyond a cir- cular and minutely granu- lar disk, which is provided with short, slender, and outwardly directed spines; inner ray pieces [ambu- lacrajregularly alternating, of an hour-glass shape, and interlocking along the me- dian line, which is there- fore not straight but zig-
ZZ ; outer ray pieces elon- Fia. 26.—DIAGRAMS OF ALEPIDASTER GRANULIFERUS (MEEK). gated fadambulacrals or DRAWN BY E. O. ULRICH FROM A SPECIMEN IN THE UNITED
: : States NATIONAL MusSEUM. A, ACTINAL VIEW OF RAY side plates], directed ob- PLATES. B, SAME FROM ABACTINAL SIDE. C, SECTION
liquely outwards, so as to ‘THRovGH Ray. D, SIDE-PLATE FROM THE INSIDE AND IN partly overlap each other; “"°™ two rows of large pores between the inner [ambulacral] and outer [side plates] ray pieces; in the type-species these pores appear to have been occupied by loosely-fitting subpyramidal plates, some of which have a deep depression in the top, as though they were perforated; their true nature, however, is very uncertain. Oral pieces ten, each pair being formed by two of the outer ray pieces. Type, P. fimbriata.” When the original material of Alepidaster and Protasterina is re- studied, it may be shown that the latter is not a synonym of the former, but at present the writer does not see any generic differences. Alepidaster is easily distinguished from Protaster, not only by its ereater geologic age, but also in that its disk is minutely granular and spiniferous while that of the latter is scale-bearing. Further, when the exact shape of the ambulacrals is determined, it is probable that other differences will be found there. Particular attention should be paid to Ulrich’s statement that in Pretasterina the podial openings “‘appear to have been occupied by loosely fitting, sub-
230 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
pyramidal plates.” If these extra plates existed, Protasterina will be a good genus, differmg not only from Protaster, but also from Alepidaster.
Apparently no one has actually seen the abactinal side of the rays. The writer also fails to see it in the few specimens studied. It would, therefore, seem that there are no dorsal plates and that the dorsal covering is integumentary or finely granular.
This genus contains the following species:
A. (%), new species. Trenton.
A. granuliferus (Meek). Richmondian.
A. flecuosus (Miller and Dyer). Eden and Maysville. A. miamiensis (Miller). Richmondian (Waynesville).
ALEPIDASTER (?), new species.
In the Walcott collection at Harvard University there are three specimens (Nos. 28, 29, 30) of a “‘Protaster”’ that probably will prove to be new. They are from the Trenton limestone at Trenton Falls, New York.
ALEPIDASTER GRANULIFERUS (Meek). Text fig. 26.
Protaster ? granuliferus (Alepidaster at end of description) Mrrx, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 274; Geol. Surv. Ohio, Pal., vol. 1, 1873, p. 68, pl. 3 bis, figs. 8a, 8b.—J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 138.—Parxs, Trans. Canadian Inst., vol. 8, 1908, p. 368.
Original description.—‘‘ Disk small, apparently circular; rays rather slender, and of unknown length. Dorsal surface of disk and rays covered by an integument composed of innumerable minute grains of calcareous matter. Ventral side of disk not well exposed in the specimen but apparently provided, in the interradial spaces, with minute spines directed outward. Oral pieces not well exposed in the specimen. Arm pieces [ambulacrals] regularly alternating, but apparently rectangular at their inner ends, and not interlocking along the minute mesial impressed line, longer transversely than in the direction of the length of the rays; each largely excavated at its anterior outer end so as to form a large pore, or porelike depression, and divided transversely by a furrow into two parts, the anterior of which is very short, and the posterior longer, and marked by a minute [muscle] pit at its inner end; about eight or nine of these pieces in each range of each ray included within the margin of the disk. Outer arm [or ray] pieces (adambulacral of some) smaller than those of the the inner ranges, and placed edge upward, with an oblique outward direction so as to imbricate outward or toward the extremities of the rays, each bearing one or more minute articulating spines.
‘Breadth of disk, about 0.43 inch; breadth of arms at their inner ends, 0.10 inch.”
REVISION OF PALEOZOIC STELLEROIDEA. 931
Formation and locality.—In the lower part of the Richmondian at Moore’s Hill, Indiana. It was found by C. B. Dyer, and is now in the Museum of Comparative Zodlogy, Harvard University (No. 21).
ALEPIDASTER FLEXUOSUS (Miller and Dyer).
Plate 36, fig. 4.
Protaster flecuosus Miter and Dyer, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 31, pl. 2, figs. 1, la—Miter, N. Amer. Geol. Pal., 1889, p. 276, fig. 409.—Parks, Trans. Canadian Inst., vol. 8, 1908, p. 368.
Protasterina (‘‘ Protaster” lapsus) jimbriata Utricu, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 95, pl. 4, figs. 9-9c.
Protasterina flecuosa and P. fimbriata J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, pp. 139, 140. -
Original description of P. flecuosus.— The disk is composed of very thin, small plates, the order of arrangement of which is not deter- mined. The specimens examined differ in size, and show the disk varying in diameter from one-quarter to one-half an inch. The rays were very flexuous when living, and are found winding and turning and thrown in different directions in different specimens.
“Four series of plates are seen upon the dorsal side of each ray near the disk. The two inner series [the ambulacrals seen from the dorsal side] form an angular ridge, each plate is concave at the uniting surface, the arrangement is alternate, and the appearance, therefore, of the top of the ray, is something like the alternate arrangement of two series of hourglasses. ‘The outer series, or marginal [side] plates, are spinous, the spines directed toward the point of the ray. A weathered ray shows three series of pores—one row between the inner series of plates, and one between the marginal plates and inner series, upon each side of the ray [probably the plates are worn through by weathering; there should be but two rows of podial openings, the others being either muscle pits or weathering holes]. The plates are a little the longest in the direction of the length of the ray, and in this direction there are about four to the line. The rays cross the disk on the dorsal side and unite near the center of it, but the speci- men figured, Plate II, figure 1, has this part of the rays removed. Plate II, figure 1a, illustrates the ventral side of a specimen, which is too indistinct to show the arrangement of the plates. Small pieces, showing the ventral side of the rays, from other specimens, have two rows of spines springing from the marginal plates on each side of the rays.”
Original description of P. fimbriata.'.—*‘ Disk of medium size, circu- lar. Dorsal side of disk, and rays to margin of disk, covered with a granular integument. Ventral surface of disk provided with a large number of outwardly directed, short and slender spines. Oral
1 Ulrich still maintains that this species is a good one and distinct from P. flerwosus.
232 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
pieces 10, subrhomboidal in outline, arranged in pairs, each pair being formed of two of the marginal series of ray plates; on the lower inner edge there are five spines, and extending from each pair, over the mouth, is a bundle of rather long ones.
“Rays apparently very flexible, contracted toward the mouth; six series of plates are exposed on the ventral side of each ray. The two middle series [ambulacrals] alternate regularly, and interlock along the mesial line; they are about twice as long in the direction of the ray, than measuring transversely; each piece is contracted in the middle on the inner side to admit the wide ends of the two pieces immediately opposite, and on the outer side to form a pore- like impression, between them and the outer series of plates; four [five or possibly six] of these plates in each range of each ray are included within the disk, and the series terminate abruptly at a distance of one and a half lines from the inner end of the oral plates; from the margin of the disk to the extremity of the ray there are about 16 pieces in each range. The pores mentioned above, are occupied by a series of loosely fitting, obtusely conical or pyramidal plates, some of which distinctly show a deep depression in the top, and may have been perforated. Outer or marginal pieces [side plates] flat, placed on edge, and directed obliquely outward so as to overlap each other; the two free edges, that is, the one toward the point of the rays and the one seen on the ventral surface, are lined with from 10 to 12 short club-shaped spines, varying somewhat in length. The marginal [side plates] and middle [ambulacral] series of plates articulate by means of corresponding prolongations from the sides of the plates. These prolongations arise from near that end of the plate which is directed toward the mouth.
‘Dorsal side of rays composed of two rows of alternating and interlocking piates, which near the disk are very deeply sculptured and about as wide as long, becoming gradually less excavated, and longer in proportion to the width, toward the point of the rays; on each side they articulate with the upper edge of the oblique mar- ginal series of plates [these are the ambulacral plates seen from the dorsal side, either because there were no dorsal plates or because there was an integument].
“Breadth of disk, 0.60 inch; breadth of arm at margin of disk, 0.16 inch; length of same from oral plates, 0.88 inch. This species is related to Protaster flecuosus.”’
Formation and locality — This species has been found at differ- ent elevations from near low-water mark in the Ohio River [that is, in basal Eden] to the top of the hills at Cincinnati,” in the upper Maysville beds. The type-specimens of P. flenwosus were found by Mr. C. B. Dyer and are now in the collection of Harvard Uni- versity (Nos. 17, 18). Those of P. jfimbriata were obtained by
REVISION OF PALEOZOIC STELLEROIDEA, 23e
Ulrich in the lower Eden at about 100 feet above low-water mark in the Ohio River at Covington, Kentucky. This material is now in the Ulrich collection of the United States National Museum. Other poor specimens from a still lower level in the Eden and asso- ciated with Triarthrus are from the first ward, eastern Cincinnati. Two specimens are at Yale University.
Cat. No. 60615, U.S.N.M.
ALEPIDASTER MIAMIENSIS (Miller).
Protaster miamiensis MILLER, Journ. Cincinnati Soc. Nat. Hist., vol. 5, 1882, p. 116, pl. 5, figs. 6-6b.—J. F. James, Journ. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 138.—Parxs, Trans. Canadian Inst., vol. 8, 1908, p. 368.
Original description.—‘This species is large, with a proportion- ally small disk. A specimen having a disk four-tenths of an inch in diameter, has rays an inch in length. Five specimens have been examined, all showing the ventral side. The dorsal side is unknown. Only that part of the disk between the rays is visible in any of the specimens, and the plates are so anchylosed together that no special definition of them can be given. The rays are long and coarser and stronger than usual in this genus, though they were quite as pliable and flexuous when living as others. Two series of subquadrangular plates, or ambulacral ossicles, alternating with each other, constitute the bottom of each ambulacral furrow; these are bordered by spinous adambulacral plates, which terminate at the angles of the mouth in only five oral plates.”’
Formation and locality—In the Richmond formation, about Waynesville, Ohio. The specimens are in the Harris collection of the United States National Museum.
Cat. No. 40886, U.S.N.M.
Genus GREGORIURA Chapman.
Gregoriura CHAPMAN, Proc. Royal Soc. Victoria, n. ser., vol. 19, 1907, p. 24, pl.6, fig. 1; pl. 8, figs. 1, 3—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wies- baden, vol. 63, 1910, p. 238.
Original definition— ‘A Protasterid in which the usual boot- shaped ambulacrals are laterally developed, and modified into a subtriangular form. Ossicles on each side of the ambulacral canal subalternate, excepting at the junction with the mouth frames, where they are parallel. Adambulacral ossicles narrow, slender, extending laterally in a line with the proximal border of the ambu- lacral ossicle. Spine-bearing plates, slender, at right angles to the adambulacrals, carrying (in the genotype) two conspicuous spines. Oral skeleton having jaw plates three-fourths the length of the mouth frames; teeth thick and prominent. No traces of a disk preserved in the specimen on which the genus is founded. Arms very slender and very flexible.”’
234 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genoholotype and only species.—G@. spryi Chapman (same references
as above). _ Found in the Silurie (Melbournian) shale at South Yarra, Vic- toria, Australia. Genus BUNDENBACHIA Sturtz. Text fig. 27. Bundenbachia Stiirrz, Paleontographica, vol. 32, 1886, p. 83; vol. 36, 1890, p. 216.—Greeory, Proc. Zool. Soc. London for 1896, 1897, p. 1038, fig. 4 on p. 1034.—Parxs, Trans. Canadian Inst., vol. 8, 1908, p. 367.—ScH6n- porF, Paleontographica, vol. 57, 1910, p. 57.
Rays five, short, basally wide, terminally pointed or blunt. Disk large, soft and delicate, with concave interradial margins.
Abactinally the disk is covered with symmetrical scales, and medially there is a pentamerous rosette (the oral armature squeezed through), from the points of which the rays originate. Rays covered
with a granular integument. J Gregory states: “Ambulacral ossicles with ys RY a dumbbell-shaped body and thin tapering ae wing. The body of the ossicle is apparently divided into two pieces by a transverse de- Me ey pression. The adambulacral plates are small HRY ies and narrow, and support a triangular spine- We ge aks Res a hie, bearing plate. [There is only one plate here, rurr or BuNDENBacHIA. En- the adambulacral. There are no lateral
LARGED. AFTER GREGORY. pieces as in Ophiuroidea. ]
“The syngnaths are curved, narrow bars.”
Genoholotype and only species.—B. benecker Stiirtz.
Remarks.—“ Bundenbachia differs from Protaster by the irregular nature and soft plating of the disk, by the presence of spine-bearing plates attached to the adambulacral ossicles, and by the different form of the ambulacral ossicles.”” (Gregory.)
BUNDENBACHIA BENECKEI Stiirtz.
Bundenbachia beneckei Sttrtz, Paleontographica, vol. 32, 1886, p. 83, pl.8, figs. 7, 7a; pl. 9, figs. 1, la —Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1034, figs. 4 Formation and locality—Occurs in the Lower Devonie roofing slates of Bundenbach, Germany.
Genus PALAHZOPHIOMYXA Sturtz.
Palzophiomyzxa Stiirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 202.
Palzxophiomyxide Stiirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 202.—Scubnvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Genoholotype and only species.—P. grandis (Stiirtz).
REVISION OF PALEOZOIC STELLEROIDEA. 235 PALZOPHIOMYXA GRANDIS (Stiirtz).
Bundenbachia grandis Stirtz, Paleeontographica, vol. 32, 1886, p. 84, pl. 9, figs. 2, 2a, 3, 3a. Palxophiomyxa grandis Stirtrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 196, 202. Formation and locality—tLower Devonic roofing slates of Bun- denbach, Germany.
Cat. No. 59388, U.S.N.M. Family PALAZAOPHIURID Gregory.
Palxophiuride GreGcory, Proc. Zool. Soc. London for 1896, 1897, p. 1034; Treat. Zool., vol. 3, Echinoderma, 1900, p. 274.—Scu6nporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 237.
“Lysophiure in which the [alternate] ambulacral ossicles consist of a bar-shaped or subquadrate ‘body’ without wings.” (Gregory, 1900.)
Remarks.—This family differs from the Protasteride in “having the ambulacral ossicles longer than wide, and never divided trans- versely by muscular depressions. The ambulacral ossicles are either bar-shaped or thickened to a subquadrate form. They are never boot-shaped.”’ (Gregory, 1897.)
Schéndorf states that Gregory established the families Protas- teride and Paleophiuride on the form of the ambulacralia. He says: “The first family has boot-shaped, and the second family bar-shaped or subquadrate ambulacrals. The form of the latter is nothing more than a poor development of the boot-shaped type of ambulacrals. Accordingly the second family has no value and is to be withdrawn.” In addition the forms of Stiirtzura have boot- shaped ambulacrals, and these “are so little alternate in arrangement that their alternation appears to me more than questionable.” (Schéndorf, 1910.)
Contains the following genera:
Palxophiura Stiirtz. Stirtzura Gregory. FEugasterella, new name. Ptilonaster Hall.
Genus PALA OPHIURA Stiirtz.
Palxophiura Stirrz, Paleontographica, vol. 36, 1890, p. 233.—Greeory, Proc. Zool. Soc. London for 1896, 1897, p. 1034.
‘“Paleophiuride with the disk surrounded by rod-shaped marginal ossicles. The ambulacral ossicles are rods lying parallel to the arm.” (Gregory.)
Genoholotype and only species.—P. simplex Stiirtz (citations as above). Lower Devonic, Bundenbach, Germany.
236 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Genus STURTZURA Gregory.
Sturtzura GreGcorY, Proc. Zool. Soc. London for 1896, 1897, p. 1034.—ScH6n- porF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 215, 237.
?Rhodostoma Souuas and Souuas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 225 (genoholotype, Protaster leptosoma Salter.)
“Paleophiuride having thick, subquadrate, ambulacral ossicles and narrow adambulacral plates. The disk is fragile, and its plates are small and thin: it has no marginal plates. The mouth-frames are narrow and separate.
“ Distribution.—Silurian, England and Australia.”
Genoholotype.—Protaster brisingoides Gregory.
‘“Remarks.—This genus differs from Palzxophiura, as the ambu- lacral ossicles are thick and subquadrate, instead of being in the form of narrow bars; also by the absence of the strong marginal plates round the disk.” (Gregory.)
Chapman in 1907 refers the genotype back to Protaster, adding: “Tn consequence of this determination Sturtzura leptosoma may now be considered as the type of the genus.” This is in violation of the rules of nomenclature and the generic name will stand or fall on the basis of Protaster brisingoides.
Schéndorf states: ‘The ambulacra of S. brisingoides are not at all bar-shaped or subquadrate, if the figures of Chapman (1907, pl. 8, fig. 2) are correct, but are also essentially boot-shaped and alternate in arrangement. S. leptosoma also has alternating ambu- lacra. Their identity with Lapworthura miltoni ranges them with the Auluroidea, where S. brisingoides undoubtedly also belongs. That this form and with it also the genus Sturtzura is to be retained as valid is very questionable, but the final answer may as well wait until the originals are restudied. In any event it is plain that both forms can not belong to the Lysophiure.”’
Contains the following species:
S. brisingoides (Gregory). Siluric of Australia. S.leptosoma (Salter). Ludlow of England. S. leptosomoides Chapman. Siluric of Australia.
STURTZURA BRISINGOIDES (Gregory).
Teniaster australis McCoy, see CHAPMAN 1907, p. 23 (nomen nudum).
Protaster brisingoides GreGoRY, Geol. Mag., dec. 3, vol. 6, 1889, pp. 24-27, fig. 1.— CHAPMAN, Proc. Roy. Soc. Victoria, n. ser., vol. 19, 1907, p. 22, pl. 6,
fig. 2; pl. 8, fig. 2. Sturtzura brisingoides GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 1034. Formation and locality —From Siluric sandstones at Moonee Ponds Creek, Flemington, near Melbourne, Australia. The type-material is in the British Museum (Natural History), London. Other speci- mens from the same locality and from the parish of Yering, Upper Yarra district. Victoria, are in the National Museum at Melbourne.
REVISION OF PALEOZOIC STELLEROIDEA. 237
STURTZURA LEPTOSOMA (Salter).
Protaster leptosoma Sauter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 331, pl. 9, fig. 5.—Wrieut, Mon, British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palzontogr. Soc. for 1861), 1862, p. 33.—Quensrept, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 133, pl. 95, fig. 12.—Stiirrz, Paleeonto- graphica, vol. 32, 1886, p. 79; N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 148.
Sturtzura leptosoma GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 1035.— CHApMAN, Proc. Roy. Soc. Victoria, n. ser., vol. 19, 1907, p. 26, pl. 8, fig. 5.— Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 215.
Rhodostoma leptosoma Souruas and Souxas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 223, text fig. 4C, pl. 9, figs. 3, 4.
Formation and locality—Common in the Siluric, Ludlow forma- tion, at Leintwardine, Shropshire, England.
Remarks.—Schéndorf says S. leptosoma is but a miniature edition of Lapworthura miltoni, both forms being completely identical. The disk margin is not convex but concave between the radii.
STURTZURA LEPTOSOMOIDES Chapman.
Sturtzura leptosomoides CHAPMAN, Proc. Roy. Soc. Victoria, n. ser., vol. 19, 1907, p. 26, pl. 7, figs. 1, 2; pl. 8, fig. 4.
Formation and locality—In the Siluric (Melbournian), Moonee Ponds Creek, Flemington, near Melbourne, Australia.
Genus EUGASTERELLA, new name.
Eugaster. Haut (not Eugaster Seville 1839, Orthoptera), Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 290; rev. ed., 1868=1870, p. 332.—ZrrreL, Handb. Pal., vol. 1, 1879, p. 444.—Stiirrz, N. Jahrb. fiir. Min., etc., 1886, vol, 2, p. 151.—Mrmer, N. Amer. Geol, Pal., 1889, p. 244.—Sritirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 20.—Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1035.
Eugasterella Scuucuert, Fossilium Catalogus, Animalia, pt. 3, April, 1914, p. 19.
Original description. Body stellate, consisting of a central alated disk, and five long, slender, somewhat flexuous rays. Disk composed of small, polygonal tuberculose or subspinose plates on the ventral side. Rays consisting of a double series of alternating subquadrate ambulacral ossicles, and a series of curved adambulacral plates bordering the grooves, and forming the margin of the ray; the outer ends overlap the edge of the next plate in advance. Oral plates ten, arranged in pairs, forming the terminal plates of the adambulacral ranges. Pores large, arranged in two rows in each ray; penetrating the ray at the junction of the ambulacral and adambulacral plates in such a manner that four different plates border each perforation. Adambulacral and disk-plates bearing spines. Dorsal surface unknown.”
Genoholotype.—E. logani (Tall).
238 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Gregory comments on this genus as follows:
“Paleophiuride in which the ambulacral ossicles are subhep- tagonal in form, the central suture along the arm being zigzag, while the outer angles of the ossicles are cut away for the reception of the podia. The adambulacral ossicles have a flat base, and thence bend forward crescentically. The mouth frames are massive, and those of each pair meet along the middle line of the oral angle.
“This genus I only know from Prof. James Hall’s figures, and, in spite of their clearness, I feel much doubt as to the wisdom of diag- nosing it from these alone. Its affinities are clearly with the Pale- ophiuride, but it approaches the Protasteride in one respect, for, owing to the deep depressions in the outer angles of the ambulacral ossicles, the outer side forms a short rudimentary wing. The genus differs from all the Protasteride by the absence of a muscular groove across the ambulacral ossicles.
“Among the Paleophiuride it differs from Palexophiura by the absence of marginal ossicles, and from Sturizura and Teniura by the massive nature of the mouth frames.”
Contains :
E. logani (Hall). Hamilton. E. (2) concinna (Ringueberg). Rochester.
EUGASTERELLA LOGANI (Hall).
Eugaster logani Haut, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 290; rev. ed., 1868=1870, p. 333, pl. 9, figs. 7, 8.
Original description — Body stellate, with a small disk and long attenuate flexuose rays. Disk composed of numerous small poly- gonal plates with radiated surfaces; the diameter, measured from the sinus to its extension on the opposite ray, is about half as great as the length of the ray measured from the center of the disk. Rays, as seen from the ventral side, narrow, attenuate, with the ambulacral plates curving, and near the base of the rays a little wider than long, and toward the extremities longer than wide, with a strong elevated transverse ridge. There are about eight pairs of plates inclosed within the limits of the disk. Pores penetrating the interstices near the outer extremities of the plates, while near the inner end there is a depression or pit resembling a partially excavated pore. The adambulacral plates as seen from below are extremely narrow and very convex on their outer surfaces, forming the margins of the ray. Oral plates in pairs, narrow and elongate.
“This specimen measures, from the center of the disk to the extrem- ities of the rays, about one inch and a half; the widest part of the ray, which is near the margin of the disk, is about an eighth of an inch in diameter. The rays toward their extremities have the ambula- cral field covered by the curving of the marginal plates over the
REVISION OF PALEOZOIC STELLEROIDEA. 239
groove, and which, closely uniting by their margins, give a tereti- form termination of nearly one-third the entire length, each one having the aspect of a slender crinoidean proboscis.
“Geological formation and locality—In the Hamilton group, near Fenner, in Madison County, New York. The specimen was collected during the geological survey, and is now in the State Museum.”
EUGASTERELLA (?) CONCINNA (Ringueberg).
Eugaster concinnus RINGuEBERG, Bull. Buffalo Soc. Nat. Sci., vol. 5, 1886, p. 8, pl. 1, fig. 3.
This species does not belong to Eugasterella, but until the holo- type is restudied it can remain in this genus. It is from the Rochester shale at Lockport, New York, and is in Dr. Ringueberg’s collection.
Original deseription.—* Disk flat, thin, alated, composed of very fine granulose plates. Rays broad at their base; flattened, rapidly tapering for two-thirds of their length; terminal third attenuate, rounded; plates, if any, undefinable.
“Dorsal side with four series of plates; two median and two lateral; the transverse sutures dividing the outer series are continuous with every other transverse suture dividing the central series. Medial series with twice the number of plates of the outer, and are raised above them.
“Sutures depressed. Surface of the plates rounded and finely granular.
“The lateral series of plates decrease regularly in size after reach- ing the disk until they ond in a pronounced elevation formed by the last pair of the medial series at a point about halfway from the border toward the center of the disk—measuring at the narrowest part—where both series end. Between these elevations the disk has a shallow, stellate depression with the points opposite the several rays. The two outer rows of plates apparently disappear toward the attenuate tip before the median does so. The imperfect cast of the upper part of one of the rays is all that is known of the ventral side; this shows traces of an alternating series of ambulacral plates.
“Marginal plates spiniferous.
“Length of ray, one-half inch.”
Genus PTILONASTER Hall.
Ptilonaster Hati, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, pp. 291-292; rev. ed., 1868=1870, p. 334.—LttTKen, Dansk. Vid. Selsk. Skrift., ser. 5, vol. 8, pt. 3, 1869, p. 82.—Srirrz, Paleontographica, vol. 32, 1886, p. 83; N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 152.—Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1036.—Sriirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 188.
Palxocoma MiuuErR (part), N. Amer. Geol. Pal., 1889, p. 266. |
Original description.—‘ Form and general features as in Lugaster, but differing in the plates of the rays. Rays composed of an ambu- 50601°—Bull. 88—15——16
240 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
lacral, adambulacral and marginal series, which are united by their edges, and apparently not imbricating, the projecting or oblique anterior face of the marginal plates bearing spines which are inclined toward the extremity of the ray. Margins of the rays alated by the extension of the disk.
“T had originally united this form with Hugaster, but further ex- amination has shown the ray to have a range of marginal plates outside of the adambulacral plates, and I am unable to discover any such feature in Hugaster logani.
“This and the preceding genus [Hugasterella] belong to the Ophiu- ridx, to which may also be referred the genus Protaster.”’
‘¢ Note.—It is only as these pages are going to press that my atten- tion has been directed to the similarity of structure in the ray of Palzocoma of Salter with that of the proposed genus Ptilonaster. In this illustrated species of the former genus (Palzocoma marstont) the disk is proportionately larger, and the rays much shorter, while the outer range of plates is represented as imbricating; but being characterized by a double row of plates bordering the ambulacral area, it must be regarded as very nearly related if not generically identical with Ptilonaster.”
Gregory comments on Ptilonaster as follows: ‘‘This genus is an ally of Eugaster; * * * it is, however, generically distinct. I only know it from Hall’s figures, and therefore prefer to leave the prep- aration of a formal diagnosis to an American paleontologist.”
Genoholotype and only species.—P. princeps Hall.
PTILONASTER PRINCEPS Hall.
Ptilonaster princeps Hatt, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 292; rev. ed., 18681870, p. 334, pl. 9, fig. 9. Palzxocoma princeps MiutER, N. Amer. Geol. Pal., 1889, p. 267.
Original description —‘‘The specimen consists of the impression of the greater part of one ray, with parts of two others, and intervening portions of the disk. The disk has extended along the ray nearly an inch from the center of the body; the plates are small, and have been furnished with slender spinules. The ray is strong and extremely elongate, having been at least 44 inches in length; its greatest width is outside of the disk, where it measures seven-sixteenths of an inch. The ventral side of the ray shows three series of plates—ambulacral, adambulacral, and marginal—on each side of the center; of these at least seven ranges have been included within the disk. The ambula- cral plates are a little wider than long, arranged in alternating order. The pores penetrate the interstices near the outer extremity of the plates, while the partial or obsolete pores are obscure, becoming deeper and more conspicuous toward the extremity of the ray. Near the base of the ray there are 12 plates in the length of an inch,
REVISION OF PALEOZOIC STELLEROIDEA. 941
and 14 plates in the same distance in the central portion, while toward the extremities there are 20 or more in the same space. The marginal plates are subhexagonal, a little longer than wide, and ornamented by long slender spines on their outer margins.
“This is a much larger and more robust species than the Lugaster logani, and in its entire condition it is the largest star-fish known in our palzozoic rocks.
“Geological formation and locality—In the Chemung group. The specimen is in a brownish-gray sandstone, which weathers to a very light ashen color. It was received from Henry S. Randall, Esq., of Cortlandville [New York], in the vicinity of which place it was ob- tained.”’
The holotype, an imprint, is in the American Museum of Natural History, No. 4472.
Family ENCRINASTERIDA, new name.
Aspidosomatide GreGorRY, Geol. Mag., dec. 4, vol. 6, 1899, p. 351; Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.—Scuénporr, Palontographica, vol. 57, 1910, pp. 55-61.
Palzgoniasteride Stirrz (part), Paleeontographica, vol. 36, 1890, p. 246 (contains Aspidosomella and Palzaster).
Lysophiure with boot-shaped ambulacralia ventrally, and large disks that are bordered with simple marginalia. Apparently only the inframarginals are present.
As Aspidosoma Goldfuss is preoccupied, this name can no longer be used for the family name. Hncrinaster Haeckel replaces it and therefore becomes the base of the family designation.
The family has the single genus Encrinaster.
Genus ENCRINASTER Haeckel. Plate 35, text fig. 28, 29.
Aspidosoma Goupruss (not Aspidosoma Fitzinger 1843, Reptilia), Verh. naturh. Ver. preuss. Rheinl., etc., vol. 5, 1848, pp. 145-146.—Smonovirtscu, Sitzb. d. mat.-naturw. Classe Akad. Wiss., Wien., vol. 64, Abt. 1, 1871, p. 103.— ZirreL, Handb. Pal., vol. 1, 1879, p. 451, fig. 322.—Sriirrz, Paleeonto- graphica, vol. 32, 1886, p. 92; N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 151; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 38, 55.—ScH6n- porr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 35; Palzontographica, vol. 57, 1910, pp. 1-63.—SpEencEr, Mon. Brit. Pal. Aste- rozoa, pt. 1 (Palzontogr. Soc. for 1913), 1914, pp. 23, 24, 49.
Encrinaster HArcxet, Gen. Morphologie, vol. 2, 1866, p. xvii (genolectotype Aspidosoma arnoldi Goldfuss).
/Nagnosis.—Animals attaining large size, with a comparatively large disk. ays five, more or less petaloid, slender and long, with wide and open ambulacral furrows.
242 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
‘“Ambulacrals alternating in adjoining columns, while the neigh- boring ambulacrals and adambulacrals are directly opposite each other. The margin of the disk is concave and limited by a row of more or less conspicuous simple [not two rows of superposed] marginalia restricted to the disk. The sides of the free rays are bounded by adambulacrals. These and the ambulacrals are [common to the two sides of the animals, and abactinally are] roughly sculp-
tured, usually naked, and only
(as iby [r, | 4) in rare cases were adambulacral ie spines observed. Madreporite [7] o.2} actinal, situated near the peri-
stome in one of the interradial
i ee ; areas nearest to the left adam-
Fig. 28.—AMBULACRALIA AND ApAMBuLAcRALIA or Dulacrals of a radius.” (Sch6n- ENCRINASTER ROEMERI, AFTER SCHONDORF. 4, AP- PEARANCE OF THE PLATES WHEN CRUSHED OR OB- dorf, 1910 ) 3 SCURED BY CLAY. EACH AMBULACRAL HERE APPEARS Genolectotype.—Aspidosoma ar-
ss ov 2wo Tots). a DETER PRISER? mold Goldfuss. Genus restricted
CLES WHEN WELL PRESERVED AND compterety to the Lower Devonic of Rhenish
CLEANED OF CLAY. Germany.
Remarks.—This well-known genus has been referred to the asterids and to the ophiurids, and though it has most often been placed among the true starfishes, it now appears to belong to neither of these orders. Schéndorf has restudied the material with great care and has made out the detail of the ambulacralia, with the result that he erects for Aspidosoma the order Auluroidea. In the work of 1910 cited above the matter is set forth in great detail, and all that can be done here is to direct atten- las tion to the more important of his illustrations, with their descriptions, reproduced in part here and on pages 213 and 214.
As Aspidosoma was first used for a genus of reptiles, it can not, under the rules of nomen- {| clature, be used again for another group of \ animals. It is possible, however, under the Fic. 29—Orar skELEToN oF rules to make use of Hncrinaster, but in doing eee eee econ sibe so the proceeding should first be explained. MUCH ENLARGED. AFTER
Encrinaster was proposed by Haeckel as fol- ““°%?°™* lows: In defining his sixth order of asterids, the Crinastra or lily stars, forms that he said already had crinoid characters, he cited as exam- ples of it Protaster sedgwickii and P.= Aspidosoma arnoldi. These forms, he added, are so different from Protaster miltont ‘‘that we here separate the former as Encrinaster (FE. sedgwickii, E. arnoldi, ete.).” Under ordinary circumstances it would be best to disregard the name because of the inadequate definition, but as Aspidosoma is preoccupied, we are obliged to propose another name to take its
REVISION OF PALEOZOIC STELLEROIDEA. 243
place. The first mentioned genotype of Lncrinaster is Protaster sedqwickii, but as this is also the type-species of Protaster, a genus in good standing, we may accept the second named species, Aspido- - soma arnoldi. ‘Therefore it is here proposed to replace Aspidosoma Goldfuss (not Fitzinger) by Encrinaster Haeckel, with Aspidosoma arnoldi Goldfuss as the genolectotype.
ENCRINASTER ARNOLDI (Goldfuss).
Aspidosoma arnoldi Gotpruss, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 5, 1848, pp. 145-146, pl. 5.—Muuier, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 12, 1855, p. 4, pl. 1, figs. 1-3.—Srirrz, Paleontographica, vol. 32, 1886, p. 93.—ScHONDoRF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 38; Paleeontographica, vol. 57, 1910, pp. 4, 62, pl. 1, fig. 2; pl. 2, figs. 6, 7; pl. 3, figs. 7-9; Jahrb. preuss. geol. Landesanst., Berlin, vol. 29, 1908, p. 706.—Sprencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontoer. Soc. for 1913), 1914, p. 40.
Encrinaster arnoldi Harcket, Gen. Morphologie, vol. 2, 1866, p. lxvii.
Formation and locality.—This species is common in the grauwacke of the Lower Coblenzian at Winningen, on the Mosel, Germany.
ENCRINASTER GOLDFUSSI (Schéndorf). Text fig. 29.
Aspidosoma goldfussi ScHONDORF, Paleontographica, vol. 57, 1910, pp. 11, 62, pl. 3, figs. 1, 6. Formation and locality —A common form found associated with E. arnoldi about Winningen, Germany.
ENCRINASTER PETALOIDES (Simonovitsch). Plate 35, figs. 5, 6.
Aspidosoma petaloides Stuonovitscu, Sitzb. mat.-naturw. Classe Akad. Wiss., Wien., vol. 64, Abt. 1, 1871, p. 106, pl. 4, figs. 1-3.—Zrrret, Handb. Pal., vol. 1, 1879, p. 453, text fig. 322.—Sriirrz, Paleeontographica, vol. 32, 1886, p. 92.—Scu6bnvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, p. 37, pl. 4, figs. 4, 5; Paleeontographica, vol. 57, 1910, pp. 14, 63, pl. 1, figs. 3, 4; pl. 2, fig. 4; pl. 3, figs. 10-16 (complete synonymy given here). This species is described in great detail by its author and by Schoéndorf, and is well ulustrated. Here as elsewhere the abactinal skeleton is that of the actinal area seen from the dorsal side. Four specimens of this species were found in grauwacke of Upper Coblenzian age, in the old quarry back of the Hohenrheiner furnace at Niederlahnstein, Rhenish Germany.
ENCRINASTER PETALOIDES GOSLARIENSIS (Halfar).
Aspidosoma petaloides, var. goslariensis Hatrar, Jahrb. preuss. geol. Lande- sanst., Berlin, vol. 18, 1893, p. 186, pl. 10, figs. 1, la.—Scuénporr, Paleeontographica, vol. 57, 1910, pp. 21, 63, pl. 2, fig. 5; Jahrb. preuss. geol. Landesanst., Berlin, vol. 29, 1908, p. 707.
Formation and locality —The holotype is from the Lower Devonic of the Harz, Germany.
244 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
ENCRINASTER TISCHBEINIANUS (Roemer) emend. Stiirtz.
Aspidosoma tischbeinianum RoEMER, Paleeontographica, vol. 9, 1863, pp. 144-146, pl. 23.—QueEnsrep?, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 76, pl. 92, fig. 39.—Sriirrz, Paleontographica, vol. 32, 1886, p. 92, pl. 12, figs. 1, 2.—Scubnporr, Paleontographica, vol. 57, 1910, pp. 23, 62, pl. 1, fig. 1; pl. 3, figs. 4, 5 (complete synonymy given here).
Formation and locality—Common in the roofing slates of the Rhenish Lower Devonic at Bundenbach, near Birkenfeld, Germany. As many as 60 individuals have been found on a slab.
Cat. No. 35117, U.S.N.M.
ENCRINASTER ROEMERI (Schéndorf). Text fig. 28.
Aspidosoma tischbeinianum RoEMER (part), Paleeontographica, vol. 9, 1863, pl. 25, fig. 11.
Aspidosoma roemeri ScHéNvDoRF, Paleontographica, vol. 57, 1910, pp. 28, 62, pl. 2, fig. 3; pl. 3, figs. 2, 3.
Formation and locality —Found associated with FE. tischbeinianus at Bundenbach, Germany.
ENCRINASTER SCHMIDTI (Schéndorf).
Aspidosoma schmidti ScuHénvorr, Paleeontographica, vol. 57, 1910, pp. 31, 63, pl. 1, fig. 6; pl. 3, figs. 17, 18 (complete synonymy given here).
Formation and locality —A slab with six specimens from the Lower Devonic (Herdorfer zone of the Siegen) at Oberdielfen, Germany.
ENCRINASTER EIFELENSIS (Schéndorf).
Aspidosoma eifelense ScHdNDoRF, Paleeontographica, vol. 57, 1910, pp. 34, 63, pl. 1, fig. 5.
Formation and locality —Known by several examples from the Lower Coblenzian at Oberstadtfeld, Eifel, Germany.
ENCRINASTER PONTIS (Clarke).
Aspidosoma ? pontis CtaARKE, Monog., I, Serv. Geol. Min. Brasil, 1913, p. 312, pl. 27, figs. 1-8; Bull. N. Y. State Mus., No. 164, 1913, pl. 35, figs. 1-4.
Original description. —‘‘This very graceful starfish occurs in abund- ance in the soft gray shales of Ponta Grossa, sometimes in clustered groups with its long and slender arms curled and intertwimed, more often as single individuals lying in beds with shells of Orbiculoidea and various lamellibranchs. I have counted 20 individuals among the specimens at my command and, singularly, every one of these is preserved with its ambulacral face up. The removal of all calcareous matter has left only internal casts of this surface from which it has been possible to gain an idea of external structures from carefully
REVISION OF PALEOZOIC STELLEROIDEA. 245
made impressions. No specimen gives any clue to the dorsal exterior save one arm which has been turned sidewise showing a part of that surface.
‘‘The striking character of this starfish is the unusual delicacy of its arms, which are very slender and long for a true asteroid and present an appearance very suggestive of an ophiuran. These slender arms are usually so exposed as to show only the alternating am- bulacral plates which increases the effect of slenderness; but the adambulacrals are occasionally present and give the arms increased width. These arms are all clearly sulcate, the median groove being sharply marked in all casts by a thin elevated ridge running the entire length of the arm. The soft shale holding these specimens is not a very satisfactory matrix from which to take the special struc- tures of the animal but in good part these can be made out. The ambulacral plates are quadrate in outline, alternate in position along the arm groove, and together are arched so that normally the am- bulacral surface is an arched ridge rising above the rest of the surface. These plates, in their arched position, are slightly spaced or dis- placed along adjoining edges leaving passages from the ambulacra. They are usually broken down or slipped over each other in com- pression so that the arm seldom shows them in the true position. The surface of these plates is finely granular. The adambulacrals constitute one (or more?) lateral rows and are so seldom well defined that I am not able to represent them with precision but each of them seems to carry one short spine and all to be granulated on the surface. The body of the animal is deeply incut by the arms, which radiate from a narrow center, sharply quinquepartite by the buccal cavity. The oral apparatus is pretty well made out. The oral frames, one for each arm, are very conspicuous, though varying in size in different individuals. Each is broadly saddle-shaped, split medially, the distal parts joined by a suture, the proximal ends spreading apart at a sharp angle which opens into the oral cavity. Their surface is rounded and granulate, the distal ends elevated, and often each half is inclined downward toward the other along the median suture. At each proximal angle lies a sharp jaw or tooth. _The whole of the body surface is occupied by the oral rosette composed of the five buccal divisions.”
Formation and locality—¥rom the Devonic of Ponta Grossa and Jaguariahyva, Brazil.
ENCRINASTER (?) GRAY (Spencer).
Aspidosoma grayx SPENCER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pp. 23, 24, 33, 38, text figs. 22, 24, pl. 1, fig. 8.
Occurs in the Caradoc of Great Britain.
246 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Order STREPYOPHIURAS Bell.
Streptophiure Bett, Proc. Zool. Soc. London for 1891, 1892, p. 179.—Grreory, Proc. Zool. Soc. London for 1896, 1897, p. 1036; Treat. Zool., vol. 3, Echino- derma, 1900, p. 274.
Protophiureex Sviirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 200.—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 234, 239, 251.
Ophiurasterix ScubnvorrF, Paleeontographica, vol. 57, 1910, p. 61.
. Diagnosis by Gregory (1897).—Auluroidea “in which the ambu- lacral ossicles are opposite and are generally fused into vertebral ossicles. In such cases the vertebral ossicles articulate by a more or less simple ball-and-socket joint.”
“ Remarks.—The main character of this order is that the ambu- lacral ossicles are paired, but primitive. The order differs from the preceding [Lysophiure] by having the vertebral ossicles always opposite instead of alternate. In some of the simplest members of the order, as Ophiurina, the ossicles are not fused, there are no ventral arm shields, and an ambulacral furrow runs along the ven- tral side of the arm. In the next higher family, as in the genus Lapworthura, the ambulacral ossicles are fused, but have plain articulating surfaces, and there is an ambulacral furrow.”
Contains the families:
Ophiurinide. Lapworthuride. Eoluidiide. Aganasteride. Cholasteride.
Family OPHIURINIDA Gregory.
Ophiurinide Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1037; Treat. Zool., vol. 3, Echinoderma, 1900, p. 275.—Srtrtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 201.—Scu6nvorr, Jahrb. nassauisch. Ver.
' Naturk., Wiesbaden, vol. 63, 1910, p. 234. Original diagnosis —‘Streptophiure with ambulacral ossicles, only slightly united, and without ventral arm plates.” Contains the genera: Ophiurina Stiirtz. Tremataster Worthen and Miller.
Genus OPHIURINA Sttirtz.
Ophiurina Sriirrz, Paleontographica, vol. 36, 1890, p. 232.—Grecory, Proc. Zool. Soe. London for 1896, 1897, p. 1037.
Gregory’s diagnosis reads as follows: ‘‘Disk circular, with mar- ginal plates. Ambulacral ossicles long, narrow bars. Syngnaths
rod-shaped. Adambulacral plates absent or altogether lost from the fossil.”
REVISION OF PALEOZOIC STELLEROIDEA. 247
Genoholotype and only species —O. lymani Stiirtz (citations as above). Lower Devonic, Bundenbach, Germany.
Genus TREMATASTER Worthen and Miller.
Tremataster WorTHEN and Miter, Geol. Surv. Illinois, vol. 7, 1883, p. 330.— Mitter, N. Amer. Geol. Pal., 1889, p. 286.—Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1037.
Original description‘ Body stellate, central part discoid, rays long, flexuous, and gradually tapering. Rays consisting of a double series of ambulacral plates, forming, together, a subcuneiform se- ries, with the tapering ends dinoeted toward ite apices of the rays and uniting with the larger ends of the succeeding double plates, upon each side of which there is a series of curved adambulacral plates, which form the margins of the rays. The pores are large and situated between the contracting sides of the ambulacral ne and the concave sides of the curving adambulacrals. Four plates border upon each pore though menue surrounded by two of them. Plates 10. Dorsal surface unknown.
“This genus is distinguished by the parallel arrangement of the ambulacrals and adambulacrals, instead of the alternate order, and by the large pores.”
Gregory’s diagnosis is as follows: ‘Disk with concave inter- brachial outlines. No marginal plates. Ambulacral ossicles short. Adambulacrals present.”’
Genoholotype.—T. difficilis Worthen and Miller. T. (?) decheni (Dewalque) may also belong here.
TREMATASTER DIFFICILIS Worthen and Miller.
Tremataster diffcilis WortHeN and Mitier, Geol. Surv. Illinois, vol. 7, 1883, p. 330, pl. 31, figs. 3a, 3b.
Original description — Body stellate, disk small, rays long, flexuous, and gradually tapering. Ambulacral plates subtrigonal, elongated, and united upon their straight faces in parallel order, so as to form a series of subcuneiform sections at the bottom of the ambulacral groove, with the tapering end of each directed toward the apex of the ray, and uniting with the larger end of the next succeeding double plate.
“Adambulacral plates parallel with the ambulacrals, and each forms a curve from the larger end of an ambulacral toward the apex of the ray, to unite with the next succeeding adambulacral as it curves away from its attachment to the ambulacral. By this order of construction the adambulacrals are fixed, at one end, to the ambulacrals, while the other end moves upon the curved surface of an adambulacral so as to allow the same lateral flexibility of the rays, secured in other genera by the alternate arrangement of
248 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
the plates. The pores are large and situated between the contract- ing sides of the ambulacral plates, the concave sides of the adam- bulacrals, and the attaching ends of the succeeding plates, so that they are bounded by four plates while nearly surrounded by two. “The oral plates form, in pairs, elongated triangles, with the acute angle directed toward the center of the visceral cavity. The apices are joined by a suture with the basal portions, which are partly separated by a dividing furrow. A single genital pore per- forates each basal section of the oral plates. Dorsal side unknown. ‘Locality and position: Prairie du Long Creek, Monroe County [Illinois], Chester limestone. “No. 2479, Illinois State collection of 1878.” TREMATASTER (?) DECHENI (Dewalque). Protaster decheni DewaLque, Ann. Soc. géol. Belgique, vol. 8, 1880, pp. 52-54, pl. 3p aigs. dy2. Tremataster (?) decheni Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1037, footnote. Formation and locality—Upper Devonic at Walcourt (Namur) and Tohogne (Luxemburg), Belgium.
Family LAPWORTHURID Gregory.
Lapworthuride Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1037.— Srirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 203.— Grecory, Treat. Zool., vol. 3, Echinoderma, 1900, p. 275.—ScHONDoRF, Palseontographica, vol. 57, 1910, p. 58; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, pp. 235, 239.
Furcasteride Svirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 203.—ScuHonporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910,
. 230.
Pineiae pees Srirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 201.—Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Original diagnosis. —‘‘Streptophiuroida without ventral armplates or buccal shields; ambulacral ossicles fused, but their articulating surfaces are plain. Madreporite dorsal.” Schondorf states that this plate is on the ventral side, and that the ambulacrals are not fused (p. 239).
Contains the genera:
Squamaster Ringueberg. Lapworthura Gregory. Stirtzaster Etheridge. Bdellacoma Salter. Rhopalocoma Salter. Hallaster Stiirtz. Sympterura Bather. Furcaster Stiirtz. Palastropecten Stirtz.
REVISION OF PALEOZOIC STELLEROIDEA. 949
Stiirtz proposes that the family Lapworthuride be divided into three families. In the original family will remain Squamaster, Lap- worthura, Hallaster, and Sympterura. The family Furcasteride has Furcaster, while the Paleospondylide embraces Palzospondylus, the latter name being later changed to Palastropecten by Sttirtz, as it was preoccupied; the family name will, therefore, have to be changed to Palastropectinide, as was done by Bather in 1905 (p. 168).
Genus SQUAMASTER Ringueberg.
Squamaster RINGUEBERG, Bull. Buffalo Soc. Nat. Sci., vol. 5, 1886, p. 5.
Original description —‘‘Body small. Rays long, slender, tapering, flexible, and divided into annular segments.
‘‘Ventral side of ray with two series of paired, opposite ambulacral plates, divided by a straight median line; they are irregularly sub- quadrilateral, with one short side, and are arranged in pairs in each series, so that two long and two short sides are joined alternately; consequently there is a long transverse suture regularly alternating with a short one. This disposition gives dentate lateral margins to the ambulacral series. The lateral ends of the long transverse sutures curve away from each other, leaving a small notch between the inferior plates of each pair and the superior plates of the adjoming pairs. This notch receives the inner lateral corners of the squamose dorsal plates. Between the dentate elevations of the ambulacral plates and the lateral margins of the dorsal plates there are large triangular openings, which constituted, or in which were placed, the pores.
‘‘Dorsal side composed of large, quadrangular, squamose plates, that encircle the arm as far as the ambulacral groove of which they form the margin. They are divided in the upper portion of the ray by a median suture.
‘‘Dorsal, ray plates fimbriated on the free margins.
‘All plates are perforated by minute, closely arranged pores.”
Genoholotype and only species —S. echinatus Ringueberg.
SQUAMASTER ECHINATUS Ringueberg.
Squamaster echinatus RinavuEBERG, Bull. Buffalo Soc. Nat. Sci., vol. 5, 1886, pe 6) pl. w, fen:
Original description—‘ ‘Body small. Rays long, slender, not widen- ing at the base; regularly tapering to a subobtuse point. Dorsal side covered by thin imbricating plates, with free external margins which are edged on the outer and lateral sides with closely arranged, long, slender, filiform spinules, that articulate into minute rounded sockets, which are scalloped out of the margin of the plate; they are slightly longer than the exposed portion of the plate, and are placed about their own diameter apart.
250 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
“Ray divided into about 40 segments or articulations by the encircling, dorsal plates; these grow rapidly narrower near the body, and are divided by a dorsal suture running along a raised median ridge which extends about two-fifths of the length of the ray from the body out, where it gradually disappears with the last. divided plate; the rest are entire. These plates are quadrangular, and have their inner corners articulated into the socket formed in the dentate | lateral extensions of the ambulacral series. They are ornamented on each side by two or three closely arranged, subparallel, very fine ridges, that commence near the dorsal line at the free margins and extend diagonally backward across the plate toward the inner lateral articulated corner. Ambulacral groove furnished with opposite, irregularly quadrilateral, ambulacral plates, divided by a median ~ suture which is crossed alternately by one long and one short suture.
“The superior plate of each pair has the greatest extension later- ally, while in the inferior it is the direction of the median line, it being about twice as long as the superior, which, however, is but slightly broader.
‘‘Between the lateral margins of the dorsal plates and the dentate elevations of the ambulacral plates are large subtrigonal open spaces.
“The plates are punctured by very closely arranged minute perforations.”’
Formation and locality —In the Rochester shale, at Lockport, New York. The holotype is in the collection of Dr. Ringueberg. At least one (No. 1110) and probably two other specimens (No. 465) are in the Walker collection of the University of Toronto. They are from the Rochester shale, at Grimsby, Ontario.
Genus LAPWORTHURA Gregory. Text fig. 30.
Lapworthura Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1037, fig. 5.— ScuOnvorr, Paleeontographica, vol. 57, 1910, p. 58; Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 208.—Soxzas and
SS Sotuas, Philos. Trans. Roy. Soc. London, ser. B, vol. EE. 202, 1912, p. 213.—Spencer, Mon. Brit. Pal. Asterozoa, ale pt. 1 (Palzontogr. Soc. for 1913), 1914, pp. 25, 32, 40, 49. | Original diagnosis—‘‘ Disk circular, well SS marked. Arms very flexible, broad; at first rig, 30._Venrrar, sraucrone Uniform in width and then tapering slowly. or ARM oF Larworruura, Ambulacral ossicles with the distal and prox- AFTER GREGORY. : : : ° imal margins parallel; with lateral wings curv- ing round the podial pores. Madreporite large,’’ dorsal. Genoholotype.—Protaster miltoni Salter. Schéndorf remarks as follows (19100:58): The ossicles of Lapworthura have been described several times, but never correctly. The ambulacrals are undoubtedly opposite,
REVISION OF PALEOZOIC STELLEROIDEA. 951
and both dorsally and ventrally have the structure of Encrinaster. The adambulacrals are also opposite to the ambulacrals, and have long forward directed spines. In regard to the dorsal position of the madreporite, he states that the abactinal area has been mistaken for the actinal, and that therefore the madreporite lies upon the ventral side.
The disk is not circular in outline, but concave between the inter- radii.
LAPWORTHURA MILTONI (Salter).
Protaster miltont SAuTER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 330, pl. 9, fig. 4.—Wrieut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Pale- ontogr. Soc. for 1861), 1862, p. 32, fig. 18. —Hiaivenene Petrefactenkunde Deutschlands, vol. 4, 1876, p. 75, pl. 92, fig. 36.—Srirrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 148; Paleeontographica, vol. 32, 1886, pp. 79, 94, pl. 8, fig. 6
Lapworthura miltoni GreGorY, Proc. Zool. Soc. London for 1896, 1897, p. 1037, fig. 5.—Scu6nporr, Paleeontographica, vol. 57, 1910, p. 58; Jahrb. nassau- isch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 208.—So.as and Sotuas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 214, text figs. 1, 2,4 D, pl. 9, figs. 1, 2; pl. 10, figs. 1-4.—Sprencer, Mon. Brit. Pal. Aster- oz0a, pt. 1 (Palzontogr. Soc. for 1913), 1914, pp. 25, 32, 35, 36, pl. 1, fig. 9.
Formation and locality.—Abundant in the Lower Ludlow of the Siluric at Leintwardine, England. See elsewhere in this work (p. 237) under Stiirtzura leptosoma, which Schoéndorf states is but the young of L. miltoni. The same author states further that the latter species either embraces several species or the form has a long geologic range, for a number of species and genera appear to he idepacdl with L. miltoni.
Cat. No. 59394, U.S.N.M. LAPWORTHURA SOLLASI Spencer.
Lapworthura sollasi Spencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pl. 1, fig. 10.
Occurs in the Siluric of Great Britain. LAPWORTHURA (? ‘‘probably n. gen.’’) species (Miller and Gurley).
Aganaster (?) sp., Minter and Gurtiey, Sixteenth Rep. Geol. Surv. Indiana, 1891, p. 372, pl. 9, figs. 12, 13; authors’ extracts, 1890, p. 58.—GreEGory, Proc. Zool. Soc. London for 1896, 1897, p. 1038.
Original description.—‘ We have figured this fragment to show the anchylosis of the oral plates, and the pores passing through the ambulacral plates, and also those passing between them. It will be observed that one pore passes through each plate near the marginal
end, while a double row of pores passes between the plates in the central part of the arm furrow. We believe this is an Aganaster, from the depth of the central part of the disk, and the arrangement of the plates in the arm furrows; but the specimen is larger than any
252 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Aganaster gregarius we have seen and the rays are wider, and as we do not know the position of the pores in the rays of Aganaster, it may be our specimen does not belong to this genus.”
Remarks.—‘‘Seems to me to be allied to Lapworthura, and at least a member of the same family. It apparently has no ventral arm- plates, but an open furrow, and thus differs widely from Aganaster. It is probably a new genus.”’ (Gregory.)
Formation and locality—Not given. The specimen may be in the Gurley collection of the University of Chicago.
Genus STURTZASTER Etheridge.
Palzocoma Sauter (not D’Orbigny 1850), Rep. Brit. Assoc., 1857, Trans. of sec- tions, p. 76; Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, pp. 324, 327.—Wricurt, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, pp. 23, 29.—QueEnstepT, Petrefactenkunde Deutschlands, vol. 4, 1876, p. 81, pl. 92, fig. 43.—Zrrret, Handb. Pal., vol. 1, 1879, p. 453.—Srérrz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 152; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1898, pp. 45, 62.
Sturtzaster Eruertpcr, Rec. Australian Mus., vol. 3, 1899, p. 129.—ScHONDoRF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 217.
Genoholotype.—Palzocoma marstoni Salter.
Remarks.—Palzocoma = Stiirtzaster, Bdellacoma, and Rhopalocoma, all of Salter, are very poorly known, due to the fact that the specimens, though not rare, occur in a calcareous shale and are pressed flat till they have become a thin film of plates greatly obscured by an abun- dance of spines. Of P. marstoni, the genotype, the writer has seen five examples, presented to the United States National Museum by W. R. Billings. On the basis of the characters revealed by these specimens, he was inclined to leave the genus among the Asteroidea and in close association either with the Mesopaleasterinz (nearest Mesopalxaster, a phanerozonian), or the Schuchertiide (near Schuch- ertia, a cryptozonian).
The long, slender and serrated spines of Sttirtzaster are peculiar to the genus. In their abundance and character they remind one more of ophiurids than of asterids.
The figures of Salter and Wright, if correct, recall the large-disked eryptozonian genus Schuchertia, and it was this character that prob- ably also led Stiirtz to refer Stiirtzaster to the same group in asso- ciation with the genera Palasteriscus, Loriolaster, and Cheiropteraster.
Etheridge in 1899 called attention to the fact that D’Orbigny pro- posed in 18501 the new generic name Palzocoma for Ophiura miillert Phillips of the Lias. Ae name once proposed can not be used again in another sense, and therefore Mr. Etheridge is within the ile of nomenclature in substituting for Salter’s second usage of Paleocoma
1 Prodome, vol. 1, p. 240.
REVISION OF PALEOZOIC STELLEROIDEA. oe
the name of Stiirtzaster, with Palxocoma marstoni Salter as the genotype.
In 1910 Schéndorf was able to study ‘‘several right good examples”’ of S. marstoni, and strangely the form turns out not to be an asterid but an aulurid, with the essential ambulacral characters of Lap- worthura milton. He states that the ambulacrals are not alternate, as stated by Salter, but opposite one another. Therefore the ambulacrals and the adambulacrals are also opposite. The adam- bulacrals bear two or three spines on their outer edges, and Salter’s statement and figures showing two columns of ossicles outside of the ambulacrals appear to be very wrong. Schéndorf states that the peculiar preservation of the arm skeleton has given rise to this state- ment of Salter, and that there are only ambulacrals and adambula- crals present. The oral skeleton is distinctly adambulacral. A madreporite is not determinable.
On the dorsal side, all that can be clearly made out is the presence of ambulacrals and adambulacrals, all of which are arranged in trans-
verse rows. . STURTZASTER MARSTONI (Salier).
Palxocoma marstoni Satter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 328, pl. 9, figs. 3a-3c.—Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, p. 30, fig. 17.—QuENstTEDT, Petrefacten- kunde Deutschlands, vol. 4, 1876, p. 81, pl. 92, fig. 43.
Sturtzaster marstoni Scu6nvorF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 217.
Formation and locality —Common in the Lower Ludlow of Church Hill, Lemtwardine, England. Specimens are in many museums, the United States National Museum and the Yale Museum both having individuals. See S. coluint and S. cygnipes.
Cat. Nos. 60624, 60625, U.S.N.M.
STURTZASTER COLVINI (Salter).
Palxocoma colvini Sauter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 328.— Wriaut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, p. 30.
Sturtzaster colvini ScH6NvDoRr®, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 219.
Formation and locality.—In the Lower Ludlow, Leintwardine, Eng- land. ‘‘Probably completely identical with S.marstoni.”” (Schéndorf.)
STURTZASTER CYGNIPES (Salter).
Palxocoma cygnipes SALTER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 329.— Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Paleeontogr. Soc. for 1861), 1862, p. 30.
Sturtzaster cygniceps (sic) ScHénpdorr, Jahrb. nassauisch. Ver. Naturk., Wies- baden, vol. 63, 1910, p. 219.
Formation and locality.—Lower Ludlow, Leintwardine, England. “Probably completely identical with S. marstoni.” (Schdndorf.)
254 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
STURTZASTER (?) MITCHELLI Etheridge, jr. Sturtzaster (?) mitchelli Eruertee, jr., Rec. Australian Mus., vol. 3, 1899, p. 128,
Formation and locality —A single specimen from the Upper Trilo- bite bed of the Siluric (Wenlock series) at Bowning, New South
Wales. Genus BDELLACOMA Salter.
Palxocoma (Bdellacoma) SaurER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 324.—Wrriaut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Pale- ontogr. Soc. for 1861), 1862, p. 31.—Zrrrer, Handb. Pal., vol. 1, 1879, p. 453.—Stiirtz, Paleontographica, vol. 32, 1886, p. 96.
Bdellacoma Stiirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 46, 63.
Genoholotype and only species.—P. (B.) vermiformis Salter. Lower Ludlow, Leintwardine, England.
Remarks.—Until this form is restudied and brought up to date the supposed subgenus of Palzocoma has no value.
Genus RHOPALOCOMA Salter.
Palzocoma (Rhopalocoma) Saurer, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 329.—Wricut, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palee- ontogr. Soc. for 1861), 1862, p. 31.—Zrrren, Handb. Pal., vol. 1, 1879, p. 453.— Stiirtz, Paleeontographica, vol. 32, 1886, p. 96. Rhopalocoma Stiirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 46, 63. Genoholotype and only species.—P. (R.) pyrotechnica Salter. Lower Ludlow, Leintwardine, England. Remarks.—This form also requires modernization, and until then the supposed subgenus has no value.
Genus HALLASTER Sturtz.
Protaster Hatt (not Forbes), Nat. Hist. N. Y., Pal., vol. 3, 1861, p. 134; Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 293; rev. ed., 1868= 1870, p. 336.
Hallaster Sviirtz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 150.
Original description (Stirtz).—‘‘Ambulacral plates alternating [they are opposite]; the podial pores lie between these and the side plates. The dorsal skeleton consists of two columns of dorsal plates and two of lateral plates, of which the former adjoin medially along the rays. For P. forbesi Hall of the Silurian of North America I propose the generic name Hallaster, because on the one hand Forbes did not sufficiently characterize his Protaster, and on the other the above species in the sense of Salter’s Protaster is not congeneric with it.”
Genoholotype and only species.—Protaster forbesi Hall.
Remarks.—This genus appears to be most closely related to Lap- worthura. with the most obvious difference in the shape of the am-
REVISION OF PALEOZOIC STELLEROIDEA. 255
bulacral ossicles. In Hallaster the lateral wings of the plates curve round the podial openings proximally, while in Lapworthura they do so distally. Further, the side plates of the latter genus bear spines along their sides, while in the former genus they are restricted to the distal ends of the plates.
HALLASTER FORBESI (Hall). Text fig. 31.
Protaster forbesi Haut, Nat. Hist. N. Y., Pal., vol. 3, 1861, p. 134, pl. 7A, figs. _8-10; Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 293, pl. 9, figs. 5, 6; rev. ed., 1868=1870, p. 336, pl. 9, figs. 5, 6.—QuENsTEDT, Petrefacten- kunde Deutschlands, vol. 4, 1876, p. 134, pl. 95, fig. 13.—Sriirrz, Paleeonto- graphica, vol. 32, 1886, pp. 78, 83. Hallaster forbesi Stértz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 150.
The original description will not be repeated here because it is faulty and was later corrected by Hall.
Hall's description of 1868.—P. forbesi “has a circu- lar disk, composed of squamiform spiniferous plates and five long flexuous rays. These rays I have yf [originally] represented as composed, on the lower \e NO side, of a double range of [adambulacral] plates, as described and represented by Professor Forbes, but eo eae finding outside of these a range of small ossicles — rorprst (Hatt). Or- [side plates] to which are attached the spine bases, ce these have been shown as a part of an articulating spine (in the illustration, plate 7A‘), an unnatural representation, which I am now able to correct.
“In the species from the Lower Helderberg group, Protaster forbesi, the ventral surfaces of the rays are composed of an ambulacral and adambulacral series of plates on each side [there are no ventral ray plates]. The ambulacral plates are obliquely quadrangular and alter- nating in a slight degree [in the type they are opposite]; the adambu- lacral plates as seen from the lower side are narrow, elongate, oblique, and laterally imbricating, presenting the appearance of an oblique ridge with the anterior extremity projecting, and forming the point of attachment for the spines, with which each one is furnished. [These spines are striated longitudinally.] When the ray is abruptly curved, these plates project outward, sometimes almost rectangularly; and when at the same time the ambulacral area is obscured by adhering matrix, these plates might readily be mistaken for appendages of the inner ranges. The pores are comparatively large, truncating the outer adjacent angles of the ambulacral plates, while the base of one adambulacral plate and the side of another form the exterior margin. The centers of the upper sides of the rays are composed of
hy (Ra,
1 Nat. Hist. New York, Pal., vol. 3, 1861. 50601°—Bull. 88—15——-17
256 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
two ranges of subimbricating [dorsal] plates, which are closely joined along the median line; the marginal plates are the upper edges of the adambulacral plates, which bear on their anterior ends one, two, or three short spines.”’
Formation and locality —From the Coeymans member of the Hel- derbergian series of the Lower Devonic, at Jerusalem Hill, near Litchfield, New York. The holotype is in the American Museum of Natural History, No. 2302. There are two good specimens and a single arm in the Beecher collection at Yale University.
Genus SYMPTERURA Bather. Text fig. 32.
Sympterura BatHER, Geol. Mag., dec. 5, vol. 2, 1905, pp. 161-169, pl. 6, figs. 1, 2, 3, 6—Scubnvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 216.
Original diagnosis.—‘A Lapworthurid with spmulose disk ex- tending to second arm segment, with oral skeleton of teeth, long
Fic. 32.—SYMPTERURA MINVERI, AFTER BATHER. A. SEMIDIAGRAMMATIC RECONSTRUCTION OF SYN- GNATHS, X 10. B. RECONSTRUCTION OF SEVENTH AND EIGHTH ARM SEGMENTS, X18: @, DISTAL, AND b, PROXIMAL PORTION OF VERTEBRA; C,'ADAMBULACRALIA; DP, PODIAL DEPRESSION; ¢, INTERSPACE, OCCU- PIED, AT LEAST IN PART, BY INTERVERTEBRAL MUSCLES.
jaws, and short mouth frames (torus not seen), with free arm seg- ments containing a vertebral ossicle, possibly compound, grooved ventrally and provided on each side with two wings, to the distal of which is attached an adambulacral spiniferous element.”’
Genoholotype and only species—S. minvert Bather (same references as above). The holotype was found in the Devonic (?Lower) at Epphaven, near Padstow, North Cornwall, England.
As this specimen presents in the ambulacralia characters of great value in the morphology of the Ophiurid vertebre, it is advisable to quote here somewhat extensively from Bather’s statements.
“The median body of each segment is undoubtedly the equivalent of the normal Ophiurid vertebra. On the accepted theory that this vertebra was evolved by the fusion of a pair of ossicles originally alternating, then opposite, and finally joined along the middle or
REVISION OF PALEOZOIC STELLEROIDEA. od
radial line, the present specimen may be described as in a stage of development later than the fusion, but possibly retaining in the median groove a trace of the primitive distinctness of the ossicles. Those ossicles are usually described as ambulacral, and that term may be accepted so far as it denotes homology with the ossicles so named in an Asterid. * * *
“As a rule among Ophiurids in this stage of evolution, each ver- tebra has on each side a single side process on which abuts an outer ossicle, the so-called adambulacral, and these adambulacrals, which bear the lateral spines, alternate with the ambulacral ossicles or vertebre. It is a little dificult to interpret the appearances of the present specimen in harmony with such an arrangement. On the assumption that each segment should contain one ambulacral pair (here fused) and one adambulacral pair bearing spines, ray 7 has been assigned nine segments. But each such segment is seen to have two processes on. each side, and the distal one of these bears the spines. For this reason, and because of the appearances in segment 8, it may be supposed that the outer spiniferous portion of the distal process (c in fig. 1) is an adambulacral element. What, then, is the proxi- mal side process? To this question two possible answers present themselves. .
‘The appearance of a transverse division in the vertebra, between the proximal and distal processes, suggests that each segment really consists of two ambulacral pairs, of which only the distal one is associated with adambulacrals, the proximal pair of adambulacrals being suppressed. Each of these supposed ambulacral pairs pos- sesses a single pair of lateral processes, but those of the distal pair are partly overlaid by the adambulacral elements. In the distal region of the ray the proximal and distal halves of the vertebra are distinguishable; but nearer the disk and within it they have come closer together, the transverse division has disappeared, and the side processes are reduced to structures which appear as bars, but are probably flattened lamine. Thus the vertebrae seen inray v are, on this explanation, of compound origin. * * *
‘““Now, comparison of the vertebrae of recent Ophiurids with the arm segments, especially the proximal ones, of our fossil leaves no room for doubt that the depression marked p is for the reception of a podium, while that marked q is for the insertion of the ventral intervertebral muscles. A single arm segment of a recent Ophiurid, such as Ophi- arachna or Amphiura, is therefore homologous with any one of the whole segments here numbered 1-8. If one of these is really com- posed of a distal and a proximal half (lettered a and b respectively in figs. 1 and 2) the same statement would apply to the recent Ophi- urid, and some trace of this origin might be seen in the development.
258 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
The observations of Prof. Ludwig! and Mr. J. W. Fewkes? on Amphiura squamata have shown that the two lateral halves of each vertebra unite first at the proximal and distal ends, leaving a space between. This is suggestive of an origi from proximal and distal elements. On the other hand each lateral half sprmgs from a single center of calcification, from which it stretches out in a distal direction, so that the incipient ambulacral element is thicker at its proximal end. This last-mentioned feature is paralleled by. the boot-shaped proximal portions of the ambulacral ossicles in. the Prot- asteride. At a slightly later stage the ambulacral of Amphiura broadens at the distal end, which thus comes to resemble the distal portion of the Protasterid ambulacral. If this distal portion in Amphiura were, as indicated by Prof. Ludwig’s observations, merely an extension of the proximal portion, then it might be inferred that the whole structure, both here and in the various Paleozoic forms alluded to, represented a single ambulacral pair and not two successive pairs. In such case one would accept Dr. Gregory’s suggested explanation® ‘that the smaller pieces are only triangular, distal portions of the ambulacral ossicles, apparently separated from the proximal portion[s] by a groove.’ Dr. Gregory further sug- gests that these grooves or depressions ‘were for the lodgment of the ventral muscles which moved the arms.’ A far more probable explanation surely is that they were for the reception of the branches from the radial water-vessel to the podia. This explanation, how- ever, consonant as it is with the facts of development of Amphiura, reminds one of another difficulty. Prof. Ludwig* has pointed out that, whereas the so-called ambulacrals of Asterids lie at right angles to the perradius and between the successive branches and podia, those of Ophiurids lie parallel to the perradius and across the branches to the podia. Now, if, as we have every reason to believe, the Ophi- urids were derived from Asterids, it is hard to see why this change should have taken place. That is the difficulty, but it is a difficulty that disappears if we suppose that the vertebra is really compounded of two successive ambulacral pairs in the manner outlined above. The remaining objection to this latter hypothesis is that, as Dr. Gregory has pointed out, it postulates the suppression of alternate podia. Nevertheless, similar fusion and concomitant suppression are not so unknown among Echinoderms as to render this objection a fatal one.
“The suggestion that the vertebre of Ophiurids are composed of two successive ambulacral pairs certainly can not be proved with
1 Zeits. wiss. Zool., vol. 36, 1881, p. 181.
2 Bull. Mus. Comp. Zool., vol. 13, No. 4, 1887.
3 Proc. Zool. Soc. London for 1896, 1897, p. 1032. 4 Op. cit., p. 185. ;
REVISION OF PALEOZOIC STELLEROIDEA. 259
the evidence at our disposal. But it is doubtful whether it can be disproved, and I therefore make it to promote a search for further evidence pro or con.
“Tyo other features in the present specimen need discussion, and may perhaps throw light on the problem just posed. The first of these is the fact that the broadest and stoutest portion of each arm segment appears to be the distal half (marked a in fig. 1), whereas in the developing Amphiura and in the adult Protasteridz the reverse is the case. This character is also found in Furcaster paleozoicus as figured by Mr. Stiirtz, im Ptilonaster princeps of J. Hall, and in Lapworthura Miltoni, as interpreted by Dr. Gregory. (See our fig. 4 [80].) In the Epphaven fossil the feature is to some extent accounted for by the supposed fusion of a spiniferous adam- bulacral element with the distal wing of the ambulacral; but in Lapworthura and Furcaster this wing, while unconnected with the adambulacral, is still more preponderant. In some other early Paleozoic genera, e. g. Eugaster, J. Hall, and FKophiura, Jaekel, the wing is neither distal nor proximal, but arises half way up the ambulacral, so that one can not say to which of two successive seg- ments the podium belongs; in fact, the structure is in this respect absolutely that of an Asterid.' These differences call for some explanation. Starting from the indifferent Ordovician type of Eophiura, we may suppose that in one series of genera (e. g. Protas- teride) the wing moved toward the mouth, while in another series (e. g. Lapworthuride) it moved away from the mouth. In both series the podium ultimately became inclosed within the substance of (apparently) a single ossicle; but, if this took place by a sub- sequent lateral outgrowth of stereom, then in the former case the vertebra must have inclosed a podium distal to itself, and in the latter case a podium proximal to itself. Thus the relations of the vertebrae to the podia would be fundamentally different in the two lines of descent. On the other hand, alternate podia may, as suggested on a previous page, have been inclosed by the union of successive pairs of vertebra, and this type of structure may be the one seen in process of development in the arm segments of our fossil, and the one that persisted to the present day.
“The second feature worthy of attention is the considerable space that seems to intervene between the distal wing of one seg- ment and the proximal wing of the next. This is conspicuous in the distal region of ray i, where, further, the depression (g in fig. 1 [82 B]) markedly resembles the podial depression (p in fig. 1), and differs from it mainly in being rather nearer the axis of the arm. The theory that the Ophiurids are descended from Asterids does not
1 See Jaekel, Zeits. geol. Ges., vol. 55, Protok., 1904, pp. 106-113.
260 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
explain the evolution of such an interspace, and the general tendency to shortening and approximation of the vertebre, shown in the history of the Ophiurids, leads one to mquire why there should ever have been introduced a stage in which, as in the Devonian Ophiurina, the recent deep-sea Ophiohelus, and the young Amphiura, the vertebrae have so far departed from the primitive type as to become axially elongate. This stage has been regarded as primi- tive by Lyman, Ludwig, and other zoologists, but in theory and fact it is ‘primitive’ only so far as the later forms are concerned, while with reference to the complete series it is ‘intercalated.’
“Recurring to the hypothesis that the vertebrze are compounded of successive pairs of ambulacrals, we find in it an explanation not merely of this curious elongation of the arm segments in general, but of the interspaces between them in this genus (lettered g). An objection to the hypothesis was the necessity for assuming the sup- pression of alternate podia. Here, it may be, is evidence of a stage in which those podia were not yet suppressed, though perhaps somewhat atrophied. If both depressions (p and q) were for the reception of podia, then their alternate approximation to and re- moval from the perradius may be compared with the similar phe- nomenon in Asterids.
“Whether the features just discussed be or be not accepted as evidence in favor of the compound origin of the Ophiurid vertebra, they demand some explanation; and it may be added that the same hypothesis will perhaps furnish an equally needed explanation for the hitherto unexplained differences that obtain between Paleo- zoic genera of Ophiurids in the relations of the adambulacrals to the ambulacrals.
“The origin of the Ophiurid mouth-skeleton also may be illu- minated by the preceding hypothesis, which is in full harmony with the opinion that many more arm segments enter into the composition of that structure than is the case in Asterids, an opinion based on embryological research by Dr. O. zur Strassen, and on paleonto- logical investigation by Dr. O. Jaekel in the paper quoted above. In this region of the ray, at any rate, adambulacrals and podia must have been suppressed in all Ophiurids. We may here note the apparent absence from our specimen of the adambulacral elements known as side mouth-shields, as well as of the peristomial plates. The latter are wanting in most early Ophiurids, a fact confirmatory of Dr. zur Strassen’s conclusion that they are not ambulacral elements, but ‘secondary calcifications confined to the interradial region.’ ”’
Schéndorf states that the structure of the arms is like that in Lapworthura miltoni and the oral armature as in Encrinaster.
1 Zool. Anzeiger, vol. 24, 1901, p. 609.
REVISION OF PALEOZOIC STELLEROIDEA. 261
Genus FURCASTER Sturtz.
Furcaster Stirrz, Paleontographica, vol. 32, 1886, p. 79; N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 148; Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 25.—Greeory, Proc. Zool. Soc. London for 1896, 1897, p. 1038; Treat. Zool., vol. 3, Echinoderma, 1900, p. 275, fig. 31.
Disk small, circular. Rays five, short, narrow, tapering gradually, and slightly flexible. Actinally flat and abactinally rounded. There is a dorsal median column of slightly projecting plates and two lateral ranges of side plates. The dorsal plates are medially depressed, with their outer sides extended into ears, into which fit the spine-bearing side plates.
‘‘Ambulacral ossicles [opposite] of a long central body and two short wings, which are attached only to the anterior corner of the ossicle.”” (Gregory.) Buccal scutes smail.
Genoholotype.—F’. palxozoicus Stirtz. IF. (?) daoulasensis (Davy) may also belong here.
Remarks.—‘‘In Stiirtz’s description he refers to the existence in this genus of ventral arm plates, and even figures them. His type- specimens are now in the British Museum, but I can not verify the existence of any ventral arm plates.” (Gregory.)
FURCASTER PALAOZOICUS Stiittz.
Furcaster palxozoicus Srirrz, Paleontographica, vol. 32, 1886, p. 79, pl. 8, figs. 4, 5; N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 148; Palzontographica, vol. 36, 1890, p. 214.—GrercGory, Proc. Zool. Soc. London for 1896, 1897, p. 1038.
Formation and locality—In the Lower Devonic roofing slates, Bundenbach, Germany. There are three specimens of this species at Yale University.
Cat. No. 59383, U.S.N.M.
FURCASTER (?) DAOULASENSIS (Davy).
Protaster daoulasensis Davy, Bull. Soc. géol. France, ser. 3, vol. 14, 1887, pp. 182- 187, text figs—Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1038, footnote (‘‘is an ally of Furcaster’’).
Formation and locality—From the Lower Devonic, Rumguen, near Brest, France.
Genus PALASTROPECTEN Sturtz.
Palastropecten Stiirrz, Paleeontographica, vol. 32, 1886, p. 88, pl. 10, figs. 3, 4; vol. 36, 1890, p. 213, pl. 26, figs. 12, 13.—Greeory, Proc. Zool. Soc. London for 1896, 1897, p. 1038.
Palxspondylus Srirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 190.
Palxospondylus Sttirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 191, 202.
Diagnosis by Gregory.— Disk circular, large (badly preserved in the specimens; probably originally soft and irregular). Arms thick,
262 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
broad, and somewhat lanceolate in shape. Ambulacral ossicles narrow, the lateral wings resting on the whole body of the ossicle.”
Genoholotype and only species.—P. zittela (Stiirtz) (citations as above). In the Lower Devonic, Bundenbach, Germany.
Family EOLUIDIIDE Gregory.
Eoluidiide Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1038.
Eophiuride Sttrtrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 203.—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Original diagnosis.—‘‘Streptophiuree with the ambulacral ossicles united to form vertebral ossicles. Ventral arm plates present, but there are no buccal shields. (Dorsal arm plates present only in the highest genus.)
‘“‘Remarks.—This family includes three Devonian genera, which differ from the previous families of this order by the presence of ventral arm plates and by having vertebral ossicles, which articulate (? always) by simple rounded pits and processes. The family differs from living Streptophiure by the absence of buccal shields and the simplicity of the oral armature.”
Contains the genera:
Holuidia Stiirtz. Eospondylus Gregory. Miospondylus Gregory.
Genus EOLUIDIA Sturtz.
Asterias asperula RorMER (part), Paleeontographica, vol. 9, 1863, p. 146, pl. 24, figs. 1-5; pl. 26, fig. 6; pl. 27.
Eoluidia Stiixtz, Paleeontographica, vol. 32, 1886, p. 89, pl. 11, figs. 1, 2; vol. 36, 1890, p. 211, pl. 26, figs. 10, 11.—Grercory, Proc. Zool. Soc. London for 1896, 1897, p. 1038.—Sorzas and Sorzas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 226, fig. 4E.
Eophiurites Sturrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 190.
Diagnosis.—‘‘ Disk rather large; the interbrachial outlnes are deeply concave. [Rays very long, slender, and fragile.] Each syngnath consists of pairs of mouth frames and jaws; a jaw plate is present. The vertebral ossicles are small and the union of the two lateral elements incomplete; the lateral wings are thin. The adambulacral plates are triangular and each of them bears several spines. The pores for the podia occur at the middle of the lateral margin of the ventral arm shields.”’ (Gregory.)
Genoholotype and only species.—E. dechent Stirtz (citations as above). Lower Devonic, Bundenbach, Germany.
Cat. No. 35116, U.S.N.M.
REVISION OF PALEOZOIC STELLEROIDBA. 263
Genus EOSPONDYLUS Gregory.
Ophiurella Stirtz (not Agassiz, 1834), Paleeontographica, vol. 32, 1886, p. 77. Eospondylus GRrrGory, Proc. Zool. Soc. London for 1896, 1897, p. 1039.
Original diagnosis.—‘ ‘Disk circular. Ambulacral ossicles com- pletely fused into vertebral ossicles, each of which, however, is trav- ersed by a pore. The adambulacral ossicles are somewhat pear- shaped. The podial pores are at the posterior angles of the ventral arm plates.”
Genoholotype and only species.—Ophiurella primigenia Stiirtz.
EOSPONDYLUS PRIMIGENIUS (Stiirtz). Ophiurella primigenia Sriirrz, Paleontographica, vol. 32, 1886, p. 77, pl. 8, figs. 1, 2; vol. 36, 1890, p. 210, pl. 26, figs. 6, 7. Eospondylus prumigenia Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1039.
Formation and locality.—Lower Devonic, Bundenbach, Germany.
Genus MIOSPONDYLUS Gregory. Ophwra rhenana StiRtz, Verh. naturh, Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 29, pl. 1, figs. 1-3. Miospondylus rhenanus GREGORY, Proc. Zool. Soc. London for 1896, 1897, p.
1039.—Sotias and Soxuuas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 226.
Onginal diagnosis (Gregory).—‘‘Disk circular. Ambulacral ossi- cles completely united; each half of the vertebral ossicle is boot- shaped. The oral angles each consist of a pair of synenaths without jaw plate. The ventral arm plates are small and are not notched by podial pores.”
Genoholotype and only species —Ophiura rhenana Stirtz (citations as above). Lower Devonic, Bundenbach, Germany.
Remarks.— Eospondylus and Miospondylus “agree in family char- acters with Holwidia, but differ from it in the structure of both the ambulacral and adambulacral plates.’”’ (Gregory.)
Family AGANASTERID® Stiirtz.
Aganasteride Stiirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 203.—Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Genus AGANASTER Miller and Gurley.
Aganaster Minter and Guruey, Sixteenth Rep. Geol. Surv. Indiana, 1891, p. 372; authors’ extracts, 1890, p. 57.—Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1039.
Ophiopege Boum, Zeit. geol. Gesell., vol. 45, 1893, p. 159 (same genoholotype as for Aganaster).
Original description.— ‘In 1869 Meek and Worthen described an Ophiuroidea, in the Proceedings of the Academy of Science of
264 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Philadelphia, page 169, under the name of Protaster gregarwus, which they redefined and illustrated in the Geological Survey of Illinois, volume 5, page 509, under the name of Protaster (?) gregarius. ‘They had numerous specimens ‘in the condition of casts and molds, in a very fine, somewhat granular matrix, that did not show the details of its structure very clearly,’ but they said, ‘It will probably be found to be generically distinct from the Silurian typical forms of Protaster, but we prefer to place it provisionally in that genus for the present.’ In the collection of Mr. Gurley there are several specimens belonging to this species, and they show a few characters not ob- served by Meek and Worthen, and demonstrate very clearly this species does not belong to the genus Protaster; we therefore propose to include this species in a new genus, Aganaster, and describe the characters, so far as known, as follows:
‘‘General outline, a central circular disk with five long, narrow rays; the circular disk on the dorsal side is covered with small polygo- nal plates which are not interrupted by the presence of the rays, thus showing the disk had a depth greater than the depth of the rays; rays very narrow and convex or half cylindrical, spine bearing, gradually tapering, and from the dorsal side appear as if composed of plates arranged exactly opposite each other; the ventral side shows a rather deep central disk with marginal plates. There are 10 oral plates in the central part of the disk.”’
Genoholotype and only species.—Protaster gregarius Meek and Worthen.
Remarks.—Aganaster ‘‘has nothing to do with Protaster and is clearly a member of the Streptophiure. As far as its characters are known to me it must be included among the Eoluidiide. It differs from the rest of this family by the presence of dorsal arm plates. * %* + Bohm has founded the genus Ophiopege on the type species of Aganaster.” (Gregory.)
AGANASTER GREGARIUS (Meek and Worthen).
Protaster ? gregarius MreK and WorrHeEn, Proc. Acad. Nat. Sci. Philadelphia, vol. 21, 1869, p. 169; Geol. Surv. Illinois, vol. 5, 1873, p. 509, pl. 16, fig. 5.
Alepidaster gregarius Merx, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 275 (gen. ref. only).
Aganaster gregarius Miter and Guriey, Sixteenth Rep. Geol. Surv. Indiana, 1891, p. 372, pl. 9, figs. 10, 11; authors’ extracts, 1890, p. 57, pl. 9, figs. 10, 11.—Miiter, N. Amer. Geol. Pal., 1st. App., 1892, p. 673, fig. 1208.
Description of 1873.—‘‘The disk of this species is circular in out- line, slightly convex above, and measures from 0.20 to 0.30 inch in diameter. In most cases it looks as if merely covered by a smooth, membranaceous integument. Some casts of its external surface, however, seem to show traces of flat, nearly smooth, imbricating scales above. The five arms are slender, flexible, and rather long
REVISION OF PALEOZOIC STELLEROIDEA. 265
in proportion to breadth. In a specimen with a disk measuring 0.25 inch in breadth, the diameter of the arms near the disk is only 0.05inch. None of the specimens show the entire length of the arms, though some fragments of them were seen lying detached in the matrix, about 0.55 inch in length, without being complete at either end. From the breadth and gradual taper of these, it would seem probable that when entire they may have been 0.75 to 1 inch in length. Their impressions in the matrix give no indications of a longitudinal furrow along the under side, but show that there were about six pairs of arm pieces in a length of 0.16 inch. These pieces appear to be nearly though not exactly opposite, and each one provided below with a comparatively large, round, deep pit, or pore, near the middle of its anterior side. Along their lateral margins there appear to be impressions in the matrix of very small spines (one to each arm piece), though if such, they must have been extremely short. Impressions of the upper side of the slender arms show them to have been somewhat rounded above, with the nearly square arm pleces slightly alternating. Some of the impressions seem to show traces of central pores or pits, one at the middle of each pair of pieces, though in others no traces of these are visible.”
Formation and locality—Common as molds in a fine impure sandstone and in the famous crinid bed at Crawfordsville, Indiana, in the Keokuk formation of the Mississippic.
There are two specimens (No. 6) of this species in the Wachsmuth collection at Harvard University. At Yale University there are four specimens.
Family CHOLASTERID Worthen and Miller.
Cholasteride WorTHEN and MruER, Geol. Surv. Illinois, vol. 7, 1883, p. 328.
Original definition.—Cholaster ‘‘is so widely different from those heretofore discovered that we think it belongs to a distinct family, which might very appropriately be designated the Cholasteride, but until other specimens have been found showing other parts of the body, we prefer to let the family remain undefined.”
Contains the genus:
Cholaster Worthen and Miller.
Genus CHOLASTER Worthen and Miller.
Cholaster WortHEN and MitiEr, Geol. Surv. Illinois, vol. 7, 1883, p. 328.— GreGory, Proc. Zool. Soc. London for 1896, 1897, p. 1040.
Original description.—Dorsal side alone known. ‘‘Body trun- cated pentagonal, central area circular, deep and large in propor- tion to the rays; rays distant, small, short and abruptly truncated.
266 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
‘‘Dorsal side possessing a rather large centro-dorsal plate, which is surrounded by five plates occupying the position of radials, while the other part is covered with numerous small disk plates.”
Genoholotype and only species.—C. peculiaris Worthen and Miller.
Gregory states that Cholaster ‘‘appears to be allied to Aganaster, but the structure of the ambulacral ossicles is unknown.”
CHOLASTER PECULIARIS Worthen and Miller.
Cholaster peculiaris WorTHEN and Miter, Geol. Surv. Illinois, vol. 7, 1883, p. 329, pl. 31, figs. 4a, 4b.
Original description.—'‘The general form of the body is that of a truncated pentagonal star, with a large circular disk. A centro- dorsal plate is surrounded by five others, all of which are much larger than other plates of the body, and occupy a centro-dorsal depres- sion. The position of these five plates is that of radials, resting upon a basal, and therefore all other plates of the body might be regarded as radials and interradials, the latter bemg very numer- ous, because of the wide separation of the rays at their junction with the body. The interradials are polygonal, convex, or sub- spinous plates, without much variation in size whether filling the larger or smaller interradial spaces. The plates following the larger radial plates, as above defined, in the direction of the rays, are not, however, by their form or arrangement to be distinguished from the interradials, though differing from those forming the rays. The plates covering the dorsal side are thus divided into three kinds, viz.: First, the larger plates filling the centro-dorsal depres- sion; second, the disk plates which cover all other parts of the body except the rays, and, third, the plates which cover the rays proper, which in this species are easily distinguished from the central disk plates.
“The rays are short, abruptly truncated, and slightly expanded at the apices by reason of an enlargement of the terminal plates. They are widely separated from each other, though not at uniform distances, and present the appearance of having been stuck on the central disk, instead of having grown from it, an appearance more marked, by reason of the change in the form of the plates, from the disk to the rays.
‘‘One of the interradial spaces is much greater than the others, so that a line may be drawn across the disk, leaving three entire rays upon the smaller half. The back of each ray is covered by .a series of transversely elongated plates separated from the side series by a longitudinally impressed line. A single series of plates covers either side of a ray, interlocking with the transverse dorsal series and directed backward toward the disk.
“The oral plates are unknown, and no madreporiform tubercle has been detected.”’
REVISION OF PALEOZOIC STELLEROIDEA. 267
Formation and locality—Okaw Bluffs, between Chester and Kaskaskia, Illinois, in the Chester formation of the Upper Missis- sippic. The holotype is in the Illinois State collection, No. 2480.
Subclass OPHIUROIDEA.
These animals are not present in the older Paleozoic, may have appeared in the late Devonic, and do not seem to have been abundant
d.
: lt
AS
Fic. 33.—OPuHIOTERESIS. AFTER BELL FROM GREGORY. FIG, 34.—SYNGNATHS OF OPHTURA CILIARIS. ABORAL SURFACE OF AN ARM OSSICLE: @, ARTICULAR AFTER MULLER FROM GREGORY. j, JAW; CAVITIES; d, THE DOUBLE DORSAL SHIELDS; 1, LATERAL m.f., MOUTHFRAME; 2. g., GROOVE FOR CIR- ARM PLATES. CUM@SOPHAGEAL NERVE-RING; 7p.d., PORE
AND DEPRESSION FOR ORAL TENTACLE,
before the Triassic, since which time they occur more and more com- monly. In the present oceanic waters they are popularly known as sand-stars, brittle-stars, branching-stars, or basket starfish. They range from shallow and estuarine waters to abyssal depths. Typical Ophiuroidea differ from typical Asteroidea in having the arms sharply marked off from the disk as appendages, and in the absence of grooves along the actinal side of the arms. This means that the body cavity which in the Asteroidea extends out into the rays is restricted in the Ophiuroidea to the disk.
The subclass Ophiuroidea is defined by Schéndorf as follows:
‘‘Ambulacral water-vascular system situated in a small groove at the base of the ray ossicles, and ventrally covered by a single column of ventral shields. From the radial canal outside of the ambulacrals arise simple lateral branches that never have ampulle, as a rule curve upward, pass into and through the substance of the ossicles, and finally open out laterally between the ventral and side shields as the ambulacral podia. Ambulacrals opposite, each right and left piece coossified into a vertebra with complicated articular surfaces [see figs. 34-36]. Adambulacrals transformed into lateral shields. Vertebre dorsally covered by a single column of dorsal shields.” Disk circular in outline, ‘‘without marginal plates, and sharply separated from the rays, that as a rule are rounded. There is no typical madreporic plate. One of the ventrally situated mouth shields serves as madreporite’”’ (1910a: 246).
268 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
In ophiurids the oral skeleton, or syngnaths, is composed of three pairs of adambulacrals and ambulacrals. Of these the two first pairs alone are prominent and preserved. The third pair remains internal, small, and rudimentary.
Family ONYCHASTERID Miller.
Onychasteride Mutter, N. Amer. Geol. Pal., 1889, p. 216.—GreGory, Proc. Zool. Soc. London for 1896, 1897, p. 1040.—Sriirtz, Verh. naturh. Ver. preuss. Rheinl., ete., vol. 56, 1900, p. 202.—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 235.
Original diagnosis.—‘‘Streptophiure with well-developed vertebral’ ossicles, and with very flexible, contorted, unbranched arms; there
35
Fias. 35 AND 36.—VERTEBRAL OSSICLE OF OPHIURA CILIARIS. AFTER MULLER FROM GREGORY. 35; ABORAL SURFACE; 36, ADORAL SURFACE. C, CANAL FOR THE PODION (SHOWN BY REMOVAL OF A PART OF
MUSCLE FIELD ON RIGHT SIDE); l.m., LOWER MUSCLE FIELD; /.f., LOWER AND w.f., UPPER CANAL FURROWS, U., UMBO}; U. 8., UMBONAL SOCKET.
are no external arm plates, the integument containing granules only.”
Contains the genus: Onychaster Meek and Worthen.
Genus ONYCHASTER Meek and Worthen.
Onychaster Mux and WorrueEn, Geol. Surv. Illinois, vol. 3, 1868, p. 526; Proc. Acad. Nat. Sci. Philadelphia, vol. 21, 1869, p. 82; Geol. Surv. Illinois, vol. 5, 1873, p. 474.—Zrrrey, Handb. Pal., vol. 1, 1879, p. 443.—Mituer, N. Amer. Geol. Pal., 1889, p. 264.—Srirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 30.—GreEcory, Proc. Zool. Soc. London for 1896, 1897, p. 1040.—Sriirtz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 183. —Scuénvorr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, pp. 47-61, vol. 63, 1910, p. 240; Palzontographica, vol. 57, 1910, p. 59.— Spencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleontogr. Soc. for 1913), 1914, pp. 26, 50.—I. B. J. Soxzas, Philos. Trans. Roy. Soc. London, ser. B, vol. 204, 1913, p. 51.—Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 66, 1913, pp. 97-114.
REVISION OF PALEOZOIC STELLEROIDEA. 269
Genoholotype.—O. flexilis Meek and Worthen.
For generic description, see under O. flexilis.
Remarks by Gregory..—‘‘This interesting genus has hitherto been placed among the Euryalide, of which it has been regarded as the best known fossil representative. As Prof. Bell, however, has remarked, Meek and Worthen’s clear figures of the vertebral ossicles show that the articular surfaces are Streptospondyline and not Cladophiuroid.”’
Schéndorf in 1909 restudied Onychaster in detail, and came to the following conclusions:
‘“Onychaster flexilis shows plainly in the structure of its arm ossicles that it belongs to the Ophiuroidea. As in this subclass, so also in Onychaster the arm ossicles originated from two halves (ambulacrals) that grew tightly together. When compared with living Ophiurids, this
Fias, 37-41,.—ONYCHASTER FLEXILIS. AFTER SCHONDORF, 37 AND 38, PROXIMAL VERTEBRA SEEN FROM THE ABORAL AND ADORAL SURFACES, 39, VENTRAL VIEW OF TWO PROXIMAL VERTEBRAE, ORIENTED WITH THE ABORAL SIDE UP AND THE ADORAL DOWN. 40, SIDE VIEW OF SAME. ADORAL SIDE ON LEFT, ABORAL ON RIGHT. 41, VENTRAL VIEW OF SEVERAL SUCCESSIVE VERTEBRA WITH THE ABORAL SIDE AT THE TOP, d@, UPPER LATERAL ARTICULAR KNOB; a’, SOCKET FOR KNOB OF ADORAL SIDE; Cc, INSERTION FIELD FOR THE UPPER, AND g, FOR THE LOWER INTERMEDIARY VERTEBRAL MUSCLES; g7, MEDIAN UN- PAIRED DEPRESSION; gr 1, SMALL DEPRESSION FOR THE KNOB, ki, OF THE ADORAL SIDE; gf's, LARGE DE- PRESSION OF THE CENTRAL AREA OF VERTEBRA, ™, BARRIER SEPARATING THE UPPER AND LOWER INTERMEDIARY VERTEBRAL MUSCLES; 7, LATERAL GROOVE (? FOR LATERAL BRANCHES OF WATER- VASCULAR SYSTEM); $, VENTRAL PROJECTION OF THE LATERAL KNOBS OF ADORAL SIDE; t AND t!; UNPAIRED MEDIAN ARTICULAR KNOB AND SOCKET.
amalgamation of the two arm ossicles in Onychaster is still plainly to be
seen. The equivalent skeleton of the adambulacrals in the asterids is
not yet completely separated from the arm ossicles nor developed into independent side or lateral shields; on the contrary, they still remain attached and in articulation with the arm ossicles on their ventral outer margin. On their somewhat fluted outer margin they bear afew spines.
The arm ossicles are not externally naked but are covered by smaller
additional plates that bear flat calcareous particles. Individual large
dorsal shields do not appear to be present, for on the large Berlin speci- men the arm ossicles lie directly beneath the small flat dorsal plates.
Only in the distal part of the rays does one observe some rows of
*
270 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
apparently independent dorsal plates, that overlie one another in a scalelike manner, but this determination needs to be substantiated on better preserved material. Along the median line of the arm ossicles there lies ventrally a single column of ventral plates, that bear spines and externally cover the radial canal of the water vas- cular system. The lateral branches from the radial canal to the ambulacral podia do not penetrate the substance of the arm ossicles as in living ophiurids, but lhe between each pair of vertebre. The oral skeleton consists of five interradially placed mouth-corner pieces. Each one of these is made up of three elements, the two outer of which are united into pairs’’ (pp. 60-61). Contains the following species:
O. flexilis Meek and Worthen. Keokuk.
O. asper Miller. Keokuk. |
O. barrist (Hall). Burlington.
O. confragosus Miller. Keokuk.
O. demissus Miller. Keokuk.
ONYCHASTER FLEXILIS Meek and Worthen. Text figs. 37 to 42.
Onychaster flecilis MEEK and WortHEN, Geol. Surv. Illinois, vol. 3, 1868, p. 526, figs. A-D; Proc. Acad. Nat. Sci. Philadelphia, vol. 21, 1869, p. 83; Geol. Surv. Illinois, vol. 5, 1873, p. 510, pl. 16, figs. 3a-31.—Zirren, Handb. Pal., vol. 1, 1879, p. 444, fig. 314.—MintEr, N. Amer. Geol. Pal., 1889, p. 264, fig. 374.— Scuénporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 62, 1909, pp. 47-61; vol. 63, 1910, p. 240.—I. B. J. Soruas, Philos. Trans. Roy. Soc. London, ser. B, vol. 204, 1913, pp. 51-62, text figs. 1-4, pl. 8, figs. 1-6.— Scuinporr, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 66, 1913, pp. 97-114, text figs. 1, 2, pl. 3, figs. 3-9—Srencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, pp. 26, 50.
Original description.—‘‘The interesting fossil on which we propose to found this genus and species seems to differ so widely, in some of its characters, from the true starfishes, as well as from the Ophi- urians, as to leave doubts whether it can be properly placed in either of these groups as now understood. * * * In habit and general appearance it most nearly resembles the Ophiurians, from which, however, it differs widely in structure. It is composed of a rather small subdiscoid body, and five long, slender, rounded, flexible arms or rays. In nearly all of the specimens yet found the arms are folded together like the claws of a bird when grasping some small object. A few of them, however, have the arms opened out more or less, so as to show that they were very flexible, or capable of being moved about in all directions. They usually increase slightly in thickness for a short distance from the body, then taper very gradually to their extremities, being about 2.50 inches in length, and 0.22 inch in breadth, at the widest part.
REVISION OF PALEOZOIC STELLEROIDEA. 271
‘On the dorsal side of the body * * * there is seen a compar- atively large circular area or disk, composed of an outer circle of ten rather prominent pieces, united together in five pairs by close-fitting sutures, each piece being pierced by a round ovarian? pore. Imme- diately within this circle there is, apparently, another circle of ten smaller pieces, also united in five pairs, but without pores; and within this latter circle there is a third range of five still smaller, nonporif- erous pieces, surrounding a central anal? opening; the whole re- minding one of the apical disk of an Echinoid, though differing in structure from this part of the known types of that group. It is also worthy of note that there is some analogy between this disk and the body of a crinoid, excepting that there is a central opening, and that the first division of the radial series takes place immediately on the inner range of pieces corresponding to the basal pieces of a crinoid, while all of the third range of pieces are pierced by pores. * * *
“Immediately outside of the circle of ten pore pieces, mentioned above, each pair of these pieces is succeeded by two or three pairs of differently formed, interlocking, transverse pieces, in direct range, con- necting them with the dorsal side of each of the five rays. <A little far- ther out the dorsal side of the rays, these transverse pieces are seen to become disconnected by more or less wide spaces, and gradually pass into pairs of lanceolate pieces, deeply furrowed longitudinally, while between the inner ends of the two pieces of each pair there appears to be a porelike opening. These latter disconnected pieces continue all the way out to the extremities of the rays, and, with numerous smaller intervening ossicles, form together, as it were, the skeleton or framework of the long flexible rays. It is only, however, when an outer granular integument has been removed that this skeleton structure can be seen. In some parts of some of our specimens this outer granular covering remains, and is seen to be composed of numerous small, rounded, rather prominent ossicles, regularly arranged in qui[n]cunx, so as to give the surface a chagreenlike rough- ness. These ossicles were doubtless attached to, and secreted by, a soft dermal envelope, covering the whole surface, while the larger pieces within formed the frame, as it were, of the whole structure, and probably furnished points of attachment for the muscles that moved the rays.
‘‘None of our specimens show clearly the inner side or ambulacral furrows of the rays, nor the under side of the body—consequently we know nothing of the nature or position of the mouth or of the ambulacra. In several instances, however, we have seen the remains of one or more rows of small, short, longitudinally striated spines along the inner side of the arms.
50601°—Bull, 88—15——18
272 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
“‘The entire breadth of a mature individual, across between the extremities of the rays on opposite sides, if these rays were straight- ened out, would be about 5 to 6 inches.”
Formation and locality—This species occurs quite commonly in the famous crinid bed at Crawfordsville, Indiana, in the Keokuk formation of the Mississippic. Specimens are in several American museums; two are at Yale University, others in the United States National Museum.
Cat. No. 59392, U.S.N.M.
ONYCHASTER ASPER Miller.
Onychaster asper Mituer, Seventeenth Rep. Geol. Surv. Indiana, 1892, p. 684, pl. 12, figs. 3-5; advance extras, 1891, p. 74, pl. 12, figs. 3-5.—Mirusr, N. Amer. Geol. Pal., App. 1, 1892, p. 680, fig. 1240; App. 2, 1897, p. 749, fig. 1366.—Keyes, Missouri Geol. Surv., vol. 4, 1894, p. 181.
Original description.—‘ Dorsal side covered with an integument of small plates and numerous short spines. Central disk rather large, circular, convex, inflated from the point of contact with the arms. The outer integument covers the whole surface of the central disk, leaving no orifice exposed. Where the outer integument is worn off the disk is composed of rather large, polygonal spine bearing plates. The spines do not arise from the center of the plates, but laterally from little pits or sockets at the sutures. These sockets give the plates a somewhat sculptured appearance. The spines have a bulb at the base and taper to an obtuse point above.
‘‘The arms are long, rounded on the dorsal side, and very flexible. Figure 4 shows the arms abruptly folded from the middle over the ventral part, while figures 3 and 5 have the arms folded like the claws of a bird grasping some small object. There is a row of spines on each side of the arm furrows.
‘“This species is so different from the type that the generic reference is very doubtful.”
Formation and locality—-In the Keokuk formation of the Missis- sippic, at Boonville, Missouri. The specimens are said to be in the Miller and F. A. Sampson collections.
ONYCHASTER BARRISI (Hall).
Protaster ? burrisi Haut, Desc. N. Sp. Crinoidea, 1861, p. 18. Onychaster ? barrisi Merk and WortueEn, Proc. Acad. Nat. Sci. Philadelphia, vol. 21, 1869, p. 83; Geol. Surv. Illinois, vol. 5, 1873, p. 476, pl. 10, figs. la—-Id. Hall’s original description —“ A fragment of an Asterias, among the Burlington fossils, presents, in the rays and in the oral plates, some characters in common with Protaster; but I can discover no evidence of a central disk. The fragment preserves the center of the lower side and parts of four rays. All that remain of the rays are two distinct ranges of plates, which, near the base, are separated by a
REVISION OF PALEOZOIC STELLEROIDEA. 273
wide groove, but farther on appear to come in contact on their inner margins. These plates consist of joints closely articulated together, with a longitudinal foramen: their lower sides are marked lengthwise by a comparatively wide but not deep groove. The body of the plate has, on each side, a lateral arching process which is jointed at the two extremities, and separated in the center by a pore-like perfo- ration. There are ten oral plates, two from each division of the ray: these plates are expanded vertically; their extreme points have the inner edges slightly curving; the lower external faces are slightly indented, or crenulate; the surface of attachment is wide and strong, and constricted at the base by a distinct groove, beyond which it again expands.
“This form, if really without a disk, differs essentially from Prot- aster; and there are also other differences, which may make it necessary to constitute a distinct genus when better specimens shall be obtained.”
Formation and locality.—In the Burlington limestone at Burlington, Iowa. There are three specimens of this species in the Wachsmuth collection (Nos. 10, 11, and 12) at Harvard University.
ONYCHASTER CONFRAGOSUS Miller.
Onychaster confragosus MrttER, Seventeenth Rep. Geol. Surv. Indiana, 1892, p. 684, pl. 12, figs. 6, 7; advance extras, 1891, p. 74, pl. 12, figs. 6, 7.
Original description.—“ This species is so different from the one .ast described [O. asper], and also from the type of this genus, that it may not be congeneric with either of them. I have no doubt that it belongs to the same family. I have seen only the dorsal side of tho disk and the dorsal and lateral sides of the rays. There is no such integument of small plates covering the dorsal side as belongs to O. asper, but the surface is covered with short spines.
“The central part of the disk is somewhat injured in our specimens, and its character can not be definitely determined. It is surrounded by large, centrally convex, six-rayed plates. These rays seem to be the elevated ridges that separate the sockets for the insertion of the spines. Outside of this circle of ten six-rayed plates, there is a circle of quadrilateral plates more or less sculptured by the sockets for the spines, and here the radials may be said to commence. The dorsal side of each ray consists of three series of plates, and there is one series upon each side, or five series in an arm. ‘The first plates are connected laterally by smaller ones, in the angular depressions, between the commencement of the rays, which form part of the disk: All of the radial plates are more or less sculptured by the depressions for the insertion of the spines.. The spines are longer than the diam- eter of a plate, bulbous at the lower end, and taper to an obtuse point. The arms are long, round on the dorsal side, flexible and capable of being rolled up on the ventral side or being twisted laterally. No
274 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
such ovarian pores piercing the plates of the disk, as described and illustrated in O. flezilis, have been discovered.”
Formation and locality—In the Keokuk formation, at Boonville, Missouri. ‘Fhe cotypes are said to be in the Miller collection.
ONYCHASTER DEMISSUS Miller. Onychaster demissus MILLER, Seventeenth Rep. Geol. Surv. Indiana, 1892, p. 685, pl. 12, figs. 8-10; advance extras, 1891, p. 75, pl. 12, figs. 8-10; N. Amer. Geol. Pal., App. 1, 1892, p. 680, fig. 1241.
Original description. — This species hangs its arms down and folds them like the claws of a bird grasping some small object, and in these respects is more like O. flexils than cither of the preceding species. The central disk is slightly concave, subpentagonal in outline, and the rays drop down at right angles to the circumference of the disk.
“In the center of the disk there is a low, subcircular elevation, in which I have been unable to find any sutures, or to determine whether or not there is an opening of any kind; it appears to consist of a single plate. It is surrounded by aseries of ten plates that form the sub- pentagonal rim of the central disk. These plates are large, very convex, radiately sculptured, and bent down in the direction of the radial series as well as curving in to unite with the central plate. The sculpturing is due to the sockets for the insertion of the rays. The radial series commence from this circle of plates. The rays are angular on the dorsal side or obtusely rounded. The dorsal side of each ray consists of three series of plates, and there is one series on each side, or five series in an arm. ‘The first two plates in each ray are connected laterally by smaller ones, which form part of the disk, in the angular depressions, between the commencement of the rays. All of the radial plates are more or less sculptured or pitted by the depressions for the insertion of the spines.
“The arms are longer, more angular, and have rather smaller spines than either of the preceding species. J have been unable to detect any ovarian pores, but spine sockets very much resembling pores are indicated in figure 8, but they occur in the sutures and are readily distinguished from pores that pierce the plates.”
Formation and locality ——In the Keokuk formation, at Boonville, Missouri. The three cotypes are said to be in the Miller collection. There are two good specimens (No. 10994) in the Gurley collection at the University of Chicago, and another specimen, from Crawfords- ville, Indiana, in Yale University.
FORMS WHOSE RELATIONSHIPS ARE UNKNOWN. CRIBELLITES CARBONARIUS Tate. Cribellites carbonarius TaTE, Rept. Brit. Assoc. Adv. Sci., for 1863, 1864, Notices and abstracts, p. 88.
Original description.—‘‘This Asteroid, the first recorded from the
Mountain Limestone, is an impression of the upper surface, in a
REVISION OF PALEOZOIC STELLEROIDEA. y ALAS
fine-grained micaceous sandstone. It is named Cribellites carbo- narius; and the following characters are observable: Rays five, rounded, lanceolate, five times as long as the disk, ridged in the center, covered with longitudinal rows of reticulating tubercles; disk small and tuberculated. The disk is only 0.3 of an inch in diameter, while the rays are 1.5 inches in length. A circular impression in the disk may be the impression of the Madreporiform nucleus. In the form of this Asteroid, and in the characters observable, it is similar to Cribella rosea, Miller; but the rays are proportionally longer, the disk smaller, and the tubercles much nearer to each other than in the recent analogue. The sandstone from which the fossil Sea-star was obtained lies 20 feet above the Shilbottle coal, and about 600 feet below the base of the millstone grit, being in the upper part of the Mountain Limestone formation, which, in Northumberland, is about 3,000 feet in thickness. In this sandstone there also occur Strophomena crenistria and the remains of carboniferous plants.”
Order OPHIOCISTIA Sollas.
Ophiocistia Sottas, Quart. Journ. Geol. Soc. London, vol. 55, 1899, pp. 692, 700.— Sorntas and Sounas, Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, pp. 214, 222.
An anomalous order of free Echinoderma.
‘The Ophiocistia are Ophiuroidea with five paired series of append- ages, proceeding from the ventral surface of a plated test; and in which vertebral ossicles are absent or insignificant” (p. 700).
Contains but one family, the Eucladiidee.
Remarks.—That Eucladia and Euthemon, the genera belonging to this order, are ophiurids is said to be apparent from the following: “The absence of any openings on the dorsal surface, and of any indi- cation of an anus, the ventral position of the madreporite, and the sharp distinction of the arms from the test.” On the other hand, they differ from all known ophiurids in several important particu- lars:
“The structure and disposition of the arms is unlike anything known among either the Ophiure or the Euryale, and finds no parallel among any group of fossil Opniuroidea. If we consider the disposition of the arms first, we find as a constant character among the rest of the Ophiuroidea the extension of five of these appendages over the ventral surface of the disk as far as the buccal aperture; the vertebral ossicles of the arms are also serially represented in the buccal armature. In the Euciadiide also the arms are given off from the ventral surface of the test, and the first pair have their origin in the outer distal angle of the jaws; if, however, we are to regard the serial arms of Eucladiide as the free extremities of lateral
276 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
branches given off in pairs from a median hypothetical arm, then we must admit that the branching takes place within the test to an extent otherwise unknown within the class. If we turn next to the structure of the arms, we find no less striking peculiarities. No decisive evidence exists to prove that vertebral ossicles are present, but if they are they must be out of all proportion small compared with the lumen of the arm. Since the cavity of the arm is almost entirely unoccupied by skeletal structures, the question naturally arises as to the nature of the soft parts which it contained. The distal arms are so large that they might well have afforded room for extensions of the digestive viscera from the test. The absence of visible aper- tures in the arms is another very puzzling feature, and one ts almost tempted to inquire whether the paired appendages are to be compared with arms at all.
“The nature of the buccal armature is very different from that of any other Ophiuroid, though there is a certain amount of corre- spondence in the paired structure of its five pieces. The absence of any opening that could be taken for bursal apertures is noteworthy.”
Family EUCLADIID Gregory.
Eucladiide Grecory, Proc. Zool. Soc. London for 1896, 1897, p. 1040.—Soxzas, Quart. Journ. Geol. Soc. London, vol. 55, 1899, p. 692.—Srirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, p. 204.—Scu6npvorr, Jahrb, nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 236.
Contains the genera:
Eucladia Woodward. Euthemon Sollas.
Genus EUCLADIA Woodward.
Plates 37, 38.
Eucladia johnsoni H. Woopwarp, Geol. Mag., vol. 6, 1869, p. 241, pl. 8.—Zrrret, Handb. Pal., vol. 1, 1879, p. 443.—Sriirrz, Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, p. 30.—Greaory, Proc. Zool. Soc. London for 1896, 1897, p. 1040, fig. 6 on p. 1041.—Sotzas, Quart. Journ. Geol. Soc. Lon- don, vol. 55, 1899, p. 692.—Stiirrz, Verh. naturh. Ver. preuss. Rhein1., etc., vol. 56, 1900, p. 183.—ScH6Nnporr, Jahrb. nassauisch. Ver. Naturk., Wies- baden, vol. 62, 1909, p. 47; vol. 63, 1910, p. 240.—Soxias and Sox.as, Philos. Trans, Roy. Soc. London, ser. B, vol. 202, 1912, pp. 214, 222.—SpENcER, Mon. Brit. Pal. Asterozoa, pt. 1 (Paleeontogr. Soc. for 1913), 1914, p. 50.
This genus has seven pairs of arms in each radius, or 36 in all. These are covered with finely scaly integument.
Genoholotype.—E. johnsont Woodward (citations as above), Lower Ludlow formation, at Sedgley, near Dudley, England. Other species are EF. woodwardi Sollas, also from the Lower Ludlow, at Leintwar- dine, England, and F. ? beecheri, new species, from the Lower Devonic Coeymans limestone, New York.
REVISION OF PALEOZOIC STELLEROIDEA. oT
EUCLADIA WOODWARDI Sollas. Plate 37, figs. 1, 2.
Eucladia woodwardi Souuas, Quart. Journ. Geol. Soc. London, vol. 55, 1899, p. 695, figs. 1 and 2 on p. 694.
Original description—Ten specimens ‘‘agree in presenting five paired series of appendages, proceeding from the ventral surface of the body, which now possesses a more or less oval outline. The specimens are all of nearly the same size, the central body measur- ing about 2 by 3 em., the longest arms 2.5 cm. in length, and about 3 mm. in breadth where broadest. Not more than four, possibly only three, pairs of arms can be traced in connection with each radius, but an additional pair may have existed close to the buccal armature, and have since become crushed out of-recognition.
“The dorsal surface [fig. 1]—This is completely covered by nu- merous rounded polygonal or irregular scales, about 0.2 mm. thick and not exceeding 5 mm. in diameter; their surface is richly granu- lated. They are not arranged according to any discoverable law, though there may be a tendency to run parallel with the ambitus. In their present state they overlap each other to such an extent that one plate may be half concealed by another; no doubt they were imbricated during life, but the excessive overlap now presented is probably due in part to crushing. The direction of the imbrica- tion is upward, that is, in the direction opposite to that of tiles on a roof, and thus resembles the imbrication of the dorsal surface of a recent Ophiuroid. The plates are all of the same nature, and there are no openings on the dorsal surface.
‘The ventral surface [fig. 2)—In the center the powerful buccal armature is a very conspicuous object. It consists of five pairs of strong plates or ossicles, preciscly similar in their form and arrangement to those of Hucladia johnson. Around the armature are numerous small plates, irregularly disposed; from their form and size these may be regarded as elements of the test, though they may possibly include remains of crushed arms. If, as judging from analogy we might suppose, minute arms proceeded from the outer angles of the jaws, they have since disappeared.
‘Outside the irregularly scattered small plates larger ones are seen arranged; along the five radii these are escutcheon-shaped, imbricated, and form a single series of three. Distally, each plate is produced into three processes, a single median and two lateral; the angle formed by the side of the plate and each lateral process is rounded and thickened to form one side of a circular aperture for the passage or insertion of the arm, and the other half of the aperture is completed by the thickened margin of a similarly exca-
278 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
vated adjacent or adradial plate. The adradial plates form a pair, which meet in the interradius. The arrangement is similar to that which occurs in the genus Huthemon, to be next described; in the latter, however, the plates are not overlapping, but tesselated. The overlapping of the plates is less on the ventral than on the dorsal side, a difference which is probably due to the less amount of displacement suffered by the ventral plates; and this, again, is explicable on the assumption that the ventral surface was flatter than the dorsal.
“The arms.—The arms of this species do not exhibit that marked increase in size, as their position in the series becomes more distal, which is characteristic of Hucladia johnson. Their average length is 25mm. Near their tapering extremities the arms present on both dorsal and ventral surface three plates, two of which are lateral and one median, recalling the characteristic plating of an Ophiuroid arm; but nearer the origin the number of conspicuous plates on either surface is increased to four or even more, and smaller supple- mental plates are inserted between them in a manner precisely similar to that already described in the case of Eucladia johnson. The larger plates, swollen at first and becoming mucronate finally, are produced into a short awn-like termination.
‘‘A search, which proved unsuccessful, was made for some trace of vertebral ossicles; had these structures been present originally, they must either have been very small or some traces would still be discernible. In Lapworthura, which occurs in the same rocks, the vertebral ossicles are the most obvious elements in the brachial skeleton.
“The distinction of Hucladia woodward: from E. johnsoni rests on the smaller number of arms possessed by the former and the closer approach of these to equality in dimensions. The speci- men selected as the ‘type’ is exhibited in the Oxford University Museum, and bears a label stating where its description may be found.”
Formation and locality—tIn the Lower Ludlow, Leintwardine, England.
EUCLADIA (?) BEECHERI, new species.
Plate 38, fig. 1.
As this problematic fossil is of considerable interest, it is thought best to make it known in this work, even though the preservation is not good. The general characters are easily seen in the specimen, however, and much better than can be shown by photography, but in detail very little can be made out. The fossil lies in a dense dark limestone beneath the surface of a parting between two beds
REVISION OF PALEOZOIC STELLEROIDEA. 279
of stone. Originally but a few of the arms showed, and it was at once seen by the late Professor Beecher that he had found some- thing very different from a crinid. He bestowed a great deal of skill and labor on the fossil later on, bringing it out to its present relief, and in this condition it has remained since 1901, the year of its collection. It seemed to both Professor Beecher and the writer that it was an early form of branching or basket star, recalling the living Astrophyton. Recently, since reading the work of Sollas on FEucladia, it became clear that this view could not be maintained.
The specimen seemingly shows the ventral side.
The disk is large and distinctly pentagonal, and from its five cor- ners radiate the more or less coiled rays. Disk composed of de- cidedly thick plates, apparently closely adjoining, but their arrange- ment is too much disturbed and crystalline to make out. R= ? about 13 mm., 7=10.5 mm., R to edge of rays averaging 22 mm.
Rays apparently completely circular in outline and covered by an abundance of imbricating scales, of which there are about five across the diameter of a ray. The average diameter of the rays is between 1.5 and 2 mm. As the rays are crystalline the nature of the internal skeleton can not be made out further than that there are vertebre present. Each radius appears to have 4 pairs of arms, there being therefore 40 in all, but their situation in the disk and how they appear during growth cannot be made out. Three pairs are of the same size throughout, while the fourth pair, which lies upon the others, seems to be about half grown, and if there is no decided distortion of the disk plates, these appeared alternately, first on one side and then on the other. In Hucladia the 30 rays are practically all alike, but in ELuthemon the 20 arms are equally divided between full and half grown ones.
Formation and locality—From about the middle of the Coeymans limestone of the Helderbergian (Lower Devonic), at Jerusalem Hill, Litchfield, Herkimer County, New York. The holotype is in the Peabody Museum of Yale University.
Genus EUTHEMON Sollas.
Euthemon igerna Souias, Quart. Journ. Geol. Soc. London, vol. 55, 1899, p. 696, figs. 3 and 4 on p. 698.—So.tuas and Sou.as, Philos. Trans. Roy. Soc. Lon- don, ser. B, vol. 202, 1912, p. 222.
This genus is very similar to Hucladia, but differs at once in having but 4 arms in each radius, or 20 in all; 10 of these are more than twice as long (12 to 13 mm.) as the others (5 mm.).
Genoholotype and only species.—E. igerna Sollas, from the Wenlock limestone, Croft farm, Malvern, England.
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° = >
REVISION OF PALEOZOIC STELLEROIDEA. 283
Hat, J.—Continued.
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McCoy, F.
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18726. Descriptions of a few new species and one new genus of Silurian fossils from Ohio. Amer. Journ. Sci., ser. 3, vol. 4, pp. 274-281. (Protaster ? granuliferus, Palxaster incomptus, P. granulosus, P. speciosus, Alepidaster.)
1873. Descriptions of the invertebrate fossils of the Silurian and Devonian systems. Geol. Surv. Ohio, Pal., vol. 1, pp. 1-243, pls. 1-23, text figs.
MEEK, F. B., and WorrHen, A. W.
1861. Descriptions of new Carboniferous fossils from Illinois and other Western States, Proc. Acad. Nat. Sci., Philadelphia, for 1860, vol. 12, pp. 447-472. (Schenaster, S. fimbriatus.)
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284 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
MEEK, F. B., and Wortuen, A. W.—Continued.
1866a. Descriptions of invertebrates from the Carboniferous system. Geol. Surv. Illinois, vol. 2, pp. 145-411, pls. 14-32.
1866). Contributions to the paleontology of Illinois and other Western States. Proc. Acad. Nat. Sci., Philadelphia, for 1866, vol. 18, pp. 251-275. (Schenaster wachsmuthi.)
1868. Paleontology. Geol. Surv. Illinois, vol. 3, pp. 291-565, pls. 1-20, text figs.
(Onychaster, O. flexilis.)
1869a. Descriptions of new Crinoidea and Echinoidea from the Carboniferous rocksof the Western States, with a note on the genus Onychaster. Proc. Acad. Nat. Sci., Philadelphia, for 1869, vol. 21, pp. 67-83.
1869b. Descriptions of new Carboniferous fossils from the Western States. Proc. Acad. Nat. Sci., Philadelphia, for 1869, vol. 21, pp. 137-172. (Protaster ? gregarius. )
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Miter, S. A.
1878. Description of a new genus and eleven new species of fossils. Journ, Cin- cinnati Soc. Nat. Hist., vol. 1, pp. 100-108, pl.3. (Palzaster longibrachi- atus, P. clarket.)
1879. Description of twelve new fossil species, and remarks upon others. Journ. Cincinnati Soc. Nat. Hist., vol. 2, pp. 104-118, pls. 9,10. (Palzaster harrisi. )
1880a. Description of two new species from the Niagara group, and five from the Keokuk group. Journ. Cincinnati Soc. Nat. Hist., vol. 2, pp. 254-259, pl. 15. (Palexaster crawfordsvillensis.)
18806. Description of four new species of Silurian fossils, Journ. Cincinnati Soc. Nat. Hist., vol. 3, pp. 140-144, pl. 4. (Palzaster miamiensis.)
1880c. Description of four new species and a new variety of Silurian fossils, and remarks upon others. Journ. Cincinnati Soc. Nat. Hist., vol. 3, pp. 232-236, pl. 7. (Palzaster clarkana.)
1881. Description of some new and remarkable crinoids and other fossils of the Hudson River group. Journ. Cincinnati Soc. Nat. Hist., vol. 4, pp. 69-77, pl. 1. (Palxaster exculptus.)
1882a. Description of two new genera and eight new species of fossils from the Hudson River group, with remarks upon others. Journ. Cincinnati Soc. Nat. Hist., vol. 5, pp. 34-44, pls. 1.2. (Teniaster elegans.)
18826. Description of three new species, and remarks upon others. Journ, Cin- cinnati Soc. Nat. Hist., vol. 5, pp. 116-117, pl.5. (Protaster miamiensis.)
1884. Description of a beautiful star fish and other fossils. Journ. Cincinnati Soc. Nat. Hist., vol. 7, pp. 16-20, pl. 4. (Palxaster magnijicus.)
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Miter, S. A., and Dyrr, C. B.
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Mier, S. A., and Guripy, W. F. E.
1891. Description of some new genera and species of Echinodermata from the Coal Measures and Subcarboniferous rocks of Indiana, Missouri, and Iowa. Sixteenth Rept. Geol. Surv. Indiana, pp. 327-373, pls. 1-10; Advance extras, 1890. (Schenaster legrandensis, Aganaster.)
REVISION OF PALEOZOIC STELLEROIDEA. 285
Mitier, 8. A., and Guruey, W. F. E.—Continued.
1897. New species of erinoids, cephalopods, and other Paleozoic fossils. Bull.
Illinois State Mus. Nat. Hist., No. 12. (Palxaster wykoffi.) Mituer, J.
1855. In ZemerR and WrrTcen, Bemerkungen tiber die Petrefacten der iiltern devonischen Gebirge am Rheine, etc.; Verh. d. naturh. Ver. preuss. Rheinl., etc., vol. 12, pp. 1-28, pls. 1-9a. (Asterias rhenana.)
Murcurson, R. I.
1854. Siluria.
Nicnoitson, H. A., and ErnerimaGe, R., gr.
1880. A monograph of the Silurian fossils of the Girvan District in Ayrshire, fase. 3. (Tetraster, T. wyville-thomsoni.)
D’Orsteny, A. D. 1849. Prodrome de Paléontologie, vol. 1. (Colaster americanus.) Parks, W. A.
1908. Notes on the ophiuran genus, Protaster, with description of a new species. Trans. Canadian Inst., vol. 8, pp. 363-372, 1 pl. (Gives summary of history of genus. P. whiteavesianus.)
QuenstepT, F. A. 1876. Petrefactenkunde Deutschlands, vol. 4, Asteriden und Encriniden. Raymonp, P. E.
1912a. On two new Paleozoic starfish (one of them found near Ottawa), and a new crinoid. Ottawa Naturalist, vol. 26, pp. 77-81, pl. 5, 2 text figs. (Palzaster ? wilsoni, Schenaster ? montanus.)
19126. On the nature of the so-called ‘‘covering plates” in Protopaleeaster narra-
wayi. Ottawa Naturalist, vol. 26, pp. 105-108, pl. 6. RINGUEBERG, E. N. S.
1886. New genera and species of fossils from the Niagara shales. Bull. Buffalo Soc. Nat. Sci., vol. 5, pp. 5-22, pls. 1,2. (Squamaster, S. echinatus, Protaster stellifer, Eugaster concinnus.)
Roemer, F.
1863. Neue Asteriden und Crinoiden aus devonischem Dachschiefer von Bunden- bach bei Birkenfeld. Palzeontographica, vol. 9, pp. 143-152, pls. 23— 29. (Aspidosoma tischbeinianum, Asterias asperula, A. spinosissima, Helianthaster, H. rhenanus.)
RUEDEMANN, R.
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No. 162. (Teniaster schoharix.) Sarer, J. W.
1857. On some new Paleeozoic star-fishes. Ann. Mag. Nat. Hist., ser. 2, vol. 20, pp. 821-334, pl. 9. (Palxocoma, P. marstoni, I. colvini, P. cygnipes, Bdellacoma, B. vermiformis, Rhopalocoma, R. pyrotechnica, Palxaster asperrimus, P. coronella, Palasterina, Protaster miltoni, P. leptosoma.)
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1866. On the fossils of North Wales. Mem. Geol. Surv. Great Britain, vol. 3, App., pp. 240-381, pls. 1-28. (Palxaster imbricatus.)
Satter, J. W., and Sowrrsy, J. de C.
1845. In Sepawicx, On the Older Paleozoic (Protozoic) rocks of North Wales. Quart. Journ. Geol. Soc., London, vol. 1, pp. 5-22. (Ophiura salteri and Asterias primzva listed in table, without description.)
SANDBERGER, G., and SANDBERGER, I’.
1850-]856. Die Versteinerungen des rheinischen Schichtensystems in Nassau.
(Celaster, C. latiscutatus.)
286 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Scoénvorr, F. 1907a. Ueber einen fossilen Seestern Spanister latiscutatus Sandb. spec. aus dem Naturhistorischen Museum zu Wiesbaden. Jahrb. nassauisch. Ver. f. Naturk., Wiesbaden, vol. 60, pp. 170-176, 3 text figs. (Spaniaster.) 1907b. Ueber Archeeasterias rhenana Joh. Miiller und die Porenstellung palio- zoischer Seesterne. Centralb. f. Mineral., etc., pp. 741-750, 6 text figs. 1909a. Paliiozoische Seesterne Deutschlands. JI. Die echten Asteriden der rheinischen Grauwacke. Paleontographica, vol. 56, pp. 37-112, text figs., pls. 7-11. (Agalmaster, A. grandis, A. intermedius, A. miellensis, Rhenaster, R. schwerdi, Trimeraster, T. parvulus, Eifelaster, E. foll- manm, Xenaster dispar, X. elegans.) 19096. Die Asteriden des russischen Karbon. Paleeontographica, vol. 56, pp. 323-338, text fig., pls. 23, 24. : 1909c. Die fossilen Seesterne Nassaus. Jahrb. nassauisch. Ver. f. Naturk., Wiesbaden, vol. 62, pp. 7-46, text figs., pls. 2-5. (Discusses skeletal structure of asterids; Miomaster, M. drevermanni.) 19097. Organization und Aufbau der Armwirbel von Onychaster. Jahrb. nassau- isch. Ver. f. Naturk., Wiesbaden, vol. 62, pp. 47-63, pl. 6. 1910a. Ueber einige ‘“‘Ophiuriden und Asteriden” des englischen Silur und ihre Bedeutung fiir die Systematik paliiozoischer Seesterne. Jahrb. nassau- isch. Ver. f. Naturk., Wiesbaden, vol. 63, pp. 206-256, text figs. (Im- portant for classification. ) 1910b. Paliozoische Seesterne Deutschlands. II. Die Aspidosomatiden des deutschen Unterdevon. Paleontographica, vol. 57, pp. 1-63, pls. 1-3. (Discusses structure and systematics of group in much detail. Erects a new order, Auluroidea. Aspidosoma goldfusst, A. roemeri, A. eifelense.)
1910c. Aspidosoma schmidti nov. spec. Der erste Seestern aus den Siegener Schichten. Jahrb. k. preuss. geol. Landesanst. und Bergakad., Berlin, vol. 29, 1908, pt. 1, pp. 698-708, 1 pl.
1913a. Palaeaster eucharis Hall aus dem nordamerikanischen Devon. Jahrb.
nassauisch. Ver. f. Naturk., Wiesbaden, vol. 66, pp. 87-96, text figs. tL, 2,.pls 37 figs: 152: 1913b. Ueber Onychaster, einen Schlangenstern aus dem Karbon. Jahrb. nas- sauisch. Ver. f. Naturk., Wiesbaden, vol. 66, pp. 97-116, text figs. 1, 2, pl. 3, figs. 3-12. ScuucHErt, C. 1914. Fossilium Catalogus, I : Animalia, pars 3, Stelleroidea palaeozoica. SIMONOVITSCH, 8.
1871. Ueber einige Asterioiden der rheinischen Grauwacke. Sitzb. d. mat.- naturw. Classe d. k. Akad. d. Wiss., Wien, vol. 64, Abt. 1., pp. 77-122, pls. 14. (Xenaster, X. margaritatus, X. simplex, Asterias acuminatus, Aspidosoma petaloides.)
Souias, I. B. J.
1913. On Onychaster, a Carboniferous brittle-star. Philos. Trans. Roy. Soc.
London, ser. B, vol. 204, pp. 51-62, text figs. 1-5, pls. 8, 9. Souzas, W. J.
1899. Fossils in the University Museum, Oxford: I. On Silurian Echinoidea and Ophiuroidea. Quart. Journ. Geol. Soc., London, vol. 55, pp. 692-715, text figs. (Erects new order, Ophiocistia. Hucladia woodwardi, Euthe- mon, E. igerna.)
Souzas, W. J., and Sottas, I. B. J.
1912. Lapworthura: a typical brittle-star of the Silurian age. Philos. Trans. Roy. Soc. London, ser. B, vol. 202, pp. 213-232, text figs. 1-5, pls. 9, 10. (Rhodostoma, Protaster groom.)
REVISION OF PALEOZOIC STELLEROIDEA. 287
SPENCER, J. W.
1884. Niagara fossils, Pt. 3. Bull. Mus. Univ. State Missouri, No. 1, pp. 52-61,
pls. 7,8. (Palzxaster granti.) SPENCER, W. K.
1914. A monograph of the British Paleeozoic Asterozoa. Pt.1. Paleeontogr. Soc. for 1913, pp. 1-56, text figs. 1-31, pl. 1. (Koactis, E. simplex, Uranaster elize, Aspidosoma grayx, Lapworthura sollasi.)
STscHUROWSKY. 1874. Nachr. d. Moskauer Gesell. d. Liebhaber d. Naturges. (Asterias montanus.) Not seen. Sturtz, B.
1886a. Ueber paliiozoische Seesterne. N. Jahrb. f. Mineral., etc., vol. 2, pp. 142-154. (Hallaster.)
1886). Beitrag zur Kenntniss paliozoischer Seesterne. Palzeontographica, vol. 32, pp. 75-98, pls.8-14. (Ophiurella, O. primigenia, Roemeraster, R. asperula, Astropecten schliiteri, Eoluidia, E. decheni, Protasteracanthion, P. pri- mus, Furcaster, F. palxozoicus, Bundenbachia, B. beneckei, B. grandis, Palastropecten, P. zitteli, Loriolaster, L. mirabilis, Palasteriscus, P. devonicus.)
1890. Neuer Beitrag zur Kenntniss paliozoischer Seesterne. Palseontographica, vol. 36, pp. 203-247, pls. 26-31. (Echinasterella, E. sladeni, Cheiropter- aster, C. giganteus, Medusaster, M. rhenanus, Palxostella, P. solida, Ophiurina, O. lymani, Palxophiura, P. simplex, Palasterina follmanni. Describes additional material of forms dealt with in 1886, revises other species, discusses structure, systematics, habits, etc., of Paleozoic ophiurids and asterids.)
1893. Ueber versteinerte und lebende Seesterne. Verh. naturh. Ver. preuss. Rheinl., etc., vol. 50, pp. 1-92, pl. 1. (Salteraster, Ophiura rhenana, Palexnectria, P. devonica.)
1900. Ein weiterer Beitrag zur Kenntniss paliiozoischer Asteroiden. Verh. naturh. Ver. preuss. Rheinl., etc., vol. 56, pp. 176-240, pls. 24. (Reviews Gregory’s work of 1896 and gives classification of Ophiuroidea with definition of families. Hisingeraster, Trentonaster, Hudsonaster, Pseudo- palasterina, Eophiurites, Palexophiomyxa, Palxospondylus, Palzosolaster, P. gregoryi, Echinasterias, E. spinosus, Echinodiscus, E. multidactylus, Echinostella, E. traquairi, Jaekelaster, J. petaliformis.)
THORENT.
1838. Mémoire sur la constitution géologique de la partie nord du Departément de l’Aisne. Mem. Soc. géol. de France, vol. 3, pp. 239-260, pl. 22. (Asterias constellata.)
TRAUTSCHOLD, H.
1879. Die Kalkbriiche von Mjatschkowa, Theil 3. Mém. Soc. imp. Nat. Moscou,
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1835. Description of a new species of fossil Asterias (Asterias antiqua). Trans.
Geol. Soc. Pennsylvania, vol. 1, pp. 232-235. Urrica, E. O.
1878. Descriptions of some new species of fossils from the Cincinnati group; Journ. Cincinnati Soc. Nat. Hist., vol. 1, pp. 92-100, pl. 4. (Protasterina, P. fimbriata.)
1879. Descriptions of new genera and species of fossils from the Lower Silurian about Cincinnati. Journ. Cincinnati Soc. Nat. Hist., vol. 2, pp. 8-30, pl. 7. (Palxaster finei.)
50601°—Bull, 88—15 19
288 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
VERRILL, A. E.
1914. Monograph of the shallow-water starfishes of the North Pacific coast from the Arctic Ocean to California. Smithsonian Institution, Harriman Alaska ser., vol. 14.
Woopwarp, H.
1869. On Eucladia, a new genus of Ophiuride, from the Upper Silurian, Dudley. Geol. Mag., vol. 6, pp. 241-245, pl. 8. (Hucladia, E. johnsoni.)
1874. Description of a new species of starfish from the Devonian of Great Ingle- bourne, Harberton, South Devon. Geol. Mag., dec. 2, vol. 1, pp. 6-10, 96, 238, 432. (Helianthaster filiciformis.)
WorrHen, A. W., and Minter, S. A.
1883. Descriptions of new Carboniferous Echinoderms. Geol. Surv. Illinois, vol. 7, pp. 327-331, pl. 31. (Compsaster, C. formosus, Cholaster, C. pe- culiaris, Tremataster, T. difficilis.)
Wraicnt, T.
1862. A monograph on the British fossil Echinodermata from the Oolitic forma- tions, vol. 2, pt. 1. Paleontogr. Soc. for 1861. (Contains a diagnosis of nine Paleozoic genera with species.)
1873. On a new genus of Silurian Asteriadz. Quart. Journ. Geol. Soc., London, vol. 29, p. 421. (Trichotaster, T. plumiformis.)
ZirrEL, K. von. 1879. Handbuch der Paliontologie, vol. 1.
EXPLANATION OF PLATES. PuatTe 1.
Fic. 1.—Hudsonaster narrawayt (Hudson) (also see plates 2 and 4).
A greatly enlarged photograph of the genoholotype of Protopalzaster narrawayt Hudson. The inner ventral side of the specimen is here seen with all of the dorsal skeleton weathered away except one of the basal supramarginalia. Note the well-preserved oral armature and in places the ambulacralia. The latter are the ‘‘covering plates”? of Hudson.
Photograph by Prof. George H. Hudson.
Middle Ordovicic (Black River). Ottawa, Canada.
Collection of Mr. J. E. Narraway.
PLATE 2.
Fic. 1.—Hudsonaster narrawayi (Hudson) (also see plates 1 and 4). A photograph x 6 of the actinal side. Note the five long spines (tori) of the oral armature. Middle Ordovicic (Black River). Kirkfield, Ontario, Canada. Collection of Peabody Museum, Yale University. Fic. 2.—Hudsonaster matutinus (Hall) (also see plates 3 and 5). A photograph X 3 of three specimens showing the actinal area as preserved on a piece of black limestone. Middle Ordovicie (Trenton). Rathbone Brook, near Newport, Her- kimer County, New York. Collection of Museum of Comparative Zodlogy, Harvard University (No. 26).
PLATE 8.
Fia. 1.—Hudsonaster rugosus (Billings). A photograph X 2 of the abactinal area of a cotype. Upper Ordovicic (Richmondian). Charleton Point, Anticosti Island, Gulf of St. Lawrence, Canada. Collection of the Geological Survey of Canada (No. 1999). Fic. 2.—Hudsonaster matutinus (Hall) (also see plates 2 and 5). A retouched photograph 2 showing the abactinal side. Middle Ordovicic (Trenton). Trenton Falls, New York. Collection of the Museum of Comparative Zoélogy, Harvard University (No. 3). Fic. 3.—Hudsonaster bathert, new species. A diagram X 3 of the actinal side made from a wax squeeze by Bather, now in the United States National Museum (Cat. No. 60601). Upper Ordovicie. Thraive, Girvan, Scotland.
290 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
PLATE 4.
Fic. 1.—Hudsonaster narrawayt (Hudson) (also see plates 1 and 2).
A camera lucida drawing X 8 of the actinal side. The granules are drawn somewhat too strongly.
Middle Ordovicic (Black River). St. Paul, Minnesota.
Ulrich collection of the United States National Museum (Cat. No. 60602).
Fic. 2.—Hudsonaster milleri, new species.
A diagram, considerably enlarged, of an axillary area from the actinal side.
Middle Ordovicic (Trenton). Fayette County, Kentucky.
Collection of the State University of Kentucky.
Fic. 3.—Mesopaleaster (?) lanceolatus, new species.
Camera lucida drawing of one ray from the actinal area, X 2. The central furrow in the ambulacrum is decidedly V-shaped.
Upper Ordovicic (Utica). Near Rome, New York.
Collection of Peabody Museum, Yale University.
Fic. 4.—Australaster giganteus (Etheridge).
An axillary area and part of two rays somewhat reconstructed from the original figure. Natural size. Note the single very large axillary plate, the enlarging adambulacrals, and the diminishing inframarginals.
‘‘Permo-Carboniferous” (Lower Marine). Farley, Northumberland County, New South Wales.
Collection of the Mining and Geological Museum, Sydney.
PuLaTE 5.
Fries. 1 and 2.—Hudsonaster matutinus (Hall) (also see plates 2 and 3).
1. Camera lucida drawing x 3.5 of the actinal side of one of the speci- mens photographed on plate 2, fig. 2.
Middle Ordovicic (Trenton). Near Newport, New York.
Collection of Museum of Comparative Zodlogy, Harvard University (No. 26).
2. Camera lucida drawing X 4.5 of the abactinal area of a specimen in which the ossicles are somewhat displaced.
Middle Ordovicic (Trenton). Lachine, near Montreal, Canada.
Collection of the United States National Museum (Cat. No. 60603). Collected by W. R. Billings.
PLATE 6.
Fics. 1 and 2.—Hudsonaster incompius (Meek).
1. Camera lucida drawing X 4 of the actinal side.
Upper Ordovicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No, 40882).
2. Camera lucida drawing X 4 of the abactinal area in a well preserved specimen. The anal opening may have been in the first circle of small plates adjacent to the centro-dorsal piece and in the same interradius as the madreporite.
Upper Ordoyicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat, No. 40882).
REVISION OF PALEOZOIC STELLEROIDEA. 291
PLATE 7.
Fias. 1-4.—Palzaster niagarensis Hall.
1. Camera lucida drawing X 4 of the abactinal side in its present preservation. Holotype.
2. Abactinal side of the holotype restored, x 4. The drawing probably has too many accessory disk pieces.
3. Camera lucida drawing X 4 of the actinal side of one of the rays of the holotype. Since this drawing was made the rock in the ambulacral furrow has been dug away down to the ambulacral plates, which are small and deep-seated.
4. A few of the inframarginals and supramarginals from the abactinal side to show the smooth central areas surrounded by granular borders, x 4.
Siluric (Rochester shale). Lockport, New York.
Collection of Cornell University (No. 7331).
Fic. 5.— Mesopalexaster finei (Ulrich) (also see plate 9).
Camera lucida drawing X 16 of one of the rays. The ossicles are always more or less displaced in this species.
Upper Ordovicic (Eden shales). Cincinnati, Ohio.
Ulrich collection of the United States National Museum (Cat. No. 60604).
PLATE 8.
Frias. 1 and 2.— Mesopaleaster shafferi (Hall).
1. Camera lucida drawing X 8 of the abactinal side of a one-third adult-sized specimen. As the medial disk pieces are displaced in the individual, they are here drawn in in their probable natural arrangement all should be pointed like the central disk plate.
Upper Ordovicic (Maysvillian, Corryville member). Cincinnati, Ohio.
ee collection of the United States National Museum (Cat. No. 60605).
2. Camera lucida drawing X 3 of the actinal area of a mature indi- vidual.
Upper Ordovicic (Richmondian), Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 59391).
Fria. 3.—Miomaster drevermanni Schondorf. Actinal side as reconstructed by Schéndorf. Natural size. Lower Devonic (Upper Coblenzian). Miellen, Germany.
PLATE 9.
Fia. 1.— Mesopalexaster (?) parviusculus (Billings). Camera lucida drawing 5 of a gutta-percha squeeze of the holotype, actinal side. Siluric (Lower Arisaig). Arisaig, Nova Scotia. Original at McGill University; gutta-percha squeeze in United States National Museum (Cat. No. 60620). Fia. 2.— Mesopalexaster (?) cataractensis, new species. Photograph 3 of the well-preserved holotype. Silurie (Cataract formation). Hamilton, Ontario. Collection of the Hamilton Natural History Society. Fia. 3.— Mesopaleaster (?) granti (Spencer). Photograph 2 of a specimen showing the dorsal side. Siluric (Cataract formation). Hamilton, Ontario. Collection of Peabody Museum, Yale University.
292 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Fic. 4.—Mesopalxaster intermedius, new species. Photograph X 3 of the holotype. Between the two rays lies an arm of a crinid, giving the impression that this form has a large disk. Upper Ordovicic (Maysvillian). Cincinnati, Ohio. Collection of the University of Chicago (No. 9575). Fia. 5.—Mesopalzaster finei (Ulrich) (also see plate 7). Ulrich’s original figures. Fig. 5, one of the cotypes from the abactinal side X 2; fig. 5a, the madreporite & 6; fig. 5b, aray from the actinal side X 3. Upper Ordovicic (Eden). Cincinnati, Ohio. Ulrich collection of the United States National Museum (Cat. No. 60604). Fia. 6.—Mesopalexaster caractaci (Gregory) (also see plate 11). Retouched photograph X 3 of a wax squeeze by Bather, now in the United States National Museum (Cat. No. 60606). Actinal area. Ordovicic (Caradoc). Church Stretton, England.
Puate 10.
Fras. 1 and 2.—Mesopaleaster clarki (Clarke and Swartz). 1. Drawing of the actinal side of the holotype X 1.5.
2. Abactinal area X 1.5. Note the few accessory pieces in the angles between the radials.
Upper Devonic (Chemung). Near Oakland, Maryland. Collection of the Maryland Geological Survey.
PLATE ILI.
Fra. 1.— Mesopalwaster caractaci (Gregory) (also see plate 9). Retouched photograph x 3 of a wax squeeze by Bather, now in the United States National Museum (Cat. No. 60606). Abactinal area. Ordovicic (Caradoc). Church Stretton, England. Fia. 2.—Devonaster chemungensis, new species. Photograph of the natural mold of the actinal side of the holotype, natural size. Upper Devonic (Chemung). ‘‘Central Pennsylvania.” Collection of Columbia University (No. 6228G).
PLATE 12.
Fras. 1 and 2.—Spaniaster latiscutatus (Sandberger). 1. Abactinal side. 2. Actinal side. After Schéndorf. Lower Devonic. Germany. Fras. 3-5.—Devonaster eucharis (Hall). 3. Abactinal side, natural size. a, the madreporite. After Hall. 4. Actinal side, natural size. After Hall. The tiny ambulacral plates should have been drawn as opposite one another and not alternate. 5. Hall’s diagram (3a) of the actinal plate arrangement. The ambu- lacrals are incorrectly drawn, as their arrangement is opposite and not alternate. a, ambulacralia; aa, adambulacralia; m, inframarginalia; o, pairs of oral armature ossicles; p, podial openings, but drawn a little too large; tm, the single interbrachial axillaries. Middle Devonic (Hamilton). Near Hamilton, New York.
REVISION OF PALEOZOIC STELLEROIDEA. 293 PLATE 13.
Fras. 1 and 2.—Promopalzaster wilsont (Raymond). 1. Photograph X 1.5 of the holotype, showing the abactinal side. 2. One of the rays of the holotype X 3. Middle Ordovicic (Lowville). City View, Ottawa, Canada. Collection of Miss A. E. Wilson. Fia. 3.—Promopalxaster prenuntius, new species (also see plate 15). Photograph, natural size, of the actinal side of the holotype. Middle Ordovicic (Lower Trenton). Frankfort, Kentucky. Collection of the State University of Kentucky. Fia. 4.—Anorthaster miamiensis (Miller) (see also plate 20). Retouched photograph, natural size, of the actinal side of the holotype. Upper Ordovicic (Richmondian). Waynesville, Ohio. Harris collection of the United States National Museum (Cat. No. 40880). Fia. 5.-—Neopalzxaster crawfordsvillensis (Miller) (see also plate 23). Retouched photograph, natural size, of the holotype, showing the abac- tinal area. Mississippic (Keokuk). Crawfordsville, Indiana. Harris collection of the United States National Museum (Cat. No. 60607).
Pruate 14,
Fies. 1 and 2.—Promopalezaster speciosus (Meek)? Reproduction, natural size, of the original lithograph of ‘‘ Asterias pri- mordialis.’’ Probably the young of P. speciosus. Upper Ordovicic (Maysvillian). Cincinnati, Ohio. The specimen is now lost. Fies. 3 and 4.—Promopalzxaster speciosus (Meek) (also see plate 15). Photographs, natural size, of the abactinal and actinal sides of the holotype. Upper Ordovicie (Maysvillian). Cincinnati, Ohio. Dyer collection of the Museum of Comparative Zodlogy, Harvard University (No. 22).
PLATE 15.
Fias. 14.—Promopalxaster speciosus (Meek) (also see plate 14). 1. Camera lucida drawing X 4 of an interbrachial area. 2, Camera lucida drawing X 4 across a ray at about its mid-length. From the actinal side, showing the ambulacrals, podial openings, adambulacrals, inframarginals, and supramarginals. 3. Two adambulacral spines near oral region, x 7. 4. A part of the abactinal area of a ray near its mid-length, < 2.5. All drawn from the holotype. Upper Ordovicic (Maysvillian). Cincinnati, Ohio. Dyer collection of the Museum of Comparative Zodlogy, Harvard Uni- versity (No. 22). Fie. 5.—Promopaleaster prenuntius, new species (also see plate 13). Diagram of the actinal interbrachial plate arrangement,
294 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Fias. 6-8.—Promopaleaster bellulus, new species (also see plates 16 and 18).
6. Camera lucida drawing X 4 of an interbrachial area. The adambu- lacrals are in natural position, but the interbrachial axillaries and the inframarginals are somewhat displaced. Taken from the specimen on plate 16, fig. 1.
7. Camera lucida drawing X 7 of the abactinal area of a ray. The ossicles are all displaced, but originally they were united in a spicular and partially overlapping mesh.
8. Madreporite X 7.
Upper Ordovicic (Richmondian). Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40879).
Prate 16.
Fie. 1.—Promopalexaster bellulus, new species (also see plates 15 and 18). Retouched photograph, natural size, of the actinal side. The specimen is in limestone. Upper Ordovicie (Richmondian). Waynesville, Ohio. Harris collection of the United States National Museum (Cat. No. 40879). Fia. 2.—Promopaleaster spinulosus (Miller and Dyer) (also see plates 17 and 18). Retouched photograph, natural size, of the actinal side of the holotype of Palxaster longibrachiatus Miller. The well-preserved columns are the inframarginals, but in places some of the adambulacrals are also shown. Upper Ordovicic (Richmondian). Near Clarksville, Ohio. Harris collection of the United States National Museum (Cat. No. 40881).
PLATE 17.
Fias. 1 and 2.—Promopalxaster spinulosus (Miller and Dyer) (also see plates 16 and 18). Retouched photographs x 3 of the actinal and abactinal sides of the holotype. Upper Ordovicic (Richmondian). Probably near Waynesville, Ohio. Dyer collection of the Museum of Comparative Zodlogy, Harvard University (No. 16).
Puate 18.
Fias. 1-3.—Promopaleaster spinulosus (Miller and Dyer) (also see plates 16 and 17).
1. Camera lucida drawing X 2, somewhat restored, of the holotype of Palxaster longibrachiatus Miller.
2. Camera lucida drawing X 7 of the abactinal area of a ray near its base. Shows the large infra- and supramarginals and ambital pieces. Center of ray has spicular ossicles.
3. Madreporite X 7.
Upper Ordovicic (Richmondian). Near Clarksville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40881).
REVISION OF PALEOZOIC STELLEROIDEA. 295
Fies. 4 and 5.—Promopalzaster bellulus, new species (also see plates 15 and 16).
4. Adambulacralia and their spines, X 7. The ambulacrum lies to the left.
5. A few abactinal spines, x 7.
Upper Ordovicie (Richmondian). Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40879).
Fic. 6.—Promopalzaster wykoffi (Miller and Gurley) (also see plate 19).
Diagram X 3.5 of one of the interbrachial areas.
From the holotype.
Upper Ordovicic (Richmondian). Near Madison, Indiana.
Collection of the University of Chicago (No. 6066). Fig. 7.—Promopalxaster exculptus (Miller) (also see plate 20).
Adambulacral and ambulacral plates at about mid-length of a ray, x 4.
From the holotype.
Upper Ordovicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 60608).
Fie. 8.—Promopaleaster dyert (Meek) (also see plates 20 and 25).
Five inframarginal plates x 4. To show the articulations for the stout spines that lie on the right. Also note the smaller spines. The plate extensions to the left connect with the vertical ridges on the ambulacral plates.
From the holotype.
Upper Ordovicic (Maysvillian). Cincinnati, Ohio.
Dyer collection of the Museum of Comparative Zoélogy, Harvard Univer- sity (No. 13).
PuatTeE 19.
Fia. 1.—Trimeraster parvulus Schondorf. Reconstruction * 1.75 of the actinal side. After Schéndorf. Lower Devonic (Coblenzian). Near Rhens, Germany. Fie. 2.—Promopaleaster wykoffi (Miller and Gurley) (also see plate 18). Photograph X 2 of the holotype, showing the actinal side. One of the finest of Paleozoic specimens. Upper Ordovicie (Richmondian). Near Madison, Indiana. Collection of the University of Chicago (No. 6066).
PLATE 20.
Fie. 1.—Anorthaster miamiensis (Miller) (also see plate 13).
Camera lucida drawing X 5.5 of one of the interbrachial areas of the holotype. The only Paleozoic form known with the area wholly made up of adambulacrals.
Upper Ordovicic (Richmondian). Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40880).
Fia. 2.—Promopalzxaster exculptus (Miller) (also see plate 18).
Camera lucida drawing X 4 of an interbrachial area. Note the modified ambulacral plates in connection with the oral armature. Holotype.
Upper Ordovicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 60608).
296 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Fias. 3-6.—Promopalexaster dyeri (Meek) (also see plates 18 and 25).
3. One of the interbrachial areas with the ossicles displaced and the adjoining adambulacral plates with their spines, X 4.
4. Madreporite x 4. The rest of the plate is covered.
5. Two abactinal spines, X 7.
6. Five different abactinal ossicles, X 7.
All drawn from the holotype.
Upper Ordovicic (Maysvillian). Cincinnati, Ohio.
Dyer collection of the Museum of Comparative Zodlogy, Harvard Uni- versity (No. 18).
PLATE 21.
Fia. 1.—Promopalexaster magnificus (Miller) (also see plates 22 and 23).
Photograph, natural size, of the actinal side of one of the cotypes. This speci nen is probably the best preserved of Paleozoic starfishes and is one of the largest species.
Upper Ordovicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40883).
PLATE 22.
Fic. 1.—Promopaleaster magnificus (Miller) (also see plates 21 and 23). Abactinal side of the same specimen illustrated on plate 21.
PLATE 23.
Fras. 1-3.—Promopalxaster magnificus (Miller) (also see plates 21 and 22).
1. Camera lucida drawing X 3.5 of an interbrachial area. Additional tube-feet probably also came out at the junction of the forked crests.
2. Camera lucida drawing X 4 of the actinal area of one of the rays toward the distal ends. Large adambulacrals bound the rays distally, while the smaller pieces outside are the inframarginals.
3. A distal portion of the abactinal area, X 3.5.
All drawn from the cotypes.
Upper Ordovicic (Richmondian). Near Waynesville, Ohio.
Harris collection of the United States National Museum (Cat. No. 40883).
Fie. 4.—Neopalexaster crawfordsvillensis (Miller) (also see plate 13).
Camera lucida drawing X 4 of the abactinal area of the holotype. Ac- cessory disk pieces are drawn in; in the specimen they are all displaced. The madreporite should be more finely striate. In places the dorsal skeleton is lost, exposing the ambulacrals.
Mississippic (Keokuk). Crawfordsville, Indiana.
Harris collection of the United States National Museum (Cat. No. 60607).
Fias. 5-7.—Petraster speciosus (Miller and Dyer) (also see plates 26 and 27).
5. The ambulacral, adambulacral and inframarginals of a ray at its mid-length, < 4. Seen from the actinal side.
6. Inframarginal, accessory interbrachial, and adambulacral pieces, X 4. Seen from the dorsal side.
7, Ambulacral and adambulacrals, x 4. Seen from the dorsal area,
REVISION OF PALEOZOIC STELLEROIDEA. 297
PLATE 24.
Fias. 1-2.—Xenaster margaritatus Simonovitsch.
1. Reconstruction, somewhat enlarged, of the abactinal side. The structure of the medial portion of the disk is based upon Agalmaster miellensis. .
2. Reconstruction, somewhat enlarged, of the actinal area.
After Schéndorf.
Lower Devonic (Upper Coblenzian). Niederlahnstein, Germany.
PLATE 25.
Fie. 1.—Promogalzxaster dyeri (Meek) (also see plates 18 and 20). Retouched photograph, natural size, of the actinal side of the holotype. Upper Ordovicic (Maysvillian). Cincinnati, Ohio. Dyer collection, Museum of Comparative Zodlogy, Harvard University (No. 18). Fie. 2.—Lepidasterella babcocki, new species. Photograph X 1.5 of the holotype. A natural mold of the abactinal area in sandstone. Upper Devonic (Lower Chemung). Near Ithaca, New York. Collection of Mrs. G. W. Babcock.
PLATE 26.
Fic. 1.—Petraster speciosus (Miller and Dyer) (also see plates 23 and 27).
Retouched photograph, natural size, of the abactinal area of the holotype.
Upper Ordovicic (Richmondian). Near Winchester, Ohio.
Dyer collection of the Museum of Comparative Zoélogy, Harvard Uni- versity (No. 14).
Fie. 2.—Petraster (?) americanus (D’Orbigny).
Reproduction, natural size, of Meek’s original figure. The specimen is seen from the abactinal side, exposing, however, the inner surface of the actinal skeleton, which is deeply embedded in limestone.
Upper Ordovicic (Maysvillian). Cincinnati, Ohio.
Collection of the University of Chicago.
PLATE 27.
Fias. 1-4.—Petraster speciosus (Miller and Dyer) (also see plates 23 and 26). 1, Camera lucida drawing X 4 of the abactinal side of aray. Holotype The inframarginals border the animal, with the supramarginals imme-
diately inside of them. The radial column is readily distinguished along the center of the rays.
2. Camera lucida drawing x 6 of an interbrachial area in a young individual (Harris collection, Cat. No. 60609, U.S.N.M.). The inframar- marginals are above and the adambulacrals below to the right. The rest rest of the plates are accessory interbrachials.
3-4, Madreporite from the side and from the lower or under surface, X 8.
Fie. 5.—Petraster rigidus (Billings).
Outline tracing of the actinal skeleton from a photograph X 2 of the holotype.
Middle Ordovicic (Trenton). Ottawa, Canada.
Collection of the Geological Survey of Canada (No. 1401a).
298 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Fias. 6-8.—Urasterella grandis (Meek) (also see plates 28 and 30).
6. Camera lucida drawing X 8 of part of the abactinal area of a ray proxi. mally. Note how the ossicles are drawn out into nonarticulating blunt spines.
7. Camera lucida drawing X 4 of the actinal side about the mouth. The complete oral armature is preserved.
8. Madreporite in outline, X 7.
From specimens in the Harris collection of the United States National Museum (Cat. No. 40885).
PLATE 28.
Fias. 1 and 2.—Urasterella grandis (Meek) (also see plates 27 and 30). 1. Retouched photograph, natural size, of a large and folded specimen. Both ventral and dorsal areas are shown. 2. Retouched photograph, natural size, of an average individual seen from the actinal side. Upper Ordovicic (Richmondian). Near Waynesville, Ohio. Harris collection of the United States National Museum (Cat. No. 40885). Fics. 3 and 4.—Urasterella pulchella (Billings) (also see plate 30). 3. Photograph, natural size, of an electrotype, seen from the actinal side. Middle Ordovicic (Trenton). Hull, Ottawa, Canada. Original in collection of the Geological Survey of Canada; electrotype in United States National Museum (Cat. No. 60610). 4. Retouched photograph, natural size, of the abactinal area. Middle Ordovicic (Trenton). Trenton Falls, New York. Collection of the Museum of Comparative Zodlogy, Harvard University (No. 31). Fia. 5.—Urasterella girvanensis, new species. Reproduction X 2 of the original figure by Nicholson and Etheridge, somewhat altered. From a wax squeeze made by Bather, now in the United States National Museum (Cat. No. 60611). Upper Ordovicic. Thraive, Girvan, Scotland.
PLATE 29.
Fia. 1.—Urasterella ulrichi, new species (also see plate 30).
Retouched photograph, natural size, of the abactinal side of a cotype.
The three short blunt rays are interpreted as healed stumps.
Middle Ordovicic (Black River). Minneapolis, Minnesota.
Ulrich collection of the United States National Museum (Cat. No. 60612). Fig. 2.—Urasterella hualeyi (Billings).
Photograph X 2 of the holotype. Abactinal view.
Middle Ordovicic (about Chazy). Point Rich, Newfoundland.
Collection of the Geological Survey of Canada (No. 554.)
PLATE 30.
Fics. 14.—Urasterella grandis (Meek) (also see plates 27 and 28.)
1-2. Camera lucida drawing X 16 of the adambulacrals with their articu- lar spines and probable paxille.
3, Camera lucida drawing X 8 of the two columns of ambulacral plates a little displaced. The podial openings are situated laterally between the thinner ends of the ossicles.
4. Camera lucida drawing X 7 of the adambulacrals with their spines.
From specimens in the Harris collection of the United States National
Museum (Cat. No. 40885).
REVISION OF PALEOZOIC STELLEROIDEA. 299
Fia. 5.—Urasterella pulchella (Billings) (also see plate 28).
Camera lucida drawing X 8. The large plates to the left are the coin- shaped adambulacrals (some have tipped over and show their articular faces), next are the small elongate inframarginals, and outside of these are the spinose ambitals.
Fiaes. 6 and 7.— Urasterella ulrichi, new species (also see plate 29).
6. Camera lucida drawing X 4 of the abactinal side of a young individual. The medial ray plates should be more tumid than here represented. Note the primitive structure of the disk.
7. Camera lucida drawing 6 of the actinal side of a young indi- vidual. The outer dark margin is adhering rock, through which some of the abactinal ambital nonarticulating spines project. Note the phanerozonian interbrachial characters.
Middle Ordovicic (Black River). Minneapolis, Minnesota.
Ulrich collection of the United States National Museum (Cat.
No. 60612). : 4 LATE ‘
Fies. 1 and 2.—Compsaster formosus Worthen and Miller. 1. Actinal view, natural size, of the holotype. Reproduction of the original illustration. 2. Part of aray, X 2. After Worthen and Miller. Upper Mississippic (Chester). Okaw Bluffs, Ilinois. ‘‘Tllinois State collection of 1880, No. 2476.”’ Fic. 3.—Calliasterella mira (Trautschold). Reproduction, natural size, of Schéndortf’s reconstruction. Upper Carboniferous (Moscovian). Mjatschkowa, near Moscow, Russia.
PLATE 32. Fie. 1.—Stenaster saltert Billings. Retouched photograph X 3 of a cotype. Actinal view. Middle Ordovicic (Trenton). Belleville, Ontario, Canada. Collection of the Geological Survey of Canada. Fia. 2.—Schuchertia stellata (Billings) (also see plate 33). Photograph x 4 of the actinal side of the holotype. Middle Ordovicic (Trenton). Ottawa, Canada. Collection of the Geological Survey of Canada (No. 1399). Fig. 3.—Schuchertia laxata, new species (also see plate 33). Retouched photograph 2 of the holotype from the abactinal side. Upper Ordovicie (Richmondian). Waynesville, Ohio. Harris collection of the United States National Museum (Cat. No. 60613). Fias. 4and 6.—Schenaster (?) legrandensis Miller and Gurley. 4-5. Actinal and abactinal views, natural size. 6. Part of actinal side & 6.5. After Miller and Gurley. Lower Mississippic (Kinderhookian). Le Grand, Iowa. ?Gurley collection of the University of Chicago.
PLATE 33.
Fia. 1.—Schuchertia stellata (Billings) (also see plate 32). Camera lucida drawing xX 8 of the abactinal surface. Somewhat restored. Middle Ordovicic (Trenton). Near New Edinburgh, Canada. Collection of the Geological Survey of Canada. Fias. 2 and 3.—Schuchertia laxata, new species (also see plate 32). 2. Some of the outer ambital plates, all disjointed, x 8. 3. An interbrachial area and ambulacrum, X 4. Upper Ordovicic (Richmondian). Waynesville, Ohio. Harris collection of the United States National Museum (Cat. No. 60613).
300 BULLETIN 88, UNITED STATES NATIONAL MUSEUM.
Fig. 4.—Tetraster wyville-thomsoni Nicholson and Etheridge. Diagram X 4 of the actinal skeleton. From a wax squeeze by Bather, in the United States National Museum (Cat. No. 60614). Upper Ordovicic. Thraive, Girvan, Scotland. Fie. 5.—Schenaster (?) montanus Raymond. Reproduction X 2 of the original figure. Actinal side. Mississippic (Madison). Spring Canyon, near Alder, Montana. Collection of the Carnegie Museum. Fic. 6.—Schenaster (?) wachsmuthi Meek and Worthen. Reproduction, natural size, of the original figure. Actinal view. Lower Mississippic (Burlington). Burlington, Iowa. Collection of the Museum of Comparative Zodlogy, Harvard University (No. 7).
PLATE 34.
Fic. 1.—Palzosolaster (?) gyalum (Clarke). Actinal view of one of the cotypes, natural size, Upper Devonic (Portage). Ithaca, New York. Collection of Cornell University.
PLATE 35.
Frias. 14.—Schenaster fimbriatus Meek and Worthen. 1. View of the abactinal side, natural size, of one of the cotypes. 2. Enlarged view of one of the rays, showing the arrangement of the ossicles and the pores, as seen when the surface is ground down. 3. Actinal side of a ray, enlarged, showing only the adambulacrals. 4, Actinal side of another cotype, natural size. The original figures of plate 19, figs. 7a to 7d. Upper Mississippic (St. Louis). St, Clair County, Illinois. Fias. 5 and 6—Encrinaster petaloides (Simonovitsch). 5, Abactinal view, about X 2. 6. An arm from the actinal side, about X 2. After Schéndorf. Lower Devonic (Upper Coblenzian). Niederlahnstein, Germany.
PLATE 36.
Fie. 1.—Teniaster spinosus (Billings). Photograph X 2 showing the actinal side of one of the cotypes. Middle Ordovicic (Lower Trenton). Montmorency Falls, Quebec, Canada. Collection of the Geological Survey of Canada (No. 1404). Fics. 2.and 3.—Texniaster cylindricus (Billings). 2. Abactinal view X 2 of one of the cotypes. 3. Actinal view X 2 of another cotype. Both specimens are on the same slab. Middle Ordovicic (Trenton). Ottawa, Canada. Collection of the Geological Survey of Canada (No. 1405a). Fia. 4.—Alepidaster flecuosus (Miller and Dyer). An unpublished photograph X 3.5, made many years ago, of the holo- type of Protasterina fimbriaia Ulrich. Upper Ordovicie (Lower Edenian), Covington, Kentucky. Ulrich collection of the United States National Museum (Cat. No. 60615).
REVISION OF PALEOZOIC STELLEROIDEA. SUL
PLATE 37.
Fras, 1 and 2.—Eucladia woodwardi Sollas. Dorsal and ventral reconstructions 5/3 of this remarkable fossil. On it is based the order Ophiocistia Sollas. ‘“‘One arm, the most proximal of the radius on the lower right-hand corner, is omitted, so as to show the aperture from which it proceeds.’”’? After Sollas. Siluric (Lower Ludlow). Leintwardine, England.
PLATE 38.
Fia. 1.—Eucladia (?) beecheri, new species. Photograph Xx 2 of the holotype from the actinal side. The specimen itself is difficult to make out, hence the indistinctness of the photograph. Lower Devonic (Coeymans). Jerusalem Hill, Litchfield, Herkimer County, New York. Collection of Peabody Museum, Yale University.
U. S. NATIONAL MUSEUM BULLETIN 88 PL. 1
HUDSONASTER NARRAWAYI.
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1, HUDSONASTER RUGOSUS; 2, H. MATUTINUS; 3, H. BATHERI.
FOR EXPLANATION OF PLATE SEE PAGE 289.
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FOR EXPLANATION OF PLATE SEE PAGE 290.
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U. S. NATIONAL MUSEUM
HUDSONASTER INCOMPTUS.
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1, MESOPALZASTER CARACTACI; 2, DEVONASTER CHEMUNGENSIS.
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U. S. NATIONAL MUSEUM BULLETIN 88 PL. 13
1-3, PROMOPALAZASTER; 4, ANORTHASTER; 5, NEOPALAZASTER.
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1-4, PROMOPALAASTER SPECIOSUS; 5, P. PRENUNTIUS; 6-8, P. BELLULUS.
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1, TRIMERASTER PARVULUS; 2, PROMOPALAZZASTER WYKOFFI.
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1, DETAIL OF ANORTHASTER; 2-6, PROMOPALAZASTER.
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1-3, DETAIL OF PROMOPALZASTER; 4, NEOPALAZASTER; 5-7, PETRASTER.
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FOR EXPLANATION OF PLATE SEE PAGE 297.
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FOR EXPLANATION OF PLATE SEE PAGE 297,
BULLETIN 88 PL. 26
U. S. NATIONAL MUSEUM
1, PETRASTER SPECIOSUS; 2, P. (7?) AMERICANUS.
For EXPLANATION OF PLATE SEE PAGE 297.
27
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1-5, DETAIL OF PETRASTER; 6-8, URASTERELLA.
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URASTERELLA GRANDIS; 3, 4, U. PULCHELLA; 5, U. GIRVANENSIS.
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DETAIL OF URASTERELLA.
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For EXPLANATION OF PLATE SEE PAGES 298 AND
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1, COMPSASTER FORMOSUS; 2, CALLIASTERELLA MIRA.
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FOR EXPLANATION OF PLATE SEE PAGE 299,
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1-3, DETAIL OF SCHUCHERTIA; 4, TETRASTER; 5, 6, SCHCENASTER ‘?).
FOR EXPLANATION OF PLATE SEE PAGES 299 AND 300.
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PALAZOSOLASTER (?) GYALUM.
FOR EXPLANATION OF PLATE SEE PAGE 300.
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U. S. NATIONAL MUSEUM BULLETIN 88 PL. 35
1-4, SCHCENASTER FIMBRIATUS; 5, 6, ENCRINASTER PETALOIDES.
FOR EXPLANATION OF PLATE SEE PAGE 300.
U. S. NATIONAL MUSEUM BULLETIN 88 PL. 36
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1, TANIASTER SPINOSUS; 2, 3, T. CYLINDRICUS; 4, ALEPIDASTER FLEXUOSUS.
FOR EXPLANATION OF PLATE SEE PAGE 300.
U. S. NATIONAL MUSEUM BULLETIN 88 PL. 37
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FOR EXPLANATION OF PLATE SEE PAGE 301.
U. S. NATIONAL MUSEUM BULLETIN 88 PL. 38
EUCLADIA (7?) BEECHERI.
FOR EXPLANATION OF PLATE SEE PACE 301.
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INDEX.
[The important references in each case are in heavy-faced type. Synonyms are in italics.]
Page
RIAA ete sont! i= ats. cfo wins 'a'< Zia ania = 13 abnormal development..............-...---- 101 aboral, see abactinal.
BCOBSSORY, ACUINSIS 2.0 5c2c.c sce ces cietdacinsaes es 13 accassory interbrachials............... 18, 15,45, 46 BCCOSSUBVAMIAIES se cccm ccc cc cinisiacessan'ciaa 18, 47, 51 Acroura (Ophiura) schlotheimii............. 18 iG LITA eee ioelaists cielaicoleisiccieic's oes widinicesicjsiniecsicce 13 GQCUIMINGHUS, CA SCETIES <2 ion 22 isco wes scsceaes'se 93 acuminatus, Mesopaleaster (?)............-- 75,93 acuminatus, Roemeraster (?)..........-+----+- 93 adambulacralia, see adambulacrals.
adambulacral oral skeleton.............-.--- 16 BAAN PMACTAUSDINGS. 2525.2: ca'sj0.0,c%\ciseiccewelsiaiee 13, 43
adambulacrals (see also lateral shields)...... 18, 34, 43, 162, 213, 214, 222
PAC OMTIAGLOL sep isyeaitc see << cleit cig 40,49, 128, 131, 133 PAMEEATICIS see Selon ys actiale aio cletasciare elacieeiaissce= 132 PAP ICACINECIIS Sos c.cic 2 aco 2 o.- ccieinis e:deiceiee's mete 133 PACVITRIDNIBNSIS |S oicls,2.s. cave cs'u ss ieeseeg aicisasiae ols 132 PEE CPAP IAS Ee mae oF (foe io Sic wie oe atuienanclsele etre 263 Ben PROP AINE ele Saticin's oc cia bicie Diels oicicie'sinwies wcicers 264 AG) spe Muller’ and. Gurley’... .(6.<...c:ca'e0-eisie- 251 PA BD ATIAG COM cea clists ctasie'ei« os s's)sic.e bolslooesieleis 246, 263 PATO DIAS TEP se a5 ts s ccjsis cies woints's = wets aoiste 216, 228 PAPMAEESTLOSUS sree aera ieicieicieis cie.c,clswinilele cweid wins 230, 231 ME PIAUEMMELUS Siac cicios cocics sncsicee cece es 229,230 PATOL PUUMIIES tale micieteia soe Sanne ore aie STS Aste oS ase 264 PAB UIAITRGN GIGS i 3 21So 2 co ae cla etna cieninaee e 230, 233 PAPAS ED eR oral As aleve oeicie ans eStore tieiciaseis aicte'e s 230 ambital and ambital plates............. 18, 46,174 ambulacralia, see ambulacrals. ambulacral oral skeleton...................0 16 ambulacrals............. 18, 33,34, 41, 213, 235, 258 alternate arrangement................... 138, 33, 41, 152, 172, 174, 213, 214, 215, 222, 226 opposite arrangement.................... 13, 41, 163, 213, 214, 224, 246 AMETICUNUS, COLASLET 02.222 ocvcccwencoccestics 146 americanus, Petraster (?)..............06. 139, 146 PRIEEIEL ELS eee ie crernictale, laf ctsyeisizjsn'alcicieie ain aicis = 213 MUIAPOVOUIN Gs 5 iofo. nin csercjere vad atkssin ce ss 18, 89, 54,61 PSHOTUHSS (OE Yi<io n'a 51<\='si2)- cisiaralc's c= Secs 41,42, 43,50, 125 PST MONGS Se os cc vielnencecucaoden eeu enuts 3 127 PATIO MPU ASTOMALIOS s o's sina cic oie inicieeicice cieiersieie 62,74,125 anthonii, Asterias........ eenae Sees ace 146 METATUAV EAT UOSLEN sano oinio cic. Reieiemineiciean at=6 ee 86 antiqua, Asterias, Hisinger................... 149 OnGUAPASIETICS, TTOOSt. «22 ce cccecccacecvs« 86 CML EESTI OV OSLER s «<8. 55cnscccessetcscs 149 antiqua, Palxaster (Argaster).............---- 86 antiqua, Palxastering......2.0ncscececcccece: 149
50601°—Bull. 88—15——20
Page, GNUQUG PaUMiIDess ccc ec ccrcscecle Dasisscecae 149 antiqua,Perrasteni(?) = so222 2 ccd. ccstteees Seen 86 ONUGUATA AStETICG SS 5 on. cade eens cace ness 109 QNUGUCLO PE CL LOSUEN ie tatan =~ a2) Ss ses 109 ONLIGUALS, ANSCETISCUSS 25 oe cone oe oi clee <n lie Sele ole 149 antiquus, Lindstr6master................ 149, 153 antiquus, Mesopaleeaster (?).........-.----- 75,86 ONLIQUUS; PAlLIStene sense ten Sait a cs isiae asco 86 anus, see anal opening. approzimata, Palxasterina................-+- 142 AT CREOStETUES = <iatsiwisiclnasidisisicesals 5S ajaictarslols wicie 129, 130 arcs, see axil. VAT GASLEN Soe cie sees ec ns coc Oe at 74,77, 87 AION QUAN casas Sead oust innlesdceismctienses 86 QINolli, A SPidOsOMm@s > cncceccsacac sos caceee ae 243 arnoldi,, Wncrinaster: See acineneecenes 241,248 asper, Onychasters sevc.2--. sete ce cee ne 270,272 GSPETTIMNG, ROLEGStED sta 2 fea -astese neces 187 asperrima, Urasterella (?)................ 175, 187 asperrimus; Salteraster ..2 2.0 csc cescccsciccciee 187 GSPETTUMN US, LCL OSL ET ss jac te occ sasaeeniecsis ese 187 QSPETUUE, PASECTIOS. < Sia:0 opeizrainto.de enieie sinciae'sc= 188, 262 GSPETUIG, ROCTLETASLE?. «2 oc was wise ccinjacwanje vee 188 asperula, Urasterollas). satciccciewiclecwe cosets 175,188 A SNIdOSOMG = \.). cs'nicce Sassrstee ss etese esses See 241 PAINT NOLEL tricot Oe ee eee eee eee 243 FAOIOLONSO bre erate cise nciereci etree ae 244 PAS SOLGIUSSIE. o-oo e toceckaceeeseenwesees 243 EAI PT AV DOR seein sees coset ere eae seen eae 245 ASS POLBIOIdeS za smn sowescee sss eee omnes ces 243 A. petaloides goslariensis...........2......2- 243 AVP DOTS Safe ctose eralmiatstoisis miclascielsssrsinveleia ise atsleicte 244 IAS, TOOMEOTL = Syajets) a's oraiainis sialéolaleiais sinis eisjsisieisielceee 244 AS SChml G tlt rs sq) ohe eteeioe is Oe sete eee 244 Ar CISCh De IMI ANU eer saree eer ose cee seniors 244 AISTHCOSON CHAR a ores alae ataatats.<jatatote Saat 241 PA SLOLIAS |= 5.2 /sie,sia ctataielsicis'e cialis stale algae arses 33 Asterias Graham, Anthony and James....... 146 AE COW MINGLUG Se oe cctcteve aie clas scien eine eee 93 A OMERONM era = nin cicie'ecte «3 palo Seiceiseoeeeeenee 146 A ONt Gua RISING OR sale raise soa eea ds sntese ss 149 AFA OMTIGUA LITOOSU jowina siainie sins vane eemasie sees 86 Ar OM GUULE ceca cae eres c see cam aaa neces 109 A OSPETU Ets cece seme nace ere eee eee 188, 262 AVN CONSLELUO Sat otccee Seeman sore tenentacaene 187 ANNE wcrc Soisiniccieeialcinieiwic/eine stolons os ciate las 57 ARON UUE re ca coetn rina cece ce eaieaatcee 189 Ala DT SNICUG =m a Nara slawcnaaceee set eece estes 167 CAT DTUMOTOISerecees emacs chert cn secee se 108 A. (Archeasterias) rhenana................- 131 SANs SPINOSISSIMB a ae reciorcnwoe ae wlan sce ce eee a 19 asterid radicle= 5508. 2 cncses setae csecoctes 34 YSUERIN Rosaceae nace ee oe ote te 33
304 INDEX. Page. Page. A SLerisCULs GNUGUUS set > ene sen) eee 149 | Cheiropteraster..................- 40,199, 202, 252 #, Kita Ute Seaenonssdepadsoorosonseoce 41/4243 0 ji @ngigantouse ane sc ecter es ee hee eee eee eee 202 evolutionOfscsec assess ae- a 11,30, 48,52,106 | chemungensis, Devonaster..........- Fascias 101 number of, in Paleozoic.........-..-.-- midis 28s) CHOlaStOn. crea: sesec ee masecic so see eee ee 265 Leignittnly-a cs seueasemarAsmossacdosasace 13) aC peculiaris.. c. tease cease eee 266 AStropectenaaesc eee cue see eee meee 161 | Cholasteride............ SO ep ira ee 246,265 IAN (pyisehliiterivecsceer sec one saee ace een eer 160 Peiliaris® Ophiuras=. epee eee a eee rereee 268 AtaxaSler: ot scecneece es eee scorer sce cer rnc 161 | clarkana, Palzaster...... Ph ee Rees 61,63 A. pYgM@Bus........-----------2- 222222222 161 | clarkei, Etheridgaster...............--.+---+-- 172 Auluroidea........ 80, 38, 40, 41 , 42, 43, 163, 212, 218 clarkei, Monaster:. 3 0-c6cee pe ee ee ene 171, 172 geological distribution of........-.....-- 28 | clarkei, Palwaster, De Koninck............... 172 number of, in Paleozoic............---- 27,28 | clarkei, Palxaster, Miller..............--..-.- 61 Australasters..c-cceseccne ose 44,45,49,66,72, 171 | clarki, Mesopaleaster (?)..........--------- 75, 94 WA GipanteUS= a. ose se cen aaa saree aaaeeeeee WSs iil clarks Paleasten:s=42-oee Ase ee eee 94 A: (2) stutchburli. . <2. o oes nese ain 731M @lassitication ss. shy eae see ee ee 51 MuUstralis, Tentastere) sce a \<)2)-lnleissle sora leek 236.) HOC ESLER othe Se eia Roa Aco eee RE 95 URAL Ue Nt eerat res 1 Cen eee CEE Ie Ma Ca MeTICUNUS oe es oe eee 146 axillany,inframarginall: 525 eeesee cick eer ee 143) ON atiscatabusieen: face hole Soho ae eee 96 axillary interbrachial sc. e. casera cee l= dv tGStentiradiatuse se: eee ee eee 19 axillary marginal coon acto see sea 15 | colvini, Palzocoma..!..........-----.++-22+0+ 253 axillary OSSiCles ene == ceaen ee naa eer meme 34,49 | colvini, Stiirtzaster............-........2.-.- 253 babcocki, Lepidasterella. .................--- 1607; Gompsastel-ssas: sokee ee eee 192 barrisi, Onychaster Ope tdonée sechapoee cet 270,272 CUIOTMMOSUS oo Sse Seren ree eee 193 Garrisi MerOraster (i) senescence coe aa ane 272 \ G.n. Spi ee ee eee ae ee 194 batheri, Hudsonaster..............---- 59;16.05,460)))) (Compsasteridi..2 soe tens eee 162,163,191 I dellacomiae! Seat couse aes 248,252,254 | concinna, Eugasterella (?)......----.----- 238,289 IBAVELMUUOLMIS sesere ese ee-= se seeeeereaeee Zod || concinnius; Hugastehrs.<.- 2-6-4 eee ee nena 239 beecheri, Eucladia (?)-. 22... ss0j2- 222-2 «te 278 | confluens, Stenaster (?)......-.-.--------- 165,167 bellulus, Mesopaleeaster.-...-.2--...----=-- 75,91 | confragosus, Onychaster........--..------ 270,278 bellulus, Petraster...... tae a ogee Si asia Ol ll consteliatasy A stertass. =) i. cesese 2 saa asceeeee 187 bellulus, Promopaleaster........-.-- 104,105,118 | constellata, Urasterella (?)..........-..--- 175,187 beneckei, Bundenbachia.........-.-.-.-.--- 234 | (coronella, Paleasten= sates siamese 167 bibliography ce essscs aoa -iecetee EC aees 281-288 | coronella, Stenaster (?)...........-------- 165,167 biforis, Protaster............-----2+----- 226, 227 | crawfordsvillensis, Neopaleaster.......... 135,186 DivdUM eee sec ee ee eroeee eee ree te 14 | crawfordsvillensis, Palzaster...........-.----- 136 odyawallac rs pe bc ak acinar sap acon als 14) Cribellites\carbonarius=- 72.2. : 222 -e-ee ene 274 ibohemica, Hophiurays 1s...) 2-21 = eee 222) ||| “Crossaster= Siew seo tonne cs eee 38 ONCMUTSs cee aec cee er lec eee eee 216,228 | Cryptozonia.... 80,33,38, 40, 41, 43, 44,45, 46, 47, 162 Real nes se esse eecee eens eee 223 | cygnipes, Palxocoma..........----.-.+------- 253 bonneyi, Palzasterina............-.--.- 22.061 153 | cygnipes, Stiirtzaster..........-...-....----- 253 bonneyi, Palasterina.............. --- 151,152,158 | cylindrica, Lapworthura.............--.------ 220 brisingcides, Protaster............-.-----+++-- 236 | cylindrica, Palwocoma.............----------- 220 brisingoides, Stiirtzura.: «pe cciedeee misters 236 cylindrica, Denture eel 220 uccallprocesses seen on nw secant eee 225 | cylindricus, Teeniaster......-. 216, 217, 218, 219, 220 Bundenbach oso c ese we cial caine melas rela 29 | daoulasensis, Furcaster (?)....-..-..--------- 261 Bundenbachia.........-.....-----+-+--++ 216,284 | daoulasensis, Protaster........-- Bo MENS Saas 261 BPONeCKOl Co <= io -o.5i(o'o oisers a ecient eA ste 234 | darwini, Echinasterella (?)..........-...---- 200 BBS OTL TULYS sxe ol oyeie fo oor lal eS eetayel lara eerste 235 || decheni, Holuidiass...:255 nae eaeee eee 262 ceeCal POLeS 22 eeelnee inne re eeees ee ae 14 | decheni, Eophiurites:.................-+-++--- 262 Callin sten ca emle ls ae eat Me eel efe att Pa 190'') decheni)-Protaster<csesec22 5 eo ee eee 248 OCONEE Nea area nine oie sere ga 190 | decheni, Tremataster (?)......------------ 247, 248 @alliasteralla: i 822520 eee 39, 47, 49,50, 190 demissus, Onychaster.....-2-..2-2------<- 270,274 CMe ss sien s sje e niece sia’woneie =o ee 191 | development, abnormal..............------- 101 @altiasterellidse =< /-2- 52s -- oes see 162,163, 190 geological, of Stelleroidea...............- 27, 28 Caluastenid 2s ose = oats se ene eee 1901 savorlas ter e:..cscsokcasecackosee eee 40, 44, caractaci, Mesopaleeaster....:........-....- 75, 92 46, 47, 49, 50, 74, 76, 77, 97,129, 130, 133 COTACHICT, PGLBOStER ae alan nyo sicietetaiernlal=l operetta 92'9|| Spi chemunevensiss... <ses<cs5-425-- eee 101 caractaci, Protopalwaster...........-..-------- 92°"\!' ) veueharis’.os dae cece oes 29,37, 98 carbonarius, Cribellites. ...- 2-20. 5-- = -sieseeni 274 | devonica, Palenectria...........---2:--- ee >] 65 carinals, see radials. devonicus, Palasteriscus.............-.------ 200 catalogue of Paleozoic Stelleroidea........... 51 ||| @ifficilis, Tremataster..“seec2-0 50 -2s-eseese 247 eataractensis, Mesopaleeaster (?)..........--- 10,89 il isk... 6° 2-2 ce ee eee 14,213,225 central disk, see disk. how. enlarged....... 2... 4s-5- eee 32 central disk plate, see centrodorsal plate. disk accessory plates. ....-<|.--=-<---.-s---= 34,46 central plate, see centrodorsal plate. disk ambitals2. =. ---5------ @oeeeee eet 13 centrodorsal plate. << .<<cccimcsscsse= 14, 34,35,48 | disk inframarginals...............-...-.---<- 15
INDEX. 305 Page. Page. disk marginals... S22 seme neencs cece -cteccces L4G AE CLOT R G4 sosnig-cic Sassi sme ais oc cacaee ern omcanslnwe 172 CUISKAD IGS wee cee cinee csises daca tesatacecsceces 14 | eucharis, Devonaster..................... 29,37, 98 MLIMSLy:- cee ac aic css eee sce 49,179, 184,190,191 | ewcharis, Palwaster.................--2.2.2+-- 98 disk supramarginals.......................-- DP eUCNATt Ss x ONOSLON cu2 2s cscs eee nce ae oe ae 98 MISPAT: ON ONASTOD sc oce< sac csc sew nccsces «ox 120; TSU, | Hucladia . 3.2 .02052ck02 o208s2ctces meses ste 275,276 dorsal, see abactinal. [Bis (2) PEOCHOD ac cice.caanceoa es seeeseeee toons 278 dorsals, see radials. Hs JONUSONT caer fe coe = os omtees San ace acecre 6 276 Corsal Stield: see cece corec< seas tesee saecaa x: D138) | AB Wood Ward) 6c... <2. ces cecnt cai came% oe 276,277 dorso-laterals, see accessory plates. BIGIACIIG tosas:. tat aoe en sae oes 2 276 drevermanni, Miomaster................-.... QBs weg Ost ET soc eres sence eeepc re eee 237 dubius, Mesopaleaster (?) .................- TORS Bill kre CORCIONUS <<. ote rccie e/aiw nrate s/nceiesiciaiemierceta ee 239 CGULDIUS POISUSTET «non ace noes o0s- 5% a secccaaic Steers LOGUE ann ene waiseae-ae «cients si aens cer 238 MY Or ELL EUSLCT ems sete eae ccicic coat vase na 120 | Eugasterella....................-- ---- 235, 287, 259 NIELS ECL OGLET@@ thcinc ceelvic ca< cae ese ose 120) Mei?) concling ss. -25 4 e.jesse-asee <aceonc 238, 239 dyeri, Promopaleaster.............-- 104,105,120 | E.logani................. aed mee wee soe 237,238 WehIMAS teas acdcdesemecceteee cause ene 45 | Huophiuroidea.........2......20.ee ee ccecceee 213 Mehinasterolias.- +2220: s.-cses-ces eee ee 199,200 | Euryale annulatum...............-2--2..... 20 Wee) Oatwitll-ssccseaces cece. teeeccmen cen ae 200 | Euthemon........... 6t.o26 bb aaceanece 275, 276,279 HSA GNiase se seer eae oe eter ine care are S00 eh POIs esac ece ee eas soe cee eee 279 HChinasterias.. =< .<.2s-cec-cccthes 38, 207,209,211 | evolution of Asteroidea.....................-. 30 BAS DIMOSUS St oe tine pales nietenee was osacese deeasae iis |Werculplirs: Paleaster oo. oacsesaesses oe sce eee 117 echinatus, Squamaster..................2-.<. 249 | exculptus, Promopalaster........... 104,105,117 MCWIN TAQU Of: cssacccscscccmacc coe seawcees 35 | eye-plate, see ocular plate. Echinodiscaster...........-.--- 38, 40,207,209; 271 | ferox, Palseodiscus..........2s<s--e2-2<se000- 23 E. multidactylus...........-. SS rece em 211 | filiciformis, Helianthaster................- 159,160 SCHYTUOULSCALES oreo co ernie aeialciata siete Seccion Lee 211 | fimbriata, Palzasterina.........-..-.-.-..-.-- 204 FO ITLOUASCINS sia cicmiec ack soo ein eee ene QUEM UMDT OL, <P TOLasl en aaeeee ec akin ceen ees See 231 Ts MUA CCH UES = ols oe waws cece scans esses sess 211 | fimbriata, Prorasterind ..<..ceccesccsfss-ccee 231 Echinostellas...:.:2c-00-6-2002--..- 38, 207,209,212 | fimbriatus, Schoenaster...................... 204 A QUAITE ss ons ccce choses ecame caine cimee cee 212 | finei, Mesopaleeaster......................-- 75,81 WSTICIASEOLS oo -jcse sarcteseinaee nice ee cce axa = IQS SASS. || PiNet Paleast ena ecco = xnim oicivmsiscien esas eee 81 PeoOLIIMs TIN esos Se ees seen eas ioc oe cre 184 || eilexilts: Onychaster.222.... =. .<-Ses seo oes 269,270 eifelense, Aspid0soMG..........2.----0--22-005 244 | flexuosus, Alepidaster...................- 230, 231 eifelensis, Encrinaster...................---- O44. | flexiuosis; Protaster.vicce sc. sce 2s sees essen 231 elegans, Protaster........2-02020ceceeeeeseees 291 | flexuosa, Protasterina.......-.- ae ee 231 elegans, Teeniaster..................---. .. 219,221 | follmanni, Hifelaster......................-.- 134 elegans, Xenaster...............-..-.-2-- 130,181 | follmanni, Palasterina...........-..--- micheal 157 Glizae, Wranaster: 5. <.sc.c-ecescccccsecsacies 155 | follmanni, Pseudopalasterina............. 156,157 Encrinaster (part)......-..--.2.02-02eeeee0e 904. or besi, Hallaster. .«.-52+-c=sss2= 2nc2- cee 254, 255 FINCrinaster. <6. -/-=--2-42<2225-c0---- 43, 45,226,241 | forbesi, Protaster......-.....22-2.202.220000- 255 MeearnOldd sco cscec-cissececccce a hee m aces 241,248 | formosus, Compsaster......................- 193 MPMON BI ONSIS ee on se seca eceieis cists ciel oisters tasecnrals DYES) bel ab hye: S12) da a ee MRCS ME sors ae 248, 259, 261 APO SS oc. ssc 2ceschcnis so Seeenceasiecceaee 248) | We C? id aoulasensis 5.5.0. 0.<'5 wc osecceenese ane 261 EAC SOT AV ED: ou :sleca sak oo oie mie mictas sien claps on 945 | EF. palseozoicus........22---2---2--20-esc sess 259, 261 Bre POtAlOICCSs,<censarecine sscsie ese ewesetees tine 243) | PUNCOStEMO Sis. 6 a endeeecescs ss essaneeeene~ ee 248 E. petaloides goslariensis.................... 243 | genitals, see interradial plates. IONS a obs 62 Sole ki jom ies seine p ase seers ocls 944. | -gonitals'in, Echini. 2.ca-.srcses =< cessseeooes 35 re TOOMOTIn cscs vices nwo ccaccenistecateecmenc 242,244 | geological development of Stelleroidea....... 27,28 BS SCHUUG thats care cc scccecs oceceesccdecceccec 244 | geological distribution of Stelleroidea........ 28 WabISCODOMIANUS. 2.5. -2.52-c50- 0262s ee< 5 244 | giganteus, Australaster..................-. 78,171 TUCTINGSLENTED (DAU) aio ano aee oa aica = ae an ale 215 | giganteus, Cheiropteraster................... 202 WONCHINASTCLIGLO. 2 200ccece cesses acsee--es—- 215,241 || giganteus, Monaster. ccc... ocnceeaseeans sae 7 PANICTES ae Soc aicie eta s mcisie sia'stecicnsire cele ania 173,178 | giganteus, Palxaster ( Monaster)........ eaxete 73 EU SINL DUEL sais sia scic. care ok wiels oS .c.0'> nea ca sire mune 186 | girvanensis, Urasterella........-...... 167,175, 186 OMG A eeeeaclewicc wuisiecs denleieis vwocisidienis.cesiessen 262 | goldfussi, Aspidosoma..........-.-..--.--+++- 243 PMOLOCCNOM =. sec niec oct DacwieccacajcceSensen eer 262 | goldfussi, Encrinaster......................- 243 MOUMM NADY Ss occ nt oe Ags Sane nio'etieiceiere PAG 262.0 QO SEE rons acnnnenwice sense danv so seisue desc 61 MOpHIUT dessa. ocd 22 2c scenes cornn-e 216, 229; 223-259) |’ prandis,Agalmaster ..........cc0cses~eseseswes 132 [He DONE CR ss Joc. oic cases om 0 cccivsminsectcoes 222 | grandis, Bundenbachia.......c.eccccecaseces 235 OD IWUITIC = a ctarnteannieecsieice mas cocina sects a. 262)) ‘grandis, Palssophiomyxa....:.:.........2< 234,285 HODNUNSCOR sac sccaisecssase oso ous dr dbeaanent oa 202 I NGTANGIS, STENGSEEN oa ole decd deinen secs veces 180 LOMUCCREM So tocec ess cca veeenrekinSanaee os bus 262 | grandis, Urasterella.................. 174,175,180 IOSDONOY US cect sc co-cecadernas «aesniaysin- 262,268 | granti, Mesopaleaster .................-..-- 75,89 Bp ELLIE OIINIS 2 x\ors'aiainic joe ob 8 sialo we stwienew see 26851) OTOH; EGLLOSET Sn 6o caencieu nice succeractossoee 89 EANOTIDQ OSCE soc cisc'cowiavic's ocicisciccess Bekiacemee 70 | granuliferus, Alepidaster................. 229, 230
306 INDEX.
Page.
granuliferus, Protaster (?).........-.-.-..+--- 230 granulosus, Palxaster, Hall...........-...--- 112 granulosus, Palxaster, Meek. ........-....--- 109 granulosus, Promopaleaster........-. 104, 112,113 STASIS - ese cesiteaaa seas eecie sie iene 33 OTA Ls AISMIMOSOMN Mesa = eee cn ee eee 245 graye, nerinaster!(?) i.e ees stste 245 grayl Wepidasten®.. <-semseae ens ce seni 158 eregarius, Aganasters..-22-sccc--c2ss2-eecine 264 gregarius, Alepidaster yc oo. 2c sec -='-\sisinieltatcl= 264 GTEQATUUS, rT OL StEN (0s) 2 n= \a\-iaioie'sta alsieicietae ieee 264 Groeporiura. asicssctecae je accent ee 216, 238 Gsspryd scm eetesissecs awe secs aac ences 234 grororyi Palsosolastens.<-3<-c-2s--ctesee 209 groomi Protesters cs... cc ccensnciniee Jassie 226,227 gualum, elianthaster: 2-222 -<ce soe tee 160,210 gyalum, Palzeosolaster (?).......-.---------- 210 Tall astenee aca ncchisctacce ete escm seer 248,254 ITs LOL DESI siaiciasae sae vacc eee ecienanene 254,255 Harris, I. H., gift of starfishes by............ 9 MOTTiSt sR OLCOSten sana tes eee ene eee 180 Helianthaster Clarke (part). ....-..--.------- 209 Helianthaster Roemer ....-.2- 12... 55. -c0.- <1 38, 40, 45, 157, 158, 159, 209,211
FS filictiormis s-yano- cs eeeaeereesemee eee 159, 160 Te GyQlum) (Part) -ce-)-. 2 eet ae sea 160,210 AS THENANUS ss asia s eiscists esis sclaleiait ese ie oie 159 Is BuUyal an beaercacorogonenotocdapsccessonsdc 209,211 Le MSD ri Clarke oe aden eine ele ae neers 160 CHANT Astenid eee ae setae eee 157 Helanthasterinawar cscs acces see ee 157 Frelidcteni..ocesnssmccnnes ma -eaee eee estes 38, 208 hinndoNPalvasten se ono sss setae 188 RiTUAO VULESEEN S «ae acne cana eee eae eee 188 hirudoWrasterella Secon. eres oecem ese 175,188 FLISUNG EN ASEET a. aici tascinis, « nalnnicle Dee aos seeiole 148 FT OMI GUE 25 oo sane inane scene eee laseee 149 Miudsonaster <2 .)</s<(\sj=cviste e-islecieteelercte 31, 32, 34, 36,
38, 39, 40, 41, 42, 44,45, 47, 48, 49, 52, 58, 69, 75, 105, 135, 140, 158, 165, 179, 194, 196
DEG OG eee iin (ition sate eae erseats 55, 65, 167 EPeINCOMptissce acs se se 34, 36, 40,55, 61 AS matiwtinus <2. 3-02-11 34,55, 57, 139, 141, 166 pmTllord: «socio cs Ss soa e ows aS 55, 60 FL: NGITAWAYde~ 2io.oc eos. oe cece ates ais 43, 50,55, 59 EP STUPOSUS Se ane n1s- see Meee eee eee ee 36,55, 64 Hudsonasteride’............ 5 ae eee 52, 58,162 icleyt | Stenasten seer ana heen eeeeeeeaee eee 182 huxleyi, Urasterella 5-25 2 ise aes 175, 182 ipermas Mithemons eestor 279 imbricatus, ‘Paleastens 2. eeesiweton eee ayaa 169 imbricatus;, etraster (2?) o- o-..ae- eter 168,169 incomptus, Hudsonaster........... 34,36, 40,55, 61 INcOMPLUS, PALLAStET.. -—. =< <oeiae cece wee sense 61 inframarginalia-ies-2-..-.- 5222. 15, 34, 48, 152, 194 inframarginal plates............ 15, 33, 174, 179, 185 interactinalsicjae sees sd cass coe oe gece ae 13 interbrachial adambulacrals............... 15, 126 interbrachial areas and arcs.... 14, 50, 138,185,194 interbrachial marginals...................... 15
intermarginal plates, see ambital plates. intermarginals, see ambital.
intermedius, Agalmaster.......<m.--------.-- 133 intermedius, Mesopaleaster..............--- 75,79 interadial plates... 5.32. satamestemeteemeeae 15, 32 Jak elasters 5: asses weeaclsnosnie ee sees 40,192
Page. J. petaliformis 3.5 26.55. "a. hese sate eeceeeee 192 jahni, Bohemura 2. .-- 50 -2ee noe eee 223 YANest, PALeASlena lac <n's otic ese e > sie eee 146 jamest, Palasterina (?). 2.2... .2.-cse2-5se52-6 146 johnsoni; Mucladias:.-- =) .---5-ceeeseeoeecee 276 kinchont,Palastering. ee eee eee 155 kinahani, Uranaster=+.. -4-+4----4-5-e5-ee 154,155 Labidasters: Ssas.2= 5526s ssaeaaseass sees 208 lanceolatus, Mesopalaeaster (?)............-. 75, 82 Tap worhtura: :s2c8: ce. saeeenussenee 248,250, 254 Er. CYUNETICD ovens do cicisie ae Ieee ee ee eee 220 Tys-Miltonts: ccen. seep e once shee ee ene 250, 251, 253 Wi: SOllash ar et cet nascles te eee a te eee ee 251 Da '(0) SPos side tate. o,c35 sive Noe gaol See 251 apworthuridte: 2.2. 5--- = -eeeeeee eee 246, 248 lateralishiclds:2. 0225 hese. eee eee 214 latiscutatus, Coelaster............2--csec==-= 96 latiscutatus, Spaniaster:=-2.-s-sec. see eee 96 Jaxata, schuchertia: ===. 25-2945 -2--cces= 196,198 legrandensis, Schoenaster (?)............---- 206 We pIdaster=nasssccees eee cee eee 38,40, 158, 160 10s A ae BREA ASAD AOCOCSSOEe SG 158 epidasteracta .< cece sssine= ssteasiacen eos 53 Hepidasterella: 257.2 cis... < scccce-eeeaes 38, 40,160 iis babcockit = see se a. © ne acinee cee eee 160 Lepidastoridsese 3.2 eet eee eee eee 52,53, 157 leptosoma,, Protaster. .sc.-22s2s225- cesses 237 leptosoma, Rhodostoma...........-.-------+- 237 leptosoma, Stirtzuras.. --- 222.22. --4-seee 236,287 leptosomoides, Stiirtzura............--..- 236,237 Lindstrémaster............... 138,140, 148, 154, 156 santiquus ssc. cem oh castes ice eee eee 149, 153 Lindstromasterined. «<2... <0 1: -e cei en = ee 138 logani, Hugaster... 22.52.22... seateereise niece 238 logani; Hingasterellan 22 ee oee-poeeeeee 237,288 longibrachiatus, Palzwaster.........../.------- 115 Thoriolastersss=s- seen eee 199, 200, 201, 202, 252 mirabilis’. <5. occ nscece sec ee oteeeeesors 201 lymani, Ophiuring: -./2-- ----99ce--eeeeeeee 247 Ibysophitiney ooo. scans sateen ec eREee 215 madreporite..... 15,39,40, 209, 211, 214, 222, 223, 226 magnificus, Promopaleaster..............-.. 42, 104, 105, 106, 113, 122 margaritatus, Xenaster...... Janta eal seieeiels 131, 132 margaritatus, Xenaster............-.. 129,130,181 marginalia, see marginal plates. marginal plates.............- 15,33, 43, 135, 152, 213 Marstont, PAlLOCOMM.. 22 = oe a saan oe eile 253 marstoni, Sturtzasters.-.-/-s--o0-s- sees 253 matuting, A sterias.. 9.02 -e)a° ea cece see 57 matutinus, Hudsonaster..... 34,55, 57,139, 141, 166 MULULNUS, EQLEOSUET s ccjn a= acs «eee eee 57 meafordensis, Teeniaster............-...----- 221 moastiroments'’. -2))3552- 02 sic2-5- cn ose aes 15 median dorsals, see radials. MAGUSASTOR . 2c<s5. vec wlacueseenesete ees 38, 207, 212 Merhenanus’ j.j< 3.2/0: jcc 2/< seine eee aaa 212 Mesopaleeaster........-..- 28, 39, 41, 44, 45, 46, 47, 49, 50, 56, 74,95, 98, 105, 126, 130, 135, 158 Mi?) aquminatus.o.. sas e=. eee eee 75, 93 M(?) antiquus:.< cons soos oe 75,86 Mi bellulus soo. oe ccssacoen eee easeseee 75,91 Me catactacl oes sic0 <a none saan n eee 75, 92 M:(?)icataractansis:.. 5....4-.--6---seeeeeees 75,89 ME (2) eek cd ate eli atarote oleate eles ele aerate 75, 94 MiG?) da bIUS sneer occas ee ene peer 75,85 >
ae i
- nd
INDEX, 307
Page. Page. My TINO meee eer oeae nace Je ene ae 75,81 | Ophtura cillaris.....6 56 s.522005.20- ceca sen <n 268 Meeran there ete ooe sincnc swe eee e sete es (0,891 O <ODWISUSc cccecec. rcs cceeecusuenseeee ea. ae 25 Ms intermedius sco: icnis..sesimcscomencne. de 75,79 | ©. (?) ramosa.........0.-c0cccceencecoeccenee 22 IM:.(?) Tanceolatus «.<:5,.c%2 oceciecs sbewleesisnecce WOp Ss) (OOSTNONANGE 22. ccc evista eh micitios ae Beer ae == 263 IMS (2) PArViUISCULUS. <0...2 502552 <cce aot ece cee (O98 a). [RON Salar sae o ct feet ana st Sota sce Woe ascaeees 227 IM PIORVitUS: 2... —scies. ce tiewcdeceses- 10; 5o,500 |eOs schlotheimil.. 22. see veccceasenncceres ee 18 IMmSNAMOLTS ciejniicsSs sadcieice sede ecsscets AA TO ae | MODIMUTOSLETICN «~.oc-'2 eons teatneccesceseee 215, 246 Mi GO) WALDGLANUS vecs cine cnc cee ceeccedocees (O84 7| CODMUTEN Gan see aac we toa ne ot DOS Mesopaleastering.............2-2------- 52, 74,162 | O. primigenia..............0.2ceceeeeeencecee 263 miamiensis, Alepidaster...... san cebeasess 230,283) Ophiuring | <j..2 ct c2cccct co esscets se oeatee 246, 260 miamiensis, Anorthaster.................--.. 127 (Ot lymant. oe coico Reset scmice o-eteciebasalsees 247 MIIGMAUCNSIS, EC CLLASE EN. oe oye ae sce mde oece 127) | Ophtorinides = «..4cs owes sbec csi ccectenevccere 246 miamiensis, Protaster..........2---.2.---+--- 233 | Ophiuroidea ............... 41,42, 43, 212, 258, 267 miellensis, Agalmaster................-.-...- 132 geological distribution of..............-.- 28 millert, Hudsonaster.......:...0<+-<..-2.0<- 55, 60 number of, in Paleozoic ................ 27, 28 miltoni, Lapworthura................. 250, 251,253 | oral, see actinal. WAILO TUL ET OUUSU EM oo ora niin oa tata na ster nie eee O51 MOTAMANGICS «to seceee nate ence eee eaeees 16 minveri, Sympterura.....................-.- 256 | oralarmature ...........-.- 16, 43, 162, 172, 210, 242 NIDOIAS LAD so oe oa aoe ene saree oe 43,50,74,96 | oral skeleton, see oral armature. Ma GTO VerMann <:6/.2 to sacasecmc oases se sch 96 | ordinaria, Schuchertia..............-..<.. 196,199 MIOSNONGYAUSE cocoa asc cles su eceeeeeee 262,268 | ossicles, see plates. Mie ThGUANUS ses soe wena s neice eo cmen eo cine DES AMID SLDASLOL apres sect seme eee ese ese ess 10, mira, Calllasterella...........-...---------..- 191 40, 41, 44, 49, 56, 66, 67, 75,98, 104, 135,158 mirabilis, Loriolaster............-..........- 201 | Palxaster (Monaster) Etheridge (part)...-. 72,170 mirus, Calliaster.....-.-.- eee eee 190 | P. (Argaster) antiqua....-..-.....-.- Bin SIO 86 mitchelli, Sturtzaster (?)..................... 954) | BP VONHQUALG soc b esc cc oa cecsskcigeecseces oes 109 IMONaSstEn GregoTY is. : +s=-a-ute cere hose cesses AQ Dulles ONUGUS satacaae soot ee oss eee a a 86 Monaster Etheridge.............-.-.......- AQHA ZOMG CSDETTIM Gene ccc acacia Pee sense 187 Mis Clarkole.jasmesseee ss sees cee cece ctsciee TFT, DERE COTOCLOCL. 2S tater ce pees eee acess 92 DM CI ANTOUS sc an coms cnneee se ters oon ences FOU s CLT RONG suis coco wteicwsincoees bee omees = ee 61,63 IMASTULCROUT Hea cicca ists <elasncie vain eee Aone eceses WuleP. clarke: De Koninck....22.3s5-s2ce eo nee 172 MOnGSt CHOI: -ci\snse'eleieinin sisi a e,ces6 162516351709) Pclarkel, Millon. < ooo ese ce cee cee asec 61 montana, Urasterella...................-. TSU SON eis CAN Kies -nce a cc ciee te asec e- settee ease 94 MOTHOTUS; AStETIOS ss. 2 wens scedesseesmescees ASQW Mele COTOR EUs eae a sn tances te eames = tee 167 montanus, Palwaster................-----+--- 189) | Pocratwfordsvillensts.. .- 22-0 secs ose cee 136 montanus, Schoenaster (?)...........-....- ASSQOT Et Ps GUO Us is onrciao siars ore sts Sis:alslaes oa gfalainsn ase eee 85 mouth angle plate, see oral armature. DS QUE ncc oe wenn cee ce atwae endene cece tse 120 multidactylus, Echinodiscaster........ Beers OVP Reucharts «osc e nc ccin cee eeemestsisace Sacer 98 multidactylus, Echinodiscus................-- QTE WP MOLCWL DIALS cee 1k aie tereralte mais secs 117 multirayed starfishes................ SREAO e157 e207 eeeee heel = cae sca cct a Ge cane oar eae cle 81 narrawayi, Hudsonaster.............- 43,50,55,59 | P. (Monaster) giganteus..............--.---- 73 narrawayi, Protopalzaster...........-..---.-- SOU WEA OV aN tees cece nccces.-seteesecssaseeeceee 89 MELIOCtA, ESISSUIA. osscscme ss cecns sh seeeess ec 993% ||P. grantulosus Wall 2. . 2 oe ecent sc seecensese 112 Neopaleeaster............ 40, 43, 48, 49, 57,69, 98,184 | P. granulosus Meek................-....----- 109 N. crawfordsvillensis....................- TS5 51S Giles ROT Stages a oa een a 2 eee 180 INeopalmasteridie 5... ces ccccc denen Beebo aL 84g Pes NWUGO sae no seit C pao) ame ea = mtaominsarapniny 188 niagarensis, Paleaster...........-.--------- 68569) | Patmoricntus. 2. c.c- ccc ass2 ee seeen ee sane 169 ObiMsuS{Ophinra.. 2: sccccsecscesecsccwe- see D5 PS ANCOM DUS 2) aicin 2 ciate <ivjnie.<'s 3is(0is)sin.n swcistsie)sisie 61 OULUSUS PAILOSTET < Sac sade ccc ceetss <icceviede MG Zan eee TILE arate ic cat at ohe eect ag ee eet aaa ore 146 obtusus, Protaster (Ophiura)..............-- 25 | P. longibrachiatus...........-.-.------------- 115 obtusus, Stenaster (?)..............-...-- 16D; 0 C Ti) Be matutinusc. 222. eke os eee cece essere 57 QUPLSUS IUTUSLEN c ces care cicine Nose sacs ssecueceses LOH EPS In tensis - an asec cee eaeue as eeice snes 127 occurrence of starfishes...........-...----.-- QB! (PS MONMINUS «oc << cel a cadence ccueaerass 189 OCWIAY, DIAC ss... once ete cect 16534548, 184,5136.| Po niagarensis...... 22-5 53-2 - oes ae - = nage 68,69 ocwlars;in Wehini. 22.222 acct ecece se ec es SOG eR ODLUSUS cae cements cee seit eee ee 167 ontogeny of Stelleroidea.................-..- 86 3) PParvtusCuluse on voce <2 /0cicccacclcason se ~ -se 87 Onychesters 6 wes Scsdee sc sisainewvon det sese ns ZOE Meta DUC ELS ire a oleleistc nial sta e's wialeee esis eee ceca 178 OPASPOP 2s fs nos seats oases se nueee cence 270; 2225) PE. Py SMeas.. .----cecases ccsccws ose csazss 23 OSParrishiec. <2 Neos Pato eases cmb te DO Daa A Pe PUPNVENE cine mae ene vw vceineccecsccsseecseses 187 ORCOMUMS LOSUSs ose c2 ween coc arene roe abe: 210 waBe |: een lhc eves cesccnes todas erncs eros’ sisijac 77 Oademilssus ovis s00) once size de nseeeeetomartters DOV QTE NOP: SN DlEiaceg cn owe owas Soiecine ese ee reccwrse 61,62 ONS soe easiest see a soe aeminaccs DEO. STON Pio BDEHOMS oa.w «os <wraicictncieteicincie'/je aces oe a.csie. 109 Onychasteridesls 1: ssi. oc sses saede Saseee sin QBSi | LP NSDINULOSUS Yn 2s ins oascec escent san sens ae 115 Ophiocistiasce. 6 5</tse. eases sae we oe ees 275; || ides SQUAMIBUUS 56 os scence witade cc teciiscesien = 23 Onlto-Enerinaster is... ccscccs. ccc eteveee des 215 | P. (Monaster) stutchburii.................-.- 2B ODIMOPEGE Rome cacsescss cc stds scene cecawsesics ZGo FN ers MOILGET OTIS o cin(islare okie stoa'e oc vine osletonuie'sls SA
308 INDEX. Page. A Page. PA R0USONI Ss rea saa esas ian nese 106 || Palasterinids - ..<.<.2-2--:-22--0<+ 52,53, 138, 196 PS WY KOM are, = Soe BAAR eae oes ose ae 119)! sRalasteriscidee:.ce.c2--eecp oor es aces 162, 163,199 Ralmasterid sees steps eae one eee 52553 6G) ealasteriscussset ccs aus eee case ae 40,199, 200, 252 POleaStEniNG: Ors isos cae ae TSS HOU) pe GCVODICUSHE a he tacecee nc Nee ee eee 200 PRONOUN So 2 oon sok ce cement cesar asneee 149).\))) Palastropectenacesetescnck cee eee eee 248,261 P. approximata.........--- Sos sin see ee ae 142) Mp PA QIELE Ss. 3 Jade eee aeolian 262 PROOUN EY is haan cee Sane eee Pe ese liam ||) Palminesiantiquaescs. een. eee eee eee 149 PRAM OTUs eis coo < SS sace a2 Dees ee 2047 pap Ul pss Soe igo beeecice ee 16 PADTUM BUGS sas coin sins = Joe ese aa ae eee 153 | parviusculus, Mesopaleeaster (?)............ 75,87 PINS DCCUOSG = sayom oa ates ese ee se 142") paxviusculus, Palwasten....222222. 2... cess 87 (POLVASEETING Sis Soe en cae Oe 660) panvulus/“Trimerasters 222252 sees seaee eens 134 POULBOSETINIDY 5-55 32sec cece os aoa eee 13574 ||\pamillas sees lees oe Le ae 116, 156 PULeDrising idee. aoe Se ese eee 199})| peculiaris: (Cholasters 22>... 2: see eee 266 (Palsechinasterid 2 esse ee eee ee eee ‘199i pedicollarics ge: oe)2 4 kas. oe eR ie ee 16 (PAlegoniasteride (part) ees seeae sense ee eee 66,241 || perfectus, Siluraster.<.{:-2. 2.222 ere 66 IPGLLGON Stereo ee ee eee Sass ADSM) perradiale Sees as WS Sea ws Ae eee Pe 17 IPOLZ NECTAR os ees eee eae See 155 | petaliformis, Jaekelaster...................-. 192 PPRAEVONECH ze SseB too ae ne esa os Sas Soe LOD | CLULOTA ES SerAS DICOSOTO Seen Sea e ee oe 243 Palzocoma Miller (part).........-.-----:+-:- 239) ||| petaloidessincrinaster.: 52... 2.5. -.-. 2s. eee 243 (POleocomad Salterscses aoa nee eae ee 252 | petaloides goslariensis, Aspidosoma........... 243 Palzocoma (Bdellacoma)............--------- 254 | petaloides goslariensis, Encrinaster.........- 243 Palzocoma (Rhopalocoma)........----------- 254 Ws Betrasters os .ueecas. stores cee e eres tees suigos Piicolvingesee se pony ee ANE SE Ne. ROSS 44, 45,46, 47,51, 188, 149, 154, 156, 196 PECUONIDES Mae eno A ee ae nee Hosen ee 253s) |heral(?) AMeTICAN IS ssa: se > Seaiestn ener 139, 146 Pr icylindriets as 2> eho sdanc sas ce seeee 2208 PAE) GNU GU sae = see os eee 86 (PIN ATStON etre dee os ea eee as Sates 253) | Pbelilus:s sts ease cues ee eR Ee Sate 91 Pr princepsssss 2 ia. 2a 022tcesccesasccseoses D240 Mi PAY ent ees foc eee oe nis SEN Sey ern ee 121 PETUTOLECRTUC Mas aan ne ae e eee nace ee 254) || MPA rigidus:(Darb) ses aesee ce sacs eeee eee nee 57 PS Spinosassee sae seans sete ado ee ks aeeen ee DION BS ripiduss.2.22 See. ss seelescdt esses see 139, 141 IP OEP MAL ONMIS se oe so sa See soe bss asee eee 2540) Re Smythiatess sess sess senate Oak eee ae eee 139, 147 Palsodisens teres 265-52 3-s0 see et eee eee 2311 Buspeciosussie2: fsbo oes Se ktoe ss sesso 47,189, 142 ‘Paleophiomyxa toss soya seaee sae eee PIGS DSA) Pt eodlbenians 3. 255 3's oss See cs cese ose 84 Pe orandiswycsce ie aNeshscosseecee serene 2349788 balls pelrlerotasber scces us Aeccasaecee st eeee aces 25 Palweopniomyridse soso sss ens seas as sos 2155234¢')|\ Phianerozonia so ossci5), 2 bees eee ate 80, Palmophiurassacssesec asses ssa eee 235 38,39, 40, 41, 43, 44, 45, 46, 48, 51 Pisimplexesnscsccce teste sores see usseeeeeee 235 | phylembryo of Stelleroidea.................. 34 Palzophiuride 2. <2 esas asset sss sce 215; 2169285: Pisaster sos cecnel eee oe sone oe eee ee nena ee 38 Palsosolaster:-:-...--..-0. eee 38; 40; 2077 ZOOS 2115 plates. Jesel oes Se eee een nese eee 17 Pigregoryissc 5 ee ee ses SS a 209 | plumiformis, Trichotaster................... 26,38 IPs) Sy MUM aes essen ssa 210 | podia and podial openings................... 18, Bi roomeriva-.!35 2.22 Scat cet ee cosa eee eee 211 17,33, 38,39, 209, 213 Palssosolasteracea 526.4. sAs nso oe ee 163 || pontis, Aspidosoma?........2202- 222202 eee 244 Paleeosolasteridee...........--.-.2---- 1623163%9 O79)! pontis; Enerinaster: --.4 5252525052 ee eee eee 244 PULOS PON Yl os. Senn seeds ol temiee eee 248 | prenuntius, Promopaleaster.............- 104,107 Palweospondylus =... cse=2 sce0Seccssek ee fee 261 | preservation of starfishes....................- 28 (Palssostelias 20) 330.454 em jo ab es OL; 138) Lb, | primava;Aisteriagso 222552 58.222 see eee 167 Pa SOlidassetsnactemee sece een aecee ae eee 156 | primexva, Palxasterina.........- A atin Lea 153 paleeozoicus, Furcaster.-..--.....-.--..-.- 259,261 | primzva, Palasterina.............- 149, 151, 152, 153 Pale spOnaylus ters osce sao aca Resasoe se 2618 \primsevuss UTGSteTs ean as asa ee ee eee 153 BeAr de Eso hpe rere ee rsonebs sagseede adage 262 | primary inframarginal................--..--- 15 Palsoura sisson ss 2 2 SA eee Z1GS 22a) || primary radigist.. a sscee cee ae ee ee 17, 32 Pe MG BLOCbA stats era cites sa) -teIemdn)- sete 223 | primary skeleton.......- 13, 15, 17, 31, 32, 34, 56, 191 Palasteracanthion......---------+++---++-+--++ 173 | primary supramarginal..................-.-- 15 Palasterina Billings (part)..........-........ 195 | primigenia, Ophiurella................------- 263 Palasterina Salter...........-.--.+..+-::+-2 40, | primigenius, Eospondylus.............--..-- 263 49, 130, 138, 140, 150, 154, 156,196 | primitive starfish, most ..................-. 31, 33 Piibonneyii so a2csc scone ocssedeosen= 151,152,153 | primordialis, Asterias.............-....-..-%. 108 P fOllMONNE ss = esses ase See soe sass see eee 157 | primus, Protasteracanthion.........-.-..----- 188 BaP) GOMES tee satay eee tele ee ee 146: || princeps, Palsxocoma..s.-.-++--2222-252-e-e 240 PB. Rinaghan tin 255 3s a oss des ano steee 155 || princeps, Ptilonaster---..2..-2.2.-22-<-- 240, 259 PA primwevans s.i 22458 ase a 149, 151,152,158 | proavitus, Mesopalewaster ............-.-.- 75, 88, 85 PA?) ramsey ensis4 404s Gssee--acaae eee 162))254 ||: Promopaleeaster=:22-:02522-.-6--- sone neon 28, Pitrigidugiee e438 02 Ie. «eae 141 39, 41, 42, 44, 45, 46, 47, 50, 56, 76, 98, 102, 126 PorvUgogiiss <5 e555 5 VIS ys des acc sce eee 64); Papellulus oso. cc- cts ccssscuecekeaase 104,105, 118 Pi stellatas 3.250 ses. 2 0. SL ee a aS 106 Pediyeris 83 So eeeeehiaseticsemte eee 104, 105, 120 Palasteringesas. <2235545u5s6 jesse epee eons bd IF PRexculptas. sses..csscs ceed ssn sek 104,105,117
INDEX, 309 Page. Page
Pa PTANULOSUS 2.222 2220s. cen tewcetce 104, 112,113 | ray ambitals. ... 2.2.0.2... ccc ncccccccccccccs 13 iP. Magnilicuss...< 2--.2..-<< 42,104, 105, 106,113, 122 | rays..................... 17, 38, 44, 48, 207, 213, 223 IPA PIENURUMUSs ¢ o< sc<.5- Sozce cee blce scence 104,107 TOgeneravion Of. -2...cs-sscsescc ss ees cee 185 IPSSPOCIOSUS 55-6252 -eesce ves 104,105, 109, 113 | regeneration......................cee ce cnee 37, 185 PRSDAUNGOU ee oes ck sete eke cows 104,108, 109 | respiration, see papule and cecal pores. IPaSDINWIOSUS!o< <0 clicnceces ss scee 44,104,105,115 | rhenana, Asterias (Archxasterias)............- 131 PAwilsonli.s. o.oo. -in< Secpaweemene eee se 104,106 | rhenana, Ophiura..........................2- 263 IBA WY KOI ose seas soe cance cinares ideas 42,104,119 | rhenanus, Helianthaster..................... 159 Promopaleasteracea..............-.-..-e00- 53 | rhenanus, Medusaster....................... 212 Promopalesteride.................-...-- 52,53, 73 | rhenanus, Miospondylus......... pet aetion ase 263 Promopaleasterine..................2. 52,74,102 | rhenanus, Xenaster (?)..................- 130,181 Protaster Hall (part)...................0200- 204) | SECHONASON eee cates eae hone ee 43,128,133 Protaster Forbes ................ 216, 217,224,229 | R.schwerdi............ Sales sistent oe lence, 133 PA MN OOTTISt se Secccc ode Sees s2sasecndeoseeneyes ioe eu ROGOSLOTUG sane ae ase eas aia iaietce een alae 236 Pe DUORIS sess S55 oa soci accigsinan nen on DIG, (ae il ales LEPLOSOMA. 2 occ cauecie sae cous ce sesebccsece 237 PPOTESINGQOUDES « osc:cralein ow ie ca ee ne sececee cele 236 | Rhopalocoma........................- 248,252,254 P. daoulasensis....... Bee Nee ha hte teen 26], | Re pyrotechnica.s.22 5 ace sce oakce se 254 IPMQOCKENL a alo 5 oe oc kere endhioncniesines 248 | rigidus, Palasterina.................-..-.---- 141 PPMCLOU OTIS aa mrss oe a Ie a Marea Snares Sake Saas DON MN TIOCAUS MPELIOSL Cac oe sano eek acca en ceeee 57 IB MMO cian c an. a ooeaa cacSoesee Sekt sewen 231 | rigidus, Petraster...................2.0000 139,141 oat LOTILOSUG sen eee Bie no om orale dlanes eee ewicils QOL ivCOMLCNASl Chee =o fine aac seen cnee ee ec aseee 173,177 PT UGS nee ee BA eek oS 255) |) de. (7D )iacwminatus:-. <2 cos oe ccc encesesce 93 PPE) GTOMANL ETUS «<< occa sre. c's <.ccaceececdacceis 0 PeaGSPen Ula a= - aoe see es» Bed edd dee ee 188 PEE QUEQUTIWS oa wcine v5, fieion nse eiseceeekes oe ase 264) | Roemerdstenince... 2. sccsccncs iserecuecccestse 172 er PLOOMM craic scion ccc ah cece ene iene Sec ed 226,227 | roemeri, Aspidosoma................+-sesee0e 244 PEP LEMLOSOMUD cio a a)e janie ode syala wnincinice cade eee owees 237 | roemeri, Encrinaster.....................- 242,244 PENA INICNSIO sc S228 smc csieseeeesaeeaecie cinemas 233 | roemeri, Helianthaster..............-....00- 209, 211 IE LLOUB SNe cto ce alee Saisie sad atl ocieie 251 | roemeri, Paleeosolaster...................... 211 P. (Ophiura) obtusus.....................--- Db i tugO8d, IROIGSteTING: oc... 242 ane ncceceseaserie 64 DOU erate oda pin cione os Saye eh scmaieainmneceiec sere 25 | rugosus, Hudsonaster...............----- 36,55, 64 RUD) ISAITOM Loe ox coe. ns ales aes keene omseaye 226,999 | ruthvent, Palzaster. .. 2.22. 20 5-.-aoscectesienes 187 ee SOU SWICK: 22 sn sescs ce ociee tases as 225,226,243 | ruthvent, Uraster:... ..2....200dceq- ones = cece nae 187 eC SUGULUON semes sce nee occ nesmesecincen 226,228 | ruthveni, Urasterella...............-. 174,175,187 P. (?) whiteavesianus.................-.- 220 5209?" || QUENT ESLER ae oe ccace aactse ae acces sane eee see 173,178 Protasteracanthion... .........---2-ceccceccee RB; 178 | Ssasperrvmis occ. 3 oo tc esse ec easeee'see 187 MDT ae on Gcce se hence ds seassieskctecas aces 188 \| Balteri; Ophiure. 23624225552 -cdseseceocase 227 PEOCHSURICGS once = ane, Scenics sic eiow secs 215 | salteri, Protaster (2) 2... -ec<2.--2 sececsces 226, 227 PPTOUIST ONIN ature sso Wo aia So Soe ose ccialcisiclo wleisinin 228: |) Salter; Stenaslor...cie.co2ecaccan danse se sess 164,165 UM OIO Mc erie cia oa So Saee ns addcineecenoceeee 231 | schlotheimii, Acroura (Ophiura)............. 18 PILOT OSU can wisicis)= 2a tia.idicisie'sraps'cs sels scie eisai mis 281 | schlotheimii, Ophiura-.......----.-.-----.ne.. 18 IPEOCOOLIEV ALO wieiele coe sis: cuic visa caeociaie teed daieie 25) | sebititeri, Astropecten’ (?.))..<- <2... sccncanssee 161 PV OLODOLEUSCE 2 tee een tee ceecne 53,56 | schmidti, Aspidosoma..............-.2-sss000 244 128 CUTE) ee secant peotes 92 | schmidti, Encrinaster =. ....<:-.-.22s<iscecgsce 244 MMI TRUCE cine Soa cce cee aniee seen th eceaamaee OM | SCH CANAS TOR oe icin sw cienc.cicye:scic cannes sinigioctesivis 202 DELO ORE Re OE ee SAG! (a Stim brighuss 2: oes. =e ene aac wlsceecwsens 204 SFEFOLO DMT OL OUs tare ora ene woyercie it's mains wasvace 213 | §:\(?) Jegrandensis............----.---.--s0-% 206 proximal inframarginals..............-....-- 1406. | SG?) montanus ss <2. - ca cceecceedecceu 43,207 Mromimal radials : 524 < cceccio one ses dseccesieae TT} SeiGh) MeSPiss sens s. aces deen sess wsesecencien 206 proximal supramarginal...................-. 15)i); iS3\C2) WACDSMUTDI.. <2 o- ce onc. ove eeeccdenn 205 Pseudopalasterina ........--....2.-s226-+5 138,156 | Schoenasteride.....................-- 162, 163, 202 PR ROMIIYIS TINT ate orate ne ays cain ays Ia/ole ntaicics 156,157 | schohariz, Taeniaster..................-- 219, 220 PUNLOMASUCLE « wccccincecideocsseeis sas heise seine 235,289 | Schondorf, on revision of German starfishes. - ll RR IADICODS osc oaisioeie S eacn ie amiercisins tet 240,259 | Schuchertia. .............. 51, 140, 152, 194, 195, 252 pulchella, Urasterella............-.......- LPB TS a IAAT co Ue caw wide calcein ne Sep inenctoneeemaete 196,198 PTULCIICLUULS iE GLAST oo = = 3 on x vielen 2 ciojais'owidisiacies 178. |p SHOLGIMATa es < acte ace le eeictie s.cStewleye cc cekie's wre 196,199 DULCHEUM US, SLENASEED .. oe n ene e ewe vcewercwes L7G PWS tala tals cece cote ewcise carve denen emeeeend 195,196 IBVOMODOGIB soc co ccucccecevcccemscces 38,42, 207,208 | Schuchertiaces............0.ccececieccsessiows 163 Ipyemises,, Paleoaster...-: 225. .scccece sons stuns 26:.\ Sehucher tid sc. sats xcs car cee nw nce ste 162, 163, 194 Dyemeeus, Ataxaster. ........c2cnccccecsbeone 161 | schwerdi, Rhenaster.................-...200- 133 pyrotechnica, Palxocoma..........-.-.--+++++ 257 | secondary skeleton, see secondary plates. pyrotechnica, Rhopalocoma...............-. 254 | sedgwicki, Protaster................... 225, 226, 243 radial accessory plates................s0esc« 13. |. salary, Urastorella..< .20..1 52.02 <ccnsnss 175,188 MEMS conc nc dctiesicle co sewesenecs lec 17, 34,35,46 | shafferi, Mesopaleaster................... 44, 75,77 FACUICLOOLASLOMIOS: 3-05 < Soeccesinsiein coco svines't GA | aharrengs POleAS eT oa 0 wide wm eicjnrs se ate stawae 77 ReasTiCsde) OILS Ci) = anixaicmcwiaceicanin..ajcic ce/Sete Zar RMIT ALO Se ooo, cc o's ciciv.o oie viv'c.o sew came mnee 49,53 65 ramseyensis, Palasterina (?)........-.----- LBZ IBA le Ss POMOOlUsiecese cc coee nda es cite es scmeSoesncad 66
310 INDEX. Page. Page. simples, HOQCis 2-2. ss eo ooseeee nese aee eens 186 | stutchburii, Australaster (?)............-...- 73 CU al tae 0 aE EG pa Soe RAG OBAaSCOCCBOOOOOC 61,62 | stutchburii, Monaster.......-..-52--eseececes 73 simplex; Palzcophiuray.:...--cses- eects 235 | stutchburii, Palzaster ( Monaster)..........-.. 73 SEM PIEL, EXGENGSCEN ocac\csare ne ansea sss sent es 69) |) supramarginallac oo ccc ccs aee eee 15, 34,35, 45 skeleton, secondary, see accessory plates. Symp terurasc:s.csacssssaesceecenee sence 248, 256 sladeni, Echinasterella..................-.--- 200" Siminveriss 2 ssc cs casjssccies esteleessteneeeee 256 smythi, Petrastersass-6-sne ote tenes eee 1398 04'7;4| SyHenaths-sacccc os ecseee = 218, 222, 224, 242, 256, 267 Solasterso2.scs¢/cseccsstite cease eee eas veh 888" Leaning ter caciaiss Sees foes adh ecle iteneenes 216, 218 solids -Paleostellacancsscecatte eee e tetas 156) Dausirausec sce sccrec-oceoesseeeneceeeeees 236 sollasis Lapworthura-.csceecceceesee cee ores 951 | Tcylindricus:)2c-ccese~ee ee 216, 217, 218, 219, 220 Spaniasters-cey seco eee 39943547749"50;045 OO |) Ai ClOZADS o.oo 0 3 sien clerweinme = ain ee eee 219, 221 Silatiscutatus! S242: --acencc ssee eee seme eee 96) |) Demeafordensis=-:; - sc: esses cer seeiae-eeenenee 221 speciosa, Palzeasterind.s..+shesssiccdesesneess 1497) De SChOnarlasertes 1) saciceeclea\s-1- See ee 219, 220 speciosus Palzaster..........000eseececcecces 109) |) Dsispinosus;~ -- <-seeec-ssecn see 216, 217, 218, 219 speciosus, Potrasterse-e-ste cesses eee AT1SO STAD ek LINUOSLEN LAE cicjasc in clu in =)-eneo eee ee ee 172 speciosus, Promopalzeaster........ 1045105; 1093113") Leenttra sco. ceetce. < o-\e)sanin one eee eeeeee 216 spines, see paxille and pedicellaria. Ti CYUN GTI CON one ecee eee eee tease ee 220 spinosa. PAleOCOMGsseeeee tee ates ene eee ee 219 | tenuiradiatus, Coelaster................-...- 19 spinosissima, -Asteriagsce-ee-eecen eset anes 19 | terminals, see ocular plates. SPINOSILV SAE eee see ee eee eee 37,41 | terminology of Asteroidea...........-.. -... 13 spinosus, Echinasterias.....:.5---+.0:-2--e0- 211 | Tetraster.......... 31, 41,42, 43,50, 164, 165, 167, 212 spinosus, Teeniaster..........-..- 216,217,218,219 | T.asperrimus..........-----.2-2.0.-ceeeeeee 187 spinulosus, Palzaster.............2..22002-++ 115; | EC?) dmbricatusecc..- sess scos eee eee 168, 169 spinulosus, Promopaleeaster....... 44,104,105,115 | T.sp.ind. Nicholson and Etheridge......... 186 Spryi, Greroriuraceess saece ace een 234 | T.wyville-thomsoni (part)........--.-------+- 65 Squamaster /sce:35-22s25 cscs ee 248,949) |). US .wyville-thomsoni ....2...0. 522 scnen ee 168 SVochina tistees: cose ey ok 249 | tischbeinianum, Aspidosoma.................- 244 squamatus, Palesasters -sescce sete esse ees ee 23 | tischbeinianus, Encrinaster.................- 244 stalk of primitive starfishes................. BTS ER EIS ei) abl conesbros ssecceurenasodccacs sec 16, 48,54, 174 starfish) most primitive...225/-02---ce seen le $1, 33 | traquairi, Echinostella...........-<.-.cce0- 212 origin/ofigrasporseecesccse eee ete e eae 83) | Prematasterin<cccewsuics ss aen dessseaseee 246,247 origin of wriggling type............-.-.-- BZ i pcb) dechen ieee ele etceialaree nee 247, 248 Tadicles.sooe4 sees ceeces oe ee eee yl ed boobed (all E Spaces soqaquendoucaessancaco=cade 247 stellata, Palastering. <== .2.05.<c22esseacene 196>|) “Brentonastens. 2k 2c nose a seen epee eeae eect 195 stellata, Schuchertia.............:.0.02.06 1955 LOGO), De stellata <a. mic oe mciewne ss ooo eee sete 196 stellata; Prentonaster.2-2-es---<eesee cee ee ee 196 | Trichotaster plumiformis................... 26, 38 Stellercides.<2202s 32sec. eee 51 | Trimeraster...............-.-..- 44,45, 50, 128, 184 geological development.................- 27198) lips DALVUNUS Ce anc erelarelo = eee ee eeieentoe 134 geological distribution................... Ogi trivium: saci. ccssts base cose teceeeeeeeeee 14 ontogeny .c2s:ki cosas sete eee Stee 36 | Trochitaster, see Trichotaster. phylembry0sstes. essere ee eee 34 | typembryo of Stelleroidea.................. 85, 36 typembry0i2..ce- acc ee eee eee 85,36 | ulrichi, Urasterella........... 37,43, 45, 49, 175, 188 stellifer, Protaster (?)..............-....-- 226,228 | Uranaster......-....----/..220-.2--2-- 51,138, 154 Wlenaster (part) se seca eee 17S We elizss sf coc cee eck week eo eec meee 155 Stenaster........... 31,41, 42,48, 5068 163,168; 219) |) Ul kcinahant o.oo ooo. ce ono nieces 154,155 S22) econfluens- 223-222 2-62. ee 165,167 | Uraster hirudo...:........-...22...----cccee= 188 S33) coronella si shee ee ee 1653169) |) GiiObtususe eco. owen re eee ee eeneee 167 SNOTANGIS toss Nah oe een bs ee TSO er LOUSs sie aire oc LSee ch emisiael- Sele eS 153 Saale ts oe ase ee 189: WOruthvent oo 20.2 Sens52 eee eee wae 187 S2(?) Obtusus = .-4.5:2-s2s2ne ee ase eee 165,167 | Urasterella Stiirtz................2......-..- 163 Ss PUlchells oS oe ae sae ee 178 |) Urasterella McCoy... -2=. .<csccaecsnestaseee 40, Si salteriviessese Geer eid SP ie: Sees 164,165 41, 42,45, 47,49, 50,69, 164, 178, 194, 212 Stenasteracear: 225222502: is. ssn sees 163 | U. (?) asperrima...............----------- 175, 187 Stenasterid so: < <s2c ode eee 1625068) | (Unsasperula. <6 oc... coon a ccneseae caer 175,188 stone-canal, see madreporite. Ws?) iconstellata..<.-.sseeeecee eee eee 175,187 Streptophiurce.c.2 222-2 se este e cee eee 9155949) U> girvanensis 22. coe. eee ein 167,175,186 Stlirtzaster.se. i-th cheese ee DAB ND G2) | Wi SraNGis oa cee aerial 174,175,180 Si colvint) 620.0 o ecard ee DEF ii|| (pind. cece sokee ee cence eee 175, 188 Bicygnlpes .6 c/a. s siereiatatemre carats oe eee oe O53 )|| Wp HURL ys 2 oc cckh ssa eaeec ee ece maser 175, 182 Si marstoni 2 BAe eee 253)| UeyMOntanase cee. cachiost eee tecere eee 175,189 S167) mitchell =o. +/ccnttitncnete een eee 254} Wi MSD oe ccicisuisiaw osiene bee eel enene eeeeeene 189 SHEET 5 oi atsternlsicivin'ara'a Callao dc eae eeoes 235; 286) .U- pulchellaz.i2. 5. scmcenewnceece mash oerte 175,178 S.ibrisingoldes.. 2. <(..sa-s107. ceases one etelee 936. | Ui ruthvenl o.csoc< casas neeeeuine 174,175,187 §. lop tosomia sn cciccke cnn ce eee eee 236,287) | U.. Sel wy ic :arcirarsseraernertcteateiewierciveieteiers 175, 188 Bileptosomoldes.<. isc cicccnodacsaes somes 236,80 | Ui. Ulricht. <..11.cnniscececuseeee 37, 43,45, 49,175, 183
INDEX. 311
Page. Page.
IWrasterellaceas.s paisa tose Shien oes chee wens 163 | wykoffi, Palzaster..............2.2222-02000- 119 Wrasterellidse iy... -s2 oe sete ca sees oce 162,163,172 | wykoffi, Promopaleaster.............. 42,104,119 ventral, see actinal. wyville-thomsoni, Tetraster.....-....-...-...- 65 VENTA SHICIG cojcieeices coerce skcectetcenss 213 | wyville-thomsoni, Tetraster................- 168 vermiformis, Bdellacoma.................... 254 | Xenaster......... 40,44, 45, 46, 47, 49,50, 98,128,129 vermiformis, Palxocoma.........--...---++-- 2a Poke, CISPAl se clece akc ee ae wae emcee eer 130,181 vertebral ossicles.............. 184/213, 257,267,260.) X. ClOPANS. ack nce oanec cnc awedeoe 130,181 wachsmuthi, Schoenaster(?)..............-- LOO AX CUCROTIS 2s eae on a beeen wanwe cee eccaeecees 98 whiteavesianus, Protaster (?)............. 226,227 | X. margaritatus Follmann.................. 131 wilberanus, Mesopaleeaster (?).............. 75,84 | X. margaritatus Simonovitsch (part)...... 131, 132 ADEDETANUS 5b CLL OSCE coe wide 2 oo eee ooo a 84 | X. margaritatus Simonovitsch........ 129,130,181 wilberianus, Petraster................---- a S40 |X. (2) rhenanus. co. sec cctensaccse- cae ee ne 130,181 wilsont, Palzaster (2). ......22cecceeeeesscee LOG | oSse SUM Dleto see cccccss coal scree noi suweysieiste eS 96 wilsoni, Promopaleeaster................. 104,106 | Xenasterids...................------%- 52,53, 128 woodwardi, Eucladia.................... 276,277 | zitteli, Palzospondylus .........-.----.0.--0 262 WIISPIOS cise seis ve cow sre Saw ea neidemines 82, 33,38 ! zittell, Palastropecten..............--.....-- 262
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