‘ es Rh Ve NS Shy EY AS A SY AY A AN \ \ : : SN — WS \ AX AC SMITHSONIAN INSTITUTION UNITED STATES NATIONAL MUSEUM Bulletin 76 ASTEROIDEA OF THE NORTH PACIFIC AND ADJACENT WATERS BY WALTER KENRICK FISHER Professor of Zoology and Director of the Hopkins Marine Station of Stanford University, California PART 2. FORCIPULATA (Part) UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON 1928 One tae he e nes WA Oe Ce CRT BUTE AS The RIUITO OPLIA sti woreda: TABLE OF CONTENTS Page Foreword___------------------------- - ------------ <9 - <9 9-77-77 - 5-7-7 +--+ = -=--- 1 Systematic discussion of the fauna_-__----------------------~--~----------------------- 2 Order Forcipulata___------------------~-~-- ~~ <= 55 nnn nn nn 2 Synopsis of the known suborders and families of Forcipulata.___---.--------- AOL 3) Suborder Brisingina- ---------------------------------------------------------- 4 Family Brisingidae-------------------------------------------------------- 4 Synopsis of the genera of Brisingidae- --------_-----------~----~----------- 4 Genus Brisinga--.---------------------------------------------------- 7 (Crear IE CO ache OL NESE Ug Rea 7 Genus Brisingenés-_-_-+--=_------=-+-------=-=-------~ -=----------=---- 11 Genus Brisingella_._------------=---------------------- ---------------- 12 Genus A'strostephane._--_------------=----------------------~----~------- 19 Genus Stegnobrisinga.------------------------------------------------- 20 Genin tA stnaliriis = a ae a ee 20 Genus Freyellaster_-_--------------------------------------------------- 21 Genus Freyella._------------------------------------------------------ 24 GEE LAES Aa ss CEC ea a aa 29 Suborder Asteriadina_-_-_-.-------------------------------------------------=--- 31 Family Zoroasteridae_----------------------------------------------------- 31 GULL TOS a a a ee SOS Genus Muyxoderma.------_---___-- = -~-- 5 ~~~ = 44 Family Asteriidae____------------------------------------------------------ 56 Synopsis of the subfamilies of INSheni GAC sos ee ee ee eee ee ee 56 Subfamily Pedicellasterinae_-—_----------------------------------------- 57 Key to the known genera of Pedicellasterinae__------____-----_______- 57 GETS SEO CULE CELLOS IGT o> ee ln ee ee 58 @enus ie cranasters ee ee ee 2 See eee 67 ACTA HED a] RE er 68 Gert A TEELEES LOT ne et ene eta Seer eee ee 69 Gents CEOTCUSLET Sete ke ae rn ee ee a 75 Mees UDS PL TIE TITRE CSE a a 80 Subfamily Labidiasterinae_----------------------------------- 5 ee 88 Synopsis of the genera of Labidiasterinae-___~--~_----~-_-----------.-- 88 Genus: RUtiU Un aStet o e e e E 2 en LA ek 88 Subfamily Coscinasteriinae----~---------------------------------------- 93 Key to the known genera of Coscinasteriinae--_--_--~----_-___~.------ 94 ARATE SEER EET CL ee er ee 96 Genus dsntolastentas ooh ee ee eee ae ee Se 102 Genus sSclenasterzas 2 8 aan en oe Se et ee ee 8 105 rer TIS EAB ENOTLEERS ee ti a cod eh a a a ha nn ae at 118 EEG OO SERTATESTET TCLS ae ee ee eet on ee ro eee oo 128 Subeenvs Ooscmusienias: === ea ee ee eee 128 Sra EELS OS LOU CG SLE TT C0 129 RUN T UAT URGSIET EAS Soe ee ee ree Bee. Sea 129 GRIN ESPANOL Lee a tn pre a an ee ee ae 130 Gra ere era eS 130 GGrHPAG IE Ta TaSten ee ee a ee cee ee eee Se 131 GenIRSTCHHDAIEnIS te een ee Lee EE eee ee 131 CSV TT BILE ONO we 139 Subfamily Pycnopodiinae---------------------------------------------- 148 GGUS pees O RY TL ea a ee ere a a ee a 148 (Genvisyeyen0n ON Ome ee a ne 153 Explanation of plates--_---------------------------------------------------------- 162 Tndex. =. seo a ea a nn nn ne en nn nnn we 243 vet epalee ocr Tie é aman ena tp Rear ODOT 8S ha “eey \ Seba? {oman eee fete ey mA : gb: ee eae: PRELSOALERE a2Ri yas an ‘ Miia B Bitoh a0 hme) Pea oma 2 SERBS IRS REE = 97 ee AMR EOGOOW 7 hn eis raaG Sk, aug ASTEROIDEA OF THE NORTH PACIFIC AND ADJACENT WATERS By Watter Kenrick FIsHER Professor of Zoology and Director of the Hopkins Marine Station of Stanford University, California PART 2. FORCIPULATA (Part) FOREWORD Part 1 of this work, comprising the Phanerozonia and Spinulosa, was issued on June 30,1911. The present part contains an account of the families Brisingidae, Zoroasteridae, and four subfamilies of the Asteriidae—the Pedicellasterinae, Labidi- asterinae, Coscinasteriinae, and Pycnopodiinae. The remainder of the Forcipulata will be described in the final installment, the manuscript of which is completed. Material for study has been derived from the sources which were indicated in Part 1 (p. 1). In addition I have gone over the British Museum collection; some of the types in the Muséum d’Histoire Naturelle at Paris; the collection of the Peabody Museum, Yale University (including a part of Verrill’s material); and all of the collection of the United States National Museum. Through the kindness of Dr. T. Odhner, of the Riksmuseum, Stockholm, I received a small collection from the Vega Expedition as well as miscellaneous Arctic specimens for comparison. The Victoria Memorial Museum (now the National Museum of Canada), Ottawa, forwarded certain of Verrill’s types. Dr. Th. Mortensen loaned cotypes of Asterias amurensis and an authentic example of Leptasterias ochotensis. Dr. Jules Richard, of the Musée Océanographique at Monaco, loaned a cotype of Sclerasterias guernei. Dr. H. L. Clark loaned a considerable amount of material from the rich collection of the Museum of Comparative Zoédlogy and, with great patience, has allowed me to dissect many of the Asteriide in his care; while Mr. Austin H. Clark has been equally liberal with material from the National Collection. Prof. Wesley R. Coe has aided me in my study of Verrill’s types at the Peabody Museum and in the search for those which are missing. I have been greatly indebted to Dr. R. Kirkpatrick, of the British Museum, for a number of photographs, notes on types, and for the loan of specimens prior to a special trip which I made in 1923 to the British Museum. Dr. C. McLean Fraser, formerly director of the Canadian Biological Station, Nanaimo, British Columbie, has contributed specimens and aided my search for others at Departure Bay, British Columbia. The California Academy of Sciences has financed consid- erable collecting in the region of Puget Sound and in Lower California. The material is credited in the lists of specimens. My thanks are due to several friends who have collected for me in different localities, namely: Mr. Philip Baxter, Dr. J. C. Brown, 1 2 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Dr. C. H. Gilbert, Dr. H. Heath, Dr. Carl Hubbs, Dr. G. Dallas Hanna, Mr. HC: McMillin, Dr. Charles H. O’Donoghue, Mrs. Ida S. Oldroyd, Mr. E. F. Ricketts, Mr. S. P. Smith, Prof. J. O. Snyder, Prof. E. C. Starks, Dr. F. W. Weymouth, and Mr. George Willetts. After completion of part 1, work on the collections was discontinued in order to allow for the publication of Verrill’s “Shallow-water Starfishes,’’! which was delayed until 1914. In the meantime I had undertaken a report on the very extensive col- lection of sea stars made by the Albatross in the East Indies from 1907 to 1910. Work on the north Pacific collections was resumed in 1918, but other duties have interfered with the completion of the manuscript, of which this installment is about one-half. It is hoped, however, that the results have been improved by a ripening process and may therefore be of more permanent value. Additions to the bibliographic list will be deferred to part 3. References have been made sufficiently full to obviate any inconvenience from this omission. The photographic figures were made in the photographic laboratory of the United States National Museum. The drawings are by the writer. SYSTEMATIC DISCUSSION OF THE FAUNA Class ASTEROIDEA Burmeister’ Order FORCIPULATA Perrier Stelleridae Forcipulatae Purrizr, Mém. fitoiles de Mer, 1884, p. 167. Forcipulata Perrier Expéd. sci. Travailleur et Talisman, 1894, p. 27. Cryptozonia (part) SuavEN, Challenger Asteroidea, 1889, p. 397. Forcipulosa VERRILL, Shallow-water Starfishes, etc., 1914, p. 24. Differing from all other orders of Asteroidea chiefly in the presence of crossed (forcipiform) and straight (forficiform) pedicellariae, or of either alone. Form always stellate, the rays, five to many, frequently slender and long. Abactinal skeleton when present formed of skeletal arches (transverse on rays), either independent or bound together by intermediate plates, forming a network with rectangular or very irregu- lar meshes. The skeletal arches usually correspond to every other or to every third adambulacral and are composed of pieces exactly or approximately corresponding in the ventral, lateral, and dorsal regions of ray. In most cases the plates also form more or less definite longiseries, among which the actinal (when present) and marginal are almost always regular, the carinal usually regular, and the dorsolaterals usually irregular; marginal plates usually not greatly larger than abactinal, sometimes partly or wholly suppressed, especially when abactinal skeleton is imperfect; latter some- times absent. Ambulacral ossicles frequently short and crowded, compressing the primitively double series of tube-feet (always with suckers) into two zigzag, four, or even six longiseries; adambulacral plates generally short and crowded (except Bris- ingidae) equal in number to the ambulacrals; mouth plates frequently inconspicuous 1 Monograph of the Shallow-water Starfishes of the North Pacific Coast from the Arctic Ocean to California. Smithson. ian Institution. Harriman Alaska Series, vol. 14, 1914. This work is referred to in this report as ‘‘Shallow-water Starfishes, 1914.” 2 Key to the orders of Asteroidea, see part 1, p. 16. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 3 and sunken in actinostome but primitively strong and spiny, as in the Brisingidae, Labidiasterinae, and most Pedicellasterinae. Papulae few to many, frequently in clusters, usually on all surfaces, in adult. Spines vary in form from coarse granules to long delicate needles. SYNOPSIS OF THE KNOWN SUBORDERS AND FAMILIES OF FORCIPULATA a'. Ambulacral ossicles not compressed; upper end of ossicle sub-cylindrical or hour-glass-shaped, the pair closely joined by a muscular symphysis; consecutive pairs articulated end to end without overlapping and resembling centra of a vertebral column; ambulacral pores large, biserial; adambulacral ossicles stout, cylindrical, or hour-glass-shaped; odontophore super- ficially visible on margin of small circular disk, as an “‘interradial” plate; papule often Jacking pusee p- Sih elses, - Uaiee ibe cet le Suborder Bristnaina Fisher, new. Deep-water Forcipulata with characteristic small circular disk, slender, often deciduous rays, sharply differentiated from disk, and long, delicate, sacculate, acicular marginal and adambulacral spines; dorsal skeleton weak, that of ray variable, never reticulate, confined to proximal third or half of ray, composed of transverse, independent parallel ridges or costae, separated by areas of integument without plates; or the intervals may be partly or completely filled with more or less perfectly developed plates immersed in the body wall; or the arches may be absent and a tessellation of these plates may cover the genital region of ray; or there may be thin plates, more or less spiniferous, together with differentiated transverse costae; straight pedicellariae absent; crossed, abundant; gonads two to many attached to lateral integument of basal portion of ray; actino- stome relatively large, peristome broad; mouth plates expanded, usually with promi- Nent spines 4seye es ee Ss | Pas werd ee ee Tes ooh ise, eh eked Ser Brisingidae Sars. a?, Ambulacral ossicles compressed, the upper ends short, often imbricated (not subcylindrical and centriform); adambulacral plates short, compressed; odontophore entirely hidden, never exposed on margin of disk; papulae never lacking in adult; marginal plates normally well developed; abactinal skeleton normally of lobed plates imbricated in series or linked by intermediate plates into a regular or irregular reticulum. Suborder AsTERIADINA Fisher, new. bl. Only straight pedicellariae present; deep-water species with very small disk and normally five, slender, usually subterete rays, the plates of which are arranged in regular, usually closely juxtaposed, longiseries; alternate adambulacral plates (in one genus, all) with a prominent spiniferous projection into furrow____---------------- Zoroasteridae Sladen. b?, Straight and crossed pedicellariae; abactinal skeleton normally a regular or irregular reticulum; adambulacral plates without a prominent spiniferous projection into furrow; rays five to many and disk variable; shore to moderate depths. c!, Ccelom of disk separated from that of ray (except for a small dorsal passage) by a contin- uous oblique or horizontal shelf or discobrachial wall,? which extends from the acti- nostomial ring to the dorsal surface of disk, fusing with the inner edges of the inter- radial septa which it covers; the inner edge of the shelf passes over the upper end of the second pair of ambulacral ossicles and just external to outer border of odontophore so that the ambulacral ridge (distad to the first plate) can not be seen from ceelom of disk; ventrally, ccelom of ray ends in a shallow cul-de-sac near inner end of ambulacral ridge where in Asteriidae the ecelom of disk communicates with that of ray. Rays numerous, disk large; bases of rays fused for a variable, but considerable, distance, the juxtaposed sides forming the so-called double interradial septum; skeleton reticulate, robust. West Coast of Mexico, Central, and south America_-__-Heliasteridae Viguier. " 1 First described by Clark, The Starfishes of the Genus Heliaster, Bull. Mus. Comp. Zodl., vol. 51, No. 2, 1907, p. 67, pl. 6, 4 BULLETIN 76, UNITED STATES NATIONAL MUSEUM @. No discobrachial septum separating disk and ray coelom as in Heliasteridae; rays 5 to 45, but usually 5 or 6; skeleton of rays, aside from ambulacral and adambulacral plates, consists of 5 primary longiseries of ossicles—1 carinal, 2 superomarginal, 2 inferomarginal, to which is generally added 2++ dorsolateral, 2+ actinal, and rarely 2 intermarginal; dorsal skeleton generally elaborated into a reticulate structure with or without secondary intermediate ossicles; ambulacral ossicles usually crowded; tube-feet in 2 or 4 (occa- sionally more) longiseries- - ------------------------------- Family Asteriidae Gray. Suborder BRISINGINA Fisher Family BRISINGIDAE G. O. Sars Archaic deep-sea Forcipulata with small, circular disk, numerous, slender, sharply differentiated, often deciduous rays, and long, delicate, sacculate, acicular marginal and adambulacral spines; ambulacral plates massive, uncrowded, the dorsal articulating region centrum-like, nonimbricating; adambulacrals usually elon- gate, hour-glass-shaped; dorsal skeleton weak, that of rays variable, never reticu- late, confined to proximal third or half of ray, composed of transverse, independent, parallel ridges or costae, separated by areas of integument without plates; or the intervals may be partly or completely filled in with more or less imperfectly developed plates immersed in the body wall; or the arches may be absent and a tessellation of thin plates may cover the genital region of the ray; or there may be thin plates more or less spiniferous together with differentiated transverse costae; straight pedicel- lariae absent; crossed, abundant; gonads, two to many, attached to lateral integument of basal portion of ray; typically a series of spaced solitary long marginal spines and one to several similar shorter subambulacral spines incased in a sacculus covered with tiny crossed pedicellariae; actinostome relatively large, peristome broad; mouth plates expanded, usually with prominent spines. SYNOPSIS OF THE GENERA OF BRISINGIDAB a. Abactinal surface of disk and genital region of ray provided with numerous conspicuous papule; two gonads to each ray; mouth plates broad and fan-shaped toward the actinostome, nearly closing entrance to ambulacral furrow; genital region of ray with transverse skeletal arches, between which the integument is strengthened by immersed plates and pierced by papular pores; ray with regularly spaced lateral, transverse combs of upward of seven conspicuous, slender spines; adambulacral plates higher than long, with a single, promi- nent subambulacral spine frequently truncate and more or less spatulate on proximal part of ray; first three to five pairs of adambulacral plates united in each interradius, and above them the marginal plates similarly united; a syzygy between first and second adambulacral plates, and also sometimes a partial syzygy between the second and third and between the third and fourth plates. Genotype Brisinga semicoronata Perrier_-__-__-_-- Odinia Perrier. a*. A single circle of rather small papulae near margin of disk, two papulae corresponding to each ray; rays, as in Brisinga, without papulae. First and second adambulacral plates united by a syzygy (nonmuscular symphysis) and upper part of second and third ambulacral plates united by syzygy; gonads numerous, in series; first pair of adambulacral plates and first pair of marginal plates in each interbrachium closely united. Genotype Brisinga mimica anal Sees ORES SSI a ale EE rl eo gps etd ae Dito Brisingenes Fisher. a’. No papulae present either on disk or on rays; abactinal skeleton present on disk and on proximal portion of rays, at least, either in the form of transverse independent skeletal arches or as a continuous covering of thin plates, or both arches and intervening thin plates. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 5 b!. Disk plates large, with one to three fairly large acicular spines; a vertical series of about four conspicuous, lateral spines to each successive skeletal arch of the rays (of which there are 9 or 10 well-spaced complete ones, confined to basal fourth of ray), these lateral combs occurring at regular intervals all along side of ray; integument between costae has spaced embryonic platelets of various sizes and irregular outline, invisible until dry; adambulacral plates short without furrow spinelets; subambulacral spine with a modified, capitate, truncate tip throughout costal region; syzygy between first and second adambulacral plates; first pair of adambulacral plates and sometimes most of second pair united interradially ; in young specimens the united pair of conspicuous first marginals normally above the first pair of adambulacrals, may drop between the distal ends of latter, as normally in Brisinga; mouth plates expanded fanwise toward actinostome, nearly closing entrance to ambulacral furrow; gonads in a series of eight or nine, proxi- mally, just above adambulacral plates; related to Odinia. Genotype Brisingaster robillardi de Loriol_ ---------------------------------------- Brisingaster de Loriol.‘ b?. Disk plates small, bearing one to several small spinelets; on the ray only one lateral or marginal spine corresponding to the variably spaced inferomarginal plates; never a vertical comb of conspicuous lateral spines. cl. First and second adambulacral plates as well as the upper part of the second and third ambulacral plates united by syzygy (nonmuscular symphysis). d. Abactinal skeleton of rays in the form of independent, spaced arches or costae composed of elongate, more or less compressed, overlapping plates, projecting well above the level of the intervening integument and bearing small spinelets; intercostal integu- ment not fortified by thin, immersed, spineless, fenestrated plates. e!. Gonads numerous, in a series along either side of each ray; at least the first pair of adambulacral plates is joined by their lateral faces, and above them is a united. pair of first marginal plates—four in all. f'. Subambulacral spines of proximal adambulacral plates slender, acicular; the acces- sory subambulacral spine, if present, is on the adoral half of the plate; adambu- lacral armature is not dense and crowded. Genotype Brisinga endecacnemos Asbjgrnsen.----------------------------------------- Brisinga Asbjgrnsen f?. Subambulacral spines of proximal adambulacral plates with modified, capitate, often truncate, tips; second subambulacral spine regularly present, prominent, and near aboral end of plate; adambulacral plates short, with crowded armature; second and third pairs of adambulacral plates sometimes united interradially. Genotype Brisinga panopla Fisher - - ------------------ Craterobrisinga Fisher é. Gonads two to each ray (one on each side); subambulacral spines all delicate and acicular. f'. The interradial (first) pair of adambulacral plates is joined by their lateral faces, and above them, a united pair of first marginal plates—four in all. Genotype Brisinga moluccana Fisher---------------------------- Astrostephane Fisher. f?. The interradial (first) pair of adambulacral plates is not joined, but separate, the outer end of the combined mouth plates usually interpolated between the inner ends of these adambulacral plates; first pair of marginal plates not closely united by their lateral faces, but only by the adoral ends, to which also is closely united the lower end of the interradial plate, forming a rude inverted Y, of which the angle is the apex of the interbrachial angle and the arms are the first marginal plates; adambulacral plates slender with delicate subambulacral spine; rays delicate, very deciduous. Genotype, Brisinga fragilis Fisher. Brisingella Fisher. 41 have examined specimens in the British Museum since my first keys were published (Ann. and Mag. Hist., ser. 8, yol. 20, 1917, p. 419; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 502). 6 BULLETIN 76, UNITED STATES NATIONAL MUSEUM d@, Abactinal skeleton of rays consisting of independent, compressed arches or costae, as in Brisinga, but the integument between the arches is crowded with numerous spine- less, immersed, fenestrated, thin plates which touch or slightly overlap, and leave the integument entirely flexible; gonads two or four to each ray. é'. First pair of adambulacral plates united, and joined to their upper side is a united pair of marginal plates, four in all, as in Brisinga; proximal adambulacral plates higher than long; gonads two to each ray. Genotype Brisinga (Stegnobrisinga) placoderma Fisher-------------+----------------------- Stegnobrisinga Fisher. é. First pair of adambulacral plates not joined together by their lateral faces, but separate; first pair of marginal plates is not united by their lateral faces but only by the adoral ends, to which also is closely united the lower end of the interradial plate, forming a rude inverted Y, of which the angle is the apex of the interbrachial angle and the arms are the first marginal plates; proximal adambulacral plates not higher than long; gonads two or four to eachray. Genotype, Brisinga panamensis hud wigiees= 222 se ee as Tee SSS ee ee ee Astrolirus Fisher. @. Abactinal skeleton of genital region of ray composed of a uniform armor of thin, spin- iferous, more or less overlapping plates, but not of independent arches or costae. é. Primary plates of disk much larger than the others which are small; gonads two to each ray; an interradial plate, vertical in position, is interpolated between the proximal ends of the first adambulacral plates, and touches the mouth plate, but does not encroach upon the actinal surface as in Colpaster. Genotype Belgicella TACOUU ZOMG LAG Wi Bee ee eat ae ee Belgicella Ludwig. é. Primary plates of disk not conspicuous, and not distinguishable from the other abac- tinal plates of disk. fi. An azygous interradial plate, shield-shaped and conspicuous superficially on the actinal surface, separates the first pair of free adambulacral plates; gonads unknown. Genotype, Colpaster scutigerulus Sladen__--_------ Colpaster Sladen. f?. First pair of adambulacral plates not separated by an azygous plate but united as in Brisinga, and above them is a pair of conspicuous, united, first marginal plates— four in all in each interradial angle; gonads numerous, in a series along either side of the ray. Genotype Freyella fecunda Fisher__-_---- Freyellaster Fisher. c. No syzygy, or nonmuscular symphysis, between the first and second adambulacral plates nor between the upper part of the second and third ambulacral plates, but a normal 5 muscular symphysis not different from the others; no marginal plates directly above the first pair of adambulacral plates; the latter are not united except sometimes by the proximal ends; touching the lower end of the interradial plate is a pair of very inconspic- uous plates lying in the same plane, and superficially appearing to be a part of the inter- radial plate.’ These are really the outer ends of the mouth plates which project dorsally behind the first pair of adambulacral plates. The latter, by sometimes touching at their inner ends or apposing their lateral faces, segregate this dorsal portion of the mouth plates from the actinal, spine-bearing part. For this reason they may easily be mis- taken for two entirely independent plates. d', Abactinal skeleton of ray composed of a uniform armor of thin, spiniferous, more or less overlapping plates, as in Freyellaster, not of spaced independent arches or costae; furrow spinelets not modified or expanded at the tip. Genotype, Freyella spinosa PROPTLOT Saree Pe Se ERE Eos eh ey ee ea at Ale t F Oe Freyella Perrier. d@. Abactinal skeleton of ray composed of independent transverse arches, composed, on radial area, of flattened overlapping plates (not of elongate, narrow, more or less com- pressed ossicles as in Brisinga) ; these costae bear spinelets and are separated by inter- vals devoid of plates; furrow spinlets with curiously modified expanded tips. Genotype, Astrocles actinodetus VWisher___-_.__-_____--_____ 22 _- Astrocles Fisher. 6 The interradial plate described by Ludwig in Relgicella is very probably the true interradial plate plus these extreme outer ends of the mouth plates, which, unless treated with potash, appear to be a part of the interradial plate. (Ludwig, 1903, p. 60.) ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 7 a. No papulae present either on disk or on rays; no visible abactinal skeleton on rays but embryonic plates may be concealed in the thin integument; gonads unknown. b!. Minute embryonic lattice plates are present in abactinal integument of ray; functional skeleton of ray reduced to ambulacral and adambulacral plates; disk finely spinulate, a few spine- lets extending upon ray; interbrachial skeleton resembling that of Brisingella, but the first marginals unequal in size; first adambulacral plates entirely separated; adambulacral armature very simple. Genotype, Hymenodiscus agassizi Perrier__Hymenodiscus Perrier.® b?. Rays composed of ambulacral and adambulacral plates, and an abactinal integument devoid of skeleton, but covered with numerous, relatively large pedicellariae arranged in trans- verse bands. Disk not known. Genotype, Gymnobrisinga sarsii Studer__Gymnobrisinga Studer.® Genus BRISINGA Asbjgrnsen Brisinga ASBIGRNSEN, Fauna Litt. Norvegiae, 1856, andet hefte, p.95. Type, B. endecacne- mos Asbjgrnsen.—FisuEer, Annals and Mag. Nat. Hist., ser. 8, vol. 20, 1917, pp. 421, 426; Bull. U. S. Nat. Mus., 100, vol. 3, 1919, p. 509. Diagnosis —Brisingidae without papulae; with the abactinal skeleton of rays in the form of transverse independent arches separated by intervals lacking plates (except sometimes microscopic plates carrying minute prickles); with numerous gonads forming a series along either side of each ray; with a syzygy or nonmuscular symphysis between the first and second adambulacral plates, and between the upper end of the second and third ambulacral plates; with a united pair of first adambulacral plates, and first marginal plates in each interbrachial angle—four plates in all; with the subambulacral spines of proximal plates acicular, unmodified; accessory subam- bulacral spine if present on adoral half of plate. Remarks.—In B. trachydisca Fisher the distal ends of the first or united pair of adambulacral plates of each interradius are wedged apart by the united first marginal plates—or rather appear to be. In Sars’s admirable monograph of Brisinga coronata, two figures of B. endecacnemos (Sars, 1875, pl. 8, figs. 8 and 9) show that the first adambulacral plates are not joined so closely as in Brisingenes, Astrostephane, or Stegnobrisinga. But the structure of these interradially situated adambulacrals and marginals is quite different from that of the same plates of Brisingella, as may be readily determined by examining Plate 4, Figures 4 and 6, of the same work. These figures show the structure of the plates in Brisingella coronata (G. O. Sars). No species of Brisinga are known to occur in the North Pacific region. Genus CRATEROBRISINGA Fisher Craterobrisinga FisHEeR (subgenus), New Hast Indian Starfishes, Proc. Biol. Soc., Washington, vol. 29, p. 33, Feb. 24, 1916. Type, Brisinga panopla Fisher; Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, pp. 421, 426; Bull. U. S. Nat. Mus., 100, vol. 3, 1919, p. 512. Diagnosis.—Differing from typical Brisinga (which it resembles in appearance and in the possession of serial gonads and of closely apposed first adambulacral and first marginal plates of adjacent rays) in having proximally two subambulacral spines of conspicuous size, the larger of which (and also sometimes the smaller) has an enlarged, modified, capitate, often truncate tip. Costae usually numerous, and genital region extended; first adambulacral plate, and sometimes the first 2.5, joined ¢ See Fisher, Bull. U.S. Nat. Mus. 100, vol, 3, 1919, p. 502, footnote; Ann. and Mag. Nat. Hist., ser. 9, vol. 2, 1918, p. 104 (fig.), 8 BULLETIN 76, UNITED STATES NATIONAL MUSEUM to corresponding plate or plates of the adjacent ray, or if rays are less than 10, the joined pair of first marginal plates may be more or less interpolated between the distal ends of the first adambulacrals. But the first adambulacral plates of adjacent rays are never separated to their proximal ends, so that the mouth plates form the apex of the interradial angle as in Brisingella. No matter what the number of rays may be, the first pair of marginal plates is closely apposed for the whole length of the plate, and, as stated above, their lower sides may be squeezed in between the outer ends of the first or interradial pair of adambulacral plates. When there are fewer than 10 rays these plates descend and separate the outer ends of the normally united pair of adambulacrals in such a way that the marginals can be seen from below. This seems to be a means of strengthening the actinostomial rmg. A non- muscular symphysis or syzygy between the first and second adambulacral plates, and between the dorsal end of the second and third ambulacral ossicles. Adam- bulacral plates short, with a crowded, characteristic armature consisting of an aboral, obliquely transverse series of two subambulacral spines and one or two furrow spine- lets, and usually also one adoral spinelet. The lateral spines and the major adam- bulacral spines are typically long and bristling. Mouth plates small, with one to three suboral spines. Remarks.—This genus is not so sharply differentiated as Brisingella and Steg- nobrisinga, but is readily to be recognized by the crowded adambulacral armature and the curiously modified, capitate, proximal subambulacral spines, which are similar to those of Brisingaster de Loriol. The species to be included in this group are: Craterobrisinga panopla (Fisher), C. parallela (Keehler), C. alberti (Fisher), C. cricophora (Sladen), C. eucoryne Fisher, C. analoga Fisher, C. variispina (Ludwig), C. multicostata (Verrill), and probably also the aberrant O. evermanni (Fisher). In this species the proximal subambulacral spines are longer and slenderer than is usual in Craterobrisinga, and the modified tip is not so heavy as in typical species, nor is the adambulacral armature so crowded. The second subambulacral spine is frequently quite small and easily mistaken for an aboral furrow spinelet, but on certain plates, without any regularity that I can discover, this inner subambulacral becomes nearly as large as the outer. On such plates there is usually also.an aboral furrow spinelet, making three in an oblique transverse series, with the lateral spine additional, if such happens to be present. These enlarged inner subambulacral spines are present on the outer part of the costal region and beyond, and are not shown in the figures of the adambulacral plates given by me in connection with the original description. (Fisher, 1906, pl. 48, figs. 2, 2a.) In these figures only the dwarfed inner subambulacral spines are shown. The adoral spinelet appears never to be present. CRATEROBRISINGA SYNAPTOMA Fisher Plate 1; Plate 6; Plate 7, Figure 3; Plate 12, Figure 3 Craterobrisinga synaptoma Fisumr, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 426. Diagnosis.—Rays 12, 14, and 15, with very long genital area crossed by 35 to 40 irregular, fairly well-spaced, complete and incomplete prominent spiniferous costae; genital region equal to about 8.5 to 10 r, or 0.6 total length of ray; disk with promi- nent spinelets, solitary except on primary radial plates, about 1 mm. long; no disk ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 9 pedicellariae; adambulacral plates short and broad, with proximally usually two aboral furrow spinelets and two subambulacral spines all in a transverse series, and sometimes also a furrow spinelet on the proximal half of plate; first 10 or 12 outer subambulacral spines with circular, enlarged, sharply truncate tip; mouth plates decidedly small, with two or three actinostomial spinelets, and on the outer part of plate a transverse series consisting of one or two adoral furrow spinelets and one taper- ing suboral spine; first 2 or 2.5 adambulacral plates of each ray fused to those of adjacent ray by a nonmuscular articulation. R 220+ mm., r 15 mm. (14 rays); R 245 mm., r 13 mm. (12 rays). Description —Disk fairly large and elevated above base of rays as a rule, the margin being rounded. Abactinal surface plane, covered with terete, papilliform, blunt, uniform, skin-covered spinelets which are sharp when dried, and spaced about 0.5 mm. apart. The calcareous part of the spinelet is quite slender, about 1 mm. long, and the tip is provided with numberous microscopic points. The abactinal plates of the disk are subcircular with irregular margin and the spinelets are ordinarily one to a plate, although a few plates near the border have two to six spinelets in one or tworows. There are no pedicellariae among the spinelets. In among the ordinary plates are small irregular spineless plates, one-fourth to one-half the diameter of the primary plates. The larger plates with several spinelets probably represent the primary apical plates. Genital region of ray very long, equal to 8.5 to 10 r, or on the only complete ray of an adult specimen about 0.6 the length of the ray. The costae are somewhat irregular in spacing and form. Ordinarily they are opposite alternate (short) adambulacral plates with intervals where they correspond to two or three consecutive adambulacral plates. The arches are typically brisingoid in being composed of compressed plates so that they form an elevated ridge, which is ordinarily sinuous on the mid-dorsal region, and frequently incomplete in the mid- dorsal region as that part of the arch may be suppressed. Sometimes the arches branch and join the adjacent arches. At the base of the ray the ridges vary greatly on different rays of the same specimen, there sometimes being only disconnected plates. These are present, more or less, on the dorsal region when the arches are incomplete. The costae and independent plates bear a single series of conspicuous spinelets, 0.75 to 1.25 mm. long, and numerous slender pedicellariae. There are 35 to 40 complete and incomplete arches reaching 0.6 to 0.7 the length of rays or 8 to 10 r from base of ray. Lateral spines long, except the first few; first spine at upper border of fifth or sixth adambulacral plate. The succeeding spines increase rapidly in length; about 4 r from base they are five adambulacral plates, or 10 to 11 mm., in length, and very slender. Adambulacral plates shorter than broad at base of ray, and only slightly longer than broad throughout the remainder of genital region. Armature consists of a transverse series, along the aboral margin of the plate, of two spinelets and two spines, or beyond the base of the ray, one spinelet and two spines. The spinelets are about as long as the plate, or a little longer, and are directed into the furrow. They are incased in a loose sacculus bearing small pedicellariae. The outer of the two large subambulacral spines is heavier than the inner and the first 10 or 12 are shorter 10 BULLETIN 76, UNITED STATES NATIONAL MUSEUM and heavier than the succeeding ones, and bear a subcircular, flaring truncate clavi- form tip. The tip appears as if sharply cut off with a knife and is provided with numerous sharp points. The end of the spines narrow as the spine lengthens. The fifth spine from base of ray is about as long as three consecutive plates and the tenth about as long as four; succeeding spines reach a length of 4.5 to 5 plates in length. The inner subambulacral is somewhat shorter, slenderer, and usually is only slightly thickened at the tip on the proximal plates. But in the cotype on two of the rays some of the proximal plates have the second or inner subambulacral spine nearly or quite as large as the outer, and have only one aboral furrow spinule. (See pl. 1, fig. 3b.) On the distal plates there is but one (distal) furrow spinelet. Some plates have a spinelet just adorad of the middle and directed into the furrow, or about mid- way between the middle and the adoral margin of the plate. There does not seem to be any regularity in the presence of this spinelet which is about the length of the shorter of the two aboral furrow spinelets. The sheaths covering the adambulacral spines are closely covered with minute pedicellariae. The joint between the first and second adambulacral plates is nonmuscular, the transverse edges of the two plates being fitted tightly together. The ray breaks off at this pot. The first two adambulacrals of any ray are fused by their lateral faces with the corresponding two of the adjacent ray by a nonmuscular joint. The first two lateral or marginal plates are similarly joined. There is a continuous series of marginal plates from the interbrachial angle to the first spiniferous marginal (about 15 plates). The articulation surface of the second pair of ambulacral ossicles (distal face) where a ray has been broken from disk is rather high and narrow and broader above than below. (See pl. 1, fig. 1.) This articulation surface is one side of a nonmuscular or syzygial joint. Mouth plates small, joined to first adambulacrals by a muscular joint; acti- mostomial margin rather short. Armature: on the actinostomial margin three, or two, spinelets; the outer slightly longer than the innermost; near the aboral margin of each plate, a transverse series consisting of one or two furrow spinelets, and a tapering, pointed, suboral spine as long as the first three adambulacral plates. All the spines and spinelets bear pedicellariae. Madreporice body prominent, about its own diameter from the margin of disk. Gonads very numerous, serially arranged along the genital stolon. The ovaries are spherical bodies, the largest about 3 mm. in diameter. Numerous smaller ovaries are crowded among the larger, and they all decrease in size on the outer half of the long genital region. The testes are also numerous, and each is a many-lobed body, the series extending to the end of the genital region. The surface of the ambu- lacral plates facing the coelom is roughened by many little points or thornlets, which in the male seem to be, in some cases at least, ossifications between the crowded lobes of the gonads where these press against the ambulacralia. Type.—Cat. No. E. 1413, U.S.N.M. Type-locality.—Station 3342, off British Columbia, 52° 39’ 30’’ N., 132° 38’ W., 1, 588 fathoms, gray ooze, coarse stones; bottom temperature, 35.3; four specimens. Distribution.—Known only from the type-locality. Remarks.— Craterobrisinga synaptoma is a very distinct species, so far as the pres- ent knowledge of this group of forms allows one to judge. It is the only species ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 11 known from the Pacific coast of America. Its nearest known relatives are C.variispina (Ludwig), 807 fathoms, off the Paumotu Islands; C. panopla and C. alberti (Fisher), from the Hawaiian Islands; and (. cricophora (Sladen), from off St. Thomas, Virgin Islands, 390 fathoms. It resembles also in a general way the other species noted in the remarks under the generic diagnosis, namely C. encoryne and C. analoga Fisher, and (. parallela (Koehler). Craterobrisinga synaptoma is characterized by the very long genital region and the numerous, irregular, uncrowded costae. . alberti has a long costal region but it has a small disk, only nine rays, shorter abactinal spinelets, more regular and fewer costae, longer lateral and subambulacral spines, intercostal integumentary prickles, and especially a characteristic arrangement of the first adambulacral plate of adjacent rays. These, instead of being joined as in species with more numerous rays, are separated by the lower ends of the conspicuous first marginal plates. This seems to be a necessary arrangement to complete the circle of plates bounding the actinostome in those forms with fewer than 10 rays. In C. synaptoma the first two adambulacrals of each ray are joined to the corresponding plates of the adjacent ray, and the first marginal plates are smaller and entirely obscured from below by these proximal adambulacrals. In @. panopla the adambulacral plates are shorter and higher as seen from the side of the ray, than in synaptoma, the costal region is shorter, the costae are complete, more regular, and closer together, and their spinelets conspicuously shorter. The costae are more often opposite every adambulacral than opposite alternate adambula- eral plates. It is characteristic of panopla that the lateral and subambulacral spines are long and rigid, while in synaptoma they are not, and the lateral spines are more closely placed owing to the more frequent annular costae. In panopla the disk is provided with two sizes of pedicellariae; in synaptoma there are none. In C. variispina the costae are close together. There is a complete arch opposite each adambulacral and in the interval a nearly complete ridge, which does not fuse with an adambulacral. The arches and secondary ridges are quite regular and the narrow strips of intervening integument bear small spinelets. Moreover, the genital region is relatively short. Genus BRISINGENES Fisher Brisingenes FisHer, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 427. Type, Brisinga mimica Fisher; Bull. U. 8. Nat. Mus., 100, vol. 3, 1919, p., 517. Diagnosis.—Closely similar in appearance to typical Brisinga but differing in hay- ing on the margin of disk directly over the first pair of enlarged ambulacral plates of each ray a pair of papulae. There is thus a circle of these papulae, twice as numerous as the number of rays, and the papulae of each pair are separated slightly less than the space between the pairs. Gonads numerous, in close series on either side of each ray; first adambulacral plate and first marginal plate joined for their whole length to the respective plates of adjacent ray; thus there are four closely joined plates in each interradius; a nonmuscular symphysis, or syzygy, between first and second adambulacral plates and between the dorsal part of the second and third ambulacral plates, as in Brisinga. 12 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Remarks.—Brisingenes mimica and B. anchista of Buton Strait, Celebes (Fisher, 1919, pp. 518, 521), are in most respects closely similar to Brisinga, s. s., except for the regular circle of papulae near the margin of the disk, there being two papulae for each radius. The first pair of adambulacral plates is more closely joined than in true Brisinga judging by the figure of B. endacnemos Asbjgrnsen given by G. O. Sars (1875, pl. 7, figs. 8 and 9) and the condition of these plates in B. trachydisca. The outer ends of the plates tend to radiate apart somewhat, and in the latter species the united first pair of marginals slips down between them. No member of this genus is known from the north Pacific. Genus BRISINGELLA Fisher Brisingella Fisner, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, p. 427. Type, Brisinga fragilis Fisher; Bull. U. S. Nat. Mus., 100, vol. 3, 1919, p. 523. Diagnosis.—Differing from typical Brisinga in having only one gonad on either side of each ray; in having the first adambulacral plate separated from that of the adjacent ray by the outer ends of the combined mouth plates; in having the inter- radial pair of marginal plates joined only by the adoral ends, and forming a A-shaped structure with the unpaired interradial plate. Rays slender, usually very deciduous, a nonmuscular symphysis or syzygy uniting first and second adambulacral plates and the dorsal part of the second and third ambulacral plates; adambulacral plates longer than broad, with few or no furrow spinelets, and a sharp, unmodified, sub- ambulacral spine; integument of disk thin, weak; mouth plates small, with small suboral spine; entrance of furrow into actinostome broad. Remarks.—This genus includes a number of species of the old genus Brisinga which are very distinct from the type, B. endacnemos. They are outwardly dis- tinguished by the delicate rays which are very deciduous, by the delicate dorsal skeleton, both of disk and rays, by the thin disk, and more definitely by the fact that the first adambulacral plate is not united with its neighbor of the adjacent ray, but is separated by the outer end of the combined mouth plates. Correlated with this, the first marginal plate is not joined to its vis-a-vis as in typical Brisinga, forming thus a pair of plates snugly apposed, above the closely apposed first adambulacrals. But instead they join only by their adoral or inner ends, and with the interradial plate form an inyerted Y-shaped structure, the two arms of which represent the first marginal plates, while the acute angle represents the interbrachial angle bounded by these plates. If the lateral face of a disk which has lost several rays is examined it will be noted that the rays have broken at the syzygial or nonmuscular symphysis between the first and second adambulacral plates. In Brisinga one sees two distal facets close together and immediately above them two smaller, usually unequal, closely joined facets—the distal ends of the first marginal plates. The two lower (adambulacral) facets are very slightly spaced. In Brisingella the adambulacral and marginal plate of each ray are joined, the former above the latter, but never those of adjacent rays. Always the interbrachial angle or sinus extends to the proximal end of the plates and keeps those of adjacent rays apart. More important still, in Brisinga the gonads are numerous in each ray and form a series of independent bodies along either side of the genital region. In a2 z ~ ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 13 Brisingella there are always two gonads to each ray, and although they may be branched each gonad has but a single aperture on the side of the ray at a little dis- tance from the base.’ Brisingella includes the following species: B. fragilis (Fisher), B. coronata (G. O. Sars), B. exilis (Fisher), B. pusilla Fisher, B. pannychia Fisher, B. tenella (Ludwig), B. monacantha H. L. Clark, and probably also the following species described by Sladen: B. verticillata, B. armillata, B. discincta, and B. membranacea. Among the species described by Perrier, the following belongs in this genus: B. mediterranea. KEY TO THE SPECIES OF BRISINGELLA HEREIN DESCRIBED a!. Costae 9 to 11, extending 4.5 r along ray, or about one-fourth total length of ray; disk plates not unusually few or widely spaced; disk spinelets usually two or three to a plate; the fur- row spinelet present on all plates except near end of ray; interradial plate not markedly convex or keeled; dorsal end of first ambulacral ossicle about twice as long as that of the pecan: 25) psec yr ap steceeay i eco aioe ee leeret ose ee. Leek eS te exilis. a?. Costae 20 or more extending far along the ray; disk spinelets usually one to a plate; interradial plate markedly convex; dorsal end of first ambulacral ossicle less than twice as long as that of the second. b!. Disk plates unusually few, widely spaced, embryonic, with ordinarily a single tiny spinelet, occasionally two, to each plate; furrow spinelet absent except an adoral one on first 3 toxl4 plates. fn 22rd josey eke es bee ahs gree eee ow pusilla, b?. Disk plates not unusually few, spaced about the length of the spinelets, which are about 0.5 mm. long; an adoral and an aboral furrow spinelet, extending far along ray pannychia. BRISINGELLA EXILIS (Fisher) Plate 2, Figures 2, 2a—2c; Plate 8, Figures 2, 2a, 2b Brisinga exilis FisHer, New Starfishes from Deep Water off California and Alaska, Bull. Bur. Fisheries for 1904, vol. 24, June 10, 1905, p. 318. Brisingella exilis Fisnpr, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 427. Bull. U.S. Nat. Mus. 100, vol. 3, 1919, p. 524. Diagnosis —Rays 10. R. 250 mm.; r 10 mm.; R=25 r; thickness of disk, 4 mm.; breadth of ray at base, 5 mm.; at widest part of genital inflation,6mm. Rays deciduous, delicate, long and very slender, with an attenuate lashlike outer portion; costal ridges, prominent, slender, well spaced, 9 to 11, opposite alternate adambula- cral plates, and extending 4.5 r along ray, or about one-fourth total length of ray; lateral spines long, very fragile, opposite alternate adambulacrals; adambulacral plates with one adoral furrow spinelet and 1 slender, delicate subambulacral; mouth plates with one to three actinostomial spinelets, often one aboral furrow spinelet, and one suboral sharp spinule; upper end of second ambulacral ossicle about half as long as first and third; a movable plate at upper end of the interradial plate, the latter with a flat or grooved surface. Description.—Disk thin with a beveled border, and not elevated above the rays to any extent. Integument of disk thin and very flexible, the plates delicate, round- ish, oval, elliptical, or irregular, with irregular patches of the integument between them. The plates touch or are slightly separated, and bear one to five, usually two 7G. O. Sars; On some Remarkable Forms of Animal Life from the Great Depths off the Norwegian Coast, Christiania, 1875, pl. 1, fig. 12a. 64406—28——2 14 BULLETIN 76, UNITED STATES NATIONAL MUSEUM or three, delicate, sharp, spinelets 0.5 to 0.75 mm. long and sheathed in delicate mem- brane. These groups of spinelets are spaced about 1 mm. apart in the center of disk, and near the border, about half that distance, or even less. Madreporic body prominent, on edge of disk. On its adcentral side is a group of plates (eight or nine) which are tightly fitted together, and combined are about as large as the madreporite. Interradial plate small, broader below than above (somewhat oval in form) the sur- face subplane sometimes with a shallow groove in the middle of the upper half. The lower end meets the inner ends of the interradial pair of marginal plates. (See pl. 2, fig. 2.) At the upper end of the interradial plate is an irregular thick movable plate in the abactinal integument. It may bear a few spinelets and is much larger and thicker than the other abactinal plates. No pedicellariae on disk. Rays fragile, very deciduous, the abactinal membrane thin and devoid of integu- mentary prickles. Costal ridges delicate, widely spaced (opposite alternate adam- bulacral plates), narrow, irregular, prominent, composed of elongate plates which imbricate by their ends. These plates in the proximal portion of the genital area, at least, bear one or two rather stout, subconical prickles, and in life each costal ridge is overlaid by a cushion of pedicellariae. Between the costae, and correspond- ing to the alternate adambulacral plates, is a transverse prominent saccular band of pedicellariae. These are continued throughout the ray, and after the costae have ceased they occur opposite about every adambulacral plate. The costae number 9 to 11, possibly 12 in some cases, and they extend 4.5 r along the ray, or only one- fourth total length of the ray. Lateral spines attached to the rather prominent lowermost plate of the costae, and hence at the upper edge of alternate adambulacral plates. They are very fragile and it is difficult to find a complete one. At the middle of the ray of a specimen from station 4387 the spine is 14.5 mm. long (=7 adambulacral plates) and one at the middle of the costal area is 9 mm. long (=4 adambulacral plates). Adambulacral plates comparatively slender, longer than broad, and at base of ray fully twice as long as the height seen from the side. Furrow margin deeply excavated. The armature consists of a very delicate furrow spinelet at the adoral end of plate, surmounting a slight boss and armed with a terminal pad of minute pedicellariae; and on the actinal surface of the distal half of the plate is a delicate subambulacral spine about 5 mm. long covered in life by a rather thick sheath closely beset with pedicellariae. This spine is shorter on the plates opposite which there is a lateral spine. The small furrow spinelet continues to very near the tip of ray. On the outer attenuate portion of ray the adambulacral plates are, of course, slenderer than proximally, and the furrow spinelet is spaced about one-third the length of the plate from the proximal end. The first adambulacral is joined to the second by a nonmuscular articulation. The ray breaks at this point. The first adambulacral plate is separated from that of the adjacent ray by the outer ends of the combined mouth plates. The inter- brachial angle is formed by the first marginal plates of each ray, which join by their inner ends, and form a reversed Y with the interradial plate. The first marginal lies along the upper edge of the first adambulacral; the second along the upper border of the second adambulacral, while there is a small third marginal above the third adambulacral, and the first costal arch commonly occurs at the distal end of the ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 15 plate. If the dorsal integument of disk is stripped off so that the upper end of the first two pairs of ambulacral plates can be seen, the length of the upper end of the first pair will be seen to be about twice that of the second pair. In the following species the length of the first pair is only slightly greater than that of the second. In exilis the length of the third and succeeding pairs is about twice that of the second, measured the same way. The articulation surface of distal face of second ambulacral ossicle is narrowly oval, more or less acute below, the height about equal to width of the combined pair. Actinostome 12.5 mm. in diameter. Mouth plates small, much narrower at the inner than at the outer end, where the combined width is about equal to the breadth of furrow at inner end of the plates. Armature: One short, delicate, acti- nostomial spinelet directed across mouth of furrow, and one small, tapered, sharp suboral spine at about the center of the plate. In the type about 20 per cent of the mouth plates have a small spinelet at the corner adjacent to the first adambulacral, and it is regularly present in a specimen from station 4387. This specimen has two or three actinostomial spinelets to each plate. Gonads (testes) two to each ray, and opening on each side at a distance of 4rfrom the base (opposite twentieth adambulacral). They have many slender branched lobes. Type.—Cat. No. 22348, U.S.N.M. Type-locality Station 4398, off San Diego, Calif., 32° 43’ 20N: whine Ade 10’ W., 620 fathoms, green mud, rocks; one specimen (disk and three rays). Distribution —Off southern California from San Diego to Santa Barbara Island, 448 fathoms to 1,059 fathoms, green mud. Specimens ecamined.—In addition to type: Station 4387 (probably 4387a is meant), vicinity of San Diego, Calif., 32° 32’ 40’’ N., 118° 04’ 20’’ W.; 1,050 fathoms, green mud; one specimen (disk and four rays). Station 4416, off Santa Barbara Island, Calif.; 448 fathoms, dark-green mud; one ray. Remarks.—I examined and compared directly with specimens of B. ewilis a ray of the type of B. tenella (Ludwig) from 1,322 fathoms, east of the Galapagos Islands. Although the disk of tenella is not known, the presence of only two gonads to each ray, as well as the general appearance of the rays, makes its generic position fairly certain. B. tenella differs from evilis in having 40 or more very closely placed costae, there being two, or sometimes three, to every adambulacral plate. The adambulacral plates, in addition to the subambulacral spine, bear one or two adoral furrow spinelets and one aboral furrow spinelet. The lateral spines, in spite of the crowded costae, are léss numerous than the adambulacral plates. They are at the upper border of each of two consecutive plates (.. ); then a plate is skipped (-_), somewhat as fol- lows, the dashes representing the plates missed (sixth plate): ..—- ..-—.- +7 ey Meee REE Oe aCe The short swollen genital region and numerous crowded costae give to B. tenella a considerably different appearance from that which is characteristic of the other known species of this group. 16 BULLETIN 76, UNITED STATES NATIONAL MUSEUM A nearer relative than tenella is Brisingella fragilis (Fisher) of the Hawaiian Islands, which is the type of the genus. This species is rather variable in regard to the adambulacral armature and the relative size of the secondary costae between the pri- mary ridges. But it differs from exilis in having on the proximal adambulacral plates an aboral furrow spinelet and also sometimes two or even three adoral furrow spine- lets; the genital area is longer than in exilis (6 to 8 r from base of ray) and the costae more numerous; the disk plates bear usually a single very small sharp spinelet; the interradial plate is subcarinate; the first marginal is shorter in proportion to its breadth at the inner end; the upper end of the second ambulacral ossicle is more than half that of the first; there are regularly three actinostomial spinelets, and two aboral furrow spinelets standing in a diagonal line with the suboral spinule. BRISINGELLA PUSILLA Fisher Plate 2, Figures 1, la-1f; Plate 8, Figures 3, 3a, 3b Brisingella pusilla Fisner, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 427. Diagnosis—Rays 10. R165+ mm.;r8mm., R=20+ r; thickness of disk, 2.5 mm.; breadth of ray at base, 4 mm. Similar in general appearance to B. exilis, having thin disk and deciduous, slender, flexible rays, thin delicate abactinal integu- ment, and very fragile spines. Differing from B. exilis in having 25 to 30 costae which extend at least three-fourths length of ray; comparatively few, widely spaced, embryonic abactinal disk plates, bearing one, or occasionally two, small spinelets; a narrower, keeled, interradial plate; second ambulacral ossicle more than half as long as the first, measured on the summit of the ridge; furrow spinelet confined to first few adambulacral plates (first 3 to 14). Description —Abactinal integument of disk very thin and translucent. Abactinal plates few, very small, and widely spaced, each with one, or sometimes two, very small sharp spinelets, some of which bear a minute pedicellaria at the base. The plates can only be seen when the integument is dried. They are irregular in form, 0.1 to 0.5 mm. in diameter and unevenly scattered, there being sometimes so much as 2mm. between plates. About 20 to 35 may be counted across the disk between the borders of the actinostome. Madreporic body prominent, convex, on the border of disk, with a number (five or more) of closely fitted plates on its adcentral side. These combined are about as large as the madreporite. Interradial plate narrow, promi- nently keeled, the upper end angular, the lower end truncate or slightly angular. It is narrower than that of ewilis and the surface is convex or keeled instead of being more or less plane, with typically a longitudinal groove. Rays very deciduous, slender, with an attenuate, flexible, distal portion. Abact- inal membrane very thin, devoid of intercostal spinelets or prickles. Costae delicate, rather widely spaced (opposite alternate adambulacral plates), and composed of slender, elongate, overlapping ossicles which bear each a conical sharp spinelet. On the proximal part of the genital inflation the ridges are bent distally as a rule, and are more or less irregular throughout the long costal region, which extends much beyond the genital area proper, or fully three-fourths the length of ray. There are 25 to 30 coste, the distal ones being very inconspicuous and difficult to determine unless the specimen is dry, There is a band of pedicellariae between each pair of costae, and ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 17 the ridges themselves are covered with minute pedicellariae. The first complete ridge usually meets the fifth adambulacral plate. Lateral spines very slender and fragile, usually closely appressed to side of ray. On the genital region they are about 7 mm. long (four adambulacral plates in length). At the middle of ray a spine measures 8 mm. (4.6 adambulacral plates) in length. Adambulacral plates slender, as usual in this genus, with a very concave furrow margin. Armature: On the first 3 to first 14 plates is a delicate furrow spinelet about as long as half the length of plate (or less) and spaced a third the plate’s length from the adoral end. Over the rest of ray there is no furrow spinelet. There is one slender subambulacral spine situated just aborad of the middle of the plate. Itis 4 mm. long (two adambulacral plates), or on alternate plates, between lateral spines, a little longer. The subambulacral and lateral spinelets normally are covered with a delicate sacculus beset with minute pedicellariz. The first and second adambulacral plates are joined by syzygy, or nonmuscular articulation. The first adambulacral plates of adjacent rays are separated, as in exilis, by the outer ends of the combined mouth plates. Interradial angle formed by the first marginal of each ray, which lies along the upper edge of the first adambulacral plate. These marginals join by their inner end and are also joined to the lower end of the interradial plate. The articulation surface of the ambulacral ossicle (the distal face of the second) where ray has been removed, is very small, broadly elliptical, and the combined width of the pair is considerably more than the height. They are smaller and broader than in exilis. The second ambulacral ossicle is two-thirds to three-fourths the length of the first, measured on summit of ridge. Mouth plates small, very similar in form to those of exilis but slightly narrower. Armature: One or two actinostomial spinelets; when there are two, one is usually directed over the peristome and one across mouth of furrow; rarely there may be an aboral furrow spinelet. There is one slender, sharp, suboral spine situated on the middle of the plate, and equal to the length of the first two adambulacral plates. In some specimens the marginal spinelets are absent. Type.—Cat. No. E. 1414, U.'S.N.M. Type-locality Station 4427, off Point San Pedro, Santa Cruz Island, Calif.; 447 to 510 fathoms, black mud and rocks; 18 disks, 15 rays, more or less broken. Distribution.—Off southern California, from San Diego to Santa Cruz Island, 301 to 1,059 fathoms, green and black mud. Specimens examined.—Five disks, 27 rays, from the following stations: Station 4333, off Point Loma, Calif. (13.6 miles southwest), 301-487 fathoms, green mud; bottom temperature, 40.1° F.; about 16 rays, in fragments, one disk. Station 4387 (probably 4387a@), vicinity of San Diego, Calif., 32° 32’ 40’’ N., 118° 04’ 20’ W.; 1,059 fathoms, green mud; three disks, nine broken rays. Station 4416, off Santa Barbara Island, Calif., 448 fathoms, dark green mud; disk and two rays, broken. Remarks.—The differences which separate this species from exilis are mentioned in the synopsis, the diagnosis, and the foregoing description. It differs from B. tenella (Ludwig) in having widely spaced costae which extend three-fourths the length of ray, in having no furrow spinelets except a small adoral one on the first few plates of the series, and in having much smaller articulation facets on the proximal face of 18 BULLETIN 76, UNITED STATES NATIONAL MUSEUM the third pair of ambulacral ossicles. In tenella each facet is higher than wide and the combined pair about as broad as the height (in pusilla the combined pair is much broader than high, and in rays of the same size actually much smaller). The disk of tenella is unknown. The rudimentary scattered plates of the disk will at once separate this species from fragilis, which, furthermore, does not have costae on the outer half of ray, has regularly three actinostomial spinelets and two aboral furrow spinelets to each mouth plate; in addition the first marginal plates of pusilla are slenderer, the outer end of the combined marginal plates is broader, and the rays decidedly narrower and weaker to disks of the same size. Putting it conversely, the disk of fragilis is proportionately smaller. BRISINGELLA PANNYCHIA, new species Plate 8, Figure 4, 4a Diagnosis.—Resembling B. fragilis in having a long costal region with numerous, rather widely spaced costae, in having the dorsal end of the first ambulacral plate less than twice the length of the second, and in having both an adoral and aboral furrow spinelet. Differing from B. fragilis in lacking entirely any trace of the secondary, intercostal, calcareous, incomplete arches, in having coarser costal spinelets, and in having conspicuously longer and less numerous abactinal disk spines. Rays 10; r=8 mm.; rays incomplete. Description.—Disk of the usual Brisingella form, thin, with a beveled margin. Spinelets about 0.5 to 0.6 mm. in length, spaced about the same amount, generally solitary, but occasionally with two or three to a plate, very delicate and sharp, but when incased in the usual membranous covering blunt and papilliform. They are fully twice as long as the disk spinelets of B. fragilis and much less numerous. As compared to B. pusilla, the disk spinelets of pannychia are more numerous and some- what longer; they appear to be more like those of pusilla than like the minute close- set spinelets of fragilis. There are relatively few tiny pedicellariae attached to the basal portion of the spinelets. Interradial plate rather prominently convex but with a more rounded surface than in pusilla; the plate is a little shorter and broader than in either pusilla or fragilis. Rays represented only by basal parts, none complete; longest fragment with 19 costae; there are apparently many more. Costae slender, spaced 3 to 5 mm. and bearing relatively few spaced, sharp spinelets about 0.75 mm. long. There is a slender rather inconspicuous intercostal band of pedicellariae. The costae correspond to every alternate adambulacral and there is a slender lateral spine on either side at the base of each arch, as usual in this genus. When fully developed this spine is equal to a little over three consecutive adambulacral plates in length. Adambulacral armature: One aboral furrow spinelet about as long as one-third the length of the plate; an adoral spinelet about two-thirds the length of the plate and spaced about half its own length from the adoral margin of plate; a slender sub- ambulacral spine (none perfect). There is a syzygy between the first and second adambulacral plates. The second ambulacral ossicle is about two-thirds the length of first measured on summit of ridge. The mouth plates are in general form very similar to those of pusilla and fragilis; they extend externally between the first adambulacrals of adjacent rays, these plates ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 19 being conspicuously separated and touch the first marginal plates. There are three marginal spinelets to each plate, two on actinostome and one in the furrow separating the first and second tube-feet. The suboral, situated at about the middle of the plate but nearer the furrow than the median suture, is short and slender, a little longer than the width of the actinostomial margin of combined plates. The spinelets bear the usual terminal pads of pedicellariae. In B. fragilis there are generally three actinostomial spinelets and two aboral furrow spinelets. The suboral spine is small and stands in line with the furrow spinelets, forming a diagonal series. In B, pusilla there is usually only one actinostomial spinelet, rarely one aboral spinelet (usually none), and the slender suboral spine is longer than usual in the genus Brisingella. The articulation surface (distal) of the second ambulacral ossicle (where a ray has been removed) is very small, broadly elliptical, and the combined width of the pair exceeds the height. This character is more like the same in B. pusilla than in B. fragilis, where the distal facets are relatively larger. The first marginal plates are characteristic of the genus in their relation to the adambulacrals and the interradial. Type.—Cat. No. 37038, U.S.N.M. Type-locality —Station 4767, Bowers Bank, Bering Sea, 54° 12’ N., 179° 07’ 30’ E.; 771 fathoms, green mud; bottom temperature, 36.5° F. Remarks.—The synopsis of species will sufficiently indicate differences between this species and the California forms. Brisingella coronata (Sars) is not closely related, as it is characterized by a short costal region and only 10 to 14 skeletal arches which do not extend more than 6 r from the base of ray. The adambulacral plates have two adoral furrow spinelets. The species is the largest known in this genus. Sars figures a specimen with a disk 28 mm. in diameter and a ray 320 mm. long, which is large even for a typical Brisinga. Genus ASTROSTEPHANE Fisher Astrostephane Fisuer, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 421. Type, Brisinga moluccana Fisher; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 525. Diagnosis.—Differing from typical Brisinga in having but two gonads to a ray, and the proximal adambulacral plates longer than high, as in Brisingella. In appear- ance, especially that of rays, closely resembling Brisingella, but differing in having the first adambulacral plate tightly joined for its whole length to that of the adjacent ray, and in having directly above these a closely joined pair of first marginal plates, as in Brisinga and Craterobrisinga; in having very prominent suboral spines bent at the base so that they extend horizontally into the actinostome. A nonmuscular joint, or syzygy, between the first and second adambulacral plates and between the upper part of the second and third ambulacral plates; costae thin, well spaced; inter- costal integument without spinelets, rather delicate; only one subambulacral spine; gonads large, with numerous lobes emptying by a single aperture just above the ambu- lacral plates a little over 2 r from the base of ray; disk with close-set small spinelets. Remarks.—It seems probable that this genus is more nearly related to Bris- ingella than to Brisinga. Fortunately there are two very distinct species, so that the characters given in the diagnosis as of generic value are probably reasonably accurate. If it is contended that the condition of the interradial pair of adambulacral plates, whether separated (Brisingella, Astrolirus) or joined (Brisinga, Craterobrisinga, 20 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Stegnobrisinga, Astrostephane), is dependent upon the number of rays, it may be stated that A. acanthogenys with 11 rays has the plates as tightly joined as A. moluc- cana, with 16 rays. In Brisingella, where this interradial pair of adambulacrals is separated by the outer end of the combined mouth plates, so that they do not touch by the lateral faces, the first marginal plates have a different relation also. With the unpaired interradial plates they form an inverted Y, each arm being applied to the upper edge of the first adambulacral plate, and the angle of the A being that of the interradius. In Oraterobrisinga alberti (Hawaiian Islands) which has nine rays (less than Brisingella fragilis, type), the mouth plates do not separate the first or inter- radial pair of adambulacrals as might be expected if the number of rays only deter- mined the characteristic structure of the interradial angle of Brisingella. The proximal part of the plates in alberti are normally joined, and the closely apposed first pair of marginals has slipped down between the outer ends of the adambulacrals, cementing firmly the ring of plates. There is no hint of the separation of the marginals to form the 4 of Brisingella. This genus is not represented in the north Pacific region. A. moluccana was taken in 265 to 559 fathoms in the Molucca Islands and Celebes; A. acanthogenys was dredged in 172 fathoms, Lingayan Gulf, Luzon. Genus STEGNOBRISINGA Fisher Stegnobrisinga Fisurr, New East Indian Starfishes, Proc. Biological Soc., Washington, vol. 29, p. 33, Feb. 24, 1916 (subgenus). Type, Brisinga (Stegnobrisinga) placoderma Fisher; Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 428 (genus); Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 530. Diagnosis—Resembling Brisinga in general appearance, and especially in having definite transverse skeletal ridges, or costae, on the genital region, but differ- ing in having the integument between the costal arches of ray strengthened by many close-set, mostly contiguous or sometimes overlapping papery, spineless plates of irregular form, completely filling the interspaces; in having two gonads to each ray. Proximal subambulacral spines acicular; first adambulacral plate and first mar- ginal plate joined for their whole length to the respective plates of adjacent ray; thus there are four closely joined plates in each interradius; a nonmuscular symphysis, or syzygy, between the first and second adambulacral plates and between the upper parts of second and third ambulacral plates, as in Brisinga. Known only from a single species, S. placoderma, China Sea to Buton Strait, Celebes, 525 to 559 fathoms. Genus ASTROLIRUS Fisher Astrolirus Fisher, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, pp. 424, 428. Type Brisinga panamensis Ludwig; Fisher, Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 504. Diagnosis.—Resembling Stegnobrisinga in the presence of spineless, immersed, fenestrated thin plates in the intercostal integument, but differing in the structure of the interbrachial angle, where the first pair of adambulacral plates are not joined together by the interradial faces but are separate; first pair of marginal plates not closely united by their interradial faces, but only by the adoral ends, to which also is closely united the lower end of the interradial plate, forming a rude reversed Y of ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 21 which the angle is the apex of the interbrachial angle, and the arms are the first mar- ginal plates; proximal adambulacral plates not higher than long; gonads two or four to each ray. The type, Brisinga panamensis Ludwig, is the only species known. The genus has much the same relation to Stegnobrisinga that Brisingella bears to Brisinga, with the exception of the gonads, which are two to each ray in Stegnobrisinga, and two or four in Astrolirus. Genus FREYELLASTER Fisher Freyella FisHer (not Perrier), Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 428. Freyellaster Fisher, Ann. and Mag. Nat. Hist., ser. 9, vol. 2, 1918, p. 104. Type, Freyella fecunda Fisher, Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 537. Diagnosis—Brisingidae with numerous gonads arranged serially along either side of the more or less inflated. genital region of ray, each opening by its own pore; plates of genital region forming a continuous covering or armor, more or less spin- iferous, and not segregated as independent skeletal arches, separated by intervals without plates; no papulae; in interbrachial angle the first pair of adambulacral plates (of adjacent rays) closely joined throughout their length, and directly above them is a pair of closely joined first marginal plates; primary apical plates not con- spicuous; a nonmuscular symphysis, or syzygy, between the first and second adam- bulacral plates, and between the upper part of the second and third ambulacral plates. Remarks.—This group includes those species of the old genus Freyella in which the gonads are numerous and arranged in series along either side of the ray, as in typical Brisinga. In this restricted genus Freyellaster, as in the restricted Brisinga, the first adambulacral plate is closely united to its fellow of the adjacent ray, at the apex of the interbrachial angle; and immediately above them and joined to their upper side is a closely apposed pair of marginal plates, the first of a series which extends a variable distance along the base of the ray just above the adambulacral plates. The adoral end of these marginal plates abuts against the base of the inter- radial plate. In some species part of the second adambulacral plate, as well as the first, is joined to its vis-a-vis. In addition to the California species, the following belong to Freyellaster: F. spatulifer (Fisher), Macassar Strait; Ff. scalaris (A. H. Clark), Galapagos Islands; probably F. polycnemus (Sladen). FREYELLASTER FECUNDUS (Fisher) Plate 3, Figures 1, la-1f; Plate 7, Figure 2; Plate 9; Plate 12, Figure 1 Freyella fecunda Fisuer, Bull. Bur. Fisheries for 1904, vol. 24, June 10, 1905, p. 319. Freyellaster fecundus Fisher, Ann. and Mag. Nat. Hist., ser. 9, vol. 2, 1918, p. 104; Bull. U.S. Nat. Mus. 100, vol. 3, 1919, p. 538. Diagnosis —Rays 13. R. 330 mm., approximately; r 13.5 mm.; R=approxi- mately 25 r; greatest diameter of disk, 27 mm.; of elevated portion, 24 mm.; thick- ness of disk, 5 mm.; diameter of ray at base, 6 mm.; at widest portion of genital inflation (25 to 75 mm. from the base), 7.5mm. Genital region very extensive, com- prising about half the length of ray, and not conspicuously inflated; plates thin, delicate, beset with one to three small prickles, pretty evenly distributed, but more 22 BULLETIN 76, UNITED STATES NATIONAL MUSEUM numerous along the mid-dorsal line; disk with solitary spinelets spaced about their own length; first 12 or 15 subambulacral spines with a truncate, circular flaring tip; proximal plates with three aboral spinelets in a transverse series, and a subambulacral, also close to distal border; plates of outer part of genital region with two aboral spinelets (as) or wi *); no transverse rows of more prominent abactinal spines; lateral spine opposite alternate adambulacrals, longer than the subambulacral spine. Description —The rays are very long, narrow, tapering gradually, a trifle nar- rower at the base than throughout the very extensive genital region, which is not inflated at all conspicuously. The rays are subcylindrical at the base, depressed on the genital region and of the ordinary three-sided form beyond the genital region. The latter, or, more correctly speaking, the portion of the ray covered by the small papery abactinal plates, comprises nearly or sometimes quite half the total length of ray. The edge of the fairly large disk is evenly rounded and somewhat undulating in outline. The abactinal integument is very tight and is beset with equal, solitary, small, terete, blunt spinelets, spaced about their own length, those about the anal aperture being a trifle longer than the others. The shape of the spinelets is due to the membrane investing each one, as the calcareous portion is acicular. Interradial plate rather high and narrow, confined to side wall of disk. The abactinal membrane of rays is rather thin and papery, the delicate plates being invisible except in a thoroughly dried specimen. They are very thin, consist- ing of a single layer of delicate calcareous network, and are irregular in outline. The plates are not uniform in size and overlap by the edges. Over the extensive genital region the integument is beset with minute, evenly spaced prickles or spinelets, incased in membrane which gives them a blunt appearance. There are one to three, commonly one or two, to each plate, and they are shorter and more widely spaced than on the disk; those of the midradial area are more closely placed than are those on the sides of the ray. On the outer part of the genital region the prickles are still more widely spaced and many of the plates are without them. Except on the first 50 mm. of the ray, the indistinct bands of microscopic pedicellariae from each lateral and ambulacral plate proceed toward the median radial line, before reaching which they break up. On the semitransparent membrane of the outer half of the ray, where there are no mtegumentary prickles, these bands of pedicellariae are more conspicuous, and extend entirely across the abactinal surface, but are frequently irregular on the median keel of the ray. Extending upward from the rudimentary marginal or lateral plates are a few plates stouter than the other abactinal plates which sometimes reach halfway to the median radial line. Partly fused to the lateral face of alternate adambulacral plates is a lateral plate, bearing a long, slender spine (18 mm.) sheathed in membrane covered with micro- scopic pedicellariae. (On plates adjacent to the lateral spine, the subambulacral spine is conspicuously shorter than on alternate plates.) At the base of ray are five marginal plates without spines. The first of these is strongly fused with its fellow of the adjacent ray, at the apex of the interbrachial angle and above the first adambulacral plates. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 23 Adambulacral plates longer than high and on the basal portion of ray about as wide as long. The armature consists of, on the aboral margin of the plate, a trans- verse series of three spinelets and one spine (the subambulacral), or beyond the middle of genital region two spinelets and one spine. At the base of the ray the two inner spinelets are subequal-and the third longer, or the innermost is slightly shorter than its plate, the second subequal to the plate in length, and the third about 1.5 plates in length. The subambulacral spine is 10 to 11 mm. long or 4.5 to 5 plates. On plates which have a lateral plate and spine on their outer side, the subambulacral is shorter than on alternate plates with no lateral spine. The first 12 to 15 subambulacral spines have a flaring, circular, truncate tip beset with numerous little points as in Craterobrisinga. The sixth to ninth spines have the broadest tips. On the distal attenuate portion of the ray there is one furrow spinelet and one subambulacral, two to the plate, as over most of the ray of the immature example. First adambulacral plate joined to its fellow of adjacent ray, and proximal ends of the second plates touching one another. Actinostome rather wide, 16 mm. in diameter. Mouth plates small, incon- spicuous, rather narrow, with a flaring inner or free margin, the combined pair being shield-shaped. Armature consists of three or four membrane-invested pedicellariae bearing spinelets on the inner, free, flangelike margin of the plate, that nearest the median suture the shortest, the rest evenly graduated in size outward. At the aboral end of the plate are one or two similar spinelets reaching nearly across furrow. On the actinal surface two much heavier and larger, pointed, sacculate spinules stand in a longitudinal series, the inner the longer, and slightly nearer the median suture. Sometimes there is only one spine, or as many as three. Madreporic body small, subtubercular, situated near margin of raised portion of disk. Its borders are beset with numerous spinelets. The articulating surface of the ambulacral plates, on the border of disk where a ray has been broken off, is small, about 2.25 mm. high, and oval in form, slightly broader above than below. Color in life: Abactinal surface of disk flame scarlet; rays salmon pink with a yellowish cast, much lighter than disk; edges of furrow pinker; spines salmon pink; tube-feet pinkish orange. Immature specimen.—An example having R 99 mm. has the full number of rays. The genital region extends a little less than one-third the total length of ray. The prickles of the middorsal area are less compactly placed, and-the plates are even thinner than in the adult. On the first eight or nine adambulacral plates there are two aboral spinelets and the large spine; beyond that point only one furrow spinelet and the subambulacral. The proximal subambulacral spines are not much enlarged at the tip and only the first four or five are modified. The mouth plates have only one suboral to each plate, and there are two actinostomial spinelets, the outer at the entrance of the ambulacral furrow, the inner immediately adjacent to the outer spinelet and slightly spaced from the median suture. Anatomical notes—There are along each side of the ray 20 to 23 mature gonads in the form of independent globular sacs, 2 to 3 mm. in diameter, attached to a genital stolon. Beyond these are about 20 immature, often very small, gonads, which extend beyond the end of the long genital region, or a distance equal to about five times the 24 BULLETIN 76, UNITED STATES NATIONAL MUSEUM diameter of disk (10 r) from the base of the ray. The mature gonads end at a distance of about 5 r from the base of ray. The hepatic coeca extend nearly as far as the im- mature gonads or about 10 r from base of ray. The exposed ridge of the ambulacral ossicles toward the coelom is roughened by numerous minute spiny points. Type.—Cat. No. 22349, U.S.N.M. : Type-locality.—Station 4530, 6.8 miles northwest of Point Pinos, Monterey Bay, Calif.; 847 to 755 fathoms, soft gray mud; four specimens. Distribution —Taken only off Point Pinos, Calif., in 755 to 1,062 fathoms, on soft gray mud and on hard sand and mud. Specimens examined.—Seven; four from type-locality and three from station 4537, 7.4 miles northwest of Point Pinos, 1,062 to 861 fathoms, hard sand and mud; bottom temperature, 38.5° F., approximately. Genus FREYELLA Perrier Freyella Perrier, Ann. sci. nat., zool., vol. 19, art. 8, 1885, p. 5. Type Freyella spinosa, first species, by subsequent designation, Fisher, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 428; ser. 9, vol. 2, p. 104. Freyellidea Fisner, Ann. and Mag. Nat. Hist., ser 8, vol. 20, 1917, p. 429. Type Freyellidea microplaz; also Ann. and Mag. Nat. Hist., ser. 9, vol. 2, p. 104. Diagnosis.—Differing from Freyellaster Fisher in having only two gonads to each ray, in having a normal muscular symphysis between the first and second adam- bulacral plates (no syzygy), in lacking marginal plates entirely in the interbrachial angles, and in having the first adambulacral plates either joined, with tissue between or else separated nearly or quite to their proximal ends. Touching the lower end of the interradial plate is a pair of very inconspicuous plates lying in the same plane, and superficially appearing to be a portion of the interradial plate. They are really the extreme outer end of the mouth plates. They have the appearance of being separate plates because the inner end of the first pair of adambulacral plates nearly or entirely segregates them from the actinal or spine-bearing surface of the mouth plates. In those genera which have marginal plates in the interradius, this dorsal part of the mouth plate is entirely hidden by the marginals. Proximal subambulacral spines usually with modified tips. Remarks.—The species of this genus superficially resemble those of Freyellaster. I do not think they are so near to that group as to Astrocles. Both Freyella and Astrocles have only two gonads, and lack the marginal plates which form a character- istic part of the skeleton of the interradial angle in Freyellaster. I have examined the following species which belong to this genus: Freyella spinosa Perrier, elegans Verrill, insignis Ludwig, propinqua Ludwig, pacifica Ludwig. H. L. Clark ® has reported F. tuberculata Sladen from 2,320 fathoms, eastern tropical Pacific, and has added the following new species from the same region: F. brevispina, octoradiata, and oligobrachia. Without knowing the disposition of the gonads it is not possible to be certain that the following species belong to Freyella: sexradiata Perrier, benthophila Sladen, fragilissima Sladen, heroina Sladen, dimorpha Sladen, remer Sladen. fF. bracteata Sladen is a synonym of elegans according to Verrill. z aa Mem. Mus. Comp. Zodl., vol. 29, 1920, no. 3, pp. 108-113, pls. 5, 6; the region is between 9° 2’S. and 0° 3’ N. and 83° and 123° W. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 25 SYNOPSIS OF SPECIES OF FREYELLA HEREIN DESCRIBED a', Plates of genital region smaller (20 to 30 in a line across ray at widest part) and very numerous; spinelets very small in small groups; one aboral furrow spinelet; proximal subambulacral spine terete with a slightly capitate truncate tip; three actinostomial oral spinelets; pedi- cellanine sallmibn bees hare ee Sa pe | a te microplaz. a*. Plates of genital region large (8 to 12 in a line across ray at widest part) and fewer; spinelets larger; one or two aboral furrow spinelets; proximal subambulacral spines spatulate, with 2 to 4 pronged tip, or with prongs only; two actinostomial oral spinelets; pedicellariae of adambulacral, oral, and abactinal spinelets large_________..._______________- insignis. FREYELLA MICROPLAX (Fisher) Plate 4, Figures 1, la-1f; Plate 7, Figure 1; Plate 10; Plate 12, Figure 4 Freyellidea microplax FisHer, Ann. and Mag. Nat. Hist., ser 8, vol. 20, 1917, p. 430. Freyella microplaz FisnEr, Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 538. Diagnosis—Rays 12, not deciduous, only moderately long, with a short swollen genital region about 4 r in length. Disk closely covered with short spinelets, four or five to a plate; genital region of ray covered with small transversely oriented, elliptical, somewhat irregular plates bearing groups of two to eight small spinelets; 19 or 20 plates can be counted across ray at widest part. Short lateral spine opposite alternate adambulacral plates. Adambulacral armature, one aboral furrow spinelet, and one subambulacral spine, with truncate enlarged tip at base of ray; first adam- bulacral plates of adjacent rays not fused, the outer end of mouth plates intervening; oral armature: three actinostomial spinelets and one short, sharp, suboral spine. R 170+ mm.,r10mm., R=17+ r; thickness of disk, 4 mm.; width of ray at base, 4.5 mm.; breadth of actinostome, 13 mm. Description—The top of the disk is flat and only slightly elevated above the rays, which slope gradually into the disk without a break, or shoulder. The disk is thickly covered with terete blunt spinelets usually four or five to each plate. The spinelets are sheathed in membrane which gives them their characteristic blunt form, the calcareous portion being very sharp. Certain scattered plates have only two or three spinelets. The spinelets are about 0.5 mm. long and those of each plate tend to radiate apart slightly, the separate groups being usually less than 0.5 mm. apart. There are a few larger plates observable in favorable specimens which have 15 to 20 spinelets. These are probably primary apical plates. At the base of the spinelets are one to several very minute inconspicuous pedicellariae. The genital region is conspicuously inflated, short, and thickly covered with very numerous transversely oriented groups of about five (two or three to five, less com- monly, six, seven, and eight) delicate, skin-covered, blunt spinelets (very sharp when dried) borne on elliptical transversely oriented plates which usually are slightly spaced when the ray is swollen to its maximum. When the ray is only slightly swollen, the plates touch, especially in the mid-dorsal region. Minute, inconspicuous pedicellariae are present on the basal portion of the spinelets. The spaces between the groups of spinelets are small, usually about one-half the width of the group of spinelets in undried specimens. Beyond the region of plates (which is about twice the diameter of disk from base of ray) there are broad bands of pedicellariae, the alter- nate ones usually much interrupted. The spaces between the bands are less than the width of the band itself. 26 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Lateral spines opposite alternate adambulacral plates. They are very slender but are heavily sheathed with membrane. At the middle of the genital area they are about the length of four adambulacral plates, and beyond the genital region, of 5 to 5.5 adambulacral plates. The pedicellariae covering the sheaths are very small. Adambulacral plates of genital region short, the width at first exceeding the length, but at the outer limit of the genital region the plates are slightly longer than wide. Armature consists of one aboral furrow spinelet, a little shorter than the plate (measured at middle of actinal face) and one subambulacral spine next to the aboral border, but on the first 10 plates occupying a considerable part of the surface of plate. The furrow spinelet is sometimes clavate at the tip, and its sheath is rather plentifully supplied with small pedicellariae. A variable number of the proximal subambulacral spines usually from about the third to the tenth or twelfth, have a truncate swollen tip, which varies considerably in size. Sometimes it is scarcely broader than the rather thick spine; again, it is nearly twice the breadth near tip. These proximal spines are a trifle over two adambulacral plates in length; farther along, after they become sharp, they are about three plateslong. The pedicellariae are on the outer side of the spine. On the terminal portion of the ray the furrow spinelet is lacking. The first adambulacral plate is not in contact with that of the adjacent ray, the outer end of the combined mouth plates leaving a narrow interval between the two. There is no syzygy between the first and second adambulacral plates. The articulating surface of the ambulacral ossicles, after a ray is detached, is small, broad above and narrow below, rather narrowly cordate in outline. The mouth plates are rather broad at the outer end. Actinostomial margin with three spinelets, the innermost the shortest, and occasionally there is a rudi- mentary spinelet on the furrow margin adjacent to first adambulacral plate. Each plate bears one suboral spine about as long as the first two adambulacral plates. Anatomical notes—Gonads, two to each ray with six or seven divisions to each, which extend along the ray a distance only a little greater than the diameter of disk. The coeca extend about twice as far; or to the end of the genital region. The inner surface of the ambulacral ossicles is smooth. Although the proximal adambulacral plates of adjacent series are not in contact at the base of ray, they are not separated by an azygous plate as in Colpaster. ‘The narrow exposed outer part of the combined mouth plates intervenes between the proximal ends of the first adambulacral plates of the two adjacent series, and continues upward to abut against the lower end of the interradial plate. The surface of this dorsal extension of the oral plates is flush with that of the interradial plate. The dividing suture between the two dorsal parts of the pair is at the bottom of a shallow sulcus which is continued above upon the surface of the interradial plate. Unless the specimen is dry or treated with caustic potash, it is not easy to distinguish the dividing sutures, and consequently the three plates appear to be one large interradial plate. The outer sides of each of these dorsal extensions abuts against the first adambulacral below and the second adam- bulacral above. The upper end as mentioned above rests against the lower end of the elongate, narrow, vertical interradial plate. (Pl. 4, fig. 1a.) Type.—Cat. No. E. 1415, U.S.N.M. Type-locality.—Station 3342, off British Columbia (52° 39’ 30’” N., 132° 38’ W.); 1,588 fathoms, gray ooze and coarse sand; bottom temperature, 35.38° F.; 12 speci- ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 27 mens. ‘Taken also at station 4537, 7 miles northeast of Point Pinos, Calif., 1,062 to 861 fathoms, hard sand, mud; bottom temperature, 38.5° F.; one specimen. Distribution.—British Columbia to central California, 861 to 1,588 fathoms, mud and sand; temperature range, 35.3 to 38.5° F. Remarks.—I have examined a ray of Freyella propinqua Ludwig and a ray of F. pacifica Ludwig. These two, as well as F. elegans Verrill, have the same type of adambulacral armature, namely, one subambulacral spine and one aboral furrow spinelet, and in this respect agree with F. microplax. But microplax differs from these three species in having much more numerous and smaller plates on the genital region of the ray, and as compared with elegans much more numerous and smaller disk plates. The spinelets of the disk and rays of microplax are much smaller—very small, in fact—and as the plates are diminutive, so the groups of spinelets are also smaller, much closer together, and correspondingly very much more numerous. FREYELLA INSIGNIS Ludwig Plate 3, Figure 2; Plate 4, Figure 2, 2a; Plate 8, Figure 1 Freyella insignis Lupwie, Mem. Mus. Comp. Zodl., vol. 32, 1905, p. 272, pl. 32, figs. 188, 189. Diagnosis.—Rays 11 (to 13 in typical form); in California specimen, R 104 mm., r5.5mm., R=19r. (Ludwig gives R=20r and R=17.6r.) Disk thickly covered with fairly close-set sharp spinelets, two, three, or even more to a plate; genital region of ray about 3 r in length, covered with relatively large, closely fitted, roundish or irregularly elliptical plates bearing 7 to 20 spinelets (only three or four in the Cali- fornia example) which form transversely oriented groups; lateral spines slender, opposite alternate adambulacral plates, beginning with the fifth; adambulacral arma- ture: one or sometimes two aboral furrow spinelets (regularly two in California variety) and one subambulacral spine, those of the genital region modified, with a more or less spatulate tip ending in two to four points or prongs; mouth plates with two spinelets at mouth of furrow and one adjacent to first adambulacral plate; suboral, one, rather short and pointed; gonads two to each ray, each with a single aperture on the side of ray 1 r from base. Description —Disk firmly plated, with two, three, or sometimes even more, relatively conspicuous, sharp, slender spinelets to each plate. The spinelets are fairly close-set and often bear a relatively large pedicellaria. Genital region of ray about 3 r in length, only slightly swollen, and covered with relatively large closely fitting spiniferous plates, the spinelets forming spaced groups, transversely oriented, of three or four spinelets to a plate. The spinelets are rela- tively large, being 0.4 to 0.5 mm. long. They tend to form interrupted lines crosswise to the ray, and at the distal end of the genital region the plates are more or less independent, forming one or two poorly defined, independent arches. On the sides of the ray just above the adambulacral plates the integument is bare except for rudi- mentary arches reaching alternate adambulacral plates. This is probably due to the immaturity of the specimen. Beyond the genital region the ray is crossed by a broad band of pedicellariae opposite each adambulacral plate. First lateral spine attached to upper border of the fifth adambulacral plate. The first spine is short, as usually the case; the second equals 2.5 adambulacral plates in length; the third equals 3; the fifth equals 3.5; at about the middle of ray the spine 28 BULLETIN 76, UNITED STATES NATIONAL MUSEUM equals 5 plates in length. It is covered with a sheath closely beset with minute pedicellariae. Adambulacral plates rather slender, longer than broad. Armature consists of two furrow spinelets at the aboral end of the plate, on the distal apophysis, the prox- imal spinelet usually a little the longer and about equal to the length of the plate measured on the actinal surface. A little aboral to the middle of the plate is the subambulacral spine which on the first nine plates has a broadened two or three pronged tip. These modified spines are about two adambulacral plates in length, while the sharp ones are a trifle longer. A few plates have a second shorter subam- bulacral near the first but it is not normal. On the distal attenuate portion of the ray where the ambulacral furrow is very narrow, the furrow spinelets are lacking. Both subambulacral and furrow spines are liberally supplied with pedicellariae, those on the furrow and proximal half of the subambulacral are conspicuously larger than the pedicellariae of the lateral spines and distal half of the subambulacral spines. Ludwig states that the adambulacral plates of his specimen of insignis have a single furrow spinelet. I have a specimen from station 3381, Gulf of Panama, one of the four which he lists, in which a considerable number of the plates have two aboral furrow spinelets. Mouth plates small, with wide median suture, and very little modified from a pair of adambulacral plates. Armature consists of two spinelets on actinostomial- furrow corner of the plate (sometimes three) and one spinelet on the distal furrow corner, all provided with good-sized pedicellariae. There is a single slender, blunt suboral spine about two adambulacral plates in length. The apex of the interbrachial angle nearly touches the mouth plates, and is bounded by the first adambulacral plates, above which there are no prominent marginal plates as in Freyellaster. The proximal ends of the first pair of adambulacral plates in each interbrachium touch, but the plates are not joined by their lateral faces as in Freyellaster. Types.—In U. S. National Museum. Type-locality.— Gulf of Panama. Distribution —Gulf of Panama to southern California; 1,772 to 2,228 fathoms on gray mud, green mud, brown mud, and globigerina ooze; temperature range, 35° to 36° F. Specimens examined.—Station 4397, off Santa Catalina Island, Calif. (83° 10’ 15’” N., 121° 42’ 15’” W.); 2,196 to 2,228 fathoms, gray mud; bottom temperature, 35° F.; one specimen. Station 3381, Gulf of Panama; 1,772 fathoms, green mud; bottom temperature, 35.8° F.; one specimen. Remarks.—The single Californian specimen is small and presents slight differences from the typical form from off Panama. There are regularly two aboral furrow spinelets, instead of usually one (occasionally two), and the disk spinelets are not so densely placed, nor are there so many spinelets on the abactinal arm plates. But the California specimen is immature, which would account for the fewer disk spinelets and fewer spinelets on the abactinal plates of the ray. It is not possible to determine whether this specimen represents a distinct northern race. It lives in somewhat deeper water than the southern form. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 29 Genus ASTROCLES Fisher Astrocles FisHer, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, pp. 426, 430. Type A. actinodetus Fisher; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 504. Diagnosis.—Related to Freyella but plates of ray localized in transverse arches separated by intervals without plates; plates flat, not forming prominent carinate costae as in Brisinga; gonads two to each ray, opening each by a single aperture on side of ray a little less than 1 r from the disk; furrow spinelet and proximal subambu- lacral spines with expanded modified tips; in interbrachial angle first pair of adjacent adambulacral plates joined only at proximal end, not for their whole length as in typical Freyellaster; no prominent pair of first marginal plates directly above the first pair of adambulacrals; touching the lower end of the slender interradial plate is a pair of small plates. These are the outer ends of the mouth plates which project dorsally behind the proximal ends of the first pair of adambulacral plates, as in Freyella. The adambulacral plates segregate this dorsal part of the mouth plates from the actinal spine-bearing portion; first and second adambulacral plates as well as the upper part of the second and third ambulacrals joined by a normal muscular symphysis; no syzygy present. Remarks.—This curious genus agrees with Freyella in certain important features— the absence of a proximal adambulacral syzygy, absence of marginal plates above the first few adambulacral plates, and presence of only two gonads to each ray. I think the independent abactinal skeletal arches of the ray have nothing to do with those of Brisinga. The plates are flattish and resemble more nearly segregated abactinal plates of Freyella than they do the slender compressed costal plates of Brisinga and near allies. ASTROCLES ACTINODETUS Fisher Plate 4, Figures 3, 3a—3b; Plate 5; Plate 11; Plate 12, Figure 2 Astrocles actinodetus Fisher, Ann. and Mag. Nat. Hist., ser. 8, vol. 20, 1917, p. 430. Diagnosis.—Rays 11, not very deciduous; disk fairly large, covered with circular plates bearing one to three spinelets; genital region of ray 3.5 to 4 rin length, or about one-sixth total length of ray, and crossed by 25 to 27 pretty regular transverse arches of depressed elliptical, crenulate plates covered with a felting of minute pedicellariae and bearing small spinelets in transverse series; intervals between arches without plates or pedicellariae; lateral spine opposite alternate adambulacrals, very slender and delicate; adambulacral armature consisting of one aboral furrow spinelet with tip greatly broadened and subtriangular in form, and one subambulacral spine, those on proximal half or two-thirds of genital region with an enlarged bifid tip; mouth plates with three actinostomial spines, expanded flattened and more or less irregular in form, one aboral, modified, furrow spinelet and one suboral pointed spine; in interbrachium the first pair of adjacent adambulacral plates touch or join only at their proximal ends—are not fused the whole extent of their interradial faces, nor is there directly above them a prominent pair of first marginal plates as in Brisinga. Description —The disk is only very slightly elevated above the level of the base of rays, and the latter slopes upward to the disk without any abrupt shoulder. Sur- face of disk fairly plane. Disk plates circular, slightly elevated at middle for artic- 64406—28——3 30 BULLETIN 76, UNITED STATES NATIONAL MUSEUM ulation of one to three spinelets, these larger plates surrounded by a variable number of much smaller secondary platelets which do not bear spinelets and are entirely concealed by skin until the specimen is dried. In a specimen with R 12 mm. these platelets are numerous everywhere among the primary plates, but in an example with R 10.5 mm. the primary plates are separated by bare integument, and the sec- ondary plates are beginning to appear here and there in this integument. Ordinarily there are one to three delicate sharp spinelets, about 1 mm. long, to each plate, these appearing blunt before being dried on account of the membranous investment. The groups of spinelets are spaced 0.5 to 1.5 mm. apart and about 25 to 28 of these groups can be counted from one side of the disk to the other. In some specimens half the primary plates, or even more, have but a single spinelet. The spinelets as a conse- quence appear to be less numerous and more widely spaced. Attached to the plates and sometimes to the base of the spines are one to five minute pedicellariae. Madre- poric body on edge of disk small, prominent, with a very few deep striae. Rays with short, swollen genital region, the length of which is about 3.5 to 4 r, or on one perfect ray about one-third the length of ray. The disk plating continues upon the radial region of the ray as far as the fourth adambulacral, beyond which the plates are in pretty regular transverse arches, covered with an even felting of minute pedicellariae. The plates are irregularly elliptical, oriented transversely, the edges more or less crenulate in old specimens, and the plates are broadest on the abactinal surface, narrowing conspicuously upon the sides of ray. The interval of bare skin is therefore wider (1.5 mm.) on the sides of the ray, than at the crest of the arches (0.5 to 1.mm.). The plates seem to increase in size with age, the arches being rela- tively broadest in the largest specimens. The arches taper to a point where they join the small lateral plates, and alternate arches end before reaching the corresponding adambulacral, as there is no lateral plate for them to meet. The plates are thin and almost flush with the general surface, except along the middle line where there is a row of two to five sharp, small, spinelets articulated to an incipient ridge in old specimens. The arches do not form such prominent costae or ribs as are commonly found in Brisinga. Beyond the costal area the ray is crossed by fairly broad, frequent bands of minute pedicellariae, one opposite each adambulacral plate. Lateral plates small, situated opposite alternate adambulacral plates, beginning with the fifth to seventh. Lateral spines very slender and fragile, and on the outer part of ray attain a length of 21 mm., or about the length of 10 adambulacral plates, but on the genital region they are short. The first spine is about one plate long, and the seventh about 3.5 plates (6.5 mm.). Adambulacral plates rather short with deeply excavated furrow margin. Arm- ature consists of one aboral furrow spinelet and one subambulacral spine. The former extends half-way across ray and has a very unique form. The end of the spinelet flares so as to form a flattish triangluar plate, or else it is two-pronged. This tip fits snugly against that of the opposite spinelet, and at the same time the tips of the spines of the same series nearly meet on account of the flaring end. As a result the ends of the spinelets form a series of valves which completely or nearly completely fill in the spaces around the tube-feet, almost as if they had been poured in and allowed to harden. This applies to the genital region, beyond which the curiously modified tip becomes less prominent as one proceeds along the ray, until on the outer attenuate ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS——FISHER 31 portion the spinelets are normal or only slightly clavate, or spatulate. Sometimes far along ray there are two aboral furrow spinelets. The first 12 or 15 subambulacral spines have a variably modified spatulate truncate, grooved, or incipiently bifid tip, most pronounced on the third to the ninth or tenth, beyond which as the spines lengthen the tip becomes rapidly smaller. From the twelfth to about the twenty- fifth the spines are merely slightly and decreasingly capitate. On the genital region the subambulacral spines are about 2.5 to 3 plates in length. On the outer part of the ray those on plates to which a lateral plate and spine are fastened are short and slender (1.5 to 2 plates long) while on alternate plates the subambulacral is fastened slightly more upon the actino-lateral face of the plate and measures 3.5 to 4 plates in length (as compared to the lateral spine which equals 9 or 10 plates). The rays are separated nearly to the mouth plates; only the proximal ends of the first adambulacral plates are in contact. The outer part of the mouth plates does not separate the first pair of adjacent adambulacrals but extends upward behind the joined inner ends of the adambulacral plates to meet the lower end of the inter- radial plate. These upper ends resemble a pair of independent plates. Mouth plates with a modified spinelet, like the adambulacral furrow spinelets, at the outer furrow end of plate, and another at the inner actinostomial end, the two enclosing the first tube-foot. Forming a series with the latter spinelet on the actino- stomial margin are two others, variously expanded and leaflike in form, but bent sharply toward the furrow mouth. The innermost is near the median suture and is sometimes quite small. The second is intermediate in size and lies parallel to that which guards the mouth of the furrow. The amount of expansion of these curious spinelets varies a good deal and their form is often irregular and bizarre. On the outer half of each plate is a tapering, pointed, suboral spine equal to the first 3 or 3.5 adambulacral plates in length. The articulation surface of the ambulacral plates (second pair), where the ray has been broken off from the disk, is small, deeply notched above and below. The articulation surface is not sharply marked off from the two processes below, as in Brisinga. Gonads: The ovaries are each a single slender sac about 2 r in length which opens by the proximal end on the side of the ray, nearly 1 r from the interbrachium. There are two ovaries to each ray. The testes, two to a ray, are many-lobed bodies which have a single opening about 1 r from the interbrachium. Type.—Cat. No. E. 1416, U.S.N.M. Type-locality Station 2859, off British Columbia (55’ 20’’ N., 136’ 20’” W.); 1,569 fathoms, gray ooze; bottom temperature, 34.9 F.; 13 specimens. Suborder ASTERIADINA Fisher Family ZOROASTERIDAE Sladen Zoroasteridae SLADEN, Challenger Asteroidea, 1889, p. 416.—Fisner, Ann. Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 387; Bull. U. 8S. Nat. Mus. 100, vol. 3, 1919, p. 470.—Curark, Mem. Mus. Comp. Zodl., vol. 39, No. 3, 1920, p. 94. Deep-water Forcipulata having a small disk and slender, subcylindrical, often long rays, the plates of which are disposed in regular, usually closely juxtaposed, 32 BULLETIN 76, UNITED STATES NATIONAL MUSEUM longiseries; pedicellariae of the straight sort only, the crossed being absent; spinelets delicate and slender, usually in regular longiseries, sometimes absent; alternate adambulacral plates (in one genus, all) with a prominent spiniferous projection into furrow. Starfishes of the Zoroasteridae are abundant on muddy bottom in deep water off the west coast of the United States, and form a very characteristic element of the fauna. While the species are not numerous, individuals swarm in some localities, judging by the results of dredge hauls. Further study of Myxoderma, first proposed as a subgenus, has shown it to be very distinct from Zoroaster. The capture of large examples of Cnemidaster wyvillr ® in the Gulf of Tomini, Celebes, not a great distance from the type-locality, has thrown a new light upon a genus which was based upon a young and inadequate specimen. Mammaster is closely related to Cnemidaster. Clark (1920, p. 96) has found that in Mammaster the first carinal plate, just distal to the primary radial is conspicuously enlarged and is larger than the adjoining second marginals. Mammaster also lacks adradial plates. The genus is monotypic and is found in the West Indies and Gulf of Mexico. Clark (1920, p. 100) has prepared a very useful synopsis of the species of Zoroaster. This paper, furthermore, contains a good review of the family. SYNOPSIS Os THE KNOWN GENERA OF ZOROASTERIDAE - a!. Dorsal surface not devoid of spines and not covered with a smooth tough membrance in sharp contrast to the spiniferous of squamiferous actinolateral regions. b!. Superambulacral plates absent, no conspicuous buttress extending from the upper enlarged end of the first two pairs of ambulacral plates to the body-wall at the interradial angle. c!, All adambulacral plates carinate on the furrow face. Genotype, Prognaster grimaldit ETT a ee Prognaster !° Perrier. c?. Adambulacral plates alternately carinate and noncarinate. d'. Rays long, slender; disk small; abactinal, marginal, and actinolateral plates arranged in regular longitudinal lines along ray, a series of adradial plates being always present; all but the median radial or carinal, which are larger, form also transverse series; plates are covered with small, papilliform, skin-covered spinelets, and most of them bear an enlarged spine; papular areas generally very small but sometimes nearly as large as plates; straight pedicellariae present; actinolateral plates in three to five series, the upper subequal to the inferomarginal plates; superomarginal plates not conspicu- ously larger than the inferomarginal plates. Genotype, Zoroaster fulgens Thomson. Zoroaster Thomson. d?. Plates of ray arranged in regular longitudinal series, the carinal plates the largest; abac- tinal and marginal plates armed with fairly large, skin-covered scales which mask all plates except some of the disk-plates and the carinal series along ray; no pedi- cellariae; actinolateral plates, in two or three series, much smaller than infeauienee nals; superomarginal plates much larger than inferomarginal plates. Pholidaster squamatus Sladen Genoky De, ee en See ee all te ee Pholidaster Sladen. ® Fisher, Bull. U. S. Nat. Mus., 100, vol. 3, 1919, p. 480.—Clark, Mem. Mus. Comp. Zodl., vol. 39, No. 3, 1920, p. 97 10 Prognaster Perrier, ‘Comptes rendus,”’ vol. 112, 21, No. May 5, 1891, p. 1226. Type P. grimaldié Also cece des campagnes scientifiques du Prince de Monaco,” fasc. 11, 1896, p. 22, pl. 2, figs. 1, la-b. Inthe migantiis Rows described Pro, nate as a new genus with P. longicauda, new species, ostensibly as type (Expéd. scientif. du “Travailleur”” at du “Talism: 104, p. 119). This species does not seem to be congeneric with grimaldii, which, of course, is the genuine genotype ape : ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 33 b?. Superambulacral plates present; a conspicuous buttress, the specialized first superambulacral plate connects the upper end of the first two ambulacral plates with the bodywall at interradial angle. c!, Adradial plates present; two series of papular areas between the carinal and superomarginal plates, the latter never conspicuously enlarged nor overlapping the carinals. Geno- type ;orgastersaceulaius Wishere.- 2) == 2-5 Soe Myzxoderma Fisher- c?. No adradial plates; one series of very small adradial papular pores; superomarginal plates of two sizes, alternately larger and smaller, overlapping the carinals strongly and dominating these plates, which are sunken below the level of the superomarginals. Genotype, Bythiolophus acanthinus Fisher------- cpl cs tore ne Bythiolophus ' Fisher. a’. Abactinal plates of disk, the carinals, adradials (when present), marginals, and sometimes one series of actinolateral plates devoid of spines or any conspicuous armature, but mostly smooth and covered with a tough membrane of variable thickness, often partly obscuring the plates; two to four lower series of actinolateral plates covered with squamiform fleshy spinelets and sometimes a conspicuous appressed spine; superambulacral plates present, the first conspicuously enlarged into a buttress connecting the upper end of the first two ambulacral ossicles with the body wall. b!. With a series of adradial plates more or less well developed; first carinal scarcely or not at all larger than the first marginals which are evidently larger than the second; four or five series of actinolateral plates. Genotype, Cnemidaster wyvilli Sladen_Cnemidaster Sladen. b?. Adradial plates absent, the inner lobe of the superomarginal plates overlapping the carinal plates; first carinal plate, just distad to primary radial, conspicuously enlarged, larger than the adjoining second marginals which are very much larger than the first ones; three series of actinolateral plates with rudimentary fourth series in large specimens. Genotype, Zoroaster sigsbees Lermier se oe oe ne ee ee ee eae Mammastier Perrier. Genus ZOROASTER Wyville Thomson Zoroaster WYVILLE THomson, The Depths of the Sea, 1873, p.154. Type, Z.fulgens Thomson. For key to species: Clark, Mem. Mus. Comp. Zodl., vol. 39, No. 3, 1920, p. 100. Diagnosis.—Zoroasteridae lacking superambulacral plates, with small disk, com- posed chiefly of primary apical plates, and long slender rays made up of a carinal series of four to six lobed plates, overlapping on either side a regular adradial series,: these followed by two regular series of four-lobed or lozenge-shaped marginals and three or four series of subsimilar actinolateral plates, imbricating so that the lower and the adoral margins, or lobes, are free and overlap the aboral and upper margins of neighbor- ing plates; adradials, marginals and actinolaterals also forming transverse series; most of the plates normally with a central spine, and spinelets; papular areas very small, in the junction between four plates; adambulacral plates short, band-like, of two sorts: (1) prominent plates projecting into furrow forming a sort of carina bearing a transverse series of three to six spines, the inner one or two frequently bearing pedicellariae, sometimes quite large; (2) alternating with these prominent plates are much narrower noncarinate plates bearing one or two transverse series of two spines each, or a group of three with or more often without pedicellariae; pedi- cellariae usually present on abactional and lateral plates; tube feet in four series 11 Proc. Biol. Soc., Washington, vol. 219, 1916, p. 31. Bull. U.S. Nat. Mus. 100, vol. 3, 1919, p. 484, pl. 135, figs. 1, 1a-c; pl. 189 figs. 1,2. In the description adradial plates should read superomarginal. The corrected diagnosis is as follows: In general structure resembling Zoroaster, except in the absence of adradial plates; in presence of superambulacral plates; in the specialization of the first superambulacral plate as a conspicuous buttress running from the body wall at the interradius to the upper end of the first ambulacral ossicle, and in the arrangement of the abactinal skeleton. The superomarginal series is more prominent than the carinal consisting of alternately larger and smaller, transversely elongated plates, the larger of which overlie the lateral third of the carinals; both sorts strongly overlap the upper end of the inferomarginals. Two series of marginal and five series of actinolateral plates. Adambulacral plates as in Zoroaster. 34 BULLETIN 76, UNITED STATES NATIONAL MUSEUM proximally, usually becoming two distally; ampullae when deflated with two lobes , gonads two to a ray, attached a little distance from interradial angle on level with marginal plates. KEY TO THE SPECIES AND SUBSPECIES OF ZOROASTER HEREIN DESCRIBED a. With four series of actinolateral plates on proximal part of ray; dorsolateral and intermarginal papular areas very small with normally one papula each; inferomarginal and actinolateral spines slender, closely appressed. b!. Superomarginal spines very slender, appressed; no adradial spines; 10 carinal plates cor- respond to 14 adradial and 14 superomarginal plates; fourth or lowest actinolateral series extending far along ray; plates of first two actinolateral series as broad as inferomar- ginals; adradial plates broadly overlapped by adjacent SeTIGS.a= fo2— ophiurus Fisher b?. Superomarginal spines more robust, often bristling; an incomplete series of adradial spines; 10 carinal plates correspond to 19 adradial and 19 superomarginal plates; fourth or lowest actinolateral series short (one-sixth length of ray); plates of first actinolateral series, only, as broad as the inferomarginals; adradial plates exposed (about 50 per cent broader) cite Yate Sees sveh Sus satu eee sees Lee eee SSS actinocles Fisher. a?. With three series of actinolateral plates; the two dorsolateral and the intermarginal series of papular areas with two to four papulae, the areas rather large; all spines rather long and bristling. b!. No large pedicellaria regularly on the second spine of prominent adambulacral plates OE pet aR aa IO Ate NaS IE RE evermanni Fisher. b?. A large pedicellaria regularly present on the second spine of prominent adambulacral plates el ek uy yt yl ee np apes a eas = mordax Fisher. ZOROASTER OPHIURUS Fisher Plate 13, Figures 1, la-le; Plate 17; Plate 18, Figures 2, 3 Zoroaster ophiurus Fisupr, Bull. Bureau Fisheries, 1904, vol. 24, June 10, 1905, p. 315; Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 390.—H. L. Crarx, Bull Amer. Mus. Nat. Hist., vol. 32, art. 8, July 9, 1913, p. 199; vol. 48, art. 6, 1923, p. 152; Mem. Mus. Comp. ; Zodl., vol. 39, No. 3, 1920, p. 102. Diagnosis Belonging to the slender-rayed relatively delicate carinatus group. Rays five. R 140 mm.;r10mm.;R=14r. Breadth of ray at base, 11 mm. Disk small and convex; rays very long and slender, tapering from a narrow base to an attenuate extremity. Abactinal surface of rays strongly convex, with a fairly promi- nent median radial ridge. Adradial plates sunken, rather inconspicuous, nearly covered by adjacent series; four series of actinolateral plates; marginals and actino- laterals each with a very slender needle-like spine; numerous prominent pedicellariae; miliary spinelets slender, curved, spaced, not so long on rays as the pedicellariae; carinal plates with a short blunt, subtruncate tubercular spine, much heavier than the lateral spines and usually more or less grooved or scored at the end. Description—Plates of abactinal surface of disk rather convex, the primary radials and basals being most prominent. They are covered with delicate and slender sharp spinelets, about 1 mm. in length, distinctly spaced, among which are scattered numerous straight pedicellariae, larger than the spinelets, and, of course, much more robust. The median radial series of plates is more prominent than the rest, and each bears, on a central prominence, a thimble-shaped tubercle. The abactnnt and lateral faces of the ray are gradually confluent by a well-rounded margin, the supero- marginal plates not being prominent in any way. Between the sapere men and adambulacral plates are five longitudinal series of exactly similar plates—an infero- ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 35 marginal and four actinolateral series—and all are precisely similar to the supero- marginals. On the outer portion of ray the actinolateral series are successively reduced to three, two, and finally at end of ray toone. Each of these plates, including ‘the marginals, bears a very slender, delicate, sharp spinule, which increases in length toward the furrow, that on the proximal superomarginals being 2 mm. in length, and that nearest the furrow in the same transverse series, nearly 4 mm. The general surface of the plates is covered with very delicate, short, spaced, often curved spine- lets, and there are one or two rather prominent pedicellariae to each plate, forming fairly regular longiseries along the ray, between successive series of plates. The median radial plates bear two to five pedicellariae each. Papulae inconspicuous, one or two to the pore, usually one. Papular areas very small. The prominent adambulacral plates bear a transverse series of three to five spinelets. The inner two are short, stout, and pointed, and are borne on the furrow projection. The inner has a terminal membranous expansion bearing six or eight pedicellariae of graduated sizes. The second bears one similar much larger pedicellaria or occasionally two, near the base of the spinelet. The next or first subambulacral spinelet is larger, and is slender and pointed, the two following being successively shorter. On the outer part of ray, only two subambulacral spinelets are commonly present, and the second furrow spinelet is often missing. The alternate, nonpromi- nent, plates have a small furrow spinelet, bearing one or two small pedicellariae, situated near the adoral edge, and on the actinal surface a transverse row of two spinelets very similar to those of the prominent plates. A large pedicellaria some- times stands at the outer end of the series. Madreporic body convex, subtubercular, circular, situated 7 mm. from center of disk. Anatomical notes—There is an incipient dorsal stomach pentagonal in outline, and a saccular stomach proper with a short rounded lobe in each ray. From the corners of the dorsal division depart the two slender hepatic coeca which extend 0.6 the length of ray. Interradially, between the points of departure of the hepatic coeca, the dorsal stomach is outlined by a prominent fold. The radial sacs of the ventral stomach are attached to the prominent knob of the first two pairs of ambula- cral ossicles by numerous strands. Intestinal caecum consists of three tubular structures, 10 to 15 mm. long, springing from a common center. The opening from this small central chamber into stomach is prominent. Gonad long tubular with a few irregular lateral branches; it opens intermarginally at base of ray a short dis- tance from the interradius. Interradial septum rudimentary, membranous. Ampul- lae double; that is, consisting of two divergent divisions springing from the central portion of the pore. No Polian vesicles; Tiedmann’s bodies present. No super- ambulacral ossicles present. (Specimen from station 2919 examined.) Variations.—The largest specimen from station 2919 is only slightly bigger than the type, but the rays are noticeably broader and the adradial series of plates is not quite so much encroached upon by the neighboring series as in the type. The lobes of the superomarginal and carinal plates do not come within 0.8 to 1 mm. of touching. R 155 mm.,r12mm.; breadth of ray slightly beyond base, 12 mm. The example from station 4765 has the following large dimensions: R 178 mm., r 11 mm. R=16 r; breadth of ray, a little beyond base, 14 mm. This specimen is 36 BULLETIN 76, UNITED STATES NATIONAL MUSEUM fairly typical with the exception that there are fewer adambulacral pedicellariae than in California examples; particularly the big pedicellaria on the second furrow spine is wanting except on a relatively few plates at the base of the ray. Rarely spine two carries a group of three or four small pedicellariae like those (four to six in number) on the first or innermost spine. Except at the very base of ray, the tube feet are two-ranked. ‘The marginal and actinolateral spines are delicate, slender and sharp as in the type, 4 to 6 mm. long at base of ray and increase in diameter as the furrow is approached, those of the lowermost two rows being at the base about twice as thick as the marginal spines, as well as about 1 to 1.50 mm. larger. The carinal tubercles are coarse, 1 to 1.25 mm. long, slightly swollen above the base (about 0.75 mm. in diameter), truncate or blunt, the end sometimes finely striated longitudinally. The carinal plates form a prominent angular ridge, and the adradials are appreciably sunken. The lobes of the superomarginal and carinal plates broadly overlap the adradials and are separated by 0.75 to 1.25 mm. space at the base of the ray. The pedicellariae slightly exceed the miliary spinelets in length, and are conspciuous, being about 1.25 to 1.50 mm. long; but owing to the investment of the spinelets being a little thicker than in southern specimens the pedicellariae do not appear to be quite so prominent. The spinelets are slender, delicate, curved at the base , and slightly compressed so that they appear to be saber-shaped in many cases. They average slightly over a millimeter in length. The papular areas of the dorsolateral surface frequently have two papulae; those of the four lateral series, one each. Type.—Cat. No. 22,345, U.S.N.M. Type-locality —Station 4387, off San Diego, Calif.; longitude of Point Concep- tion, 32° 32’ 40’’ N., 118° 04’ 20’” W.; 1,059 fathoms, green mud. (Albatross, 1904.) Distribution.—F rom Bering Sea and off southern California; 989 to 1,217 fathoms, mud and fine black sand. Temperature range, 35.2° to 38° F. Recorded by Clark (1913) from 879 to 1,101 fathoms off Ballenas Bay and San Rosario Bay, Lower California; bottom temperature, 37.3° and 38.1°. Specimens examined.—Six; one from type-locality: Station 2919, 32° 17’ N., 119° 17’ W. (off San Diego, Calif.); 984 fathoms, gray mud; bottom temperature, 38° F. (Coll. U.S.N.M.); four specimens. Station 4765, 53° 12’ N., 171° 37’ W. (43.5 miles northwest of west point of Yunaska Island, Aleutian Islands); 1,217 fathoms, fine black sand; bottom tempera- ture, 35.2° F. (Albatross, 1906); one specimen. Remarks.—Zoroaster ophiurus belongs to the carinatus group of species, in which the rays are very slender, long, and pointed; the carinal series of plates is prominent and more or less carinate ; and, particularly, the adradial series is inconspicuous, much narrower than either the carinal or the superomarginal and is strongly en- croached upon by both. No matter how large the specimen becomes, the adradials do not equal the size of the superomarginals. The reduction of the adradials is more pronounced in Z. ophiurus and in Z. carinatus philippinensis than in Z. spinulosus of the Hawaiian Islands. Z. ophiurus differs from Z. spinulosus in having the adradial series of plates so nearly covered by the carinals and superomarginals that the lobes of the two latter Tear VO EiaUTLEMe oct Eauiviesé ties tees ee wice as large as in spinulosus, more ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 37 numerous, and the miliary, or secondary, spinelets are conspicuously longer. Even the primary spinules are longer, but the difference is less well marked. Z. carinatus philippinensis lacks the carinal series of tubercles, and the slender acicular supero and infero marginal spines. The miliary spinelets of the Philippine species are more numerous, more compactly placed, and are appressed to the plates. They are less slender and more squamiferous than in ophiurus. The body pedicellariae are incon- spicuous Two species from the Pacific Ocean south of the United States must be compared with ophiurus; these are Z. hirsutus Ludwig,” station 3415, south of Acapulco, Mexico 1,879 fathoms, and Z. magnificus * Ludwig, station 3360, Gulf of Panama, 1,672 fathoms. Although Ludwig separates these species in his text by the description of Z. (= Cnemidaster) nudus, the two are very similar in appearance. Both have the long slender rays of the carinatus type, but the adradial plates are not sunken, or subservient to the carinal and superomarginal series, although the latter slightly overlaps them. In Figure 146 “ the adradials are shown as being slightly smaller than the superomarginals. In a ray of the cotype which I have, they are more often slightly larger on the basal part of the ray. Figure 168 shows the arrangement of plates in Z. hirsutus. These two species constitute a magnificus type, differing from the carinatus type in the greater size of the adradial plates, although in general form and in the small size of the papular areas resembling the carinatus type. Z. magnificus differs from hirsutus in having a few relatively large (2 mm.) abactinal and lateral pedicellariae and three series of actinal intermediate plates. In hirsutus there are four series of plates between the inferomarginal and adambulacral plates, and numerous small pedicellariae. Z. ophiurus differs from these two species in respect to the adradial plates, which, as noted above, are much less conspicuous. In addition it is separable from magnificus by reason of the presence of a fourth actinal series of plates and the absence of the particularly large pedicellariae, relatively few in number. On the other hand, the pedicellariae are larger and more numerous than those of hirsutus, the carinal plates are more prominent and have longer lateral lobes. ZOROASTER ACTINOCLES Fisher Plate 13, Figures 2, 2a—2c; Plate 18, Figure 1; Plate 20, Figure 1 Zoroaster actinocles Fisurer, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 390.—C.Lark, Mem. Mus. Comp. Zoél., vol. 39, No. 3, p. 101. Diagnosis —Rays five. R 161 mm., r 11 mm., R=14.6 r; breadth of ray at base, 13 mm. Rays slender, evenly tapered to the extremity, which is capped by a relatively large terminal plate; disk elevated at center; carinal ridge rather promi- nent. Resembling aslender-rayed Z. fulgens but differing in having the plates of the second, third, and fourth actinolateral series smaller, the fourth series being rudimen- tary; in having slenderer superomarginal spines (decidely slenderer than the carinal spines), fleshier spinelets, relatively larger carinal plates, never but one actinolateral 13 Ludwig, Mem. Mus. Comp. Zodl., vol. 32, 1905, p. 172, pl. 28, fig. 161, 162; pl. 29, fig. 168. 13 Ludwig, idem, p. 159, pl. 26, figs. 146-148, pl. 27, figs. 149, 150. 4 Ludwig, idem, vol. 32, 1905. i Ludwig, idem, vol. 32, 1905. 38 BULLETIN 76, UNITED STATES NATIONAL MUSEUM spine to a plate; in having a decidedly larger terminal plate, and a large pedicellaria on the second (from furrow) adambulacral spine. Description.—The carinal ridge is carried to center of disk, the central, radial, and basal plates of which bear a stout spine similar to those on the ray. All the plates are perceptibly convex and are covered closely with papilliform blunt pulpy spinelets like those of the rays. The pedicellariae are few and only a trifle longer than the spinelets. Papular pores and papulae (single) very inconspicuous. The ray slopes off rather steeply from the carinal ridge like the roof of a house; there is a perceptible angle between this dorsolateral surface and the slightly convex or rounded lateral surface. Each carinal plate is convex, and the series as a whole forms a ridge rising above the general level. Carinal spines robust, somewhat swollen and furrowed, bluntly pointed to subtruncate. The adradial plates are fairly well exposed and a few at the base of the ray bear a conical spine 2.5 mm. long. Superomarginal spines robust but slenderer than the carinals, tapering, pointed, — about 2.5 to 3 mm. long, normally bristling as in fulgens. Below these is a longi- tudinal series of similar inferomarginal spines, then four series of sharp actinolateral spines, those of the two upper series being the longest. The fourth series extends only a short distance; over the greater part of the ray there are either three or two series only. The general surface of the plates is covered with close-set pulpy papilli- form spinelets which are contiguous and completely hide the surface of the plates. These are much thicker than the sheathed spinelets of Z. ophiurus from the same station and show evidence of having been slimy in life. When dried, the calcareous part is seen to be very delicate and sharp and 0.6 to 1 mm. long. The spinelets then appear to be well spaced. The carinal plates carry upward of 50 and the adradials about 15. The pedicellariae are fairly slender, evenly tapered, a trifle longer than the spinelets, rather few and inconspicuous. They stand near the single papulae, on both dorsal and lateral surfaces. The skeleton of the ray is very compact and is characterized by exposed adradials, smaller than the superomarginals. (See pl. 13, fig. 2.) The carinals are rather long with two short rounded lobes on each side. To 10 carinals at base of ray there are 19 adradials and 19 superomarginals (=35 mm.). In a specimen of Z. ophiurus from the same station, to 10 carinals there are 14 adradials and 14 superomarginals (=26 mm.). The carinals are thus bigger in acfinocles, for in a space of 35 mm. in ophiurus there are exactly the same number of adradials and superomarginals as in actinocles. In the latter the adradials are much more exposed and thus appear to be larger than in ophiurus. In actinocles the lowest or fourth series of actinolateral plates extends only a short distance (about 22 mm., or one-sixth the length of ray), whereas in ophiurus they extend upon the outer part of the ray and bear spines. In actinocles the third series extends two-thirds the length of ray, and the second series to within about 20 mm. of the tip. If a cleaned ray of actinocles is compared with one of ophiurus of the same size, the larger actinolateral field of the latter is at once very evident. At the base of the ray in ophiurus the plates of the first two actinolateral series are quite as large as the inferomarginal plates while those of the third series are about two-thirds as large. In actinocles only the plates of the upper, or first, row are as large as the inferomarginals, and that only at the very base of the ray, for after the sixth or seventh plate of the series they become smaller than the infero- ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 39 marginals. The combined breadth of the second, third, and fourth series is only a trifle greater than the width of the first series alone. As mentioned above, after the first sixth of the ray is passed, only three actinolateral series remain. The terminal plate is relatively large, broadly elliptical, and rounded-truncate. It lacks the characteristic notch on the proximal side, or has but a slight indication of it. The plate is 4 mm. long (or the length of the last four carinal plates) and a trifle over 2.5 mm. broad. In the large specimen of ophiurus from the same station, the terminal plate is small subglobose or subquadrate, about 2 mm. long by 2 broad, the proximal margin broadly notched for a third of its length; it is about as long as the last four carinal plates, which are therefore very small. Papular pores small; there are five regular longitudinal series, with the beginnings of a sixth at the base of ray, and they also form regular transverse series. There are two dorsolateral, one intermarginal, and two actinolateral series, plus one rudimentary series. In ophiurus there are three actinolateral series plus a few pores of a fourth. Papulae solitary and small. Prominent adambulacral plates with a transverse series of five spines. The first is deep in the furrow on the apex of the projection, is slightly compressed, and has a terminal flap of tissue carrying upwards of eight small unequal tapered pedicellariae. The second is about the same length, slightly compressed, and usually carries a pedicellaria about 1.5 mm. long attached to its base. The third is tapered, bluntly pointed, and a little longer than the second, or about 2.5mm. The fourth and fifth (and sometimes a sixth) are very delicate, similar to the actinolateral spinelets, and about 1.5 mm. long; No. 5 may be lacking. The nonprominent alternate plates have a transverse series of four or five spinules, the innermost small and situated adorad out of line with the others. The second is commonly enlarged, about 1.75 mm. long, and corresponds to No. 3 of the prominent plates. The outer one or two spinelets are delicate. All spines, and particularly spinelets, are sheathed with pulpy soft membrane so that they appear unnaturally robust. The mouth plates have three actinostomial and two suboral spines. Ambulacral furrows rather narrow; tube feet in four series, crowded. No superambulacral plates. Ampullae, when empty, with two subequal lobes. Gonads two to each ray. Madreporic body quite small, situated 7 mm. from center. Type.—Cat. No. 37039, U.S.N.M. Type-locality —Station 4765, 53° 12’ N., 171° 37’ W., 43.5 miles northwest of west point of Yunaska Island, Aleutian Islands; 1,217 fathoms, fine black sand; bottom temperature, 35.2° F. (Albatross, 1906.) Distribution —Known only from the type-locality. Remarks.—As nearly as can be determined, this species is a north Pacific repre- sentative of Zoroaster fulgens, from which it differs, however, in rather fundamental ways, as enumerated in the diagnosis. Sladen is quite explicit in his description with regard to the size and armature of the actinolateral plates—the plates of the uppermost series being broader than those of the three lower (as in actinocles) but the plates of the three lower series have ‘‘usually one to three spinelets much longer and more robust than the accompanying miliary spinelets. These are naked, deli- cate, cylindrical, and taper to a fine extremity, and are generally arranged in slightly 40 BULLETIN 76, UNITED STATES NATIONAL MUSEUM oblique lines with the middle spine often more forward, and longest when three are present, near the lower margin of the plate.’’ (Sladen, 1889, p. 419.) In actinocles, the surface of two lowest series is sufficient to carry but one major spine. In acti- nocles, the prominent longer series of adradial spines of fulgens, is represented by only a few sporadic spines. I have been able to compare actinocles directly with examples of Z. diomedeae Verrill from 1,300 to 1,500 fathoms off Marthas Vineyard. Z. diomedeae is a western Atlantic representative of Z. fulgens, which it greatly resembles. As compared with actinocles, diomedeae has broader rays which are noticeably swollen proximally; stouter and more rigid superomarginal spines; the fourth actinolateral series of plates extends over half the length of the ray; while at the base there is a rudimentary fifth series of actinolateral plates; there are 17 adradial and 17 superomarginal plates to 10 cardinals at the base of ray (15 in Sladen’s figure of fulgens); the second adam- bulacral spine of prominent plates lacks a large pedicellaria; the rays are much shorter (R=about 12 r), and the terminal plate, much smaller and deeply emarginate on proximal border; some of the proximal carinal plates have three and four spines. Both Zoroaster hirsutus and Z. magnificus Ludwig, mentioned in comparison with Z. ophiurus, are of a more delicate build, with much longer and still slenderer rays, more delicate abactinal spines, fine capillary spinelets with scarcely any sheath, carinal plates only slightly convex. Z. magnificus has very large pedicellariae. ZOROASTER EVERMANNI Fisher Plate 13, Figure 3; Plate 14, Figures 1, la, 1b, Plate 18, Figure 4; Plate 19, Figure 1; Plate 20, Figures 3, 4. Zoroaster (Myxoderma) evermanni FisHEr, Bull. Bureau Fisheries, 1904, vol. 24, June 10, 1905, p. 317; not Cuarx, Bull. Amer. Mus. Nat. Hist., vol. 32, art. 8, July 9, 1913, p. 198 (= Myxoderma sacculatum). Zoroaster evermannt Fisner, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 390.—C1arK Mem. Mus. Comp. Zodl., vol. 39, 1920, p. 100; Bull. Amer. Mus. Nat. Hist., vol. 48, art. 6, 1923, p. 152. Diagnosis —Rays, five. R. 140 mm.; r 10 mm.; R=14 r; breadth of ray at base,11mm. Rays long, gradually tapering from a narrow base to a pointed extrem- ity which is capped by a small terminal plate; dorsal surface sloping like a roof from the carinate radial series of plates to the superomarginal series, which marks bound- ary between the dorsolateral and the slightly bulging lateral face of ray; disk con- vex, the abactinal surface considerably higher than carinal ridge of ray; inter- brachial angles very acute, the rays being slightly constricted at base. Character- ized by irregularly lobed, exposed, adradial plates, relatively large papular areas dorsally, very prominent carinals and marginals, prominent, bristling, acicular spines (one to a plate except adradials), numerous capillary spinelets invested in life by a soft, thick, pulpy sheath, and long bristling adambulacral spines. Description—The primary radial, basal and central plates of the disk are stellate with five, six, or seven prominent rounded lobes, and bear a central, promi- nent, rather stout sharp spine about 2.5 mm. long, articulated to a prominent boss on the plate, and the general surface of these and the other smaller disk plates is beset with distinctly spaced spinelets, 0.75 to 1.25 mm. long, some of which are pointed ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 41 others are flattened and broad at the ends. On the larger plates there are one or two pedicellariae from 0.75 mm. to 1.5 mm. in length. Although the spinelets themselves are spaced and slender, owing to the thick skin which invests them and the surface of the plate, they appear to be rather crowded. In alcoholic specimens the spinelets are thick, pulpy, subconical or slenderly ovoid, and touch one another. The sheath is rather thick also on the basal portion of the primary spines. The median radial series of plates is prominent, as is also the superomarginal series, and each bears a slender tapering sharp erect spine, about 3.5 or 4 mm. long, articulated to a prominent elevation of the plate. The superomarginals clearly mark the boundary between the sloping abactinal and the rounded lateral faces of the ray. Below the bristling superomarginal spines there are at the base of ray four (further along three, and finally two) longiseries of slender, subequal, bristling, sharp spines which also form transverse series. As on the disk, the general surface is beset with spaced, very delicate, almost capillary spinelets, about 1 mm. long, which in life are sheathed with pulpy membrane that makes them appear robust, papilliform, and fairly crowded on their own plate. Pedicellariae (0.75 to 1.50 mm.) occur rather commonly near the papular areas, or actinally on the membrane of the area, more abundantly on the abactinal than on the lateral surfaces. There are about two zones of them between the midradial and superomarginal angles, while on the sides of the ray they occur between the rows of spines. There are two dorsolateral, one intermarginal, and at base of ray 3 (further along 2, 1, and 0) actinolateral series of papular areas. In the dorsolateral areas there are usually three or four papulae (two or three on the outer part of ray); in the intermar- ginal areas, three or two proximally, and in the actinolateral areas generally one, but sometimes two on the proximal part of ray. The carinal plates usually have two prominent rounded lobes laterally (some- times one) which overlap the smaller, very irregularly lobed adradial plates. These, as shown in Plate 13, Figure 3, are a bit smaller than the mostly four-lobed supero- marginal plates. The lobes of the latter do not touch those of the carinal plates. The adradials do not bear a primary central spine (and are not visible in alcoholic specimens) but have an irregular group of upwards of 10 secondary spinelets. The other plates are four-lobed, and as the furrow is approached the plates are narrowed, and the transverse lobes are gradually shortened. In a specimen from station 4423 to 10 carinal plates at the base of ray (measuring 28 mm.) there are 15 to 17 adra- dial plates and 13 superomarginals. The adambulacral armature partakes of the bristling character of the general body armature. The prominent plates have a rather slighter keel or ridge into the furrow than usual. This bears a single vertical series of 4 slender terete tapering sharp spines plus one much smaller spinule at the outer end. Spine one (directed into or across furrow) carries a subterminal or terminal cluster of two to five small pedicellariae, or sometimes one fairly large and one or more small ones. Number two is a trifle larger; spines three and four are successively longer, four attaining 3.5 mm. at base of ray in some cases; or spine three may be the longest. The alter- nating nonprominent plates have a small spinelet on the furrow margin near the adoral border, and on the median transverse line of plate, a spine about equal to (or a bit longer than) spine four of the prominent plates, and standing almost exactly 42 BULLETIN 76, UNITED STATES NATIONAL MUSEUM in line with it. Outside of this is a slender spinelet similar to that of the prominent plates and in line with it. Ambulacral furrow narrow; tube-feet rather crowded, at base of ray arranged in two zigzag (or four) series, but in two series on outer half of ray. Tube-feet rather slender, with a small sucking disk. Mouth plates very short, pretty well hidden on account of the upward bend of the base of arms which carries the furrow dorsad. There are two sharp slender suboral spines and two spines at the narrow mouth of the furrow. One extends about halfway across and bears several pedicellariae; another much shorter, also bearing one or two small pedicellariae, extends over the actinostome. Madreporic body, 2.75 mm. in diameter, is convex, and its center is 7 mm. from the center of disk. Anatomical notes —The single stomach occupies the entire disk and sends a short rounded lobe into each ray. From the dorsal surface of this diverticulum (which is as broad as the inside of the ray) two hepatic coeca arise close together and extend three-fourths the length of ray. From the sides of the central tube branch off, in regular pinnate fashion, numerous small lobulated saccules, the whole gland being narrow to conform to the tenuity of the coelom. The inner surface of the stomach is very finely wrinkled and the walls are thrown into shallow folds. No dorsal stomach. Into the tiny intestine empties a conspicuous coecum, consisting in the specimen examined of two slender branches, one 15 mm. long, the other 3 mm. The large branch, tubular in form, lies on the dorsal part of one ray. The gonads are two to each ray, and open upon the side of the ray about 4 mm. from the inter- radial angle. The gonads consist of a single axis from which depart numerous lob- ulated branches. Interbrachial septum very small, rudimentary, membranous. Ampullae single, but distal end expanded, and if not inflated would appear to be somewhat fan-shaped. No Polian vesicles. No trace of superambulacral plates. Young.—The smallest specimen, from station 4400, has R 10 mm., and r 2.25 mm. It would be impossible to identify this correctly if it were unaccompanied by adults. The rays are already very slender, about 2 mm. in diameter at the base. There are present the carinal series, the beginning of the adradial series, the supero and infero marginal series, but no actinolateral plates. Except for the adradials, these and the large disk plates bear a relatively long central sharp spine, stoutest on the carinal series, and a few delicate spinelets. There are a very few relatively large pedicellariae, which, like the spines, are larger in proportion to the size of the plates than in the adult. There is one papula to each area. The adambulacral plates do not show any differentiations, there being a transverse series of three very delicate, long, sharp spines. Tube-feet in two series. The mouth plates are relatively large, not sunken, and separate entirely the first adambulacral plates of adjacent rays. (In the adult three pairs of adjacent adambulacral plates meet by their outer ends on the interradial line back of the mouth plates.) Like the adambulacrals, the mouth plates have a single series of three sharp spines, that at the inner end of the plates being quite small. The terminal plate is relatively prominent and bears six promi- nent sharp spines, four horizontally directed (two from end, and one on each side) and two on the ventral surface. From above the proximal end of the plate is notched or emarginate for about half its length. The distal end is rounded. This tiny star ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 43 is decidedly phanerozoniate in appearance and has not become a Zoroaster. At this particular immature stage it does not belong to any known genus. There are a number of half grown specimens with R 65 mm., which closely resemble the adult but have only two series of actinolateral plates. Type-—Cat. No. 22347, U.S.N.M. Type-locality.—Station 4400, 32° 50’ 20’’ N., 118° 03’ 30’’ W. (between San Diego and San Clemente Island), 500 to 507 fathoms, green mud; bottom temperature, 40.2 F. Distribution —The typical form is found off southern California, from San Diego to Santa Cruz Island, in 216 to 510 fathoms; including the following race, mordac, the species ranges to Washington and to 603 fathoms off southern California and 760 off Washington. Specimens examined.—Forty-two. Specimens of Zoroaster evermanni examined Bottom) Num- ae? Locality Depth Nature of bottom temper-| ber of Collection ature | species 2936 | Off southern California, 32° 49’ N., 117° 27’ 30’ W__- oo" | Mids §. 354 Re. eee 49 | 3 | U.S.N.M. 2937 | Off southern California, 33° 04’ 30’’ N., 117° 42” W_- 464 | Green mud_-..-._.__-- 46.5 | 7 Do. 4317 | 11 miles southwest of Point Loma, San Diego -_____-_ 161-510 | Green mud, fine sand_|________ | 1| Albatross, 1904, 4400 | Between San Diego and San Clemente Island_______ 500-507 | Green mud_-_______-__- 40.2 5 Do. 4423 | Between Santa Barbara and San Nicholas Island_--_| 539-216 | Gray sand, black peb- |________ | 7 Do. bles, shells. ae77 "| Off Santa Crag Islands 222s oo ees os en ccc eco eae= 447-510 | Black mud, rocks_-_-_-|__---.-- | 19 Do. ZOROASTER EVERMANNI MORDAX Fisher Plate 13, Figure 4; Plate 14, Figure 2; Plate 19, Figure 2 Zoroaster evermanni mordax Fisuer, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 391, Diagnosis.—Closely resembling Z. evermanni but differing in having more robust primary spines (which are typically also a little shorter actinolaterally), and in having on the second from inner spine of prominent adambulacral plates a large pedicellaria (or sometimes two), from 1.5 to 2.5 mm. long, and conspicuously bigger than the cluster of small pedicellariae on the furrow spine. R, 153 mm.; r,10+ mm. R= 15 r. Description.—This race is so closely similar to the type race in most respects that a description is superfluous. In a very large specimen from the type-locality the skeleton is more open, the papular areas being larger. There are 20 or 21 adradial plates and 15 superomarginal plates to 10 carinal plates. A very few adradials bear a major spine proximally, but this can not be considered a reliable character. Rather, I think, it is due to age. The prominent adambulacral plates have a transverse series of four or five spines shorter than in typical evermanni. On the furrow spine is a prominent cluster of four to eight small unequal pedicellariae (sometimes one or two enlarged); spine two is short and carries on the side a large pedicellaria resembling a miniature ibis head, the jaws being generally curved at the tip. The nonprominent plates carry a 44 BULLETIN 76, UNITED STATES NATIONAL MUSEUM small furrow spine and a larger actinal spine, with sometimes a third smaller spinule external to the latter. Type—Cat. No. 37040, U.S.N.M. Type-locality Station 3073, off Washington, 47° 28’ N., 1259 45 Wie40d fathoms, green mud; bottom temperature, 49.2° (?) 5 specimens. Distribution —From off Washington to southern California, 239 to 760 fathoms; in south only in over 600 fathoms. Specimens examined.—Station 3069, off Washington, 47° 25/ 30!” N., 125° 42’ W.; green mud, 760 fathoms; bottom temperature, 37.6° F.; one specimen. Station 3349, off northern California 38° 57’ 45’’ N., 124° 03’ 05’’ W.; 239 fathoms, black sand; bottom temperature, 44.1° F.; one specimen. Station 2980, off southern California, 33° 49’ 45’” N., 119° 24’ 30’” W.; 603 fath- oms, green mud; bottom temperature, 38.9° F.; 33 specimens. No locality, 11 specimens (label lost during earthquake, 1906). Remarks.—Although the differences which separate this race are not great, they are constant as regards the pedicellariae; the spines fluctuate a little and the dis- tinction is not very evident except on direct comparison. In the southern California examples the spines are scarcely heavier than in the typical form from shallower water, but the pedicellariae are very well developed. It is interesting that this race, or at least the differences which characterize the race, are found in specimens from 603 fathoms off Anacapa Island, southern Cali- fornia, bottom temperature 38.9°. It is probable that the high bottom temperature of 49.2° recorded for station 3073 is a misprint or a mistake; it is more likely between 38° and 39°, judging from records of neighboring stations. Genus MYXODERMA Fisher Myzxoderma Fisuer, subgenus, Bull. Bur. Fisheries, 1904, vol. 24, June 10, 1905, p. 316. Type, Zoroaster (Myxoderma) sacculatus Fisher; Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, pp. 389, 391 (genus).—Cuarx, Mem. Mus. Comp. Zodl., vol. 39, no. 3, 1920, p. 99. Diagnosis —Zoroasteridae resembling Zoroaster more closely than any other genus, yet differing in having a more open abactinal skeleton with relatively smaller carinal plates and smaller, usually trilobate, irregularly oriented adradial plates bounding good-sized papular areas often irregular in contour; differing absolutely in the pos- session of well-developed superambulacral ossicles, and especially in the development of the first superambulacral ossicle into a heavy buttress or bridge, uniting the enlarged upper end of the first ambulacral ossicle with the body wall at the interradius; gonads two to each ray and attached to side of the ray close to interbrachial angle; ampullae single, with a very rudimentary second lobe; ambulacral furrow wide proxi- mally ; tube-feet four-ranked ; three actinolateral series of plates below inferomarginals. Remarks.— Originally I included Zoroaster evermanni in the subgenus Myxoderma. A further study of more extensive material, as well as the subsequent description of a new species, Zoroaster platyacanthus H. L. Clark, has provided additional means of testing the naturalness of this group. I have greatly emended the original descrip- tion by the addition of the features which sharply demark Myzxoderma from Zoroaster, namely, the possession of superambulacral plates, and the specialization of the first superambulacral ossicle into a sort of flying buttress between the enlarged upper end ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 45 of the first pair of ambulacral ossicles and the body wall. This forms in effect an inner accessory actinostomial ring and is not found at all in true Zoroaster. Zoroaster evermanni does not possess these specialized stays, nor other superam- bulacral plates, and its adradial plates are more nearly like those of Zoroaster than those of Myxoderma. M. platyacanthum is a very distinct form and the membrane is not so thick and pulpy as in sacculatum, nor is there evidence that it was slimy in life. The name Myzxoderma is therefore in part a misnomer, although highly descriptive of the type species, sacculatum. KEY TO THE KNOWN SPECIES AND SUBSPECIES OF MYXODERMA a. Size large (R, 200 mm.), the plates and spines invested in a thick pulpy membrane, slimy in life; abactinal papular areas large, the dorsal skeleton being open and rather irregularly reticulate at base of ray; abactinal plates without accessory spinelets to any extent; actino- lateral spines pointed, tapered, sometimes somewhat flattened but never spatulate; terminal plate large, ovoid, especially conspicuous in young specimens; rays alternate distally. bt, Rays thicker and skeleton stouter; third or lowest series of actinolateral plates extending five-eighths the length of the ray; abactinal spines robust and stubby; abactinal pedi- cellariae smaller and less numerous. Bering Sea to central California__sacculatum Fisher. b?. Rays longer and slenderer, the third or lowest actinolateral series of plates extending along only the proximal third of ray; spines rather slenderer, and abactinal pedicellariae larger and more numerous. California south of Point Conception___-_---~---- ectenes Fisher. a, Size medium, the plates and spines not especially sacculate or slimy—about as in Zoroaster; abactinal papular areas with one or two papulae which do not occupy all the area; adradial plates small, more or less overlapped by the carinals and superomarginals; abactinal plates with numerous accessory miliary spinelets; actinolateral spines broad, flat, and more or less truncate; terminal plate small; rays not alternate distally. bt. Rays slenderer and longer, disk smaller; plates, especially the carinal and marginal, not broader than long; superomarginals not noticeably prominent; spines slenderer; pedi- cellariae larger. Southern California (south of Point Conception) and Lower Cali- formiaitilelt WaG: FIs Bish Os). gE SS ee SET de eee platyacanthum (Clark). b?, Rays broader and shorter, disk slightly larger; plates, especially the carinal and marginal, broader than long; superomarginals noticeably prominent, at least distally; spines more robust; pedicellariae shorter. Oregon to Central California________-- rhomaleum Fisher MYXODERMA SACCULATUM Fisher Plate 14, Figure 5; Plate 15, Figures 1, la-1c; Plate 20, Figure 2; Plate 21, Figures 2,3; Plate 22, Figures 2, 3; Plate 25, Figure 4 Zoroaster (Myzxoderma) sacculatus Fisumr, Bull. Bureau Fisheries, 1904, vol. 24, June 10, 1905, p. 316. Zoroaster evermannit CuARK (not Fisher), Bull. Amer. Mus. Nat. Hist., vol. 32, art. 8, July 9, 1913, p. 198. Myzoderma sacculatum Fisuer, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 392.— CrarK, Mem. Mus. Comp. Zodl., vol. 39, No. 3, p. 99; Bull. Amer, Mus. Nat. Hist., art. 6, 1923, p. 152. Diagnosis —Rays five. R200 mm.,r17 mm., R=11.7 1; breadth of ray at base, 22 mm. Disk convex, fairly high; rays subcylindrical, stout but slender, the base being slightly inflated, tapering thence evenly to an attenuate extremity capped by a swollen conspicuous terminal plate; rays not carinate except on outer portion, the dorsal surface proximally being evenly arched. Abactinal skeleton very open, with large papular areas containing several papulae; all plates with a short stout spine 64406—28——4 46 BULLETIN 76, UNITED STATES NATIONAL MUSEUM (on disk upwards of eight) which increases in size on the ventrolateral region; abactinal plates without miliary spinelets, which are numerous on side of ray; pedicellariae fairly numerous on abactinal surface, not particularly conspicuous. Membranous investment of spines, spinelets, and plates, thick and saccular in life, and extremely slimy. In dried specimens it is rather insignificant. Description —On the disk and proximal third of the rays the abactinal skeleton is open and reticulate and unlike that of Zoroaster. The plates have usually four prom- inent lobes on the rays by which they articulate with neighboring plates, leaving extensive subquadrate papular areas; but on the sides and ventrolateral regions of the ray the plates are more compactly placed and the papular areas are consequently smaller. The disk of large specimens is evenly convex and higher than therays. The prin- cipal plates are a cycle of five large six and seven lobed primary radial plates, farthest from center; a cycle of six-lobed primary basal or interradial plates, not quite so far. These 10 plates form a pentagon of which the radials are the corners. There is a good-sized stellate central plate, and connecting it with the radial plate, a smaller four-lobed plate whose lateral processes imbricate with the basal plate. These five plates plus the five basals make up a pentagon (usually interrupted or incomplete) within the first pentagon, the basals being the corners. The papular areas of disk are larger than those of the ray and are three and four sided. A circle of typically five immediately surrounding the central plate are the largest (7 to 10 papulae) and are somewhat broadly lozenge-shaped or kite-shaped. Outside of these are typically 10 smaller triangular meshes with five or six papulae. Outside of these a cycle of 10 triangular meshes (with five to eight papulae), a trifle larger than the foregoing cycle of 10. The carinal series of plates is fairly regular; the plates are usually four-lobed, rarely six-lobed, and are a trifle larger than the superomarginals, which are also four- lobed. Between the carinal and superomarginal series is a very irregular series of much smaller three and four lobed plates which imbricate with the processes of the carinal and superomarginal plates either directly or by means of a small intermediate ossicle. The characteristic large, irregular papular areas of the proximal abactinal surface result from these irregular adradial plates. The superomarginal series is perfectly regular and proximally the cruciform plates are a little wider than long. Below these is a regular series of subequal inferomarginal plates with slightly broader lobes. Then follow, at the base of ray, three actinolateral series, which are soon reduced to two and finally to one on outer part of ray, these forming regular trans- verse series with the marginals. The plates imbricate more and more as they near the furrow (especially in small examples) so that the papular areas are reduced in size, those below the inferomarginals (three series in big specimens) being smaller than adjacent plates. In very large specimens a fourth series of rudimentary actino- lateral plates is sometimes present for a very short distance at the very base of ray. On the outer portion of ray the extreme open character of the abactinal skeleton is largely lost, the adradial plates becoming more regular as the ray increases in tenuity. (For details of skeleton, see pl. 15, fig. 1a.) The primary plates of the disk bear upward of six or eight short, stout, subconical usually pointed spinules about 2 to 2.5 mm. long, and a very few smaller spinelets ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 47 are to be found on the abactinal surface. All the plates of the ray bear a prominent central or subcentral, stout, tapered spine, about 2 to 2.5 mm. long on the carinal plates, a little less on the adradial, 2 to 2.5 mm. on the superomarginal, about 3.5 mm. on the inferomarginal, and 5 to 6.5 mm. on the actinolateral plates. The carinal spines are generally blunt, and an accessory spinule is sometimes present. The adradial and marginal spines are a little sharper, while the actinolateral spines are quite sharp and acicular. The general surface of the abactinal plates is beset with scattered small granules and granuliform spinelets (invisible until specimen is dried) but on the supero- marginal plates spinelets begin to appear, which increase in number and in length toward the furrow, attaining a length of 2 mm. on the actinolateral plates. They are very slender, terete, and delicate. The whole surface of the plates, granules, spines, and spinelets is covered and incased by a fleshy rather jellylike membrane which is decidedly slimy in life. Especially on the spinelets is the sheath conspicuous. Each spinelet has a thick clavate, saccular sheath with a rounded tip, entirely obscur- ing the slender spinelet within. On account of the size of this pulpy sheath the actinolateral spinelets appear to be closely crowded. The primary spines are also similarly invested but the sheath is not proportionally so thick; they appear heavy, and on the actinolateral plates, flattened. This membrane shrinks rapidly with drying and in dried specimens almost disappears abactinally. Fair-sized pedicellariae (1.5 to 1.75 mm. long) are numerous on the abactinal surface, but decrease greatly in numbers on the actinolateral plates. They are found on the borders of the papular areas, usually at least one, sometimes two or three to an area. Papulae numerous, vermiform, large, usually longer than the spines. There are four or five, proximally in each of the abactinal areas (four series), finally diminishing in number to one on outer part of ray. On the sides of the ray, in the four series, there are one or two papulae. Distally there are but three lateral series of papulae, then two, then one and finally at the tip, none. The terminal plate is very prominent, cordate, with a deep sulcus on the proxi- mal side, and it is broader than the terminal, attenuate portion of the ray immedi- ately adjacent to it. It measures 4.5 mm. to 5.5 mm. long by 3.5 mm. to 4 mm. broad in fully grown specimens. The prominent adambulacral plates have a conspicuous furrow keel. Their armature is as follows: (1) On the tip of the furrow projection is a short terete spine, often curved a little furrowwards at the end, which bears a large pedicellaria (2 mm.), with curved jaws, and two or three smaller companions. The latter are sometimes absent. (2) Following this is a transverse series of three or four slightly curved, tapered pointed spines, which diminish in size as they proceed outward. The inner two are subequal, 2.5 to 3 mm. long, tapered and pointed; the outer two are about the size of the spinelets of the adjacent plates. Adorad to them is a transverse series of two similar spinelets. The alternating nonprominent plates have a small spinelet on the margin bearing a pedicellaria or sometimes two or three, and on the actinal sur- face four spines in two transverse series, about equal to the smaller spines of the prom- inent plates. The actinal spines and spinelets are sheathed by the characteristic pulpy membrane which, owing to pressure, may form a rather prominent flange along either side of the spine which takes on a blunt, lanceolate, squamiform appearance. 48 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Ambulacral furrow broad; tube-feet crowded, four-ranked, except on the outermost attenuate portion of the ray. Mouth plates small but brisingoid in shape—that is, with the actinostomial margin broadened fanwise—and bearing two short marginal spines, loaded with pedicellariae. Suboral spines two, tapering, bluntly pointed, m a longitudinal series. Madreporic body small, convex, situated near entrance to interbrachial sulcus 12 mm. from center. Anal aperture considerably to one side of center. Color in life, buffy “salmon” pink. Anatomical notes——Specimen from station 4517. The stomach is a depressed subspherical sac filling the coelom of the disk but not extending into the rays. There is no separate dorsal stomach, nor even a fold of the wall to indicate a dorsal division of the cavity. The hepatic coeca are rather thick and extend about one-third the length of the ray; their lateral branches have very numerous, crowded, short irreg- ular lobules. ‘The two coeca open independently side by side into each radial area of the stomach. Sometimes the first branch of each coecum opens independently, just dorsad to the main tube, into the stomach. The hepatic coeca and the gonads completely fill up the proximal third of the coelom of theray. From the middle of the dorsal side of the stomach departs the extremely short intestine into which open two digitiform coeca (one forked) about 10 mm. long. These two really unite into a common base before joining the intestine. The dorsal wall of the stomach is thrown into folds, which from the inside consist of radiating, ramified grooves separated by thickened glandular spaces; from the outside these grooves are raised, and the glan- dular parts depressed. Gonads massive, branched, two to each way. The gonoduct is attached to the wall close to the outer end of the first enlarged superambulacral but- tress (see below) and on a level with the upper border of the inferomarginal plates. Interbrachial septum narrow, thin, and membranous; the attached outer inter- brachial border is in the angle formed by two buttresses (which join the conspicuous knob-like proximal end of the ambulacral ridge to the interbrachial angle of the body wall). These buttresses (pl. 14, fig. 5) are really very much enlarged superambulac- ral ossicles, are compressed, and each consists of usually two large and several small pieces closely united. In each interradius a pair of these stays forms an acute angle inclosing the interbrachial septum, and (on either side of the base of the latter) a tube-foot (two in all). The superambulacral ossicles are conspicuous on the proxi- imal part of the ray and are usually in pairs to each (lowest) actinolateral plate (one to each ambulacral plate). No Polian vesicles; Tiedmann’s bodies small, spaced; ampullae single; when deflated they have a long terminally curved division toward the ambulacral ridge, and a short outer incipient lobe. Tube-feet large with a very small button or disk. Young.—The smallest specimen of the northern race measures R 58 mm., r 9 mm., R=6.4r; breadth of ray at the base, 11mm. The abactinal and marginal spines are from 2 to 3.5 mm. long and hence relatively more conspicuous than in large speci- mens. The abactinal papular areas contain one or two papulae; the adradial spines are relatively small; pedicellarize of abactinal surface few and small; the third actino- lateral series of plates just starting at the base of ray; the first does not reach the end of ray by 10 mm., and the second series stops nearly 20 mm. short of the end. The ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 49 terminal plate is very swollen and conspicuous. The large pedicellaria on the furrow spine is conspicuous. Variations. —Of two large specimens from station 4775, Bering Sea, one measures as follows: R 160 mm.;r 17 mm.; R=9.4+ 1; breadth of ray at base, 20 mm. The other measures R 147 mm.; r 15 mm.; R= 9.1 7; breadth of ray at base, 21 mm. In this example the base of ray is much more swollen than in the other. In both the the ray is shorter than in typical examples from central California and the spines gen- erally are shorter and stubbier. The proximal abactinal papular areas contain only two or three vermiform papulae instead of the typical four or five of big Californian examples. These northern examples show an accentuation of the differences which separate the Monterey Bay and northern California examples from the southern race I have called ectenes. If typical ectenes is compared with the Bering Sea speci- mens, the difference is very striking. Type.—Cat. No. 22346, U.S.N.M. Type-locality.—Station 4517, 9 miles off Point Pinos, Monterey Bay, Calif.; 766 to 750 fathoms, green mud and sand; five specimens. Distribution —Bowers Bank, Bering Sea, and off central California, undoubtedly intergrading with the southern form from off southern California. Bathymetric range from about 550 to 766 fathoms. Specimens examined.—Ten from the following localities: Station 3670, off Monterey Bay; 581 fathoms, green mud and sand; bottom temperature, 57.8° F.; two specimens. Station 4517, 9 miles off Point Pinos, Monterey Bay; 766 to 750 fathoms, green mud, sand; two specimens. Station 4540, 11.2 miles northwest Point Pinos, Monterey Bay; 551 to 389 fathoms, green mud; one specimen. Station 4565, off Farallone Islands, San Francisco entrance; 587 to 495 fathoms, blue and green mud; three specimens. Station 4775, Bowers Bank, Bering Sea (54° 33’ 30” W., 178° 44’ E.); 584 fathoms, green mud, black specks, foraminifera; two specimens. Recorded by H. L. Clark from Monterey Bay region, 475 to 659 fathoms, 37.9° to 39.9° F. Remarks.—The stomach of one specimen contained a shrimp. MYXODERMA SACCULATUM ECTENES Fisher Plate 14, Figures 4, 4a, 4b; Plate 21, Figure 1; Plate 22, Figure 1; Plate 25, Figures 5-12 Myzxoderma sacculatum ectenes FisHER, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 392. Zoroaster evermanni part, CLARK (not Fisher), Bull. Amer. Mus. Nat. Hist., vol. 32, art. 8, July 9, 1913, p. 198. Diagnosis. —Differing from typical M. sacculatum in having slenderer and longer rays; the third or lowest actinolateral series of plates is present on only a small proxi- mal portion (about a third) of each ray; abactinal spines rather slenderer generally; abactinal pedicellariae larger and more numerous. R 210 mm.; r 16 mm.; R=13 3; breadth of ray at base, 19 mm. Description—The differences between this southern race and the northern typical form are analogous to those existing between the two subspecies of Myxoderma ; 50 BULLETIN 76, UNITED STATES NATIONAL MUSEUM platyacanthum. The most evident distinctions are the slenderer rays and more delicate structure generally of the southern form. The third or lowermost row of actinolateral plates, even in the very long rayed type-specimen, extend only a third the length of the ray, and fully half of these plates are inconspicuous, being very largely covered by plates of the second row. In a comparable specimen of sac- culatum from the type-locality which has been cleaned and dried the third series extends five-eighths the length of the ray or about twice as far as in ectenes, and there is a very rudimentary fourth series, also, for a short distance beyond the interbrachial angle. The abactinal skeleton is much less rigid in very large specimens (but in medium-sized examples the difference is negligible), the adradial plates being smaller and more loosely articulated with the relatively slightly smaller superomarginal and carinal plates. The adradial papular areas contain proximally two to four papulae, mostly the higher number. The abactinal pedicellariae are conspicuous, 2 to 2.75 mm. long, and are sometimes longer than the conical spinules, which are relatively to their length much thicker than in medium-sized examples. In the latter the pedicellariae are much thicker than the spinules, and these are in turn much slenderer than in medium-sized examples of true sacculatum. In other words, the spine differ- ences are more marked in smaller specimens. In the type the lateral spines are decidedly flattened and the longest are about 5 to 6 mm. They do not occur on every plate, certain plates being skipped (as in sacculatum). The spines have a thick sheath. On the abactinal surface the spines, pedicellariae, and papulae are so nearly of the same length that the surface seems to be covered with nearly uniform close-set papillae. The pedicellaria on the furrow spine reaches a length of 3 mm., has unequal jaws, the ends being bent so as to greatly resemble a miniature bird’s head with an unusually large ibis-like beak. Young.—There is a very complete series of young mostly from station 4425, ranging from R 11mm. (PI. 25, figs. 5-12.) The most conspicuous feature is the relatively huge terminal plate, of a rather broadly oval contour, deeply notched adcen- trally, and bearing on the ambitus eight radiating sharp relatively long spines (usually broken). This plate is 3 mm. long (R 11 mm.) or one-third the length of ray measured on the side, and 2.25 mm. in diameter; the longest terminal spine is about 2 mm. Relative to length of ray, the marginal and carinal spines are much longer than in the adult, and relatively large pedicellariae are already numerous. There is one actinolateral series of plates. The adradial plates are largely covered by the two adjacent series. ~The adambulacral plates are not yet differentiated into two sorts, and they carry a transverse comb of four or five relatively long spinules, the series alongside of the furrow reminding one of the subambulacral combs of Solaster. Tube- feet in two series and with relatively much larger disks than in adults. ' In a specimen with R only 18 mm., differentiation of adambulacral plates is progressing, and relatively large pedicellariae have appeared on the furrow spines. A second series of actinolaterals is present and the numerous abactinal pedicellariae are relatively very large. An example of the size of R 80 mm. is notable for its numerous large pedicellariae, relatively much slenderer spines than in typical sacculatum, and for already having ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 51 papular areas big enough to contain three papulae, proximally. There are three series of actinolateral plates proximally. ~ Type—Cat. No. E. 1417, U.S.N.M. Type-locality—Station 5694, southwest of Santa Cruz Island, Calif., 640 fathoms. Distribution —Off southern California, from the vicinity of Santa Cruz Island to Los Coronados Islands, and from about 500 to 1,100 fathoms; bottom temperature, 38° to 38.9° F. Specimens examined.—Seventy-two. Specimens of Myxoderma sacculatum ectenes examined Sta- F F Bottom) Nr of ear Locality Depth Nature of bottom _|temper-; speci- Collection ature mens 2919 | Off San Diego, Calif-._....---------------------- 984 | Gray mud-_---._-__.._ 38° 1] U.S.N.M. 2923 eon at SLO et ee eee 822 | Green mud_-____--__..- 39° iz Do. 2929 |..--- SL ees pee mies ate team aera 623 |----- DO Rene eee nen ee eens 1 Do. 2980 | Southeast of Santa Cruz Island_-------.-..-.--- 603 |_-.-- aot Ate. te 38. 9° 1 Do. 4380 | Off Los Coronados Island_-_-....--..---.-------- 530-618 | Green mud, gray sand_|_____.__ 1 | Albatross, 1904 4425 | Between Santa Barbara and San Nicholas Green mud, fine sand, | agland = Soo ee ee eS 1, 100-1, 084 Plobogerinas bees 53 Do. 4427 | Off Santa Cruz Island_----------_-------------- 447-510 | Black mud_-__-------.-|_-_-.._. 1 Do. 4428 |____W CC ee ee Sees See ae ee Se pe ee 764-981 | Green mud--.--------|_--...-. 5 Do. 5694 | Southwest of Santa Cruz Island_____--..-------- BAU an a eee ee ee a 1 | Albatross, 1911. 5695 |--..-. 1 eee ee eee ec esa OOS en nese eee ee 38, 9° 1 Do. Remarks.—A species which is related to this form is Myxoderma longispinum (Ludwig),!° the type of which was dredged at station 3435, Gulf of California, 859 fathoms, brown mud, bottom temperature, 37.3° F. Other specimens were taken east of the Galapagos Islands and from the Gulf of Panama, 782 to 1,322 fathoms. The largest specimen examined by Ludwig had R 29 mm. I have before me a specimen from the type-locality with R equal to 28 mm. I have also examined the type. All the specimens are, of course, very immature and no new species should have been founded upon such young material. I have examined the cotype for the superambulacral plates and find them present, the first large super- ambulacral buttress being well developed. M. longispinum is not at all the same species as I. sacculatum ectenes. I have compared specimens side by side and the following differences are readily detected: longispinum has still slenderer rays (see Ludwig, pl. 14) capped by a much smaller terminal plate which has a deeper adcentral notch and is about half as broad and a fourth shorter than that of ectenes. The abactinal pedicellariae are few and less than half as large as those of ectenes, while the median radial plates are more carinate and their spines fully twice as long as the carinal spines of ectenes. The furrow pedicellaria is smaller than in ectenes. The narrowness of the outer half of ray is expecially notice- able. 16 Zoroaster longispinus Ludwig, Mem. Mus. Comp. Zodl., vol. 32, July 17, 1905, p. 180, pl. 14, figs. 71-74; pl. 29, figs. 169-170. 52 BULLETIN 76, UNITED STATES NATIONAL MUSEUM The young of M. platyacanthum of comparable size have much thicker rays, shorter spines, numerous abactinal miliary spinelets, broader furrows, and four- ranked tube-feet. MYXODERMA PLATYACANTHUM (H. L. Clark) Plate 15, Figure 3; Plate 16, Figures 2, 2a; Plate 23, Figure 2; Plate 24, Figure 1; Plate 25, Figures 1, 2 Zoroaster platyacanthus H. L. CuarK, Bull. Amer. Mus. Nat. Hist., vol. 32, art. 8, July 9, 1913, p. 199, pl. 44, figs. 1 and 2. Myzxoderma platyacanthum Fisuer, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 392.— Cuarx, Mem. Mus. Comp. Zoél., vol. 39, No. 3, 1920, p. 99; Bull. Amer. Mus. Nat. Hist., vol. 48, art. 6, 1923, p. 152. Diagnosis —Rays five. R 96 mm.; r 10.5 mm.; R=9 r; breadth of ray at base, 12 mm. (Specimen from station 4321; the type measures R 67 mm.; r 9.5 mm.; r=7 r.) Disk small, usually flat-topped or slightly sunken in middle; rays convex, without a carinal ridge, so that the dorsum has a somewhat flattened appear- ance; rays slender, nearly parallel-sided to near the end which is not attenuate; abactinal spines and spinelets sharp, rough, bristling, rather short; actinolateral spines bristling, broad, and flat; especially characterized by open skeleton, large papular areas, small adradial plates, flattened actinolateral spines, an adradial series of primary spines, broad furrows, four-ranked tube-feet throughout, and super- ambulacral plates. Description —Primary plates of disk not especially conspicuous, stellate, the skeleton coarse with relatively large meshes containing one or two large papulae which do not occupy all the area. Spines, spinelets, and pedicellariae as on rays. Dorsal surface of ray not carinate, nor are the median radial series of spines different from the others. Carinal plates with four or six lobes, and only a little larger than the four-lobed marginal plates. There are three series of four-lobed actinolateral plates, the lowermost plates being much longer than wide owing to a shortening of the transverse processes. Between the carinal and superomarginal plates is a series of mostly three-lobed (sometimes only two-lobed) adradial plates, which are very inconspicuous in all but the largest specimens (where they bear pri- mary spines) owing to encroachment of the adjacent series. These plates extend to the end of the ray but distally are quite small, rather irregular, and pretty completely hidden by the lobes of neighboring plates. The whole skeleton is very open-meshed for a member of this family, and resembles that of a Pedicellaster. (For details of skeleton, see pl. 16, fig. 2a.) There are two series of papular areas between the carinal and superomarginal plates, and four lateral series, each with a large, swollen papula (or rarely two), which does not occupy the whole area. In fully grown specimens each carinal, marginal, actinolateral, and a variable number of adradial plates carries a central stout, tough spine. Those on the carinal, adradial, and marginal plates are conical, usually sharp, and about 2 mm. long in the largest specimen. The spines of the upper actinolateral series are a little longer than the inferomarginal, usually slightly flattened toward the tip, which is broader and blunter than that of the marginal spines. The second row has the longest spines (3 to 4 mm.). These are much flattened and widened, truncate, or lanceolate-sub- acute, often broadly grooved, and incipiently bifid in extreme cases. The lowest ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 53 actinolateral spines are a little shorter, somewhat slenderer, but are often grooved. There is considerable variation in the shape of these actinolateral spines but the essential feature is that they are flattened, broadened, and when fully developed, spatulate. The spines and spinelets are borne on unusually prominent bosses or condyles, which are more prominent than in any member of this family. Each plate carries a number of spaced, slender, often basally curved, sharp, miliary spine- lets 0.5 to 0.75 mm. long. These are rough, sometimes more or less flattened at the tip, and are sheathed in life by a soft, not very thick skin which also covers the plates and bases of the large spines.. Proximally the carinal plates carry 10 or 12 of these spinelets; an adradial plate 3 or 4; a superomarginal plate about 7 or 8; the actino- lateral plates, about 6. Pedicellariae numerous but not especially conspicuous. They are longer than the spinelets but shorter than the spines, have round-tipped, subspatulate jaws, or sometimes slenderer ones, and are variable as to numbers but stand on the edge of the plates so as to be close to the papulae; each papular area has one or two of them as arule. For exact form see Plate 15, Figure 3. Ambulacral furrow wide; tube-feet four ranked the entire length of furrow. Ambulacral pores in four distinct alternating series. Adambulacral plates short separated by muscular spaces about as long as the surface of plates. Prominent plates with a transverse series of four or five, rarely six, slender spines of which the first is well in the furrow and bears a terminal cluster of a few small pedicellariae or one large one. The second and third are usually increasingly longer, reaching a length of 3.5 mm. at base of ray; the fourth and fifth are short spinelets; sometimes the fourth is about half to three-fourths the length of three. On the nonprominent plates of the type are two or three spines. In a large specimen from station 4321 there are four and sometimes five, the outer two or three being spinelets; the second is about the same size as the third spine of prominent plates, while the furrow spine is shorter and often carries a fair-sized pedicellaria. ‘‘In the interradial angles are a very few pedicellariae larger than elsewhere, and these may be 2 mm. long. Oral plates short (as usual in Zoroaster) each with two marginal and two suboral spines, 1 to 2 mm. long; the distal marginal spine carries a cluster of three or four small pedicellariae.”” (Clark.) Madreporic plate subcircular, convex, about 2 mm. in diameter and situated about halfway between center of disk and margin. Color of alcoholic material brown and brownish yellow; small specimens from stations 4432 and 4433 were bleached vermilion when first received; later this color disappeared entirely. In life they were probably bright red (which in the deep sea is equivalent to no color). Anatomical notes—This species has well-developed superambulacral plates. As six fully grown examples of the northern race are available, notes on the soft anatomy will be found below under Myroderma platyacanthum rhomaleum. Young.—The smallest example (station 2960) has R 5.5 mm. and relatively long slenderspines. The adambulacral plates are as yet undifferentiated. A specimen with R 20 mm. has the differentiation of the adambulacral plates well started, but the actinolateral spines are still slender. An example from station 3201 with R 14 mm., when compared with a specimen with R 15 mm. from station 3112, and of the 54 BULLETIN 76, UNITED STATES NATIONAL MUSEUM northern race, is notable for its slenderer rays and relatively smaller disk, char- acteristics of the adults. Both have a complete series of adradial plates. / Specimens with R between 40 and 50 mm. are very numerous, while those with R over 50 are rare. These small examples are sexually mature; in fact, fairly well- developed gonads were found in a specimen only 22 mm. major radius. These smaller specimens differ from the largest chiefly in having relatively shorter rays, an incomplete third actinolateral series of plates, usually few adradial spines (or sometimes none), fewer miliary spinelets (but not always), less extremely flattened actinolateral spines, and two or three spinelets on the nonprominent adam- bulacral plates. The ambulacral pores and feet are in four series and the pedicel- lariae are generally fairly numerous and in size relatively as large as in the big specimens. Type.—Cat. No. 31640, U.S.N.M. Type-locality.—Station 5675, southwest of San Cristobal Bay, west coast of Lower California; 284 fathoms; bottom temperature, 44.6° F. Distribution—From Point Conception, Calif., to San Cristobal Bay, Lower California, in 205 to 287 fathoms, green mud. Specimens examined.—Seven hundred and fifty-one. Specimens of Myxoderma platyacanthum examined pe Locality Depth | Nature of bottom Collection 2909 | Santa Barbara Channel, 34° 22’ N., 120° 08’ 30’ W-- 205 | Green mud_-.....----- % U.S.N.M. 2960 | Santa Barbara Channel, 34° 10’ 45’” N., 120° 16’ 45” W 267s | Sena (oases ae Do. 3200 | Santa Barbara Channel -__--.---.--------------------| 265 |----- Oe eas a ee neste Do. 3201, |-5--= LO ene ee ee eee eee oe | eo ene OnE a ae Ener ee Do. 349977 | (Ott. Sangh lego. Calit-c--- -naseaer. sen aseaneeete enn ae Dark green mud Albatross, 1904 4432 | Off Santa Rosa Island_----- Greentmud 22. -2- -224|-baseees Do. 4433 -|=.--- Oe een nnn eee eee eee | LOO acd eee Ona ae roca s|Seeraas Do 4435 | Off San Miguel Island___-..__....__..-.--..-..--..--| 287-274 |___-. GOS eens ome es Do. aac No locality. eee panne nanan enna nena senna enna nnn enn anne nn] nanan nena nnee nnn nanenee| nena nee U.S. N. M. 2801.| Off Point Coneeptlons=2 22-2 22-322-- 2-2 2e- asec Md oie saeaccceocesce S Do. 1 Adult specimens; all the others are either small or medium-sized examples. 2 Some specimens intermediate with rhomalcum. MYXODERMA PLATYACANTHUM RHOMALEUM Fisher Plate 14, Figures 3, 3a; Plate 15, Figure 2; Plate 16, Figure 1; Plate 23, Figure 1; Plate 24, Figure 2; Plate 25, Figure 3 Myzxoderma platyacanthum rhomaleum Fisner, Ann. and Mag. Nat. Hist., ser. 9, vol. 3 1919, p. 393. % Diagnosis.—Differing from M. platyacanthum in having constantly broader and slightly shorter rays, slightly larger disk, much heavier abactinal and marginal spines slightly shorter and decidedly heavier actinolateral spines, and shorter abactinal med icellariae. R 100 mm.; r 12.5 mm.; R=8r; breadth of ray at base, 13 mm.; at a little beyond base, 15.5 mm. Disk elevated, dome shaped; rays very eradaalls tapered, but not attenuate distally. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 55 Description.—The features which characterize this northern race are more readily appreciated from a comparison of figures. The difference in the width of the ray, for instance, is not great but it is constant even for small specimens and gives the animal a stockier, more robust appearance. In the example of platyacanthum from station 4321 having R 96 mm., a carinal spine at the base of the ray is a trifle over 2 mm. long and 0.5 mm. in diameter at the base. A similar spine in rhomaleum measures about the same length (1.75 to 2.2 mm.) and is 0.65 to 0.75 mm. in diam- eter, and is a bit swollen and thick up to the blunt tip instead of being regularly tapered and sharp. In the southern form the abactinal pedicellariae are 1 to 1.50 mm. in length and very appreciably longer than the miliary spinelets; in the north- ern race they are shorter than or subequal to the spinelets and 0.6 to 0.8 mm. long. The membranous investment of the spinelets is a little thicker than in the southern form but it is rather too slight to be tangible. The specimens from off Pigeon Point, north of Monterey Bay, while less extreme in the racial characters than the specimens from the type locality, belong to the northern form. I think there can be scarcely a doubt that the two races intergrade between Santa Barbara Channel and Monterey Bay. In large well-developed specimens the internal intermarginal ossicles are some- times visible from the exterior. These are oblong ossicles which bind together adja- cent transverse lobes of the supero and infero marginal plates. They are present also for a short distance between the inferomarginals and first actinolateral series. Young.—As noted before, the difference in robustness can be distinguished in smallspecimens. In anexample of the southern form with R 15 mm., ris 2.5 mm., and the breadth of the ray at base, 2.75 mm. Ina specimen of the northern form with R 14 mm., ris 3 mm., or 20 per cent greater, and the breadth of the ray at base is 3.5 mm., or a little over 20 per cent greater, allowing for error in measurement. In the case of specimens of the average size, say with R above 30 mm. and under 50 mm., the differences can be readily seen on comparison of specimens. An example from station 2960 (southern form) has more delicate spines generally than are present on an equal-sized example from 3112. (There are no small examples from Oregon.) The difference in width of ray is slight, but is less in the southern example if R is equal. Anatomical notes.—The stomach fills the disk and is single-chambered, there being short lobes extending into the base of each ray. Through the dorsal surface of these lobes empty two hepatic coeca which extend far along theray. The intestinal coecum is a trilobate, rather irregular sac, about 20 mm. long, proximally narrow, distally expanded. The gonads form a multilobed mass opening on a level with the inferomarginal plates 2 mm. from the interradial line. The prominent knob-like upper end of the first pair of ambulacral plates is con- nected with the interradial angle by a heavy calcareous buttress or bridge which is really the very much enlarged first superambulacral ossicle. (Pl. 14, figs. 3, 3a.) Between the outer ends of these ossicles, which are compressed and rather thick dor- soventrally, there extends centrally the narrow membranous interradial septum, with a long dorsoventral free edge impinging upon the stomach. In the angle formed by the superambulacral buttress (the apex of which is at the interbrachial line) there is a slight depression bisected by the interradial septum, on either side of which there 56 BULLETIN 76, UNITED STATES NATIONAL MUSEUM is an ampulla. Viewed from above, the buttresses plus the enlarged ambulacral knobs form a raised pentagonal frame for the subcircular actinostome. The ambula- cral ridge is permanently bent upward at the base, which causes the actinostome from the outside to appear sunken. Ampullae really single, somewhat triangular in form when inflated; when deflated there appears to be an indication of an incipient external lobe; no Polian vesicles; two Tiedemann organs. The superambulacral ossicles are slender and one to each ambulacral plate; two or three consecutive plates converge to attach themselves to the lower ends of the second series of actinolateral plates. Type.—Cat. No. 37041, U.S.N.M. Type-locality.—Station 2890, off Oregon (43° 46’ N., 124° 57’ W.); 277 fathoms, gray sand; bottom temperature, 42.2° F.; six specimens. Distribution.—Known from off Oregon and central California; 277 to 296 fathoms, gray sand; 41.8° to 42.2° F. Specimens examined.—One hundred sixty-eight, in addition to six from type- locality. Station 3112, off Pigeon Point, north of Monterey Bay, Calif. (37° 08’ N., 122° 47’W.); 296 fathoms, fine gray sand; bottom temperature, 41.8° F.; 179 specimens. Station 3145, off San Luis Obispo County, Calif., 35° 14’ N., 121° 07’ W.; 252 fathoms, green mud; bottom temperature, 43.2° F., nine specimens; bottle broken during earthquake, 1906; locality reasonably certain; specimens not typical, inter- mediate with platyacanthum. Family ASTERITDAE Gray, emended Asteriidae Gray, Ann. Mag. Nat. Hist., vol. 6, 1840, p. 178. A polyphyletic aggregation of genera, some probably very ancient, which have been placed for convenience under the aegis of Asterias. They have the common characteristic of not belonging in the other families of Asteriadina. (See synopsis, p. 4.) SYNOPSIS OF THE SUBFAMILIES OF ASTERIIDAE a, No marked adoral carina, the first pair of postoral adambulacral plates separated interradially (or in contact only along the adoral part of the interradial margin) in combination with inferomarginals having never more than one prominent spine. Rays five or six; skeleton an open network composed of mostly small cruciform or trilobate plates; spinelets small; crossed pedicellariae scattered, never in circlets about spinelets; straight pedicellariae present; no adambulacral spine pedicellariae; tube-feet biserial or quadriserial on proximal partior ray 1222 SS EB SE ES EES Pedicellasterinae Fisher. a’, An adoral carina; i. e., at least one, but usually several, pairs of postoral adambulacral plates in contact by their interradial margins; tube-feet quadriserial at least proximally. b!. Adambulacral spines without attached pedicellariae, singly or in clusters, although these may occur on the oral spines. c!, Primary apical plates conspicuously enlarged; abactinal and marginal plates subhexagonal, closely imbricated in seven regular longiseries (resembling Zoroaster), sparsely granu- lated; actinal plates with short spinelets_________________ Neomorphasterinae Fisher. c. Primary apical plates not conspicuously enlarged; rays not resembling those of Zoroaster. d', Rays numerous, long, slender, in combination with only one inferomarginal spine (on each plate) carrying a prominent wreath of crossed pedicellariae. No actinal plates; abactinal skeleton either very open with large squarish meshes or else abortive with scattered independent plates; crossed pedicellariae in abactinal spinal IWIEALOS ORAUNICK TUN Sea. ate ee oe Ss a Labidiasterinae Verrill. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 57 d. Rays five to many; in combination with two inferomarginal spines, heavily sheathed, and an abortive abactinal skeleton and no actinal plates; abactinal spines bearing prominent wreaths of crossed pedicellariae__-_-------------- Pycnopodiinae Verrill. d@. Rays five to many; with a well-developed abactinal skeleton, two sheathed inferomar- ginal spines and one series of actinal plates. Carinals, marginals, actinals and often dorsolaterals in definite longiseries; abactinal, marginal, and actinal spines (when present) prominent, spaced, styliform or acicular, normally one to a plate except inferomarginals), wreathed with pedicellariae and often in evident longi- pericd eeteen oe. tclaeus ta! = site Se Se teu ss 5-58 2-2- Se Coscinasteriinae Fisher. d‘. Rays five, in connection with peculiar macrocephalous crossed pedicellariae and abactinal spines lacking (or with only rudimentary) wreaths of pedicellariae; carinal and marginal plates prominent with prominent spine (inferomarginals in one case with two); actinal plates wanting or in one series. Arctic and Antarctic. Notasteriinae Fisher. b2 Adambulacral spines carry pedicellariae singly or in clusters, or are entirely without attached pedicellariae; abactinal spines not as a rule prominent, styliform, or acicular and more or less spaced and isolated, but short, slender to stout, conical, tubercular-subglobose, variously granuliform, sharp to capitate, single or in groups; abactinal plates in more or less definite longiseries or irregularly reticulate, sometimes abortive; actinal area sometimes broad, with upwards of five longiseries of plates, sometimes without any actinal plates; gonads opening dorsally, laterally, or ventrally -----~--------------------=--2- eon n nnn Asteriinae. Subfamily PEDICELLASTERINAE Fisher Pedicellasterinae Fisuur, Ann. Mag. Nat. Hist., ser 9, vol. 2, 1918, p. 108; vol. 12, 1923, p. 249. Asteriidae without an adoral carina (the first pair of postoral adambulacral plates separated interradially by a muscular symphysis or in contact only along the adoral part of interradial margin); skeleton an open network composed mostly of small cruciform or trilobate plates, the dorsolaterals in irregular, the carinal and marginal plates in regular longiseries; abactinal spinelets small, generally one to a plate; never more than one prominent inferomarginal spine; crossed pedicellariae scattered, never in circlets about spinelets; straight pedicellariae present; no adambulacral spine pedicellariae; rays five or six. KEY TO THE KNOWN GENERA OF PEDICELLASTERINAE a. Inferomarginal spines not conspicuously larger than the superomarginals, nor forming a promi- nent longiseries external to the adambulacral spines; the latter are the longest on ray, in transverse combs of two to five; no quartet of enlarged or especially strong plates in each interbrachium; tube-feet biserial; first postoral pair of adambulacral plates widely separated interradially. b!, Actinal plates present. Crossed pedicellariae with one or more enlarged teeth on the distal portion of the jaw. cl. Straight pedicellariae not unusually large, nor spatulate-unguiculate; gonads opening ven- trally; actinal plates of large specimens in closely imbricated transverse series, the number of plates per series (in some species) increasing on middle third of ray instead of decreasing; crossed pedicellariae of two sorts, the larger with slenderer jaws and four large claw-like terminal teeth and one to four conspicuous teeth on the shank, below the terminal; the smaller (abactinal) pedicellariae have numerous small terminal teeth, none conspicuously enlaxeec eee tls IEEE Fee Bae oben naa ee Pedicellaster Sars. c?, With very large spatulate-unguiculate straight pedicellariae; gonads opening dorsally; actinal plates in two simple longiseries; crossed pedicellariae, not obviously of two dif- ferent sorts, have one or two enlarged lateral terminal teeth and numerous small ones. Peranaster Fisher. 58 BULLETIN 76, UNITED STATES NATIONAL MUSEUM b?, Actinal plates present; crossed pedicellariae with the numerous terminal teeth uniformly tiny; gonads opening ventrally; actinal plates in one or two longiseries; prominent unguiculate straight pedicellariae in some species__-__--~--_--------- Anteliaster Fisher. bs. Actinal plates absent, the inferomarginals juxtaposed to the adambulacrals; inferomarginal spinelets small; crossed pedicellariae all of one kind, small, with numerous small uniform terminal teeth; gonads opening on extreme edge of abactinal area___Hydrasterias Sladen. a?. External to the adambulacral spines is a longitudinal series of prominent inferomarginal spines conspicuously larger than the superomarginals (which are subequal to the abactinal spine- lets); no actinal plates; a quartet of strong interbrachial marginal plates; first pair of postoral adambulacral plates narrowly separated or touching by the adoral corners. b!. Straight pedicellariae not unguiculate nor broadly spatulate; an accessory inferomarginal spinelet above the major spine (at least proximally); adambulacral plates diplacanthid or diplacanthid and monacanthid; interbrachial marginals not much enlarged; supero- marginals regularly four-lobed (not warped or irregular, nor three-lobed) __ Tarsaster Sladen. b?. Straight pedicellariae unguiculate, often also strongly spatulate; no accessory inferomarginal spinelet or tubercle; adambulacral plates predominantly monacanthid (a few plates may be diplacanthid); two enlarged interbrachial superomarginals overlap two corresponding, sometimes enlarged inferomarginals; superomarginals often three-lobed or irregularly four- lobed (proximal plates generally fairly regular) -_-_+..------------- Ampheraster Fisher. Genus PEDICELLASTER Sars Pedicellaster Sars, Oversigt af Norges Echinodermer, Christinania, 1861, p. 77. Type P. typicus Sars.—FisHxEr, 1923, p. 251. Diagnosis.—Crossed pedicellariae of two kinds: larger, with slender jaws having usually four curved prominent terminal teeth, and below these on the slender shank, one to five slender thornlike teeth; the smaller pedicellariae of the usual Asteriid type; actinal plates well developed, in transverse series, the number of plates in series in the adults of some species increasing toward the middle third of ray and decreasing in the distal third; young specimens with one or two longitudinal series; skeleton of the quadrate-mesh type, often delicate, of 4+-and Y-form plates, the intervals medium sized to large; dorsolateral skeleton irregular; spinelets small, the inferomarginal not conspicuously larger than the rest; the first postoral pair of adambulacral plates widely separated interradially; furrow narrow, tube-feet biserial; gonads normally opening laterally at a slight distance from disk. Remarks.—The characteristic structure of the actinal skeleton is not attained until specimens have reached some size. It is, however, fundamentally different from that in large examples of Anteliaster, where the actinal plates are in one or two simple longiseries, the outer extending farther long the ray than the inner. Young Pedicel- laster passes through this stage, and, so far as the actinal plates are concerned, is then not different from Anteliaster. Later, in magister, megalabis, and orientalis, additional plates are added more numerously in the middle third of the ray than at either the base or distal portion, and the arrangement in longiseries is consequently lost. The plates become closely imbricated in transverse series, and the transverse series tend to become less well connected with their neighbors. Young examples of Pedicellaster may be recognized by the presence of two sorts of crossed pedicellariae, of which the larger, ventral, sort have slenderer jaws with only four terminal teeth. None of the other nearly related genera have this type of pedicellaria, the terminal teeth in all cases being uniformly small and the jaws rela- tively shorter and stouter. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 59 Koehler, 1920 (p. 109), gives a list of the nominal forms of Pedicellaster: antarcticus Ludwig. parvulus Perrier. atratus Alcock. pourtalesii Perrier. formatus Koehler. reticulatus H. L. Clark. hypernotius Sladen. sarsi Studer. hyperoncus Clark (Ampheraster). scaber Smith. improvisus Ludwig (Hydrasterias). sexradiatus Perrier (Hydrasterias). octoradiatus Studer. typicus Sars. palaeocrystallus Duncan and Sladen. Of these antarcticus, formatus, possibly hypernotius, pourtalesii, and typicus (includ- ing palaeocrystallus) are true Pedicellaster. I have examined specimens of P. pour- talesti, loaned by Dr. H. L. Clark. They are too small to show the characteristic actinal structure, but the larger pedicellariae are of the characteristic fanged type. Atratus is possibly a true Pedicellaster. Alcock mentions large pedicellariae which is a characteristic of Pedicellaster as contrasted with Anteliaster or Hydrasterias. He also says that there are 14 longitudinal rows of plates (probably either 13 or 15) which seems to indicate about three series of actinals. P. octoradiatus Studer is probably not a Pedicellaster. P. parvulus is a young Sclerasterias, judging by one of Perrier’s specimens which I have examined. : PEDICELLASTER MAGISTER Fisher Plate 16, Figure 3; Plate 26, Figures 2, 2a-2f; Plate 27, Figures 2, 2a—2d; 6, 6a, 6b; Plate 28, Figures 1, 1a-1b; Plate 33; Plate 34, Figure 1; Plate 36, Figure 2 Pedicellaster magister Fisner, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 251. Diagnosis.—Differing from typicus in regularly attaining a relatively gigantic size, with extensive dorsolateral region and a conspicuous actinal area crossed by transverse series of imbricating, four-lobed plates which increase in number for each series toward the middle third of the ray, and decrease slowly in the final third; in having differently formed, slenderer-jawed, major crossed pedicellariae, as well as differently shaped minor ones. Type, R 85 mm.; r 12 mm.; R=7 r; breadth of tay at base, 13 mm. Paratype, station 4792, R 70 mm.; r 11 mm.; R=64 r, Breadth of ray at base, 14mm. Rays slender, flexible, slightly inflated above base, very gradually tapered to a bluntly pointed extremity. Description —The following description applies particularly to the full-grown large specimens from stations 3223, 3224, 3257, 3258, 3675, 4786, 4791, 4792: In alcoholic specimens the rays are flexible and the body wall rather thin. The arrange- ment of the plates is not at all visible, since the entire surface is thickly covered with small uniform spinelets 0.5 to 0.6 mm. long, their true size augmented somewhat by a pulpy sheath. Between the spinelets are numerous pedicellariae, shorter than the spinelets, appearing as smaller pulpy papillae, while interspersed among these are the papulae—numerous in the aggregate, but only a few to each area. No spinelets are conspicuous by superior size until the double row along the furrow margin is reached. Along the sides and actinal surface of the ray the larger of the two sorts of pedicellariae are very numerous, so closely placed as to touch one another by the investing sheaths. 60 BULLETIN 76, UNITED STATES NATIONAL MUSEUM In prepared specimens: The carinal marginal and actinal plates are regularly four- lobed. The carinals are distinguishable from the dorsolaterals mainly by reason of regularity, the latter (as seen in the figures) being irregularly arranged and not symmetrical in form. New plates are continually being added to the dorsolat- erals. In very small specimens there is a single row. I have none small enough to demonstrate their absence. A specimen of true typicus with R only 8 mm. has a single series of three-lobed dorsolaterals. In big specimens the marginal plates are lateral and bend upward a little at the interbrachium. The superomarginals form a sharp line of demarcation between the irregular dorsolaterals and the regular trans- verse ranks of actinals-plus-marginals which are characteristic of very large specimens ofthis genus. The plates strongly overlap as shown in Plate 28, Figures 1, la, and 16. There are 4 or 5 actinals in each transverse series at the base of the ray, increasing to 8 to 11 at about the middle, and then decreasing again near the tip. The actinal plates do not, therefore, stand in regular longitudinal series on account of this highly peculiar arrangement. The actinals are rather thin around the edges. In a great mass of small plates it is sometimes difficult to be sure of the marginal series, and it is essential to be certain. The superomarginals, in addition to standing at the upper end of the transverse rows, have both their transversely oriented lobes overlapping those of their neighbors. The plates usually bear a single spinelet only, except the carinals and the larger dorsolaterals, which commonly carry two or three. Over the disk the spinelets are rather thickly placed, most of the larger plates having two or three, and I find some specimens in which the proximal superomarginals haye one or two smaller accessory spinelets. The spinelets, averaging 0.45 to 0.6 mm. long, end in three to several sharp divergent points, except the smaller secondaries which may have but 1. (Pl. 27, figs. 6, 6a, 60.) : The adambulacral spines, two to a plate in an oblique transverse row, form two regular series on the edge of the furrow. The inner spine is slender, slightly tapered and pointed; theouterisa little stouter and longer, sometimes slightly tapered and pointed, sometimes somewhat clavate and blunt. Occasionally there are three spines to a plate either in a regular transverse series, or two are rather obviously smaller, furrow, spines and the third a heavier subambulacral. The first pair of adambulacral plates do not meet in the interradial line back of the mouth plates. A very few small blunt ovate straight pedicellariae (0.25 to 0.27 mm. long and about 0.18 broad) occur here and there along the inside of the furrow. The mouth plates, the form and armature of which are best appreciated from the figure, usually have a longitudinal series of four fairly long spines and at the inner end of the plate, one, two, or three smaller actinostomial teeth, with, occasionally, a tiny ovate straight pedicellaria, 0.25 mm. long. The papulae, usually one to an area, are small and in alcoholic specimens rather hard to distinguish. The crossed pedicellariae are of two sorts and are of definite diagnostic value. The larger kind (pl. 26. figs. 2, 2a-2e) are very abundant on the actinal and lateral surfaces, and sometimes in big examples (station 4792) on the dorsolateral regions also. Tn small specimens they are restricted to the lateral and actinal regions, the latter, of course, very narrow. The smaller sort are found on the abactinal surface very ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 61 plentifully on the marginal plates, and sparingly on the actinal area. The larger kind have slenderer jaws with two pairs of prominent terminal teeth and on the inside of each jaw two, less often three, slender sharp thorns. The largest measured, from a huge specimen, was 0.6 mm. long, but this is exceptional; 0.45 to 0.55 mm. is the average largest on big specimens. Small examples have the same sort, only smaller—about 0.28 to 0.3 mm. in an example with R 12 mm. (See pl. 27, fig. 2b, magnified 200 times, twice that of the figures 2, 2a. Pl. 26, figs. 1, la, 1b, lc, are from very small typicus, enlarged x200; 1c is abactinal.) The smaller pedicellariae (pl. 26, fig. 2f) are much shorter and relatively broader, with a broad, many-toothed terminal portion, similar to that of the usual type of small crossed pedicellaria. Both kinds differ from the corresponding ones of true typicus (of which a specimen, - probably from Norway, was loaned by Dr. H. L. Clark). Compare Plate 26, Figures 1-16, showing the larger pedicellariae of typicus magnified 200 times, with Plate 27, Figure 26, showing those of a small specimen of magister from station 4792, same enlargement. Figures 2 and 2a are enlarged only 100 times. The jaws of the pedi- cellariae from typicus are much heavier and have four to six median teeth. The smaller sort (pl. 26, fig. 1c), distinguishable by the many toothed terminal margin, is also different, having more numerous teeth on the cutting edge of the jaw, as well as a somewhat different form. The straight pedicellariae are absent in some specimens; in others a very few tiny ovate ones, sometimes blunter than the figure, occur sporadically along the margin of furrow and at the base of the innermost oral spine—in the last position, always singly. (Length, 0.25 to 0.27 mm.) Madreporic body inconspicuous, often irregular, one-third to one-fourth distance from margin to center. Young specimens.—These have slender rays and the skeleton is characterized by a restriction of the dorsolateral plates to one or two series, while the actinals are in one or two longitudinal series (one series in a specimen with R12 mm.). It is curious that these very small specimens do not show the arrangement in transverse series which is so characteristic of mature individuals. A specimen from station 4243 with R 28 mm. does not exhibit any multiplication of the distal actinal plates (one longiseries beyond middle of ray). However, another from station 4792, with R 30 mm., has four or five actinal plates in each transverse series and is constructed like one of the very large examples. One of the generic characters, therefore, is not found in very small specimens and may not appear until R is about 30 mm. In lieu of the actinal plates, the terminal claws of the crossed pedicellariae will suffice to distinguish young Pedicellaster from young Anteliaster. It is noticeable that the plates of the young have stout lobes like those of the adult. The immature stage can be readily separated from those of megalabis on plate as well as pedicellarian characters. The spinelets are relatively slenderer than in the big specimens with R 60 to 85 mm.; there is usually one to a plate, and the pedicellariae are less crowded. Anatomical notes—The gonads form each a bushy tuft of branched tubules and open 3 to 5 mm. from the interbrachial angle (R 70 mm.), on the side of the ray in a variable relation to the plates—sometimes between the inferomarginal and actinal plates, and in one case just above the superomarginal series. 64406—28——5 . 62 BULLETIN 76, UNITED STATES NATIONAL MUSEUM The stomach is very spacious, filling the entire disk and reaching into the base of the rays. It has a single chamber, the hepatic coeca entering the dorsal part of each lobe. The intestinal coecum consists of two short thick lobes. The food is evidently ingested entire, as the stomach was full of small gasteropods. The ampullae are rather large, strictly simple, not bilobed, and the tube-feet are biserial. The radial nerve fold and circumoral pentagon are rather thick. Type.—Cat. No. E, 1418, U.S.N.M. Type-locality—Station 4792, off Cape Monati, Bering Island; 72 fathoms, pebbles. Distribution.—Southern Bering Sea, from the Commander Islands to Unimak, and north to 57°; south along the Alaskan coast to Kasaan Bay, Prince of Wales Island; 42 to 121 fathoms, on gravel, black and gray sand and green mud. Tem- - perature range typically 37.3° to 39.8° (an exception station 4292). Specimens examined.—Thirty-eight. Specimens of Pedicellaster magister examined Bottom! Num- aed Locality Depth Nature of bottom _|temper-| ber of Collection ature pee men 3223 | Between Unalaska and Unimak_-__--_---------------- 56 | Black pebbles___------ 39 4| U.S. Nat. Mus. 3224 |..--- 0S ee nee ee aede ce receen ena eee nceneena sae 121 | Black sand; gravel_---- 38.7 1 Do. 3257 | North of Unimak Island ---------------------------- 81 | Gray sand; gravel-..-- 39 1 Do. 3258 |----- 0 Se ee ae ee ne nes ee ae oa anemones 70 | Black sand; gravel -.-| 39 1 Do. 3488 | Bering Sea, 57° 05’ N., 173° 47’ W___----------------- 106 | Green mud; graysand_| 37.3 1 Do. 3500 | Bering Sea, 56° 02’ N., 169° 30’ W---- oe 121 | Fine gray sand; gravel-| 38.6 4 Do. 3675 | Off Karluk, Kadiak_...........---------- aoe 110 | Green mud_----------- 39 2 Do. 4243 | Kasaan Bay, Prince of Wales Island, 22s] (42-47)|esaoe Cs (pl ere i 49.1 1 | Albatross, 1903. 4292 | Shelikof Strait, Alaska. -...-2_-..-------------------- 102-94 | Mud; fine sand__----- 39.8 1 Do. 4786 | Off Medni, Commander Islands--------------------- b4)| Greenisand — == 2.22 -|2ee--—s 1 | Albatross, 1906. 4791 | Off Cape Monati, Bering Island---.------.---------- MOT ROCKY eee saseeananees |semeaene 3 Do. 4792 |____- (i (ps Sees eee «a ne eee Wan) Rebblesses-te ete samen | aca 18 Do. Remarks.—Pedicellaster typicus, from the northern part of the North Atlantic and adjacent Arctic Ocean seems to be rather further removed from magister than are either of the Pacific subspecies. It is a small form, the largest specimen recorded by Danielssen and Koren ” being but 42 mm. in diameter, while most of their specimens ranged from 10 to 23 mm. in diameter. The type of magister is 170 mm., and many are over 100 mm. in diameter. According to Danielssen and Koren, true typicus is an Arctic form which extends southward on the European coast to Sognefjord, Norway. It is found on the Murman coast; at Nova Zembla, Spitzbergen, Jan Mayen; in Barents Sea; Kara Sea; on the west side of the Taimur Peninsula (the northeast border of the known range). On the American side it has been taken as far south as 42° (Verrill, 1895), and north through Davis Strait as far as Discovery Bay in Grinnell Land, 81° 41’ north latitude (Duncan and Sladen). Verrill, 1914 (p. 203), has recorded a small example from Icy Cape, Alaska, well within the Arctic Ocean. This specimen (No. 6123, U.S.N.M., 10 to 15 fathoms, mud and sand, W. H. Dall, 1874) can not now be found. If it is true typicus (and not a young specimen of magister), the range is therefore cireumpolar, and intergradation 7 Asteroidea (Norwegian North Atlantic Expedition, 1876-1878), 1884, p. 38. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 63 with magister, if it occurs at all, must take place between Icy Cape and southern Bering Sea. After examination of the type of typicus, Danielssen and Koren call attention to the fact (1884, p. 37) that the original figures and description of the pedicellariae given by Sars are not quite correct. They state that in the type the pedicellariae are exactly like the figure given by Duncan and Sladen (1881, pl. 2, fig. 26). I have carefully examined pedicellariae of a specimen of typicus, believed to have come from Norway, and find more numerous teeth on the shaft. The pedicellaria figured by Duncan and Sladen is not in all probability a typical ventral one, as the terminal teeth appear to be more like those of the dorsal pedicellariae, or of an inter- grade between the two sorts. Although magister has much the same appearance as typicus the characters offered by the very numerous major crossed pedicellariae are diagnostic, while the extraordinary development of the actinal plates, in transverse series, is not found in typicus, although undoubtedly latent there. As mentioned below, typicus may not be even closely related to magister. The specimen from station 4243, Kasaan Bay, Prince of Wales Island, Alaska, belongs quite evidently to the Alaskan rather than to the southern race of the species. The major crossed pedicellariae are smaller than in megalabis, especially contrasting with the Washington example of the latter, which, however, is not precisely typical. The minor pedicellariae have the fewer proximal shank teeth of the northern form. Some light is thrown upon the relationship of magister and typicus by two Ant- arctic species, P. antarcticus Ludwig and P. formatus Koehler, both of which appear to be more closely related to magister than is typicus. P. formatus Koehler (1920, p. 106, pl. 16, figs. 1, 9, 10; pl. 17, figs. 6, 7; pl. 58, fig. 4) from latitude 66° 8’ S., longitude 94° 17’ E., 120 fathoms, has a robust skeleton and there are proximally four plates in each transverse actinal series; three further along the ray. R varies from 38 to 40 mm. The plates are stouter even than in P. magister, but the major crossed pedicellariae are closely similar in form although they are somewhat larger in size (averaging 0.6 mm.) There are one or two teeth below the terminal set of four. Koehler describes the straight pedicellariae (pl. 58, fig. 4b) as occuring in the ambulacral furrow. They are very rare in magister; occasionally a small one, very similar to those of formatus, is found on the oral plates, less often at wide intervals in the furrow. In fact they may be described as absent from the furrow, since their presence there is so rare as to have little significance. P. antarcticus Ludwig (1903, p. 35, pl. 4, figs. 32-38) from between 70° and 73° south, and $2° and 87° west, 450 meters, has a skeleton which is much more delicate and is analogous to that of megalabis. The major crossed pedicellariae are smaller however (0.35 to 0.43 mm. high) and in form a little stouter than those of megalabis especially as regards the three or four median teeth. The size of the pedicellariae is nearer that of the major crossed pedicellariae of orientalis. The straight pedicellariae of antarcticus are 0.16 to 0.22 mm. long, those of megalabis more than twice that and of a different form. The presence in the Antarctic seas of two species so similar to three North Pacific forms is of great interest, and is a bit of evidence in favor of the Antarctic origin of the cold water of intermediate depths of the North Pacific. In time we shall 64 BULLETIN 76, UNITED STATES NATIONAL MUSEUM doubtless find a chain of closely related forms connecting antarcticus with megalabis, just as we are pretty certain that there is a continuous distribution of Pedicellasters from southern California to Japan. Clark '8 has stated the case for Florometra, where the greater number of species furnishes more striking evidence. I think it not unlikely that P. typicus is derived from a distinct line of forms via the South Atlantic and is not at all a small offshoot of magister as might at first sight seem probable. The major crossed pedicellariae, although keeping the characteristic generic form, are rather more different from those of magister than are the homologous pedicellariae of formatus. Pedicellaster pourtalesii Perrier is one of the forms of the Atlantic cycle. The stomach of a specimen from station 4786 was full of gastropods, the largest 7 mm. in diameter. PEDICELLASTER MAGISTER MEGALABIS, new subspecies Plate 16, Figure 4; Plate 26, Figures 3, 3a-3e; Plate 27, Figures 4, 4a; Plate 28, Figure 2; Plate 4, Figures 2, 3 Diagnosis.—Diftering from Pedicellaster magister in smaller size, decidedly more delicate plates, and more open skeleton; in the larger size of the crossed pedicellariae and in the presence of numerous much larger adambulacral straight pedicellariae proximally, as well as in the greater distance of the gonads from interbrachial angle. Type: R 43 mm., r6 mm., R=7+r; breadth of ray at base, 6.5 mm. Rays slightly swollen above base, slender, gradually tapered to a bluntly pointed extremity; body wall weak; plates and spines invested by a thin membrane. Description.—None of the specimens of this race are so large as the maximum of magister. The largest example from station 3347 has R 48 mm. and another from 4427 has R 40 mm. Alcoholic specimens can generally be recognized by the much larger meshes of the skeleton and the thinner membranes covering the plates, while if two equal sized specimens are placed side by side the actinal major pedicellariae of the southern form are seen to be much larger. The skeleton is arranged as in the northern race but is much more delicate, as can be best seen from the figures. The difference is as well marked in young as in adults and is probably correlated with the greater depth of the habitat. The skeleton may be described as open and more loosely joined than in magister. The actinal plates form similar transverse series, a maximum of six plates occurring in the largest specimens. The plates bear a single, generally three-pronged spinelet, about 0.5 mm, long, and averaging a little slenderer than those of magister, as would be expected from the more delicate skeleton. There are two very slender, tapered, sharp adambulacral spines in an oblique transverse row, the furrow spine a little aboral to the other and a trifle shorter and slenderer. On the furrow face of the proximal plates is a broadly lanceolate, small pointed straight pedicellaria (0.45 to 0.48 mm. long). The oral plates generally carry a row of three sometimes four slender spines, and on the surface of the plates one to three straight pedicellariae like those of the adambulacrals. Papulae are one, occasionally two, to each skeletal mesh. The crossed pedicellariae are of two kinds, both of which are very similar to those of the northern race yet differ in respect to size and details. The minor pedicellariae ik 18 A. H. Clark. The Circulation of the Abyssal Waters of the Oceans, as indicated by the Geographical and Bathymetrical Distribution of Recent Orinoids. Bull. inst. oc6anographique, No. 285, February, 1914. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 65 are distinctly larger even in specimens half the size of the big examples of magister, and have five or six median teeth in the vertical row in place of the usual four of magister. 'These pedicellariae are about 0.3 to 0.35 mm.long. The larger sort are also distinctly bigger, ranging in length of jaw, in the largest specimens, from 0.55 to 0.65 mm., the latter from the largest specimen, R 50 mm. (station 3347). Comparable specimens of magister have the larger pedicellariae 0.37 0.45 If two approximately equal-sized specimens are placed side by side the conspicuously larger pedicellariae of the southern form can easily be seen with an ordinary glass. Specimens from the southern extremity of the known range frequently have three or four unpaired median teeth as against two or three in the Washington specimen, and two in most examples of magister (but sometimes three). The madreporic body is small and near the margin. Anatomical notes.—The gonads, similar in form to those of magister, have slender branched lobes, and form a tuft which opens just under the inferomarginals at a con- spicuous distance from the interbrachium—about 1.5 r, or about one-fifth of R. This is much farther out relatively than the opening in magister. Young.—The young exhibit the same differences from the adult as characterize magister, namely, the reduction of the actinal and dorsolateral regions. The plates are consistently more delicate than in the young of magister (compare pl. 28, fig. 16 with pl. 28, fig. 2a); while the pedicellariae are larger. Type.—Cat. No. E. 1419, U.S.N.M. Type-locality Station 4335, off San Diego, Calif., 14 miles southwest Point Loma Light, 500 to 530 fathoms, green mud, fine sand; bottom temperature, 39.5° F. Distribution —From the vicinity of San Diego, Calif., to Washington (45° N. lat.) in 284 to 530 fathoms, green and yellow mud or black sand. Temperature range, 39.5° to 44.1° F. Specimens ecamined.—T wenty-three. Specimens of Pedicellaster magister megalabis examined Bottom) Num- rie Locality Depth Nature of bottom — Pe Collection ature | mens 2892 | Off southern California, 34° 15’ N., 120° 36’ W_____-- 284 | Yellow mud_--_-._____- 44.1 8 | U.S.N.M 2925 | Off southern California, 32° 32’ 30’ N., 117° 24’ W__- SHOU dee cece ped eee 42.9 1 Do. 2928 | Off southern California, 32° 47’ 30’’ N., 118° 10’ W___ 417 | Black sand, gravel --__ 41 3 Do. 3347 | Off Washington, 45° 09’ 35’’ N., 124° 45’ W_________- 845), Mudsaiti ure. esate 40.9 2 Do, BSG8) OM SANE DIORO. ASAI sce. en ee cat et ee om | 301-487 | Green mud___----.....| | 41.7 4 | Albatross, 1904. 4334 |___-- OO ean eee ee a seen eae ng conn ane | 525-541 | Green mud, finesand_| 40 | 1 Do. 4338 |ou0.. GOL. eee PETS tort he Or L | 500-530 |__.__ Go TREY 39.5 | 3 Do. 1 4351 |_.--- Oe eee RO ed oes ee ee eee | 423-488 | Soft green mud-__--..-.|...----- Do. Remarks.—There are no specimens available between station 42438, the southern- most record of magister, and station 3347, off Washington, the northernmost for megalabis. Intergradation therefore has not been proved, but the southern form seems to be quite evidently a deep-water representative of magister. It is noteworthy that while the major crossed pedicellariae of megalabis are larger than those of magister, the reverse is true of the race from the sea of Japan. 66 BULLETIN 76, UNITED STATES NATIONAL MUSEUM A specimen from station 4427 and another from station 4334 contain each a good sized parasitic Dendrogaster, probably D. arbusculus * as the general external form is the same as in the type of that species. PEDICELLASTER MAGISTER ORIENTALIS, new subspecie o Plate 16, Figure 5; Plate 27, Figures 1, la—-1c, 5; Plate 28, Figure 3; Plate 34, Figure 5 Diagnosis —Similar in general appearance to Pedicellaster magister but differ- ing in the following respects: Major crossed pedicellariae slightly smaller, with four or five teeth in the median vertical series, instead of two; small ovoid straight pedi- cellariae numerous on mouth plates; actinal plates fewer in each transverse series. Rays slender, subterete, slightly swollen proximally, very gradually tapered to a blunt point; disk small. R 52 mm., r7 mm., R=7.4+1; breadth of ray at base, 7 or 8 mm. Description—In alcoholic specimens: The surface is covered by small, spaced, uniform, pulpy papillae—the spinelets—which are very inconspicuous, being 0.5 to 0.7 mm. long, interspersed with numerous sheathed pedicellariae that increase in number and size on the sides and actinal surface. The papulae are small and not easily distinguished. The surface of the rays has a soft, almost downy, appearance owing to the small size of the spinelets and pedicellariae, and is much the same as in alcoholic examples of magister. The furrow is bordered by a double row of pulpy spinelets. The arrangement of the plates is essentially like that of magister, the dorsolaterals and carinals being, if anything, a trifle broader lobed, but this feature is undoubtedly variable. In a specimen with R 49 mm. there is a maximum of three actinal plates to a transverse series in the median third of the ray. An equal-sized specimen of megalabis has five or six plates to a series, and one of magister from station 4791 as many as 10. It is perhaps a matter of age, rather than size, and I do not know whether the smaller number in orientalis is constant. I think it probably is, as the ray is more attenuate than in magister. In a dried specimen the abactinal spinelets, which are tipped by three to several rather divergent hyaline points, reveal themselves in lines or groups of two, three, four, and rarely five to a plate, the latter number occurring on the carinals. In the type, however, the plates carry generally only one or two. The superomarginals have one spine with sometimes one or rarely two smaller accessory spinelets, and the actinals carry a single small spinelet. Adambulacral spines, two to a plate, similar to those of magister. The mouth plates carry four or five slender spines, in a longitudinal, curved series, increasing slightly in length from the inner to the outer. When there are five spines the two outer form a transverse series. The mouth plates carry rather numerous, small, straight pedicellariae, oval, blunt, and much smaller than in megalabis. (Compare pl. 16, figs. 4 and 5.) The major crossed pedicellariae occur on the marginal and actinal plates very abundantly; the smaller sort, on the abactinal and superomarginal plates, but not on the actinal plates. The major variety are smaller on the average than in magister, 9 Fisher, Bull. 76, U. S. Nat. Mus., 1911, p. 404, pl. 3, fig. 1. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 67 the largest being 0.34 to 0.39 mm. long. But the main difference is in the struc- ture and in the presence of more numerous teeth (four or five, less often six) in the vertical series of each jaw. Compare figures. The presence of numerous small oral straight pedicellariae (pl. 16, fig. 5) is a feature not found in magister, except sporadically in rather small specimens (station 3500) when only one or two are present. Madreporic body very small, situated variably in the outer half of r. The gonads, similar to those of magister, open just under the inferomarginals a little less than the length of r from the interbrachium. Type.—Cat. No. E. 1420, U.S.N.M. Type-locality.—Station 4867, off east coast of Korea, 36° 31’ N., 129° 46’ E.; 150 fathoms, green mud, fine gray sand; bottom temperature 33.4 F.; five specimens. Distribution.—This race is probably found throughout the cold western part of the Sea of Japan. Remarks.—This form is well marked on account of pedicellarian characters alone. The slighter development of the actinal areas may prove to be a fundamental difference. The skeleton, if anything, is closer knit than in magister. The lobes of the abactinal plates are broader and the spinelets have rather more numerous termi- nal points. Genus PERANASTER Fisher Peranaster Fisoer, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 252. Type Pedi- cellaster chirophorus Fisher (Celebes). Diagnosis.—Pedicellasterinae resembling Pedicellaster but differing in having spatulate unguiculate straight pedicellariae; only one sort of crossed pedicellariae; the gonads opening dorsally, and the actinal plates in normal longiseries (not reaching and of ray). Carinals, marginals, and actinals 4 form, monacanthid, in regular longi- series; dorsolaterals Y form in a zigzag longiseries; papular areas in two dorsolateral, one intermarginal, and two actinal series for each side; adambulacrals triplacanthid and diplacanthid (the spinelets longer than the marginals); oral plates relatively large with a longitudinal series of four or five spinelets; postoral pair of adambulacral plates separated interradially; tube-feet biserial; gonads opening dorsally. Remarks.—This group resembles Anteliaster in having the actinal plates arranged in longiseries, and in the form of the straight pedicellariae; but differs in having the gonads opening dorsally at the margin of the abactinal area, and in the different form of the crossed pedicellariae. These have an enlarged tooth on one side of the expanded terminal portion of the jaw. They resemble some of the pedicellariae intermediate between the two types characteristic of Pedicellaster, s. s. Hydrasterias has no actinal plates on the ray and the crossed pedicellariae are more nearly like those of Anteliaster. The genus is known only from the type, taken at station 5656, Gulf of Boni, Celebes, 484 fathoms. 68 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Genus HYDRASTERIAS Sladen Plate 27, Figures 7, 8 Hydrasterias SuapEN (subgenus), Challenger Asteroidea, 1889, p. 581. Type Asterias (Hydrasterias) ophidion Sladen—FisHEr, 1928, p. 251. Pedicellaster part Perrier, Exp. Sci. Travailleur et Talisman, 1894, p. 100—Lupwiae, Mem. Mus. Comp. Zodl., vol. 32, 1905, p. 216. Diagnosis.—Typical Pedicellasterinae differing from Pedicellaster in the entire absence of actinal plates and in having only one kind of crossed pedicellariae. Infero- marginal plates juxtaposed to adambulacral plates; inferomarginal spinelet not conspicuously larger than the superomarginal and abactinal spinelets which are small, slender, sharp, and isolated; carinal and superomarginal plates —- form; infero- marginals same, but with ventral lobe more or less suppressed; dorsolateral skeleton somewhat irregular, as a rule, with two or three longiseries of large meshes, the plates either three or four lobed, and in well-grown specimens connected by slender, elliptical oblong secondary ossicles; first pair of postoral adambulacral plates entirely separated interradially; adambulacral spines two or three in a transverse series; crossed pedi- cellariae rather thickly scattered over papular areas and on plates but not on spines, all of one kind, without enlarged terminal teeth as in Pedicellaster; straight pedicel- lariae small and confined to adambulacral and mouth plates; or larger, blunt, spatulate denticulate ones may be present in axillary region; gonads” open on side of ray just above the superomarginals and hence on lower edge of the abactinal region. Remarks.—Hydrasterias was first described by Sladen in 1889 as a subgenus of Asterias. Apparently its true relationship has not been suspected, because all species subsequently assigned to the group are in no way closely related. Hydrasterias diomedeae Ludwig” is the six-rayed fissiparous young stage of Sclerasterias alexandri His Hydrasterias species is a young stage of the same, or another Sclerasterias. Hydra- sterias richardi Perrier,” the specimens of which are very small, is probably also a six-rayed stage of a five-rayed adult asteriid. The history as shown by Sclerasterias alexandri and S. euplecta (Fisher) is briefly this: The young at first develop six rays. They divide into two halves of three rays each. Three new rays are regenerated. There is evidence that a second division may take place nearly at right angles to the first (since a resulting animal has one long and two short rays, while another in the same haul has two long and one short). After the last division, when the animal is still small, regeneration produces a five- rayed condition, which results in a symmetrical five-rayed adult. This is a case of asexual reproduction inasmuch as one egg may give rise to a num- ber of adults, as in Aurelia. Hydrasterias verrilli Fisher™ although superficially resembling Hydrasterias ophidion has four rows of tube-feet, a narrow oral angle, with several small pairs of postoral adambulacral plates in contact interradially, and apparently belongs in the Asteriinae. It is now the type of Tarsastrocles Fisher. * In H. sexradiata (Perrier) and H. improvisa (Ludwig) which I have examined, males in both cases. 1 Mem. Mus. Comp. Zoil., 1905, p. 242, pl. 34, fig. 204; pl. 35, fig. 206. 21 Exp. Sci. Travailleur et Talesman, 1894, p. 109, pl. 9, fig. 4. * Starfishes of the Hawaiian Islands, 1906, p. 1106, pl. 41, figs. 3, 3a, b. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 69 I had already set aside Pedicellaster sexradiatus Perrier and P. improvisus Ludwig as a generic group quite distinct from Pedicellaster, when the similarity of the first species to Hydrasterias ophidion Sladen occurred to me. At my request Dr. R. Kirkpatrick, of the British Museum (to whom I have been indebted repeatedly for information concerning types then under his care), examined the oral region of the unique specimen of Hydrasterias ophidion, made excellent photographs and sent a small piece of the dorsolateral integument with numerous pedicellariae. Doctor Kirkpatrick’s observations and photographs prove, as I suspected, that the first pair of postoral adambulacral plates are widely separated as in Pedicellaster. Indeed the alliance of Hydrasterias with Pedicellaster might be inferred from Sladen’s figure, showing clearly the biserial tube-feet and wide-meshed delicate skeleton. But it could not be satisfactorily established without knowledge of the structure of the oral angle. The relationship of Hydrasterias ophidion to H. sexradiata remains to be worked out. They are probably races of the same species, or may be the same species. Specimens of H. serradiata from latitude 37° north, longitude 27° west, 1,600 me- ters, however, have good sized spatulate, denticulate straight pedicellariae in the interradial region. The crossed pedicellariae of sexradiata are closely similar to those of ophidion which are figured herewith. (Pl. 27, fig. 8.) Hydrasterias improvisa (Ludwig) “4 was dredged by the Albatross at stations 3362, 3400, and 3407, east of Cocos Island and near the Galapagos Islands, in 1,175, 1,322, and 885 fathoms. It is a five-rayed form with quite distinct crossed pedi- cellariae, which, however, are of the same type as those of ophidion. (PI. 27, fig. 7.) Clark’s® record of improvisa from station 5675, 284 fathoms, southwest of San Cristobal Bay, Lower California, is based upon a specimen which is described in this work as Anteliaster coscinactis megatretus. Genus ANTELIASTER Fisher Anteliaster Fisupr, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 252. Type A. coscin- actis Fisher. Diagnosis.—Differing from Pedicellaster in the arrangement of the actinal plates, which are in one to three normal longitudinal series (not in transverse series with more numerous plates to a series distally than proximally), and in lacking prominent terminal claws on the jaws of the crossed pedicellariae; adambulacral armature, a transverse comb of two to five slender spinelets, conspicuously longer than any of the others, except the oral spinelets (which form a longitudinal series on each plate) ; large, spatulate, sometimes unguiculate straight pedicellariae may be present. Gonads opening ventrally. KEY TO KNOWN SPECIES OF ANTELIASTER a!. Abactinal papulae on rays; mouth plates larger. bi. Large hand-shaped unguiculate, straight pedicellariae; skeleton with three dorsolateral and two actinal series of meshes; spinelets with numerous terminal thornlets_--coscinactis Fisher. b2. No straight pedicellariae; skeleton very open, with two dorsolateral and three actinal series of meshes; spinelets with three or four terminal thornlets----------------- megatretus Fisher. 24 Mem. Mus. Comp. Zodl. vol. 32, 1905, p. 216. % Bull. Amer. Mus. Nat. Hist., vol. 82, 1913, p. 202. 70 BULLETIN 76, UNITED STATES NATIONAL MUSEUM a. No abactinal papulae on rays; mouth plates smaller. : 5 i bt, Adambulacral combs with proximally five spines; no straight pedicellariae. microgenys Fisher. b?, Adambulacral combs with two or three spines; spatulate oral straight pedicellariae. nannodes Fisher. ANTELIASTER COSCINACTIS Fisher Plate 29, Figures 1, 1a-le; Plate 35, Figure 6; Plate 36, Figure 4; Plate 37, Figure 3 Anteliaster coscinactis Fisumr, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 252. Diagnosis —Rays five, long, slender, flexible, very gradually tapered to a bluntly pointed extremity; disk small; body wall rather thin; spinelets very small, close-set alternating, on the rather large meshed skeleton, with small crossed pedicellariae; abactinal papular areas irregular (in equivalent of about three series); about three actinolateral series of regular, subquadrate meshes; two series of actinal plates; adambulacral spinelets longer than any of the others, proximally four or three, then two, in transverse series; large hand-shaped, unguiculate straight pedicellariae. R 63 mm.; r 9mm.; R=7r; breadth of ray at base, 7.5 to 10 mm. Description—The abactinal surface has somewhat the appearance of that of a deep-water Henricia, the pedicellariae and small spinelets standing in single file on the narrow, very irregular skeletal ridges. The meshes are large, not at all uniform in size, very irregular in form, and contain three to six papulae. The spinelets are quite delicate, 0.4 to 0.5 mm. long, while the interspersed crossed pedicellariae are 0.27 to 0.3 mm.long. Usually there is but one spinelet to a plate, but since the plates them- selves are small, the spinelets stand less than their own length apart, with usually one or two pedicellariae between. The form of the spinelets is best appreciated from figures. Both the marginal and actinal spines and pedicellariae are a little larger than the abactinal, and the spines are tapered and pointed. In contrast to the abactinal, the lateral and actinal papular areas form three (or two in smaller specimens) regular longitudinal series, broken here and there by slight irregularity, like that of a clumsily mended net. An analysis of the skeleton, of great importance for identification, reveals a very irregular carinal series of three, four, or even five lobed plates, joined by one to three intermediate ossicles. There are the equivalent of two dorsolateral series of + or Y shaped plates, joined by elliptical intermediate ossicles, forming the very irregular reticulum alluded to above. Then comes two series of -k-shaped marginal plates, the inferomarginals the more regular of the two, and between these and the adambulacrals are two series of actinals, the inner not fully developed. Transverse, elliptical ossicles join the three outer of these four series as shown in the figure. The outer series of actinals continue to within 10 mm. of the end of ray, and the inner series, varying on different rays, to well beyond the middle. The relatively long, slender, tapered, pointed adambulacral spines form a bristling cheveux-de-frise on the furrow margin. The spines stand in transverse combs, four on the first four or five plates, then three on the following six plates, then two for the remainder of the ray. Of these, the inner is a little shorter and slenderer than the outer, which is 2.5 to 3 mm. long. The second spine is slightly the longest, in the combs of three and four. The external end of the first adambulacral plate is rather widely separated from its vis-4-vis across the interradial angle. There are no small oe el oe ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 71 straight pedicellariae on the adambulacral plates, but occasionally a large spatulate unguiculate pedicellaria stands on the actinal surface of the proximal plates. The mouth plates (pl. 29, fig. 1) have the usual form and carry a longitudinal series of five slender spines, of which the two inner (actinostomial) are the shortest; and the outermost (just external to middle of plate) is subequal to the longest adjacent subambulacral. A short sixth spinelet stands on the furrow margin in a transverse direction to the outermost suboral. There is no trace of small straight pedicellariae on the mouth plates, but in one mouth-angle each plate carries a large unguiculate spatulate pedicellaria. The crossed pedicellariae are numerous and alternate with the spinelets on the skeletal net. Occasionally two stand between a pair of spinelets, and one to three are found on the membrane of most of the papular areas. They range in length from 0.27 to 0.4 mm., the largest being actinal, and are characterized by numerous teeth (about 10) on the vertical series of each jaw. (PI. 29, figs. 1c, 1d.) Straight pedicellariae: On the actinal plates near the interbrachial angle there is usually a single large spatulate pedicellaria with three or four long curved teeth. It resembles in miniature a pair of clasped hands and is 0.9 to 1 mm. long. Several of the same sort, but narrower and with sometimes only two teeth, stand on the proxi- mal adambulacral plates or on the outer end of the oral plates. There are no small lanceolate straight pedicellariae. (Pl. 29, fig. 1a.) Madreporic body fairly large, near margin. Anatomical notes—The gonads open in the interval between the inferomarginal and the actinal plates, about 6 mm. from the interbrachial angle. Each gonad con- sists of several small branched tufts, the lobules being irregular in form and unequal in length. The ampullae are rather large, not divided, and the tube-feet are in two series. A peculiarity of the species seems to be the entire absence of an interbrachial septum. There isno membrane nor continuation inward of the interbrachial skeleton. There is therefore a free space interradially between the interbrachial ridge and the inner border of the actinostome. Type.—Cat. No. E. 1421, U.S.N.M. Type-locality—Station 4427, 7 miles southwest of Point San Pedro, Santa Cruz Island, Calif.: 447 to 510 fathoms, black mud, rocks; April 14, 1904. Distribution.—Known only from the type-locality. ANTELIASTER COSCINACTIS MEGATRETUS, new subspecies Plate 29, Figures 2, 2a, 2b; Plate 35, Figures 5, 5a Pedicellaster improvisus Cuark, not Ludwig, Bull. Amer. Mus. Nat. Hist., vol. 32, 1913, p. 202. Diagnosis—Rays 5. R77 mm. (longest ray); r9mm.; R=8.5 + r; disk small; rays slender, weak, flexible. Differing from A. coscinactis in lacking straight pedi- cellariae, in having a more open skeleton with larger meshes (two dorsolateral series) slenderer plates, more delicate spinelets (with fewer terminal thornlets), and slenderer crossed pedicellariae. : Description—The skeleton is more open than in coscinactis. Along the side of the ray there are four longiseries of large quadrilateral meshes which are normally regular, although on some rays the longitudinal trabeculae disappear so that two or Tz, BULLETIN 76, UNITED STATES NATIONAL MUSEUM more meshes merge in a transverse way forming a very wide interval, extending occasionally from the superomarginal to the adambulacral plates. Bounding the four longiseries of meshes there are two series of slender, four-lobed marginal and three of actinal plates. These plates are connected, in transverse series, by a slender intermediate ossicle between the superomarginal and inferomarginal plates, between the latter and the first actinals, and sometimes between the first and second actinals. Intermediate ossicles appear sporadically in the longitudinal series, but not regularly and they all tend to disappear on the outer part of ray. There is an irregular series of slender-lobed, --form carinals, and between these and the similar superomarginal plates are two series of very large dorsolateral skeletal meshes, separated by an irregu- lar series of largely three-lobed plates. (Owing to the condition of the type, it is not possible to ascertain the constancy of this arrangement for all the rays.) These dorsolateral plates are connected with the carinals and superomarginals by slender intermediate ossicles. The primary plates and most of the intermediate ossicles bear a very small spinelet (pl. 29, fig. 2b) with three or four terminal points, 0.4 to 0.5 mm.long. These are a little more delicate and have fewer terminal points than those of coscinactis. The skeleton differs from that of coscinactis in having larger meshes, with slenderer lobes to the plates; two rather than three dorsolateral series of meshes; proximally three series of actinal plates (and papular areas). The dorsolateral and intermarginal papular areas have three to five papulae; the others, one or two. ; First 8 or 10 adambulacral plates carry a transverse comb of three, rarely four, very slender spines, the other plates two, equal in length to about four consecutive plates. They are similar to those of coscinactis but are slenderer. Each mouth plate carries five or six spines; one or two on the actinostomial end; a row of three or four in line with the larger actinostomial spine, reaches nearly to the outer end of the plate; sometimes there is a small spine as in coscinactis, on the margin and near middle of plate. The plates are not very different from those of coscinactis. There are no straight pedicellariae. The crossed pedicellariae are more tapered than those of coscinactis as viewed in profile, the exact difference being best appreciated by comparison of figures. (Pl. 29, fig. 2, 2a.) The largest ventral pedicellariae measure 0.45 mm. long; the dorsal 0.27 to 0.32 mm. Madreporic body very small, circular. Furrow narrow; tube-feet strictly biserial. Type—No. 32477, U.S.N.M. Type-locality.—Station 5675, off San Pablo Point, Lower California (27° 07’ 08’’ N., 114° 33’ 10’’ W.); 284 fathoms, green mud, fine sand; bottom temperature, 44.6° F. (March 15, 1911). Distribution Known only from type-locality. Remarks.—The type specimen, recorded by Clark (1913, p. 202) as Pedicellaster wmprovisus Ludwig, is larger than the type of coscinactis and has conspicuously larger skeletal meshes. The superomarginals are much nearer to the carinals than to the adambulacral plates. On the ray that is best preserved and most regular there are large subquadrate meshes between the carinals and adambulacrals; four of these series are between the superomarginal and adambulacral plates. It is not possible, of course, to ascertain how constant the differential characters will prove to be. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 73 Although this species resembles a large Hydrasterias improvisa (Ludwig), the latter lacks entirely the actinal plates which characterize even quite small Ante- liaster. Improvisa has numerous small straight pedicellariae on the furrow face of the adambulacrals. These are not found in any of the known forms of Anteliaster. ANTELIASTER MICROGENYS, new species Plate 30, Figures 1, la-le; Plate 35, Figure 3; Plate 36, Figure 1 Diagnosis —Rays 5, rather short, strongly inflated at base, bluntly pointed, recurved; disk fairly large; abactinal skeleton irregular with two rows of meshes, the outer rather elongate transversely; superomarginal and inferomarginal plates well spaced, with slender connecting ossicles between the two series; one series of actinal plates, mouth plates small, with two actinostomial and four larger superficial spines; adambulacrals with proximally five, distally three spines in transverse comb. No straight pedicellariae. R30 mm-+;r7mm.; R=4.31r; breadth of ray at base, 7 mm.; just beyond base, at widest part, 9 mm. Description—The abactinal surface might be described as of an indifferent Pedicellaster type, with the usual irregular skeleton, having, however, large trans- versely elongated meshes mostly devoid of papulae, except on disk. The spinelets, generally one to a plate, are a little thicker than usual, about 0.5 mm. long, somewhat tapered, and terminated by several points. (Pl. 30, fig. la.) Alternating with the spinelets, and occurring also on the membrane of the meshes, are numerous small pedicellariae about 0.3 mm. long. In alcohol, the spinelets and skeleton were covered by a thickish membrane. ‘The sides of the rays are characterized by the regular, rather widely separated marginal series, each plate bearing a single tapered spinelet slightly larger than the abactinal spinelets, and in addition most of the long inter- marginal ossicles of the proximal half of the ray carry also a small spinelet. A row of actinal spinelets, a trifle bigger than the inferomarginal spinelets, extends two- thirds to three-fourths the length of ray. Each intermarginal and actinal mesh (except near end of each series) has a papula. An analysis of the skeleton shows an irregular carinal series of four-lobed plates; proximally two dorsolateral longiseries of alternately A and y shaped plates joined in series by the arms. The handle is connected, respectively, to the carinals and supermarginals, usually by means of one or more slender ossicles. The superomar- ginals are joined to the corresponding inferomarginal by a slender, long ossicle, and the first few inferomarginals are similarly connected to the corresponding actinals by a short intermediate ossicle. (Pl. 30, fig. 1.) The adambulacral spinelets, 1.5 to 2. mm. long, are proximally five to a plate, in a transverse slightly curved comb. Beyond the basal third of the ray the number is quickly reduced to three which is maintained to the end. On one ray four is more usual than three. There is not much difference in the length of the spines of a comb; the median of three is likely to be the longest, and when there are four or five, the outermost but one is often the longest. The mouth plates are smaller than in coscinactis, and normally the spines cover the surface, overlying the first adambulacral comb, as that overlies the succeeding. The surface of the plates slopes sharply toward the mouth so that the two small actinostomial spinelets are directed fairly into it, or else across the mouth of the furrow. 74 BULLETIN 76, UNITED STATES NATIONAL MUSEUM The four suboral spines, similar in all respects to the adambulacrals, are close to the furrow margin in a sort of arcuate series. (PI. 30, fig. 10.) I can find no straight pedicellariae. The crossed pedicellariae (pl. 30, figs. 1d, le) are from 0.28 to 0.34 mm. long and are similar in general form to those of coscinactis but have usually fewer teeth in the vertical series of each jaw (six to eight as arule). The adambulacral and oral plates and spines are entirely devoid of pedicellariae. Madreporic body small, about two-thirds distance from center of disk to supero- marginals at interradius. Anatomical notes—The gonads open just ventral to the inferomarginal plates, 2.5 mm. from the interradial angle. Each ovary is a small globular mass. The skele- ton of each interradial angle is continued internally as a slight septum or buttress. The ampullae are single and the tube-feet strictly biserial. Type—Cat. No. E. 1422, U.S.N.M. Type-locality Station 2951, south of Santa Cruz Island, Calif., 33° 55’ 30’ N., 119° 55’ W.; 48 fathoms, fine gray sand; 1 specimen. Distribution —Known only from the type-locality. Remarks.—This species is readily separable from coscinactis by reason of the notably smaller mouth plates, larger combs of adambulacral spines, absence of straight pedicellariae, wider intermarginal space, and the presence of incipient interbrachial septa. The crossed pedicellariae have slightly fewer teeth in the vertical series of each jaw. The raysare considerably stockier than in coscinactis. Whether the absence of abactinal papulae from the rays is really characteristic of the species or only a specimen peculiarity can not be determined. Since the same peculiarity is found in nannodes, I believe it is an important character. The station number may not be correct, as the depth recorded is much less than usual for this genus. ANTELIASTER MICROGENYS NANNODES, new subspecies Plate 29, Figures 3, 3a—-3d; Plate 35, Figure 4 Diagnosis.—Differing from A. microgenys in having fewer, slenderer adambu- lacral spinelets, slightly different crossed pedicellariae, and in having, sometimes, oral, spatulate straight pedicellariae of conspicuous size. R 17 mm.; r 3.5 mm.; breadth of ray at widest part, 4 mm.; R=4.8+ r. Description.—The skeleton is very similar to that of microgenys, but on account of the small size of the specimen the intervals are smaller. There are two more or less interrupted dorsolateral series of meshes separated by the A and Y dorsolateral plates, but very few intermediate ossicles are present. As in microgenys there are no dorsal papulae except a few on disk. The intermarginal ossicles are developed proximally so that even in such small specimens the two series of marginal plates are well separated. A single longiseries of actinal plates, and above them one of papular areas, extend nearly to the middle of ray. Each intermarginal and actinal area contains one papula. The spinelets are very small, rather thick, tapered, and end usually in three or four points. They stand one to a plate, are 0.26 to 0.35 mm. long, and are well spaced, but the intervals are filled with pedicellariae which resemble those of micro- ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 75 genys. The teeth of the vertical series are usually less well developed, and the pedi- cellariae are, of course, smaller (0.18 to 0.22 mm. long; see pl. 29, figs. 3c, 3d, 3e). The first two or three adambulacral plates have three slender spinelets, the rest only two, conspicuously longer than the actinals and inferomarginals, which in turn are a trifle longer than the abactinal. The small oral plates each carry three or four spinelets in a series, and the type also has on the outer part of each pair (except one) a large spatulate straight pedicellaria with irregularly denticulate distal margin. These are not present in the other specimen. The spinelets are sheathed in a delicate watery membrane which almost disappears on drying. Madreporic body small, at the top of interbrachial sulcus. The gonads of the type, a male, are large lobulated organs which open a short distance from the interbrachial angle, just below an inferomarginal plate. The lobes of the gonad extend to the middle of the ray, and fill most of the proximal half of the ray coelom. Type.—Cat. No. KE. 1423, U.S.N.M. Type-locality— Station 4770, Bowers Bank, Bering Sea, 54° 31’ N., 179° 15’ E.; 247 fathoms; June 3, 1906; bottom not recorded. The bottom temperature at station 4769, very close to this locality, 244 fathoms, is 38.5° F.; gray sand, green mud. Distribution.—Known only from the type-locality. Remarks.—Two small specimens are a hazardous basis for a new subspecies, but they must be treated more formally than variants of the Californian species. Their relationship with microgenys was not at first appreciated, since the presence of large spatulate pedicellariae in one example suggested, rather, coscinactis. The structure of the dorsolateral and marginal skeleton, the form of the spinelets and crossed pedicellariae, and the small size of the oral plates are all more like microgenys than coscinactis. The absence of abactinal papule on the rays, although not surprising in such small examples, is nevertheless a characteristic also of microgenys. In coscinactis the abactinal papule extend up to the tip of the ray. While the fewer adambulacral spinelets is the most tangible difference separating nannodes from microgenys, the presence of spatulate straight pedicellariae is also probably of value, although these may be present on some specimens of microgenys. The crossed pedicellariae have rather fewer teeth in the vertical series of each jaw and the two or three distalmost are more strongly developed than in microgenys. Genus TARSASTER Sladen Plate 30, Figures 2, 3; Plate 31, Figures 1, 1a; Plate 37, Figures 1, la Tarsaster SUADEN, Challenger Asteroidea, 1889, p. 439. Type T. stoichodes Sladen.—FIsHER, 1923, p. 252. Diagnosis.—Rays 5, slender, tapering, subterete, constricted adjacent to small disk; no actinal plates on ray; inferomarginal plates with a prominent spine heavier than the adambulacral spines and forming a longiseries just external to them; inter- brachial marginals stout, firmly united but not especially enlarged; first pair of postoral adambulacral plates separated or else in partial contact on interradial line; adambulacral plates diplacanthid or both diplacanthid and monacanthid; straight pedicellariae lanceolate, not prominently spatulate or unguiculate; tube-feet quad- riserial proximally, biserial distally. Skeleton a close reticulum of three and four 76 BULLETIN 76, UNITED STATES NATIONAL MUSEUM lobed plates, rather irregular on dorsolateral area; carinals well marked, —- form; superomarginals + form, regular (not warped); abactinal and superomarginal spine- lets short, spaced, tubercular or mobile, one to several per plate; interbrachial septum small, almost wanting; gonads opening dorsally just above superomarginal plates. Remarks.—Tarsaster stoichodes, the type of the genus, was described by Sladen in the Challenger report (1889, p. 440) and was based upon a single specimen taken north of the Admiralty Islands in 150 fathoms. It was classified in the now defunct Stichasteridae because the dorsal plates were arranged in longitudinal series. A second species, 7’. distichopus (differing in having unguiculate pedicellariae and biserial tube-feet), was described by the writer from the Straits of Macassar, 400 fathoms (1919, p.590). In attempting to classify ““Sporasterias” mariana Ludwig, S. cocosana Ludwig and S. galapagensis Ludwig from the Pacific coast of Mexico and Panamic area, it became apparent that they were perhaps generically the same as Tarsaster distichopus Fisher. I have had the advantage of making direct comparison of speci- mens. All these species have the first pair of postoral adambulacral plates separated interradially (or else in slight contact by the adoral corners) and thus resemble Pedicellaster, where the separation is always complete and conspicuous. They all differ from true Pedicellaster in having a prominent longiseries of inferomarginal spines external to the adambulacral. Dr. R. Kirkpatrick, of the British Museum (Natural History), examined for me the type of Tarsaster stoichodes and made photographs of the oral angle. Doctor Kirkpatrick found, as shown by the photographs, that the first pair of postoral adambulacral plates are in partial contact; that is, they touch interradially by the adoral portion of the appropriate margin. In the other species which I have placed in this genus the plates are separated, but in Ampheraster an analogous condition exists; the plates may be either separated or in partial contact. In Ampheraster marianus the largest specimen has the plates in contact, the other smaller specimens have them separated. It has seemed best to segregate in Ampheraster those species which, while resem- bling Tarsaster, have conspicuous unguiculate straight pedicellariae, a predominantly monacanthid adambulacral armature, enlarged interbrachial superomarginal plates, and no accessory inferomarginal spinelet or tubercle. The latter, in the American species of Tarsaster, is a good recognition character and is constantly present in such distinct (perhaps subgenerically separable) species, as alaskanus and cocosanus. Sladen does not describe it in the type but in the photo- graph there appears to be an accessory inferomarginal spinelet above one of the major spines. In Tarsaster as here limited the superomarginal plates do not exhibit the curious instability characteristic of Ampheraster. The plates are of the conventional four- lobed pattern and form regular longiseries. The distal plates are occasionally a trifle warped. Tarsaster and Ampheraster are structurally in some respects intermediate between Pedicellaster and the simpler Asteriinae. The skeleton above the inferomarginals is very similar to that of typical Pedicellasterinae (which are now known to have some- times unguiculate straight pedicellariae). The crowding of the tube-feet, in Tarsaster, into two zigzag rows, or into four distinct series, follows a multiplication and shorten- ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 77 ing of the ambulacral ossicles by which alternate pores are squeezed out of line. All degrees of these are found in the Asteriinae. In Ampheraster, two species have a biserial arrangement of tube-feet, even to the base of the ray; the other three have the tube-feet quadriserial in various degrees. In Pedicellaster, Hydrasterias, and Peranaster the tube-feet are strictly biserial. These three genera have a considerable gap between the interradial border of the first postoral pair of adambulacral plates, sometimes even to the intrusion between these plates of the outer end of the combined mouth plates. In Tarsaster and Ampheraster this first pair of plates is either separated by a muscular symphysis (sometimes fairly broad) or else the adoral corners are in close contact. In Ampheraster marianus only the largest specimen has the plates in contact; in others they are separated. In A. atactus the plates are obviously in con- tact. In the large A. hyperoncus the plates are wellseparated. This feature thus runs the gamut from the condition in Pedicellaster nearly to that of the least specialized Asteriinae, apparently in correlation with the structure of the ambulacral plates which are quite Pedicellaster-like in A. hyperoncus and not at all so in marianus and atactus. KEY TO THE KNOWN SPECIES OF TARSASTER a!, Adambulacral plates diplacanthid, or the first few triplacanthid; abactinal crossed pedicellariae 0.26 to 0.32 mm. long. b!. Abactinal spinelets arranged in transverse series, the carinal and superomarginal plates with about 3 spinelets; oral plates each with 3 or more spinelets. c!. Spinelets cylindrico-conical, robust, erect; dorsolateral plates with 1 or 2 spinelets; adoral adambulacral plates touching by adoral corners; accessory inferomarginal spinelet not well developed; major inferomarginal spine lanceolate, flattened (150 fathoms, north CheyAT INIT Lyre Gs Necenes= eee ere ae serene ES Leese ot) eae See stoichodes Sladen. ce. Spinelets rather slender, tapering, not erect and stubby; dorsolateral plates with more often two or three spinelets; adoral adambulacral plates separated, accessory infero- marginal spine well developed; major inferomarginal spine terete, clavate, in length equal to about 1.2 to 1.5 plates; minor inferomarginal spine equal to or larger than the superomarpinalrspines see she ot res Pea eee oe we alaskanus Fisher. b. Abactinal spinelets not in transverse series, the carinal and superomarginal plates with one spinelet each; oral plates with two spines each; major inferomarginal spine lanceolate, flattened (1.5 plates in length), the minor, slenderer, shorter, and sharper than the blunt BUPECLOMATSMIBIGSDINELGtS =.= == = ea ee ee galapagensis *° (Ludwig) a’, Adambulacral plates diplacanthid, sporadically monacanthid, distals largely monacanthid, abactinal crossed pedicellariae about 0.36 to 0.38 mm. long; major inferomarginal spine robust, tapered, blunt, very slightly flattened, in length equal to 1.2 to 1.5 plates; minor inferomarginal spine about two-thirds as long, blunt or pointed, larger than the two or three small subcylindrical or clavate superomarginal spinelets (in transseries); abactinal spinelets similar, small (0.55 to 0.65 mm.), subclavate, erect, stubby, one or two on dorsolaterals, three on carinals; dorsolaterals irregularly spaced, not in evident transseries. (Guadeloupe, Woestulndies) = s25 Pier os ast Ae Soe a ape ea ng fascicularis 7 (Perrier) a3. Adambulacral plates monacanthid except first 9 or 10 which are diplacanthid; distal plates sporadically diplacanthid or rarely triplacanthid; abactinal crossed pedicellariae about 0.45 mm. long; abactinal and marginal spinelets short, very robust, tubercular, subcylindrical; the major inferomarginal spine sublanceolate, somewhat flattened (one plate in length); the minor spine, tubercular, rather smaller than the superomarginal spinelet. cocosanus *8 (Ludwig) % Sporasterias galapagensis Ludwig, Mem. Mus. Comp, Zodl., vol. 32, 1905, p. 240, pl. 34, figs. 202, 203; station 3404, south of Chatham Island, Galapagos Islands, 385 fathoms, rocks; bottom temperature 43.2 Fahr. ” Asterias fascicularis Perrier, Mém. sur les Etoiles de Mer (“Blake”), Nouv. Arch. Mus. d’Hist. Nat., ser. 2, vol. 6, 1884, p. 200, pl. 3, Guadeloupe, 309 fathoms. Data from type No. 1210. Mus. Comp. Zodl. 48 Sporasterias cocosana Ludwig, Mem. Mus. Comp. Zodl., vol. 32, 1905, p. 235, pl. 33, fig. 199; pl. 34, figs. 200, 201; station 3370 off Cocos Island, 134 fathoms, rocks, shells; bottom temperature 54.8 F. 64406—28 6 78 BULLETIN 76, UNITED STATES NATIONAL MUSEUM TARSASTER ALASKANUS, new species Plate 30, Figures 4, 4a-4d; Plate 36, Figure 3; Plate 37, Figure 4 Diagnosis.—Rays 5, slender, subterete, tapering gradually from a swollen base to a subacute tip; disk small marked off by a distinct constriction from ray; interbrachial angle sharp, closed; carinal plates forming a slight convex ridge; spinelets small, uniform, several to a plate, arranged (with numerous crossed pedicellariae) in trans- verse bands, between which are narrow transversely oriented papular areas; infero- marginal plates with two spines the upper uniform with the general spinulation, the lower enlarged, subclavate, obtuse, about 2 mm. long; adambulacral plates dipla- canthid, except 8 or 10 proximal triplacanthid plates; oral plates with five spines, of which two stand on actinostomial margin; straight pedicellariae, small, broadly lanceolate, confined to oral and adambulacral plates; tube-feet proximally four- ranked distally biserial. Differing from 7’. galapagensis (Ludwig) in having several mobile spinelets on the abactinal plates; subterete, clavate, blunt major infero- marginal spines (instead of almond-shaped ones); five instead of two oral spines; and no straight pedicellariae on the abactinal and marginal plates. R 67 mm.;r 6.5 mm.; R=10 r; breadth of ray at base, 8 mm.; at widest part, 12 mm. Description—The skin is relatively thick and completely obscures the outlines of the plates, which, however, are slightly indicated by shallow transverse depressions denoting the papular areas. The carinal plates form a rather broad, slightly convex ridge. The numerous small, slightly tapered, thorny tipped spinelets (about 0.8 to 1. mm. in length) are arranged in somewhat irregular consecutive transverse bands or ranks, which are separated by the transverse depressions noted above. The spinelets of the abactinal and superomarginal plates have the appearance of being of nearly uniform size, blunt, upward of three or four to a plate, and accompanied by numerous crossed pedicellariae, which, being largely absent from the papular areas, accentuate the transverse arrangement of the spinelets. The superomarginal plates are set off by a very slight longitudinal furrow on their upper margin and each plate carries about three spinelets in a vertical series, the consecutive series being rather close on account of the considerable overlapping of the plates. The inferomarginal plates which closely join the adambulacral series (without any actinal plates between) carry usually two spines in a transverse series. The inner is heavy, clavate, blunt, about 2 mm. long, and situated close to the outer adambulacral spine. Occasionally two subequal slightly smaller spines take the place of the larger inner spine. The second spine is about half as long, much slenderer, and is similar to the lower superomarginal spinelet from which it is spaced a little more than its own length. This outer spinelet forms a longitudinal series separated from the superomarginals by a slight furrow and is in no other way differentiated from the general spinulation. The inner enlarged spine forms a prominent longiseries just external to the bristling adambulacral spines. On a number of plates a second accessory spinelet makes its appearance. The skeleton is characterized by more compactness than that of other species, the skeletal meshes being smaller and the plates, especially the dorsolaterals, larger. The marginal plates are very firmly imbricated, the superomarginals being four-lobed, while in the inferomarginals, the ventral, or adambulacral, lobe is pretty much sup- pressed. The carinals are four-lobed and very firmly imbricated. ‘The dorsolaterals se ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 79 are very irregular. There are about three series of dorsolateral skeletal meshes: A series of larger meshes (or alternating larger and smaller) adjacent to the carinals; a similar series adjacent to superomarginals; between these a very irregular series of quité small intervals. Papulae numerous abactinally, arranged in transverse rows conforming to the trend of the skeletal intervals; intermarginal papular areas small, about one papula to an area. First 10 or 12 adambulacral plates are triplacanthid, the rest diplacanthid, the spines, in close transverse series, being slender, terete, blunt, about 2 mm. long. The outer spine of the diplacanthid plates is commonly a shade longer and stouter than the inner, while that of the triplacanthid plates is slenderer, tapered, and sharp. The spines of the first 10 or 12 plates are a trifle longer and slenderer than the others. Rarely a proximal plate has a small fourth spinelet. The mouth plates are rather broad and carry two slender actinostomial spines (the inner the longer and subequal to or a little longer than the median suture), and three longer, slender, suboral spines—two parallel to suture and one near outer fur- row corner. There are sometimes one or two small, toothed, lanceolate or lanceolate- obtuse, narrow-jawed straight pedicellariae on actinostomial margin. The first postoral adambulacral plates are not joined by the interradial ends, but there is a rather conspicuous interval between them. (PI. 30, fig. 4.) Crossed pedicellariae numerous, similar to those of J. galapagensis (Ludwig) and much smaller than the pedicellariae of 7. cocosanus (Ludwig); length about 0.3 mm. ‘They are found on all plates except the oral and adambulacral, and tend to form transverse groups abactinally. They are generally absent from the papular areas. Small lanceolate straight pedicellariae (about 0.45 mm. long) occur along the furrow margin. The jaws are narrow and tapering. Larger ones with a few small terminal teeth occur on the oral plates sparingly. (See pl. 30, fig. 2, stoichodes; fig. 3, cocosanus; pl. 31, fig. 1, galapagensis.) Madreporic body large (diameter 2.5 mm.) situated on the margin of the small disk. Furrow rather narrow (3 mm.); tube-feet quadriserial along the proximal third of furrow, biserial distally. Ambulacral pores in two very zigzag series on proximal fourth of furrow, and, in this area, very narrow and slit-like; on remainder of ray they form two straight series and are more broadly elliptical. Type.—Cat. No. E. 1424, U.S.N.M. Type-locality Station 4230, off Indian Point, vicinity Naha Bay, Behm Canal, southeast Alaska; 240 to 108 fathoms, rocky; bottom temperature, 42.4° F. Remarks.—T. alaskanus differs from T. galapagensis (Ludwig) in several impor- tant particulars. I have examined the type of galapagensis which is quite small (R 23 mm.). It has solitary, tubercular, heavy, abactinal and superomarginal spinelets like those of T. cocosanus (Ludwig), and its major inferomarginal spine is flattened and lanceolate, somewhat almond-form. The oral plates have but two spines, while the numerous abactinal and marginal straight pedicellariae are absent in alaskanus. Both species have diplacanthid adambulacral plates. In galapagensis a few of the proximal plates have a third smaller spinelet. 80 BULLETIN 76, UNITED STATES NATIONAL MUSEUM T. cocosanus, the types of which I have examined, differs from alaskanus in most of its details. The abactinal and superomarginal spinelets are short, tubercular, cylindrical and round-tipped; the crossed pedicellariae are much larger (0.38 to 0.45 mm. long); there are narrowly spatulate, small, toothed straight pedicellariae on the sides of the ray (and narrower-jawed ones on the furrow margin); the larger infero- marginal spine is somewhat flattened and lanceolate, while the smaller is subtuber- cular; the adambulacral plates are monacanthid, except about the first 10 and some near the tip of ray which are diplacanthid; the oral plates are diplacanthid. T. fascicularis (Perrier) is a large species comparable in size with alaskanus (R 57 mm.; r9mm.). It differs in most of its details. The adambulacrals are dipla- canthid and monacanthid, while the abactinal spinelets are shorter, stubbier, sub- clavate, erect (0.55 to 0.65 mm. long), and are not arranged in evident transverse lines except on the carinal and superomarginal plates. The abactinal crossed ped- icellariae are about 0.36 to 0.38 mm. long. Genus AMPHERASTER Fisher Ampheraster Fisoer, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 253. Type, Sporasterias mariana Ludwig. Diagnosis —Rays five, slender; disk small; abactinally resembling Pedicellaster ; closely related to Tarsaster but differing therefrom in having large, narrowly or broadly spatulate, prominently unguiculate, straight pedicellariae; an enlarged pair of inter- brachial superomarginal plates overlapping a pair of firmly united sometimes enlarged, corresponding inferomarginals, the quartet forming a very firm interbrachial skeleton; no accessory inferomarginal spinelet; monacanthid adambulacrals (sometimes partly diplacanthid); more open skeleton with larger dorsal meshes; a tendency to warped, four-lobed superomarginals. Skeleton similar in essentials to that of Tar- saster but in some species the superomarginal plates are in part three-lobed and in part warped four-lobed, and there is a tendency to irregularity in the marginal skeleton; postoral adambulacrals well separated or in partial contact, both conditions being found sometimes in different ages of the same species; no actinal plates (except an interradial rudiment; gonads opening dorsally, just above superomarginal plates; tube-feet biserial throughout, quadriserial proximally, or quadriserial throughout. Remarks.—The difficulties encountered in classifyiug the species of this genus have been indicated in the discussion of Tarsaster. The differences between marianus with its strong quadriserial tube-feet and hyperoncus with biserial feet and pores may seem at first glance of generic value. But A. chiroplus has characteristics of both species. Its proximal tube-feet are quadriserial and its oral plates and first pair of adoral adambulacral plates are nearer those of marianus. Its abactinal skeleton and three-lobed marginals resemble those of hyperoncus. If these last characters are given precedence and chiroplus is ranged with hyperoncus in a special subgenus, difficulty arises because the mouth plates and enlarged first superomarginals of chiroplus are more like those of marianus (as are the tube-feet), while a further complication arises from atactus which is not at all like hyperoncus except in having three-lobed, and warped four-lobed, superomarginals. The character of the marginal plates is therefore of value only when taken in combination with other features. It has been prominently used in the diagnosis ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 81 and key because in dried specimens it is fairly easy to recognize. It must be used with caution because since the tendency to warping of distal superomarginals is apparent even in Tarsaster (and in other genera less closely related), the effect may be due to growth strains. In chiroplus, however, the curiously formed four-lobed plates are, at least sometimes, due to the fusion of two three-lobed ones. The conspicuous, unguiculate, often spatulate hand-shaped pedicellariae and the enlarged interbrachial marginals of Ampheraster will serve as differentiating char- acters, while the absence of an accessory inferomarginal spinule will further aid in placing the species. KEY TO THE KNOWN SPECIES OF AMPHERASTER a’, Adambulacral plates monacanthid to tip of ray. b!. Superomarginal plates normally four-lobed, + form (sometimes slightly warped), imbricated in a regular series; dorsolateral skeleton with three or four series of meshes on either side of the carinal plates; tube-feet strongly quadriserial____--_-__- marianus (Ludwig). 62. Superomarginals largely three-lobed (or, if four-lobed, warped), imbricated in a zigzag series; dorsolateral skeleton with two series of meshes on either side of the carinal plates. c!. Tube-feet biserial throughout the ray, the ambulacral pores broadly elliptical, in straight series; straight pedicellariae much compressed, large, unguiculate; mouth plates PYOAG a eee ete ee ees ee ae Oe oe ee ee eee hyperoncus (Clark). c. Tube-feet quadriserial on proximal half of ray, the ambulacral pores narrowly elliptical, in zigzag series proximally; straight pedicellariae very large, broadly spatulate, with three or four curved, interlocking tines; mouth plates narrow_------ chiroplus Fisher. a*, Distal adambulacral plates diplacanthid; tube-feet quadriserial; marginal skeleton somewhat irregular, the superomarginals usually three-lobed, sometimes warped four-lobed; straight pedicellariae broadly spatulate with three or four coarse, curved, interlocking tines, spinelets conical, rough; dorsolateral skeleton with two series of skeletal meshes distally on either side of the carinal plates; proximally there may be three or four irregular meshes between carinals and superomarginals but not in serial order___-_----------------- atactus Fisher. a®. The first six or eight adambulacral plates diplacanthid, the rest monacanthid; abactinal and marginal spinelets, one to a plate, slender, tapered; dorsolateral skeletal meshes in three longiseries proximally, two distally; superomarginals four-lobed more or less warped; tube-feet strictly biserial throughout the ray; oral plates with one actinostomial and two suboral spines; unguiculate straight pedicellariae (0.8 or 0.9 mm. long) on furrow margin and oral plates; (400 fathoms, Straits of Macassar)-_----~_---------- distichopus (Fisher). AMPHERASTER MARIANUS (Ludwig) Plate 31, Figure 2, 2a—2/; Plate 32, Figures 1, 1a; Plate 35, Figure 1; Plate 38, Figures 1, 2, 3, 4. Sporasterias mariana Lupwia, Mem. Mus. Comp. Zodl., vol. 32, 1905, p. 231, pl. 33, figs. 194-198. Ampheraster marianus Fisner, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 253. Diagnosis.—Rays five. R76 mm.; r10mm.; R=7.6r; breadth of ray at base 10 mm. (slightly inflated beyond base); rays very gradually tapered to a pointed extremity; abactinal surface arched, actinal surface subplane, accentuated by the single series of acicular, usually horizontally directed inferomarginal spines; skeleton and spines covered by a thickish skin; skeleton open; about eight longitudinal series of abactinal meshes, subdivided by a straight series of carinal plates; spinelets mostly one to a plate, small, rough, conical; intermarginal papular areas rather large, subquadrate; adambulacrals monacanthid; numerous narrowly spatulate, unguiculate, straight pedicellariae; tube-feet four-ranked; furrows wide. Description.—The carinal plates are easily distinguishable and are imbricated directly, that is, without intermediate ossicles, into a fairly straight series, which 82 BULLETIN 76, UNITED STATES NATIONAL MUSEUM forms a slight ridge. The dorsolateral area is broad. In fully grown specimens the plates are so arranged that there is one longiseries of broad papular areas, or meshes, adjacent to the carinals and another adjacent to the superomarginals, while between the two there is a double row of much smaller irregular or lozenge-shaped areas, the meshes of each series of the four dorsolateral series alternating with those of adjacent series. (Pl. 32, fig. 1.) Ludwig” (pl. 33, fig. 195) indicates only three dorsolateral series of papular areas, but two of his cotypes which I have clearly show four at the base of ray (R 40 mm.). The dorsolateral plates are three or four lobed and are a little smaller than the carinals. The latter are a trifle smaller than the four-lobed superomarginals, which are strongly imbricated into a regular series, fairly low on the side of the ray. The distal superomarginals although four-lobed are “‘warped” out of shape so that the dorsal lobe is advanced further distad than the ventral, a feature often exaggerated in other species of this genus. The proximal plates do not as a rule show this very markedly. (Pl. 32, figs. 1, la.) The inferomarginals, also strongly imbricated, are a little larger than the superomarginals and are jux- taposed to the adambulacrals. There are a few inconspicuous intermarginal ossicles at the base of ray. In the interbrachial angle the second superomarginal is conspicuously enlarged and is firmly joined to the second enlarged plate of the adjacent ray. The lower end of this pair of interbrachial plates overlaps a pair of similarly enlarged inferomarginals. The four constitute a very firm interbrachial skeleton. The joined pair of jirst superomarginals continue the interbrachial skeleton upward to the primary interradial plate of the disk. The plates of ray have mostly one spine each. By reason of the open skeleton the spines are well spaced, and are short, stout, tapered, pointed, rough, and in length usually about half the greatest diameter of the plate. The superomarginal spines are scarcely different from the abactinal but are sometimes much blunter, In the largest specimen (station 2896) the abactinal spines are, relative to the plate, shorter than in small examples, and measure about 0.7 to 0.9 mm. long. The acicular, pointed, outwardly directed, inferomarginal spines stand on a prominent convexity of the plate and are as long as 2 or 2.5 inferomarginal plates, slender, but robust, in smaller specimens, heavier and slightly flattened in the large ones. A few of the esas plates in the largest specimens may carry a second smaller spine above the rst. The large adradial papular areas contain five or six papulae proximally; the smaller intermediate, dorsolateral areas have about three; the supramarginal four or five, the intermarginal, four to six. The adambulacral plates are small (30 to 32 corresponding to the first 10 spinif- erous inferomarginals) and carry a slender, acicular spine equal to the length of about four consecutive plates. Behind the mouth plates the first pair of adambula- cral plates is separated by a muscualr symphysis, fairly wide in small specimens, gradually narrowing with age, until in the largest specimen (station 2876) the plates touch by the corners nearest the mouth plates. In one of Ludwig’s cotypes (station 3425), R 40 mm., the plates are separated by a space as wide as the length of the first adambulacral. In a slightly smaller specimen from station 2980 (southern Califorina) * Mem. Mus. Comp. Zodl., vol. 32, 1905. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 83 the plates are separated about as widely, but in another (station 4427), a trifle larger, the symphysis is much narrower than the length of the first plate. I think there is a tendency for the northern specimens to have a slightly narrower symphysis than the southern. The structure of the first pair of adambulacral plates is of interest here, because in Pedicellaster and close allies (having five or six rays) the first adambulacrals are not in contact back of the mouth plates, whereas in the Asteriinae one pair at least, usually several, are in contact, forming the so-called adoral carina. In this species We really find a transition between the two types of structure. The fairly large mouth plates carry, on the actinostomial margin, either one or two acicular spines and a straight pedicellaria with usually two teeth to the jaw. On the surface are one or two spines similar to the adambulacrals, and sometimes a pedicellaria. There may be, thus, two to four spines on each plate. (Pl. 31, figs. 2, 2a.) The crossed pedicellariae are scattered on the skeletal meshes and are rather lacking in striking features. In profile the vertical series of teeth show usually about six or seven rather irregular dentations. Length, 0.32 to 0.36 mm. (PI. 31, figs. 2b, 2c.) The pedicellariae of Ludwig’s types agree in size and detail. The straight pedicellariae are of the narrow-spatulate, unguiculate type with generally two to four small curved teeth to each jaw tip. (PI. 31, figs. 2d, 2e.) They are scattered over the surface of the body and along the furrow margin from the inner end of the oral plate to the end of the ray. The abactinal show greatest diversity in size and form and usually have four teeth; the furrow pedicellariae are relatively less spatu- late, with two or three teeth, as a rule (0.9 to 1.25 mm.). The furrow is broad (0.5 r), with rather crowded, four-ranked, tube-feet, which only at the end of the ray become two-ranked. The ambulacral pores are not at all in straight but in two distinctly zigzag series, which straighten out only at the end of the ray when the furrow narrows. Madreporic body small, near the margin, and surrounded by a circle of spinelets. Anatomical notes—The gonads open dorsally near the upper margin of the second superomarginal plate (in the one specimen dissected). The ovary consists of four or five elongate lobes; eggs large. Stomach spacious, without distinct dorsal and ventral parts; coecum large, sac-like. Ampullae large, not bilobed. No Polian vesicles. Type—Cat. No. 34407, U.S.N.M. Type-locality Station 3425, near Tres Marias Islands, Mexico, 21° 19’ N., 106° 24’ W.; 676 fathoms, gray sand; bottom temperature, 39° F. Distribution —From the Tres Marias Islands, Mexico, to Washington (47° 29’ 30’ N.), 277 to 676 fathoms; temperature range, 37.9° to 42.8° F. Specimens examined.—Thirteen. 84 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Specimens of Ampheraster marianus examined Bottom) Num- tem- | ber of pee Locality Depth | Nature of bottom Sara lesriacl® Remarks ature | mens 2890 | Off Oregon, 43° 46’ N., 124° 57’ W__----------------- OT Gray Sand —s=——casene 42.2 1] U.S.N.M. 2896 | South of San Miguel Island, Calif-__..-.------------ 376 | Yellow mud_-_-_------- 42.8 1 Do. 2980 | Southeast Santa Cruz Island, Calif___.--- 2 603 | Green mud_-- 38.9 1 Do. 3070 | Off Washington, 47° 29’ 30” N., 125° 43’ W__ Ee 6386 Ee22 Omens ee 37.9 1 Do. 3425 | Tres Marias Islands, Mexico-_----.------------------- 676 | Gray sand 39 3 | Types. 4407 | 3.2 miles southwest of southeast point Santa Catalina | 478-600 | Gray sand, rocks___---_|_------- 1 | Albatross, 1904. Island. 4497 | 7 miles southwest Point San Pedro, Santa Cruz | 447-510 | Black mud, rocks_--_-|-------- 5 Do. Island. Remarks.—This very distinct species combines in a curious manner the appear- ance of Pedicellaster when viewed dorsally with that of Myxoderma when viewed ventrally—but a Myxoderma with uniform monacanthid adambulacrals. If the unique specimen of Ampheraster hyperoncus (H. L. Clark) *°is typical of the species, it is sharply separated from marianus by having strictly biserial tube-feet, even the ambulacral pores being biserial. I have examined this specimen which has R 68 mm.,r 7mm. There are only two series of very large dorsolateral skeletal meshes (four in all) which are clearly indicated by Clark’s figure. The superomar- ginal plates are very unusual inform. Instead of being regularly + form, the proximal plates are Y-shaped, while the rest might be described as similar to two Y’s joined by fusing the handles. (See Pl. 32 fig. 4.) Interpolated among these is an occa- sional Y-shaped plate. The superomarginals of hyperoncus are well spaced from the inferomarginals, most of the intermarginal papular areas being broader than long. AMPHERASTER CHIROPLUS, new species Plate 31, Figures 3, 3a-3d; Plate 32, Figure 2; Plate 35, Figure 2; Plate 37, Figure 2 Diagnosis.—Rays five. R 33 mm.; r 5 mm.; R=6.6 r; breadth of ray at base, 6mm. Disk small; rays slender, slightly swollen, gradually tapered; skin rather thick; distally two series of large skeletal meshes on either side of the carinal plates; proximally the biserial order is broken and there may be but one broad mesh; supero- marginal plates three-lobed, forming a zigzag series; spinelets very small, rather widely spaced; adambulacrals strictly monacanthid, the spines rather long and slender, subequal to the slightly stouter inferomarginal spines; straight pedicellariae, very large, spatulate, unguiculate, the shank constricted; crossed pedicellariae in profile broader distally and blunter than in A. hyperoncus or A. atactus; tube-feet quadriserial proximally. Description.—The abactinal skeleton consists, distally, of four longiseries of meshes and proximally, irregularly of two or four. When there are only two each mesh extends from the series of fairly regular four-lobed carinal plates to the superomar- ginals The dorsolateral plates are generally regularly Y and A form, distally, form- ing on either side a zigzag series; but on the proximal half of the ray they are not regular. The superomarginal plates are usually the same shape as the distal dorso- 40 Pedicellaster hyperoncus H. L. Clark, Bull. Amer. Mus. Nat. Hist., vol. 32, art. 8, 1913, p. 201, pl. 44, figs. 3 and 4; station 5645 southwest of San Cristobal Bay, west coast of Lower California, 284 fathoms, bottom temperature, 44.6° F. ’ ( : ‘ Rie as ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 85 laterals, and are unlike the carinals and inferomarginals. They form a zigzag series and occasionally, as shown in the figure, one of the plates is four-lobed, as if con- sisting of two fused plates. This type of superomarginal plate is present in Am- pheraster hyperoncus (Clark), and A. atactus, especially distally, since in that species the proximal plates are sometimes normally four-lobed. (See Pl. 32, fig. 2.) If all the superomarginal plates were regularly A and Yy form there would be twice as many as in the inferomarginal series, since it is only the alternate, Y-form, plates which overlap the ascending lobe of the inferomarginals. The inferomarginals are normal, the lower lobe, which joins the adambulacral plates, being very short. As shown in the figure, there are sometimes two intermediate dorsolateral ossicles between the primary plates, and proximally there is a rather long intermarginal ossicle. There is a quartet of enlarged superomarginals in the interbrachium, the first pair lying outside the primary interradial plate; the second pair is in line with the regular series and the lower ends overlie a pair of enlarged inferomarginals. Intermarginal papular areas have proximally two papulae and the dorsolateral, four or five in the smaller areas and about twice as many in the large. The skin is rather thick and pulpy, pretty well hiding the skeleton until dried. The spinelets are small, solitary, widely spaced, not very slender, tapered, bluntly pointed, and terminally prickly; length, abactinal, 0.4 to 0.5 mm. long. The supero- marginal are not different from the abactinal spines, but the solitary inferomarginal spines are, as usual, much longer (1.7 mm. proximally), terete, slender, bluntly pointed, a little stouter than the single, subequal, adambulacral spines. The latter are always one to a plate, very slender, terete, blunt. There are 29 adambulacrals to 10 proximal inferomarginals. The first adoral pair of adambulacrals do not meet interradially. Oral plates narrow with a huge unguiculate pedicellaria as long as the plates on the actinostomial end. There are two slender, slightly tapered, suboral spines. The straight pedicellariae are relatively huge, with broad spatulate jaws and four or five curved tines. The proximal part of each jaw is narrowed as a rule. They are very conspicuous and are scattered over the abactinal, marginal, and adam- bulacral plates, a few overhanging the furrow, and four guard the actinostome. The length is 1.1 to 1.25 mm. Crossed pedicellariae scattered, not so numerous as in A. atactus or A. hyperoncus. Only one to three occur on the superomarginals and usually none on the inferomar- ginals, except sporadically at very wide intervals; none on the adambulacrals. The pedicellariae measure 0.30 to 0.36 mm. long and differ in form from those of hyper- oncus and atactus, being much broader distally (as seen in profile), less tapered, with fewer teeth than in atactus. Madreporic body small, near the margin, and attached to a very regular penta- gon of disk plates. Furrow fairly broad proximally, where the tube-feet are four-ranked; distally they become biserial. The series of ambulacral pores are not nearly so straight as in hyperoncus, but are decidedly zigzag proximally, though distally they straighten out. The pores themselves are narrow elliptical while in hyperoncus they are broadly elliptical. 86 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Anatomical notes.—The gonads, which are small with large eggs, open just above the third superomarginal (in the single case observed). Each ovary is subdivided into five lobes. Type.—Cat. No. E. 1425, U.S.N.M. Type-locality—Station 4427 7 miles southwest of Point San Pedro, Santa Cruz Island, Calif.; 447-510 fathoms, black mud, rocks. Remarks.—This species may be distinguished from hyperoncus Clark by the form of the straight pedicellariac. In hyperoncus these are never broadly spatulate, but, on the contrary, are much compressed, lanceolate in profile, and the ends of the jaws are hooked. Furthermore, in hyperoncus the tube-feet are biserial and the ambulacral pores are broadly elliptical, less slit-like. Chiroplus differs from atactus in the form of the crossed pedicellariae, in having a more lax, open, abactinal skeleton, and a broader intermarginal area, with larger skeletal meshes, and proximally intermarginal secondary ossicles. Atactus has a rather rigid skeleton, that of chiroplus is flexible; atactus has on the distal plates usually two adambulacral spines; chiroplus never more than one. The madreporite of atactus is relatively larger than in chiroplus. The difference in the crossed pedicellariae is quite striking, and as these are generally very conservative as regards their form, I think they are of considerable value for identification. A comparison of figures will show that the crossed pedicel- lariae of hyperoncus and atactus are more nearly alike. The straight pedicellariae of chiroplus appear very large, as they are actually as big as in the very much larger specimen of atactus. Whether they increase further in size is not known. AMPHERASTER ATACTUS, new species Plate 31, Figure 4; Plate 32, Figures 3, 3a-3b; Plate 38, Figure 5 Diagnosis.—Rays five. R 60 to 65 mm.; r 9 mm.; breadth of ray at base, 10 mm.; R=6.6 to 7.1 r. Rays stout, slightly inflated, tapered from broadest part just beyond base; superomarginals actinolateral in position; intermarginal channel narrow. Spinelets short, conical, rough, rigid, uniformly rather widely spaced; inferomarginal spines about as long as and a little stouter than adambulacral spines, which stand one to a plate except near end of ray where there are two; straight pedi- cellariae, large, broadly lanceolate, with three or four strong claws to each jaw. Dif- fering from A. marianus in having minutely thorny spines, smaller marginal spines, narrower intermarginal channel, mostly three-lobed superomarginals, diplacanthid distal adambulacrals, and larger and differently formed straight pedicellariae. Description.—The skeleton of this species differs from that of marianus in having a broader dorsolateral region, with fewer, larger, and more irregular openings, a less regular and less prominent carinal series, narrower intermarginal region, with less regular, generally three-lobed superomarginal plates. The carinals have very short lobes and proximally the arrangement is very irregular. It is rather difficult to analyze the dorsolateral skeleton precisely. Distally, on each side of the carinal plates there are two series of broad meshes separated by a longiseries of Y and A shaped plates, which becomes more and more irregular toward base of ray. On the proximal half or two-thirds of ray the region between this primary dorsolateral series and the superomarginals widens much more rapidly than the adradial band of meshes. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 87 In this wider region a second series of dorsolateral plates extends in great disorder for half or two-thirds the length of ray. The exact number of proximal dorsolateral series of meshes is therefore not easy to determine; theoretically there should be three on each side. The superomarginals are mostly three-lobed (except proximally where irregular four-lobed plates occur irregularly), the descending lobe being short and imbricated directly to the upper lobe of the inferomarginals. The intermarginal papular areas are small and roundish. The quartet of interbrachial marginal plates is less conspicuous than in marianus. The abactinal and superomarginal spinelets are short (0.9 mm.), rough, conical, and sharp or bluntly pointed, well-spaced, one to a plate, and interspersed with numer- ous uniformly distributed crossed pedicellariae and a few broadly spatulate unguiculate straight pedicellariae. Inferomarginal spines, one to a plate, terete, rough, scarcely tapered except near tip, bluntly pointed. They are shorter than in marianus, being only about as long as the adjacent adambulacrals, although about 1.5 to 2 times their diameter. They do not stand out in a prominent actinal fringe. The larger abactinal areas have five to seven papulae; the smaller two or three; the intermarginal, one or two. The adambulacral plates are monacanthid, with here and there a diplacanthid plate; the distal 20 or 30 plates, which are small, are regularly diplacanthid. The spines are slender, terete, and rough near the bluntly pointed tips, and the longest proximal ones are equal to the length of five consecutive plates. Twenty-eight or thirty adambulacral plates correspond to the first ten spiniferous inferomarginals. The first postoral plate touches the companion plate of the adjacent ray, while the second pair nearly touch in one angle. The width of the combined oral plates is less than in marianus, and the ventral surface of each plate is only wide enough to carry a longiseries of two or three slender spines a little shorter than the first few adambulacrals. A single unguiculate pedi- cellaria stands on the truncate actinostomial end of the mouth angle. Crossed pedicellariae numerous, uniformly scattered on abactinal plates; few intermarginally and on the inferomarginals. They are similar in form and size to those of marianus, but in profile are a trifle more tapered and have a few more teeth in the vertical series (upwards of 11). Length 0.31 to 0.36 mm. The straight pedicellariae, which are fewer than in marianus, are found principally on the inferomarginal plates, are about 1.25 mm. long, very broadly spatulate, with three or four prominent curved claws. The pedicellaria is larger and broader, with coarser, longer, teeth than in marianus. They are absent from furrow face of adam- bulcral plates. Madreporic body prominent, 3 mm. in diameter, situated near margin. Ambu- lacral furrow rather wide, but less so than in marianus. Tube-feet in four series proximally, reduced to two zigzag series on outer half of ray. Gonads (ovary) similar to those of marianus, opening on the upper edge of the second (first spiniferous) superomarginal. Type.—Cat. No. E. 1426, U.S.N.M. Type-locality.—Station 4341, 3 miles southwest of South Coronado Island, vicinity of San Diego, Calif.; 266 to 323 fathoms, gray sand, black specks; bottom temperature, 42° F. Distribution.—Known only from the type-locality. 88 BULLETIN 76, UNITED STATES NATIONAL MUSEUM Remarks.—Although the presence of three-lobed superomarginal plates and broadly spatulate hand-shaped pedicellariae seems to ally atactus rather closely with chiroplus, I think it is perfectly distinct. It is found in shallower water than is chiroplus. j Subfamily LABIDIASTERINAE Verrill, emended Labidiasterinae VErriuu, Shallow-water Starfishes, 1914, p. 26.—FisHEr, Starfishes of the Philippine Seas, ete., 1919, p. 492; Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 249. Rays numerous (9-45), long, slender; inferomarginal spines prominent, single, enveloped in a sheath (carrying on the usually expanded distal surface a conspicuous wreath of crossed pedicellariae) ; abactinal skeleton either very open, with large squar- ish meshes, or else abortive with scattered independent plates; crossed pedicellariae in abactinal spinal wreaths or thick ruffs; no actinal plates; gonads two to each ray, opening upon the side a short distance from base; tube-feet numerous, biserial to quadriserial, each with a single ampulla. Remarks.—This rather isolated subfamily contains three genera: Coronaster Perrier (including Heterasterias Verrill), Rathbunaster Fisher, and Labidiaster Liitken (including Labidiastrella Verrill). A short discussion of their relationships is con- tained in Fisher, Starfishes of the Philippine Seas, 1919 (p. 492). There the subfamily is classified in the Pedicellasteridae. A family Pedicellasteridae consisting of Pedicel- lasterinae and Labidiasterinae is convenient but probably not very natural. The Pedicellasterinae comprise a series of genera which lead rather naturally to Tarsastrocles and to the Asteriinae proper whereas the affinities of the Labidiasterinae appear to be not with the Asteriinae at all, but with the Coscinasteriinae. The Coscinasteriinae and Asteriinae are two divergent lines, between which there is a distinct hiatus. SYNOPSIS OF THE GENERA OF LABIDIASTERINAE a, Abactinal skeleton reduced to isolated plates bearing slender acicular spines (with a thick dis- tally expanded sheath, bearing large crossed pedicellariae with numerous shank-teeth and enlarged lateral terminal teeth) ; alternate superomarginal plates and spines abortive; straight pedicellariae not spatulate, unguiculate; rays 12 to 20, very flexible___Rathbunaster Fisher. a. Abactinal skeleton with large squarish meshes; alternate superomarginals not suppressed. b'. Rays 9 to 11; abactinal and marginal spines acicular, prominent, solitary, rather widely spaced; skeleton of outer part of ray not reduced to transverse bands of plates carrying cushions of pedicellariae; large straight pedicellariae, when present, spatulate, a UB SUICWIAte sax Ns ER OR a ee Sea e Coronaster *! Perrier. b?. Rays upwards of 45 (25-45); marginal and abactinal spinelets not very prominent nor widely spaced; more or less aggregated in transverse bands; skeleton of outer part of ray reduced more or less to transverse arches carrying cushions of pedicellariae; straight pedicellariae notlarge;-unguiculates-- 8 se Labidiaster ** Liitken. Genus RATHBUNASTER Fisher Rathbunaster Fisumr, Proc. Wash. Acad. Sci., vol. 8, Aug. 14, 1906, p. 136. Type, R. cali- fornicus Fisher; Bull. U. 8. Nat. Mus. 100, vol. 3, 1919, p. 493; Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 249. Diagnosis.—In general appearance somewhat resembling Ooronaster Perrier. Abactinal skeleton reduced to spaced circular, independent plates (without a trace of 51 Coronaster Perrier, 1885, emended Fisher. Type C. parfaiti Perrier. See Fisher, Starfishes of the Philippine Seas, 1919, p. 494. Synonyms, Stolasterias Sladen part; Heterasterias Verrill, 1914, p. 46. This genus includes C. parfaiti Perrier, Cape Verde Islands; C. antonii Perrier, Morocco; C. briareus (Verrill), off Atlantic coast of southern United States; C. octoradiatus (Studer ) South Georgia Island; C. volsellatus Sladen, Philippine Islands. GC. halicepus Fisher, Philippine and Molucca Islands; C. eclipes Fisher, Hawaiian Islands. (Sea Stars of Tropical Central Pacific, Bishop Mus. Bull. No. 27, 1925, p. 86, fig. 9a). % Labidiaster Liitken, 1871. Type L. radiosus Liitken. Synonym Labidiastrella Verrill, 1914, p. 352. This genus includes L. radiosus Liitken, southern end of South America, south to 64° 48” S.; L. annulatus Sladen, South Pacific north to Aru Islands; L. crassus Koehler, Antarctic. = ee i eo al tn Rll hia ees Se? M Mary ae ee aps Sees Acs ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 89 connecting ossicles) bearing, along with the marginals, a slender acicular spine incased in a retractile, distally expanded sheath beset with a terminal wreath of very numerous crossed pedicellariae; inferomarginal plates spaced; superomarginal plates just above inferomarginals and connected with them, but alternate superomarginals abortive except at very base of ray; ambulacral plates not so crowded as in Asteriinae, and about the same as in Coronaster, the ambulacral pores, in fully grown specimens, being in two slightly zigzag series, except at ends of the ray where the line is straight; tube-feet in four ranks except at base of ray (two ranked in young specimens); adam- bulacral plates short and crowded as in Coronaster, monacanthid; oral plates of Pedicellaster type, but more compressed; interbrachial septa small, entirely mem- branous; no Polian vesicles; ampullae single; tube-feet long, with sucking disks; gonads two to each ray, attached at the side about on a level with the superomarginal plates; intestinal coecum entire; crossed pedicellariae with two enlarged terminal teeth to each jaw; straight pedicellariae not unguiculate nor broadened terminally; disk circular, rays rather deciduous, 12 to 20, but undoubtedly fewer in very young specimens; body wall thin; papulae in groups of 2 or 3 to 15, rather long and vermiform, numerous, arranged on ray in poorly marked longitudinal series; two or three to five papulae spring from a single pore. Remarks.—This well-marked genus, which was named for the late Dr. Richard Rathbun, I compared originally with Pycnopodia Stimpson, to which it bears a resemblance entirely superficial. Rathbunaster seems to be more closely related to Coronaster than to any other known genus; and next to Coronaster, Labidiaster Liitken appears to be its nearest relative. Both Ooronaster and Labidiaster have a wide meshed reticulate skeleton made up of slender, lobed, cruciform plates, arranged in longitudinal and transverse series, and either joined directly by their lobes, or by one or two slender, imbricating inter- mediate ossicles. The papular areas are very large and usually fairly regularly quadrate except dorsolaterally on the basal portion of the ray where the more or less irregular dorsolateral (or adradial) series of plates introduces some irregularity. In neither genera are there actinal plates. The dorsal and lateral walls of the ray are composed of the two series of marginals, the adradials (proximally only) and the carinals. In both genera, but particularly in Coronaster, we have the characteristic sheathed and wreathed acicular spines. In both genera the abactinal skeleton, and to a certain extent the marginal connecting ossicles tend to disappear on the outer part of the ray. In Rathbunaster the abactinal and marginal connectives, a part of the abactinal primary plates and about half of the superomarginal plates have disappeared. RATHBUNASTER CALIFORNICUS Fisher Plate 12, figs. 5, 6; Plates 39, 40, 41 Rathbunaster californicus Fisumr, Proc. Wash. Acad. Sci., vol. 8, Aug. 14, 1906, p. 187; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 493.—VerriLL, Shallow-water Starfishes, 1914, p. 197. Diagnosis.—Rays usually 17 (varying from 12 to 20). R155 mm. (variable), r23 mm.; R=6.7 r (variable); breadth of ray at base, 9 to 11 mm. Disk nearly flat, circular; rays long, slender, more or less constricted at base, adjacent to disk, and somewhat inflated proximally; abactinal integument thin, membranous; abactinal 90 BULLETIN 76, UNITED STATES NATIONAL MUSEUM skeleton reduced to small circular plates widely spaced on rays but closer on disk, each bearing a slender needlelike spine heavily wreathed by pedicellariae borne on the expanded top of a retractile sheath; inferomarginal plates spaced, with a single wreathed spine; superomarginal plates and spine above alternate inferomarginals; one ratherlong adambulacral spine; papulae numerous, slender, vermiform, in groups of 2 or 3 to 15, arranged in an intermarginal series, and in four to six, sometimes evident, abactinal series; without arrangement and crowded on disk. Description —Abactinal surface of disk typically covered with very delicate needlelike spines from 2 to 2.5 mm. long, encircled by a conspicuous globose bouquet of small crossed pedicellariae borne upon a heavy sheath. This sheath consists of a circular expansion of membrane, the upper or distal convex surface of which is thickly beset with pedicellariae, while that encircling the spinelet below is naked. These wreaths are a little larger and a little more crowded inside the middle of r, although there is more or less variation. The spines spring from small roundish independent plates imbedded in the integument and spaced about 0.5 to 2 mm. apart, each plate being 0.5 to 1.25 mm. in diameter. They are a trifle convex in the center, and are closer together on the central portion of the disk than near the periphery. On the ray the plates are spaced 1 to 4 mm. apart, and about four irregular longiseries are sometimes evident, although often no serial arrangement is observable. The abactinal plates of the ray also bear each a delicate wreathed spine. These are not nearly so numerous to the square centimeter as on the disk. Scattered between the primary plates are relatively few minute grains. Marginal spines longer and stouter than the abactinal, with larger bouquets of pedicellariae. The inferomarginal plates are much larger than the abactinal plates, rudely lozenge-form and attached to the outer face of the adambulacrals, usually one to every four or five adambulacral plates. The inferomarginals are spaced in such a manner that proximally two or three adambulacrals (distally two) can be seen between them. ‘The spine is borne on a ventral boss of the plate, and is about 3.5 mm. long in large specimens. Just above each alternate inferomarginal is a somewhat larger oblong supero- marginal, the lower end of which overlaps the upper end or side of the inferomarginal, while at the dorsal end upon a boss is borne an acicular wreathed spine subequal to the inferomarginal spine, and standing directly above it. Opposite the other, alternating, inferomarginals, the superomarginals are small and rudimentary, reduced to an ossicle devoid of a spinelet, and wholly invisible until the skin is dried. This plate disappears entirely beyond the middle of R. The first five or six inferomarginals are a little more crowded and each has a spiniform superomarginal adjacent to it. The papulae are numerous, long, and vermiform, and are clustered in groups of from 2 or 3 to 10 or 15. ‘There are usually about three, but up to five, and occasion- ally more, papulae to each pore which pierces the integument. For instance, in a group of 15 papulae the coelomic surface of the body wall shows 5 pores, evenly scattered. On the disk, the long papulae are packed in tightly between the spines and their globes of pedicellariae. On the rays the papulae are really in longitudinal series but it is difficult to make them out in most specimens, except in the case of the intermarginal series. There seem to be about six abactinal series indicated. In a ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 91 specimen from station 3350 two series on either of the radial series of plates is clearly shown. The outer of these two seems to split into two less well defined lines. The adambulacral plates are very short—much broader than long, and are oriented somewhat obliquely. The intervals between the plates are longer than the plates themselves. On the furrow margin, on a slight boss, is a single spinule about 3 to 3.5 mm. long, gently tapering, and much slenderer than the inferomarginal. Farther along the ray this spinule shortens more rapidly than does the inferomarginal spine. Mouth plates small and those of the pair sometimes unequal in length, in such wise that the succeeding adambulacrals, which are joined along the interradial line with their neighbors, alternate with them instead of exactly corresponding. (See pl. 39, fig. 3a.) In form the plates are somewhat like those of the Brisingidae but much compressed. Usually there are two (sometimes three) actinostomial spinelets subequal to the foregoing, although only one suboral spine may be present, as in Plate 39, Figure 3. Pedicellariae of two kinds, crossed and straight. The crossed pedicellariae (about 0.35 mm. long) are present on the retractile sheaths of the abactinal and margi- nal spines, never on the plates themselves, nor on the adambulacral spines or plates. (Pl. 39, fig. 4a.) The straight pedicellariae (pl. 39, fig. 4) are found sparingly on the oral plates and on the base of the oral spines; on the first few adambulacral plates, especially on the furrow face; occasionally on the marginal plates; very sparsely between the abactinal plates of the base of ray and of the disk. In specimens from ‘station 3186, 3205, 3349, and 3350, from more northern localities than the type, the straight pedicellariae are much more numerous, especially on the furrow face of the adambulacral plates. These pedicellariae have a short peduncle and sometimes occur one on each of several consecutive plates, on alternate plates, or irregularly, especially toward the end of ray. They are more numerous also on the abactinal surface. The ambulacral furrow is wide and shallow, and the ambulacral plates are much less crowded than in the Asteriidae. The ambulacral pores between the plates are arranged, in large fully grown rays, in two slightly zigzag series. The tube-feet, however, owing to their posture due to crowding, appear to form four series, except in the narrowed proximal portion of the furrow. The actinostome is very wide, 24 mm. on a disk of 44 mm. diameter. Madreporic body small, circular, with radial striations, and situated one to two times its own diameter from interradial angle. Color in life: General tint of disk and rays bittersweet pink (principally the large bouquets of papulae); skin whitish mottled and crossed by fine lines of orange scarlet (grenadine red). These lines run down sides of arms and disappear between the inferomarginal spines. Actinal surface cream color, darkest near actinostome, lighter on rays. Variations.—The smallest specimen available has 12 rays, 2 of which are decid- edly shorter than the others. In the case of the longest ray, R=65 mm. while r=7mm. This specimen does not materially differ from the large ones except that the ambulacral pores form two straight series and the tube-feet are in two series. There are fewer pedicellariae on the wreaths. 92 BULLETIN 76, UNITED STATES NATIONAL MUSEUM The specimen, which is labeled as from station 3350, 75 fathoms, differs from the typical form in having 20 rays, usually 2 inferomarginal spines, numerous adambula- eral straight pedicellariae, rather more numerous abactinal straight pedicellariae, and less numerous abactinal disk spines. The specimen from station 3349, 239 fath- oms, has two inferomarginal spines on a few of the plates, but has fewer adambulacral pedicellariae (possibly scraped off some of the rays, as they are numerous on others). Both specimens have lost through abrasion a number of thin abactinal spines. These two examples seem to represent an incipient northern race. Ido not feel sure of the correctness of the label on the specimen from station 3350. It resembles so closely in color and texture, as well as in certain individual peculiarities that from the preceding station, that I believe there is a possibility of mistake. Seventy-five fathoms is abnormally shallow for this species. The same reasonable doubt attaches to the record from station 4340. Anatomical notes—The coelom of the disk is almost entirely occupied by the large eversible stomach the lobes of which, very much wrinkled, reach to the base of the rays. When the stomach is entirely withdrawn and in normal position, the dorsal division, into which the hepatic coeca empty, can be clearly differentiated. Its periphery is about 0.4 the distance from the center to edge of disk. There is a well-marked constriction between. this dorsal division and the ventral eversible stomach. The hepatic coeca depart from the dorsal stomach as a single wide duct, attached to the wall of the ventral stomach by a net-like mesentery. After passing through the constricted entrance to the radial coelom, the duct divides in two and extends about 0.8 the length of ray. Each duct is differentiated into numerous lateral unequal lobulate saccules arranged pinnately with reference to the central tube, which is fastened to the dorsolateral wall by a thin mesentery. Dorsal to the upper stomach is an intestinal coecum, rather acutely elliptical in form, about 10 mm. long and 4 or 5 mm. in diameter. It has a delicately plicated interior, and at the inner end has a conspicuous opening into the dorsal stomach and a small aperture leading into a very insignificant intestine. The interbrachial septum is a tough membrane of small size. The inner free edge reaches mesad nearly as far as the inner border of the actinostomial ring, while the outer interbrachial edge, which is fused with the wall of the disk at the inter- brachial angle, is opposite the eighth ambulacral plate. There is no rudiment what- ever of a horizontal shelf projecting from the inner border of the actinostome above the first ambulacral plates and then distad into the ray, as in the case of Heliaster. (Such a shelf forms a coelomic cul-de-sac just above the ambulacral ridge and ventral to the hepatic coeca, and is an anatomical peculiarity of Heliaster.) The gonads open upon the side of the ray about 1.5 r from the interbrachial angle, and slightly above the level of the superomarginal plates. One lobulate branch extends distad 60 mm. and another toward the base of ray about 10 or 12 mm. The short lobes of the branches are subdivided into small secondary lobes or divisions. Ampullae large, single. They form two series along each side of the ambulacral ridge, but the pores between the ambulacral plates form a single series, fairly straight in small specimens and slightly zigzag in large ones. No Polian vesicles. Type.—Cat. No. 21934, U.S.N.M. Type-locality.—Station 2925, off San Diego, Calif.; 339 fathoms, mud; bottom temperature, 42.9° F. a ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 93 Distribution —Off California, from vicinity of San Diego to Point Arena, and from 207 to 369 fathoms, mud; temperature range, 41.3° to 44.1° F.; two records from under 100 fathoms open to doubt. Specimens examined.—One hundred and fifty-one. Specimens of Rathbunaster californicus examined : B a Num- Gta: Locality Depth Nature of bottom ence her of Collection ature re | 2892 | Santa Barbara Channel, Calif_._-.-_.-.---.---- 284 44.1 46 | U.S.N.M. 2g25"|} Off San (Diego, Calif. s=—= oot oe 339 42.9 15 Do. 29271 |22 == (GU )S8 hee ee a 313 43.3 2 Do. 3186 | Off Point Sur, central California 4 328 | Black sand; mud 41.3 28 Do. 3199 | Santa Barbara Channel-_-_-__--_-- 4 233 | Green mud---..-...-- 43.9 9 Do. 3205 | Off Monterey Bay------_- e 240 | Black sand; rocks___-__ 43.7 1 Do. 3349 | Off Point Arena, Calif--_....-.-.-------------- 239 | Black sand___._._____-! 44.1 1! Do. 3350 |----- Geena eee - 75 | Fine sand; mud_-_---- 48.4 1 Do. 4339 | Off San Diego Calif-..------------------------- 287-369 | Green mud-_--_-_------- 41.5 9 | Albatross, 1904. 4340 | Off Los Coronados Islands, vicinity San Diego, 46-87 | Fine gray sand, black |__---.-- 2 | Do. Calif. specks. | 4341 |_..-. CL Oe ae Se net ea Se eh ee aia 266-323 | Gray sand, black 42. 2 Do. specks. 4363'| Off San Diego, Calif_-----.-------2..---------- 207-348 | Green mud; fine sand_| 42.8 25 | Do. Of Sprite! Cruz, Oalifs— oe. 0% - 9 see ee about 300 | Mud and shale________|_------- 10 | Stanford coll., E. F. Ricketts from cod fishermen. Remarks.—Several live specimens captured in about 300 fathoms off Santa Cruz and presented to the Hopkins Marine Station by Mr. E. F. Ricketts were kept in an aquarium for a week in water about 12 degrees higher than the 42 or 43 degrees Fahrenheit to which they were accustomed at their normal depth. These specimens were kept in subdued light and were fairly active. Small crabs and shrimps allowed to fall on the abactinal surface were instantly seized and held by the numerous batter- ies of crossed pedicellariae of the spine sheaths. In some cases the prey was then seized by the tube-feet and carried rapidly to the mouth. In others the victims suc- ceeded in escaping. Doubtless in normal circumstances this species reacts as quickly and vigorously as Pycnopodia. The absence of a connected abactinal skeleton con- fers a high degree of flexibility to the rays. In the case of polybrachiate species this is also correlated with great speed for the class. Subfamily CoscrnasreriNar Fisher Coscinasteriinae Fisumr, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1928, p. 249. The carinal, the conspicuous marginal, and the actinal plates arranged in regular longiseries; carinals, dorsolaterals (sometimes also in regular longiseries), and supero- marginals may carry a single, stout or slender, smooth or fluted, sharp or blunt, prominent, spikelike spine (sporadically two or three), provided with a collar of crossed pedicellariae; inferomarginals regularly with two prominent spines (sporadi- cally three); one series of actinal plates (in one case rudimentary); adambulacral spines one or two, always without attached pedicellariae, but these may occur on oral spines; gonads open dorsally; some genera fissiparous; never paedophorie. 64406—28——7 94 BULLETIN 76, UNITED STATES NATIONAL MUSEUM KEY TO THE KNOWN GENERA OF COSCINASTERUNAE a'. Only the outer of the two inferomarginal spines carries a cluster of crossed pedicellariae. bi, Adambulacral plates with two spines, at least on proximal half of ray; as a rule only two, or equivalent of two, series of dorsolateral papular areas (by no means always regular) on either side of carinal plates (alternate superomarginals usually spineless). cl. Rays regularly only five in adults, but six in fissiparous young of some forms; odontophore with single articulation pit on outer margin. (PI. 43, fig. 2.) d', Large spatulate, denticulate, straight pedicellariae; outer inferomarginal spines without trace of a ventrolateral web; rays semicircular or heptagonal in section; dorsal skeleton very irregular, the skeletal meshes not in two regular series on either side of the carinal line of plates; dorsolateral spines developed in even tiny specimens; they are numerous, in one or two irregular series on each side; adambulacral plates, diplacanthid proximally, monacanthid distally. Type, Asterias sertulifera Xantus. be oT en Se ae pues eae 2S ie ee eee Astrometis Fisher. d, Straight pedicellariae slender, lanceolate; outer inferomarginal spines connected in longi- series by a continuous more or less fibrous web confined to base of spines, much retracted in some dried specimens; rays pentagonal in section; dorsolateral skele- ton regular, with two series of skeletal meshes on either side of the prominent cari- nal ridge; dorsolateral spines usually late in developing and in only one series; adambulacral plates with two spines throughout; the very young are fissiparous, usually six-rayed, possibly reproducing regularly by fission. Type, Sclerasterias gquennet Perrier: ts Le a ee ee ee ee Sclerasterias Perrier. ce’, Rays seven to nine; so far as known not fissiparous; odontophore with 2 pits on outer margin (pl. 43, fig. 1); in general appearance similar to Sclerasterias but ray less markedly pentagonal in section; a well-developed series of dorsolateral and actinal spines; inferomargiual web absent or very rudimentary; only alternate superomar- ginals spiniferous, the plates generally with a conspicuous beaded area (present also in Sclerasterias and Astrometis); mouth angle rather narrow, with three to five contiguous pairs of postoral adambulacral plates; straight pedicellariae medium to large, smooth or denticulate. Type, Margaraster scaber Hutton__-__Astrostole Fisher. b?. Adambulacral plates monacanthid throughout ray. c'. One series of spiniferous actinal plates; large straight pedicellariae with denticulate jaws. d\. Fissiparous, rays 7 to 12; skin covering skeleton not unusually thick and tough; crossed pedicellariae larger, with prominent lateral tooth to terminal lip; odontophore yariable,, hype, Cemurtcata Verrill 2 e222. ee Coscinasterias Verrill. e. Alternate carinal plates oblong-elliptical, without lateral lobes; mouth angle very constricted, with five or six contiguous pairs of adambulacral plates, behind the mouth plates; odontophore, with one or two pits, or irregular, with several. (PI. 43, HSE GD) ees eer ee ee nee eee reo caren ee ee ae Subgenus Coscinasterias. @. All carinal plates four-lobed; mouth angle broader, with two or three contiguous pairs of adambulacral plates behind mouth plates, odontophore with one articulation pit on outer border; first ambulacrals broader. (Pl. 43, figs. 4, 4a.) Type, Asterias tenuisming Lamarck === ase ai ee ete ete Subgenus Stolasterias Sladen. @. Not fissiparous, rays five to seven; skeleton obscured by a thick tough skin; crossed pedicellariae very small, round tipped, without enlarged lateral terminal tooth; odontophore with two pits on outer margin. (Pl. 43, fig. 7.) One series of spinif- erous actinal plates; dorsolateral skeleton irregularly reticulated, the papular areas equivalent to three or four longiseries, but only the lateralmost in a regular series; abundant, large, broadly lanceolate, straight pedicellariae, with rather compressed denticulate jaws. Type, Asterias gelatinosa Meyen____________ Meyenaster Verrill. c’. One series of small, spineless actinal plates hidden by skin. Not fissiparous; rays five; dorsolateral skeleton normally fairly regular, the papular areas in two longiseries on either side of the carinal series; dorsolateral and carinal spines either regular or very irregular (africana); straight pedicellariae lanceolate, compressed. Type, Marthaster- vas foliacea Jullien= Asterias glacialis Linnaeus-_______________ Marthasterias Jullien. ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 95 a?, The inner as well as outer inferomarginal spine carries a cluster of crossed pedicellariae; adam- bulacral plates with two spines. b!. Secondary oblong ossicles between consecutive plates of both carinal and superomarginal series; crossed pedicellariae characteristically large, double-fanged. All primary plates spiniferous; one or two series of four or five-lobed dorsolateral plates in quincunx and connected by one of more slender ossicles, forming a very open-meshed skeleton with large, triangular, and lozenge-shaped papular areas; a few relatively huge, unguiculate, straight pedicellariae; actinal plates rudimentary, spineless; adambulacral spines two, mouth angle stout, with two pairs of contiguous postoral adambulacral plates; not fissiparous. Type, Asterias forreri de Loriol______________________ Stylasterias Verrill. b?. Carinals and superomarginals directly imbricated in series, without interpolated secondary oblong ossicles; three (or the equivalent of three) or more dorsolateral series (often very irregular) of papular areas on either side of the carinal plates. c!. Actinal spines absent, or, if present, are devoid of attached pedicellariae; adoral carina not especially long or narrow, nor actinostome sunken (two or three pairs of contiguous postoral adambulacral plates). d'. A definite series of spineless actinal plates, hidden under a thick integument; each carinal and superomarginal plate regularly spiniferous. e!. Crossed pedicellariae with two enlarged terminal teeth on each jaw, conspicuously larger than the median terminal teeth; dorsolateral plates not exceptionally numerous, in two or three regular or irregular series on each side; one species with large unguiculate straight pedicellariae; odontophore with one pit on outer margin. (Pl. 43, fig. 5.) Type, Asterias (Stolasterias) stichantha Sladen Distolasterias Perrier. e?. Crossed pedicellarie without enlarged terminal teeth; predominant straight pedicel- lariae relatively very large, broadly spatulate, with long curved tines (resembling a pair of clasped hands); dorsolateral plates very numerous, small, crowded, irregu- larly arranged, but in the equivelent of four to six (or more) series on each side; spines ornately fluted; odontophore with 2 pits on outer margin. (PI. 62, fig. 1.) Type. Asterias nanimensis. Verrill.:.--------+------_--+ Lethasterias Fisher. d?, A conspicuous series of actinal spines (without a cluster of attached crossed pedicel- lariae); crossed pedicellariae very small, without any of the terminal teeth enlarged; all straight pedicellariae slender, lanceolate; two pairs of contiguous postoral adambu- lacral plates; each carinal and superomarginal not regularly spiniferous, usually only the alternate plates; dorsolateral spines few, scattered. Type, Coscinasterias dubia Clarks(Australiq @asmania): 22s a = Bes ee Australiaster Fisher ce. A definite series of well-developed actinal spines, each with a conspicuous cluster of crossed pedicellariae on its outer side; crossed pedicellariae without two terminal teeth, larger than the other teeth; straight pedicellariae large, broadly lanceolate, compressed, to spatulate denticulate or unguiculate; oral carina narrow, with upward of five con- tiguous pairs of postoral adambulacral plates, actinostome sunken. Type, Asterias koehleri de Loriol (O. columbiana Verrill)_--------------------- Orthasterias Verrill. Remarks.—Very poor results have followed attempts to squeeze the known species of Coscinasteriinae into a few genera. In the foregoing key the analysis of the subfamily has been allowed to proceed as far as the facts seem to warrant. A number of monotypic groups has resulted but the divisions are more natural than any which have heretofore been recognized. The form of the crossed pedicellariae and their distribution on the marginal and actinal spines have been given considerable weight. They have shown themselves to be conservative and reliable characters by the simple process of testing results by other structural features. I have introduced tentatively the odontophore and the actinostomial ring. Only more observation will determine whether the pits in the outer margin of the odontophore are constant and reliable generic characters. The double pits of Astrostole, Meyenaster, and Lethasterias appear to be reliable, but too 96 BULLETIN 76, UNITED STATES NATIONAL MUSEUM much dependance should not be placed upon this criterion. In Coscinasterias calamaria the odontophores are often irregular. Sometimes there are two widely separated pits which are the articulation points of two plates, or there is only one pit with the faint imprint of others. In all probability species which usually have two pits will vary to one by the simple coalescence of the two. An arrangement of the genera in columns in order to suggest relationships is given below. Those in acolumn are believed to be rather more nearly related than are two genera in different columns. According to this scheme Stylasterias and Dis- tolasterias are very far from Orthasterias. However Stylasterias and Dvistolasterias are not so closely related as Sclerasterias and Marthasterias. Stylasterias. Sclerasterias. Meyenaster. Australiaster. Orthasterias. Marthasterias. Astrometis. Distolasterias. Coscinasterias. Lethasterias. Astrostole. Genus STYLASTERIAS Verrill, emended Stylasterias VpRRILL, Shallow-water Starfishes, etc., 1914, subgenus, pp. 48, 65, 179; genus p. 50.—Type Asterias forreri de Loriol—FisHrr, Ann. Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 256. Diagnosis —Coscinasteriinae having the inner as well as the outer inferomarginal spine armed with a pad of pedicellariae; secondary oblong ossicles between consec- utive carinal and superomarginal plates; rudimentary, spineless actinal plates; unusually large crossed pedicellariae, having two conspicuous terminal teeth on each jaw; diplacanthid adambulacrals. All primary plates spiniferous; one or two series of four or five lobed dorsolateral plates forming triangular and lozenge-shaped skeletal meshes by means of connecting slender ossicles; mouth-angle stout, with two pairs of contiguous postoral adambulacral plates; marginal plates without trace of a special- ized area of hyaline beads; ambulacral ossicles not severely compressed; straight pedicellariae large, wedge-shaped, with several curved interlocking teeth; not fis- siparous. Remarks.—The crossed pedicellariae alone will serve to identify this genus which appears to occupy a rather isolated position. It approaches Distolasterias more nearly than any other group but differs in respect to the secondary carinals and supero- marginals, and in having much larger crossed pedicellariae. Basically the design of these is similar in the two genera but the characteristics are greatly exaggerated in Stylasterias. All species of Stylasterias described since 1914 belong to other genera. STYLASTERIAS FORRERI (de Loriol) Plate 44; Plate 45; Plate 46; Plate 47, Figures 1-3; Plates 48-50; Plate 51, Figure 1; Plate 53, Figure 5 Asterias forreri px Lorton, Notes pour servir 4 l’étude des Echinodermes II, Recueil zoolo- gique Suisse, vol. 4, No. 3, 1887, p. 401, pl. 18, figs. 1, la-g; not Jennings, 1907. Asterias (Urasterias) forcipulata Verrmu, Amer. Journ. Sci., vol. 28, 1909, p. 67; Amer. Nat., vol. 43, 1909, p. 542. Orthasterias forreri Vurrtut, Shallow-water Starfishes, etc., 1914, p. 179, pl. 65, fig. 1; pl. 66, fig. 1, 2; pl. 70, fig. 7; pl. 77, figs. 1-1d; pl. 80, figs. 1-1e. a ie he ee ota” Rt a alli lls Bras a an i Sn etl i et eg Se ee ee ee ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 97 S [tylasterias] forreri Verritt, Shallow-water Starfishes, etc., 1914, pp. 48, 50. Orthasterias forreri forcipulata Verriii, Shallow-water Starfishes, ete., 1914, p. 180, pl. 62, figs. 2; 3; pl. 70, fig. 9; pl. 88, figs. 6, 6a (6a is an error, since the crossed pedicellariae are not those figured in the photograph of the type, nor do they belong in this genus).— Fisuer, Ann. Mag. Nat. Hist. ser. 9, vol. 12, 1923, p. 257 (forreri). Orthasterias leptolena Vertu, Shallow-water Starfishes, etc., 1914, p. 182, pl. 64, fig. 1, la, 2, 2a; pl. 77, fig. 2, a-d—Fisuer, Ann. Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 257 (forreri). Diagnosis—Rays five, long, slender, subterete, more or less deciduous; disk very small; dorsal spines slender, tapered, smooth; in three to five longiseries proxi- mally, three distally; heavily wreathed by basal cushions of the large crossed pedi- cellariae; each primary marginal spiniferous; inferomarginals grooved and truncate distally, each with a prominent tuft of pedicellariae; inner adambulacral shorter and slenderer than outer which has often a truncate grooved tip; large wedge-shaped straight pedicellariae with two to five teeth scattered between spines, dorsally laterally and sparingly on actinal channels. R (in fully developed specimen) 185 mm.; r 15 mm., R=13.3 r; breadth of ray at base, 19 mm. R varies to 16 r. Description—The long, slender, spikelike, evenly tapered, bluntly pointed abactinal spines are rather uniformly spaced about their own length apart or more, depending upon the degree of inflation of ray. They are arranged in three fairly regular longiseries but in most specimens other than young there is a lateral series on either side beginning near base of ray and extending a variable distance toward the extremity. In very large specimens (as Port Chester, R 290 mm., pl. 44, fig. 1) these series extend about half the length of ray, and one can count five rows of spines between the two series of superomarginals of the same ray. In this large specimen the longest dorsal spines are 4 mm.; space between, 5 to 7mm. Ina large specimen from La Jolla (R 190 to 200 mm.) the longest spines are 4.5 to 5.5 mm. in length. Sn Monterey Bay examples, which may be regarded as typical, the lateralmost series is short so that over most of the ray there are but three longiseries. Superomarginal spines, one to each primary plate, are closer together than carinals (pl. 44, fig. 1) and a little longer and slenderer. Intermarginal channel slightly less in width than length of these spines. Inferomarginal spines, two to a plate in an oblique series, are about equal, or the outer a trifle the larger and a little longer than adjacent superomarginal spine. The tips are slightly expanded, truncate, and typically gouge-shaped, the channel ex- tending sometimes a third or half way to the base. Each spine carries a thick cush- ion of crossed pedicellariae on the outer side. Actinal interradial areas very small, often quite bare, or with one or two large straight pedicellariae. The narrow area between the inferomarginal spines and adambulacrals is crossed by fine transverse furrows (one between each pair of adambulacrals). These converge (sometimes meeting) to pass between the inferomarginal combs and on irregularly across the dorsum. This actinal area sometimes carries a few large straight pedicellariae. Beneath the skin and invisible except in cleaned specimens is a series of thin actinal plates set with edge to surface. (Pl. 53, fig. 5.) At base of ray is a second series of rudimentary plates adjacent to adambulacrals. Actinal spines never present. Opposite first 10 spiniferous inferomarginal plates (really second to eleventh) there are 34 to 38 adambulacral plates; 34 or 35 in fairly large Monterey Bay exam- ples; 38 in specimen from Port Chester, Alaska. Each plate carries two very slender, 98 BULLETIN 76, UNITED STATES NATIONAL MUSEUM flattened truncate spines in an oblique series, the outer the heavier and longer. Its extremity is shallowly grooved and sometimes slightly broadened, as on the proximal part of ray. The inner spine is attached lower on the furrow face of the plate, is abruptly tapered at base, thence is very slender; not expanded nor sulcate distally. Outer spine, 6 mm.; inner, 5.5 mm. Mouth angle broad, not at all sunken, with two postoral pairs of adambulacral plates in contact interradially. (Pl. 45, fig. 7.) In young specimens (pl. 44, fig. 4) only the inner half of the first pair is in contact. The first adambulacral carries one spine, the second, either one or two. Mouth plates with usually two, rarely three, marginal spines and one long, slender, suboral spine. (PI. 45, figs. 6, 7.) Skeletal meshes large dorsally, but papulae are in small, spaced groups of from 3 to 10 papulae, there being from 2 to 6 of these groups in each mesh of the abactinal skeleton. Intermarginal papulae in a single group of from 8 to 10 to a skeletal interval, while actinally there are as many as 10 papulae proximally and only 1 or 2 distally (series extends 0.7 to 0.8 length of ray in large specimens). The thick circumspinal clusters of crossed pedicellariae in alcoholic specimens nearly touch one another and form broad cushions marking the primary skeletal plates. The pedicellariae are unusually large and are of a very characteristic form, having two relatively large terminal fangs to each jaw with a row of three or four prominent teeth below on the shank, the series ending with a group of four or five denticles where the jaws cross. In a large specimen the pedicellaria is commonly from 0.95 to 1.3 mm. long. (La Jolla; for other measurements see pl. 46.) An attentive comparison of many of these pedicellariae has not revealed variations which can be correlated with habitat. Almost the maximum variation is found in one speci- men from Kell Bay, Alaska. (pl. 46. figs. 1, la, 16.) Very young specimens have the characteristic pedicellaria, only much smaller. (Figs. 2, 2a.) Straight pedicellariae (pl. 45, figs. 1-4) are of the wedge-shaped, clawed type, generally large (figs. 1, 2, 3) but sometimes predominantly small (figs. 3a, 4) the differ- ence without apparent correlation to locality. These occur on the dorsal integument, intermarginally and sparingly on the actinal plates, especially interradially. The largest are 2.8 mm. long and are equally well developed in specimens from Alaska, Monterey Bay, and off southern California. (Fig. 3). The smaller sort (figs. 1b, 3a) occur on the same specimens with the larger. Sometimes an example will occur with only the smaller type. (Fig. 4, station 4552.) Small, broadly lanceolate, acute pedicellariae sometimes occur sparingly on the furrow margin but are more often entirely absent. Madreporic body large, circular, exposed; striae fine, radiating. Color in life from Monterey Bay examples: General tint of dorsal surface oliva- ceous sepia; spines whitish. Integument between the thick tufts of pedicellariae, deep brown, especially on disk, but little of this brown is visible on the rays on account of the masses of pedicellariae. Actinal surface, buffy white. Occasional specimens have the ground color dark bluish gray instead of brown. Variations.—These are comparatively slight considering the distribution in latitude of the species. The difference in number of large and small straight pedi- cellariae has already been mentioned. An example from station 4410 (pl. 48, fig. 1) is notable for the slender spines and long slender rays (R=16 r), yet an example from station 4421 (pl. 49, fig. 2) from i , 2 4 i ‘4 4 a x os ih 4 ie i > a 3 k. ; ae ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 99 even deeper water (229-291 fathoms) matches Monterey Bay specimens from 56 fathoms. The first specimen (4410) has numerous very large straight pedicellariae while the second has very few. No specimens from the southern part of the range are so large as the three from Naha Bay, Kell Bay, and Port Chester (pl. 51, fig. 1), although from station 4553, Monterey Bay, is a typical specimen with R 240 mm. The Kell Bay example has R 280 to290mm. The type of Verrill’s forcipulata has a ray 325mm. long. (Depar- ture Bay, 18 fathoms.) This last form is simply a giant forreri, typical in all respects. Anatomical notes.—The skeleton of the adult (pl. 44, fig. 1) if a little more regular would consist of a series of triangular meshes adjacent to carinals (point, outward) another adjacent to superomarginals (point, mesad) and separating these two, a series of quadrilateral or lozenge-shaped meshes. The actual approximation to this ideal can be observed in the figure, from which the rudimentary actinals and the adambulacrals have been omitted. Although the open dorsolateral skeleton suggests Coronaster, the resemblance is entirely superficial. Coronaster has very large, square intermarginal meshes with secondary ossicles connecting the superomarginals to inferomarginals. A characteristic feature of the skeleton is the presence of secondary supero- marginal and carinal plates between the lobed primary plates. These begin to develop in very small specimens (pl. 44, figs. 2, 3), and in fully grown examples there may be two or three between two carinals but generally only one between the superomarginals. ' The ambulacral plates are less crowded (and hence less compressed) than is usual in the Asteriidae. Thus in a space of 10 mm. at the base of ray there are 10 ambulacral plates in the large Port Chester example, while in an equally large Orth- asterias koehleri there are 14, and in Evasterias troschelii, 13. The ambulacral pores are unusually large and the outer pore series is nearer to the inner than in Orthasterias. The small actinostome is surrounded by a massive ring of plates (pl. 45, fig. 5) composed chiefly of conspicuous odontophores and the enlarged proximal end of the ambulacral ridge. In Figure 5) is shown an unusual side view of the end of the ambulacral ridge, with a single mouth plate attached, the mouth pair having been separated at the median suture. The sutural face, as well as that of the first two adambulacrals, is exposed. The odontophore abuts against the points x and xx, acting as a keystone to that arc of the circle. (Fig. 50). A dorsal process of the mouth plate (M’) also forms an essential part of the circle. The first spiniferous inferomarginal is really the second plate (pl. 44, fig. 2, 4, IT) of the series. The first plate is early shoved out of line and is under the second. In small specimens (fig. 4) it would be mistaken for an actinal. The latter are later developed between it and the adambulacrals. The small unpaired “actinal” plate shown in Figure 4 (AQ, fig. 2) forms a part of the interbrahcial septum and in old specimens sinks under the integument. It is apparently not a true actinal plate. Viscera: There is a large three-parted intestinal coecum, the thin-walled lobes of which extend into the base of three rays. Its dorsal surface is closely pressed against the dorsal wall of the disk. The dorsal stomach is fairly well differentiated from the ventral and the large hepatic coeca extend a little over two-thirds the length of the ray. The stomach proper is eversible, very spacious, and fills the small disk, its lobes extending into the rays a short distance. The gonads, undeveloped in the specimen examined, lie wholly within the ray. Each consists of a central axis and 100 BULLETIN 76, UNITED STATES NATIONAL MUSEUM numerous lobulated branches, irregularly arranged. The opening appears to be on the side of the ray, close to the interradial angle on a level with the superomarginal plates, which here bend upward. No Polian vesicles observed. Ampullae single, large, crowded. Young—Numerous young specimens taken alone and with adults, the smallest having R 9 mm., differ in appearance chiefly on account of the fewer dorsolateral spines and the relatively smaller intervals of the skeleton. The numerous connecting secondary ossicles of the adult are much fewer in number. The crossed pedicellariae are absolutely diagnostic in cases of doubt. On Plate 44, Figures 2, 3, 4, various details of the skeleton of immature examples are shown. Only a few of the secondary carinal and superomarginal ossicles are developed; the interbrachial “‘septum” or buttress has fewer plates than in the adult; only the first pair of adambulacrals meet behind the mouth plates; there are no actinal plates, the apparent first actinals being in reality the first superomarginals displaced. In examples with R less than 20 mm. ambulacral pores are in two series. A specimen with R 20 to 25 mm. is easily identified. It has three dorsal lines of spines, unequal furrow spines, bare actinal interradial areas, and characteristic pedicellariae. In young specimens both the first and second pair of adoral adambulac- rals at first have two spines each. Later the first plate loses the subambulacral and sometimes one of the second pair also loses a spine, leaving a transverse series of three for the pair. In specimens with R 50 to 100 mm. the straight dermal pedicellariae are disproportionately big, being nearly as long as the dorsal spines and considerably thicker when their “‘sheath”’ is still covering them. Orthasterias leptolena is the young phase of forreri. Type-locality —Off Santa Cruz, Monterey Bay, Calif. (de Loriol). Distribution.—Southern Alaska to San Diego, Calif.; 16 to 291 fathoms, on rocky bottom; temperature range, 43° to 51.8° F. Specimens examined.—Highty-three. Specimens of Stylasterias forreri examined Bottom) Num- Ste Locality Depth Nature of bottom fan pore Collection ature mons 2873 40; Rocks 20 ea ete 47.8 1| U.S. Nat. Mus. 2874 OT Reece Oe Sloe e enna 50.3 6 Do. 2875 40 |_---. dose22 St ae 47.8 10 Do. 2954 huis ses COs afta e ee Fqas || Sess 1 Do. 2959 55 | Green mud, gray sand, 51.9 1 Do. broken shells. Do. 3051 59 | Broken shells, rocky --.-__|__.-.___ 2 Do. 3095 42 | Rocks, broken shells _____ 47 3 Do. 3108 | Vicinity Half Moon Bay, Calif. 1 Do. 3125 | Off Santa Cruz, Calif______._______ 1 Do. 3159 | Southwest Point Reyes, Calif______ 1 Do. 8160 |____. Ose eet Soc eee oe aL eae 1 Do. 3205? | Off Monterey Bay_____-.2-_-_-.___ 240 | Black sand, rocks______.__ | 43.7 1 Do. S605;|) Monterey Bay poe 2 tue 809 2 eee Mud, sand, boulders______ aig 1 Do. Port Chester________ 1 Do. Kell Bay, Alaska. 1 | Albatross, 1903, Nana Rey? Allagica/a 2 2) i ure eee 1 Do. 232 | Naha Bay, Behm Canal, Alaska________________ 77-83 | Green mud, rocky__.----_| 43.3 1 Do. a at i —_. Ra pee a a oy ile oo ges ‘ ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS—FISHER 101 Specimens of Stylasterias forrert excamined—Continued Num- ae Locality Depth Nature of bottom acl ae Collection ture 5 mens 4410 | Off Long Point, Santa Catalina Islands, Calif___| 178-195 | Gray sand, gravel, rocks__|_-_-___- 1 | Albatross, 1904. 4421 | Off East Point San Nicholas Island, Calif.__-_- 229-291 | Gray mud, rocks__-__-_- 1 Do. 4441? | Monterey Bay, Calif. (off Point Pinos) ___ 28-35 | Black mud, sand shells- --|____-_-_ 1 | Albatross, 1904. 4535 |_.-_. GOs fae «ae Se | ees ea pea ae 54-71,| Hard gray sand. -......--=|..-.--.- 1 Do, 4550 }---_-' do_- 50-57 | Green mud, rocks__-_--__- 3 Do. 4551 |2--<- LO See ne ee ete se nee cea nee eens 56 | Coarse sand, shells rocks__|________ 8 Do. 4552) {2 2 <% NOME SESE SEER SS SEY a FB 73-66 | Green mud, rocks____---__|_______- 9 Do. AbpSH EES do-- =2.|| 74-65) Rocks-