UNITED STATES NATIONAL MUSEUM
BULLETIN 82

A MONOGRAPH
OF THE EXISTING CRINOIDS

BY

AUSTIN HOBART CLARK

VOLUME 1
THE COMATULIDS

PART 4c.— SUPERFAMILY TROPIOMETRIDA
(the families Thalassometridae and Charitometridae)

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SMITHSONIAN INSTITUTION

UNITED STATES NATIONAL MUSEUM

BULLETIN 82

A MONOGRAPH
OF THE EXISTING CRINOIDS

BY

AUSTIN HOBART CLARK

VOLUME 1
THE COMATULIDS

PART 4c.— SUPERFAMILY TROPIOMETRIDA

(the families Thalassometridae and Charitometridae)

UNITED STATES

GOVERNMENT PRINTING OFFICE
WASHINGTON : 1950

For tale by the Superintendent of Documents, U. S. Government Printing Office
Washington 25. D. C. - Price 32.25

PREFACE

Parts 3, 4, and 5 of Volume 1, Bulletin 82, include the systematic discussion of the
species and higher groups of living comatulids, or unstalked crinoids. Part 3, published
on March 21, 1931, included the account of the superfamily Comasterida. Part 4a,
published on August 5, 1941, included the account of the superfamily Mariametrida,
with the exception of the family Colobometridae. Part 4b, published on October 9,
1947, contained the account of the family Colobometridae of the superfamily Maria-
metrida, and of the families Tropiometridae, Calometridae, Ptilometridae, and Aster-
ometridae of the superfamily Tropiometrida. Part 4c, the. present one, is the concluding
section of part 4. It is a continuation of Part 4b and includes the account of the two
remaining families of the Tropiometrida, the Thalassometridae and the Charitomet-
ridae. Part 5, the concluding part of Volume 1, will be an account of the entire sub-
order Macrophreata.

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v

CONTENTS

Page

Preface iii

Order Comatulida (continued) 1

Suborder Oligophrcata (continued) 1

Superfamily Tropiometrida (continued) 1

Family Thalassometridae 1

Genus Stenometra 7

Stenometra dentata 8

Stenometra snelliusi 12

Stenometra quinquecostata 13

Stenometra diadema 18

Genus Daidalometra

Daidalomctra eurymedon 24

Daidalometra arachnoides 25

Daidalometra hana 27

Genus Stylometra 29

Stylometra spinifera 30

Genus Cosmiometra 41

Cosmiometra leilae 43

Cosmiometra delicata 46

Cosmiometra dasybrachia 47

Cosmiometra aster 49

Cosniiometra philippinensis 52

Cosmiomctra conifera 56

Cosmiometra crassicirra 58

Cosmiometra woodmasoni 60

Cosmiomctra iole 61

Cosmiometra gardineri 63

Genus Parametra 64

Parametra compressa 65

Parametra granulata 69

Parametra orion 72

Parametra lisa 83

Paramctra ajax 84

Parametra fisheri 86

Genus Lissometra 88

Lissometra alboflava 88

Genus Crotalometra 89

Crotalomctra scntifera 91

Crotalometra rustica 92

Crotalometra magnicirra 97

Genus Koehlermetia 100

Koehlermetra porrecta • 101

Koelilormetra flava 105

Genus Aglaometra

Aglaometra valida 109

Aglaometra incerta 114

Aglaometra propinqua

Aglaometra sulcata 118

VI BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Order Comatulida (continued)

Suborder Oligophreata (continued)

Superfamily Tropiometrida (continued)

Family Thalassometridae (continued) Page

Genus Stiremetra . 119

Stiremetra lusitanica 121

Stiremetra breviradia 126

Stiremetra perplexa 129

Stiremetra carinifera 130

Stiremetra acutiradia 132

Stiremetra decora 134

Stiremetra spinicirra 136

Genus Oceanometra 137

Oceanometra gigantea 139

Oceanometra magna 142

Oceanometra annandalei 144

Genus Leilametra 148

Leilametra necopinata 149

Genus Thalassometra 151

Thalassometra bispinosa 154

Thalassometra electrae 156

Thalassometra agassizii 158

Thalassometra villosa 162

Thalassometra attenuata 163

Thalassometra hirsuta 165

Thalassometra margaritifera 168

Thalassometra marginata 168

Thalassometra hawaiiensis 170

Thalassometra latipinna 171

Thalassometra gracilis 173

Thalassometra echinata 176

Thalassometra peripolos 178

Thalassometra multispina 180

Thalsasometra setosa 182

Thalassometra omissa 184

Thalassometra sp 185

Genus Horaeometra 185

Horaeometra duplex 186

Family Charitometridae 191

Genus Chondrometra 201

Chondrometra robusta 202

Chondrometra aculeata 204

Chondrometra rugosa 206

Genus Monachometra 208

Monachometra patula 209

Monachometra flexilis 213

Monachometra robusta 216

Monachometra fragilis 219

Genus Chlorometra 221

Chlorometra garrettiana 222

CONTENTS

VII

Order Comatulida (continued)

Suborder Oligophreata (continued)

Superfamily Tropiometrida (continued)
Family Thalassometridae (continued)

Genus Glyptometra

Glyptometra timorensis

Glyptometra tuberosa

Glyptometra crassa

Glyptometra inaequalis

Glyptometra septentrionalis

Glyptometra distincta

Glyptometra investigatoris

Glyptometra macilenta

Glyptometra angusticalyx

Glyptometra sparksi

Glyptometra sclateri

Glyptometra le vigata

Glyptometra lata

Glyptometra invenusta

Glyptomet ra lateralis

Glyptometra sp

Genus Crinometra

Crinometra bre vipinna

var. insculpta

var. gracilis

var. pulchella 297

OQQ

var. concmna

var. transversa

var. tuberosa

var. margaritacea

var. diadema

var. pourtalesi 309

Oil

var. laevis

var. brevipinna

var. spinosa

var. gemmata

var. coronata

var. ornata

var. granulosa

var. granulifera

var. pulchra 334

OOK

var. angusta

Genus Charitometra

Charitometra basicurva

Charit ometra incisa

Genus Poecilometra

Poecilometra acoela

Poecilometra scalaris . —

Genus Strotometra

Strotometra ornatissimus 362

QCO

Strotometra priamus

Stratometra parvipinna

Strotometra hepburniana

Index.. 371

A MONOGRAPH OF THE EXISTING CRINOIDS

By AUSTIN HOBART CLARK

Order COMATULIDA A. H. Clark (continued)

Suborder OLIGOPHREATA A. H. Clark (continued)

Super-family TROPIOMETRIDA A. H. Clark (continued)

Family THALASSOMETRIDAE A. H. Clark

Basicurva group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p.
102 (Anledon valida, A. incerta, A. gracilis, A. lusitanica, A. breviradia, A. spinicirra, A. acutiradia,
A. bispinosa, A. latipinna, A. multispina, and A. echinata; A. longicirra is referable to the Astero-
metridae, A. denticulata to the Himerometridae, A. pusilla to the Antedonidae [Perometrinae],
and the remaining species to the Charitoraetridae) ; for further references to this group see Part
4a, p. 180.

Spinifera group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 211
(Antedon quinquecoslata, A. spinifera, A. duplex, A. lusitanica, and A. compressa; A. macronema
is referable to the Ptilometridae and A. flexilis, A. patula, A. robusta, A. pourtalesi, and A. brevi-
pinna to the Charitometridae) ; Journ. Linn. Soc. (Zool.), vol. 21, 1889, p. 308 (species compared
with Antedon andersoni [= Pontiometra andersoni; Colobometridae]) . — HAETLAUB, Nova Acta
Acad. German., vol. 58, No. 1, 1891, p. 13 (diagnosis; range; 12 species), p. 75 (diagnosis; re-
marks).— BELL, Proc. Zool. Soc. London, 1894, p. 399 (description of Anledon bassell-smithi,
sp. nov. [=Comatclla stelligera]), p. 400 (descriptions of A. vicaria [=Mariamelra vicaria], A.
brevicirra [=Comasler distincla], and A. flavomaculata [= Stephanometra indica protectus], spp.
nov.), p. 401 (descriptions of A. moorei [ = Lamprometra palmala palmala] and A. fieldi [ = ?],
spp. nov.). — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 136 (structural posi-
tion).— MINCKERT, Arch. Naturg., Jahrg. 71, vol. 1, 1905, pp. 207, 225. — A. H. CLARK, Proc.
U. S. Nat. Mus., vol. 33, 1907, pp. 127, 129 (descriptions of new species); Smithsonian Misc.
Coll., vol. 50, pt. 3, 1907, pp. 343, 344 (characters differentiating this group not diagnostic),
p. 359 (part of species included in Thalassometra, gen. nov.), p. 361 (most of the species not in-
cluded in Thalassornclra are included in Charilometra, gen. nov.). — HARTLAUB, Mem. Mus.
Comp. Zool., vol. 27, No. 4, 1912, pp. 286, 309 (discussion), p. 310 (geographical distribution).

Granulifera group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p.
239 (Anledon muliispina and A. porrecta; the other species belong to the Charitometridae); for
further references sec p. 192.

Thalassometridae A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136 (includes Poecilo-
metra, Thalassomelra, and Charilometra); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 210 (in key),
p. 211 (includes Thalassometra, Slylometra, Charitometra, and Poecilomelra; range; represented
in the Hawaiian Islands), p. 212 (range of component genera); Proc. U. S. Nat. Mus., vol. 35,
1908, p. 120, fig. 19 (arm structure); Amer. Nat., vol. 42, No. 503, 1908, pp. 724, 725 (color);
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 1 (revision; division into two subfamilies; descrip-
tions of new genera) ; Proc. U. S. Nat. Mus., vol 36, 1909, p. 361 (part of Antedon of P. H. Car-
penter), p. 362 (perfected ambulacra! plating only in this family and in the Tropiometridae),
p. 365 (covering plates in two rows instead of one as in Comatilia; side and covering plates found
in the pentacrinoids) ; Proc. Biol. Soc. Washington, vol. 22, 1909, p. 174 (referred to the Coma-
843803—50 2 1

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

tulida Oligophreata); Vid. Medd. Natur. Foren. K0benhavn, 1909, p. 122 (solitary habit, cor-
related with the small, slowly developing eggs), p. 126 (characteristic of the Intermediate area),
p. 152 (cirri compared with those of Zygometra fluctuans [ — comata]) , p. 182 (radial articular faces
of Asterometra as in this family); Ann. and Mag. Nat. Hist., ser. 8, vol. 5, 1910, p. 360, fig. 2
(portion of a pinnule showing the side- and covering-plates for comparison with the "snow-shoes"
of Bonasa umbellata) ; Proc. U. S. Nat. Mus., vol. 40, 1911, p. 6 (8 species in African waters),
p. 7 (species on northwest coast), p. 8 (species on west and southeast coasts), p. 10 (West Indian
and corresponding East Indian genera), p. 649 (referred to the Oligophreata); Amer. Journ.
Sci., ser. 4, vol. 32, No. 188, Aug. 1911, p. 130 (significance of the distinctive characters of
Ptilometra) ; Die Fauna Siidwest-Australiens, vol. 3, Lief. 13, 1911, p. 438 (2 genera and 3 species
in Australia) ; Mem. Australian Mus., vol. 4, 1911, p. 717 (proportion of the species of this family
in Australia as known to P. H. Carpenter), p. 720 (proportion of the species of this family in
Australia), p. 725 (Asterometra and Pterometra absent from Australia), p. 728 (raised to family
rank from a subfamily and Ptilometra, Pterometra, and Asterometra assigned to it from the Trop-
iometridae), p. 729 (young differ widely from the adults), p. 730 (key to the Australian genera). —
HABTLATJB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 286 (constitution; discussion). —

A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 6 (number of East Indian genera; genera
found also in the Atlantic; genera represented by closely allied genera in the Atlantic; exclusively
East Indian genera; number of East Indian species), p. 10 (greatly developed in Japan), p. 11
(represented in the Ceylon region by Pterometra), p. 12 (represented in the Red Sea region by
Thalassomelra, in the southeast African region by Tkalassometra and by Cosmiomelra), p. 13
(East Indian and corresponding West Indian genera), p. 14 (characteristic of the Intermediate
fauna, but 3 species are littoral), p. 23 (distribution in detail; 0-1,600 fathoms), p. 42 (Ptilometra,
Pterometra, and Asterometra removed from the Tropiometridae to this family; raised from a
subfamily to a family), p. 59 (key to the included genera). — SPRINGER and CLARK, Zittel-
Eastman's Paleontology, 1913, p. 236 (in the Oligophreata). — A. H. CLARK, Bull. Inst. Oc6a-
nographique, Monaco, No. 294, 1914, pp. 7, 8 (temperature relations); Internat. Rev. gesamt.
Hydrobiol. Hydrogr., 1914, pp. 4 and following (Atlantic and corresponding Indo-Pacific gen-
era).— ALEXANDER, Rec. Western Australian Mus., vol. 1, pt. 3, 1914, p. 108. — A. H. CLARK, Rec.
Western Australian Mus., vol. 1, pt. 3, 1914, p. 115 (genus and species collected by the Endeavour
in Western Australia); Journ. Washington Acad. Sci., vol. 5, No. 4, 1915, pp. 126-134 (phylo-
genetical and paleontological significance of the bathymetrical range) ; Die Crinolden dor Antark-
tis, 1915, p. Ill (synonymy; diagnosis; geological, geographical, bathymetrical, and thermal
ranges), p. 132 (covering plates compared with those of Promachocrinus and related genera),
p. 164 (represented in South Africa by Crotalometra magnicirra) • Amer. Journ. Sci., vol. 40, 1915,
p. 67 (detailed philosophical discussion of the bathymetrical range); Internat. Rev. gesamt.
Hydrobiol. und Hydrographie, 1915, pp. 223 and following (detailed account of distribution
of Australian species); Smithsonian Misc. Coll., vol. 65, No. 10, 1915, pp. 43 and following
(phylogenetic study); Unstalked crinoids of the Siboga-Exped., 1918, p. 139 (key to the included
subfamilies). — MORTENSEN, Studies in the development of crinoids, 1920, p. 3 (discussion of eggs
and distribution). — A. H. CLARK, Univ. Iowa Studies in Nat. Hist., vol. 9, No. 5, 1921, p. 12
(represented in the West Indies); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, p. 3. — GISLEN,
Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, pp. 9, 99. — A. H. CLARK, The
Danish Ingolf-Exped., vol. 4, No. 5, 1923, p. 40 (Atlantic genera and species), p. 48 (in key),
p. 51 (key to the Atlantic genera). — GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, pp. 19, 30,
31, 35, 42, 79, 84, 85, 88, 90, 91, 97, 100, 166, 193, 231, 239, 280, 284; Vid. Medd. Dansk Naturh.
Foren. K0benhavn, vol. 83, 1927, p. 39. — MORTENSEN, Handbook of the echinoderms of the
British Isles, 1927, p. 15, p. 16 (in key), p. 25 (northeast Atlantic species). — GISLEN, Ark. Zool.,
vol. 19, No. 32, Feb. 20, 1928, pp. 6, 10. — BOONE, Bull. Bingham Oceanographic Collection, vol.
1, art. 4, April 1928, p. 3.— H. L. CLARK, Rec. South Australian Mus., vol. 3, No. 4, May 9, 1928,
p. 368.— A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 647.— NOBRE,
Echinodermes de Portugal. 1931, p. 159 (diagnosis), p. 163. — A. H. CLARK, Ann. Mag. Nat.
Hist., ser. 10, vol. 10, No. 58, Oct. 1932, p. 379; Rec. Indian Mus., vol. 34, pt. 4, Dec. 1932,
p. 565. — SIEVERTS, Neues Jahrb. Mineral., Geol., und. Palaontol., vol. 69, Beilage-Band, Abt.

B, 1932, p. 156, footnote. — GISLEN, Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 93,

A MONOGRAPH OF THE EXISTING CRLNOIDS 6

October 26, 1933, p. 483.— A. H. CLARK, Treuhia, vol. 14, livr. 2, December 1933, p. 213.—
GISL£N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20, 22, 23, 25,
27, 28, 43.— A. H. CLABK, Temminckia, vol. 1, 1936, p. 313; John Murray Expcd. 1933-34,
Sci. Reports, vol 4, No. 4, 1936 (Jan. 1, 1937), pp. 92, 101, 103. — GISL£N, Kungl. Svenska Vet.
Handl., ser. 3, vol. 17, No. 2, Oct. 3, 1938, pp. 4, 17. — NOBRE, Echinodermes de Portugal, 1938,
p. 185.— H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 8.— A. H.
CLABK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74.

Thalassometridae with rounded and spiny rays and arm bases A. H. CLARK, Amer. Nat., vol. 42,
No. 500, 1908, p. 542 (characteristic of Oceanic area); Geogr. Journ., vol. 32, No. 6, 1908, p. 602
(same) ; Proc. U. S. Nat. Mus., vol. 36, 1909, p. 495 (comparison of ambulacra! plating with that
of West Indian species of the Fimbriata group of Actinometra) .

Thalassometrinae A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 2 (diagnosis and com-
parisons), p. 13 (revision of included genera); Vid. Medd. Naturh. Foren. K0benhavn, 1909, p.
124 (multibrachiate condition fortuitous in most species), p. 136 (transition segment in cirri
comparable to that in Comafella slelligera), p. 151 (transition segment comparable with that of
Zygomelra fluctuant [^comala]); Mem. Australian Mus., vol. 4, 1911, p. 728 (raised to family
rank).— HARTLATJB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 286 (discussion).— A. H.
CLARK, Bull. Inst. Ocdanogr. Monaco, No. 294, 1914, pp. 7, 8 (temperature relations); Journ.
Washington Acad. Sci., vol. 4, No. 19, 1914, pp. 559-563 (correlation of geographical and bathy-
metrical ranges); No. 20, 1914, p. 582 (relation to temperature of habitat); vol. 5, No. 4, 1915,
pp. 126-134 (pnylogenetical and paleontological significance of the bathymetrical range);
Amer. Journ. Sci., vol. 40, 1915, p. 67 (detailed discussion of bathymetrical range);
Unstalked crinoids of the Siboga-Exped., 1918, p. 140 (in key; geographical and bathymetrical
ranges), p. 145 (key to the included genera); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, pp.
3, 13.— GISL£N, Zool. Bidrag Uppsala, vol. 9, 1924, pp. 85, 90.— BOONE, Bull. Biugham Ocean-
ographic Collection, vol. 1, art. 4, April 1928, p. 3. —A. H. CLARK, Journ. Linn. Soc. (Zool.),
vol. 36, No. 249, April 1929, p. 647; Ann. Mag. Nat. Hist., ser. 10, vol. 10, No. 58, October
1932, p. 379; Rec. Indian Mus., vol. 34, pt. 4, December 1932, p. 565.

Thalassometres A. H. CLARK, Bull. Mus. Hist. Nat., Paris, No. 4, 1911, p. 255 (including Plilometra,
taken from the Tropiometridae).

Thalassometriden A. H. CLARK, Die Crinoiden der Antarktis, 1915, p. 192 (species and genera of
this family especially characteristic of the Intermediate fauna).

Diagnosis. — A family of the superfamily Tropiometrida in which the ventral
perisome of the pinnules is protected by well-developed and conspicuous side- and
covering-plates easily visible with a hand lens; PI is longer and stouter than P^; and the
cirri, usually long and slender, rarely of moderate length and rather stout, are composed
of more than 25 segments of which the distal are usually much shorter than the proxi-
mal, broader than long, with prominent dorsal spines or carinate processes; a well-
marked transition segment is usually present, beyond which the segments have the
surface light in color and highly polished.

Geographical range. — From southern Japan, the western Aleutian Islands, the
Hawaiian Islands, the Galapagos Islands, and PanamA to the Kermadec Islands and
southeastern Australia (Bass Strait) westward to the east coast of Africa and the
Crozet Islands, and in the Atlantic from Tristan da Cunha and Ascension northward
to the Bay of Biscay, the Caribbean Sea, and the Bahamas.

Bathymetrical range. — From 22 to 2,925 meters.

Thermal range.— From 1.2° to 23.6° C.

Remarks. — The species of the family Thalassometridae, though diversified, are
quite distinctive, the stiff pinnules with well developed side- and covering-plates, the
enlarged PI, which is always larger and often much longer than P3, and the usually long
and slender cirri which bear dorsal spines in the outer portion, making them easy to

4 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

recognize. The species of Parametra, which have relatively short and stout cirri with
few segments, bear considerable superficial resemblance to some of the species of the
family Charitometridae, but the cirri have an exceptionally well-marked transition seg-
ment beyond which the segments are light in color with a polished surface and bear
dorsal processes, and PI, though not greatly enlarged, is longer than P2. In Leilametra
the cirri are very long and straight with numerous (up to 83) segments which do not bear
dorsal processes; but PI is long and basically enlarged as in related genera.

The 14 genera included in the family Thalassometridae fall into three distinctive
groups. In the first group, consisting of the genera Stenomctra, Daidalometra, Stylo-
metra, Cosmiometra, Parametra, and Lissometra, the arms are strongly compressed lat-
erally and are sharply carinate, at least in the outer portion, and are always, except for
individual variants in the genera Daidalometra and Parametra, more than 10 in number
with all the division series 2; PI resembles P2, but is longer and proportionately stouter.
This group ranges from southern Japan and the Bonin and Hawaiian Islands to Queens-
land and westward to Ceylon and the Maldive Islands, and is represented by the genus
Stylometra in the Caribbean Sea; it occurs in water of from 22 to 795 meters in depth.
Four of the six genera (Stenometra, Daidalometra, Parametra, and Lissometra) are con-
fined to the area between southern Japan, northern Australia, and the Sunda Islands.
Of the other two, Cosmiometra covers the entire range of the group, occurring in the
Hawaiian Islands, in Bass Strait between Australia and Tasmania, and in the Maldive
Islands, with the related Stylometra in the Caribbean Sea.

In the second group, consisting of the genera Crotalometra, Koehlermetra, Aglao-
metra, Stiremetra, Oceanometra, Leilametra, and Thalassometra, the arms are rounded
dorsally to the tip and are 10 or more in number, if more than 10 the IIBr series are
4(3+4) or both 4(3 + 4) and 2, or by occasional individual variation 2; PI is longer than
the pinnules following and is usually much stouter basally with carinate processes on
the segments; P2 may be small and short like the segments following, or it may be inter-
mediate in character between PI and PS in the larger species. This group ranges from
southern Japan, the western Aleutian and Galapagos Islands and Panama, to Fiji, the
Kennadec Islands, and southeastern Australia, and westward to east Africa from Sokotra
to the Crozet Islands; hi the Atlantic it is found from Tristan da Cunha to the Bay of
Biscay ; it occurs in water of from 55 to 2,925 meters, the usual depth being considerably
greater than in the case of the preceding group. Of the 7 genera included in this group
two, Thalassometra and Stiremetra, are found practically throughout the entire range
of the group; both are confined to very deep water; one, Crotalometra, ranges from the
East Indies to southeastern Africa, being represented in the south and east Atlantic by
the closely related Koehlermetra; one, Oceanometra, a close relative of Thalassometra,
ranges from the East Indies to the Hawaiian Islands; one, Aglaometra, bearing much
the same relation to Stiremetra that Oceanometra does to Thalassometra, ranges from the
East Indies to the Kermadec Islands; and one, Leilametra, is known only from Lombok.
But so little is known about the species of this group that any generalizations based upon
the distribution of the various genera would be premature. For instance, no species
are reported from the Caribbean Sea where some of the genera are certainly represented.

The third group, including only the genus Horaeometra, is characterized by the
abrupt expansion of the third-fifth segments of the genital pinnules, which form a

A MONOGRAPH OP THE EXISTING CRINOIDS 5

protecting roof over the gonads. The genus Horaeometra is confined to the Caribbean
Sea, occurring in water of from 159 to 479 meters in depth.

History. — In Dr. P. H. Carpenter's Challenger Report published in 1888 the species
of the family Thalassometridae known to him were distributed among the Basicurva,
Spinifera, and Granulifera groups of the genus Antedon. The family Thalassometridae
was established in 1908 to include the genera Thalassometra, Poecilometra, and Chari-
tometra, the genus Stylometra being added later in the same year. In January 1909,
the family Thalassometridae was divided into the subfamilies Thalassomctrinae, in-
cluding the genera Stylometra, Thalassometra, Stenometra, Stiremetra, Parametra, and
Cosmiometra, all but the two first new, and Charitometriuae, the equivalent of the family
Charitometridae as now understood.

In 1911 the subfamily Thalassometrinae was raised to family rank and Ptilometra,
Pterometra, and Asteromctra were transferred to it from the family Tropiometridae. In
1914 the family Thalassometridae was divided into the two subfamilies Ptilometrinae,
including the genera Ptilometra, Pterometra, and Asterometra, and Thalassometrinae,
including the remaining genera. In 1934 Prof. Torsten Gislcn raised the subfamily
Ptilometrinae to family rank, leaving the family Thalassometridae as herein understood.

KEY TO THE GENERA OF THE FAMILY THALASSOMETRIDAE

a1. Genital pinnules with no appreciable expansion of earlier segments.

61. Arms, at least in outer portion, laterally compressed and sharply carinate, the carination pro-
duced into a high crest or broad overlapping spine; arms more than 10 (or by individual
variation 10) in number, the division series all 2; PI longer and proportionately stouter than
P2, though not otherwise different.

c1. Division series and arm bases narrow and laterally compressed, gablelike in cross section like
the outer brachials, the carination of the outer brachials being continued proximally to
the centrodorsal; cirri long and slender.

dl. Arms 20 in number, 65-100 mm. long in fully developed individuals (from Timor and the
Moluccas north to the Boniu Islands and southern Japan; 141 [?95]-457 meters).

Stenometra (p. 7)

(P. Arms 10-18 (usually 10-15) in number, usually 60-65 mm. long (from Port Denison,
Queensland, to Timor and north to southern Japan; 22-548 meters).

Daidalometra (p. 23)
c1. Division series and arm bases evenly rounded or more or less flattened dorsally, occasionally

with a slightly raised middorsal line.
dl. Cirri long and slender with more than 35 segments; division series and lower brachials

usually more or less spinous, or at least bordered with fine spines; 20-30 arms.
e1. Elements of the division series and lower brachials armed with numerous prominent
spines, at least along their borders; brachials beyond the proximal each with a long,
thin, broad, and prominent curved overlapping spine (Caribbean Sea; 102-508 [?548]

meters) Stylometra (p. 29)

e2. Elements of the division series and lower brachials smooth or with bands of minute
spines along their borders; carination of the brachials not produced into overlapping
spines (from southern Japan and the Hawaiian Islands to southeastern Australia and
westward to Ceylon, the Maldivo Islands, -and Saya de Malha; 183 [?12S]-730[?740]

meters) Cosmiometra (p. 41)

d2. Cirri shorter and stouter with not more than 35 segments; division scries and lower bra-
chials smooth, or with the lateral borders roughened or coarsely granular.
e1. Cirri with at most 27 (usually 20-25) segments, short and stout; division scries and arm
bases well rounded dorsally, appearing narrow and only slightly flattened against their

6 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

neighbors; 10-20 arms (from southern Japan and the Hawaiian Islands to the Philip-
pines, Moluccas, and Kei Islands; 128-795 meters) Parametra (p. 64)

e*. Cirri with 30-34 segments, of moderate length and moderately slender; division series
and arm bases very slightly convex dorsally but with a prominent sharp median
carinate process, everywhere in close lateral apposition ; lateral portion of the distal
border of the IBri, IIBri, and first brachials forming thin rounded anterior processes
which imbricate over the bases of the ossicles following; 13-15 arms (southwestern

Japan; 188 meters) Lissometra (p. 88)

62. Arms dorsally rounded to the tips, never carinate; arms 10 or more in number, the IIBr series
when present 4(3+4) or 4(3 + 4) and 2, exceptionally by individual variation all 2; Pj
usually much enlarged, very stout and much broadened basally.

e1. Cirri recurved at the tip or in the outer portion, the distal segments always carinate dorsally,
the carination usually raised into a prominent broad dorsal spine; opposing spine always
present.
dl. Division series and arm bases smooth and without spines, though the lateral edges may be

everted and tubercular or serrate.
e1. Arms more than 15 (normally 20) in number; large and stout, with the arms 75-160 mm.

long.

/'. First syzygy following a IIBr 4(3 + 4) series between brachials 3 + 4; cirri in 10 definite
columns; cirri long and slender with more than 50 segments (from Formosa, the
Philippines, and the Malay Archipelago westward to the Maldive and Laccadive

Islands and southeastern Africa; 55-1,595 [?2,047] meters) Crotalometra (p. 89)

f1. First syzygy following a IIBr 4(3 + 4) series between brachials 2 + 3; [stouter, with
stouter and shorter cirri which have not more than 50 (30-50) segments; cirri in 15
indefinite columns (from Ascension Island to the Bay of Biscay; 768-1,420 meters).

Koehlermetra (p. 100)

e2. Arms not more than 15 (usually 10) in number.

/'. Larger and stouter; 10 arms 90-150 mm. long; cirri 45-90 mm. long with 59-70 seg-
ments; IBr series and arm bases usually broadly rounded dorsally (from the Philip-
pines to Cerarn and the Kermadec Islands; 457-1,165 [?1,264] meters).

Aglaometra (p. 107)

P. Smaller and more slender; 10-14 (but rarely more than 10) arms 45-80 mm. long; cirri
17-50 mm. long with 30-66 segments; IBr series and arm bases carinate or subcari-
nate (from the Hawaiian Islands to Fiji, the Kermadec Islands, and southeastern
Australia westward to the Laccadive Sea; from the Canary Islands to Cape Carvoeiro,

Portugal; 649 [?640]-2,468 meters) Stiremetra (p. 119)

d2. Division series and arm bases more or less thickly beset with small spines or tubercles, at

least laterally.

e1. Arms 15-28 in number 90-180 mm. long; a more or less prominent middorsal keel on one
or both the elements of the division series and first two brachials (from western Timor
and the Kei Islands to the Philippines and Hawaiian Islands; 55-786 [7872] meters).

Oceanometra (p. 137)

e1. Arms less than 15 (usually 10) in number (from southern Japan, the western Aleutian,
Hawaiian, and Galapagos Islands, Panama, and the Kermadec Islands westward to
east Africa from Sokotra to the Crozet Islands; and from Tristan da Cunha and Ascension

northward to the Canary Islands; 598-2,925 meters) Thalassometra (p. 151)

c*. Cirri nearly straight, not recurved at the tip, tapering to a fine point, without dorsal spines or
carination and without an opposing spine, about half the length of the arms; 10 arms about

180 mm. long (south of Lombok; 1,097 meters) Leilametra (p. 148)

a'. Genital pinnules with the third-fifth segments greatly expanded, forming a roof over the gonads;
small and rather delicate with 10-22 (usually 15-20) arms 40-50 mm. long and 30-50 (usually
30-40) cirrus segments (Caribbean Sea; Cuba to St. Vincent and ?Grenada; 159-479 meters).

Horaeometra (p. 185)

A MONOGRAPH OF THE EXISTING CRINOIDS 7

Genus STENOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 215, and following
authors.

Thalassomctra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.

Stenometra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (diagnosis; genotype
Antedon quinquecostata P. H. Carpenter, 1888); Vid. Medd. Naturhist. Foren. K0benhavn, 1909,
p. 193 (probably occurs at Singapore); Crinoids of the Indian Ocean, 1912, p. 9 (absent from
Australia), p. 11 (absent from the west coast of the Malay Peninsula, the Andamans, and farther
west), p. 24 (range), p. 59 (in key), p. 209 (original reference; type); Journ. Washington Acad.
Sci., vol. 6, No. 5, 1916, p. 116 (comparison of arms with those of Daidalometra); Unstalked
crinoids of the Siboga-E,xped., 1918, p. 148 (in key; range), p. 156 (key to the included species). —
GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, pp. 9, 115, 118; Ark.
Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7. — A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No.
249, April 1929, pp. 647, 649.— GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11,
1934, p. 20.

Diagnosis. — A genus of Thalassometridae in which the division series, which are
all 2, and arms are laterally compressed and sharply carinate, gablelike in cross section,
the brachial carination being produced into high crests or broad overlapping spines;
the arms in fully developed individuals are normally 20 in number, 65-100 mm. long;
there is no appreciable expansion of the earlier segments of the genital pinnules; PI
resembles P2 but is somewhat longer and proportionately stouter; the cirri are long,
slender, and delicate, 25-75 mm. long with 50-90 segments, and are arranged in 10
columns on the small conical or truncated conical centrodorsal.

Geographical range. — From Timor and the Moluccas north to the Bonin Islands
and southern Japan from the Korean Straits to Sagami Bay.

Bathymetrical range. — From 141 (?95) to 457 meters.

Thermal range.— From 11.3° to 15.9° C.

Remarks. — The genus Stenometra as herein understood includes four species. One
of these, the very spiny S. dentata from the Bonin Islands, appears to be quite distinct
from the others, although S. snelliusi from Ceram is to a certain extent intermediate
between it and the other two. Stenometra diadema is the Japanese representative of
the East Indian S. quinquecostata from which it seems always to be distinguishable
though the differences are slight.

History. — The first known species of this genus was described under the name of
Antedon quinquecostata by Dr. P. H. Carpenter in 1888. It was transferred to the new
genus Thalassometra upon its establishment in 1907. In 1909 I proposed the genus
Stenometra with Antedon quinquecostata P. H. Carpenter, 1888, as the genotype, listing
as the included species conifera Hartlaub, diadema A. H. Clark, hana A. H. Clark, and
quinquecostata P. H. Carpenter, all of which had been originally described in the genus
Antedon. Later in 1909 conifera was transferred to the genus Cosmiometra, and in 1916
hana was selected as the genotype of the new genus Daidalometra, the combination
Daidalometra hana having appeared without any explanation in 1915.

KEY TO THE SPECIES IN THE GENUS STENOMETRA

a1. Proximal and distal edges of the elements of the division series and lower brachials not swollen or
everted, and sparsely or not at all spinous or denticulate; few or no spines on the lateral portions
of the elements of the division series and arm bases; cirri slender, the longest segments at least
twice as long as broad.

8 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

61. Keels on the elements of the division series with the crest coarsely dentate, that on the IBrj
strongly bidentate (southern Japan from the Korean Straits to Sagami Bay; 141[?95]-311

meters) diadema (p. 18)

b2. Keels on the elements of the division series with the crest straight (from the Philippines to the

Moluccas and Timor; 183-457 meters) quinquecostata (p. 13)

a1. Proximal and distal edges of the elements of the division series and lower brachials everted and
denticulate or spinous; lateral portions of the elements of the division series and lower brachials
conspicuously spinous; cirri stouter, the longest segments not more than half again as long
as broad.

61. Elements of the division series and lower brachials with the proximal and distal borders everted,
very strongly produced, and lobate or coarsely spinous; brachials as far as the fifteenth or
twentieth with a supplementary prominence on each side of the median keel; lateral borders
of the elements of the division series and lower brachials with numerous long tubercles or

spines (Bonin Islands; 183-210 meters) dentata (p. 8)

6*. Elements of the division series and lower brachials with the proximal and distal borders swollen
and irregular but not produced, more or less tubercular, armed with scattered spines; no
supplementary prominences on the earlier brachials; lateral borders of the elements of the
division series and earlier brachials with a conspicuous development of short spines (north
of western Ceram; about 200 meters) snelliusi (p. 12)

STENOMETRA DENTATA Gisten

Slenometra denlala GISL£N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 115
(description; Bock's stations 55, 56, 59; notes and comparisons), figs. 87-91, p. 112, pi. 1, fig. 7;
Zool. Bidrag Uppsala, vol. 9, 1924, pp. 14, 80, figs. 107, 108, p. 87 (synarthrial faces) ; Kungl.
Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.

Diagnostic features. — The elements of the division series and first two brachials
have the proximal and distal edges everted and strongly produced, lobate or coarsely
spinous, and the lateral borders with numerous long tubercles or spines; and the
brachials as far as the fifteenth or twentieth have a supplementary prominence on
each side of the median keel. The 15-20 (usually 20) arms are 60-65 mm. long, and
the longest cirri are 25-34 mm. long with 56-76 segments.

Description. — The centrodorsal is cylindrical with the flattened dorsal pole beset
with small spines. The diameter of the dorsal surface is 2 mm., and the height of the free
part of the centrodorsal is 1.5 mm. The cirrus sockets are arranged in five radial
groups, the groups in more or less evident alternating columns, which are separated
interradially by bare strips.

The cirri are XXIV, 74-76, 25-34 mm. long. The first segment is short with
a distal collar which, especially ventrally, has a somewhat serrate edge. The second
and third segments are twice as broad as long, similar to the first but with a more
slightly developed distal collar. The fourth and fifth segments are about as long as
broad or a little longer than broad. The sixth-tenth segments are half again as long
as broad, slightly constricted centrally. The first-seventh segments have a small
ventral spine, slightly projecting in lateral view, because of the collar mentioned
above. The eighth-thirteenth (or -sixteenth) segments are smooth, those following
with a dorsal spine. The distal segments are from two to three times as broad as long.
The dorsal spines are small, distinct, distally curved, their height from one-third to
one-fourth the width of the segments. The opposing spine is somewhat stouter, its
height equal to half the width of the penultimate segment. The terminal claw is
about as long as the penultimate segment.

A MONOGRAPH OF THE EXISTING CRINOIDS 9

The radials are narrowly bandlikc, interradially somewhat bent outward by the
interradial stripes on the centrodorsal. The IBri are four times as broad as long, with
a median carination and provided both proximally and distally with a vertical 4-5-
lobed calcareous plate composed of the produced and everted ends of the ossicle. The
IBr2 (axillaries) are twice as broad as long, rhomboidal, in the proximal portion with a
well-defined strong median tooth appearing in lateral view as a high bidentatc crest
which, together with the disto-median tubercle of the IBri, forms a strong synarthrial
tubercle. The distal edge of the IBr2 is obtusely angled with 6 or 7 pointed prominences.
The IIBr series are 2, similar to the IBr series but with smaller and weaker synarthrial
tubercles.

The probably 20 arms arc 65 mm. long, indistinctly flattened laterally. The first
six brachials are smooth, but bear both proximally and distally prominent lamelli-
shaped lobate prominences similar to those on the ossicles of the division series. In
addition, the most proximal brachials are partly with a median dorsal prominence which
more distally develops into a dorsal spine, and partly with a pair of similar mediolateral
prominences alternately most developed on the left and on the right sides. These
lateral tubercles, situated on both sides of the median dorsal spine, disappear at the
fifteenth to twentieth brachials, and from this point onward only the median dorsal
spine remains. The distal brachials are rather strongly compressed laterally. About
five of the terminal brachials have rudimentary pinnules.

Syzygies occur between brachials 3+4, and 22 + 23; or between brachials 3+4,
35+36, etc., with a distal intersyzygial interval of 6-11 muscular articulations.

PI is 8 mm. long with 12 or 13 segments of which the first 5-7 are concave on the out-
side, the concavity bordered by a more or less lobate winglike prominence, and the
sixth and following are a little longer than broad, smoother, with a smaller wing and
somewhat spiny distal collars. P2 is 5.5 mm. long with 11 segments. P3 is 4.5 mm.
long with 6 segments. P4 is a little longer than P3 with 7 segments. The distal pinnules
are 5 mm. long with 12 segments of which the first and second are short and those fol-
lowing from half again to twice as long as broad, the two terminal short again. The
pinnule segments are smooth, in the proximal portion triangular in section, in the distal
rounded.

The disk is encrusted with coarse granules.

The soft parts are dark brown, the skeleton lighter brown.

Notes. — The preceding description, adapted from Gisl6n, is based upon a specimen
from Bock's station 56 with probably 20 arms, but with two of the branches from a
IBr axillary broken.

A specimen from Bock's station 56 has the cirri XX, 57-61, 20-25 mm. long;
dorsal spines are developed from the twelfth segment onward. The arms are about
20 in number, 65 mm. long. The JBr axillary is rhomboidal. After about the tenth
brachial the dorsal spine is the only remaining prominence.

Syzygies occur between brachials 3+4 and" 31 + 32; or between brachials 3+4,
6 + 7, 32 + 33, etc. The distal intersyzygial interval is 8-11 muscular articulations.

P! is 7.5 mm. long with 13 segments. P2 is 5 mm. long with 10 segments. P3 is
4 mm. long with 8 segments. P4 is 3 mm. long with 7 segments. P5 is 3.5 mm. long
with 8 segments. The distal pinnules are 6 mm. long with 11 segments.

10 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Another specimen from station 56 has the cirri XXVII, 37—56, 14—24 mm. long.
The dorsal surface of the centrodorsal is 1.5 mm. in diameter. The 20 arms are 50
mm. long. The processes on the brachials are shorter than in the specimen preceding.
A single dorsal spine is developed from the tenth brachial onward. The arms are
distinctly flattened laterally out to the fifth brachial. The distal intersyzygial inter-
val is 13-16 muscular articulations. Pt is 5.5-7.5 mm. long with 13-15 segments.
P2 is 4.5-5 mm. long with 9-11 segments. P3 is 4-5 mm. long with 8-9 segments.
The distal pinnules are 5 mm. long with 11 segments.

Another specimen from station 56 has the cirri XXI, 43-57, from 18 to about
22 mm. long; the first six cirrus segments have a real ventral spine; dorsal spines are
developed from about the tenth to twentieth segments. The 15 arms are 45 mm.
long. The median keel on the IBr axillary is somewhat lower than in the type specimen.
The brachials beyond the sixth are without lateral prominences. There are about 90
brachials, of which about five of the terminal have rudimentary pinnules. The dorsal
brachial spine is low. On the four arms on one postradial series the syzygies are as fol-
lows: (1) brachials 3 + 4, 35+36, and 56 + 57; (2) 3 + 4, 33 + 34, 44+45, and 53 + 54;
(3) 3+4, 29+30; (4) 3+4, 30+31, and 43+44. The distal intersyzygial interval
is 5-18 muscular articulations. Pt is 4 mm. long with 12 segments of which the last 8
are collar-shaped with their distal edges overlapping; a similar condition, though not
so marked, occurs on P2, P3, and P4. P2 is 3.5 mm. long with 9 segments. P3 is 3
mm. long with 9 segments. P4 is 3 mm. long with 8 segments. The distal pinnules
are 5.5 mm. long with 12 segments.

Another specimen from station 56 has the cirri XVIII, 54-65, 25-30 mm. long.
The 15 arms are 60-65 mm. long. A regenerate from a IIBri has two small, still smooth,
arms. PI is 4-6 mm. long with 8-13 segments. P2 is 4 mm. long with 8 segments,
P8 is 3 mm. long with 7 segments. The distal pinnules are 5.5 mm. long with 9-10
segments.

A specimen from station 59 has the cirri XVIII, 62-65, 24-28 mm. long. The 16
arms are broken. The IIBr series are 2. Pj is 5 mm. long with 13 segments. The
disk is 6 mm. in diameter.

In another specimen from station 59 the cirri are XVII, 53-60, 23-28 mm. long.
The arms are 15+, broken. The IIBr series are 2. PI is 6 mm. long with 13 segments.
The disk is 7 mm. in diameter.

Another specimen from station 59 has the cirri XIV, 40-43, 15-18 mm. long, in one
and a partial second row, hardly divided into groups. The dorsal surface of the
centrodorsal is 1 mm. in diameter. The 12 arms are 40 mm. long. The calcareous
lamellae on the proximal ossicles are only slightly serrate. A single dorsal spine is
developed from the eighth brachial. On a postradial series with one IIBr 2 series
the syzygies in the three arms are arranged as follows: (1) in the arm arising from the
IBr axillary, between brachials 3+4, 16+17, 23 + 24, and distally at intervals of 5
muscular articulations; (2) in the inner arm from the IIBr axillary, between brachials
3+4, 21 + 22, and distally at intervals of 7-8 muscular articulations; (3) in the outer
arm from the IIBr axillary, between brachials 3+4, 21 + 22, and distally at intervals
of 8 muscular articulations. For the animal as a whole the distal intersyzygial interval
is 5-8 muscular articulations. Pt is 4-4.3 mm. long with 10 segments. P3 is 3.5 mm.
long with 9 segments. P3 is 2.5 mm. long with 7 segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 11

A specimen from station 55 has the cirri XV, 20-21, from 3.5 to 5 mm. long; the
second segment has a small ventral spine, the third-fifth segments are twice as long as
broad and constricted centrally, and those following are shorter, from the tenth on-
ward about as long as broad or broader than long; from the sixth segment onward dorsal
spines are developed that reach about one-fourth the width of the segments in height.
The height of the opposing spine is equal to half the width of the penultimate segment.

The radials are twice as broad as long with a median crest and small distal promi-
nences which are interradially fused and produced anteriorly separating the IBri.
The IBri are half again as broad as long with a median tubercle and latcrodistal promi-
nences; the IBr2, and first and second brachials bear similar, still larger, lobate flanges.
The IBr2 (axillaries) are triangular, as long as broad, with a small cavity in the distal
angle.

The 10 arms are 13 mm. long. The first two brachials are as high as broad, and the
first syzygial pair (composed of brachials 3 + 4) is also as long as broad. From the
fifteenth brachial onward a mediodorsal spine is developed. The left arm is often a
little longer and better developed than the right, though in one case the reverse is true.

PI is 1 mm. long with 5 segments. P2 and P3, like Pb and Pc, are usually lacking.
The distal pinnules are 2 mm. long with 10 segments.

Orals are present, their length being one-fourth the radius of the disk; only the acute
angle remains, the base and the inner parts having been rcsorbed.

Remarks. — Professor Gislen wrote that in regard to the number of the cirrus seg-
ments this species is most closely related to Stenometra diadema, but it is well separated
from this species by the formation of the centrodorsal, the shortness of the cirri when
compared with the arms — the latter are at least twice as long as the cirri — and by the
large and many prominences on the ossicles of the arm bases. In this feature this
species approaches Daidalometra hana, the genus Daidalometra being properly distin-
guished from Stenometra only by a lesser number of arms. Professor Gislen considered
Stenometra dentata to a certain extent a transition form between Stenometra and Daidalo-
metra.

Localities. — Dr. Sixten Bock's Expedition to Japan, 1914, station 55; Bonin Is-
lands; eastnortheast of Chichijima; 210 meters; shells and sand; August 15, 1914
[GislSn, 1922, 1924, 1934].

Dr. Sixten Bock's Expedition to Japan, 1914, station 56; Bonin Islands; east of the
Channel; 210 meters; August 15, 1914 [Gislen, 1922, 1924, 1934] (1, U.S.N.M., E.llll).

Dr. Sixten Bock's Expedition to Japan, 1914, station 59; east-northeast of
Anojima; 183 meters; August 15, 1914 [Gisldn, 1922, 1924, 1934].

Geographical range. — Known only from the Bonin Islands.

Bathymetrical range. — From 183 to 210 meters.

History. — Stenometra dentata was described in detail in 1922 by Prof. Torsten
Gisl6n from nine specimens that had been collected by Dr. Sixten Bock in the Bonin
Islands in 1914, one at station 55, five at station 56, and three at station 59. In 1924
he discussed the arm division, synarthries, and syzygies of this species and figured the
synarthrial faces. In 1934 he listed it among the species with the Stenometra diadema
type of arm division.

12 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

STENOMETRA SNELLIUSI A. H. Clark

PLATE 1, FIGURE 1

Stenometra snelliusi A. H. CLARK, Temminckia, vol. 1, 1936, p. 295 (listed), p. 313 (description;
Snellius station 253*), pi. 8, fig. 9.

Diagnostic features. — The elements of the division series and first two brachials
have the proximal and distal borders swollen and irregular, though not especially pro-
duced, more or less tubercular or armed with scattered spines, and the lateral borders
with a conspicuous development of short spines; and there are no supplementary
dorsolateral processes on the earlier brachials. The 20 arms are 70 mm. long, and the
cirri are 35 mm. long with 68-75 segments.

Description. — The centrodorsal is a short thick column about twice as broad as
high, 3 mm. in diameter. The dorsal pole is concave and bears scattered and irregular
more or less spinous or pointed tubercles. The cirrus sockets are arranged in ten
crowded columns of two each.

The cirri are XX, 68-75, 35 mm. long. The first segment is about four times as
broad as long and those following slowly increase in length to the seventh and eighth,
which are from one-third to one-half again as long as broad. The tenth, eleventh, or
twelfth is a transition segment, and is slightly longer than broad. The segments fol-
lowing continue to decrease in length so that those in the distal third of the cirri are
very short, about two and one-half times as broad as long. On the segments following
the transition segment the median portion of the distal dorsal edge gradually becomes
more and more prominent, involving progressively more and more of the dorsal surface,
so that the very short distal segments bear each a very high carinate spine. The earlier
segments as far as the transition segment have their distal edge all around produced.
Up to about the twelfth-fifteenth the segments have the middle of the ventral distal
edge produced into a more or less conspicuous tooth. The cirri taper from the base to
about the seventh segment, then much more slowly, and again more rapidly at the tip.

The radials are concealed in the median line, but are visible as broad low triangles
in the interradial angles. Their edges are swollen and produced, and are irregular,
more or less tubercular, and armed with scattered spines. The IBri are about five times
as broad as long, with the edges all around produced, and the distal and lateral edges
sparsely spinous. The IBr2 (axillaries) are rhombic, twice as broad as long, with the
edges everted and sharply, coarsely, and very irregularly serrate, except near the mid-
radial line, and the lateral angles very deeply and sharply serrate or spinous. The
elements of the IBr series bear very high thin median keels with the crest finely or
coarsely and irregularly serrate, or deeply notched. The IIBr series resemble the
IBr scries, but the proximal, distal, and inner borders of the ossicles are somewhat
less spiny or irregular, while the outer borders, on the outside of the postradial series,
bear numerous long, slender, and irregular spines. The crest of the high median
carination is usually smooth, but may be finely serrate, or even coarsely dentate.

The 20 arms are 70 mm. long. The first brachials are about three times as broad
as the median length, and are slightly longer exteriorly than interiorly. Their edges
are narrowly everted and are usually smooth, except that the outer side of the outer-
most first brachial on each postradial series is coarsely and irregularly spinous. The
second brachials are irregularly five sided. The inner side is about half as long as the
outer, and the proximal border forms an obtuse angle with the apex in the median line.

A MONOGRAPH OF THE EXISTING CRINOIDS 13

The edges are thickened, but smooth. There is a short spine at each angle. The
median keels of the first two brachials are lower than those on the preceding ossicles, and
the crest is smooth and straight. The first syzygial pair (composed of brachials 3+4)
is somewhat broader than long. The carinations on the hypozygal and epizygal are
not continuous, that on the epizygal being displaced outwardly. The next four seg-
ments are irregularly oblong, about three times as broad as the median length. Those
succeeding are very obliquely wedge-shaped, about twice as broad as the longer side,
terminally becoming less obliquely wedge-shaped and about as long as broad. The
arms are strongly compressed laterally, and the brachials are strongly carinate, the
carination being produced distally into a conspicuous curved overlapping spine.

Syzygies occur between brachials 3+4, again from between brachials 29+30 to
between brachials 47+48 (usually between brachials 35+36, or near that point), and
distally at intervals of 5-7 (usually 6) muscular articulations.

P, is 7 mm. long with 14-15 segments, moderately stout and tapering evenly to the
tip. The proximal outer side is strongly rounded. The ventral edges and the carinate
line on each segment are produced into high thin processes with a straight or more or
less convex crest. P2 resembles Pj, and is nearly as long and large. P3 is smaller and
shorter, and the pinnules following are shorter still.

The color in alcohol is light brown, with the outer two-thirds of the cirri lighter.

Comparisons. — This species resembles S. diade.ma from southern Japan, but it is
larger and stouter with stouter cirri which have somewhat stouter segments; the carinate
processes on the division series are higher and more even, and there is a considerable
and conspicuous development of spines interradially on the division series and arm
bases.

Parasite. — A small parasitic gastropoid (tMelanella, sp.) was attached to one of the
cirri (see Part 2, pp. 645-649).

Locality. — Willebrord Snellius station 253*; north of western Ceram (lat. 2°51'00"
S., long. 128°4S'00" E.) ; about 200 meters; April 28, 1930 [A. H. Clark, 1936] (1, L.M.).

History. — This species is known only from the single specimen dredged by the
Willebrord Snellius in 1930 and described in 1936.

STENOMETRA QUINQUECOSTATA (P. H. Carpenter)

PLATE 1, FIGURES 2, 3; PLATE 2, FIGURES 4, 6, 7
[See also vol. 1, pt. 1, figs. 9, p. 65, 269, p. 259, 485, p. 365; pt. 2, figs. 820-822, p. 392, pi. 2, figs. 979,

980.]
Antedon quinquecostata P. H. CARPENTER, Challenger Reports, Zool. vol. 26, pt. 60, 1888, p. 215

(description; Challenger station 192), pi. 3, fig. 6, a-d, pi. 38, figs. 1-3. — HARTLAUB, Nova Acta

Acad. German., vol. 58, No. 1, 1891, p. 77 (comparison with A. [Cosnriometra] conifera). — HAMANN,

Bronn's Klassen und Ordnungon des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — A. H.

CLARK, Crinoids of the Indian Ocean, 1912, p. 34 (identity). — HARTLAUB, Mem. Mus. Comp.

Zool., vol. 27, No. 4, 1912, p. 309 (in Spinifera group; history), fig. 8, p. 364 (centrodorsal and

radial articular faces).

Thalassometra quinqueco&tata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).
Stenometra quinquecostata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed);

Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 186 (compared with S. dorsala [diadema]);

Proc. U. S. Nat. Mus., vol. 39, 1911, p. 554 (compared with S. dorsata [diadema] and with S.

cristata); Crinoids of the Indian Ocean, 1912, p. 34 (identity), p. 209 (synonymy; locality);

Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 44 (notes on three Challenger specimens in the

British Museum); Unstalked crinoids of the Sifcoja-Exped., 1918, p. 156 (in key; range), p. 157

14 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

(references); Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 647 (Rotti Strait, 100
fathoms; notes), p. 649 (compared with S. diplax). — GisLisN, Kungl. Fysiogr. Sallsk. Hand!., new
ser., vol. 45, No. 11, 1934, p. 25.

Slenomelra cristata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 553 (description; Albatross
station 5275); Crinoids of the Indian Ocean, 1912, p. 210 (synonymy; locality); Unstalked
crinoids of the Si&oja-Exped., 1918, p. 157 (in key; range; references).

Stenometra diplax A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 635 (listed),
p. 647 (Rotti Strait, 100 fathoms; description; remarks), pi. 41, fig. 5; Proc. Biol. Soc. Washing-
ton, vol. 47, p. 10, Feb. 9, 1934 (new species discovered by The Cable).

Diagnostic features. — The elements of the division series and first two brachials
have the proximal and distal edges unmodified, the lateral borders smooth or sparsely
denticulate, and the median carination with the crest in profile straight. The 18-21
(usually 20) arms are 85-100 mm. long, and the cirri are 40-50 mm. long with 73-90
segments.

Description. — The centrodorsal is a short pentagonal column with five interradial
ridges which are very prominent at the ventral ends. The cirrus sockets are arranged
in more or less alternating double columns, three or four in each column, separated by
the interradial ridges.

The cirri are about XXXV, 80-90, up to 45 mm. long. Some of the proximal
segments are much longer than broad, but those following become shorter and laterally
compressed with a sharp dorsal keel which passes into a prominent spine on the short
middle and later segments.

The angles of the radials are just visible, being turned slightly outward above the
interradial processes of the centrodorsal. The IBri are short and sharply convex, rising
to meet a strongly carinate backward process of the widely rhombic IBr2 (axillaries) .
The IIBr and IIIBr series (when present) are 2. The elements of the division series
have sharp median crests that are continued out onto the arms. All these ossicles,
and especially those on the outer side of the postradial series, have straight lateral
edges and sharply flattened sides. On some arms this feature ceases at the second
brachial, though in others it is very visible on the first syzygial pair and even on the fifth
brachial.

The arms are usually 20 in number (in one case 21), about 100 mm. long, with 120
or more brachials. The brachials have a sharp median keel and become much com-
pressed laterally so that the later ones overlap rather sharply.

Syzygies occur between brachials 3+4, again from between brachials 21 + 22 to
between brachials 26 + 27, and distally at intervals of 5-12 (usually 6-8) muscular
articulations.

PI is moderately stout, about 10 mm. long, with 12-15 segments, most of which
are longer than broad; the first 4 or 5 are flattened on their outer side where they meet
the corresponding pinnule of adjacent arms, and their inner edges are also slightly cut
away. The following pinnules are rather shorter with more rounded segments, the two
at the base being wider than then- fellows on the lower part of the arm. Farther out,
however, this is less marked, and the pinnules are somewhat carinate, though never
especially long.

The disk is 7 mm. in diameter and is moderately plated, the arms rather more so;
the pinnule ambulacra have covering plates and partly differentiated side plates.
Sacculi are rare or altogether absent.

A MONOGRAPH OF THE EXISTING CRINOIDS 15

The color in alcohol is yellowish brown or whitish brown, with the perisome darker.

The preceding description is adapted from the original description of Carpenter.
In the British Museum I examined three of the Challenger specimens, two large ones
and one small. The cirri are proportionately larger and stouter than those of the
Japanese 8. diadema. The arms are 100 mm. long. The sides of the division series
are denticulate. The lateral portions of the proximal borders of the ossicles of the
division series are also more or less denticulate. The crest of the carination is sharp,
and nearly or quite straight; there is no pronounced denticulation.

Notes. — Three of the specimens from Menado Bay, Celebes, have the cirri 50 mm.
long with 76-79, 74-75, and 75 segments. All the 18 specimens have apparently 20
arms.

Of the three specimens from Rotti Strait one has 19 and another 21 arms, all the
division series being 2. The third specimen is curious in having eight of the nine
IIBr series 4, in two synarthrial pairs, instead of the usual 2. It was described as a
new species under the name of Stenometra diplax in the following terms: The centro-
dorsal is thick discoidal, about twice as broad at the base as high, 3 mm. in diameter
basally. The very broad dorsal pole is studded with evenly distributed rather short
and pointed papillae. The cirrus sockets are arranged in ten regular columns of two
sockets each, there being two columns in each radial area. In the interradial lines the
adjacent columns of cirrus sockets are separated by rather high ridges, in the midradial
lines by narrower, lower, and sharper ridges.

The cirri are XX, 73-76, from 40 to 50 mm. long, very slender and delicate. The
first segment is exceedingly short, and those following gradually increase in length to the
fifth, which is half again as broad as long, the sixth, which is slightly longer than broad,
and the seventh-twelfth, which are the longest, about one-third again as long as broad.
Beyond the twelfth the segments very slowly decrease in length, so that those in the
terminal third of the cirri are about twice as broad as long. Beginning somewhat before
the middle of the cirri the distal ends of the segments become slightly produced dorsally.
This production of the distal edge gradually narrows and at the same time extends
proximally so that the short distal segments bear a prominent sharp median dorsal
carination, the crest of which in profile at first rises gradually from the proximal to the
distal end of the segment, but later becomes strongly convex. The opposing spine is
conical, blunt, slightly higher than the process on the segment preceding. The terminal
claw is scarcely as long as the penultimate segment, and is stout and strongly curved.
The proximal segments are carinate ventrally, and the ventral and lateral portions of
the distal edge are produced, overlapping the bases of the segments succeeding. Tin's
feature gradually dies away as the segments become shorter. In lateral view the cirri
taper very slightly in the basal fourth and then remain of uniform width until near the
end, when they taper gradually to the tip.

The ends of the basal rays are visible as minute tubercles at the upper ends of the
interradial ridges on the centrodorsal.

The radials are extremely short, chevron-shaped, with the distal border narrowly
and the lateral edges thickly everted and irregularly dentate. The IBn are chevron-
shaped, very narrow and bandlike, from six to eight times as broad as long. The proxi-
mal edge bears a few scattered teeth or lobes or other irregularities, and the lateral
portions of the distal edge are more or less strongly dentate. The IBr2 (axillaries) are

16 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

rhombic, not quite twice as broad as long; the lateral angles are just in contact with
those of their neighbors, and the distal and proximal angles are similar, the latter
being somewhat more rounded. The proximal half of the median line carries a rather
high sharp keel with a straight crest. Of the nine IIBr series present, eight are 4, the
axillary in no case being united to the preceding ossicle by syzygy, and one is 2. The
division series are narrow and high, gablelike in end view, and the middorsal line is
occupied by a sharp and conspicuous, though not high, carination. The lateral borders
of the ossicles may be sparsely denticulate, but the proximal and distal edges are unmod-
ified. The division series are in very close apposition, and the sides of the component
elements are sharply flattened.

Only the arm bases are preserved. There were at least 19 arms. The brachials
are deep and much compressed laterally, with a low but sharp median carination, which
is obscure on the earlier brachials, though becoming conspicuous as the brachials
become triangular.

Although the occurrence of IIBr series of four elements instead of two would seem
at first sight to be an important character sharply distinguishing this form from S.
quinquecostata, it is undoubtedly only an aberrant specimen of the latter. The two
were taken together, and they seem to agree in every other feature, though the present
specimen is slightly smaller than those identified as S. quinquecostata and has somewhat
more slender cirri. This would be likely to be the case, however, with any markedly
aberrant individual. It is noteworthy that in the IIBr series the two distal elements
are never united by syzygy, which would indicate that they are not the morphological
equivalent of IIBr series of 4(3+4). These latter are not known to occur in Stenometra,
or in any of the closely related genera. The occurrence of IIBr series of four ossicles
of which the two outermost are not united by syzygy is not infrequent in comatulids
in which the division series are normally 2. I once described under the name of Cyl-
lometra anomala (see Part 4b, p. 145) a specimen of C. manca in which six of the seven
IIBr series present are of four elements.

In 1911 I described a new species, Stenometra cristata, from Albatross station 5275,
saying that it is nearest S. diadema from southern Japan, but is a smaller and more
slender form; the centrodorsal is proportionately smaller, more conical and less columnar,
with a finely papillose rounded conical tip; the cirri are about 40 mm. long; the longest
cirrus segment, the fifth or sixth, is twice as long as broad or even somewhat longer
instead of being but little longer than broad as in S. diadema; the carination of the
division series and lower brachials is not quite so high as in S. diadema, and is more
regular with a more even profile; the profile is irregular and serrate in S. diadema;
the type specimen has 20 arms 85 mm. long. Four smaller specimens with 18, 17,
14, and 13 arms, the last two being immature, were secured at the same station. I
cannot see that this supposed new species differs in any essential feature from S.
quinquecostata.

Localities. — Albatross station 5275; China Sea, in the vicinity of southern Luzon;
Malavatuan Island (N.) bearing S. 71° E., 10.75 miles distant (lat. 13°55'55" N.,
long. 120°10'15" E.); 214 meters; fine sand; July 16, 1908 [A. H. Clark, 1911, 1912,
1918] (6, U.S.N.M., 27501 [type specimen], 35598).

A MONOGRAPH OF THE EXISTING CRINOIDS 17

Menaclo Bay, northern Celebes (lat. 1°31' N., long. 124°47' E.); 457 meters;
Captain Christiansen, Great Northern Telegraph Company, March 12, 1912 (18,
U.S.N.M., E. 3215; C. M.).

Albatross station 5617; Moluccas; Ternatc Island (S. E.) bearing S. 45° W., 7
miles distant (lat. 0°49'30" N., long. 127°25'30" E.); 239 meters; Nov. 27, 1909 (1,
U.S.N.M., 36030).

Challenger station 192; near the Kei Islands (lat. 5°49'15" S., long. 132°14'15"
E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hartlaub, 1891,
1912; A. H. Clark, 1907, 1909, 1911, 1912, 1913, 1918; Gisl6n, 1934] (3, B. M.).

Rotti Strait, between Timor and Rotti; 183 meters; from the Banjuwangi-Darwin
No. 2 cable; cable repair ship The Cable, Eastern and Associated Telegraph Co. [A. H.
Clark, 1929] (3, B. M.).

Geographical range. — From the Philippines to the Kei Islands and Timor.

Bathymetrical range. — From 183 to 457 meters.

History. — This species was first described under the name of Antedon quinquecostata
by Dr. Philip Herbert Carpenter in 1888 from eight specimens and two fragments that
had been dredged by the Challenger at station 192. Carpenter discussed the species
at considerable length comparing it especially with A. (Stylometra) spinifera, and also
with A. (Aglaometra) valida. He dissected one of the specimens and described and
figured the central calcareous structures in detail.

In 1891 Dr. Clemens Hartlaub compared Antedon quinquecostata in some detail
with his new species A. (Cosmiometra) conifera. In 1907 I referred quinquecostata to
the new genus Thalassometra, and in 1909 I described the new genus Stenometra with
Antedon quinquecostata as the genotype. Later in the same year in discussing the
new species Stenometra dorsata (=diadema) I wrote:

At first I considered this species the same as the earlier quinquecostata of Carpenter; but it is
certainly true that the number of cirrus joints in Japanese specimens is considerably less than in
those from the Ki Islands, and, as this appears to be perfectly constant, there seems to be no doubt
that I was in error, and that the two are in reality perfectly distinct. This form appeared to me to
be covered by the name conifera of Hartlaub; but a personal examination of the unique type of that
species, which is in the Berlin Museum, showed me that conifera is in reality a species of Cosmiometra,
allied to C. crassicirra of Hawaii.

In 1911 I described Stenometra cristata from five specimens from Albatross station
5275, comparing it with <S. dorsata (=diadema) from southern Japan. There can be
little doubt that S. cristata is based upon individuals of S. quinquecostata that have not
attained their full development. At the same time I noted that S. quinquecostata
resembles S. dorsata (=diadema) in having short cirrus segments, but it differs hi
having a considerably larger number. Further information has proved this statement
incorrect.

In 1912 Hartlaub compared Antedon quinguecostata in detail with A. (Stylometra)
spinifera. His information regarding quinquecostata was taken from Carpenter's
account in the Challenger report, but he had before him many specimens of spini/era.
In my memoir on the crinoids of the Indian Ocean published later in 1912 I listed
Stenometra quinquecostata and gave the range.

18 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In a memoir on the crinoids of the British Museum published in 1913 I gave notes
on three specimens from Challenger station 192 that I had examined in 1910. In my
report on the unstalked crinoids of the Siboga expedition published in 1918 quinque-
costata was included in a key to the species of Stenometra, and the range and synonymy
were given. In 1929 I recorded and gave notes on two specimens that had been found
on a cable in Rotti Strait in 100 fathoms by the Eastern and Associated Telegraph
Company's cable repair ship The Cable. At the same time I described in detail under
the name of Stenometra diplax another specimen from the same locality which is un-
doubtedly merely an aberrant individual of S. quinquecostata. In 1934 when recording
a number of species in the Raffles Museum, Singapore, collected by the cable repair
ship The Cable, I mentioned Stenometra diplax as one of the new species that had been
collected by that ship in previous years.

In 1934 Prof. Torsten Gislen discussed the arm division of Stenometra quinque-
costata which he placed in his type 42, the Stephanometra spicata type.

STENOMETRA DIADEMA (A. H. Clark)

PLATE 2, FIGURE 5
[See also vol. 1, pt. 1, figs. 191, 192, p. 237; pt. 2, fig. 211, p. 152.]

Antedon quinquecostata A. H. CLABK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 129 (comparison, in
key, with A. diadema), p. 143 (comparison with A. [Parametra] oriori), p. 145 (comparison with
A. [Cosmiometra] aster; considered as including A. [Cosmiometra] conifera).

Antedon diadema A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 144 (description; Albatross
station 4934); vol. 34, 1908, p. 468 (listed).

Thalassometra quinquecostata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (in
part; listed); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 310 (various localities in Sagami Bay).

Thalassometra diadema A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Proc. U. S. Nat. Mus., vol. 34, 1908, p. 318 (Japan).

Stenometra diadema A. H. CLARK, Proc. Bio]. Soc. Washington, vol. 22, 1909, p. 15 (listed) ; Crinoids
of the Indian Ocean, 1912, p. 210 (synonymy; locality) ; Unstalked crinoids of the Siboga-Exped.,
1918, p. 156 (in key; range); p. 157 (synonymy). — GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis,
ser. 4, vol. 5, No. 6, 1922, p. 118 (compared with S. dentata); Zool. Bidrag Uppsala, vol. 9, 1924,
p. 44; Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 83, 1927, p. 3 (stations 7, 9; 162-198
meters), p. 39 (stations 7, 9; notes), p. 68 (listed), figs. 34, 35, p. 44; Kungl. Fysiogr. Sallsk.
Hand!., new ser., vol. 45, No. 11, 1934, p. 20.— A. H. CLARK, Temminckia, vol. 1, 1936, p. 315.

Stenometra quinquecostata (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15
(listed).

Stenometra dorsala A. H. CLARK, Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 186 (description;
near Nagasaki, 170 fathoms; "Eastern Asia"; compared with S. quinquecostata and with Cosmio-
metra conifera); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 553 (compared with S. cristata); Crinoids
of the Indian Ocean, 1912, p. 123 (parasitic Eulima), p. 210 (synonymy; locality); Proc. Biol.
Soc. Washington, vol. 26, 1913, p. 179 (range in eastern Asia); Journ. Washington Acad. Sci.,
vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance); Die Crinoiden
der Antarktis, 1915, p. 125 (shows characteristic features of Anthomelra adriani); Unstalked
crinoids of the Sifcojo-Exped., 1918, p. 157 (identity).

Diagnostic features. — The elements of the division series and first two brachials
have the proximal and distal edges unmodified and the lateral borders smooth or prac-
tically so; and the crest in profile is coarsely denticulate, on the IBr! usually deeply
bilobate. The 15-20 (almost always 20) arms are 65-80 mm. long, and the longest
cirri are 38-50 mm. long with 55-78 segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 19

Description. — The type series was composed of small individuals which were thus
described. The centrodorsal is long and columnar, with the tip conical. The cirrus
sockets are arranged in 10 columns of 2 each, the sockets of one column alternating with
those of the adjoining columns.

The cirri are XX, 50-55, 25 mm. long. The segments in the basal half, except
for the proximal, are elongate, those in the distal half short with prominent dorsal
spines.

The basals are just visible as small interradial tubercles.

The radials are rather long. The IB^ are about the size of the radials, and the
IBr2 (axillaries) are widely pentagonal, broader than long; both have a high and sharp
median keel. The IIBr series are 2, like the IBr series and with a prominent keel.

The 11-18 arms are 30 mm. long (only one-fifth longer than the cirri). The first
8 brachials are oblong, rather long, those following becoming wedge-shaped. All
the brachials are strongly carinate and laterally compressed. After the basal third
the arms become very narrow and the brachials begin to develop overlapping dorsal
spines.

P, is considerably the largest pinnule and is composed of 8-10 elongated segments.
The pinnules following decrease in length to P6 or Pa, then slowly increase in length
distally.

The color in life is bright yellow.

In fully grown individuals the arms are 19-20 (usually 20), about 80 mm. long;
the cirri are composed of about 70 segments and are 45-50 mm. long.

Notes. — In a specimen from Mortensen's station 7, according to Gislen, the cen-
trodorsal is a high cone 2.8 mm. broad at the base and 2.6 mm. high. The bare dorsal
pole is 2.4 mm. in diameter and is covered with pits and tubercles. There are 5 strong
interradial ridges. The cirrus sockets are arranged in 10 columns of 2 or 3 each. There
is a tubercle on each side of the nerve lumen.

The cirri are XXIII, 57-78, 25-45 mm. long. The sixth-seventeenth cirrus
segments are slightly longer than broad. Dorsal spines are developed from the fifteenth
onward.

The radials are visible in the interradial angles of the calyx. The IBr, are five
times as broad as long with an abrupt high bidentate crest in the median line. The
IBr2 (axillaries) are twice as broad as long with a median sharp and simple crest in the
proximal three-fourths, and a synarthrial backward projection. The IIBr series are
2 with a carination similar to that of the IBr series but lower and not serrate.

The 20 arms are all broken. The carination continues to the ends of the arms.
Overlapping dorsal spines are developed from the fifth brachial onward.

The distal intersyzygial interval is 5-7 muscular articulations.

PI is 11 mm. long with 19-20 segments. P2 is 8 mm. long with 13 segments. P»
is 7.5 mm. long with 12 segments. P4 is 4.5 mm. long with 8 segments. P6 is 3.7 mm.
long with 7 segments. The distal pinnules are 7 mm. long with 16 segments.

The disk is 7. 5 mm. in diameter with sparse calcareous granules along the ambulacral
furrows. The anal cone is 2 mm. high and bears granules.

The color in alcohol is brown, the ossicles somewhat brighter.

Another specimen from Mortensen's station 7 has the cirri XIX, 59-77, 26-38
mm. long. The 20 arms are 65 mm. long. PI is 6.2 mm. long with 1 1 segments.

20 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

P2 is 4.7 mm. long with 8 segments. P3 is 3 mm. long with 7 segments. P4 has 6
and P5 has 7 segments. The distal pinnules are 5.5 mm. long with 14 segments.

A third specimen from Mortensen's station 7 has the cirri XXI, 44-61, 22-31
mm. long; the longest cirrus segments is one-third again as long as broad. The 15
arms are 70 mm. long. Pt has 11 segments, P2 has 8 segments, and P3 has 6 segments.
The distal pinnules are about 5 mm. long with 10-12 segments.

A specimen from Mortensen's station 9, according to Gislen, has the cirri about XX,
58, 28 mm. long. The 15 arms are all broken. The proximal crest is tolerably even
with notches only at the articulations. PI is 5.5 mm. long with 11 segments. The
disk is incised, 3.5^1.5 mm. in diameter. The anal cone is 1.5 mm. high.

Two dried 10-armed young from Mortensen's station 9 have the arms about 30
mm long; one cirrus in the smaller specimen is 17 mm. long with 44 segments.

Professor Gislen wrote that the appearance of the cirrus sockets is interesting as
it presents similarity with those of certain cretaceous comatulids in the families Noto-
crinidae and Conometridae, and the Essenensis and Paradoxus groups of Glenotremites.

The specimens from Sagami Bay collected by Alan Owston are yellow with a broad
line on the division series and arms and a lateral line on the arms white; the cirri are
banded yellow and white, and the pinnules are blotched yellow and white.

One of the specimens from Albatross station 3719 has 20 arms 80 mm. long and the
cirri 45 mm. long.

Parasite. — Professor Gislen noted that a specimen from Mortensen's station 7
was infested with a parasitic gastropod of the genus Eul"ma (see Part 2, page 649,
Melanella sp.).

Localities.— Sagami Bay, Japan (lat. 35°04' N., long. 138°48' E.); 146 meters;
Alan Owston, yacht Golden Hind, August 8, 1902 [A. H. Clark, 1908] (1, U.S.N.M.,
35616 [original No. 7196]).

Sagami Bay (lat. 35°03' N., long. 138°47' E.); 201 meters; Alan Owston, yacht
Golden Hind [A. H. Clark, 1908] (1, U.S.N.M., 35615 [original No. 7189]).

Sagami Bay; off Yenoshima; Alan Owston, yacht Golden Hind, April 1896 [A. H.
Clark, 1908] (1, U.S.N.M., 35600 [original No. 6275]).

Albatross station 3719; off Honshu Island, Japan; Ose Zaki bearing S. 13° W.,

1.5 miles distant; 128-165 meters; volcanic sand, shells, and rock (3, M. C. Z., 64, 300).

Albatross station 3755; off Honshu Island, Japan; Suno Said bearing S. 63° E.,

3.6 miles distant; 95-141 meters; gray sand and coral; May 19, 1900 (1, U.S.N.M.,
35610).

Albatross station 4936; Eastern Sea, off Kagoshima Gulf; Sata Misaki Light
bearing N. 21° E., 5.7 miles distant (lat. 30°54'40" N., long. 130°37'30" E.); 188
meters; stones; bottom temperature 15.9° C.; August 16, 1906 (1, U.S.N.M., 35611).

Albatross station 4934; Eastern Sea, off Kagoshima Gulf; Sata Misaki Light
bearing N. 77.5° E., 7 miles distant (lat. 30°58'30" N., long. 130°32'00" E.); 188-288
meters; rocky bottom; bottom temperature 13.3° C.; Aug. 16, 1906 [A. H. Clark, 1907]
(3, U.S.N.M., 22637 [type of Antedon dia.dema], 35599).

Eastern Sea, near Nagasaki (lat. 32°22' N., long. 128°42' E.); 311 meters; Captain
Suensson, November 23, 1901 [A. H. Clark, 1909] (2, C. M.).

Albatross station 4890; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Said Light bearing N. 2° W., 10 miles distant (lat. 32°26'30" N.,

A MONOGRAPH OF THE EXISTING CRINOIDS 21

long. 128°36'31"E.); 247 meters; rocky bottom; bottom temperature 11.3° C.; August
9, 1906 (1, U.S.N.M., 35614).

Albatross station 4900; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 10° E., 8 miles distant (lat. 32°28'50" N.,
long. 128°34'40" E.); 254 meters; gray sand and broken shells; bottom temperature
11.6° C.; August 10, 1906 (1, U.S.N.M., 35613).

Albatross station 4893; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 29° E., 5.5 miles distant (lat. 32°32'00" N.,
long. 128°32'50" E.); 174-194 meters; gray sand, broken shells, and pebbles; bottom
temperature 13.3° C.; August 9, 1906 (1, U.S.N.M., 35612).

Dr. Th. Mortensen's Pacific Expedition station 9; off Kin Shiu, Japan (lat. 32°15'
N., long. 128°12' E.); 165 meters; hard bottom; May 15, 1914 [Gislen, 1922, 1924,
1927, 1934].

Dr. Th. Mortensen's Pacific Expedition station 7; off Kiu Shiu, Japan (lat. 32°17'
N., long. 128°11' E.); 201 meters; sand; May 14, 1914 [Gislen, 1922, 1924, 1927, 1934].

Eastern Asia; Captain Suensson, July 29, 1900 [A. H. Clark, 1909, 1913] (1, C.M.).

Geographical range. — Southern Japan from the Korean Straits to Sagami Bay.

Bathymetrical range. — From 141 (?95) to 311 meters; the average of 11 records is
199 meters.

Thermal range.— From 11.3° to 15.9° C.

History. — During the cruise of the United States Fisheries steamer Albatross in
Japanese waters in 1906 I collected a number of specimens of this species at five different
stations in the Eastern Sea. These I identified with Carpenter's Antedon quinqueco-
stata, except for three small individuals from station 4934 which I described as a new
species under the name of Antedon diadema in 1907. In the same paper I inserted
Antedon quinquecostata in a key to the new species described for comparison with
A. diadema. The two species were said to be differentiated by the occurrence of 70-90
slender cirrus segments in quinquecostata, whereas diadema has only 50-55 stout cirrus
segments. Antedon quinquecostata was compared with A. (Parametra) orion, sp. nov.,
and with A. (Cosmiometra) aster, sp. nov., with which species it has very little in
common. I placed Hartlaub's Antedon conifera in the synonymy of A. quinquecostata,
a proceeding that now appears wholly illogical. Later in 1907 I referred diadema and
quinquecostata to my new genus Thalassometra.

In 1908 I recorded Thalassometra quinquecostata from three localities in Sagami
Bay where it had been dredged by Alan Owston in his yacht the Golden Hind.
When in Yokohama I had met Mr. Owston, and he had shown me his fine collection of
Japanese crinoids. Later this collection was purchased by Frank Springer and deposited
in the United States National Museum.

In January 1909, I established the new genus Stenometra to which I referred
diadema and quinquecostata, the latter including Hie specimens from southern Japan.
The genotype was given as Antedon quinquecostata P. H. Carpenter, 1888, but my
idea of this species was based entirely upon Japanese specimens.

Dr. Theodor Mortensen, of the Zoological Museum, Copenhagen, Denmark,
kindly sent me for study the entire comatulid collection of that Museum. In the
collection were three specimens of the species I had identified as Antedon quinqueco-
stata that had been collected off southwestern Japan by one of the Danish cable repair

22 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ships under the command of Captain Suensson. These agreed with the specimens
I had collected in the same region and differed slightly, though apparently constantly,
from Antedon quinquecostata as described by Carpenter in the Challenger report. For
the species represented I proposed the name Stenometra dorsata, saying:

I at first considered this species the same as the earlier quinquecostata of Carpenter; but it ia
certainly true that the number of cirrus joints in Japanese specimens is considerably less than in those
from the Ki Islands, and, as this appears to be perfectly constant, there seems to be no doubt that
I was in error, and that the two are in reality perfectly distinct. This form appeared to me to be
covered by the name com/era of Hartlaub; but a personal examination of the unique type of that
species, which is in the Berlin Museum, showed me that conifera is in reality a species of Cosmiometra,
allied to C. crassicirra of Hawaii.

In 1911 I described a new species, Stenometra cristata, from the Philippines, com-
paring it with S. dorsata,. I noted that in S. dorsata the carination of the division series
and lower brachials is irregular and serrate in profile, and that S. quinquecostata resem-
bles S. dorsata in having short cirrus segments, though it diff ers in having a considerably
larger number. In my memoir on the crinoids of the Indian Ocean published in 1912
I listed both Stenometra dorsata and S. diadema, giving the synonymy and range of
each. In a paper on the comatulid fauna of eastern Asia based chiefly upon the col-
lections of Captain Suensson, in charge of one of the Danish cable repair ships, published
in 1913, I listed Stenometra dorsata as from "East Asia (probably the Korean Straits)."
This is a repetition of the record published in 1909. In 1915 in a paper on the bathy-
metrical and thermal distribution of the unstalked crinoids or comatulids occurring on
the coasts of China and Japan the bathymetrical range of Stenometra dorsata was given
as 52-170 fathoms, and the thermal range as from 11.28° to 15.89° C. Although it
is not so stated, S. dorsata was regarded as including diadema. In my memoir on the
crinoids of the Antarctic published in 1915 I pointed out that the characteristic features
of Anthometra adriani of the subfamily Heliometrinae, family Antedonidae, are well
developed in various other types, among them Stenometra dorsata and related species.
In my memoir on the unstalked crinoids of the Siboga expedition published in 1918
diadema was included in the key to the species of Stenometra, and its range was given
as southern Japan in 91-306 meters. Under Stenometra diadema were listed the
records of Thalassometra quinquecostata from southern Japan published in 1908, and
Stenometra dorsata was included in diadema as a synonym.

In 1922 Prof. Torsten Gislen compared Stenometra diadema with his new species
S. dentata from the Bonin Islands, and in 1924 he called attention to the reversion
phenomenon as illustrated by S. diadema, of which he had before him some unrecorded
specimens that had been collected by Dr. Theodor Mortensen off southwestern Japan.
In 1927 he recorded and gave notes on three specimens from Dr. Mortensen's Pacific
Expedition station 7, and three, including two 10-armed young, from station 9. In
1934 he discussed the arm division of Stenometra diadema which he placed in Type 21,
the Stenometra diadema type. The specimens he had before him were some in the
Lund Museum received from Dr. Mortensen.

In 1936 I compared Stenometra diadema with a new species, S. snelliusi, from
Ceram.

A MONOGRAPH OF THE EXISTING CRINOIDS 23

Genus DAIDALOMETRA A. H. Clark

Anledon (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 137.

Thalasso metro, (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.

Stcnometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15.

Stiremelra (part) A. H. CLARK, Die Fauna Siidwest-Australiens, vol. 3, Lief. 13, 1911, pp. 440, 443.

Daidalometra A. H. CLARK, Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (no diagnosis;
name used in combination with [Antedon] hana); vol. 6, No. 5, 1916, p. 116 (diagnosis; genotype
Antedon hana A. H. Clark, 1907; comparison of arms with those of Stenomelra) ; Unstalked
crinoids of the Sj'6o0a-Exped., 1918, p. 146 (in key; range), p. 147 (same), p. 157 (key to the
included species). — GISL£N, Nova Acta Ilcg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, pp. 9,
118; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20.

Diagnosis. — A genus of Thalassometridae in which the division series, which are all
2, and arms are laterally compressed and sharply carinate, gablelike in cross section, the
brachial carination being produced into high crests or broad overlapping spines; the arms
in fully developed individuals are 10-18 (usually 10-15) in number, 60-65 mm. long;
PI resembles P2 but is somewhat longer and proportionately stouter; the cirri are long,
slender, and delicate, 20-24 mm. long with 32-75 segments, and are arranged in 10
columns on a small conical or truncated conical centrodorsal.

Geographical range. — From Port Denison, Queensland, to Timor and northward to
southwestern Japan.

Bathymetrical range. — From 22 to 548 meters.

Remarks.— The genus Daidalometra is very closely related to Stenometra and per-
haps should not be separated from it. There appear to be no real differences between
the two other than in the number of arms, and in this feature there is a certain amount of
overlapping between occasional individuals of some species. The three species of
Daidalometra appear to be well characterized, although all three are known from only a
small number of individuals.

History. — The genus Daidaometra was established in 1916 with the genotype Ante-
don hana A. H. Clark, 1907. The two species included in it at the time of the original
description were D. hana and D. acuta. In 1918 a key to the two included species was
given, with acuta regarded as a synonym of the earlier arachnoides.

In 1922 in his description of Stenometra dentata Prof. Torsten Gislen wrote that this
new species approaches Daidalometra (hana), a genus properly distinguished from
Stenometra only by a smaller number of arms. He said that S. dentata is to a certain
extent a transition between these two genera.

KEY TO THE SPECIES IN THE GENUS DAIDALOMETRA

a1. Cirri short, not more than half the length of the arms, with not more than 65 segments; arms 60-65

mm. long.

61. Cirri with 49-65 segments; division series and proximal brachials with a narrow, sharp, and high
median carination, the ossicles with everted and spinous edges; 10-18 (usually 10-13) arms
(Queensland to Timor and northward to the Sulu [Jol6] Archipelago; 22-118 meters).

arachnoides (p. 25)

6*. Cirri with 32-39 segments; carination of the division series and arm bases low with a rounded
crest; edges of the elements of the division series and proximal brachials little modified; 10

arms (Zamboanga, Mindanao; about 548 meters) eurymedon (p. 24)

a?. Cirri longer, more than two-thirds of the length of the arms, 40-45 mm. long with 68-77 segments;
arms 10-11, 60 mm. long (southwestern Japan; 196-254 meters) hana (p. 27)

24 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

DAIDALOMETRA EURYMEDON. up- »ov.

Diagnostic features. — The cirri are short, considerably less than half the length of
the arms, with 32-39 segments; the carination of the division series and arm bases is
low, with a rounded crest; and the proximal and distal borders and the lateral edges of
the elements of the division series and first two brachials are sparsely spinous or tuber-
cular. The 10 arms are about 65 mm. long, and the cirri are up to 24 mm. long.

Description. — The centrodorsal is conical, with the truncated apex bearing in the
center a group of six long blunt spines, of which one is centrally situated and the other
five are radially placed about it. The cirrus sockets are arranged hi 10 columns of
usually 2 each. The two columns in each radial area are more or less separated proxi-
mally in the midradial line, but are hi contact apically. The columns are everywhere
closely crowded against each other interraclially.

The cirri are XX, 32-39, up to 24 mm. in length. The first segment is very short,
the second is longer, the third is from twice as broad as long to slightly longer than
broad. In the longest cirri the fourth segment is as long as, or slightly longer than,
broad, and the fifth is a transition segment, from two and one-half to three times as
long as the median width. The segment following is of about the same length, slightly
longer or slightly shorter, and those succeeding decrease hi length so that the segments
in the outer half of the cirri are about as long as broad, becoming more or less longer
than broad distally. In the shorter cirri the fourth is the transition segment. The
midventral line of the first four segments and of the proximal portion of the transition
segment is more or less narrowly gabled, though never sharply carinate. The distal
dorsal edge of the transition segment is slightly produced. This production of the
dorsal portion of the distal edge slowly increases hi amount, and in the outer quarter
of the cirri becomes a high carinate dorsal spine.

The radials are rather long, being about three times as broad as the median length.
The distal border is everted and more or less irregular, and there is a high and abrupt
narrowly rounded median keel or tubercle. The IBrj are about four times as broad as
the median length. The lateral borders are hi contact, and the anterolateral angles
are sharply cut away. The median portion rises into a sharply rounded median cari-
nation which is very distinct, though much lower than that on the radials, and the
lateral portions of the distal border bear usually two conspicuous short blunt spines
or tubercles. The IBr2 (axillaries) are rhombic, nearly twice as broad as long, with a
prominent thin lateral flange under each of the lateral angles, a roundedly carinate
elevation hi the proximal half or two-thirds corresponding to that on the IBri, and a
few blunt spines or tubercles on the proximal border just above those on the distal
border of the IBr^

The 10 arms are about 65 mm. long. The first two brachials bear a narrow flange
on the outer side by which they are just in contact. The first brachials may have
minute denticulations on the distal border. The earlier brachials are rather abruptly
rounded in the middorsal line, this feature being most marked on the first two ; but they
can scarcely be called carinate. The brachials in the outer half of the arm have the
median portion of the distal edge greatly produced and tipped with a comb of spines,
so that the dorsal profile of the outer half of the arms is very strongly serrate.

A MONOGRAPH OF THE EXISTING CRINOIDS 25

PI is much enlarged, and is much larger than the pinnules succeeding. It is com-
posed of 12 segments of which the third is greatly broadened. From this it tapers to
the base, and also distally, the terminal five segments being exceedingly small.

Notes. — The second specimen resembles that described, except that the spinosity
of the dorsal pole of the centrodorsal is much less developed; there are 32-34 cirrus
segments.

These specimens are evidently young, and the characteristic features of the
species have not as yet become fully accentuated.

Locality.— Dr. Th. Mortensen's Pacific expedition, 1914-1916; 7 miles south of
Olutanga Island, east of Zamboanga, Mindanao, Philippine Islands; about 548 meters;
hard bottom; March 3, 1914 (2, C. M.).

DAIDALOMETRA ARACHNOIDES (A. H. Clark)

PLATE 3, FIGURE 12
[See also vol. 1, pt. 1, fig. 205, p. 239; pt. 2, fig. 744, p. 349.]

Stenometra arachnoides A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 402 (description;
Albatross station 5154; ?Port Denison, Queensland).

Stiremetra arachnoides A. H. CLARK, Die Fauna Siidwest-Australiens, vol. 3, Lief. 13, 1911, p. 440
(range), p. 443 (range on east coast); Mem. Australian Mus., vol. 4, 1911, p. 721 (south to Port
Denison), p. 789 (synonymy; history; range) ; Crinoids of the Indian Ocean, 1912, p. 213 (synon-
ymy; localities); Internal. Rev. gesamt. Hydrobiol. Hydrogr., 1915, p. 223 and following (dis-
tribution in Australia).

Stenometra acula A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 428 (description; Siboga station
294); Unstalked crinoids of the Siboga-Exped., 1918, p. 157 (identity).

Daidalometra acuta A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 5, 1916, p. 116 (range).

Daidalomelra arachnoides A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 157 (in key
range; synonymy; notes; stations 166, 294), pp. 273, 275 (listed), pi. 23, fig. 60.

Diagnostic features. — The cirri are short, not more than half the arm length, with
49-65 segments; and the elements of the division series and first two brachials have a
narrow, sharp, and moderately high median carination and abruptly everted and
coarsely spinous edges. The 10-18 (usually 10-13 and most commonly 10) arms are
60 mm. long, and the cirri are 20-30 mm. long

Description. — The centrodorsal is moderate in size, columnar, broader basally than
long, decreasing slightly in width distally. The bare polar area is 2 mm. in diameter.
The cirrus sockets are arranged in 10 closely crowded columns of 2 each.

Cirri XX (XII in the type), 61-65, 30 mm. long. The first 4 segments are subequal,
averaging twice as broad as long, rather prominently overlapping all around. The
fifth segment is nearly half again as long as broad, a more or less marked transition
segment. The sixth is of about the same length or slightly shorter. The next 5
segments are about as long as broad, and those succeeding gradually decrease in length
so that those in the distal half of the cirri are twice as broad as long or even slightly
shorter. The fourteenth or fifteenth and following segments bear prominent dorsal
spines.

The disk and ambulacra are well plated.

The ends of the basal rays are visible as dorsoventrally elongate tubercles in the
interradial angles of the calyx.

843803 — 50 3

26 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The radials are entirely concealed by the centrodorsal, or their distal coarsely
epinous borders are just visible over the ends of the basal rays. The IBri are very
narrow, chevron-shaped, with abruptly everted and coarsely spinous edges; they are
in close lateral apposition. The IBr2 (axillaries) are rhombic, twice as broad as long,
with the edges concave, and abruptly everted and coarsely spinous all around. There
is a high and sharp median keel in the proximal two-thirds.

The 10 arms are all broken off at the base. The first 2 brachials externally and
the second and third internally are sharply flattened laterally. The first brachials are
ulteriorly united. The second brachials are large, shield-shaped, deeply incising the
very narrow first brachials. The first 2 brachials have more or less everted and
coarsely spinous edges. The arms have a very narrow, sharp, and moderately high
median carination.

The pinnules resemble essentially those of S. hana.

Notes. — Of the four specimens from Siboga station 166 one has 10 arms and cirri
with 54 segments; another has 13 arms about 60 mm. long and cirri with 49-54 seg-
ments, 20-25 mm. long; the other two have 16 and 18 arms.

The specimen from the Danish Expedition to the Kei Islands station 24 has the
cirri XIX, 57-61, about 30 mm. long; there are 13 arms, all broken. The division series
and arms have a low and very narrow, though prominent, median keel.

In my diagnosis of Stenometra acuta from Siboga station 294 I said that this species
is most closely related to S. hana of Japan, but it is at once distinguishable from that
form by the much shorter cirri which have fewer segments; the carination of the
proximal brachials is somewhat sharper and more prominent than in S. hana. The
type specimen has the cirri XII, 51-58, 25 mm. long; the first three segments (sometimes
also the fourth) bear dorsally a fine median carination ending dis tally in a small spine
as in S. hana. The 12 arms are about 60 mm. long. The other specimens from Siboga
station 294 are all small with 10 arms.

Localities. — Albatross station 5154; Tawi Tawi Group, Sulu (Jol6) Archipelago;
Bakun Point bearing S. 11° W., 0.7 mile distant (lat. 5°14'50" N., long. 119°58'45"
E.); 22 meters; coral sand; February 19, 1908 [A. H. Clark, 1909, 1912, 1918] (1,
U.S.N.M., 25470).

Siboga station 166; Ceram Sea (lat. 2°28'30" S., long. 131°03'18" E.) ; 118 meters;
hard coarse sand; August 22, 1899 [A. H. Clark, 1918] (4, U.S.N.M., E. 413; Amsterdam
Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 24; Kei Islands;
100 meters; April 15, 1922 (1, C. M.).

Siboga station 294; Timor Sea (lat. 10°12'12" S., long. 124°27'18" E.); 73 meters;
soft mud with very fine sand; January 23, 1900 [A. H. Clark, 1912, 1918] (6, Amsterdam
Mus.).

Port Denison, Queensland [A. H. Clark, 1909, 1911, 1912, 1918] (1, U.S.N.M.,
17862).

Geographical range. — From the Sulu (Jol6) Archipelago southward to the Ceram
and Timor Seas and Port Denison, Queensland.

Bathymetrical range. — From 22 to 118 meters.

A MONOGHAPH OF THE EXISTING CRINOIDS 27

History.— This species was originally described in 1909 under the name of Steno-
meira arachnoides from a specimen from Albatross station 5154. At the same time I
noted that:

A much mutilated specimen found in a jar with a specimen of Amphimetra discoidea (and therefore
probably taken in shallow water), from Port Denison, Australia, certainly belongs to this genus, and
possibly to this species. It is slightly smaller than the type, with the keels less produced, and with the
epinous edges of the lower joints less pronounced, differences which are in all probability due to
immaturity.

I remarked that the occurrence in the East Indian region of a littoral species of
Thalassometridae, a family there and elsewhere especially characteristic of the deep
water "Oceanic" faunal division is a fact of very considerable interest. In a memoir
on the recent crinoids of Australia published in 1911 I noted that a specimen of Stire-
metra arachnoides was found in the jar containing the type specimen of Amphimetra
discoidea. The United States National Museum had received these crinoids many
years before in exchange from the Australian Museum. They were collected at Port
Denison. In my report on the crinoids collected by the Hamburg Southwest Australian
Expedition in 1905, which was published in 1911, I listed Stiremetra arachnoides and
gave the range. In my memoir on the crinoids of the Indian Ocean published in 1912
Stiremetra arachnoides was included, and the synonymy and range were given. In 1912
I gave a brief diagnosis of a new species, Stenometra acuta, from Siboga station 294.
In 1915 I again gave the range of Stiremetra arachnoides. In 1916 I described the new
genus Daidalometra and listed Daidalometra arachnoides as one of the two included
species. In my report upon the unstalked crinoids of the Siboga Expedition published
in 1918 I recorded four specimens of Daidalometra arachnoides from station 166 and six
specimens from station 294. Under Daidalometra arachnoides I included Stenometra
acuta, originally described from a specimen from station 294, as a synonym.

DAIDALOMETRA HANA (A. H. Clark)

PLATE 4, FIGDHE 13
[See also vol. 1, pt. 1, fig. 212, p. 153.]

Anledon hana A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 137 (description ; Albatross station

4903).
Thalassometra hana A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed) ; Proc.

U. S. Nat. Mus., vol. 34, 1908, p. 318 (Japan).
Stenometra hana A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed) ; Zool. Anz.,

vol. 39, No. 11/12, 1912, p. 428 (compared with S. acuta [Daidalometra arachnoides]) ; Crinoids of

the Indian Ocean, 1912, p. 210 (synonymy; locality).
Daidalometra hana A. H. CLARK, Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern

Japanese species ; range and its significance) ; vol. 6, No. 5, 1916, p. 116 (range) ; Unstalked crinoids

of the Siboga-Exped., 1918, p. 157 (in key; range; references). — GISL£N, Nova Acta Reg. Soc.

Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 118 (compared with Stenometra dentata).

Diagnostic features. — The cirri are slender and long, more than two-thirds the arm
length, with 68-77 segments; and the elements of the division scries and first two bra-
chials have a rather low and strongly rounded median carination and their borders are
little or not at all modified. The 10-11 (usually 10) arms are 60 mm. long, and the cirri
are 40-45 mm. long.

28 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Description. — The centrodorsal is low hemispherical or rounded discoidal with the
apical area spinous, bearing 10 columns of cirrus sockets, 2 to each column.

The cirri are XX, 65-75, from 40 mm. to 45 mm, in length. The first 4 or 5 seg-
ments are very short, and those following are longer than broad, the seventh-ninth,
which are the longest, being somewhat less than twice as long as broad. The succeeding
segments gradually become shorter, about as long as broad just beyond the middle of
the cirrus and very short distally. Dorsal spines are developed in the distal third of
the cirri.

The disk, and the brachial and pinnule ambulacra are well plated.

The ends of the basal rays are visible as small tubercles in the angles of the calyx.

The radials are very short, crescentic, and are furnished with a fringe of spines
along the superior border. The IBri are very short, deeply incised by the axillaries,
and are furnished with a fringe of teeth about their entire edge. The IBr2 (axillaries)
are rhombic, about twice as broad as long, with the sides slightly incurved and with a
strong rounded median keel in the proximal half which continues into a similar keel
on the first brachials.

Arms 10-11 (in all but one case 10) in number, 60 mm. long. The first 8 brachials
are roughly oblong with irregular lateral dentate processes and a faintly marked median
keel which is most prominent on the first and second. The following brachials are wedge-
shaped becoming gradually shorter and more compressed laterally and developing a
sharp median keel and long median overlapping spines. The terminal brachials become
longer again. The elements of the division series and the first 4 brachials are sharply
flattened laterally and are in close lateral apposition.

Pi is the longest, about 5 mm. in length, very stout, composed of 8-10 segments
of which the basal 5 are large, massive, and about as long as broad and the remainder
are small and rapidly diminish in size. This pinnule is very sharply prismatic and
strongly flattened exteriorly; its distal border is furnished with a strong lateral ridge
on either side having a more or less deep groove between. The following pinnules
decrease in length to P5 which is 3.5 mm. long with the first segment large and about
as long as broad and the remainder tapering rapidly to a point, then gradually increase
distally becoming rather slender and reaching a length of about 8 mm. with 15-18
segments of which the first 2 are enlarged and the remainder are somewhat longer
than broad. All the pinnules are prismatic and strongly carinate.

Locality. — Albatross station 4903; Eastern Sea, between 10 and 20 miles southwest
of the Goto Islands; Ose Saki Light bearing N. 22° E., 6 miles distant (lat. 32°31' 10"N.,
long. 128°33'20" E.); 196-254 meters; gray sand and broken shells; August 10, 1906
[A. H. Clark, 1907, 1908, 1909, 1912, 1915, 1918; Gislen, 1922] (5, U.S.N.M., 22632
[type], 35595).

History. — This species was described under the name of Antedon hana in 1907
from five specimens that had been dredged by the Albatross at station 4903 in the pre-
ceding year. Later in 1907 it was transferred to the new genus Thalassometra, and in
1908 it was listed from Japan as Thalassometra hana. In 1909 it was transferred to the
new genus Stenometra, and hi 1912 it was compared with the new species Stenometra
acuta (=Daidalometra arachnoid es) . Later in 1912, in my memoir on the crinoids of
the Indian Ocean, it was listed and the synonymy and range were given.

A MONOGRAPH OF THE EXISTING CRINOIDS 29

In 1915 the new genus Daidalometra was created for its reception, and in 1916 the
range was again given. In my memoir on the unstalked crinoids of the Siboga ex-
pedition published in 1918 it was included in a key to the species of the genus Daidalo-
metra, and was listed with its range and synonymy. In 1922 Prof. Torsten Gisl6n
compared it with his new species Stenometra dentata.

Genus STYLOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Bull. Mus. Comp. Zool., vol. 9, No. 4, 1881, p. 158, and following
authors.

Thalassomeira (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.

Slylometra A. H. CLARK, Bull. Mus. Comp. Zool., vol. 51, No. 8, 1908, p. 245 (characters; genotype
Antedon kpinifera P. H. Carpenter, 1881) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 211 (referred to
the Thalassometridae), p. 212 (occurs in the West Indies); Amer. Nat., vol. 42, No. 500, 1908,
p. 542 (characteristic oceanic genus); Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same); Proc.
Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed, with its component species); Proc. U. S. Nat.
Mus., vol. 40, 1911, p. 10 (represents in the West Indies the East Indian Cosmiometra) ; Crinoids
of the Indian Ocean, 1912, p. 13 (corresponds to the East Indian Cosmiometra) ; Internat. Rev.
Gesamt. Hydrobiol. Hydrogr., 1914, pp. 4 and following (represents Cosmiometra in the Atlantic;
range); Die Crinoiden der Antarktis, 1915, p. 181 (range; corresponds to the East Indian Cosmio-
metra); Unstalked crinoids of the Siboja-Exped., 1918, p. 147 (in key; range), p. 156; Univ.
Iowa Studies in Nat. Hist., vol. 9, No. 5, 1921, p. 12 (confined to the West Indies), p. 19 (in key) ;
The Danish /nffoJ/-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range), p. 51 (in key).— GISLEN,
Zool. Bidrag Uppsala, vol. 9, 1924, pp. 74, 100.— BOONE, Bull. Bingham Oceanographic Coll.,
vol. 1, art. 4, April 1928, p. 3.— GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11,
1934.

Diagnosis. — A genus of Thalassometridae in which the division series, which are
all 2, and arm bases are rather strongly and evenly rounded dorsally, with the edges of
the ossicles armed with numerous stout spines, which may occur on the dorsal surface
also; and the brachials beyond the more or less oblong or quadrate proximal ones are
strongly carinate, the carination taking the form of a long, broad, curved, overlapping
spine. The 20-30 arms are 65-140 mm. long, and the slender cirri are 35-50 mm. long
with 40-80 segments.

Geographical range. — From the Bahamas and Greater Antilles westward to Cozumel
Island, off Yucatan, and eastward and southward along the Antillean chain to Grenada.

Bathymetrical range— From 102 to 508 (?548) meters.

Tliermal range.— From 8.33° to 23.6° C.

Remarks. — The genus Stylometra includes only a single species, S. spinifera. It is
the somewhat modified Atlantic representative of the widespread Indo-Pacific genus
Cosmiometra.

History. — The genus Stylometra was established in 1908 with the genotype Antedon
spinifera P. H. Carpenter, 1881. In my first revision of the old genus Antedon pub-
lished in 1907 Antedon spinifera had been referred to the genus Thalassometra. There
has been no change in the status of the genus Stylometra since it was first established.

30 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

8TYLOMETRA SPINIFERA (P. H. Carpenter)

PLATE 3, FIGURE 8

[See also vol. 1, pt. 1, figs. 35, p. 73, 193, 194, p. 237, 273, p. 259, 368, p. 297, 484, p. 365; pt. 2, figs.
72, 73, p. 43, 124, p. 79, 219, p. 166, 318, p. 227, 337, p. 229, 521, 522, p. 283, 743, p. 349, pi. 53,
fig. 1345.]

Antedon sp. P. H. CARPENTER, Bull. Mus. Comp. Zool., vol. 9, No. 4, 1881, p. 158 (one of the two
comatulids which appear from their abundance to be especially characteristic of the neighborhood
of the Caribbean islands, ranging from Sta. Cruz to Grenada; brought back by Duchaissaing from
Guadeloupe in 1870; obtained by the Blake at 10 stations in 80^-297 fathoms; most abundant at
station 269 off St. Vincent in 124 fathoms; also dredged in 278 fathoms off St. Lucia by the
Investigator) .

Antedon spimfera P. H. CARPENTER, Bull. Mus. Comp. Zool., vol. 9, No. 4, 1881, p. 158 (detailed de-
scription; ambulacral plating described), p. 162 (ambulacra! plating). — BELL, Proc. Zool. Soc.
London, 1882, p. 533 (listed), p. 534 (specific formula). — P. H. CARPENTER, Proc. Zool. Soc.
London, 1882 (1883), pp. 740, 746 (discussion of Bell's method of formulation and corrected
formulae). — VON GRAFF, Bull. Mus. Comp. Zool., vol. 11, No. 7, 1883, p. 129 (off Montserrat,
88 fms.; off St. Vincent, 124 fms.; myzostomes). — P. H. CARPENTER, Challenger Reports, Zool.,
vol. 11, pt. 32, 1884, p. 277, footnote (arm division). — VON GRAFF, Challenger Reports, Zool., vol.
10, pt. 27, 1884, pp. 14, 15, 19 (myzostomes), p. 44 (Blake sta. 157), p. 47 (Blake stas. 155, 269).—
LOCKINQTON, Standard Nat. Hist., vol. 1, 1884, p. 143. — A. AOASSIZ, Bull. Mus. Comp. Zool., vol.
15, reprinted as "Three Cruises of the Blake," vol. 2, 1888, p. 125, fig. 417 (general account).—
BRAUN, Centralbl. Bakteriol. und Parasitenkunde, vol. 3, 1888, p. 185 (myzostomes; after von
Graff). — P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 50 (arm division),
p. 55 (specific formula), pp. 208-211 (characters of the Spimfera group and key to the included
species), p. 216 (compared with [Stenometra] quinquecostata), p. 217 (compared with [Stiremetra]
lusitanica), p. 306 (very closely allied to quinquecostata) , p. 368 (bathymetric range), p. 379 (Carib-
bean Is., 80-297 fms.); Journ. Linn. Soc. (Zool.), vol. 21, 18S9, p. 306 (arm arrangement compared
with that of Antedon elegans [*=Zygometra comata]). — MINCKERT, Arch. Naturg., Jahrg. 71, 1905,
vol. 1, pp. 170 and following (syzygies; regeneration).- — A. H. CLARK, Proc. U. S. Nat. Mus., vol.
33, 1907, p. 152 (comparison of brachials with those of A. [Thalassometra] hawaiiensis) . —
HAMANN, Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed).- — •
HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 280 (in the Blake collection), p. 309
(in the Spinifera group; history), pp. 358-366 (synonymy; St. Lucia, Investigator; Blake stas.
155, 220, 231, 232, 249, 259, 269, 290, 292, 297, 298, 299; detailed description and discussion),
pi. 1, figs. 9, 12-16, 19, 20, pi. 2, figs. 1-12.

Thalassometra spinifera A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Stylomelra spinifera A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed); Bull.
Mus. Hist. Nat. Paris, 1911, No. 4, p. 256 (notes on Duchaissaing's specimen); Smithsonian
Misc. Coll., vol. 61, No. 15, 1913, p. 43 (Barbados); Unstalked crinoids of the Stboffa-Exped.,
1918, p. 156 (references). — H. L.CLARK, Bull. Lab. Nat. Hist., Univ. Iowa, vol. 7, No. 5. 1918,
p. 10 (Bahamas Exped. station 2) — A. H. CLARK, Univ. Iowa Studies in Nat. Hist., vol. 9,
No. 5, 1921, pp. 10, 11 (occurrence at Barbados); Smithsonian Misc. Coll., vol. 72, No. 7, 1921,
pi. 15, fig. 53 (arm), fig. 54 (syzygial pairs) ; The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea,
1923, p. 40 (range). — GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 79. — BOONE, Bull. Bingham
Oceanographic Coll., vol. 1, art. 4, April 1928, p. 3 (Pawnee I; near English Cay, Bahamas,
190 fathoms; notes). — A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929,
p. 647 (Snapper Bank; notes). — GISLEN, Kungl. Fysiograf. Sallsk. Handl., new ser., voL 45, No. 11,
1934, p. 25. — H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 8 (Atlantii
stas. 3303, 3465, 3466, 3482; notes).

Stylometra (undescribed form) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14.

Alecto terrata HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 358, footnote 1 (of Oersted,
M8=spinifera, according to A. H. Clark).

A MONOGRAPH OF THE EXISTING CRINOIDS 31

Antedon spinifera var. brevispina HARTLATJB, Mem. Mus. Comp. Zool., vol. 27, No. 4, April 1912,
p. 362, second line (characters; Montserrat, 88 fathoms [Blake station 155], and St. Lucia, 278
fathoms [Investigator] ), pi. 2, fig. 7 (St. Lucia, 278 fathoms).

Description. — The centrodorsal is very small, hemispherical or low-conical, the
bare apical area convex and spinous. The cirrus sockets are arranged in 10 crowded
columns, one or two in each column.

The cirri are XI-XX, 40-80, from 35 to 50 mm. long, or from one-third to half
the arm length. The longest cirrus segments, the sixth or seventh, are usually between
two and three times as long as broad and are centrally constricted ; the distal cirrus
segments are very short. The segments beyond the basal third of the cirri are pro-
vided with long, slender, and sharp dorsal spines.

The radials are over twice as broad as long with a prominent median spine. The
IBr, are short, between two and three times as broad as long. The IBra (axillaries)
are almost triangular. The IIBr, IIIBr, and IVBr series are 2, similar to the IBr series
but with the component ossicles progressively longer. Slight synarthrial tubercles
are present. The elements of the division series are bordered with stout spines, with
occasionally other spines scattered over the dorsal surface.

The 25-30 or more arms are from 65 to 140 mm. long. The lower brachials are
about as long as broad with parallel sides and very prominent articulations. After
about the eighth the brachials become wedge-shaped with concave anterior and pos-
terior borders, gradually becoming more elongate distally. The first eight or nine
brachials, like the elements of the division series, are bordered with stout spines, some-
times with other spines scattered over the dorsal surface. Beyond the eighth or ninth
brachial these spinous edgings become obsolete and strong, elongate, curved, and
overlapping processes develop on alternating sides of the median line. These processes
gradually approach the median line, at the same time becoming somewhat smaller,
until in the outer part of the arm they are relatively small, median in position, and
finally disappear altogether. This feature is subject to great variation; in some speci-
mens it is extraordinarily developed, in others almost entirely lacking.

Syzygies occur between brachials 3+4, again from between brachials 26 + 27 to
between brachials 32 + 33, and distally at intervals of 4-9 musuclar articulations, the
lesser number being found in the more distal portion of the arms.

In an average large specimen PI is 7 mm. long with 15 segments of which the
first two are about as long as broad and the remainder become progressively elongated.
P3 is 11 mm. long; the first segment is about as long as broad, the others elongated.
P3 resembles Pt. P4 is similar, but shorter. These pinnules are all slender and stiff.
From P5 to about Pu the pinnules are slightly shorter than P« but stouter and strongly
carinate dorsally; the first segment is somewhat trapezoidal, the second is enlarged and
about as long as broad, and those following are smaller and somewhat longer than broad.
The distal pinnules arc slightly longer and more slender with the enlargement of the
second segment not quite so strongly marked.

The color "varies from almost white through pale straw color to a light yellowish
brown." Small specimens are the lightest and large specimens the darkest.

Notes. — -The specimens from Albatross station 2354 are of average size.

32 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

One of the specimens from Albatross station 2165 is medium sized with 30 arms
and very spiny. Another is similar but has about 20 arms, IIIBr series being present
on one ray.

The specimen from Albatross station 2169 is similar to that from station 2354.

The specimen from Albatross station 2337 is medium sized or rather small with
the arms 75 mm. long and the cirri X, 40 mm. long. The dorsal spines on the brachials
are remarkably developed.

Two specimens from Albatross station 2342 are of medium size; one has 25 arms
and cirri with 45-50 segments, the other has 30 arms and cirri with 35-40 segments.

Three small specimens from Albatross station 2346 are probably immature; the
arms are 55 mm. long with well developed brachial spines and the cirri are 26 mm. long
with 40-45 segments.

A specimen from Albatross station 2345 is of average development; the arms are
90 mm. long with strongly developed brachial spines and the cirri are XIV, 40.

The specimens from Albatross station 2349 are rather small.

From Albatross station 2336 comes a very large specimen with 30 arms 140 mm.
long; the long dorsal spines are rather poorly developed and die away before the middle
of the arms is reached. The cirri are 50 mm. long with 65-80 segments, none of which
are longer than broad; the longer proximal segments, which are almost as long as broad,
are characteristically constricted centrally. The color is rather dark brown.

Dr. Clemens Hartlaub gave a general account of 21 specimens from Blake stations
155, 220, 231, 232, 249, 259, 269, 290, 292, 297, 298, and 299. The largest number of
specimens came from the stations off St. Vincent. He called attention to the uniformity
of the bottom conditions on which this species occurs — rocks, coarse sand, coarse sand
and rocks, coarse coral sand and broken shells, calcareous stones, broken shells and
coral, and coral and coralline. He gave the following summary of the characters of
the species: The centrodorsal is thick, short-columnar, dorsally sometimes rounded,
sometimes more flattened, with a large bare dorsal pole which has a rough surface
showing small sharp spines and traces of five interradial ridges, which become stronger
on the sides of the centrodorsal, where they separate the five radial pairs of cirrus sockets
from each other. The cirrus sockets are arranged in 10 columns of 3 or 4 each, though
the cirri present in each column are never more than 2.

The cirri are about XV, with up to 70 segments, and reach 40 mm. in length.
They are long with the segments in the proximal half, except for the basal, elongated,
and those in the distal half short. The very uniform short segments ha the distal
half of the cirri bear the usual spines, their dorsal profile being prominently crenulate.

The radials are visible. The IBr: are about as long as the IBr2 and are not incised.
The IBr2 (axillaries) are approximately rhombic and rather short. The IIBr and
IIIBr series are 2. As a rule IIIBr series are developed on the inner branch from each
IIBr series so that each postradiai series bears 6 arms arranged in 1, 2, 2, 1 order.
Occasionally IVBr 2 series are developed.

The ossicles from the IBri onward are laterally free. There is an exception to this,
however, in a specimen from Blake station 249 (Grenada) in which the IBri are in lateral
contact by their lateral edges which, however, are not flattened laterally. Slight
synarthrial tubercles are present. The elements of the division series have the outer
surface concave. There is never any trace of lateral flattening. On all the ossicles of

A MONOGRAPH OF THE EXISTING CRINOIDS 33

the division series there are relatively long, straight, pointed, and scattered spines
which are especially numerous along the edges. Occasionally (as in two specimens
from Montserrat) these are entirely confined to the ambulacral margins of the ossicles.

There are 30 arms about 100 mm. long which even at the base, and especially farther
out, are strongly compressed laterally. The first brachials are somewhat broader than
long and are not entirely in contact interiorly. The second brachials are squarish. The
first and most of the second brachials bear spines resembling those of the elements of
the division series on their proximal and distal edges. The first syzygial pair (composed
of brachials 3+4) is as long as the first and second brachials together. The epizygal
(fourth brachial) has several stronger spines on its distal border of which one is especially
strong. The five following brachials are approximately as long as broad, and those
succeeding are trapezoidal, gradually passing to approximately triangular. The bra-
chials remain triangular until about the middle of the arm when they again become
trapezoidal. The brachials in the proximal third of the arm are rather strongly saddle-
shaped. The five or six brachials following the first syzygial pair have on each side
of the distal edge a small group of minute spines, and a single spine on the dorsal surface
that also stands near the distal edge. These sharp dorsal spines, which are directed
obliquely distally and outwardly, have at first a more central position, but they soon
move to the longer side of the brachials so that they come to alternate in position on
succeeding brachials. The stoutness of the dorsal spines is already considerable on the
seventh brachial, and increases rapidly and markedly; at the same time the form be-
comes like that of a curved pick, strongly compressed laterally. The base of the spines
becomes constantly longer and finally extends for the entire length of the dorsal surface
of the brachials. In the outer half of the arms the stoutness of the spines decreases
again, corresponding to the decrease in size of the brachials

The first syzygy is between brachials 3+4 and the second from between brachials
34+35 to between brachials 39 + 40, or even farther out — between brachials 45+46
in a specimen from Montserrat. Then there is usually an interval of 7 muscular articu-
lations, and the distal intersyzygial interval is 4-6 muscular articulations A specimen
from Blake station 298 (Barbados) has the second syzygy frequently between brachials
21 + 22, and in one arm it is between brachials 15+16.

PI on an outer arm from a IIBr axillary is weak and slender, and of very variable
length, sometimes about 12 mm. long with about 20 segments. P2 is 13 mm. long. P3 is
of about the same length as P2, but more slender. P4 is scarcely half as long, with 9-10
segments. The segments of all these pinnules are rounded and greatly elongated with
the exception of the outermost and the basal which, however, arc somewhat longer
than broad; they bear small spines on their distal ends. The pinnules remain of the
same length up to about P7 or P8, the length of the pinnules following increasing. The
segments of the pinnules meanwhile become thicker and relatively shorter and are no
longer angular. Already on P4 the second segment shows a slight broadening and
elongation on the side toward the centrodorsal. Both these features increase markedly
on the pinnules following and persist far out along the arm. On the later pinnules the
first segment is also broadened, and toward the end of the arms only the first is broad-
ened. The pinnules of the middle arm region are commonly G mm. long with about
13 segments of which the lowest are much broadened while those following are some-
what elongated and taper rapidly. The greatest length of the distal pinnules is 8 mm.

843803 — 50 4

34 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Toward the ends of the arms they become shorter. The segments of the lowest
pinnules have small spines on their distal edges. The relative length of the proximal
pinnules is very variable. On the same specimen P2 is sometimes longer than P,, and
sometimes it is shorter, occasionally very small, and this is true of wholly comparable
arms, as for instance of arms from a IIBr axillary. This inconstancy holds for the
outer as well as for the inner arms. On many arms from a IIBr axillary Hartlaub
found all three of the lowest pinnules of the inner side (P., Pb, and Pe) very small,
though sometimes they are of about the same length as the pinnules of the outer
side (Pi, P2, and P3).

The pinnules have prominent side and covering plates. When viewed from the
ventral side of the pinnule the side plates appear to alternate with each other and to
form a continuous zigzag wall.

The disk is strongly incised and is beset with irregularly distributed spines. Sac-
culi are numerous on the pinnules and very thick and crowded on the arms. The size
of the sacculi is proportionate to that of the underlying ossicles.

The color in alcohol is brownish white, the arm bases sometimes somewhat darker.
The disk is bright brown with a reddish tinge.

Hartlaub wrote that the two specimens from Montserrat in 88 fathoms (Blake
station 155) and two from St. Lucia in 278 fathoms (Investigator) differ so markedly
from the others that they may be regarded as representing a special variety for which
he proposed the name brevispina. According to him the special characters of var.
brevispina are: (1) Almost complete absence of the small sharp spines on the ossicles
of the division series; (2) markedly weak development of the pick-shaped spines on
the brachials; (3) much stronger development of the spines on the segments of the
lower pinnules; (4) more deeply saddle-shaped ossicles of the division series; (5) deeper
yellow-brown color, with a darker shading of the division series ; and (6) more pentag-
onal and longer IBr axillaries.

Regarding a very young specimen of which a figure had been prepared by Car-
penter, Hartlaub said he believed he had found it in the material sent him, although
it bore no label in Carpenter's hand and was much more fragmentary than the figure
showed. The specimen measures 6 mm. from the centrodorsal to the tip of the longest
arm stump. The cirri are broken off.

Carpenter's figure, according to Hartlaub, is not correct in certain details. It
shows hi the middle of the radial a strong longitudinal ridge which is not present;
instead, there are two small spines, one more proximal, the other more distal. A
fairly deep cleft between the centrodorsal and the radials is not once indicated although
in young, as in older, individuals such a cleft is commonly present and is fairly charac-
teristic of the species.

In a very young specimen from Barbados there is a subradial cleft, and the radial
has a swelling on either side. The lateral swellings of two adjacent radials form a
sort of base against which the proximal end of the interradial ridge of the centrodorsal
rests. A similar interradial structure is found also hi fully grown individuals.

Carpenter's figure is further inexact in that the brachials are shown as smooth
whereas hi the specimen spines are developed hi many places. The spinosity hi this
species appears very early, as is shown by other small specimens. On the side opposite
that shown in the figure a IIBr 2 series is developed, so that there are at least 1 1 urine.

A MONOGRAPH OF THE EXISTING CRINOIDS 35

Hartlaub said that after the removal of the cirri the centrodorsal shows five strong
interradial ridges and five weaker midradial ridges. As a result of the presence of
these ten ridges the ventral surface of the centrodorsal is rather decagonal than pen-
tagonal. The radial grooves are approximately triangular, the basal grooves moder-
ately deep and broadened in the middle. The opening of the central cavity shows ten
convex projections.

The dorsal surface of the radial pentagon is approximately pentagonal, with a
well-developed basal star. The rosette and basal bridge are well developed. The
basals almost always show in the middle of the ventral surface a sharp carination.
The dorsal surface of the basal rays shows irregular unevennesses. The peripheral
ends are sometimes reduced, sometimes broad, in basal rays from the same specimen,
these structures appearing to be rather variable even in a single example. Centrally
the basal rays are set off from the rosette part by a weak, necklike connection. The
rosette part shows on the ventral surface two small openings, on the dorsal surface a
single large opening.

The sculpture of the articular faces of the radials, according to Hartlaub, is well
marked and, though minor variations occur, the main features are constant in different
individuals (see Part 2, p. 46, figs. 72, 73, p. 43). A median vertical ridge is present,
through this is short since the distal border has a broad and deep median incision.
It is only slightly raised, very broad, and very deep since the excavations of the joint
surface abut against it hi the form of niches. The muscular fossae arc in general
rather flat and are separated from the somewhat more deeply excavated interarticular
ligament fossae by prominent diagonal ridges. The relatively strong development of
the dorsal ligament fossa is striking. The central canal is situated approximate!}- in
the center of the articular face. At the base of the radials are two lateral knobs directed
dorsally, forming with the corresponding structures of the neighboring radials bases
against which the interradial ridges of the centrodorsal rest. The central cavity, as
viewed ventrally, is bordered by five vertical pairs of laminae, the floors of the mus-
cular fossae, the five pairs being separated by five radial notches. The components
of these pairs are separated by deep interradial clefts. Since the upper ends of the
laminae are curved the circumference of the central cavity has a scalloped appearance.

Carpenter's original description, based upon the specimen in the Paris Museum
collected by Duchaissaing in 1870, was as follows:

Cirri 12-20; long and slender, composed of 40-60 joints, the later ones of which bear dorsal spines.
The rays may fork four times, each subdivision consisting of 2 joints not united by a syzygy. Usually,
however, there are not more than 2 axillaries, the distichal [IIBr] and the palmar [IIIBr], above the
radials [radials and IBr series]; and palmars are frequently only developed upon the inner pair of the 4
secondary arms; so that there are 30 arms in all (as in the Paris specimen), viz., 6 on each ray, in the
following order: 1, 2, 2, 1. Tolerably large, sharp spines are scattered irregularly over the calyx and
arm bases. The ami-joints are triangular in outline, alternating with one another from side to side;
and from near the base of each triangular surface there rises a strong curved spine, which projects
forwards and slightly outwards. On the lower parts of the arms, therefore, there is a double row of
these spines alternating right and left of the median dorsal line; but farther out, as the joints become
more and more compressed laterally, the two rows gradually coalesce into a single median one, the
spines at the same time becoming less and less prominent. The disk bears a fairly complete anam-
bulacral plating, and there is a double row of plates along each edge of the pinnule ambulacra, viz.,
side plates resting on the pinnule joints and supporting the covering plates which overlap one another
alternately from opposite sides. The color varies from almost white through pale straw color to a

36 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

light yellowish brown. The diameter of the disk is 6 or 7 millimeters, and the spread of the arms
about 20 centimeters.

I examined the specimen from Guadeloupe at the Paris Museum in 1910. It is a
rather slender example, of medium size.

Hartlaub pointed out that it is difficult to see why Carpenter made this species,
which has the division series laterally free, the type of his Spinifera group which is
characterized by laterally sharply flattened ("wall-sided") division series. He also
noted that Carpenter did not mention the characteristic remoteness of the second
syzygy, and that he said nothing about the proximal pinnules.

According to Miss Boone the larger specimen from off English Cay, Bahamas, has
an arm length of 74 mm. and cirri 28 mm. long, and the smaller has the arms 72 mm.
and the cirri 28 mm. long.

The specimen from the Snapper Bank has 27 arms which are about 120 mm. long.

The two specimens from Blake station 155 in the Museum of Comparative Zoology
are rather small.

A specimen from Blake station 269 in the Museum of Comparative Zoology has 30
arms.

Dr. H. L. Clark wrote that the Atlantis dredged two small specimens and one
large one with 29 arms nearly 100 mm. long off Matanzas, Cuba, in 190-200 fathoms.

From the specimens that I have been able to examine it would appear that this
species is most abundant and reaches the largest size off the northern coast of Cuba
in the vicinity of Habana. Farther west, toward Yucatan, the size decreases, and
eastward and southward along the Lesser AntiDes the average size is also distinctly
less, specimens from Barbados, St. Vincent, and Grenada all being quite small.

Commensals. — Hartlaub noted that on the specimens from St. Lucia (Blake station
220 and Investigator) there were small barnacles. Barnacles of the genus Scalpellum
are common on the cirri of this species throughout its range (see Part 2, p. 639, and
pi. 53, fig. 1345). A specimen in the Museum of Comparative Zoology from Blake
station 269 carries six of these on its cirri.

Localities, — Bahamas; near English Cay; yacht Pawnee I, April 1925 [Boone,
1928] (1).

Albatross station 2354; northeast of Cozumel Island, off the coast of Yucatan
Gat. 20°59'30" N., long. 86°23'45" W.) ; 238 meters; coral bottom; January 22, 1885
(1 + . U.S.N.M., 34567, 34603).

Albatross station 2165; off Habana, Cuba Gat. 23°10'39" N., long. 82°20'28" W.);
366 meters; coral bottom; May 1, 1884 (2, U.S.N.M. 16901, 16902).

Albatross station 2169; off Habana, Cuba Gat. 23°10'28" N., long. 82°20'27" W.);
143 meters; coral bottom; May 1, 1884 (1, U.S.N.M. 34649).

Albatross station 2337; in the vicinity of Habana, Cuba (lat. 23°10'39" N., long.
82°20'21" W.); 364 meters; coral bottom; January 19, 1885 (1, U.S.N.M., 34568).

Albatross station 2342; in the vicinity of Habana, Cuba Gat. 23°10'39" N., long.
82°20'21" W.); 368 meters; coral bottom; January 19, 1885 (2, U.S.N.M., 34565).

Albatross station 2346; in the vicinity of Habana, Cuba (lat. 23°10'39" N., long.
82°20'21" W.); 366 meters; coral bottom; January 20, 1885 (3, U.S.N.M., 34566).

Albatross station 2345; in the vicinity of Habana, Cuba (lat. 23°10'40" N., long.

A MONOGRAPH OF THE EXISTING CRINOIDS 37

82°20'15" W.); 337 meters; fine gray and white coral; January 20, 1885 (1, U.S.N.M.,
34563).

Albatross station 2349; in the vicinity of Habana, Cuba Oat. 23°10'40" N., long.
82°20'15" W.); 333 meters; coral bottom; January 20, 1885 (4, U.S.N.M., 34564).

Atlantis station 3303; off Playa Baracoa, Habaua Province, Cuba Oat. 23°05' N.,
long. 82°33' W.); 475 meters; March 23, 1939 [H. L. Clark, 1941].

Atlantis station 3465; Bahia de Matanzas, Cuba Oat. 23°09' N., long. 81°27' W.);
320 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3466; Bahia do Malanzas, Cuba (lat. 23°09' N., long. 81°27'30"
W.); 366 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3482; Bahia de Matanzas, Cuba (lat. 23°09' N., long. 81°27'30"
W.); 347 meters; May 11, 1939 [H. L. Clark, 1941].

Albatross station 2336; in the vicinity of Habaua, Cuba Oat. 23°10'48" N., long.
82°18'52" W.); 287 meters; coral bottom; January 19, 1885 (1, U.S.N.M., 34601).

University of Iowa's Bahamas Expedition station 2; about 2.5 miles off Habana,
Cuba; 201 meters [H. L. Clark, 1918] (1, U.S.N.M., E. 4500).

Albatross stations 2319-2350; in the vicinity of Habana, Cuba; 60-510 meters;
January 17-20, 1885 (5, U.S.N.M., 34561, 34562).

Off Habana, Cuba; Albatross, 1885 (1 + , U.S.N.M., 35596, 36186).

Cuba; Albatross (fragments, U.S.N.M., 36186).

Johnson-Smithsonian Expedition; yacht Caroline station 43; southeast of Mona
Island, between Haiti and Puerto Rico (lat. 18°03'45" N., long. 67°48'10" W.);
439-548 meters; February 11, 1933 (1, U.S.N.M., E. 3910).

Off Puerto Rico; Johnson-Smithsonian Expedition (1, U.S.N.M., E. 5258).

Snapper Bank, off the southeastern corner of Puerto Rico; from a cable; Eastern
and Associated Telegraph Company [A. H. Clark, 1929] (1, B. M.).

St. Croix, Virgin Islands [P. H. Carpenter, 1881, as Santa Cruz] (1, C. M.).

Blake station 155; off Montserrat Oat. 16°41'54" N., long. 62°13'24" W.); 161
meters; bottom temperature 20.56° C.; January 16, 1879 [von Graff, 1883, 1884;
Hartlaub, 1912] (2, M. C. Z., 304).

Blake station 157; off Montserrat; 219 meters; no further data [von Graff, 1884],

Guadeloupe; M. Pierre Duchaissaing de Fonbressin, 1870 [P. H. Carpenter, 1881;
A.H.Clark, 1911] (1, P. M.).

Blake station 220; off St. Lucia Oat. 13°50'15" N., long. 61°03'45" W.) ; 212 meters;
rock; bottom temperature 14.72° C.; February 16, 1879 [Hartlaub, 1912] (1, M. C. Z.,
303).

Off St. Lucia; 508 meters; cable repair ship Investigator, Captain Cole [P. H.
Carpenter, 1881; Hartlaub, 1912] (fragments of arms, M. C. Z.).

Blake station 290; off Barbados (lat. 13°11'54" N., long. 59°38'45" W.); 133
meters; coral, sand, and shells; bottom temperature, .21.53° C.; March 9, 1879 [Hart-
laub, 1912].

Blake station 292; off Barbados Oat. 13°13'55" N., long. 59°38'50" W.) ; 102
meters; coral, sand, and broken shells; bottom temperature 23.6° C.; March 9, 1879
[Hartlaub, 1912].

Blake station 297; off Barbados Oat. 13°02'36" N., long. 59°37'45" W.); 225
meters; rock; bottom temperature 13.6° C.; March 10, 1879 [Hartlaub, 1912].

38 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Blake station 298; off Barbados (lat. 13°03'28" N., long. 59°37'40" W.); 220
meters; rock; bottom temperature 16.11° C.; March 10, 1879 [Hartlaub, 1912] (1,
M. C. Z., 65).

Blake station 299; off Barbados (lat. 13°05'00" N., long. 59°39'40" W.); 256
meters; coral and broken shells; bottom temperature 13.6° C.; March 10, 1879 [Hart-
laub, 1912].

Barbados [A. H. Clark, 1913, 1921] (1, B. M.).

Blake station 231; off St. Vincent (lat. 13°12'10" N., long. 61°17'18" W.); 174
meters; sand and broken shells; bottom temperature 16.4° C.; February 20, 1879 [Hart-
laub, 1912].

Blake station 232; off St. Vincent Gat. 13°06'45" N., long. 61°06'55" W.); 160
meters; coral; bottom temperature 16.67° C.; February 21, 1879 [Hartlaub, 1912]
(11, U.S.N.M., 35884; M. C. Z., 116, 302).

Blake station 269; off St. Vincent (lat. 13°07'55" N., long. 61°05'36" W.); 227
meters; coral; bottom temperature 14.17° C.; March 3, 1879 [P. H. Carpenter, 1881;
von Graff, 1883, 1884; Hartlaub, 1912] (14, U.S.N.M., 22456; M. C. Z., 67, 301).

Blake station 259; off Grenada (lat. 12°03'15" N., long. 61°46'25" W.); 291 meters;
sand and ooze; bottom temperature 11.9° C.; February 28, 1879 [Hartlaub, 1912].

Blake station 249; off Grenada (lat. 11°48'15" N., long. 61°48'45" W.) ; 479 meters;
coarse sand; bottom temperature 8.33° C.; February 27, 1879 [Hartlaub, 1912] (3,
M. C. Z., 66).

From Santa Cruz (St. Croix) to Grenada; 147-543 meters [P. H. Carpenter,
1881]. This refers to the specimens collected by the Blake.

Caribbean Islands; 146-543 meters [P. H. Carpenter, 1888]. This refers to the
specimens collected by the Blake.

Geographical range. — Bahamas and Greater and Lesser Antilles westward to Cozu-
mel Island off the coast of Yucatan and southward to Grenada.

Bathymetrical range. — From 102 to 508 (?548) meters; the average of 24 records is
265 meters, but the true average depth is probably considerably less than this.

From the records it would appear that this species occurs in somewhat deeper
water in the Bahamas and Greater Antilles (average of 10 records 300 meters) than
in the Lesser Antilles (average of 14 records 245 meters) but this probably is due to the
fact that most of the specimens from Cuba were collected during intensive work on and
about the so-called "Pentacrinus grounds" off Habana.

This species occurs in water of less depth than would appear from the records, for
the type specimen from Guadeloupe and the specimen in the British Museum from
Barbados were brought up on fishermen's lines.

Thermal range. — From 8.33° to 23.6° C.; the average of 12 records is 15.93° C.

Bottom. — This species inhabits hard bottom, 70 percent of the bottom records being
coral, alone, or in a few cases with broken shells, or broken shells and coarse sand.
Three records show rocky bottom. A single bottom sample showed sand and ooze.

History. — The first known specimen of this species was brought from the Danish
West Indies (now the Virgin Islands) to the Copenhagen Museum where it received
from Prof. Andreas S. Oersted the manuscript name of Alecto serrata, though he never
described it.

A MONOGRAPH OF THE EXISTING CRINOIDS

39

In his preliminary report upon the comatulids collected by the United States Coast
urvey steamer Blake in 1878 and 1879, which was published in 1881 , Dr. Philip Herbert
Carpenter wrote that the two species which from their abundance appear to be especially
characteristic of the Caribbean Islands, ranging from Santa Cruz (St.Croix) to Grenada,
are an Antedon and an Actinometra, both of which had been obtained prior to the Blake
expedition. He said that in 1870 M.Duchaissaing had brought from Guadeloupe to the
Paris Museum a fine specimen of Antedon with 30 very spiny arms. Professor Perrier
having kindly permitted him to examine it and to make a note of its characters, he
readily recognized the species in the Blake collection, and proposed to call it Antedon
spinifera. Carpenter noted that it had been obtained by the Blake at 10 stations in
depths of from 80K to 297 fathoms. It was most abundant at station 269 in 124 fathoms
off St. Vincent, and he said that it was also dredged in 278 fathoms off St. Lucia by the
Investigator. He then described Antedon spinifera in considerable detail. The
Actinometra to which he referred was Neocomatella pulchella (see Part 3, p. 124).
Carpenter's mention of Santa Cruz was based upon Professor Oersted's specimen at
Copenhagen which he had examined, although he nowhere referred to it.

In 1882 Prof. Francis Jeffrey Bell proposed a specific formula for this species,
which was criticized and emended by Carpenter early in 1883.

Prof. Ludwig von Graff in 1883 described Myzostoma agassizii (see Part 2, p. 664)
including among the localities Blake stations 155 and 269 where he said the host was
apparently Antedon spinifera.

In his report upon the stalked crinoids of the Challenger expedition published in
1884 Carpenter called attention to the fact that in certain recent pentacrinites, as
Endoxocrinus parrae ("mulleri"), Diplocrinus maclearanus, D. alternicirrus , and
Annacrinus wyvillethomsoni secondary and tertiary axillaries are limited to the outer
arms of each successive pair whereas Stylometra spinifera often shows exactly the
reverse condition to this, the IIIBr axillaries being frequently developed only on the
inner pair of the four secondary arms.

In 1884 Professor von Graff described Myzostomum pictum from Blake station 157,
the host being probable Stylometra spinifera (see Part 2, p. 663), and gave this species
as the probable host of Alzyostomum agassizii from Blake stations 155 and 269.

In 1884 William Neale Lockington gave an account of the occurrence of this
species and Actinometra (Neocomatella) pulchella in the Caribbean region taken from
the notes published by Carpenter in 1881.

In the Challenger report on the comatulids published in 1888 this species was not
treated in detail as it was not secured by the Challenger, but various notes on it were
given. Carpenter pointed out that it not infrequently has exactly 30 arms owing to the
presence of IIIBr axillaries on the inner pair of every four secondary arms, and that
occasionally IVBr series are present. He made it the type of the Spinifera group the
members of which he characterized as "Bidistichate species with the radial axillaries
[IBr3] and some of the following joints more or less wall-sided, and a well-marked
ambulacral skeleton on the pinnules." He compared Antedon spinifera in detail with
his new species Antedon (Stenometra) quinquecostata, and in much less detail with A,
(Stiremetra) lusitanica. The range of Antedon spinifera was given as the Caribbean
Islands in 80-297 fathoms.

40 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Alexander Agassiz in 1888 published a resume of Carpenter's original account of
this species, accompanied by a very characteristic figure.

In 1889 Carpenter compared the arm division of Antedon elegans (= Zygometra
comata), in which IIIBr series frequently occur on the inner branches from the IIBr
axillaries, to that of this species.

Wilhelm Minckert hi 1905 noted that in this species single hypozygals or epizygals
in the proximal portion of the arms are not smaller than the other brachials. His
notes were based upon specimens from the Blake collection.

In 1907 I referred this species to my new genus Thalassometra, and later in the
same year I compared the brachial spines of Thalassometra spinifera with those of a
new species, Thalassometra hawaiiensis. In 1909 I established the new genus Stylo-
metra for this species and "an undescribed form from the Caribbean Sea." The latter
was described by Hartlaub in 1912 as Antedon spinifera var. brevispina. During a
visit to Paris in 1910 I examined the specimen brought back by M. Duchassaing from
Guadeloupe which hi 1911 I said was "Une exemplaire de moyenne grandeur, un peu
mince."

In his report published hi 1912 on the comatulids collected by the United States
Coast Survey Steamer Blake in 1878 and 1879 Dr. Clemens Hartlaub recorded Antedon
spinifera from 12 Blake stations and also recorded specimens that had been taken from
a cable raised from 278 fathoms off St. Lucia by the cable repair ship Investigator,
Capt. H. Cole. Dr. Hartlaub gave a very detailed and most excellent account of this
species, with many excellent figures. He described a new form, Antedon spinifera var.
brevispina, which was the same as my "undescribed form" mentioned in 1909. The
Blake collection had originally been sent to Dr. P. H. Carpenter for report, and was
turned over to Hartlaub after Carpenter's death. Together with the specimens there
were numerous drawings that had been prepared under Carpenter's direction. These
were largely unidentified. Such as could be identified from specimens in the Blake
collection or from Albatross specimens in the National Museum were retained and the
others discarded and original drawings prepared under Hartlaub's direction substi-
tuted.

In 1913 I recorded a specimen from Barbados that I had examined hi the British
Museum in 1910. In my memoir on the unstalked crinoids of the Siboga expedition
published hi 1918 Stylometra spinifera was included and its synonymy was given.

In his report on the Crinoidea and Echinoidea collected by the Bahama Expedi-
tion of the University of Iowa in 1893 which was published in 1918 Dr. Hubert Lyman
Clark recorded a single specimen of Stylometra spinijera from station 2. He said "A
single fine specimen of this beautiful species is all that the present collection contains.
Unfortunately the cirri are all broken, but enough is left of one to reveal the character-
istic features."

In my memoir on the unstalked crinoids collected by the Siboga Expedition pub-
lished hi 1918 I inserted the genus Stylometra in a key to the genera of the Thalasso-
metrinae, giving the range as from Yucatan to Grenada, and gave the synonymy of
S. spinifera. In a paper on the crinoids and brittle-stars of the Barbados-Antigua
Expedition of the University of Iowa in 1918 which was published on March 15, 1921,
I summarized all the records for this species hi the vicinity of Barbados. In the same
year in another paper I republished the figure given in Part 1 as figure 35 on page 73

A MONOGRAPH OF THE EXISTING CRINOIDS 41

showing the progressive individualization of the hypozygals of the syzygies distally
along the arms. In my memoir on the crinoids of the Danish Ingolf Expedition pub-
lished in 1923 I gave the range of Stylometra spinifera as "From Yucatan to northern
Cuba and southward to Barbados and Grenada; definitely known from 102-508 meters:
but it occurs in lesser depths."

In 1924 Prof. Torsten Gislen described the syzygies in a specimen with the arms
about 90 mm. long. He did not give the locality of the specimen; it was one of those
dredged by the Albatross in the vicinity of Habana, Cuba (stations 2319-2350).

In 1928 Miss Pearl Lee Boone recorded " two fine specimens" of Stylometra spinijera
from off English Cay, Bahamas, in 190 fathoms, where they had been dredged by
Harry Payne Bingham on his yacht Pawnee I. In the introduction to the paper she
said that the crinoids secured by the expedition arc "represented by several specimens
of one species, Stylometra spinifera," and gave notes on the commensalism of the
species. She said "Interesting notes were obtained of commensalism between this
crinoid and three species of Crustacea, an aiiomuran, Uroptychus rugosus Milne Ed-
wards, an isopod, Arcturus pawneeanus Boonc, and a pedunculate barnacle, Scalpellum
rodstomi Boone. A species of ophiuran, Ophiothrix angulata Say, was also found en-
twined in the arms of one of these specimens." Barnacles of the genus Scalpellum are
commonly found attached to the cirri of this species throughout its range (see Part 2,
p. 639, pi. 53, fig. 1345). The two other crustaceans and the ophiuran mentioned are
not commensal with criuoids, though they occur in the same areas; they were simply
crushed in among the arms of the crinoids during capture.

In 1929 I recorded a specimen in the British Museum that was taken from a
cable crossing the Snapper Bank off the southeast corner of Puerto Rico by a cable
repair ship of the Eastern and Associated Telegraph Co.

In 1943 Prof. Torsten Gislen gave further notes on this species.

In 1941 Dr. Hubert Lyman Clark recorded 10 specimens from Atlantis station
3303, off Playa Baracoa, Cuba, in 260 fathoms, and tliree from stations 3465, 3466,
and 3482, off Bahia de Matanzas in 190-200 fathoms, giving notes on the latter.

Genus COSMIOMETRA A. H. Clark

Antedon (part) HARTLATJB, Nachr. Ges. Gottingen, May 1890, pp. 169, 173, and following authors

Thalassomctra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.

Stenometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15.

Cosmiometra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 16 (diagnosis; genotype
Tkalassometra komachi A. H. Clark, 1908); Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10 (repre-
sented in the West Indies by Stylo-metro) , p. 13 (common to southeastern Africa and the Bay of
Bengal, but not occurring in the Arabian Sea); Crinoids of the Indian Ocean, 1912, p. 10 (2
species in the Hawaiian Islands), p. 12 (represented in the southeast African region), p. 13 (cor-
responds to the West Indian Stylometra), p. 2-1 (next to Thalassometra the most widely spread
genus of the family; range), p. 59 (in key), p. 214 (original reference; genotype); Internal. Rev.
gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4 and following (represents Stylometra in the Indo-
Pacific; range) ; Die Crinoiden der Antarktis, 1915, p. 125 (certain species of this genus show the
characteristic features of Anlhometra adriani), p. 181 (range; represented in the Atlantic by
Stylometra); Unstalkcd crinoids of the Stftoja-Exped., 1918, p. 148 (in key; range), p. 153 (key
to the included species). — GISL^N, Kungl. Fysiograf. Siillsk. Hand!., new ser., vol. 45, No. 11,
1934, p. 20.

42 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Diagnosis. — A genus of Thalassometridae in which the brachials beyond the basal
are laterally compressed and carinate; the divisions series, which are all 2, vary from
strongly rounded to more or less flattened dorsally with the dorsal surface of the com-
ponent ossicles plain and unmodified, or with the edges everted or bordered with fine
spines or bands of fine spines; and the brachial carination is not produced into long
overlapping spines. The 20-30 arms are 70-130 mm. long, and the slender cirri are
25-50 mm. long with 29-74 segments.

Geographical range. — From southern Japan and the Hawaiian Islands to south-
eastern Australia (Bass Strait) and westward to Ceylon, the Maldive Islands, and
Saya de Malha.

Bathymetrical range. — From 183 (?128) to 730 (?740) meters.

Thermal range.— From 5.44° to 23.2° C.

Remarks. — The genus Cosmiometra, of which Stylometra is the Atlantic representa-
tive, is related to Parametra and Lissometra, from which, however, it appears to be
quite distinct. When fully developed the species are easily recognized by their long
and slender cirri with numerous segments, combined with the 20 or more arms, all the
division series being 2, and the arms being laterally compressed and carinate in their
middle and outer portions.

The 10 species of Cosmiometra fall into two groups. In one of these groups the
arms are probably 30 in number in fully developed individuals, one IIBr 2 series being
present on each of the two outer sides of each postradial series. This group is known
only from the Hawaiian Islands (delicata) and from Ceylon and the Maldive Islands
(leilae). The two species of this group are probably not closely related to each other,
but instead are of independent origin from the stem type of the other group. In the
other group there are normally 20 arms, all the IIBr series being present. In spite
of considerable variation in detail from one species to another, the species of this group
appear to be quite homogeneous, and, except in the number of arms, they do not differ
from the species of the first group. In the Atlantic genus Stylometra the single species,
S. spinijera, may have either 20 or 30 arms, but this does not appear to be the case
in any species of Cosmiometra.

History. — The first known species of this genus (com/era) was described as an
Antedon by Dr. Clemens Hartlaub in 1890, and the second (woodmasoni) was also
referred to Antedon by Prof. F. Jeffrey Bell in 1893. To these I added Antedon aster
in 1907, later in the same year transferring them all to my new genus Thalassometra.
In 1908 I added Thalassometra delicata, Th. crassicirra, and Th. komachi.

On the establishment of the genus Cosmiometra, with the genotype Thalassometra
komachi A. H. Clark, 1908 (= Antedon aster A. H. Clark, 1907), I included in it crassi-
cirra, delicata, komachi, and woodmasoni. Later in 1909 conifera was recognized as a
member of this genus. In 1915 aster was redetermined as the young of komachi, the
latter name therefore falling into the synonymy of the former. Since 1915 the status of
the genus Cosmiometra has remained unchanged.

In the key to the species of the genus Cosmiometra published ha 1918m my memoir
on the unstalked crinoids of the Siboga expedition there appears the specific name
koehleri, with the locality "St. Vincent, West Indies, 158 meters." This supposed new
species, which was never formally described, proved to be based upon a specimen of
Horaeometra duplex.

A MONOGRAPH OF THE EXISTING CRINOIDS 43

KEY TO THE SPECIES IN THE GENUS COSMIOMETRA

a1. Arms 23-28 in number, the IIIBr series always on the outer side of the IIBr series; cirri with

31-40 segments, 30-35 mm. long; arms 90-110 mm. long.

ft1. Cirri in 15 columns on the cenlrodorsal; transition segment about the eighth; stout; carination
of the brachials high, narrow, and conspicuous (from south of Ceylon to the Maldive Islands;

199-241 meters) leilae (p. 43)

b1. Cirri in 10 columns on the centrodorsal; transition segment about the sixteenth; slender; carina-

tioii of the brachials low and inconspicuous (Hawaiian Islands; 583 meters) delicata (p. 46)

a*. Arms 20 (or slightly less) in number; no IIIBr series.
61. Longest cirri with more than 50 segments.

e1. Elements of the division series and lower brachials with the lateral portions more or less ex-
tensively roughened or finely spinous.

dl. Cirri with 68-74 segments, half as long as the arms or somewhat longer; cirri 45-50
mm. long, arms about 90 mm. long (Bass Strait, between Australia and Tasmania;

128-183 meters) dasybrachia (p. 47)

d1. Cirri with less than 65 (usually 40-55) segments, less than half as long as the arms; arms

100-130 mm. in length.

e1. Edges of the elements of the division series and first two brachials everted and roughened;
cirri arranged in 15 closely crowded columns on the centrodorsal (Sagami Bay, Japan;

183-730 [7740] meters) aster (p. 49)

e'. All but the median third of the dorsal surface of the elements of the division series and
first two brachials finely spinous or tubercular; cirri arranged in 10 definite columns
2 in each radial area, on a conical centrodorsal (Philippines to Celebes and the Kei

Islands; 245-621 meters) philippinensis (p. 52)

c'. Elements of the division series and lower brachials with the lateral borders and the proximal

and distal edges smooth, without spines.

d1. Cirri with about 70 segments, slightly over half as long as the arms, arranged in 10
columns on the centrodorsal; cirri 45 mm. long, arms about 70 mm. long (southern

Japan) „ conifera (p. 56)

d1. Cirri with 50-54 segments, about one-third of the arm length, irregularly arranged in
from one to three columns in each radial area of the centrodorsal; cirri 45 mm. long,

arms 130 mm. long (Hawaiian Islands; 249 meters) crassicirra (p. 58)

V. Cirri with not more than 41 segments.

c1. Carination of the division series and first two brachials broad and low; outer brachials
very strongly overlapping and broadly carinate; cirri slender (Saya de Malha; 247

meters) gardineri (p. 63)

e*. Carination of the division series and first two brachials narrow and higher; outer brachials

moderately overlapping and narrowly carinate; cirri stouter.
d1. Division series and first two brachials with the lateral edges not produced (Sahul

Bank) — — woodmasoni (p. 60)

d1. Division series and first two brachials with the lateral edges produced and slightly
everted, broadly scalloped or bearing two or three blunt tubercles (off southwestern
Mindanao; 292-365 meters).-- iole (p. 61)

COSMIOMETRA LEILAE A. H. Clark

PLATE 5, FIGURE 17; PLATE 6, FIGURE 23

Cosmiometra leilae A. H. CLARK, Rec. Indian Mus., vol. 34, pt. 4, 1932, p. 551 (listed), p. 565 (Investi-
gator station 465; description; comparisons), pi. 20, figs. 18-19; John Murray Exped. 1933-34,
Sci. Reports, vol. 4, No. 4, 1936 (Jan. 1937), p. 87 (listed), p. 92 (Mabahi.t station 157; notes;
range), pp. 101, 103.

Diagnostic features. — This is a stout and robust species with 23-28 arms; and the
cirri, which are relatively stout and rather short and have the transition segment at
about the eighth, are arranged in 15 columns on the large ccntrodorsal. The arms are
90-100+ mm. long, and the cirri are 30-35 mm. long with 31—10 segments.

44 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Description. — The centrodorsal is thick discoidal, about 4 mm. in diameter at the
base and 1.5 mm. high, with the broad rugose dorsal pole about 3 mm. in diameter.
The cirrus sockets are arranged in 15 crowded columns of one or two each, there being
three columns in each radial area; but rarely the median column is absent, leaving two
lateral columns separated by a bare slightly depressed space as broad as a column,
or the central column may consist of a single more or less undeveloped cirrus. The
radial areas on the centrodorsal are not usually differentiated, but in rare cases there
is a narrow sharp ridge that runs down from the ends of the basal rays.

The cirri are XXV, 31-40 (apparently usually about 35), up to 33 mm. in
length. The first segment is three or four times as broad as long or even shorter, the
second is about twice as broad as the greatest (ventral) length, the third is about half
again as broad as long, the fourth varies from slightly broader than long to about one-
third a.gain as long as broad, and those following increase in length to the eighth, a transi-
tion segment, which is three tunes as long as the median width. The succeeding segments
rapidly decrease in length, the eleventh or twelfth being about as long as broad and
the seventeenth and following about half again as broad as long, or sometimes slightly
longer. The central portion of the distal dorsal edge of the transition (eighth) segment
is slightly produced; on the segments following this is raised into an abrupt high process
arising from the end of the second third of the dorsal surface of the segment with,
when viewed along the axis of the cirrus, a rounded or more or less lobate distal end.
Distally this process gradually narrows and at the same time arises from more and more
of the dorsal surface of the segments, becoming on the short outer segments a high and
conspicuous dorsal spine with a strongly rounded, but not carinate, dorsal crest, and
a roundedly blunted tip. The opposing spine is small, smaller than the dorsal spine
on the preceding segment, and blunt; it is terminally situated. The terminal claw is
longer than the penultimate segment, rather slender, and moderately and evenly
curved.

The ends of the basal rays are prominent in the angles of the calyx as rather small
tubercles between the apposed anterolateral angles of the radials and the run of the
centrodorsal.

The radials are short, strongly curved, with the dorsal surface depressed within the
rim of the centrodorsal, especially laterally, making the ends of the basal rays conspic-
uous. The IBri are very short, about six times as broad as the median length, and
are in lateral contact. The midradial line bears a rather high median carination.
The auterolateral angles may bear single tubercles or short blunt spines. The IBr2
(axillaries) are very short, about three times as broad as long, and are rhombic with
the lateral angles slightly truncated. The entire median line is occupied by a rather
high narrow carination, and the edges are slightly everted and produced, most so on the
proximal side. Prominent water pores are present beneath the apposed lateral angles
of the axillaries. The IIBr series are 2, resembling the IBr series; but the component
elements are proportionately longer and the axillaries have much more broadly trun-
cated lateral angles. Rather conspicuous water pores are present on both sides of the
IIBr series. The IIIBr series are 2, always externally developed, and resemble the
IIBr series. The outer side of the IIIBr axillaries is about three times as long as the
inner, the latter being broadly cut away for the formation of the water pore.

A MONOGRAPH OF THE EXISTING CRINOIDS 45

The 24-26 arms are probably over 100 mm. long. The first two brachials are prom-
inently carinate, like the elements of the division series. Their borders are practi-
cally unmodified, or are very slightly and rather broadly thickened. There is a
prominent water pore between the adjacent first two brachials on each arm pair,
formed chiefly by the cutting away of the proximal inner angle of the second brachials.
A low but prominent median carination, abruptly set off from the dorsal surface of the
brachials, runs along the arms to the tip.

PI is slender and not greatly stiffened, 10 mm. long with 17 segments. The
first segment is about as long as broad, the second is slightly longer than broad, the
third is nearly half again as long as broad, and those following slowly and gradually
increase in length so that the fourteenth is twice as long as broad and the sixteenth
is about three tunes as long as broad. The distal ends of the segments are very slightly
prominent, though not everted or otherwise modified, and the distal angles on the side
toward the arm tip are slightly produced, overlapping the base of the segment following.

P2 is S mm. long with 15 segments and resembles PI. P3 is 7 mm. long with 12
segments and resembles P2. P4 is 5 mm. long with 12 segments.

The lower pinnules are all about equally stout basally, and all taper slowly and
evenly to the tip.

Notes. — In one of the specimens dredged by the Mabahiss the 23 arms are 95-100
mm. long. The cirri are XVIII, 36-39, 30-35 mm. long; the transition segment is
usually the ninth, sometimes the tenth. The division series resemble those of the two
original specimens from south of Ceylon, but the elements of the IBr series are often
somewhat rugose laterally, with the distal border of the IBri, and also of the IIBri,
coarsely scalloped laterally.

Another individual has 28 arms 90 mm. long. The division series have a slightly
irregular surface.

In an example with 24 arms the dorsal surface of the division series is scarcely
modified.

Other specimens have 25, 24, 23, 23, 20, and 15 arms, the two last being small.
There are four additional examples.

Color in life. — A note made at the time of capture of the Mabahiss specimens de-
scribes the color, on the basis of Ridgway's "Color Standards and Color Nomenclature,"
as "orange with the aboral surface white."

Remarks. — Cosmiometra leilae appears to be most closely related to C. delicata from
the Hawaiian Islands, but it is a much stouter species with a much broader and lower
centrodorsal on which the cirri are arranged in 15 instead of in 10 columns, the transition
segment in the cirri is the eighth instead of the sixteenth, and the carination of the
brachials is higher, narrower, and more conspicuous.

Localities.— Investigator station 465; south of Ceylon (lat. 5°56' N., long. 81°22' E.) ;
199-241 meters; April 22, 1912 [A. II. Clark, 1932] (2, U.S.N.M., E. 3271; I. M.).

Mabahiss station 157; Maldive area (lat. 4°43'48" N., long. 72°55'24" E. to lat.
4°44'00" N., long. 72°54'18" E.); 229 meters; April 6, 1934 [A. II. Clark, 1937] (13,
B. M.; Cairo Mus.).

History. — Cosmiometra leilae. was described in 1932 from two specimens that had
been dredged in 1912 by the Royal Indian Marine Survey steamer Investigator at
station 465, south of Ceylon. In January 1937, 13 additional specimens were recorded

46 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

from the John Murray Expedition to the Indian Ocean, 1933-34, that had been secured
by His Egyptian Majesty's steamer Mabahiss at station 157 in the Maldive region.

COSMIOMETRA DELICATA (A. H. Clark

PLATE 3, FIGURE 9
[See also vol. 1, pt. 1, fig. 367, p. 297; pt. 2, fig. 214, p. 157.1

Thalassomeira delicata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214 (in key), p. 225
(description; Albatross, station 3963).

Cosmiomelra delicata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 17 (listed); Crinoids
of the Indian Ocean, 1912, p. 215 (synonymy; locality) ; Unstalked crinoids of the Siboga-Exped.,
1918, p. 153 (in key; range), p. 154 (references) ; Rec. Indian Mus., vol. 34, pt. 4, December 1932,
p. 566 (compared with C. leilae). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45,
No. 11, 1934, p. 25. — A. H. CLARK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (Albatrost
station 3963) , p. 97 (station data) .

Diagnostic features. — A slender species with 28 arms; the cirri, which are slender
and rather short and have the transition segment at about the sixteenth, are arranged
in 10 definite columns on a rather small rounded conical centrodorsal. The arms are
110 mm. in length, and the cirri are 30-35 mm. long with 40 segments.

Description. — The centrodorsal is rounded conical, rather small. The cirrus sockets
are arranged in 10 columns, one, more rarely two, to a column.

The cirri are XIII, 40, from 30 mm. to 35 mm. long. The first 2 segments are
short, the third is not quite so long as broad, and the fourth is rather longer than broad.
The following segments to between the tenth and fifteenth are about half again as long
as broad. The transition segment falls between the tenth and fifteenth, but is usually
nearer the latter. The first segment after the transition segment is rather longer than
broad and those following gradually decrease in length, the terminal being about twice
as broad as long. After the transition segment the dorsal distal edge of the segments
projects in the form of a sharp transverse ridge which appears as a spine in lateral
view. The opposing spine in lateral view is triangular and blunt, and does not reach
one quarter the width of the penultimate segment in height. The terminal claw is
somewhat longer than the penultimate segment, rather stout, and only moderately
curved.

The disk is thickly plated along the ambulacral grooves, and bears scattered
calcareous granules in the interambulacral areas. The brachial ambulacra are rather
scantily plated, but side and covering plates are well developed on the pinnules.
Sacculi are abundant on the pinnules, but small.

The ends of the basal rays are visible as tubercles hi the interradial angles of the
calyx.

The radials are concealed by the centrodorsal. The IBri are very short, bandlike,
with the borders prominent and with a blunt median keel. The IBrz (axillaries) are
rhombic, about twice as broad as long, with rather prominent borders and a strong
rounded median keel. The IIBr and IIIBr series are 2, the latter developed exteriorly
in 2, 1, 1, 2 order; both resemble the IBr series. The division series and the first 12
or 15 brachials are sharply flattened laterally.

The 28 arms (in the type) are 110 mm. in length. The first 9 brachials are oblong
or slightly wedge-shaped, broader than long, those following becoming triangular or

A MONOGRAPH OF THE EXISTING CRINOIDS 47

very obliquely wedge-shaped, about as long as broad, and distally wedge-shaped again
and elongate. Except for the few more-or-less oblong brachials at the base of the arms
all the brachials have strongly produced and finely serrate distal edges which overlap
the bases of those succeeding. This overlapping does not involve the entire distal
edges of the segments, but only a comparatively small central portion, so that in a lateral
view the appearance is given of overlapping spines.

Syzygies occur between brachials 3 + 4, again about brachials 16+17, and distally
at intervals of usually 4 muscular articulations.

P! is comparatively slender, though much longer and somewhat stouter than Pa,
tapering evenly from the base to the tip, 7 mm. long with 16 segments of which the
basal 6 are about as long as broad and those following gradually become elongated.
P2 is 4 mm. long, more slender than P,, with 11 segments of which the first 2 are about
as long as broad and the remainder are longer than broad. The following pinnules
decrease in length to the fifth or sixth, which is 3 mm. long, then gradually increase to
9 mm. distally.

The color in alcohol is brownish yellow, with the cirri somewhat lighter.

Locality. — Albatross station 3963; Laysan Island Light, Hawaiian Islands, bearing
N. 56°30' E., 6.6 miles distant; 583 meters; bottom temperature 23.2 C.; white sand
and broken shells; May 22, 1902 [A. H. Clark, 1908, 1909, 1912, 1918, 1932, 1949;
Gisl6n, 1934] (2, U.S.N.M., 22690 [type], 35592).

History. — This species was described under the name of Thalassometra delicata in
1908 from two specimens from Albatross station 3963. It was removed to the new
genus Cosmiometra in 1909. The two original specimens are still the only ones known.

COSMIOMETBA DASVBRACHIA H. L. Clark

Cotmiometra daiybrachia H. L. CLARK, Biol. Res. Fishing Exper. F. I. S. Endeavour, 1909-14, vol. 4,
part 1, 1916, p. 24 (detailed description; east of Flinders Island, Bass Strait, 70-100 fathoms),
pi. 4, fig. 2. — A. H. CLARK, Proc. Biol. Soc. Washington, vol. 31, 1918, p. 42 (listed from
Tasmania).

Diagnostic features. — A rather slender species with 20 arms; the cirri, which are
arranged in 10 definite columns on a moderate sized rounded conical centrodorsal, are
slender and very long, somewhat more than half the length of the arms, with 68-74
segments. The arms are about 90 mm. long, and the cirri are 45-50 mm. long.

Description. — The centrodorsal is markedly conical, scarcely 5 mm. in diameter
at the base and about 4 mm. high. The cirrus sockets are arranged in 10 columns of
3 or 4 each (about 35 altogether), the columns separated in the midradial line by a
rather broad area with a finely roughened surface.

The cirri are about XXXV, 68-74, from 45 to 50 mm. long. The fifth or sixth
segment is the longest, much longer than broad, and all the segments but the proximal
15 have the distal dorsal edge produced into what looks like a sharp spine when seen
from the side. The distal segments, including this dorsal spine, are twice as broad as
long.

The radials are completely concealed except for the small distolateral corner, which
is visible in the interradial angles of the calyx. The IBr, are cresccntic with the proxi-
mal margin strongly convex and the distal correspondingly concave; excepting only the
distal median portion, the whole surface is rough and spinulose, especially the lateral
margins. The IBr2 (axillaries) are rhomboidal with the anterior margins slightly con-

48 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

cave. All the margins are finely serrulate and the lateral surfaces are rough and spinu-
lose. The synarthrial tubercle is smooth and rounded, low but distinct. The IIBr
series are 2, very similar to the IBr series; but the lateral spinulose surfaces are much
less marked, especially on the axillary, and are nearly wanting on the inner side. The
division series and first two brachials have strongly flattened sides. The division
series are in closely appressed contact, but the lower brachials are much less so and
probably in life hardly touch.

The 20 arms are about 90 mm. long. The first two brachials are similar to the
elements of the IIBr series but are relatively much longer and narrower and have no
spinulose lateral areas, though the lateral margins are very serrulate and rough. The
third-tenth brachials are quadrilateral, the following brachials becoming triangular,
the distolateral angle being more and more prominent. Beyond the middle of the arm
the brachials become quadrilateral again and nearly as long as broad. Proximally
both proximal and distal margins are everted and rough, but beyond the twelfth to
fourteenth brachial only the distal margin is conspicuous; even near the tip of the arm,
however, the distal margin is not very flaring and it never overlaps the segment fol-
lowing. Beginning at the thirty-fifth brachial, or thereabouts, the distal dorsal surface
of each segment is rough with minute spines, and these soon cover the whole median
area of the arm; near the arm tip this area is a very narrow band.

The first syzygy is between brachials 3 + 4. In eleven arms of one specimen, but
in only one arm of the holotype, the second syzygy is between brachials 5 + 6, and the
third is somewhere in the region between the eighteenth and twenty-seventh brachials.
In the other arms the second syzygy is generally not until after the twentieth brachial.
The distal intersyzygial interval is at first 6-8 muscular articulations, but near the tip
of the arm it decreases to 4 or 5.

P! is about 11 mm. long with 25 smooth segments of which the six basal are much
broader than long, somewhat axe-head shaped, and much flattened dorsally, and the
remainder are longer than broad, or at least as long as broad, the eighth being the
longest. P2 is similar but only 10 mm. long with only 22 segments. P3 is similar, but
a little shorter. P4 to P]0 are more prismatic, only 5-6 mm. long, with 12-14 segments
which have the distal margins, and a sharp dorsal keel, finely serrulate. The remaining
pinnules are similar but becoming much more slender, longer (8-10 mm.), and with
more segments (17-18); the sharp serrate dorsal keel is well marked.

The color in alcohol is yellowish brown; when dry the shade is much lighter.

Notes. — In a cotype which Dr. Clark very kindly permitted me to examine the long-
est cirrus is 50 mm. long with 74 segments of which the seventh is a transition segment;
the longest segments are half again as long as broad. The crest of the dorsal cirrus
spines is broad, on the average occupying about the median third of the segments in
dorsal view. In lateral view the distal (vertical) edge of the spines is finely serrate,
most pronouncedly so in the outer third of the cirri.

The outer (lateral) thirds of the ossicles of the IBr series and IIBr series appear
spongy; there are a few small spicules on the adjoining edges of the ossicles of the IIBr
series.

The earlier brachials have the borders thickened and rather abruptly everted,
though not produced. As the brachials become triangular small spines are developed
along the distal border which gradually increase in size, especially those in the middle

A MONOGRAPH OF THE EXISTING CRENOIDS 49

of the edge from which serrate ridges gradually extend themselves proximally until
they completely span the brachial, so that the brachials in the outer half of the arm
have a median longitudinal band of fine spines.

Locality. — East of Flinders Island, Bass Strait; 128-183 meters; Endeavour, De-
cember 4, 1913 [H. L. Clark, 1916; A. H. Clark, 1918 (Tasmania)] (2, M. C. Z., 717;
Australian Mus.).

History. — This species was described in 1916 by Dr. Hubert Lyman Clark from
two specimens that had been dredged by the Australian Fisheries Investigation ship
Endeavour east of Flinders Island in 70-100 fathoms on December 4, 1913. Dr. Clark
said that while this species resembles both C. komachi and C. helene in the general
character of the arms, the much more numerous cirrus segments, the longer pinnules,
and the markedly conical centrodorsal seem to prove that it is quite distinct. He
remarked that the genus was not known previously from Australian waters.

In 1918 I listed this species as one of the crinoids known from Tasmanian seas.

COSMIOMETRA ASTER (A. H. Clark)

PLATE 6, FIGURE 21
[See also vol. 1, pt. 2, fig. 215, p. 159.]

Antedon aster A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 145 (description; Albatross
station 5088).

Thalassometra aster A. H. CLARK, Smithsonian Misc. Coll. vol. 50, pt. 3, 1907, p. 360 (listed) ; Proc.
U. S. Nat. Mus., vol. 34, 1908, p. 310 (Sagami Bay) ; Amer. Nat., vol. 42, No. 500, 1908, p. 542
(belongs to a group characteristic of the oceanic area) ; Geogr. Journ., vol. 32, No. 6, 1908, p. 603
(same); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed); Crinoids of the Indian Ocean,
1912, p. 206 (synonymy; locality).

Thalassometra komachi A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 311 (description; Mi*aki),
p. 540 (listed); Unstalked crinoids of the Siboga-Exped., 1918, p. 155 (identity with [Cosmiometra]
aster) .

Cosmiomelra komachi A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 17 (listed); Proc.
U. S. Nat. Mus., vol, 39, 1911, p. 549 (compared with C. philippinensis) ; Zool. Anz., vol. 39,
No. 11/12, 1912, p. 428 (arms compared with those of C. helene); Crinoids of the Indian Ocean,
1912, p. 214 (locality). — H. L. CLARK, Biol. Res. Fishing Exper. F. I. S. Endeavour, 1909-14, vol.
4, pt. 1, 1916, p. 26 (comparison with C. dasybrachia) .

Cosmiometra aster A. H. CLARK, Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern
Japanese species; range and its significance) ; Unstalked crinoids of the Si'boffa-Exped., 1918, p. 154
(in key; range), p. 155 (synonymy).— GISLEN-, Zool. Bidrag Uppsala, vol. 9, 1924, fig. 176, p. 98
(articulation of a distal pinnule); Vidcnsk. Medd. Dansk naturh. Foren. K0benhavn, vol. 83,
1927, p. 3 (stations 15, 25; 180-720 meters), p. 41 (stations 15,25; notes), pp. 68, 69 (listed),
figs. 36, 37, p. 44; Kungl. Fysiogr. Pallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.

Diagnostic features. — A moderately slender species with 20 arms; the cirri, which
are arranged roughly in 15 closely crowded columns on the truncated conical or short
columnar centrodorsal, are nearly half as long as the arms; and the elements of the
division scries and first two brachials have the edges.all around everted and roughened,
the dorsal surface otherwise smooth. The arms are 125 mm. long and the cirri are
25-40 mm. long with 40-55 segments.

Description. — The centrodorsal is bluntly conical or short columnar with the cirrus
sockets arranged roughly in three closely crowded columns in each radial area, or 15
closely crowded columns, with two cirrus sockets to a column. The bare polar area is
granulose.

50 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XXV, 40-55, from 25 to 40 mm. long. They are basally slender and
rounded, becoming much compressed laterally and broad distally. The first four or
five segments are about twice as broad as long, the next is about as long as broad, and
the following, a transition segment, is about twice as long as its proximal width,
decreasing in width distally, with the surface dull and dark like that of the segments
preceding in the proximal two-thirds, and light and highly polished in the distal third.
The cirri decrease in width at this point. The segments following the transition
segment are about as long as broad, the first being usually longer than broad, gradually
becoming shorter, and very short distally. At about the fourth segment beyond the
transition segment the distal dorsal edge begins to project, soon becoming a deep
dorsal spine which arises from the whole of the middorsal line. The dorsal spines on
the terminal segments decrease in height. The opposing spine is short and blunt,
terminally situated, not reaching half the width of the penultimate segment in height.
The terminal claw is stout and moderately curved, rather longer than the penultimate
segment.

The ends of the basal rays are visible as prominent, though small, tubercles in the
interradial angles of the calyx.

The radials have a strongly curved distal edge, not visible in the median line but
extending far up in the interradial angles and surrounding the ends of the basal rays;
they reach as far distally as the lateral angles of the IBr axillaries. The IBri are
laterally concealed by the interradial anterior extension of the radials and are visible
as a triangle with the apex downward in the median line; their edges are everted and
roughened. The IBr2 (axillaries) are over twice as broad as long, rhombic, rising to
a low synarthrial tubercle with the IBri, the edges all around everted and roughened,
the dorsal surface, like that of the IBn, perfectly smooth. The IIBr series are 2. The
IBr series, IIBr series, and first two brachials are in close apposition and sharply
flattened laterally.

The 20 arms are 125 mm. long. The first brachials are wedge-shaped, with the
longer side exterior. The second brachials are similar, but nearly twice as large. The
brachials following to about the tenth are oblong, about twice as broad as long, those
succeeding soon becoming triangular, broader than long, then as long as broad, and
distally wedge-shaped again and more or less elongate. The oblong brachials in the
proximal portion of the arms have both the anterior and posterior edges everted and
roughened. This soon changes to an eversion of the distal ends which are finely
spinous, and then to a strong overlapping of the distal ends. The brachials in the
proximal third of the arms have the dorsal surface perfectly smooth. In the outer
two-thirds the dorsal surface is thickly set with longitudinal lines of fine spines directed
forward, giving the outer part of the arms a peculiar velvety appearance. In the
proximal third the arms are remarkably deep and compressed; in the outer two-thirds
they are dorsally somewhat sharply rounded.

PI is 8 mm. long with 20 segments, of which the first three are not so long as broad
with the corners cut away and those following are about as long as broad, gradually
becoming elongate, and distally about twice as long as broad. This pinnule is con-
siderably longer and stouter than those following. It is stout basally, tapering grad-
ually to a slender and delicate tip. On the outer side of the postradial series it is
sharply flattened exteriorly.

A MONOGRAPH OF THE EXISTING CRINOIDS 51

The next three pinnules, P2, P3, and P4, are 6 mm. long with 15 segments most of
which are about as long as broad, the basal two or three rather shorter, the distal
rather longer. The pinnules following are of the same length but rather broader and
more sharply carinate, distally becoming rather longer though remaining comparatively
stout. The distal pinnules are 9-10 mm. long with the first segment rounded-triangular,
concave distally, the second squarish, and the remainder longer than broad becoming
about twice as long as broad distally.

The disk is scantily plated, except along the ambulacra, but the brachial and pin-
nule ambulacra are well plated. Sacculi are abundant on the brachial and pinnule
ambulacra.

The color in alcohol is yellowish brown, and the containing liquid is stained the
same color.

Notes. — The original description of Antedon aster was entirely inadequate and
misleading. I wrote:

This species is nearest to Antedon quinquecostata Carpenter (=A. com/era Hartlaub), of which
I have 7 Japanese examples [ = Slenometra diadema] for comparison; but the cirri are shorter and
proportionately stouter, with 35-40 joints, the radials [i. e., IBr series] and brachials are rounded and
not compressed, the former with their edges armed with fine teeth, the distal brachials strongly over-
lapping, the distal half as well as the distal edge of each joint beset with numerous fine teeth.

Color in life bright yellow.

The locality was given as Albatross station 5088.

In the specimen from Dr. Mortensen's station 25 the centrodorsal is conical, 4 mm.
broad at the base and 4 mm. high, with the free parts beset with fine spinelets. The
cirrus sockets are arranged in 10 columns, the two in each radial area separated by a
bare region. The cirrus sockets are not sculptured. The cirri are XXIII, 50-64,
32-42 mm. long. The IIBr series are 2. The 20 arms are 90 mm. long. The distal
intersyzygial interval is 5-8 muscular articulations. PI is 9 mm. long with 24 segments.
P2 is 7.5 mm. long with 18 segments. P3 is 6.5 mm. long with 16 segments. The
distal pinnules are 9.5 mm. long with 21 segments. The disk is incised, almost naked,
7-10 mm. in diameter. The anal funnel is 3.5 mm. long, inserted in the right side of
the anal intcrradius.

In a specimen from Mortensen's station 15, as described by Gisleii, the centrodorsal
is a low cone 1.8 mm. high. The cirri are XXVI, 39-47, 20-30 mm. long; the longest
segment is half again as long as broad. The 17 arms are 65 mm. long. The IIBr
series are 2. The radials are 10 times as broad as long. The IBri is four times as broad
as long. The IBr2 (axillary) has a moderate synarthrial backward projection and, like
the IBrb an insignificant median carination. All the ossicles are bordered with fine
spinelets, in the distal parts of the arms covering the distal half of the brachials and the
weak middorsal carination. The proximal portions of the arms are rounded. The
intersyzygial interval is 4-6 muscular articulations. PI is 3.7 mm. long with 12
segments. P2 is 2.5 mm. long with 9 segments. Ps is 1.5 mm. long with 7 segments.
The distal pinnules are 7 mm. long with 11-13 segments and are thickly beset with fine
spinelets. The disk is strongly incised ; the larger diameter is 6 mm. and the smaller
2.5 mm. There are sparse granules along the ambulacral furrows. The anal cone is
1.8 mm. high.

52 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In another specimen from Mortensen's station 15 the cirri are broken. The 15
arms are 65 mm. long. PI is 4.5 mm. long with 14 segments.

Localities. — Albatross station 5088; Sagami Bay, Japan; Joka Sima Light bearing
S. 65° E., 7.7 miles distant (lat. 35°11'25" N., long. 139°28'20" E.); 675-740 meters;
green mud; bottom temperature 5.44° C.; October 25, 1906 [A. H. Clark, 1907, 1908,
1909, 1912, 1918] (1, U.S.N.M., 22636).

Sagami Bay; off Misaki; yacht Golden Hind, Alan Owston, June 1903 [A. H. Clark,
1908, 1909, 1911, 1912, 1918; H. L. Clark, 1916] (1, U.S.N.M., 22696 [original No.
8141]).

Sagami Bay; off Okinose; 730 meters; yacht Golden Hind, Alan Owston, March
1900 [A. H. Clark, 1908] (1, U.S.N.M., 48497 [original No. 6679]).

Dr. Th. Mortensen's Pacific Expedition 1914-1 6 station 25 ; Sagami Bay ; off Okinose ;
183 meters; hard bottom; June 26, 1914 [Gislen, 1924, 1927, 1934].

Dr. Th. Mortensen's Pacific Expedition 1914-16 station 15; Sagami Bay; 730
meters; June 1-7, 1914 [GislSn, 1924, 1937, 1934].

Geographical range. — Known only from Sagami Bay, Japan.

Bathymetrical range. — From 183 to 730 (?740) meters.

Thermal range. — One record, 5.44° C.

History. — This species was originally described in 1907 under the name Antedon
aster from a specimen that had been dredged at station 5088 in Sagami Bay, Japan,
by the Albatross hi 1906. Later in the same year Antedon aster was referred to the
new genus Thalassometra. In 1908 another specimen of Thalassometra aster was
recorded from off Okinose, Sagami Bay, and at the same tune a very fine example from
off Misaki was described under the name of Thalassometra komachi. Both of these
had been dredged by Alan Owston in his yacht the Golden Hind. They formed part
of the large collection of crinoids purchased from Mr. Owston by Frank Springer and
deposited in the United States National Museum. In 1909 Thalassometra komachi
was referred to the new genus Cosmiometra.

Further study had shown that Cosmiometra komachi was merely a fully grown
example of the species originally described as Antedon aster and in 1915 this form was
listed as Cosmiometra aster, under which name it has since appeared .

In 1914 Dr. Th. Mortensen had dredged three specimens of this species in Sagami
Bay, two small ones at station 15 and a larger one at station 25. Dr. Torsten Gisle'n
figured an articulation of a distal pinnule of one of these in 1924, and recorded and
gave notes on all three in 1927.

COSMIOMETRA PHILIPPINENSIS A. H. Clark

PLATE 5, FIGURE 16; PLATE 6, FIGURE 22

Cosmiometra philippinensis A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 548 (description;

Albatross station 5523; also station 5424) ; Crinoids of the Indian Ocean, 1912, p. 215 (synonymy;

locality) ; Unstalked crinoids of the Siboga-Exped., 1918, p. 153 (in key; range), p. 155 (synonymy;

detailed description; Stations 95, 253, 254), pp. 272, 274 (listed), pi. 23, fig. 61.
Cosmiometra helene A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 427 (description; Siboga

station 253); Unstalked crinoids of the Si&oga-Exped., 1918, p. 155 (identity). — H. L. CLARK,

Biol. Res. Fish. Exper. F. I. S. Endeavour, 1909-14, vol. 4, 1916, pt. 1, p. 26 (comparison with

C. dasybrachia) .

A MONOGRAPH OF THE EXISTING CRINOIDS 53

Diagnostic features. — A moderately slender species with 20 arms; the cirri, which
are arranged in 10 definite columns on a conical centrodorsal, are in general about one-
third the length of the arms; and the elements of the division series and first two bra-
chials have the median third smooth and the lateral thirds finely spinous or tubercular.
The arms are 100-130 mm. long, and the cirri, which are rather stout, are 35-47 mm.
long with 45-61 segments.

Description. — The centrodorsal is conical, about 4 mm. broad at the base and 4 mm.
long. The cirrus sockets are arranged in 10 columns, 2 to each radial area, with 2 or 3
sockets to a column. The columns in each radial area are separated in the midradial
line by a broad bare more or less finely spinous area which is about equal in width to
a column of cirrus sockets. Outwardly the columns of cirrus sockets are in close
apposition with those of the adjacent radial areas.

The cirri are XX, 45-54 (the longer 49-54), from 35 mm, to 42 mm. in length, and
stout. The first segment is short, and those following gradually increase in length to
the fourth, which is about twice as broad as long, and the fifth, which is about half
again as broad as long. The sixth is a transition segment, from half again to twice as
long as broad. The following segments gradually decrease in length, becoming about
as long as broad at about the eleventh and twice as broad as long after the fifteenth.
After the eighth or ninth the distal dorsal edge of the segments becomes slowly prom-
inent so that the segments after the fifteenth or sixteenth are provided with a high and
prominent dorsal spine as in the other species of the genus.

The ends of the basal rays are visible as small but prominent tubercles in the angles
of the calyx.

The radials are concealed by the centrodorsal, or just visible in the midradial line.
The IBri are more or less crescentic, convex proximally, about 4 times as broad as long,
with finely serrate edges and with the lateral two-thirds of the dorsal surface finely
spinous. The IBrj (axillaries) are broadly pentagonal or rhombic, with blunted lateral
angles, twice as broad as long, with the edges finely serrate and the dorsolateral edge
bearing a few small spines. The IIBr series are 2. The division series and first brachials
are sharply flattened laterally.

The 19 arms in the type specimen are 130 mm. long. The first brachials are
slightly wedge-shaped, about twice as broad as long exteriorly. The second brachials
are similar, but nearly twice as large. The first syzygial pair (composed of brachials
3+4) is oblong, half again as broad as long. The following 6 brachials are approximately
oblong, about two and one-half times as broad as long, then becoming very obliquely
wedge-shaped, half again as broad as long, toward the middle of the arm as long as
broad, distally less obliquely wedge-shaped, and terminally longer than broad. The
arms increase slightly in width to the twelfth or fourteenth brachials, then slowly taper
distally. The proximal third of the arm is very deep and strongly compressed laterally;
the outer two-thirds is rather sharply rounded dorsally. After the oblong proximal
brachials the distal ends of the brachials begin to project as a serrate overlap which
characteristically in the outer half of the arms becomes very pronounced and is
accompanied by a fine spinosity of the dorsal, but not lateral, surface.

The pinnules are essentially as in C. aster.

The color is bright yellow.

54 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Notes. — Of the three specimens from Albatross station 5424 two have 19 and one has
20 arms from 100 to 110 mm. long; the cirri are 35-40 mm. long. These are somewhat
smaller and more delicate than the type specimen from Albatross station 5523, described
above, with slightly more projecting edges on the elements of the division series and
proximal brachials.

The specimen from Siboga station 95 is young with 13 arms 45 mm. long and the
longest cirrus 21 mm. long with 40 segments.

One of the specimens from Menado Bay, Celebes, has 19 arms. The midradial
areas on the centrodorsal are triangular with the surface smooth and hollowed, the
curved proximal border exposing the spinous surface of the radial. At the rim of the
centrodorsal these bare midradial areas are twice the width of the adjacent cirrus
sockets, the converging sides coming to a point between the apical cirri. The cirri are
XXXV, 52-55, rather stout. The ornamentation on the sides of the IBr series is
composed largely of prominent isolated low tubercles. A similar specimen has 20
arms; the cirri have 58-61 segments. In some of the specimens the bare radial areas
on the centrodorsal are narrow, their basal width less than that of a cirrus socket, and
short, while in others they are broad. Some have the lateral ornamentation on the
division series entirely spinous, while in others it is more or less tubercular.

The specimen from Siboga station 253 was described as a new species, Cosmiometra
hekne, in the following terms. The centrodorsal is moderate in size, truncated conical,
about 4.5 mm. broad at the base and about 2.5 mm. high interradially. The cirrus
sockets are arranged in 10 columns of 2 or 3 each; interradially the columns are in
close apposition, but in the midradial line they are separated by a wedge-shaped area,
at first about as broad as a cirrus socket, but with converging sides that come together
just beyond the last cirrus sockets; this bare midradial area is entirely covered with
fine, more or less sharp, granulations. The dorsal pole is irregular, 2 mm. in diameter.

The cirri are moderately stout, 37—47 mm. long with 52-61 segments of which the
first four are very short, the fifth is over twice as broad as long, the sixth, a transition
segment, is half again as long as broad, and the seventh is slightly longer than the sixth.
The segments following gradually decrease in length, becoming about as long as broad
on the thirteenth, twice as broad as long on the twentieth, and shorter distally. Dorsal
processes begin on the thirteenth and gradually increase in height. The dorsal spines
are high and strongly carinate, V-shaped in end view, the two distal edges finely serrate.
At the tip of the cirri they become narrower and smooth.

The radials are entirely concealed. The IBri are short, about four times as broad
as the lateral length, slightly convex proximally, distally incised by a rounded process
from the axillary so that the median length is only about two-thirds of the lateral.
The proximal border is armed with very numerous fine short spines. The distal border
is similarly modified, but the spines become more-or-less obsolete in the median third.
The lateral borders are similarly modified, but the spines extend farther inward over
the dorsal surface of the ossicle and are more developed. The lateral thirds of the dorsal
surface of the IBri are rather thickly covered with fine short spines. The IBr2 (axil-
aries) are rhombic, somewhat over twice as broad as long, with the lateral angles
truncated. The lateral sides, formed by the truncation of the lateral angles, are only
about one-third as long as the sides of the IBr,. The proximal borders are modified
like the corresponding borders of the IBr,. The distal borders are very finely spinous.

A MONOGRAPH OF THE EXISTING CRINOIDS 55

The lateral fourths of the dorsal surface arc covered rather thickly with fine short spines
like the lateral thirds of the IBr,. The synarthrial tubercles are low and only slightly
marked. The division series are only slightly convex dorsally, sharply flattened
laterally, and in very close apposition. The IIBr series are 2, the component ossicles
resembling those of the IBr series, but with the proximal and distal borders more finely
spinous and the spinous modification of the lateral portion of the dorsal surface rela-
tively narrower exteriorly and very narrow interiorly.

The 20 arms are from 95 to 100 mm. long. The spinous modification of the lateral
portion of the dorsal surface of the ossicles of the division series runs up in a very narrow
and progressively narrowing band both internally and externally as far as the third or
fourth brachial. The proximal oblong brachials have very slightly everted edges. As
the brachials become triangular serrate longitudinal striations appear, first only in the
median line, but soon over the entire dorsal surface of the brachials, which have slightly
overlapping and spinous distal edges.

The specimen from Siboga station 254 is similar to that from station 253 just
described. There are 20 arms about 95 mm. long. The cirri have 56-60 segments
and are 35HIO mm. long.

Of the three specimens from the Danish Expedition to the Kei Islands station 12
one has 19 arms about 100 mm. long and the longest cirri 45 mm. long with 59 segments.
The two others have 20 arms about 100 mm. long.

The specimen from the Danish Expedition to the Kei Islands Station 56 has 20
arms 105 mm. long. The longest cirri have 53-59 segments.

Localities. — Albatross station 5424; Jol6 (Sulu) Sea; Cagayan Island (S.) bearing
S. 11° W., 3.4 miles distant (lat. 9°37'05" N., long. 121°12'37" E.); 621 meters; bottom
temperature 10.2° C.; coral sand; March 31, 1909 [A. H. Clark, 1911, 1912; H. L. Clark,
1916] (3, U.S.N.M., 35597).

Albatross station 5523; in the vicinity of northern Mindanao; Point Tagolo Light
bearing S. 48° W., 6.7 miles distant (lat. 8°48'44" N., long. 123°27'35" E.); no further
data; August 10, 1909 (A. H. Clark, 1911, 1912; H. L. Clark, 1916] (1, U.S.N.M., 27497).

Siboga station 95; northwest of the Tawi Tawi Islands, Sulu (Jol6) Archipelago
(lat. 5°43'30" N., long. 119°40'00" E.) ; 522 meters; stony bottom; June 26, 1899 [A. H.
Clark, 1918] (1, Amsterdam Mus.).

Menado Bay, northern Celebes (lat. 1°31' N., long. 124°47' E.); 457 meters; Capt.
H. Christiansen, Great Northern Telegraph Company, March 12, 1913 (8, U.S.N.M., E.
3214; C. M.).

Siboga station 253 ; Kei Islands (lat. 5°48'12" S., long. 132°13'00" E.) ; 304 meters;
gray clay, hard and crumbly; December 10, 1899 [A. H. Clark, 1912, 1918] (1, Amster-
dam Mus.).

Siboga station 254; Kei Islands (lat. 5°40' S., long. 132°26' E.); 310 meters; fine
gray mud; December 10, 1899 [A. H. Clark, 1918] (I, U.S.N.M., E. 454).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 12; 320 meters;
sand; April 9, 1922 (3, U.S.N.M., E. 3145; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 245 meters;
May 10, 1922 (1, C. M.).

Geographical range. — From the Philippine Islands south to Celebes and the Kei
Islands.

56 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Bathymetrical range — From 245 to 621 meters; the average of seven records is 397
meters.

Thermal range. — One record, 10.2° C.

History. — This species was originally described under the name of Cosmiometra
philippinensis from a single specimen from Albatross station 5523. I wrote that it is
most closely related to C. komachi (=aster) from southern Japan, but the division series
and oblong lower brachials are smooth, without the broadly everted and roughened edges
and the rounded median linear tubercles of the latter, and the bare midradial areas on
the centrodorsal are much broader. I said that both these species are related to C.
woodmasoni which, however, appears to differ in the greater compression of the division
series and consequent apparent narrowness of the lower part of the animal, and in the
shortness of its cirri, which are said to have 35-45 segments, though figured with 35
(fig. 1) and 50 (figs. 2, 3). Three additional specimens from Albatross station 5424 were
recorded, and notes on these were given.

In 1912 I described as a new species Cosmiometra helene from Siboga station 253.
In my memoir on the unstalked crinoids of the Siboga expedition published in 1918 I
placed C. helene in the synonymy of C. philippinensis which I recorded from stations 95,
253, and 254, giving notes on the specimens.

COSMIOMETRA CONIFERA (Harllanb)

PLATE 3, FIGURES 10, 11; PLATE 4, FIGTJRE 15
[See also vol. 1, pt. 1, fig. 366, p. 297; pt. 2, fig. 213, p. 155; figs. 843-848, p. 405.)

Anledon com/era HARTLAUB, Nachr. Ges. Gottingen, May 1890, pp. 169, 173 (description; Japan);
Nova Acta Acad. German., vol. 58, No. 1, 1891, p. 76 (detailed description and comparisons;
Japan, deep water), pi. 4, fig. 46; pi. 5, figs. 51, 56. — HAMANN, Bronn's Klassen und Ordnungen des
Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed).— A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33,
1907, p. 145 (considered as a synonym of A. quinquecostata) ; vol. 34, 1908, p. 466 (listed); vol. 43,
1912, p. 384 (= Cosmiometra conifera); Crinoids of the Indian Ocean, 1912, p. 37 (identity). — •
HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 309 (systematic position; history).

Stenometra conifera A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed).

Cosmiometra conifera A. H. CLARK, Vid. Medd. Naturhist. Foren. K0benhavn, 1909, p. 186 (allied to
C. crassicirra); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 384 (identity), p. 404 (Japan); Crinoids
of the Indian Ocean, 1912, p. 37 (identity), p. 214 (synonymy; locality); Journ. Washington
Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance);
Unstalked crinoids of the Siboga-Exped., 1918, p. 154 (in key; range; references). — GISLEN,
Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.

Diagnostic features. — A species with 20 arms in which the elements of the division
series and first two brachials are entirely smooth dorsally; and the cirri, which are
arranged in 10 definite columns on a conical centrodorsal, are long and slender, slightly
more than half as long as the arms, with about 70 segments. The arms are about 70 mm.
long, and the cirri are 45 mm. long.

Description. — The centrodorsal is conical with a moderately broad stellate base the
five angles of which are interradial and are produced ventrally. There are about 40
cirrus sockets which are arranged in 10 columns of 4 each. The columns are separated
by rather low radial and interradial ridges of which the interradial run to the angles of
the pentagonal base. The 10 ridges are of equal height and size, but the radial are
slightly broadened at the lower end.

A MOXOGRAPH OF THE EXISTING CR1-VOIDS 57

The cirri arc about XL, about 70, about 45 mm. long. They arc moderately stout
and only slightly tapering. They are somewhat compressed laterally and when diy
have the appearance of ivory. The first 5 or 6 segments are short, the next longer than
broad, and the 3 or 4 following about as long as broad. The remainder arc shorter,
especially toward the end of the cirri. When viewed from the side the cirri have a
deeply serrate dorsal profile from about the fifteenth segment on, resulting from t lie-
presence of dorsal tubercles. There are no true spines except on the penultimate
segment.

The radials are plainly visible in the interradial angles. The IBri are short and are
entirely united laterally. The IBr2 (axillaries) are rhombic. The IIBr series are 2.
The division series and first brachials have sharply flattened sides.

The 20 stout arms, which have an uneven dorsal surface, are probably about 70 mm.
long. The first brachials are short, rhombic, and laterally united interiorly. The
second brachials are a good deal longer than the first and are longer exteriorly than
interiorly. The first syzygial pair (composed of brachials 3 + 4) is approximately as
long as broad. The following 6 or 7 brachials are bluntly wedge-shaped, and then
comes a series of triangular brachials of which the distal edge overlaps the base of
the brachial following with alternating lateral processes. Farther out the brachials
become wedge-shaped again, finally becoming more and more oblong. All the brachials
with the exception of the first two have produced and overlapping finely serrate distal
edges. The distal portion of the arm has a sharp dorsal longitudinal carination.

Syzygies occur between brachials 3 + 4, again from between brachials 19 + 20 to
between brachials 26 + 27 (usually between brachials 26+27), and distally at intervals
of 4-8 muscular articulations. The syzygial unions are not smooth exteriorly, but
are almost the same as the muscular articulations.

PI and Pa are slender and taper rapidly from the somewhat broadened basal
segments; they are about 11 mm. long with 15-20 segments the majority of which are
elongated and cylindrical. The pinnules of the three following pairs decrease gradually
in length. The smallest pinnule is Pd, which is only 4 mm. long. The segments of
these pinnules are flatter and broader than those of the pinnules of the first pair
(P] and P»). The following pinnules reach a length of 11 mm. and are remarkable
for their broad flat segments.

The ambulacral groove of the pinnules is provided with well-developed side and
covering plates. Sacculi are few and small.

The disk is 14 mm. in diameter.

The skeleton is brownish white, the disk dark brown.

Notes. — As Dr. Hartlaub said, the type specimen is badly broken. All the arms
and cirri are broken off, and in general the pinnules are not preserved. Only the
proximal portion of the animal and the arm bases are well preserved. I have examined
the type specimen, which was well described by Hartlaub.

Locality. — Japan; Dr. Franz Martin Hilgendorf: "Dr. Hilgendorf told Dr. Hartlaub
personally that according to his recollection the specimen came from deep water
[Hartlaub, 1890, 1891; A. H. Clark, 1907, 1909, 1912, 1915, 1918; Gislen, 1934] (1,
Berl. Mus., 2830).

History. — This species was described under the name of Antedon conrfera by Dr.
Clemens Hartlaub in 1890, and was redescribed and figured in the following year.

843803—50 5

58 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Hartlaub said that of the other species of the Spinifera group it comes nearest Antedon
(Stenometra) quinquecostata Carpenter. Like that species it is characterized by a
large number of cirrus segments and a definite arrangement of the cirri. He said that
in quinquecostata the centrodorsal is more columnar and the cirri are not arranged in
10 columns but in 5 double columns, the 5 double columns being separated by 5 espe-
cially high ridges instead of the 10 ridges seen in conifera. But the most important
difference is that the arms of quinquecostata have a sharp middorsal keel which in
conifera is observable only on the outermost ends of the arms.

In 1907 I placed Antedon conifera in the synonj^my of A. quinquecostata, of which
I said I had seven Japanese specimens. These Japanese specimens represent in reality
Stenometra diadema (see page 18). Just why I should have considered conifera a
synonym of the very different quinquecostata I cannot now recall. In 1909 I transferred
conifera to the genus Stenometra, and later in the same year to Cosmiometra. In 1912
I mentioned that I had examined the type specimen of Antedon conifera, but gave no
additional information regarding it. Everything we know concerning this species is
included in the original description.

COSMIOMETRA CRASSICIRRA (A. H. Clark)

PLATE 10, FIGURE 33

Thalassomdra crassicirra A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214 (in key), p. 225
(description; Albatross station 3882; the specimen from station 4107 is the type specimen of
Stiremetra decora).

Cosmiometra crassicirra A. H. CLARK, Proc. Biol. Soe. Washington, vol. 22, 1909, p. 17 (listed); Vid.
Medd. Naturhist. Foren. K0benhavn, 1909, p. 186 (allied to C. conifera}; Crinoids of the Indian
Ocean, 1912, p. 215 (synonymy; locality); Unstalked crinoids of the Siboga-Kxped., 1918, p. 154
(in key; range; references). — GISLIJN, Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No.
11, 1934, p. 20. — A. H. CLARK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (Albatross station
3882), p. 93 (station data).

Diagnostic features. — A species with 20 arms in which the elements of the division
series and first two brachials are entirely smooth dorsally, and the cirri, which are
irregularly arranged in 1, 2, or 3 columns in the several radial areas of the short col-
umnar or almost discoidal centrodorsal, are moderately slender, about one-third of the
arm length, with 50-54 segments. The arms are 130 mm. long, and the cirri are 45 mm.
in length.

Description. — The centrodorsal is broad, short columnar or almost discoidal, with
the cirrus sockets arranged in 1, 2, or 3 columns in each radial area. One of the radial
areas has 2 marginal columns of cirrus sockets separated by a median space nearly as
wide as the cirrus sockets themselves, 3 of the radial areas have 3 columns of cirrus
sockets, and the remaining radial area has a single median column of cirrus sockets.
There are 1 or 2 cirrus sockets in each column. The broad and flat dorsal pole and the
sides of the centrodorsal where there are no cirrus sockets are very rough.

The cirri are XVII, 50-54, 45 mm. long, moderately slender. The first 4 segments
are short, the fifth is about as long as broad, and those following to the fourteenth or
sixteenth are about half again as long as broad. The sixteenth is a transition segment;
it is but little longer than broad; the distal half or third has a polished surface, the
proximal half or two-thirds a dull surface. The next few segments after the transition
segment are slightly broader than long, and those succeeding gradually become shorter.

A MONOGRAPH OF THE EXISTING CRIXOIDS 59

All the segments from the transition segment omviml bear prominent dorsal spines
which on the 3 or 4 terminal become very small. The opposing spine is low, less than
one-fourth the width of the penultimate segment in height, and rounded. The ter-
minal claw is longer than the penultimate segment, stout, and moderately curved.

The disk is naked, except for a few scattered granules near the periphery. The
brachial ambulacra are naked. The pinnule ambulacra have moderately developed
side and covering plates. The sacculi are small.

The ends of the basal rays are visible as irregular tubercles in the intcrradial angles
of the calyx.

The radials are concealed by the centrodorsal. The IBr, are almost entirely con-
cealed, but their apposed sides are visible as triangles in the interradial angles. The
IBr2 arc rhombic, about twice as broad as long, produced posteriorly over the IBr,,
with the borders slightly prominent and a moderately sharp median keel. The HIV
series arc 2, with the axillary rhombic and over twice as long as the preceding ossicle;
both are bluntly carinate in the median line, and their borders are slightly prominent.
The division series are sharply flattened laterally and are in close lateral apposition.
The first 15 brachials are also sharply flattened laterally.

The 20 rather slender arms are 130 mm. in length. The first 2 brachials are wedge-
shaped, the latter larger than the former and with a rounded posterior projection. The
following 11 brachials are oblong or slightly wedge-shaped, about twice as broad as
long, those succeeding gradually becoming somewhat more obliquely wedge-shaped,
about as long as broad, and slowly less obliquely wedge-shaped distally, and elongate
terminally. After about the proximal third of the arm the brachials develop promi-
nently overlapping distal edges which are armed with fine spines. The arms are strongly
compressed laterally in the basal third, and moderately compressed distally.

Syzygics occur between brachials 3+4, again between brachials 23 + 24 and 32 + 33
and distally at intervals of from 4 to 9 muscular articulations, the intersyzygiaJ interval
decreasing distally.

PI is 7 mm. long, considerably stouter than P2 though not especially enlarged,
tapering evenly from the base to the tip. It is composed of 15 segments all of which
are about as long as broad, P2 is 5 mm. long with 13 segments of which the first is about
as long as broad and those following become progressively elongated, reaching a length
of 2 or 3 times the width distally. The following pinnules gradually decrease in length
to P8 or P7, then become rather more slender and increase to 7 mm. distally.

The color in alcohol is brownish yellow, the calyx and arm bases to the fourth
brachial dark brown, the cirri light yello \visli.

Locality. — Albatross station 3S82; Hawaiian Islands; Pailolo Channel, between
Maui and Molokai; Mokuhooniki Islet bearing N. 30° W., 3.1 miles distant; 249 meters;
sand, coral, and rock; bottom temperature 17.5° C.; April 16, 1902 [A. H. Clark, 1908,
1909, 1912, 1918, 1949; Gislen, 1934] 1, U.S.N.M., 22689).

History. — This species was described under the name of Thalassometra crassicirra
in 1908 from a single specimen from Albatross station 3SS2;at the same time another
small 10-armed specimen from station 4107 was recorded which is regarded herein as the.
type specimen of Stiremetm decora (see page 134). In 1909 crassicirra was removed
to the new genus Cosmiometra. It has not been rediscovered since it was originally
described.

60 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

COSMIOMETRA WOODMASONI (Bell)

Antedon wood-masoni BELL, Journ. Linn. Soc. (Zool.), vol. 24, No. 154, May 5, 1893, p. 340 (descrip-
tion; Sahul Bank), pi. 23; pi. 24, fig. 1. — [BELL], Crustacea, Echini, Peripatus, Worms, and An-
thozoa, 1906, p. 747.

Thalassometra wood-masoni A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Cosmiometra woodmasoni A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 17 (listed); Proc.
U. S. Nat. Mus., vol. 39, 191], p. 549 (compared with C. philippinensis);vol. 40, 1911, p. 38 (com-
pared with C. gardineri); Mem. Australian Mus., vol. 4, 1911, p. 795 (synonymy; Sahul Bank);
Crinoids of the Indian Ocean, 1912, p. 214 (synonymy; locality); Smithsonian Misc. Coll., vol.
61, No. 15, 1913, p. 44 (published reference to specimen in the B. M.; locality; comparison with C.
crassicirra); Unstalked crinoids of the Siboga-Exped., 1918, p. 154 (in key; range), p. 155 (ref-
erences).

Diagnostic features . — A species with 20 arms in which the elements of the division
series and first two brachials are entirely smooth dorsally with a narrow and moderately
high median carination and the lateral edges not produced; and the short and rather
stout cirri have 40^11 segments. The arms are 110 mm. long, and the cirri are 27 mm.
in length.

Description. — Professor Bell's description of this species is as follows :

This new species belongs to Carpenter's Spinif era-group ; that is, it is bi-distichate [with the II Br
series 2] and has some of the basal joints more or less wall-sided. As it has more than thirty cirrus-
joints, the more distal of which are spiny, the first pinnule as long as or longer than the second, and
the cirri not arranged in rows on the centro-dorsal, it stands nearest to A. [Horaeometra] duplex (P.
H. C. MSS) and A. [Stiremetra] lusitanica. The former of these has from 30-40 cirrus joints, the
latter 50; the present would appear to have from 35 to 45; the radial axillaries [IBr2] are short and wide
as in A. lusitanica, and there is no noticeable expansion of any of the joints of the pinnules.

The following may serve as a specific diagnosis:

A member of the Spinifera group, and falling under the same subdivision as A. duplex and A.
lusitanica. Centrodorsal rather large, but not columnar, the central portion free of cirrus-sockets;
about 18 [XVIII] cirri, with 35-45 joints; these begin to be spiny at about the tenth joint, and the
spine, though not large, is quite well marked. First radials [radials] hidden, the second [IBrj] much
wider than long, slightly concave on its distal side; the axillaries [IBr2] wide, with two slight concavities
for the reception of the first distichal [IIBri], which again is much wider than long; the distichal axillary
[IIBr2] of much the same shape as the radial [IBr2]; the two visible radials [ossicles of the IBr series]
and the distichals [IIBr series] have a median linear tubercle.

20 arms. Basal joints with fairly regular sides; the third a syzygy [a syzygy between brachials
3 + 4]; then one, ordinarily, on the 12th [between brachials 13+14] or 14th [between brachials 15+16]
joints. The arm-joints gradually become triangular, flattened from side to side, and provided with a
median ridge. The pinnules are styliform, but short and with simple joints; they increase somewhat
in length nearer the end of the arm.

Diameter of disk 6 millim. Length of arms 1 10 millim.

Colour white, with faint patches of brown here and there.

I examined the type specimen at the British Museum in London in 1910. The
arms are 110 mm. long, and the cirri are comparatively short and stout, 27 mm. long
with 40-41 segments of which the seventh is a transition segment. In my notes I
wrote that in general this species resembles C. crassicirra from the Hawaiian Islands;
the division series are strongly, but roundedly, carinate. In my diagnosis of Cosmio-
metra gardineri I said that it is closely related to C. woodmasoni, but the cirri are shorter
and stouter, with proportionately shorter segments ; the carination of the division series
is narrower, and the lower brachials have only a faintly indicated crest; the distal
brachials are overlapping and narrowly carinate. In my description of Cosmiometra
philippinensis in 1911 I noted that this species differs from it in the greater compression

A MONOGRAPH OF THE EXISTING CRINOIDS 61

of the division series and consequent apparent narrowness of the lower part of the
animal, and in the shortness of the cirri.

Locality. — Sahul Bank, south of the southern end of Timor (lat. 11°30' S., long.
125° E.); from a cable [Bell, 1893 ("Sahul Bank, North Australia"), 1906; A. H. Clark,
1907, 1909, 1911, 1912, 1913, 1918] (1, B. M.).

History. — This species was originally described under the name of Antedon wood-
masoni by Prof. F. Jeffrey Bell in 1893 from two or more specimens that had been found
attached to a cable crossing the Sahul Bank (see under Asterometra mirifica, Part 4b,
p. 434). Professor Bell did not give the number of specimens, but said that the
species was represented in the British Museum and in the Indian Museum at Cal-
cutta. In a guide to a portion of the invertebrate exhibits published in 1906 Professor
Bell mentioned this species, so the British Museum must possess at least two.

In 1907 I placed wood-masoni in the new genus Thalassometra , and in 1909 trans-
ferred it to the new genus Cosmiometra. In 1910 I examined the single specimen (the
type) in the study collection of the British Museum, but overlooked the specimen or
specimens in the exhibition hall. In 1911 I compared this species with the new species
Cosmiometra philippinensis, and in another paper published in the same year with the
new species C. gardineri. In my memoir on the Recent crinoids of Australia published
in 1911 Cosmiometra woodmasoni was included and the synonymy was given. In my
memoir on the crinoids of the Indian Ocean published in 1912 I published notes on the
type specimen in the British Museum, and compared it with the Hawaiian C. crassicirra.
I did not find any specimen of this species in the Indian Museum collection. My notes
on the type specimen were republished in a paper on the crinoids of the British Museum
in 1913. In my memoir on the unstalked crinoids of the Siboga expedition published
in 1918 woodmasoni was included in a key to the species of Cosmiometra, together with
its range, and the synonymy was given.

COSMIOMETRA IOLE. ef. DOT.

PLATE 4, FIGURE 14

Diagnostic features. — A species with 20 arms in which the elements of the division
series and first two brachials are entirely smooth dorsally with a narrow and moderately
high median carination and the lateral edges produced and slightly everted, broadly
scalloped or bearing two or three blunt tubercles; the cirri, which are irregularly ar-
ranged on a large columnar centrodorsal are short and moderately stout with 29-35
segments. The arms are 100 mm. long, and the cirri are 25 mm. in length.

Description. — The centrodorsal is large, columnar with converging sides, the broad
dorsal pole 3 mm. in diameter and thickly beset with papillae which tend to be arranged
in radiating interradial lines. The cirrus sockets are very closely crowded and are
irregularly arranged. Interradially the rim of the centrodorsal is raised into a high
crest which reaches the everted lateral borders of the radials.

The cirri are XVII, 29-35, 25 mm. in length, and moderately stout. The first seg-
ment is very short, and those following slowly increase in length to the fifth, which is
somewhat more than twice as broad as long. The sixth is about twice as long as broad
and is a transition segment with the proximal three-quarters dull and the distal qunrtrr
whitish and highly polished. This segment is constricted, the maximum depth of the
constriction being just before the polished distal portion. The seventh segment is

62 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

about half again as long as broad, and the eighth is usually about one-third again as
long as broad. The following segments decrease in length, those in the terminal fourth
or fifth of the cirri being nearly twice as broad as long. The eighth segment has the
dorsal portion of the distal edge very slightly produced and finely spinous. On the
segments succeeding this production of the distal edge becomes narrower and higher
and involves more of the dorsal surface, in the segments of the terminal portion of the
cirri narrowing into a high dorsal spine with a rounded dorsal crest. The first cirrus
segment commonly bears a small tubercle resembling those on the dorsal surface of the
centrodorsal.

The ends of the basal rays are visible in the angles of the calyx as distinct tubercles,
or as a continuation of the interradial crests on the centrodorsal.

The distal portion of the radials is visible as a narrow curved band just beyond
the rim of the centrodorsal. The anterolateral angles are separated by a slight notch,
and may be produced into a small high tubercle. The IBr, are narrow, four times as
broad as long, with the proximal and distal borders parallel. The lateral edges are
produced and slightly everted, and are broadly scalloped or bear two or three blunt
tubercles. The proximal border may be either unmodified or slightly scalloped, and
may bear a tubercle at or near the posterolateral angles. A conspicuous narrow median
keel with the crest evenly convex in lateral view occupies the midliue. The IBr2
(axillaries) are low, three times as broad as long, with the lateral edges not very much
shorter than those of the IBiv The distal edges are slightly and narrowly thickened,
and the posterolateral angles are more or less produced and irregularly scalloped. A
conspicuous narrow keel, of which the crest as seen in profile is straight, occupies the
entire median line of the ossicle. The IIBr series are 2 and resemble the IBr series,
but are proportionately slightly longer with the borders of the component ossicles less
irregular. The proximal and distal borders are very slightly everted.

The 20 arms are 100 mm. long. They are narrow at the base and increase slowly
in width up to the tenth or twelfth brachial, thence very gradually tapering distally.
The first brachials are half again as long exteriorly as interiorly, and about twice as
broad as the exterior length. The inner edges are slightly produced, forming flangelike
margins which meet above the apex of the axillaries. There is a conspicuous narrow
median keel. The proximal border is slightly and narrowly everted. The second
brachials are slightly larger with the outer side slightly longer and the inner side shorter.
They bear a conspicuous median keel, and the proximal and distal borders are slightly
and narrowly everted. The first syzygial pair (composed of brachials 3+4) is from
one-third to one-half again as broad as long. Both the hypozygal and the epizygal have
a narrow median keel wliich is not so high as that on the brachials preceding. The next
four brachials are slightly wedge-shaped, and are about three times as broad as the
median length; each has a slight, but distinct, narrow median keel. The following
brachials become very obliquely wedge-shaped, or almost triangular, not quite twice as
broad as the greater length, and distally gradually less obliquely wedge-shaped and
longer. Each brachial bears a low narrow median keel with a rounded crest. The
distal edges of the brachials are slightly produced and finely spinous, the spines being
most conspicuous at the end of the median keel In lateral view the dorsal profile of
the arms is markedly serrate.

A MONOGRAPH OF THE EXISTING CRINOIDS 63

PI is 7 mm. long with 14 segments of which the first is very short, the third is
slightly broader than long, the fourth is slightly longer than broad, and the last three
or four are about twice as long as broad. The distal angles of the segments project
considerably beyond the somewhat narrowed bases of the segments succeeding, giving
the profile of the pinnule a strongly serrate ch:ir:irtiT. Though stouter, as well as
longer, than the following pinnules, P, is not appreciably enlarged.

P2 is 5 mm. long with 10 segments, resembling P, but proportionately more slender.
P3 is 4 mm. long with 9 segments, and resembles P2. P4 is 3 mm. long with 8 segments.
P5 is similar to P4. The pinnules succeeding slowly increase in length, reaching a
length of 7.5 mm. distally.

Notes. — A young specimen taken with the one described has 14 arms 85 mm. long.

Locality. — Dr. Th. Mortensen's Pacific expedition, 1914-191G; 25 miles east by
south from Zamboanga, Mindanao, Philippine Islands; 292-365 meters; hard bottom;
March 3, 1914 (2, C. M.).

COSMIOMETRA GARDINERI A. H. Clark

Cosmiomelra gardineri A. H. CLARK, Proc. U. S. Nat. Mus., vol. 10, 1911, p. 6 (Anledon carinata record-
ed by Bell from South Africa possibly this species), p. 8 (southeastern Africa), p. 38 (description;
Saya de Malha, 135 fathoms); Criuoids of the Indian Ocean, 1912, p. 41 (possible identity with
Antcdon carinala Bell, 1909), p. 214 (synonymy; Saya de Malha, 135 fathoms); Smithsonian
Misc. Coll., vol. 61, No. 15, 1913, p. 43 (published references to the specimen in the B. M.; locality;
characters; comparison with C. woodmasoni); Unstalked crinoids of the Siboga-Exped., 1918, p.
154 (in key; range; references); John Murray Exped., 1933-34, Sci. Reports, vol. 4, No. 4, 1936
(Jan. 1937), p. 101 (range), p. 104.

Diagnostic features. — A species with 20 arms in which the elements of the division
series and first two brachials are entirely smooth dorsally with a low and broad median
carination; the outer brachials are very strongly overlapping and broadly carinate;
and the cirri are slender, 30 mm. long with 29-31 segment-;.

Description. — This species is closely related to C. woodmasoni. The cirri are longer
and more slender, 30 mm. long with 29-31 segments, which are proportionately longer.
There are 20 arms. The carination of the division series is broader than it is in C.
woodmasoni. The lower brachials have a broad median keel quite different from the
faintly indicated crest of C. woodmasoni, and the outer brachials arc very strongly
overlapping and broadly carinate, the raised portion, when viewed dorsally, having a
triangular shape, the apex of the triangle being proximal; the same type of carination
is found in C. imodmasoni, but the triangles are narrower.

Locality. — Saya de Malha, Indian Ocean; 247 meters; Percy Sladen Trust Expedi-
tion to the Indian Ocean in 1905, J. Stanley Gardiner, leader; Sea Lark [A. II. Clark,
1911, 1912, 1913, 1918, 1937] (1, B. M.).

History. — The type and only known specimen of this species was secured by the
Percy Sladen Trust Expedition to the Indian Ocean on the Sea Lark under the leader-
ship of Prof. J. Stanley Gardiner in 1905, but was not mentioned by Prof. F. Jeffrey
Bell in his account of the echinodcrms of that expedition published in 1909. It \vas
described in 1911 in a paper on the crinoids of the coasts of Africa, and at the same time
it was suggested that the Antedon (Truj/ioinitra) c/iri/m/ii recorded by Bell from deep
water off Saya de Malha might be this species. It was mentioned in my memoir on
the crinoids of the Indian Ocean published in 1912, and was redescribed in my account

64 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

of the crinoids of the British Museum published in 1913. It was inserted in the key
to the species of Cosmiometra in my memoir on the unstalked crinoids of the Siboga
expedition published in 1918 and the range and synonymy were given, and it was men-
tioned in my report on the crinoids of the John Murray Expedition to the Indian
Ocean, 1933-34, published in 1937.

Genus PARAMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 222, and following
authors.

Charitometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.

Thalassometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 125.

Paramclra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (diagnosis; genotype Ante-
don orion A. H. Clark, 1907); Amer. Journ. Sci., ser. 4, vol. 32, 1911, p. 129 (characteristic of
the Japanese fauna; significance) ; Crinoids of the Indian Ocean, 1912, p. 9 (absent from Australia),
p. 10 (occurs in the Hawaiian Islands), p. 11 (absent from the west coast of the Malay Peninsula,
the Andamans, and farther west), p. 17 (significance of conditions in this genus in southern
Japan), p. 24 (range), p. 59 (in key), p. 213 (original reference; genotype); Die Crinoiden der
Antarktis, 1915, p. 125 (certain species of this genus show the characteristic features of Antho-
metra adriani). — F. W. CLARKE and WHEELER, TJ. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 195
(inorganic constituents of the skeleton) ; U. S. Geol. Surv. Prof. Pap. 102, 1917, pp. 23 and following
(same). — A. H. CLARK, Unstalked crinoids of the Stboja-Exped., 1918, pp. 146, 147, 148 (in key;
range), p. 158 (key to the included species). — F. W. CLARKE and W. C. WHEELER, U. S. Geol. Surv.
Prof. Pap. 124, 1922, p. 20 (inorganic constituents of the skeleton). — GISLEN, Ark. Zool., vol. 19, No.
32, Feb. 20, 1928, p. 8 (must be referred to the Charitometridae). — A. H. CLARK, Journ. Linn.
Soc. (Zool.), vol. 36, No. 249, April 1929, p. 649.— GISLEN, Kungl. Fysiograf. Siillsk. Handl.,
new ser., vol. 45, No. 11, 1934, pp. 18, 20.

Diagnosis. — A genus of Thalassometridae in which the brachials beyond the basal
are more or less compressed laterally and carinate or subcarinate, or at least strongly
rounded dorsally; the division series, which are all 2, and arm bases are strongly rounded
dorsally, slightly or not at all flattened against their neighbors, the individual ossicles
plain, with everted edges, or with a more or less granular surface, usually with a delicate
middorsal carinate line; and the brachial carination is not produced into overlapping
spines. The 10-20 arms are 90-170 mm. long, and the short and rather stout cirri
are 20-28 mm. long with 18-27 segments.

Geographical range. — From southern Japan and the Hawaiian Islands to the Philip-
pines, the Moluccas, the Kei Islands, and Timor.

Bathymetrical range.- — From 128 to 795 meters.

Thermal range.— From 10.78° to 15.89° C.

Remarks. — The genus Parametra is related to Cosmiometra, but it represents a
more generalized type with the division series and brachials less specialized and the
cirri short and stout with relatively few segments. The species of Parametra, with their
short and stout cirri and the scarcely modified PI, bear a considerable superficial re-
semblance to certain species in the family Charitometridae, and they have been
erroneously referred to that family both by Gisl6n and by myself.

The six species of Parametra fall into two groups. In the first and more typical
group, including compressa, granulata, orion, and lisa, the arms are carinate or sub-
carinate and PI resembles P2 except for being longer and proportionately stouter.
The species of the other group, ajax and J?sAm, have the arms rounded dorsally and
PI more or less enlarged in the basal portion, thus forming to a certain extent a transition

A MONOGRAPH OF THE EXISTING CRINOIDS 65

between the genera of Thalnssometridae with carinate arms, all the division series 2,
and a scarcely modified PI, and the genera with dorsally rounded arms, the IIBr series,
if present, usually 4(3+4), and a much enlarged PI.

History. — The first known species of this genus was described under the name of
Antedon compressa by Dr. P. II. Carpenter in 1888. A second species was described
as Antedon orion in 1907. In my first revision of the old genus Antedon published
later in 1907 compressa and orion, were both referred to the new genus Charitometra,
but in a paper published on April 11, 1908, I said that "the species compressa and
orion, placed in Charitometra, should have been referred to Thalassometra." Later in
the same year (May 14) I described Thalassometra Jisheri. In my revision of the family
Thalassometridae published in January 1909 I established the genus Parametra with
the genotype Antedon orion A. H. Clark, 1907, including in the new genus compressa,
fishcri, and orion. Parametra granulata was briefly diagnosed in 1913.

In discussing the specimens of Parametra granulata and P. compressa hi the British
Museum in 1928 Prof. Torsten Gislen said that the genus Parametra must be referred
to the Charitometridac, under which family he placed it. In 1934, however, he revised
this opinion.

KEY TO THE SPECIES IN THE GENUS PARAMETRA

a1. Arms carinate or subcarinate, at least with a low but distinct carinate line, never evenly rounded

dorsally; cirri with the transition segment the eighth; PI evenly tapering.
b1. Distal cirrus segments broader than long with prominent carinate processes; cirri about one-fifth

the arm length.
c1. Not more than 20 cirrus segments; usually 15-20 arms.

d1. Lateral portions of the division series and arm bases smooth; 15-20 arms 120-140 mm.
long; cirri 23 mm. long with 16-20 segments (from the Timor Sea to the Kei Islands and

north to Halmahera; 216-795 meters) compressa (p. 65)

d*. Lateral portions of the division series and arm bases more or less covered with fine tubercles;
12-20 (usually 17-20) arms 145-170 mm. long; cirri with 18 segments (Philippine Islands;

150-510 meters) granulata (p. 69)

c2. Cirrus segments 20-25 in fully developed individuals; usually 10-15 anna 125-140 mm. long
(Hong Kong to southern Japan from the Korean Straits to Sagami Bay; 128-306 meters).

orion (p. 72)

b1. Distal cirrus segments as long as broad with very small and obscure dorsal processes; cirri
about one quarter of the arm length; 19 arms 115 mm. long, the cirri 20-28 mm. long with

25-26 segments (Kei Islands; 250 meters) lisa (p. 83)

of. Arms evenly rounded dorsally, the brachials with prominent or thickened distal ends; Pj more
or less swollen basally, not much longer than the more slender and evenly tapering P3; cirri
rather long and stout, about one quarter of the arm length, with the transition segment from
the fifth to the eighth.

&'. Outer cirrus segments with a rather high transverse ridge with the crest flattened and dentate,
on the last six becoming a low subrnedian dorsal tubercle; transition segment the sixth, seventh,
or eighth; 20 arms about 90 mm. long; cirri 20-25 mm. long with 23-27 segments (Malay

Archipelago) ajax (p. 84)

b2. Outer cirrus segments with prominent and sharp dorsal spines; transition segment the fifth;
13 arms 110 mm. long; cirri 20-25 mm. long with 19^-26 segments (Hawaiian Islands; 351-
643 meters) fisheri (p. 86)

PARAMETRA COMPRESSA (P. H. Carpenter)

PLATE 8, FIGURE 26

Antedon compressa P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 222
(description; Challenger station 192 [the specimen from station 201 = P. granulata]), pi. 41, figs.
843803—50 6

66 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

1-4. — BELL, Proc. Zool. Soc. London, 1894, p. 401 (comparison with A. moorei). — HAMANN,
Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — HART-
LAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 309 (in Spinifera group; history). —
A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 34 (of P. H. Carpenter, 1888 = Parametra
compressa); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 81 (of P. H. Carpenter, 1888 = P.
compressa + P. granulata).

Charitometra compressa A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed);
Proc. Biol. Soc. Washington, vol. 21, 1908, p. 125 (should have been referred to Thalassometra) .

Thalassometra compressa A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 125 (at first
wrongly referred to Charitometra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (comparison with
Th. [Parametra] fisher i; systematic position).

Parametra compressa A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 16 (listed); Crinoids
of the Indian Ocean, 1912, p. 34 ( = Antedon compressa P. H. Carpenter, 1888), p. 213 (synonymy;
range, in part [excluding Philippine Islands]); Smithsonian Misc. Coll., vol. 61, No. 15, 1913,
p. 45 (published references to specimens in the B. M.; Challenger station 192; characters of the
division series and lower brachials); Unstalked crinoids of the Siboga-T£,\ped. 1918, p. 158 (in
key; range; references; detailed description; station 302), p. 276 (listed). — GISLEN, Ark. Zool.,
vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 33 (notes).

Diagnostic jeatures. — The arms beyond the proximal more or less oblong brachials
are distinctly carinate; the cirri are short, about one-fifth of the arm length, with the
transition segment the eighth and the distal segments broader than long with promi-
nent carinate processes or blunt dorsal spines; and the lateral portions of the elements
of the division series and first two brachials are smooth. The 15-20 arms are 120-140
mm. long, and the cirri are 23 mm. long with 16-20 segments.

Description. — The centrodorsal is discoidal with a bare flat polar area 3.5 mm. in
diameter.

The cirri are XIV, 18-20, 23 mm. long. The first segment is very short, those
following gradually increasing in length to the fourth, which is slightly broader than
long, and the fifth-seventh, which are as long as, or very slightly longer than, broad.
The eighth, a transition segment, is about half again as long as the median width.
The ninth is about as long as the median width. The following segments gradually
decrease in length so that the last three or four before the penultimate are about twice
as broad as long. The distal dorsal edge of the eighth is thickened ; on the segments
succeeding this thickening soon becomes a thick rounded dorsal spine of the type
characteristic of the genus.

The ends of the basal rays are visible as small but prominent rounded tubercles in
the angles of the calyx.

The radials are concealed. The IBr! are very short, about twice as long on the
lateral border as in the median line, in lateral apposition for the basal two-thirds but
in the distal third diverging in nearly a straight line, extending well up in the angles of
the calyx; they bear a low blunt median carination. The IBr2 (axillaries) are rhombic,
twice as broad as long, the lateral angles in contact with those of their neighbors ; the
cutting away of the distal angles of the IBri forms large and conspicuous water pores
just beneath the apposed angles of the axillaries; in the median line of the axillaries
there is a low blunt median carination ; from the lateral angles a horizontal ridge runs
inward for from one-third to one-half of the distance to the median line, sometimes in
the middle of the angle, sometimes toward the proximal side, where it branches, one
branch curving downward and becoming a produced proximal border which runs to

A MONOGRAPH OF THE EXISTING CRINOIDS 67

the median carination, the other branch running as a thickened rim along the distal
faces of the axillary, or as a ridge just within the distal edges, sometimes meeting just
proximal to (he distal apex, though usually forming a broad curve beyond which is the
apex. The IIBr series are 2. The, proximal and distal edges of the elements of the
IIBr series arc moderately thickened and everted; there is a slight rounded median
carination; the axillaries have thickened distal edges and produced proximal edges, the
latter running in a broad curve in the central part of the segment, in the lateral third
or fourth running nearly or quite straight to the lateral angle.

The edges of the first two brachials are modified like those of the elements of the
IIBr series; there is a trace of a median carination.

PI is 10-12 mm. long with 17-21 segments which, at first short, become about as
long as broad on the sixth, and nearly twice as long as broad terminally. The pinnule
is evenly tapering, rather strongly prismatic, and but little enlarged; the second-fifth
segments are sharp distally, though not distinctly cnrinate; the outer segments have the
distal angles rather prominent, though not produced. P2 is 6.5 mm. long with 12
segments, shorter, more slender, and slightly less tapering than PI. The pinnule is
strongly and sharply prismatic, the profile of the prismatic angle on the outer segments
being slightly convex; the distal segments have slightly prominent distal angles. P3
is 6 mm. long with 12 segments, similar to P2 but tapering slightly more rapidly dis-
tally. The following pinnules resemble P3. The distal pinnules are slender, 9 mm. long
with 17 segments.

Notes. — The preceding description is based upon the specimen from Siboga station
302. Carpenter's original description, based upon two specimens from Challenger
station 192 and one from Challenger station 201 (the last representing P. granulata) was
as follows:

The centrodorsal is a thick convex plate with the dorsal pole free.

The cirri are XV-XX, about 20; a few of the segments are longer than wide, and
the latter are somewhat compressed laterally, with blunt dorsal spines.

The radials, and sometimes parts of the IBr,, are concealed. The IBrj are short
and sharply convex with a slight median ridge, and they meet one another laterally
beyond the angles of the centrodorsal. The IBr2 (axillaries) are short and widely
rhombic, also with a median ridge, and forming a small tubercle with the preceding
ossicles. The IIBr series are 2, with a faint median ridge; the axillaries are short and
widely rhombic. The outer sides of the IBr axillaries, the elements of the IIBr series,
and the first two brachials are slightly flattened, and the inner sides of the second
brachials and the first syzygial pairs arc also somewhat flattened.

The 15-20 arms arc 140 mm. long and are composed of 150 or more brachiids,
of which the lowest are nearly oblong with indications of a dorsal keel and raised distal
edges, and those following arc more triangular and distinctly carinate, gradually be-
coming quadrate and somewhat compressed laterally, with a tendency to overlap.

Syzygies occur between brachials 3 + 4, again from between brachials 12+13
to between brachials 13+14, and distally at intervals of from 3 to 8 (usually 5 or 6)
muscular articulations.

P1 is about 10 mm. long with about 18 short segments, the first few of which are
much wider than their successors and slightly prismatic. Pa is smaller, with the I >a ••;».!
segments more rounded and not so wide. The following pinnules diminish in size to

68 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

about the tenth brachial (P5), having fewer but relatively longer segments. Beyond
this point the length gradually increases again, and the later pinnules are slender and
delicate, with the two basal segments flattened and somewhat expanded.

The disk is 8 mm. in diameter and is well plated along the ambulacra, but the
interpalmar areas have only a few scattered granules; the brachial ambulacra and
interarticular spaces are also well plated. The side plates of the pinnule ambulacra
are fairly distinct, with intervening sacculi.

The color in alcohol is very light brown, the disk darker.

I examined the two specimens from Challenger station 192 during a visit to the
British Museum in 1910. The carination on the earlier ossicles is confined to the
axillaries and the second brachials and is rounded and inconspicuous ; the lower brachials
and the ossicles of the division series have rather strongly everted edges.

Dr. Torsten Gislen also examined these specimens. He noted that in one the
cirri are XIV, 18-20, and in the other XIV, 19-20. They have a distinct dorsal
longitudinal crest, and are arranged in 10 and 8 indistinct columns; there is a weak
single opposing spine.

The specimen from the Danish Expedition to the Kei Islands station 4 has 12
arms 65 mm. long; the cirri have 17 segments.

The specimen from the Danish Expedition to the Kei Islands station 46 has 20
arms 120 mm. long, all the IIBr series being present; the cirri have 16-19 segments.

Localities. — Challenger station 192; near the Kei Islands (lat. 5°49'15" S., long.
132°14'15" E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888;
Bell, 1894; Hartlaub, 1912; A. H. Clark, 1907, 1908, 1909, 1912, 1913; Gislen, 1928]
(2, B. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 4; 250 meters;
sand; April 3, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 46; 250 meters;
May 2, 1922 (1, C. M.).

Siboga station 302; Timor Sea (lat. 10°27'54" S., long. 123°28'42" E.); 216 meters;
sand and coral sand; February 2, 1900 [A. H. Clark, 1918] (1, Amsterdam Mus.).

Albatross station 5619; Molucca Passage; March Island (S.) bearing S. 78° E.,
7 miles distant (lat. 0°35'00" N., long. 127°14'40" E.) ; 795 meters; fine gray sand and
mud; November 27, 1909 (1, U.S.N.M., 36025).

Albatross station 5617; Dodinga Bay, Gillolo Island; Ternate Island (S. E.)
bearing S. 45° W., 7 miles distant (lat. 0°49'30" N., long. 127°25'30" E.); 239 meters;
November 27, 1909 (5, U.S.N.M., 35976).

Geographical range. — From the Timor Sea to the Kei Islands and northward to
Halmahera (Gillolo).

Bathymetrical range. — From 216 to 795 meters; all but one of the six records are
from between 216 and 256 meters.

History. — This species was originally described in 1888 by Dr. P. H. Carpenter
under the name of Antedon compressa on the basis of two specimens from Challenger
station 192 and one specimen together with fragments of a larger individual from station
201. The specimen from the latter station is herein referred to Parametra granulata
(see page 69). Carpenter said that this species is in some respects a transitional form
between Antedon (Perissometra) patula and A. (P.) flexilis on the one hand, and the

A MONOGRAPH OF THE EXISTING CRINOIDS 69

Palmata group on the other. Tho lateral flattening of the lower brarhials is scarcely
more distinct than in Antedoit (Dlchrometra) fagellata or Antedon briricuntnta (=
Lamprometra jmlmata); but Pt has prismatic lower segments and the ambulacra of (he
disk, arms, and pinnules are well plated, though the interpalmar areas of the disk are
comparatively bare. The genital pinnules are not specially distinguished, however,
except by their shortness, and their glands arc not protected by any special pavement
of plates as in Antedon (Perissometra) flexilis and A. (P.) patula, though there is an
ambulacra! skeleton above them which is less completely differentiated than in the
slender Inter pinnules. Dr. Carpenter said that the presence of blunt spines on the
later cirrus segments also distinguishes this species from A. (P.) flexilis, A. (P.) patula,
and A. (P.) robusta, all of which have very smooth cirri, and are altogether of a more
robust nature.

In my first revision of the old genus Antedon published in 1907 compressa was
assigned to the genus Charitometra. Early in 1908, in a paper on new genera and
species of unstalked crinoids, 1 remarked that compressa, which I had placed in Cltarito-
metra, should have been referred to the genus Tkalassometra. Later in the same year
in describing Thalassometra fsheri I compared it with Thalassometra compressa "of
the. Philippines." The Philippine specimens at hand represent P. granulata which at
that time I had not distinguished from compressa. Early in 1909 compressa was referred
to the new genus Parametra.

Dr. Clemens Hartlaub early in 1912 discussed the Spinifera group of Ai<ti<l<>n in
considerable detail, including in it 18 species, among them Antedon compressa. In
my memoir on the crinoids of the Indian Ocean published later in the same year I
listed Parametra compressa, giving the synonymy and range. The locality "Philip-
pines" refers to P. granulata.

In 1913 in a paper on the crinoids in the British Museum, which I had examined
in 1910, I recorded and gave notes on two specimens of Parametra compressa from
Challenger station 192 and, under the name of Parametra granulata, recorded and gave
notes on one specimen from station 201. In my report upon the unstalked crinoids of
the Siboga Expedition published in 1918 I recorded and described in detail a specimen
of Parametra compressa from station 302.

Dr. Torsten Gisl6n in 1928 published additional notes upon the two specimens in
the British Museum from Challenger station 192.

PARAMETRA GRANULATA A. H. Clark

PLATE 7, FIGURE 25; PLATE 10, FIGURES 31, 32
[See also vol. 1, pt. 2, figs. 874-878, p. 435.]

Antedon compressa (part) P. H. CARPKNTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 222
(specimen from Challenger station 201).

Thalassometra compressa A. H. CI-AKK, Smithsonian Misc. Coll., vol. 52, pt. 2, 1908, p. 227 (Albatross
station 5110).

Parametra compressa A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 406 (Albatross stations
5255, 5166); vol. 39, 1911, p. 554 (Albatross stations 5279, 5325, 5367, 5411, 5519, 5523, 5536;
specific characters) ; Crinoids of the Indian Ocean, 1912, p. 213 (in part; records from the Philip-
pine Islands).

Parametra granulata A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 4.r> (puhli-lir.l
reference to specimen in tl'c H. M.; Cl«ill<:ngcr station 201; characters of the division series and
lower brachials). — F. W. CLARKE and \\"IIEF.I.ER, U. S. Gcol. Surv. Prof. Pap. 90 D, 1914, pp.

70 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

34 and following (inorganic constituents on the skeleton); Prof. Pap. 102, 1917, pp. 102 and
following (same). — A. II. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 158 (in key;
range), p. 160 (references; station 105), p. 273 (listed). — F. W. CLARKE and \V. C. WHEELER,
U. S. Geol. Surv. Prof. Pap. 124, 1922, p. 17 (Albatross station 5536; inorganic constituents of
the skeleton).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 32 (notes).

Diagnostic features. — The arms beyond the proximal more or less oblong brachials
are distinctly carinate; the cirri are short, about one-fifth of the arm length, with the
transition segment the eighth, and the distal segments broader than long with prominent
dorsal processes or blunt dorsal spines; and the lateral portions of the division series
and first two brachials are more or less completely covered with fine tubercles. The
12-20 (usually 17-20) arms are 145-170 mm. long, and the cirri have about 20 segments.

Description. — The cirrus sockets are arranged approximately in 10 columns on the
centrodorsal. The cirri are XI, 18; the cirrus segments have a distinct longitudinal
carination.

The sides of the division series and lower brachials are more or less covered with
fine tubercles, and there is a narrow and low, though prominent, median keel which is
continued along the arm and passes into the distal carination. Weak synarthrial tuber-
cles are developed. The division series and lower brachials are considerably smoother
than those of P. compressa, as the result of the absence of the eversion of the proximal
and distal edges.

The 12-20 (usually from 17-20) arms are, in fully developed specimens, 145-170
mm. long.

Note. — The preceding description is based mainly upon the specimen in the British
Museum from Challenger station 201. The description of the cirri and the mention of
the synarthrial tubercles are taken from notes by Prof. Torsten Gisl6n, and the de-
scriptions of the division series and lower brachials are from my personal notes.

Speaking of the specimen from Challenger station 201 Dr. P. H. Carpenter said
that it differed from the two other specimens from station 192 on which he based his
Antedon (Parametra) compressa in having "much smoother joints at the bases of the
arms, their distal edges being but little raised; while in some fragments of a larger form
obtained at the same locality there is a tendency to expansion in the third and fourth
joints of some of the genital pinnules, which recalls their condition in Antedon (Perisso-
metra) flexilis. The interpalmar areas of the disk are also more plated than in the
example from Station 192."

The specimen from Siboga station 105 is small with 10 arms about 35 mm. long;
the cirri have 15 segments of which the fourth is a transition segment.

Dr. Gislen says that this form seems to be a variety of P. compressa, a statement
with which I agree.

Localities. — Albatross station 5166; Tawi Tawi group, Sulu (Jol6) Archipelago;
Observation Island bearing N. 20° W., 4.6 miles distant (lat. 4°56'10" N., long.
119°46'00" E.); 177 meters; coral sand; February 24, 1908 [A. H. Clark, 1909] (1,
U.S.N.M., 35607).

Albatross station 5576; north of Tawi Tawi; Mount Dromedario bearing S. 22° W.,
17.2 miles distant (lat. 5°25'56" N., long. 120°03'39" E.); 506 meters; bottom temper-
ature 11.8° C.; sand; September 22, 1909 (1, U.S.N.M., 35955).

A MONOGRAPH OF THE EXISTING CRIXOIDS 71

Siboga station 105; Sulu (Jol6) Sea (lat. 6°08' N., long. 121 °19' E.); 275 meters;
coral bottom; July 4, 1899 [A. H. Clark, 1918] (1, Amsterdam Mus.).

Challenger station 201; off Mindanao (lat. 7°03' N., long. 121 °48' E.); 150 meters;
stones and gravel; October 26, 1874 [P. H. Carpenter, 1888; A. H. Clark, 1913; Gislen,
1928] (1, B. M.).

Albatross station 5255; Gulf of Davao; Dumalag Island (S.) bearing S. 65° W., 4.5
miles distant (lat, 7°03'00" N., long. 125°39'00" E.); 183 meters; soft mud; May 18,
1908 [A. H. Clark, 1909] (1, U.S.N.M., 35606).

Albatross station 5519; in the vicinity of northern Mindanao; Point Tagolo light
bearing S. 71° W., S.7 miles distant (lat. 8°47' N., long. 123031'15" E.);33:i meters;
bottom temperature 12.4° C.; globigerinae and sand; August 9, 1909 [A. H. Clark,
1909] (2 U.S.M.N., 35603).

Albatross station 5523; in the vicinity of northern Mindanao; Point Tagolo light
bearing S. 48° W., 6.7 miles distant (lat. 8°48'44" N., long. 123°27'35" E.); no depth
given; August 10, 1909 [A. H. Clark, 1909] (1, U.S.N.M., 35609).

Albatross station 5536; between Negros and Siquijor; Apo Island (C.) bearing S.
26° W., 11.8 miles distant (lat. 9°15'45" N., long. 123°22'00" E.); 510 meters; bottom
temperature 11.9° C.; green mud; August 19, 1909 [A. H. Clark, 1909; F. W. Clarke
and Wheeler, 1922] (7, U.S.N.M., 35604).

Albatross station 5411; between Cebu and Bohol; Lauis Point light bearing N.
35° E., 4.7 miles distant (lat, 10°10'30" N., long. 123°51'15" E.); 265 meters; bottom
temperature 12.9° C.; green mud; March 23, 1909 [A. H. Clark, 1909]; (1, U.S.N.M.,
35605).

Albatross station 5367; Verde Island Passage; Malabrigo light bearing N. 81° E.,
8 miles distant (lat, 13°34'37" N., long. 121°07'30" E.); 329 meters; sand; February
22, 1909 [A H. Clark, 1909] (5, U.S.N.M., 35601).

Albatross station 5279; China Sea in the vicinity of southern Luzon; Malavatuan
Island (W.) bearing S. 18° W., 5.4 miles distant (la't. 13°57'30" N., long. 120°22'15"
E.); 214 meters; green mud; July 17, 1908 [A. II. Clark, 1909] (2, U.S.N.M., 35602,
35954).

Albatross station 5110; China Sea off southern Luzon; Corregidor light bearing N.
20° E., 25 miles distant (lat. 13°59'20" N., long. 120°75'45" E.); 247 meters; bottom
temperature 15° C.; dark gray mud; January 15, 1908 [A. H. Clark, 1908] (2, U.S.N.M.,
35608).

Albatross station 5325; off northern Luzon; Ilermanos Island (N.) bearing N.
86° E., 16.75 miles distant (lat. 18°34'15" N., long. 121°51'15" E.) 409 meters;
bottom temperature 11.8° C.; green mud; November 12, 1908 [A. II. Chirk 1909].

Geographical range. — Philippine Islands, from the Tawi Ta\vi group northward to
northern Luzon.

Bathymetrical range. — From 150 to 510 meters; the average of 12 records is 300
meters.

Thermal range.— From 11.8° to 15.0° C.; the average of 6 records is 12.6° C.

History. — The first known specimen of this species was a young individual dredged
by the Challenger at station 201 and recorded by Dr. P. H. Carpenter under the name
of Antedon compressa in the ChnUtmjir report on tin- cnmatulids in 1888. Carpenter

72 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

briefly noted certain differences between this specimen and the two types of compressa
from station 192, and mentioned some features of fragments of a larger individual
taken with it.

In 1908 I recorded this species as Thalassometra compressa from Albatross station
5110. Under the name Parametra compressa I recorded two specimens from Albatross
stations 5166 and 5255 in 1909, and 18 specimens from stations 5279, 5325, 5367, 5411,
5519, 5523, and 5536 in 1911, giving brief notes on the latter.

In my memoir on the crinoids of the Indian Ocean published in 1912 these Philip-
pine records were included under Parametra compressa.

In 1913 under the name Parametra granulata I published a note on the specimen
from Challenger station 201 which I had examined at the British Museum in 1910,
citing certain differences between it and the two specimens of P. compressa from station
192, with which I compared it directly.

In 1914 Prof. Frank Wigglesworth Clarke and Dr. W. C. Wheeler published a
chemical analysis of the skeleton of Parametra granulata based upon material from the
Philippines which I had given them. Their analysis was republished in 1922.

In my report upon the unstalked crinoids of the Siboga expedition published in
1918 I inserted granulata in a key to the species of Parametra and recorded and gave
notes on a young specimen from station 105.

In 1928 Prof. Torsten Gislen gave additional notes on the Challenger specimen
from station 201 which he had examined in London.

PARAMETRA ORION (A. H. Clark)

PLATE 5, FIGURES 19, 20; PLATE 8, FIGURE 27; PLATE 10, FIGURE 30

[See also vol. 1, pt. 1, figs. 4, p. 63, 18, p. 67, 201, 202, p. 239, 270, p. 259, 489, p. 365; pt. 2, figs. 217,

p. 163, 251, p. 199, 745, p. 349.]

Antedon orion A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 143 (description; Albatross
station 4934) ; vol. 34, 1908, p. 486.

Charitometra orion A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed); Proc.
Biol. Soc. Washington, vol. 21, 1908, p. 125 (should have been referred to Thalassometra).

Thalassometra orion A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 125 (at first wrongly
referred to Charitometra); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (comparison with Th.
[Parametra} fisheri; systematic position), p. 226 (comparison with Th. [Cosmiometra] delicata),
p. 310 (Sagami Bay).

Parametra orion A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 16 (listed) ; Vid. Medd.
Naturhist. Foren. K0benhavn, 1909, p. 187 (Eastern Sea near Nagasaki, 170 fathoms; descrip-
tion of the specimen); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 554 (between Fracas [Pratas] reef
and Formosa; compared with P. compressa) ; Crinoids of the Indian Ocean, 1912, p. 213(synonymy;
range) ; Proc. Biol. Soc. Washington, vol. 26, 1913, p. 182 (south of the Goto Islands, 124 fathoms) ;
Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and
its significance); Unstalked crinoids of the Siboga-'Exped., 1918, p. 158 (in key; range), p. 160
(references). — MORTENSEN, Studies in the development of crinoids, 1920, p. 4 (size of eggs).

Perissometra aranea GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 5
(200 meters), p. 6 (Kiu Shiu and Goto Islands), p. 120 (station 7a; detailed notes), p. 180 (listed),
figs. 103, 104, p. 122; Zool. Bidrag Uppsala, vol. 9, 1924, p. 285 (Kiu Shiu; 198 meters; details);
Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 83, 1927, p. 2 (station 7; 198 meters), p. 33
(station 7; notes), p. 34 (compared with P. carinata), p. 68 (listed), fig. 23, p. 27; Ark. Zool., vol.
19, No. 32, Feb. 20, 1928, p. 8; Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 93, 1933,
p. 481.

A MONOGRAPH OF THE EXISTING CRINOIDS 73

Monachometra cf.fragilis GISL£N, Zool. Bidrag Uppsala, vol. 9, 1924, pp. 44, 51; fig. 14, p. 48 (base of
a postradial series).

Perissomelra cf. aranea GISL£N, Zool. Bidrag Uppsala, vol. 9, 1924, p. 80 (note on syzygial faces).

Perissometra carinata GisLfin, Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 83, 1927, p. 2
(station 9; 162 meters), p. 34 (station 9; description; comparisons), p. 68 (listed), figs. 24, 25, p. 37,
pi. 2, fig. 84; Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 93, 1933, p. 481.

Monachometra mortenseni GISL£N, Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 83, 1927, p. 2
(station 9; 162 meters), p. 35 (station 9; description; comparisons), p. 68 (listed), figs. 26, 27, p. 37,
pi. 1, fig. 83; Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 93, 1933, p. 481.

Monachomelra fragilis Gisi.fiN, Vid. Medd. Dansk Nalurh. Foren. K0benhavn, vol. 83, 1927, p. 38
(comparisons); Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 21.

Diagnostic features. — The arms beyond the proximal more or less oblong brachials
are distinctly carinate; the cirri arc short, about one-fifth of the arm length, with usually
20-25 segments of which the eighth is a transition segment and the distal are broader
than long with strong carinate processes or blunt dorsal spines; and the lateral portions
of the division series and first two brachials may be unmodified or more or less exten-
sively irregularly tubercular, with or without a fine median raised line. The 10-18 arms
are 125-140 mm. long, and the cirri are 20-25 mm. long.

Description of the type specimen. — The centrodorsal is a thick disk with the flat
and somewhat roughened dorsal pole broad, 4 mm. in diameter and the sides practically
vertical. The cirrus sockets arc arranged in 15 closely crowded columns of one or two
each.

The cirri are XXI, 15-25, from 20 to 25 mm. long, almost or quite straight in the
proximal third and strongly and regularly recurved in the distal two-thirds so that the
extreme tip is parallel with the basal portion. In a fully developed cirrus the first
segment is very short, in some cases only the dorsal half projecting beyond the cirrus
socket; the second is about three times as broad as long, the proximal border with a
strong broadly rounded median angle and the distal border concave; the third is about
twice as long as the greatest (midlateral) length with the proximal and distal borders
as in the preceding though with the curvature somewhat less pronounced; the fourth is
half again as broad as long; the fifth is about as long as, or slightly longer than, broad;
the sixth is slightly longer; the seventh is about one-third again as long as broad; and
the eighth, a transition segment, is twice as long as the median width. The transition
segment, usualty the eighth though often the seventh, is basally slightly less in width
than the distal end of the segment preceding; it tapers markedly in the proximal two-
thirds, in the distal third increasing slightly in width; the proximal two-thirds has a
dull surface like that of the segments preceding but is darker in color; the distal third
is very light with a polished surface like the following segments. The cirri arc stout
at the base but taper rather abruptly on the transition segment so that the portion
beyond that segment is in lateral view only about three-quarters the width of the basal
portion. The segments immediately following the transition segment are more or less
longer than broad, but after one or two they become slightly broader than long. These
segments have a median dorsal carination which at first is rounded but soon becomes
sharp. In lateral view the profile of the dorsal surface of these segments rises in a
curved convexity from the proximal to the distal end so that the distal end projects
beyond the base of the segment next following and may sometimes be produced into a
short sharp point. The opposing spine is represented by a low subterminal elevation

74 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

involving the entire dorsal surface of the penultimate segment; this is usually more or
less broadly rounded, rarely pointed. The terminal claw is usually about as long as the
penultimate segment and is stout, rapidly tapering, moderately curved, and usually
with a blunt tip.

The ends of the basal rays are visible as small more or less irregular tubercles in
the interradial angles beneath the inverted V formed by the narrow lateral ends of
adjacent radials.

The radials are concealed by the centrodorsal except for the narrow lateral ends
that meet above the ends of the basal rays. Narrow and shallow slitlike subradial
clefts are present. The IBrj are short and bandlike with the proximal and distal borders
slightly curved and parallel and the lateral ends in apposition with those of their neigh-
bors on either side. The IBr2 (axillaries) are short, about three times as broad as long,
rhombic with pointed or slightly truncated angles, and in lateral apposition. The
IIBr series, which are 2, resemble the IBr series but are somewhat longer. The
proximal and distal borders of the ossicles of the division series may be slightly and
broadly thickened, but there is no trace of a median carination or other modification
of the surface. The dorsal surface is moderately convex.

The 13 arms are about 125 mm. long. The first brachials are short, about four
times as broad as long, slightly longer exteriorly than interiorly, with the proximal and
distal borders straight and almost parallel. They are interiorly united for their whole
length and externally are in contact with their neighbors against which they are rather
narrowly flattened. The second brachials are larger than the first, irregularly quadrate
or triangular with the inner side reduced to a point and the proximal border rather
strongly curved. The first syzygial pair (composed of brachials 3+4) is oblong,
usually about twice as broad as long, with the hypozygal and epizygal of the same size.
The next five or six brachials are oblong, about three times as broad as long, those
succeeding becoming wedge-shaped and soon almost as long as broad, remaining of the
same proportions until the terminal portion of the arm, where they become somewhat
elongated. The oblong brachials at the base of the arm are slightly constricted cen-
trally and there is a slight suggestion of indistinct broad and low articular tubercles,
so that this portion of the arm appears somewhat irregular and rugose. There is no
trace of carination or other ornamentation of the dorsal surface. On about the twelfth
brachial the middorsal portion becomes elevated in a V-shaped area with a rounded
summit, the apex of the V being in the middle of the proximal border and the narrow
side, which is finely serrate, on the distal border. At first these V-shaped elevations
alternate on either side of the median line, but they soon become aligned along the mid-
dorsal line of the arm. The arm now becomes compressed laterally, after about the
proximal third becoming narrow and high with a conspicuous narrowly rounded median
carination which is higher on the distal than on the proximal ends of the brachials so
that the arm appears serrate in lateral view.

Syzygies occur between brachials 3+4 and 13 + 14 or 14+15, and distally at
intervals of from 6 to 12 muscular articulations.

PI is 6.5 mm. long with 15 segments, only slightly larger than the pinnules follow-
ing, tapering evenly and regularly from the base to the tip. The first segment is some-
what broader than long, those following slowly increasing in length, becoming as long
as broad on the sixth or seventh and somewhat longer than broad distally. The pinnule

A MONOGRAPH OF THE EXISTING CRINOIDS 75

is somewhat flattened exteriorly; the segments have finely serrate distal edges and the
distal outer angle may be somewhat produced. P2 resembles PI but is slightly shorter
and less stout. The pinnules following decrease gradually in length to about P6, which
is 4 mm. long with 9 segments, all broader than long except the last two. The genital
pinnules increase slowly in width from the base to the third segment, thence tapering
to the tip, the second and third, or second- fourth segments being slightly broadened.
The distal pinnules are more slender, 7 or 8 mm. long with 18 segments, all of which are
about as long as broad and very sharply carinate.

The disk is moderately or well plated, and the ambulacra are well plated. Sacculi
are abundant on the pinnules.

ATotes. — In other specimens from the type locality the proximal, distal, and lateral
borders of the elements of the IBr series and the lateral borders of the IIBr series may
be more or less extensively irregularly tuberculate, this tuberculation sometimes
involving the entire dorsal surface of the IBrj, and some specimens show a very distinct,
though low and narrow, middorsal line on the division series and on all the brachials
of the proximal portion of the arms.

Gislen's original description of Perissometra aranea based upon a single specimen
from Bock's station 7a is as follows: The centrodorsal is a low cone 2 mm. in diameter,
dorsally with a central cavity and small side cavities. The cirrus sockets are arranged
in 10 columns, one or two in each column.

The cirri are XIV, 17-21, 10-11 mm. long. The first-third segments are broader
than long, the fourth is somewhat longer, the fifth is half again as long as broad, and the
sixth is twice, as long as broad, distally a little widened and with an inconspicuous
dorsal spine. The segments following are shorter, each with a dorsal spine. From
about the ninth the segments are about as long as broad; the antepenultimate is half
again as long as broad. The opposing spine reaches a height of about one-fifth of the
penultimate segment. The terminal claw is curved and is somewhat longer than the
segment preceding.

The radials are in the form of narrow bands, almost concealed. The IBri are
four times as broad as long with a low median carination and are in lateral contact.
The IBr2 (axillaries) are pentagonal, three times as broad as long, with a similar low
longitudinal tubercle. There is a slight thickening of the distal border, the rest of the
ossicle being smooth. It is laterally flattened like the IBr^

The 10 arms are 70 mm. long. The first two brachials have a carination similar
to that on the IBr series but very much slighter. The first brachials are internally
contiguous in pairs, externally broader (longer), as are also the second brachials. The
proximal brachials are rounded and smooth. The first 10 brachials are discoidal,
those following irregularly oblique. From the fifteenth onward there is a low median
longitudinal crest slightly projecting in lateral profile.

Syzygies occur between brachials 3 + 4, 13 + 14, 18+19, and distally at intervals
of about 5 oblique muscular articulations.

PI is 5 mm. long with 13 segments. Pa is also 5 mm. long with 13 segments. Pj
is 3.5 mm. long with 8 or 9 segments. P8 is similar. PI is coarser than P2. The seg-
ments of these pinnules are rather uniform, smooth, a little longer than broad, distally
somewhat angular. P4 to PJ2 are 3—4 mm. long with about 10 segments of which the
proximal are very slightly flattened clorsoventrally. The distal pinnules arc 5-6 mm.

76 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

long with about 14 segments of which the first and second are shorter and a little coarser
than those following, which are twice as long as broad.

The disk is a little incised with large calcareous granules, 4 mm. in diameter.

The color is light yellow-brown, the disk brown.

Gislen said that after comparison with specimens from Dr. Mortensen's collection
he is convinced that this species often has 11 or 12 arms up to 70 mm. long. The IIBr
series are 2. PI may have 15 segments and reach a length of about 6 mm. P2 to Pto
are short with the five or six proximal segments somewhat thickened in dorsal view.

He remarked that in the short genital pinnules the species has an unusual resem-
blance to a spider, hence the name.

In 1927 Professor Gislen published notes on the specimens from Mortensen's
station 7 to which he referred in the original description. Of the first specimen he said
that the centrodorsal is almost hemispherical, 3.0 mm. in basal diameter and 2.0 mm.
across the slightly convex dorsal pole. The cirrus sockets are arranged hi 10 columns,
1 or 2 to a column.

The cirri are XIII, 19-22, from 13 to 15 mm. long. The sixth or seventh is a
transition segment, three-quarters again as long as the distal width, with the first
dorsal spine protruding from the distal part.

The IBri are five times as broad as long with a well delimited median carination
which continues on to the proximal part of the IBr2 (axillary). The IIBr series are 2.
The ossicles of the IBr and IIBr series have a slightly everted proximal border and two
or three small pits on each side of the low median carination.

The 1 1 arms are 70+ mm. long. The low median carination on the division series is
continued out to the distal parts of the arms. The distal brachials have slightly everted
distal borders and a rather strong median carination.

The distal intersyzygial interval is from 4 to 9 (usually 5 or 6) muscular
articulations.

PI is 6.5 mm. long with 13-14 segments. P2 is 4 mm. long with 8-10 segments.
P3 is 3 mm. long with 7-9 segments. P4 is 3 mm. long with 7 segments. P7 is 4 mm.
long. The distal pinnules are 8 mm. long with 18 segments. The disk is 5 mm. in
diameter.

In a second specimen from the same station the cirri are XVII, 22-23, 13-16 mm.
long, in 11 columns. The 12 arms are 70+ mm. long. The dorsal carination is as in
the preceding specimen. PI is 5 mm. long with 14-16 segments. P2 is 4.5 mm. long
with 11 segments. P4 is 3.7 mm. long with 10 segments. The disk is 5 mm. in diameter
and bears coarse granules. The anal cone is 1.5 mm. high.

A third specimen from the same station has the cirri XVI, 18-23, from 10 to 12 mm.
long, arranged in 10 columns. The arms, which are partly broken, were at least 11,
and arc 60 mm. long. PI is 4.5 mm. long with 12 segments. P3 is 2.5 mm. long with
7 segments. The distal pinnules are 6 mm. long with 12 segments of which the longest
are from two to two and one-half times as long as broad.

In his original description Gisl6n said that this supposed new species most closely
resembles Glyptometra lata from which, however, it differs sharply by the cirri, very
short in comparison with the arm length, but in spite of this with relatively many seg-
ments; by the rather smooth proximal arm parts; and, above all, by the proximal pin-
nules which have few and rather long segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 77

Later he said that by the low median dorsal carination of the arms this species
approaches Chondrometra rugosa and Glyptometra tuberosa. From the species first
mentioned it is, however, easily distinguished by much smaller size, by a low centro-
dorsal carrying only XIII-XX cirri, and by more cirrus segments, though the cirri arc
only half as long as those of Chondrometra rugosa. It differs from Glyptometra tuberosa
in having more cirrus segments which are provided, besides, with small but distinct
dorsal spines, by smoother arm bases, by PI having much fewer segments, and by the
smaller size.

The description of the cirri and of the relation between PI and P2 show that these
specimens belong to a species in the family Thalassometridae, not in the family Charito-
metridae, and they are quite indistinguishable from specimens of Parametra orion of
corresponding size.

Gislen described Perissometra carinata as follows: The centrodorsal is conical,
3 mm. broad at the base and 3 mm. high, with distinct interradial crests. The cirrus
sockets are arranged in 10 columns.

The cirri are XXI, 20-21, about 15 mm. long. The fourth segment is slightly
longer than broad; the sixth segment is half again as long as the distal width and is a
transition segment; from the distal part of this segment the segments are polished and
are provided with a dorsal spine. This dorsal spine is peculiar in appearance, as from
the eighth segment it transforms into a strong longitudinal carination, a notch occurring
between the carination of two successive cirrus segments. The segments from the
eighth to the penultimate are one-third again as broad as long. The opposing spine is
small but distinct. The curved terminal claw is about equal to the preceding segment
in length.

The radials are concealed. The IBr, are four times as broad as long, free laterally
though close to their neighbors, with sharp distolateral angles. There is a well defined
median crest and on each side of the median line a couple of indistinct pits. The IBra
(axillaries) are three times as broad as long, pentagonal, with a raised and slightly
spiny proximal border; there is a sharp median carination in the proximal two-thirds.
The IIBr series are 2, and have a median carination similar to that on the IBr series.

There are at least 12 arms (one postradial series is broken) 65 mm. long. The
proximal portion of the postradial series is not flattened laterally. The carination
continues dorsally out to the distal portion of the arms, which is slightly compressed
laterally. The brachials as far as the tenth are discoidal. The width of the proximal
portion of the arms is 1.7 mm. The distal brachials are slightly thickened at their
distal ends.

In three cases out of ten the first syzygy (between brachials 3+4) is replaced by a
synarthry. The distal intersyzygial interval is 7 or 8 oblique muscular articulations.

PI is 6 mm. long with 14-15 segments which are squarish and slightly prismatic. Ps
is 4.4 mm. long with 11-12 segments. P6 is 3.2 mm. long with 7 segments. The distal
pinnules are 6.2 mm. long with about 16 segments. '

The disk has been lost.

In another specimen the centrodorsal is 1.8 mm. broad at the base and 1.2 mm.
high. The cirri are partly broken. The dorsal carination is weaker than in the speci-
men just described, more protruding in the distal part of the segment. The radials are
six times as broad as long. The IBrt are three times as broad as long, with a weak

78 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

carination. The IBr2 (axillaries) are two-fifths as long as broad with a carination in the
proximal part, but otherwise smooth. The 11+ partly broken arms are about 30
mm. long.

Professor Gisle'n said that this species is very similar to P. aranea, differing in the
more distinctly conical centrodorsal and above all by the carination of the distal
cirrus segments.

The two chief diagnostic features given in the description are, first, the occurrence
of a transition segment in the cirri beyond which is a series of highly polished spine-
bearing segments; and, second, the shortness of P2 as compared with PI. These features
indicate that these specimens belong to a species of Thalassometridae, not to a species
of Charitometridae. Taken in connection with other characters given, especially the
compression and carination of the outer portion of the arms, they place the specimens
in the genus Parametra, in which genus they show no features by which they may be
distinguished from P. orion, of which they are undoubtedly only small individuals.

Professor Gislen gave no formal description of Monachometra mortenseni, contenting
himself with notes on 12 specimens from Mortensen's station 9, the station from
which came the type specimen of his Perissometra carinala. (1) The centrodorsal
is a thick disk 3 mm. in diameter with the free dorsal pole flattened and 2.5 mm. in
diameter. The cirri are arranged in an almost simple row and in 15 columns. The
cirri are XVI, 17-19, 12 or 13 mm. long. The third segment is about as long as broad
and the sixth or seventh are the longest, half again as long as the distal breadth; the
outer part of this segment is polished and like the following segments is provided with
a weak dorsal prominence in the distal part. The opposing spine is small but distinct
and unforked. The radials are concealed. The IBr! are six times as broad as long.
The IBr2 (axillaries) are two-fifths as long as broad and like the IBrj have a weak
median longitudinal carination; the proximal and distal borders are slightly raised.
The 1 1 arms are 55 mm. long. The IIBr series are 2. The proximal parts of the arms,
though closely set, are not wall-sided. There is a very weak and indistinct carination
out to the distal parts of the arms. Syzygies occur between brachials 3+4 and 13+14
and distally at intervals of from 6 to 10 muscular articulations. PI is 5 mm. long with
11-13 segments. P2 is 2.8 mm. long with 8 segments. P6 is 2.3 mm. long with 7
segments. The distal pinnules are 5.2 mm. long with 14-15 segments. The disk is 4.3
mm. in diameter and is coarsely granular. The anal cone is short, 1.3 mm. high.
The color is banded yellow-brown, the dorsal pole of the centrodorsal darker.

(2) The diameter of the centrodorsal is 3 mm. The cirri are XV, 18-20, from
10-13 mm. long. The arms are 13 + , 55 mm. long. They are partly broken and
probably were 16 when the specimen was complete; four rays have 3, 3, 3, and 4 arms.
The median carination is indistinct. Pt is 5 mm. long with 13 segments. P2 is 3.7 mm.
long with 9 segments. P3 is 2.8 mm. long with 7 segments. P6 is 2.5 mm. long with
7 segments. The distal pinnules are 4.5 mm. long with 11 segments.

(3) The diameter of the centrodorsal is 2.8 mm. The cirri are only XIII, 18,
about 11 mm. long. The arms are 11, 75 mm. long; the IBrj is eight times as broad
as long. The proximal portions of the arms are 1.2 mm. in breadth. PI is 6.2 mm.
long with 16 segments. P3 is 3.2 mm. long with 8 segments.

(4) The diameter of the centrodorsal is 3.5 mm. The cirri are XV, 21-23, from
13 to 18 mm. long in 14 columns. The 12 arms (perhaps 13 when the specimen was

A MONOGRAPH OF THE EXISTING CRINOIDS 79

complete) are broken. The breadth of the proximal portion of the arms is 1.7 mm.
The intersyzygial interval is from 4 to 11 muscular articulations. Pj is 8.2 mm. long
with 15 segments. P2 is 5.8 mm. long with 14 segments. P3 is 4.8 mm. long with 11
segments. P7 is 3.8 mm. long with 9 segments.

(5) The 13 arms have full-grown regenerates of brighter color than the proximal
portions. This specimen was attached to a sponge.

(6) The cirri are in 14 columns. They are XV, about 20, about 12 mm. long.
The 12 arms are 60 mm. long. P! is about 5 mm. long with 14 segments. P3 is 2.4
mm. long with 8 segments. The distal pinnules are 4.5 mm. long with 12 segments.
The disk has coarse granules along the ambulacral furrows.

(7) The diameter of the centrodorsal is 3.2 mm. The cirri are XV, 21, about 13
mm. long. The 18 arms are all broken. The disk is 6.5 mm. in diameter and is plated
with coarse granules.

(8) The cirri are in 15 columns and are XV, 21-22. The 13 +arms (on three post-
radial series 3, 3, 3) are 65 mm. long. P] is 6 mm. long with 16 segments. P2 is 3.3
mm. long with 9 segments. P4 is 2.8 mm. long with 6 segments.

(9) The cirri are XV, about 20. The 15 arms are 55 mm. long. PI is 6 mm. long
with 16 segments. P2 is 3 mm. long with 9 segments. The distal pinnules are 5 mm.
long with 1 1 segments.

(10) The diameter of the centrodorsal is 2.8 mm. The cirri are XIV, 20-23.
The arms are at least 13, 60 mm. long. The diameter of the disk is 4.8 mm. This
is a 6-rayed specimen.

(11 and 12) These specimens are dried; they have 11 and 12 arms.

Gislen said it seemed to him that with the present limitation of the genera within
the Charitometridae one must refer this species (mortenseni) to Monachometra. The
only species previously referred to this genus, M. fragilis, differs sharply from M.
mortenseni. He noted I had informed him that the opposing spine is double in M.
fragilis, as in Diodontomelra. From this genus it is distinguished by the totally
different appearance of the centrodorsal. Monachometra mortenseni has a simple
opposing spine, and besides dorsal spines, which are absent in M. fragilis, other
differences are: In M. mortenseni the cirri are XV, about 20, about 13 mm. long,
whereas in M. fragilis the cirri are XXX, 17-18, from 30 to 35 mm. long. In M.
mortenseni the arms are about 15, from 55 to 75 mm. long, not wall-sided, whereas in
M. fragilis they are 19, 145 mm. long, and strongly wall-sided. In M. mortenseni
PI is 5 mm. long with about 14 segments; P2 is about 3 mm. long with about 10 seg-
ments; P3 is about 3 mm. long with about 8 segments, whereas in M. fragilis PI is 9 mm.
long with about 30 segments; P2 is about 10 mm. long with 25 segments; and P3 is
11 mm. long with 22 segments. The largest and stoutest specimen of M. mortenseni
(specimen 4) only slightly surpasses these figures. In the Uppsala Museum there
is a specimen of M. fragilis which has permitted direct comparison; it has 20 arms
130 mm. long.

Gislen added that the two species of the genus Monachometra are surely not closely
related. Nevertheless they must be provisionally ranged in the same genus which
will, perhaps, not be possible in the future, as the classification of the Charitometridae
is still not completely satisfactory.

80 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The figures of the cirrus and of the earlier brachials with PI and Pj given by
Professor Gislen are typical of Parametra orion, and there is nothing in the descriptions
of the specimens to indicate that his specimens do not belong to this species.

The specimen from near Nagasaki hi 311 meters has 14 arms 130 mm. long, and
XV cirri 20 mm. long arranged in a single marginal row.

The specimen from south of the Goto Islands in 223 meters has 15 arms 125 mm.
long and the cirri XVIII, 23-24, from 21 to 23 mm. long.

It was from one of these two specimens that Dr. Mortensen secured the eggs,
which he found to be 0.15 mm. in diameter.

In this species the arms vary from 10 to 18 in number and reach a length of 140 mm.
In fully developed individuals the cirrus sockets are arranged in 15 columns on the
centrodorsal, but in small ones there are commonly only 10 columns.

Localities. — Albatross station 5306; China Sea, near Pratas reef (lat. 20°55'00" N.,
long. 116°40'00" E.); 306 meters; bottom temperature 10.78° C.; coral and sand;
October 26, 1908 [A. H. Clark, 1911, as "Between Pracas Keef and Formosa," 1912,
1915, 1918] (3, U.S.N.M., 35618).

Dr. Sixten Bock's Expedition to Japan 1914; station 7a; 23 miles northwest of the
Goto Islands (lat. 32°17' N., long. 128°11' E.); 201 meters; May 14, 1914 [Gislen, 1922].

Dr. Th. Mortensen's Pacific Expedition 1914-16; station 7; 23 miles northwest of
the Goto Islands (lat. 32°17' N., long. 128°11' E.); 201 meters; sand; May 14, 1914.
This is the same station as Bock's station 7a; Drs. Bock and Mortensen were working
together at this time [Gislen, 1922, 1924, 1927].

Dr. Th. Mortensen's Pacific Expedition 1914-16; station 9; near the Goto Islands
(lat. 32°15' N., long. 128°12' E.) ; 162 meters; hard bottom; May 15, 1914 [Gislen, 1927].

Albatross station 4904; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 27° E., 6 miles distant (lat. 32°31'20" N.,
long. 128°32'40" E.); 192 meters; fine gray sand and broken shells; August 10, 1906
[A. H. Clark, 1912, 1915, 1918] (1, U.S.N.M., 35622).

Albatross station 4903; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 22° E., 6 miles distant (lat. 32°31'10" N.,
long. 128°33'20" E.); 192-250 meters: bottom temperature 11.61° C.: gray sand and
broken shells; August 10, 1906 [A. H. Clark, 1912, 1915, 1918] (2, U.S.N.M., 35567).

Albatross station 4901; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 9° E., 6.5 miles distant (lat. 32°30'10" N.,
long. 128°34'40" E.); 250 meters; bottom temperature 11.61° C.; gray sand and broken
sheUs; August 10, 1906 [A. H. Clark, 1912, 1915, 1918] (1, U.S.N.M., 35621).

Albatross station 4902; Eastern Sea, between 10 and 20 miles southwest of the
Goto Islands; Ose Saki Light bearing N. 10° E., 6 miles distant (lat. 32°30'50" N.,
long. 128°34'40" E.); 250 meters; bottom temperature 11.61° C.; gray sand and broken
shells; August 10, 1906 [A. H. Clark, 1912, 1915, 1918] (1, U.S.N.M., 35619).

Eastern Sea, near Nagasaki (lat. 30°22' N., long. 128°42' E.); 311 meters; Cap-
tarn Suensson, November 11, 1901 [A. H. Clark, 1909, 1912, 1915, 1918] (1, C. M.).

Eastern Sea, south of the Goto Islands Gat. 32°25' N., long. 128°52' E.); 223
meters; bottom temperature 12.78° C.; Captain Suensson [A. H. Clark, 1913, 1915,
1918] (1, C. M.).

A MONOGRAPH OF THE EXISTING CRINOIDS 81

Albatross station 4888; Eastern Sea, about 20 miles southwest of Nagasaki En-
trance; Nomo Zaki bearing N. 57° E., 16.5 miles distant (lat. 32°26'00" N., long.
129°27'30" E.) ; 128 meters; bottom temperature 15.39° C.; dark gray sand and broken
shells; August 8, 1906 [A. H. Clark, 1912, 1915, 1918] (3, U.S.N.M., 35623).

Albatross station 4934; Eastern Sea, off Kagoshima Gulf; Sata Mistiki Light
bearing N. 77.5° E., 7 miles distant (lat. 30°58'30" N., long. 130°32'00" E.); 185-273
meters; bottom temperature 15.89° C.; rocky bottom; August 16, 1936 [A. H. Clark,
1907, 1908, 1912, 1915, 1918] (15, U.S.N.M., 22627, 35564, 35565, 35620, 36185).

Albatross station 4935; Eastern Sea, off Kagoshima Gulf; Sata Misaki Light
bearing N. 58° E., 4.5 miles distant (lat. 30° 57'20"N., long. 130°35'10" E.); 185
meters; bottom temperature 15.89° C.; bottom, stones; August 16, 1936 [A. H. Clark
1912, 1915, 1918] (1, U.S.N.M., 35566).

Albatross station 5070; Suruga Gulf; Ose Saki bearing S. 8° W., 1.8 miles distant
(lat. 35°03'25" N., long. 138°47'40" E.); 194 meters; bottom temperature 14.22° C.;
mud, sand, and broken shells; October 15, 1906 [A. H. Clark, 1912, 1915, 1918] (2,
U.S.N.M., 35624; M.C.Z., 344).

Albatross station 5069; Suruga Gulf; Ose Saki bearing S. 6.5° E., 1.7 miles distant
Gat. 35°03'10" N., long. 138°47'00" E.); 194-236 meters; bottom temperature from
13.22° to 17.22° C.; mud, sand, and broken shells; October 15, 1906 [A. H. Clark, 1912,
1915, 1918] (3, U.S.N.M., 35617).

Sagami Bay (lat. 35°03' N., long. 138°47' E.); 153 meters; Alan Owston, yacht
Golden Hind [A. H. Clark, 1908, 1912, 1915, 1918] (1, U.S.N.M., 35625 [original No.
7010]).

Albatross station 3719; off southern Japan; Ose Zaki bearing S. 13° W., 1.5 miles
distant; 128-166 meters; volcanic sand, shells, and rock; May 11, 1900 (1, M.C.Z.,
270).

Geographical range. — From the vicinity of Hong Kong northward to southern
Japan, from the Korean Straits to Sagami Bay.

Bathymetrical range. — From 128 to 306 meters; the average for all the records is
219 meters.

Thermal range.— From 10.78° to 15.89° C.; the average for all records is 13.67° C.

Character of bottom. — Rocky; stones; mud, sand, and broken shells; coral and
sand ; dark gray sand and broken shells; fine gray sand and broken shells; gray sand and
broken shells.

Note. — This is by far the most common and most generally distributed species of
the family Thalassometridae occurring in Japan, just as the corresponding species,
P. granulata, is the most common and most generally distributed species of the family
in the Philippine Islands.

History. — This species was first described under the name of Antedon orion in a
paper published on September 17, 1907. The type specimen had been dredged by the
Albatross at station 4934 in the previous year.

In my first revision of the old genus Antedon published on October 29, 1907, this
species was transferred to the new genus Charitometra and was listed as Charitometra
orion. In a paper on new genera of unstalked crinoids published on April 11, 1908, I
remarked that "the species compressa and orion, placed in Charitometra, should have
been referred to Thalassometra . . ." In another paper published on May 14, 1908,

82 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

I wrote that "In the lists of species belonging to the two genera published when I
established Thalassometra and Charitometra, orion and compressa were erroneously
assigned to the latter." In a revision of the families Thalassometridae and Himero-
metridae published on January 9, 1909, I established the new genus Parametra with
Antedon orion as the genotype. In a paper on the crinoids of the Zoological Museum
at Copenhagen published later in 1909 I recorded a specimen of Parametra orion from
near Nagasaki in 170 fathoms and gave notes regarding it. In a preliminary paper on
a collection of crinoids made by the United States Fisheries steamer Albatross in the
Philippine region published in 1911 I recorded three specimens, all bright yellow, from
between Fracas (=Pratas) reef and Formosa. The locality was Albatross station 5306
although this was not stated as no station number accompanied the specimens. I
wrote that "This species has the division series invariably smooth laterally and without
any median carination. It possesses rather fewer arms than P. compressa [=P. granu-
lata] and does not reach so large a size." In my memoir on the crinoids of the Indian
Ocean published in 1912 I listed Parametra orion, giving the range as southern Japan
and southward to Formosa (Taiwan) in 85-170 fathoms. In a paper on some crinoids
from eastern Asia collected by Captain Suensson while in command of one of the
Danish cable-repair steamers I recorded Parametra orion from south of the Goto Islands
hi 223 meters and gave notes on the specimen. In a paper on the distribution of the
comatulids of the coasts of China and Japan published in 1915 the bathymetrical and
thermal ranges of Parametra orion were given. In my report on the unstalked crinoids
of the Siboga expedition published in 1918 I inserted orion in a key to the species of
Parametra and gave the geographical and bathymetrical ranges and the synonymy.

Dr. Theodor Mortensen in a memoir on the development of crinoids published in
1920 stated that the eggs of Parametra orion are 0.15 mm. in diameter, only a little
smaller than the eggs of Tropiometra carinata, which are 0.2 mm. in diameter.

In 1922 Prof. Torsten Gislen described Perissometra aranea from a single specimen
collected by Dr. SLxten Bock at his station 7a near the Goto Islands and figured a distal
pinnule and a cirrus, both of which are typical of this species. He also mentioned
specimens in Dr. Mortenseu's collection. In his memoir on the Japanese crinoids
collected by Dr. Theodor Mortensen in 1914 he gave notes on three specimens of
Perissometra aranea from station 7, which is the same locality as Bock's station 7a,
and figured a P! from one of them. He also described Perissometra carinata from
two specimens from station 9, figuring the centrodorsal and cirri and the second-fifth
brachials with PI and P2, and giving a photograph of the type specimen twice enlarged.
In the same memoir Professor Gislen described Monachometra mortenseni from 12
specimens from station 9, and figured a cirrus and the lower part of an arm with P]
and P2.

It is, perhaps, only fair to Professor Gislen to say that the description of Perissometra
aranea, P. carinata, and Monachometra mortenseni, all based upon immature individuals
of Parametra orion should not be regarded as any reflection on him. The available
description of P. orion was poor and deficient in several important respects, and it had
not been figured. Superficially Parametra orion certainly resembles some species of
Charitometridae more closely than it does most of the species of Thalassometridae.
Everyone who has worked with the comatulids has made similar slips, and personally
I have been guilty of some much more serious ones.

A MONOGRAPH OF THE EXISTING CRINOIDS 83

PARAMETRA LISA. ap. DOT.

Diagnostic features. — -The arms beyond the proximal more or less oblong brachials
are distinctly carinate; and the cirri, which are arranged in 10 columns on the centro-
dorsal and are about one-quarter of the arm length with 25-26 segments, have the
transition segment the eighth, and the distal segments as long as broad with very small
and obscure dorsal processes. The 19 arms are 115 mm. long, and the cirri are 20-28
mm. long.

Description. — The centrodorsal is low, conical, with a low rounded conical dorsal
pole. The cirrus sockets are arranged in 10 columns of usually two each, there being
two columns in each radial area. The columns are in close contact interradially, but
are slightly separated in the mid-radial lines.

The cirri are XXI, 25-26, from 20 to 28 mm. in length, and rather slender. The
first segment is very short, the second is about twice as broad as long, the third is
slightly broader than long, the fourth is about one-third again as long as broad, and
those following gradually increase in length to the eighth, a transition segment, which
is between two and one-half and three times as long as its least width. The segments
following gradually decrease in length so that the last 15 or 16 are about as long as
broad. The basal portion of the cirri tapers slightly and slowly to the transition
segment. The sides of the transition segment converge very slightly to the beginning
of the distal third, then diverge to the end. Beyond the transition segment the cirri
remain of the same width to the tip. On the transition and following segments the
median portion of the distal border dorsally is roughened or armed with exceedingly
fine spines. On the succeeding segments it becomes slightly produced and also nar-
rowed, the profile of the outer portion of the cirri being slightly serrate dorsally. The
processes almost disappear on the antepenultimate segment. The penultimate seg-
ment is usually a truncated cone, with no trace of an opposing spine. The terminal
claw is about as long as the penultimate segment; it tapers gradually to a sharp point
and is only very moderately curved. The penultimate segment and the terminal
claw appear practically as a single unit. Often, however, there is a slight median or
subterminal tubercle representing the opposing spine on the penultimate segment, in
which case the terminal claw is usually shorter and more strongly curved. The long
peripheral cirri, none of which are fully developed, lack the transition segment, and
practically all traces of dorsal processes.

The radials are almost entirely, or even quite, concealed by the centrodorsal.
The IBrt are very short, longer laterally than in the median line, and in contact later-
ally. The IBr2 (axillaries) are in the median line three times as long as the IBri or
even longer. They are rhombic with truncated lateral angles, and are about half
again as broad as long. Their lateral edges converge slightly proximally and are not
in contact with those of their neighbors. In the proximal third they bear a fine median
elevated line which continues a similar median line on the IBi'i. The IIBr series and
IIIBr scries (when present) resemble the IBr series. The inner borders of the IIBri
and of the first brachials may be slightly everted.

The 19 arms are 115 mm. long. Five IIBr series are present, one on each post-
radial series. Four of the IIBr scries bear externally a IIIBr series. All the division
series are 2. A very narrow, low, inconspicuous, but always distinct, carinate line
runs along the middorsal line of the arms to their tips.

84 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

PI is 13 mm. long with 20 segments, moderately flexible, tapering gradually and
evenly from the base to the tip, which is not especially delicate. The first four segments
are about as long as broad and those succeeding are somewhat longer than broad, mostly
about half again as long as their proximal width. The first segment has the distal
border slightly convex. The second and third segments have the distal dorsal angle
extending somewhat beyond the base of the segments succeeding, and in the case of the
third somewhat produced. The fourth and following segments have both distal angles
extending slightly beyond the base of the segments succeeding, and in the last 8 or 9
segments the sides diverge slightly so that in this portion of the pinnule both the proxi-
mal and distal profiles are serrate. The outer surface of the pinnule is rather narrowly
rounded.

P2 is 7 mm. long with 12 segments; it is slightly less stout basally than P: and like
that pinnule tapers regularly to the tip. The first two segments are slightly broader
than long, the third is about as long as broad, and those following are longer than broad,
becoming half again as long as broad distally. The distal angles of the segments
extend slightly beyond the bases of the succeeding segments, this feature increasing in
amount distally, and are armed with exceedingly fine spines. The midline of the outer
surface of the pinnule is rather broadly roughened and is slightly elevated, forming a
roughened band which can scarcely be called a carination.

P3 is 5 mm. long with 9 segments; it resembles P2 and is basally of the same width.

P! resembles P3.

Notes. — The lateral separation of the axillaries and second brachials, the absence
of lateral flattening of the division series, and the very small and obscure dorsal processes
on the outer cirrus segments give this species superficially much more the appearance
of one of the Mariametridae than of a species of Thalassometridae.

Locality. — Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 32;
250 meters; sand; April 22, 1922 (1, C. M.).

PARAMETRA AJAX A. H. Clark

PLATE 9, FIGURE 29

Parametra ajax A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 635 (listed),
p. 649 (Malay Archipelago; description), pi. 41, figs. 6, 7.

Diagnostic features. — The arms are evenly rounded dorsally, as in P. fisheri, and
the brachials have the distal edge much thickened and produced and armed with very
numerous excessively fine teeth; and the cirri are relatively large and stout, XX, 23-27,
about one-quarter of the arm length.

Description. — The centrodorsal is thin discoidal with the very broad dorsal pole
rather deeply sunken and finely papillose. The cirrus sockets are arranged in one row
and a partial second irregular marginal row.

The cirri are XX, 23-27 (usually nearer the latter), from 20 to 25 mm. in length.
The first segment is short and those following gradually increase in length to the fifth
or sixth, which is almost or quite as long as broad. The sixth, seventh, or eighth is a
transition segment, and is about half again as long as broad. The outer third of the
segment is almost white, and the dorsal and ventral profiles of this white portion diverge
strongly, the dorsal making a greater angle with the longitudinal axis than the ventral.
The segments following decrease in length, after about four becoming about half again

A MONOGRAPH OF THE EXISTING CRINOIDS 85

as broad as long. The distal edge of the transition segment is rather strongly produced
dorsally. On the following segments this production of the distal dorsal edge takes the
form of a rather high transverse ridge with the crest flattened and dentate. Distally
this ridge gradually narrows and on the last six segments before the penultimate it is
transformed into a low submedian dorsal tubercle. The opposing spine is small, conical,
with the apex median or subterminal in position. The terminal claw is about as long
as the penultimate segment or slightly longer, rather slender, and gently and evenly
curved. The cirri increase slightly in width and thickness to the fourth or fifth segment,
then decrease to the end of the transition segment, after which point they remain
uniform.

The ends of the basal rays are visible as prominent and rather large rounded trian-
gular tubercles in the angles of the calyx.

The radials are wholly concealed. The IBrj are chevron shaped, very narrow, with
parallel sides, and are in close apposition. In the median line they bear a prominent
sharp keel or an elongate tubercle extending the entire length of the dorsal surface.
The lateral portions of the distal border may be unmodified, or they maj7 be extended
distally over the proximal portion of the axillaries in the form of a thin broadly scalloped
flange. The IBr2 (axillaries) are broadly rhombic, twice as broad as long; the lateral
angles are only very slightly truncated. The dorsal surface may rise to a broad rounded
prominence in the center with its maximum height in the proximal half, or the proximal
third of the median line may be occupied by a broad longitudinally elongate tubercle
or a sharp median keel. The IIBr series are 2, resembling the IBr series, rather narrowly
convex hi the median line, but without central tubercles or keels.

The 20 arms were probably about 90 mm. long. They are very narrow at the base,
increasing in width to about the fourteenth brachial and thence gradually tapering
distally. The first brachial varies from three times as broad as long in the median line
to only half again as broad as long. In the latter case it is wedge-shaped, longer ex-
teriorly than interiorly; in the former the proximal and distal borders are parallel as far
as the middorsal line, where the distal border turns anteriorly and runs diagonally
outward to the outer distal angle. When very short the first brachials have a prominent
elongate tubercle occupying the entire length of the median line, but usually the dorsal
surface is evenly convex and swollen so that the profile is strongly convex. The inner
distal angles are more or less cut away, as are the inner proximal angles of the second
brachials, so that conspicuous rhombic water pores are formed. The second brachials
are from two to three tunes as broad as long, in shape approximately oblong. Their
distal edges are slightly prominent. The first syzygial pair (composed of brachials 3 + 4)
is very slightly longer exteriorly than interiorly, usually about half again as broad as
long. The hypozygal (third brachial) is oblong, with the distal border raised above the
articular line; the epizygal (fourth brachial) is wedge-shaped, longer exteriorly than
interiorly, with the distal border prominent. The following eight brachials are wedge-
shaped, from three to four tunes as broad as long in the median line, with the longer
side about half again as long as the shorter. Their distal edges are usually raised
considerably above the bases of the brachials following, giving the profile of this portion
of the arm a serrate appearance; they are also usually somewhat thickened and very
finely dentate. The succeeding brachials become triangular, slightly broader than long,

86 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

with the distal border rather strongly concave and the distal edge strongly thickened
and produced and armed with very numerous excessively fine teeth.

P! is 7 mm. long and is composed of 1 7 segments. It is moderately stout at the base,
but tapers rather rapidly in the first nine segments and becomes slender from that point
onward. The first two segments are about twice as broad as long and those following
gradually increase in length, becoming about as long as broad on the fifth and sixth,
and somewhat more than twice as long as broad distally. The segments are sharply
carinate.

P2 is 9.5 mm. long with 18 segments. It is not quite so stout basally as P! and tapers
much more gradually. The segments are at first broader than long, becoming about as
long as broad on the fourth and twice as long as broad in the outer portion. The seg-
ments are sharply carinate, and in the distal half this carination is high and the distal
angle is distally produced, considerably overlapping the base of the segment succeeding.

P3 is 8.5 mm. long with 15 segments. It is about as broad basally as P2, but tapers
very gradually and evenly to the tip so that in its distal half it is twice as broad as
P2. The segments become as long as broad on the eighth and are distally about half
again as long as broad.

P4 is 9 mm. long with 16 segments, resembling P3 but tapering still more gradually
and hence broader throughout with relatively shorter segments.

On some arms Pl may be twice as broad basally as P2, though becoming more slender
in the distal half, while on others there is very little difference between them. On the
other arms PI and P2 may be relatively small, the former very slightly stouter basally
than the latter, and P3 may be much longer and broader than either.

Locality. — Malay Archipelago; from a cable; cable repair ship Patrol, Eastern and
Associated Telegraph Co. [A. H. Clark, 1929] (1, B.M.).

PARAMETRA FISHERI (A. H. Clark)

PLATE 9, FIGURE 28
[See also vol. 1, pt. 1, fig. 365, p. 297; pt. 2, fig. 218, p. 164.]

Thalassometrafisheri A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214 (in key), p. 223 (descrip-
tion; Albatross station 4122).

Parametra fisheri A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 16 (listed); Crinoids of
the Indian Ocean, 1912, p. 213 (synonymy; locality); Unstalked crinoids of the Siboga-Exped., 1918,
p. 158 (in key; range; references); Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 649
(compared with P. ajax); Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (Albatross station 4122),
p. Ill (station data).

Diagnostic features. — -The arms are evenly rounded dorsally; PI is basally much
enlarged, tapering to a slender distal portion; and the cirri are rather long, about one-
quarter of the arm length, with the transition segment the fifth and the distal segments
about as long as broad wdth prominent dorsal spines. The 13 arms are 110 mm. long,
and the cirri are 20-25 mm. long with 19-26 segments.

Description. — The centrodorsal is low hemispherical with a rather large polar area
bare. The cirrus sockets are arranged in 2 irregular marginal rows and 2 irregular
columns in each radial area.

The cirri are XV, 19-26 (usually nearer the latter) from 20 mm. to 25 mm. in
length. The first 2 segments are short, the third is not quite so long as broad, the fourth

A MONOGRAPH OF THE EXISTING CRIN01DS 87

is rather longer than broad, and the fifth, a transition segment, is somewhat over twice
as long as broad with the distal third highly polished. The next segment is about half
again as long as broad and those following decrease in length, after 3 or 4 becoming
about as long as broad and so remaining to the penultimate. The transition segment
and all the segments following bear prominent and sharp dorsal spines. The opposing
spine is blunt, and very small or obsolete. The terminal claw is longer than the penulti-
mate segment, and is relatively little curved.

The disk is unplated. The brachial ambulacra have well-developed plates. The
pinnule ambulacra have well-developed side and covering plates. Sacculi are abundant,
large on the brachial ambulacra, and small on the pinnules.

The ends of the basal rays are visible as small tubercles in the intcrradial angles
of the calyx.

The radials are concealed by the centrodorsal. The IBri are short, about 4 times
as broad as long, smooth, with the dorsal surface somewhat convex and bearing a large
low rounded tubercle in the median line. It is slightly chevron-shaped. The IBr3
(axillaries) are rhombic or almost low triangular, about twice as broad as long, with the
dorsal surface moderately convex. The IIBr series are 2, resembling the IBr series.

There are 13 arms in the type which are 100 mm. long. The first 2 brachials are
slightly wedge-shaped with the longer side out. The first syzygial pair (composed of
brachials 3 + 4) is rather less than twice as broad as long, with the hypozygal about
twice as long as the epizygal. The following brachials are oblong or slightly wedge-
shaped, about twice as broad as long, after the twelfth becoming obliquely wedge-shaped
and about as long as broad. The arms are rounded dorsally and the distal ends of the
brachials are prominent, though there is no overlapping.

Syzygies occur between brachials 3 + 4, again from between brachials 13+14 to
brachials 16+17, and distally at intervals of from 3 to 5 (most commonly 4) muscular
articulations.

PI is 7 mm. long with 16 segments the first 3 of which are rather disproportionately
large, about as broad as long, with broad and spinous dorsal keels, the remainder being
smaller and more slender, and longer than broad. P2 is 6 mm. long, more slender than
PI and tapering evenly from the base, with the basal segments not differentiated from
the others. It is composed of 14 segments of which the first 2 are about as long as
broad and those following slowly become elongated. The segments are slightly carinate
and are broader at their distal than at their proximal ends so that the pinnule has a
notched outline. The following pinnules are similar, but decrease in length to P8 and
then gradually increase distally, reaching a length of 8.5 mm. The distal pinnules have
the first segment short, the second about as long as broad, and the remainder gradually
becoming elongated, though the length never exceeds twice the width. The distal ends
of the segments are somewhat overlapping.

Locality. — Albatross station 4122; Hawaiian Islands; Barber's Point Light (near
Honolulu) bearing N. 82° E., 2.2 miles distant; 351-<543 meters; coarse coral sand and
shells; July 26, 1902 [A. H. Clark, 1908, 1909, 1912, 1918, 1929, 1949] (1, U.S.N.M.,
22686).

History. — This species is as yet known only from the type specimen described under
the name of Thalassometra fisheri in 1908 and transferred to the genus Parametra
in 1909.

88 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Genus LISSOMETRA A. H. Clark

Anledon (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 145.
Thalassometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.
Parametra (part) A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 214.

Lissometra A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 147 (in key; range), p.
160. — GISL£N, Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.

Diagnosis. — A genus of Tkalassometridae in which there is no appreciable expansion
of the earlier segments of the genital pinnules; the middle and distal brachials are some-
what compressed laterally and have an ill-defined median keel, but the division series
and arm bases are rounded dorsally with a strong median crest; the IIBr series are 2;
and the cirri are about one-third of the arm length with 30-34 segments. In the only
known species the 13-15 arms are 65 mm. long, and the cirri are 20 mm. long.

Geographical range. — Known only from the Eastern Sea off Kagoshima Gulf,
southwestern Japan.

Bathymetrical range. — Known only from 188 meters.

History. — The single species in this genus was described under the name Antedon
alboflava in 1907. Later in the same year, upon the establishment of the genus Thalas-
sometra, it was transferred to it. In 1912 it was listed as a species of Parametra. In
my memoir on the unstalked crinoids of the Siboga expedition published in 1918
Lissometra alboflava was listed under the genus Lissometra without any explanation;
the characters of the new genus were given in a key to the genera of the subfamily
Thalassometrinae.

LISSOMETRA ALBOFLAVA (A. H. Clark)

PLATE 11, FIGURE 34
[See also vol. 1, pt. 1, figs. 199, 200, p. 239; pt. 2, fig. 216, p. 161.]

Antedon alboflava A. H. CLARK, Proc. TJ. S. Nat. Mus., vol. 33, 1907, p. 145 (description; Albatross

station 4936).
Thaiassometra alboflava A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);

Proc. U. S. Nat. Mus., vol. 34, 1908, p. 318 (Japan).
Parametra alboflava A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 214 (synonymy; locality);

Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and

its significance).
Lissometra alboflava A. H. CLARK, Unstalked crinoids of the <Si6oga-Exped., 1918, p. 160 (references).

Description. — The centrodorsal is roughly hemispherical or bluntly conical, about
as broad at the base as high. The cirrus sockets are arranged in 15 crowded columns,
1 or 2 in each column.

The cirri are X-XV, 30-34, 20 mm. long. Only the fifth, or fifth and sixth, seg-
ments are longer than broad. The sixth and following segments bear sharp dorsal
spines. The first 5 segments are dark in color with a dull surface and the remainder
are nearly white with a polished surface, the transition taking place on the distal end
of the fifth segment. The cirri are stout basally, but taper somewhat rapidly to the
distal end of the third segment after which point they remain slender.

The disk is scantily plated. The brachial ambulacra are nearly naked. The
covering plates on the pinnules are small. The sacculi are numerous.

The ends of the basal rays are just visible as minute tubercles in the interradial
angles of the calyx.

A MONOGRAPH OF THE EXISTING CRtNOIDS 89

The radials are visible as small paired tubercles in the interradial angles. The
i are very short, deeply incised by the axillaries, and strongly carinate. The IBra
(axillaries) are short, broad, over twice as broad as long, and strongly carinatc. The
IIBr series resemble the IBr series, but the 2 elements are relatively slightly longer.

The arms are 13 or 15 in number, 65 mm. long, with about 110 brachials of which
the first 8 or 9 are oblong and the following are triangular, not quite so long as broad,
becoming elongate distally. The brachials in the distal two-thirds of the arm overlap
more or less. The elements of the IBr and IIBr series and the first 9 or 10 brachials are
sharply flattened laterally and are in close lateral apposition. The middle and distal
brachials are somewhat compressed laterally and have an ill defined median keel.

PI is 6 mm. long, longer and stouter than the succeeding pinnules though not
markedly so, with 12 segments which are about as long as broad and are flattened
exteriorly. The following pinnules decrease gradually in length to Ps or P9 which is 3
mm. long with 7 short segments, then become gradually longer again, reaching distally
a length of 8 mm. with 17 or 18 rather short segments, of which the first is short and
broad and the second trapezoidal.

Locality .—Albatross station 4936; Eastern Sea, off Kagoshima Gulf; Sata Misaki
Light bearing N. 21° E., 5.7 miles distant (lat. 30°54'30" N., long. 130°37'30" E.);
188 meters; stones; August 16, 1906 [A. H. Clark, 1907, 1908, 1912, 1915, 1918] (2,
U.S.N.M., 22634 [type], 35594).

History. — This species was originally described under the name Antedon albqflava
from two specimens from Albatross station 4936 in 1907, the specimens having been
dredged in the year previous. Later in 1907 it was transferred to the new genus
Thalassometra, and it was included as Thalassometra albqflava in a list of the crinoids
of Japan published hi 1908. In my memoir on the crinoids of the Indian Ocean
published in 1912 this species was listed as Paramctra alboflaoa, and the synonymy
and range were given. The significance of the range was discussed in a paper published
in 1915. In my report upon the unstalkcd crinoids of the Siboga expedition published
in 1918 this species was listed as Lissomctra albqflava and the original reference was
cited.

Genus CROTALOMETRA A. H. Clark

Antedon (part) BELL, Marine investigations in South Africa, vol. 4, 1905, p. 141, and following authors.

Thalasxo metro, (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126.

Crotalomelra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 80 (name used in the de-
scription of C. ruslica); Proc. U. S. Nat. Mus., vol. 36, 1909, p. 403 (diagnosis; genotype C.
eupedata); vol. 40, 1911, p. 12 (occurs in deep water in the Atlantic, but never intrudes on the
territory of the Polar-Pacific species'), p. 13 (common to southeastern Africa and the Bay of
Bengal, but not found in the Arabian Sea); Crinoids of the Indian Ocean, 1912, p. 10 (absent
from Japan), p. 24 (range), p. 59 (in key), p. 209 (original reference; type); Internal. Rev. gesamt.
Hydrobiol. und Hydrogr., 1914, pp. 4 and following (occurs in both Atlantic and Pacific; range);
Die Crinoiden der Antarktis, 1915, p. 164 (range), p. 181 (both Atlantic and Pacific; range in
each); Unstalked crinoids of the Sibo^a-Exped., 1918, p. 148 (in key; range; key to the included
species); Univ. Iowa Studies in Nat. Hist., vol. 9, No. 5, 1921, p. 13 (West Indies and Indo-
Pacific), p. 19 (in key); The Danish Inyolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range). —
GISLEN, Vid. Medd. Dansk Naturh Foren. K0benhavn, vol. 83, 1927, p. 6. — MORTENSEN, Hand-
book of the cchinoderms of the British Isles, 1927, p. 25 (Atlantic species; in key). — A. H. CI.*RK,
Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 654. — GISL£N, Kungl. Fysiograf. Sallsk.
Handl., new ser., vol. 45, No. 11, 1934, p. 22; Kucgl. Svcnska Vet.-Akad. Handl., ser. 3, vol. 17,
No. 2, Oct. 3, 1938, p. 5.

843803— BO 7

90 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Diagnosis. — A genus of Thalassometridae in which the arms are dorsally rounded
to the tip; the arms in fully developed individuals are more than 15 (normally 20) in
number, with the IIBr series 4(3+4), exceptionally 2; the division series are smooth
and without spines though the lateral edges of the ossicles may be everted and tuber-
cular or serrate; the first syzygy following a IIBr 4(3+4) series is between brachials
3+4; the cirri are recurved distally, the outer segments carinate or with dorsal spines;
and the genital pinnules are not appreciably expanded. All the included species are
large, full sized individuals having the arms 110-160 mm. long.

Geographical range. — From Formosa (Taiwan) and the Philippine Islands south-
ward to the Moluccas and westward to the Maldive and Laccadive Islands and south-
eastern Africa from Durban to Port Elizabeth.

Baihymetrical range. — From 55 to 2,047 meters.

Remarks. — When fully developed the species of Crotalometra are quite distinctive
and are not easily confused with the species of any other genus, the large size, 20 or
about 20 arms with the IIBr series 4(3 + 4), and the long and stout cirri giving them
a characteristic appearance. Much depends, however, on the condition of the pre-
served specimen. If the arms are extended parallel with each other so that the division
series are fully visible and in contact a specimen of any of the species is unmistakable.
If, however, the arms are recurved over the centrodorsal the appearance changes
completely so that in most cases an analysis of the characters becomes necessary.

Three species of Crotalometra are recognized herein — sentifera, rustica, and magni-
cirra. As synonyms under rustica are included infelix, marginalis, and eridanella, the
type specimens of which do not seem to differ from rustica to any significant degree.

The only reliable feature for specific differentiation in the genus Crotalometra
appears to be the relative production of the distal dorsal edge of the outer brachials.

History. — The first known species of Crotalometra was described under the name of
Antedon magnicirra by Prof. F. Jeffrey Bell in 1905. At the time I published my first
revision of the genus Antedon in 1907 I had not been able to consult the description of
Antedon magnicirra, but in a paper published on April 11, 1908, 1 referred it to the genus
Thalassometra. The generic name Crotalometra was first used in a paper published on
April 17, 1909, in the combination Crotalometra rustica, sp. nov., under which heading
this species was described. The genus Crotalometra therefore dates from this appearance
of the name, with C. rustica as the genotype. In a paper on new Philippine crinoids
published on May 13, 1909, but submitted for publication in advance of the paper just
cited, the new genus Crotalometra is diagnosed, and the genotype is given as C. eupedata,
new species, the description of which follows. Under Crotalometra I said:

Carpenter's Anledon valida, the systematic position of which has puzzled me greatly, belongs to
this genus, and is closely related to C. eupedata, though apparently perfectly distinct; Anledon incerla
also should be referred to this genus. The Antedon magnicirra described from South Africa by Professor
Bell is likewise a member of this genus, and I have examined two or three additional species from the
East Indian region.

In a paper on the Recent crinoids of the coasts of Africa published on March 15,
1911, I listed and gave the ranges of Crotalometra magnicirra, C. porrecta, and C.flava
(the last two herein referred to the new genus Koehhrmetra) . In my memoir on the
crinoids of the Indian Ocean published in 1912 I gave the range of Crotalometra as from
the Kermadec and Meangis Islands to the Philippines in 340-630 fathoms, and listed

A MONOGRAPH OF THE EXISTING CRINOIDS 91

under the genus, with the synonymy and ranges, C. eupedata, C. propinqua, C. valida,
and C. incerta, accepting Crotalometra in the sense of its formal description instead of
its first appearance. Under Thalassometra were listed Th. magnicirra, Th. rustica, Th.
sentifera, and Th. infelix, herein referred to Crotalometra. In a paper on the crinoids of
the British Museum published in 1913 there appears the heading "Genus Aglaometra
A. H. Clark" under which are given notes on Aglaometra valida and A. incerta.

The genus Aglaometra is inserted in a key to the genera of the subfamily Thalasso-
metrinae in my memoir on the unstalked crinoids of the Siboga expedition, and a key to
the included species (vera, propinqua, sulcata, eupedata, valida, and incerta) is given.
These 10-armed forms are therefore definitely removed from the genus Crotalometra,
which in the Siboga report is given as including C.flava, C. porrecta, C. sentifera, C. rus-
tica, C. marginalia, and C. magnicirra. Since the publication of the Siboga report the
status of the genus Crotalometra has remained unchanged. In the present work the
two Atlantic species, porrecta and flam, which differ markedly from the Indo-Pacific
forms, are set apart as constituting the new genus Koehlermetra.

KEY TO THE SPECIES IN THE GENUS CROTALOMETRA

o'. Brachials beyond the proximal third of the arms with the central portion of the distal dorsal edge
produced into long overlapping spines which are more or less flattened dorsoventrally and
rounded or truncate at the tip; 12-19 arms 150-160 mm. long; cirri 40-50 mm. long with 51-62

segments (Maldive and Laccadive Islands; 914-1,265 meters) sentifera (p. 91)

aj. Brachials beyond the proximal third of the arms not produced into long overlapping dorsal spines.

6'. Brachials beyond the proximal third of the arms strongly overlapping, the central portion of the

distal dorsal edge somewhat produced and spinous; 13-20 arms 90-150 mm. long; cirri 55-85

mm. long with 45-70 segments (Moluccas and the Malay Archipelago to Formosa and Madras;

55-2,047 meters) rustica (p. 91)

ft2. Brachials beyond the proximal third of the arms with the distal borders unmodified, or at least
not conspicuously modified; 16-20 (usually 20) arms 75-110 + mm. long; cirri 55-70 mm. long
with 50-63 segments (southeastern Africa from Durban to Port Elizabeth; 91-731 [?823J
meters) magnicirra (p. 97)

CROTALOMETRA SENTIFERA A. H. Clmrk

PLATE 32, FIGURES 100-103

Crotalomelra senlifera A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 147 (description;
lat. 10°47'45" N., long. 72°40'20" E., 703 fms.); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 551
(compared with C. infelix); Unstalked crinoids of the Sifcoga-Exped., 1918, p. 149 (in key; range;
references); Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 654 (compared with C.
eridanella, sp. nov. [ = C. rustica]); John Murray Exped. 1933-34, Sci. reports, vol. 4, No. 4, 1936
(January 1937), p. 87 (listed), p. 92 (Mabahiss station 158; notes; range), pp. 98, 101, 103.

Thalassometra sentifera A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 201 (synonymy; descrip-
tion; locality), fig. 37, p. 202.

Diagnostic features. — The brachials of the middle and outer portions of the arms
have the central portion of the distal edge produced into long and conspicuous more or
less dorsoventrally flattened overlapping spines. The 12-19 arms are 150-160 mm.
long, and the cirri are 40-50 mm. long with 51-62 segments.

Description. — The cirri are XX, 59-62, 50 mm. long.

The 12-16 arms are from 150-160 mm. long. After the proximal third of the arm
the brachials bear long overlapping spines which are more or less flattened dorsoventrally
and rounded or truncated at the tip.

92 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In characters other than those mentioned this species resembles C. magnicirra and
C. rustica.

Notes. — One of the specimens from Mabahiss station 158 has 18 or 19 arms. The
cirri are about 40 mm. long with 51-55 segments; the eighth is a transition segment.
On the centrodorsal the pairs of columns of cirrus sockets are separated in the mid-
radial line by a broad and rather deeply concave bare area. The proximal edge of
the IBri, the proximal and distal edges of the IBr2, and the proximal edge of the IIBr!
are everted and armed with a few short coarse spines.

The second specimen is similar, with 15+ arms. The longest cirri are 47 mm.
long, with 61-63 segments. The transition segment is the eighth. The pairs of cirrus
sockets are separated by a broad midraclial space. The dorsal pole of the centrodorsal
is papillose.

Localities. — Investigator station 124; Laccadive Islands (lat. 10°47'45" N., long.
72°40'20" E.); 1,265 meters; large water-worn fragments of reef coral [A. H. Clark.
1909, 1911, 1912, 1918, 1937] (2, U.S.N.M., 35582; I. M.).

Mabahiss station 158; Maldive Islands (lat. 4° 42'30" to 4°36'48" N., long.
72°42'30" to 72°48'54" E.); 914 meters; April 7 1934 [A. H. Clark, 1937] (2, B. M.;
Cairo Mus.).

Geographical range. — From the Maldive to the Laccadive Islands.

Bafhyinetrical range. — From 914 to 1,265 meters.

History. — This species was first described in 1909 under the name Crotalometra
sentifera from two specimens collected by the Royal Indian Marine Survey Steamer
Investigator at station 124 in the Laccadive Islands. In 1911 Crotalometra sentifera
was compared with the new species C. infelix. In 1912 this species was redescribed
and figured under the name of Thalassometra sentifera. In my memoir on the un-
stalked crinoids of the Siboga expedition published in 1918 sentifera was included in
the key to the species of Crotalometra, and the synonymy and range were given. In 1937
two additional specimens of Crotalometra sentifera were recorded and described that
had been dredged at station 158 in the Maldive area by His Egyptian Majesty's steamer
Mabahiss operating under the auspices of the John Murray Expedition to the Indian
Ocean, 1933-34.

CROTALOMETRA RUSTICA A. H. Clark

PLATE 11, FIGURES 35, 36; PLATE 18, FIGURE 58
[See also vol. 1, pt. 2, fig. 283, p. 215.]

Crotalometra rustica A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 80 (description;

Malay Archipelago, 30 fathoms), p. 147 (related to C. sentifera); Unstalked crinoids of the Siboga-

Exped., 1918, p. 149 (in key; range; references); Ann. Mag. Nat. Hist., ser. 10, vol. 10,

No. 58, October 1932, p. 378 (listed), p. 383 (off Madras; 600 fathoms; notes), pi. 15.
Crotalomelra infelix A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 550 (description; Albatross

station 5317); Unstalked crinoids of the Si&o^a-Exped., 1918, p. 149 (identity).
Thalassometra rustica A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, pp. 424, 425 (compared with

marginalis) ; Crinoids of the Indian Ocean, 1912, p. 198 (synonymy; detailed description; locality),

fig. 36, p. 199.
Thnlassomelra marginalis A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 424 (description;

Siboga station 226) .
Thalassometra infelix A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 203 (synonymy; locality).

A MONOGRAPH OF THE EXISTING CRINOIDS 93

Crotalometra marginalia A. H. CLARK, Unstalked crinoids of the Si&oja-Exped., 1918, p. 149 (in key;

range), p. 150 (detailed description; station 226), p. 274 (listed), pi. 23, fig. 62. — Gisi/fiN, Ark.

Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8 (probably a large specimen of C. magnicirra).
Crotalomelra eridanella A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 635

(listed), p. 654 (off Great Nicobar, 1,040-1,120 fathoms; description), pi. 42, fig. 9.
Crotalometra marginata GIBL^N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 23.

Diagnostic features. — The brachials of the middle and outer portions of the arms
have the central portion of the distal edge somewhat produced and spinous. The
13-20 arms are 90-150 mm. long, and the cirri are 55-85 mm. long with 45-70 segments.

Description. — The centrodorsal is apparently as in C. magnicirra, with the cirrus
sockets arranged in 10 columns, two in each radial area.

The cirri are XX, about 70 (69 to broken tip), 85 mm. long, large and stout. The
first three segments are subequal, about three times as broad as long, the fourth is
slightly longer, the fifth is about as long as broad or slightly longer than broad, and those
following are about one-third again as long as broad, becoming as long as broad after
the eighteenth and after four or five more about twice as broad as long. The eighteenth
is a transition segment. Following the transition segment the dorsal surface of each
segment gradually rises into a subterminal dorsal tubercle which, however, never
projects in the form of a spine. The tubercle is at first rather broad transversely and
rounded dorsally, but distally it becomes narrower so that the dorsal surface of the
segment becomes bluntly carinate. Viewed laterally the dorsal profile of the cirri
presents a slightly serrate appearance.

The ends of the basal rays are visible as prominent dorsoventrally elongated
tubercles in the iuterradial angles of the calyx.

The radials project very slightly beyond the rim of the centrodorsal. The IBri
are very short and bandlike, about five times as broad as long, with the proximal
border convex and the distal concave, and are in close lateral apposition. The IBr2
(axillaries) are broadly pentagonal, half again as broad as long, with all the sides
strongly concave. The lateral borders of the two components of the IBr series taken
together are evenly and strongly concave, the proximal width of the IBri and the distal
width of the IBr2 being about the same. Both these ossicles are sharply flattened
laterally with the apposed edges somewhat everted. The IIBr series are 4(3 + 4), very
strongly rounded dorsally like the IBr series, in close lateral apposition and sharply
flattened against their neighbors. The lateral edges are somewhat produced. The
elements of this division series are relatively rather long.

The 20 arms are about 150 mm. long, deep and laterally compressed, and strongly
rounded dorsally. The first brachials are very short and strongly concave distally.
The second brachials are much larger with a posterior process incising the first. The
first syzygial pair (composed of brachials 3 + 4) is about as long as broad with the dorsal
and lateral profiles concave as in the syzygial pair formed by the two distal elements of
the I IBr series. The following brachials to the ninth are wedge-shaped, half again as
broad as long. The brachials following are triangular, about as long as broad, in the
terminal portion of the arm becoming wedge-shaped again and slight!}7 longer. After
the proximal third of the arm the brachials develop prominent and spinous distal ends
and a striated dorsal surface.

Syzygies occur between brachials 3 + 4, again from between brachials 15 + 16 to
between brachials 19 + 20, and distally at intervals of from 4 to 9 muscular articulations.

94 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

PD is 15 mm. long, large and stout in the basal half but tapering to a slender tip,
composed of about 25 segments of which the second-seventh are broader than long
and the remainder are about as long as broad. PI is 12 mm. long with 23 segments,
much less stout than PD, with the distal segments somewhat spinous along the dorsal
ridge. PS is 7 mm. long, considerably more slender than P2, tapering evenly from the
base to the end of the proximal half, slender in the distal half, composed of 16 segments
all but the first two of which are about as long as broad. The following pinnules are of
about the same length but scarcely taper at all until near the tip and hence appear
somewhat stouter; they are composed of about 14 segments. The distal pinnules are
moderately slender, 12 mm. long with 20 segments of which the first is trapezoidal,
about twice as broad distally as the median length, the second is trapezoidal, somewhat
broader distally than the median length, and the remainder are slightly longer than
broad; the dorsal ridge is very sharp and more or less spinous.

The color in alcohol is white.

Notes. — The preceding description is based upon the type specimen in the Indian
Museum at Calcutta from the Malay Archipelago in 30 fathoms.

The specimen from Albatross station 5317 was described as a new species,
Crotalometra infelix, in the following terms. The centrodorsal is low-conical with the
apex abruptly prolonged. The cirrus sockets are arranged in 10 closely crowded
columns.

The cirri are XX, 38-44, from 25 to 30 mm. long. The first segment is short and
those following gradually increase in length becoming about as long as broad on the
fifth and half again as long as broad on the seventh. The segments following gradually
decrease in length becoming about as long as broad on the eleventh and from half again
to twice as broad as long distally. The eighth and following segments have produced
distal dorsal edges which soon become prominent dorsal spines.

The ends of the basal rays are visible in the interradial angles of the calyx as
dorsoventrally elongate tubercles.

The radials are short, about four times as broad as long, with a prominent median
tubercle. The IBr] are broader proximally than distally, and about twice as broad
distally as long in the mid-dorsal line ; they bear a low broadly rounded median carina-
tion which is most prominent posteriorly. The IBr2 (axillaries) are rhombic, half
again as broad as long; the proximal two-thirds of the median dorsal line is raised into
a low broad tubercle. The IIBr series are 4(3+4).

The 13 arms are 90 mm. long. After the proximal third the brachials gradually
develop produced and overlapping spinous distal edges, at the same tune becoming
laterally compressed. After the proximal half this production of the distal edge becomes
very prominent, especially in the median line.

I said that this species is nearest to C. sentijera, but the centrodorsal is propor-
tionately much smaller and bears closely crowded columns of cirrus sockets without
bare midradial areas, the edges of the elements of the IBr series are smooth instead of
finely dentate, the IB^ has a distinct, though low, rounded median carination, and the
distal overlap of the brachials, though very prominent, is not produced into the long
overlapping spine characteristic of C. sentijera. I added that the type of C. infelix is
a small specimen and that larger specimens may prove to approach C. sentijera, "though
it seems most probable that the two forms are quite distinct."

A MONOGRAPH OF THE EXISTING CRINOIDS 95

The specimen from off Madras has 17 arms 120 mm. long, 7 IIBr 4(3+4) series
being present. One of the postradial series is in process of adolescent autotomy. The
cirri have 62-68 segments and are up to 63 mm. in length. I noted that this specimen
seems without any doubt to be a young example of C. rustica.

Two specimens from Siboga station 226 were described as a new species under the
name of Thalassometra marginalis. Their characters were as follows:

The centrodorsal is low, rounded conical. The cirrus sockets are arranged in 10
columns of 2 each, the two columns of each radial area being in close contact with those
of adjacent radial areas but separated interiorly by a bare triangle basally about half
as wide as a cirrus socket that comes to a point just beyond the last functional socket
and is continued thence as a narrow line to the dorsal pole.

The cirri have 60 segments and are 50 mm. long.

The ends of the basal rays are veiy prominent as high dorsoventrally elongate
tubercles which are usually rather longer than the dorsoventral length of a cirrus socket.

In one specimen a small portion of the lateral end of the radials is visible as two
elongate tubercles meeting in a triangle over the ends of the basal rays. The proximal
borders of the IBri are produced into a narrow rim that projects downward over the
radials almost or quite concealing them, but cut away in the interradial angles to
accommodate the ends of the basal rays.

One of the specimens has 17 arms about 95 mm. long; two of the IIBr series are
2 and five are 4(3 + 4). The other, of the same size, has 18 arms with all eight IIBr
series 4(3 + 4).

I wrote that the two individuals of Thalassometra marginalis have about half the
arm and cirrus length of Crotalometra rustica, though apparently they represent a
species very closely related to it, and also to C. magnicirra. The new species was sup-
posed to differ from C. rustica in having the proximal edge of the IBri produced down-
ward into a narrow rim that projects over the radials entirely, or almost entirely, con-
cealing them. In the interradial angles the IBri are cut away to accommodate the basal
rays, whereas in C. rustica they are separated from the basal rays by the radials, which
form a continuous band all around the calyx. These differences are scarcely of specific
importance.

A specimen from off Great Nicobar in 1,040-1,120 fathoms was described as a new
species under the name of Crotalometra eridanella as follows:

The centrodorsal is hemispherical. The cirrus sockets are arranged in 10 columns,
usually three to a column. There are two columns in each radial area, one along each
side, each of these closely crowded against the adjacent column in the adjoining radial
area. The central portion of each radial area is occupied by a bare sunken strip which
is somewhat less in width that the breadth of the adjacent cirrus sockets.

The cirri are about XXV, 45-57, large and stout, probably from 55 to 60 mm. in
length. The first segment is very short and those following increase in length to the
sixth, which is about as long as broad, or slightly longer than broad, and increase still
further to the tenth, a transition segment, which is about half again as long as broad.
From the eleventh onward the segments gradually decrease in length so that those in
the terminal third of the cirri are about twice as broad as long. On the tenth the dorsal
portion of the distal edge is slightly produced, and as the segments become shorter this
production of the distal edge extends proximally and at the same time rises so that the

96 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

short distal segments have a high dorsal carination with the rather abruptly rounded
apex subterminal in lateral view. In lateral view the cirri are stout basally, tapering
noticeably in the first six or eight segments, increasing slightly in width beyond the tenth,
and in the distal fourth tapering to a small tip.

The radials and part of the IBri are concealed by the centrodorsal which in the
interradial angles is extended anteriorly so as almost or quite to meet the lateral angles
of the axillaries. The IBri are short and crescentic, incised in the median line by the
backward extension of the axillaries and with the lateral borders reduced to a point.
The IBr2 (axillaries) are broad, rhombic, twice as broad as long, with the lateral angles
truncated and the short sides thus formed flattened against those of the adjacent ossicle.
Of the four IIBr series present two are 4(3 + 4) and two are 2. They are well rounded
dorsally, but are in lateral contact. The borders and dorsal surface of the elements of
the division series are entirely smooth, and there is only a very slight elevation at the
synarthries.

The 14 arms were probably about 140 mm. long. The earlier brachials are broadly
and evenly rounded dorsally and entirely smooth, with only a very slight eversion of the
ends which is very minutely, if at all, spinous. The position of the articular tubercles is
faintly indicated. After the brachials become triangular the production of the distal
border becomes more marked and more prominently spinous, and on the brachials in
the outer half of the arm there is a strong spinous overlap and the central portion of the
distal edge of the brachials may bear an abrupt tuft or fin of rather long spines.

P! is 12 mm. long with 20 segments; it is fairly stout at the base and tapers evenly
to a slender tip. The segments become about as long as broad on the fifth, and twice
as long as broad on the thirteenth. The small elongated distal segments have spinous
ends.

Ps is 7 mm. long with 15 segments, proportionately smaller than PI. The segments
become as long as broad on the third or fourth, and twice as long as broad on the tenth.

P3 is shorter and less stout basally than P2.

The distal pinnules are 12 mm. long with 20 or 21 segments, of which the first is
short, the second is half again as broad as long, the third is about as long as broad, and
the outer are twice as long as broad. The dorsal keel on the segments is sharp and rather
coarsely spinous, and there is a little tuft of spines at the end of each segment.

In diagnosing this supposed new species I said that it is a species of Crotalometra in
which the cirri, which are large and stout and composed of 45-57 segments, are arranged
in 10 columns on the centrodorsal; the brachials beyond the proximal third of the arms
have the distal edges strongly overlapping, the central portion of the distal edge often
bearing an abrupt tuft or fin of rather long spines (more or less as in C. sentifera) .

Localities. — Siboga station 226; Moluccas; mid channel between the Lucipara and
Schildpad Islands (lat. 5°26'42" S., long. 127°36'30" E.); 1,595 meters; hard bottom,
only small stones in the dredge; November 11 and 12, 1899 [A. H. Clark, 1912, 1918;
Gislen, 1928, 1934] (2, Amsterdam Mus.).

Investigator; Malay Archipelago; 55 meters [A. H. Clark, 1909, 1912, 1918] (1,
I. M.).

Albatross station 5317 (listed in the dredging records as 5517); China Sea in the
vicinity of Formosa (Taiwan) (lat. 21°36'00" N., long. 117°27'00" E.); 420 meters;

A MONOGRAPH OF THE EXISTING CRINOIDS 97

sand and small shells; November 5, 1908 [A. H. Clark, 1911, 1912, 1918] (1, U.S.N.M.,
27499).

Off Great Nicobar Island Gat. 6°15' N., long. 93°35' E.); 1,901-2,047 meters;
cable repair ship Patrol, Eastern and Associated Telegraph Co. [A. H. Clark, 1929] (1,
B. M.).

Off Madras (lat. 12°53' N., long. 80°45' E.); 1,097 meters; cable repair ship The
Cable, Eastern Australasia and China Telegraph Co., through A. A. Davison [A. H.
Clark, 1932] (1, B. M.).

Geographical range. — From the Moluccas and the Malay Archipelago northward
to Formosa (Taiwan) and northwestward to Madras.

Bathymetrical range. — From 55 to 2,047 meters.

History. — This species was first described in 1909 under the name of Crotalometra
rustica from a single badly broken specimen that had been dredged by the Royal
Indian Marine Survey steamer Investigator in the Malay Archipelago in 30 fathoms.
In 1911 I described under the name of Crotalometra infelix a small individual that un-
doubtedly belongs to the same specific type. In 1912 I described Thalassometra mar-
ginalis from two specimens from Siboga station 226, and in my memoir on the crinoids
of the Indian Ocean published toward the end of the year I redescribed and figured
Thalassometra rustica and listed Th. infelix with the synonymy and range. In my
memoir on the unstalked crinoids of the Siboga expedition published in 1918 I listed
Crotalometra rustica, under which I placed Crotalometra infelix as a synonym, and re-
described and figured Crotalometra marginalia.

When giving some notes on Crotalometra magnicirra in 1928 Prof. Torsten Gislen
said that C. marginalis is probably a large specimen of this species.

In 1929 I described and figured Crotalometra eridanella from a specimen from off
Great Nicobar Island that had been brought up on a cable from a depth of 1,040-1,120
fathoms by the cable repair ship Patrol of the Eastern and Associated Telegraph
Company. In 1932 I recorded and figured C. rustica from a specimen from off Madras in
600 fathoms that had been found on a cable brought to the surface by the cable repair
ship The Cable of the Eastern Australasia and China Telegraph Co. and had been
sent to the British Museum by A. A. Davison.

Professor Gisleii discussed certain features of the structure of Crotalometra mar-
ginata in 1934.

CROTALOMETRA MAGNICIRRA (Bell)

Anledon magnicirra BELL, Marine investigations in South Africa, vol. 4, 1905, p. 141 (description;
localities), pi. 4, figs. 1-3. — A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126
(belongs to the genus Thalassomelra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 482 (systematic
position); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (not placed in a revision of the
Thalassometridae) ; Proc. U. S. Nat. Mus., vol. 36, 1909, p. 404 (referred to Crolalometra) ; vol.
40, 1911, p. 5 (= Crotalometra magnicirra); Crinoids of the Indian Ocean, 1912, p. 41 (identity);
Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 84 (B. M., MS. = sdaleri).

Anledon magnicirrus BELL, Marine investigations in South Africa, vol. 4, 1905, p. 142 (editorial error).

Anledon magnicrinus BELL, Marine investigations in South Africa, vol. 4, 1905, pi. 4 (editorial error).

Thalassomelra magnicirra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126; Proc.
U. S. Nat. Mus., vol. 34, 1908, p. 482; Amer. Nat., vol. 42, No. 500, 1908, p. 542 (characteristic
oceanic species); Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same); Zool. Anz., vol. 39, No.
11/12, 1912, p. 424 (compared with Th. [Crolalomctra] marginalis); Crinoids of the Indian Ocean
1912, p. 41 (identity), p. 198 (synonymy; locality).

843803 — 5

98 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Crotalometra magnicirra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 80 (compared
with C. rustica); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 147 (related to C. sentifera);
Proc. U. S. Nat. Mus., vol. 40, 1911, p. 5 (identity), p. 8 (locality), p. 36 (synonymy; localities
in detail); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 45 (published references to specimens
in the B. M.; stations 12792 and 12885/6; characters of the cirri and centrodorsal) ; Die Crinoiden
der Antarktis, 1915, p. 164 (represents the family Thalassometridae in South Africa; range);
Unstalked crinoids of the Siboga-Exped., 1918, p. 149 (in key; range), p. 150 (synonymy). —
H. L. CLARK, Ann. South African Mus., vol. 13, pt. 7, No. 12, 1923, p. 234 (synonymy: locality). —
GiSLfiN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8 (C. marginalis probably a large specimen
of this species). — A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936
(January 1937), p. 101 (range), p. 105. — GISL£N, Kungl. Svenska Vet.-Akad. Handl., ser. 3,
vol. 17, No. 2, Oct. 3, 1938, pp. 4, 17 (localities; notes).

Diagnostic features. — The brachials of the middle and outer portions of the arms
have the distal edges unmodified, or at least not conspicuously modified. The 16-20
(usually 20) arms are 75-110+ mm. long, and the cirri are 55-70 mm. long with 50-63
segments.

Description. — On the centrodorsal the cirrus sockets are arranged in 10 columns,
with the two columns in each radial area separated from each other by a midradial
furrow.

The cirri are XV-XXV, 50-63, from 55 to 70 mm. long; the eighth or ninth is a
transition segment.

The IIBr series are 4(3+4), exceptionally 2. The margins of the elements of
the IBr series may be smooth or everted and finely denticulate; these ossicles may
have an indistinct longitudinal carination.

The 16-20 (usually 20) arms are from 75 to 110+ mm. long.

Notes. — This species has never been adequately described, and no specimens are
available for redescription. The description given above was compiled from scattered
notes, chiefly by Professor Gisleii.

Bell's original description was as follows:

This species appears to stand next to A. [Adelometra] angustriadia of Carpenter's classification,
for there are three distichals [IIBr series] not succeeded by palmars [IIIBr series], and the cirri are of
great length, but not in as many as ten vertical rows, nor is the distichal pinnule [Pn] larger than the
rest.

The centrodorsal is high, with three or four vertical rows of sockets, the cirri may be as much
as 70 mm. long, and the joints 60-80 in number; the most proximal one very short, the next much
longer, their successors broad and flattened from side to side, the distal 40 are keeled. The proximal
arm joints are fairly rectangular, the rest are narrower, alternately, on one side than the other; no
pinnules are very long, but they are all stout.

Length of arm about 100 mm. Colour, cream yellow.

In the British Museum I examined 6 specimens under Nos. 12885/6 and 1 under
No. 12792. The cirri are XV-XXV, 60-63; the eighth or ninth is a transition seg-
ment. The cirrus sockets are arranged in 10 columns, the two columns in each radial
area being separated from each other by a midradial furrow.

A specimen from 20 miles NW. 1/2 N. of East London, according to Gislen, is
small; the centrodorsal is dorsally spinous; there are 39 cirrus segments; the elements
of the IBr series have an indistinct longitudinal crest but are otherwise smooth; the
10 arms are about 75 mm. long. Another specimen from the same locality is larger;
there are 50 cirrus segments; the margins of the elements of the IBr series are everted,

A MONOGRAPH OF THE EXISTING CRINOIDS 99

the eversions being finely denticulate; there are 16 arms; following a IIBr axillary syzy-
gies occur between brachials 1 + 2 and 3+4.

In a specimen from 7.5 miles NW. by N. of the Umhlangakulu River the one cir-
rus remaining is 70 mm. long with 63 segments; the 20 arms are 80 mm. long.

In a specimen from Union of South Africa stations 3719-20 the cirri are about
55 mm. long with about 50 segments. In an example from Union of South Africa
station 4068 the cirrus sockets are arranged in 10 columns of the centrodorsal; the
cirri are 65 mm. long with about 60 segments; the 20 arms are 110+ mm. long.

In a specimen from Union of South Africa station 6244 four of the IIBr series are
2 and six are 4(3 + 4). In another specimen from the same station the IIBr series
are probably all 4(3+4).

Localities. — Pieter Faure; Buffalo River, East London, bearing N. 15 miles distant;
567 meters; coral and mud (12885/6) [Bell, 1905; A. H. Clark, 1908, 1909, 1911, 1912,
1913, 1915, 1918; H. L. Clark, 1923; GisleX 1928] (6, B. M.).

Pieter Faure; Buffalo River, East London, bearing N. W. }'i W. 19 miles distant;
548 meters; sand and broken shells (12725) [Bell, 1905; A. H. Clark, 1908, 1909, 1911,
1912, 1913, 1915, 1918; H. L. Clark, 1923; Gislen, 1928].

Pieter Faure; East London bearing N. W. % N., approximately 20 miles distant;
731-823 meters; sand and stones (12792 or 12792A) [Bell, 1905; A. H. Clark, 1908,
1909, 1911, 1912, 1913, 1915, 1918; H. L. Clark, 1923; Gislen, 1928] (1, B. M.).

Pieter Faure; 7.5 miles N. W. by N. of Umhlangakulu River, southern Natal; 91
meters; sand, gravel, and sponge fragments (12831) [Gislen, 1938].

Union of South Africa stations 3719-20; east of Durban (Port Natal), Natal (lat.
29°51' S., long. 31°28' E.) [Gisten, 1938].

Union of South Africa station 4068 [GislSn, 1938J.

Union of South Africa station 6244; northeast of Durban, Natal (lat. 29°34' S.,
long. 31°32' E.) [Gislen, 1938].

Geographical range. — Southeastern Africa from the vicinity of Port Elizabeth
northeastward along the coast to Durban (Port Natal), Natal.

Bathymetrical range. — From 91 to 731 (7823) meters; the average of four records
is 552 meters.

History. — This species was described as Antedon magnicirra in 1905 by Prof.
Francis Jeffrey Bell from an unspecified number of specimens dredged off East London
in 300-450 fathoms (Nos. 12725, 12792, 12885, and 12886). He said that it "appears
to stand next to A. [Adelometra] angustiradia of Carpenter's classification"- — that is,
to be a member of Carpenter's Savignyi group all the species in which belong to the
genera Craspedometra and Heterometra. In 1908 I published a note assigning magnicirra
to the genus Thalassometra, and remarked that it belongs to the Granulifera group
of Carpenter.

In two papers published in 1908 I listed Thalassometra magnicirra as a character-
istic oceanic species. In a revision of the family Thalassometridae published in Jan-
uary 1909 I listed Antedon magnicirra among the species I was unable to place satis-
factorily.

When I established Crotalometra later in 1909 I said that Antedon magnicirra
is a member of this genus, and in other papers published in the same year I compared
Crotalometra magnicirra with the new species C. rustica and C. sentifera. In a paper

100 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

on Kecent African crinoids published in 1911 Crotalometra magnicirra was listed, and
the synonymy and range were given.

In my description of Thalassometra marginalis published in 1912 I said that it is
closely related to Th. magnicirra, and in my memoir on the crinoids of the Indian
Ocean published later in the same year I listed Thalassometra magnicirra, giving the
synonymy and range.

In a paper on the crinoids of the British Museum published hi 1913 I listed six
specimens of Crotalometra magnicirra from stations Nos. 12885/6 and gave notes on
them; I also listed one specimen from station 12792. In my memoir on Antarctic
crinoids published in 1915 I noted that "Crotalometra magnicirra (Thalassometridae)
wurde bei East London, Kapland, in 540-810 m. (300-450 Faden) gefunden." In
my memoir on the unstalked crinoids of the Siboga expedition published hi 1918
magnicirra was inserted in the key to the species of Crotalometra and the range and
synonymy were given.

Dr. Hubert Lyman Clark hi his memoir on the echinoderms of South Africa
published in 1923 said that Crotalometra magnicirra "is not now in the South African
Museum, the original specimens having apparently all been retained at the British
Museum. It was taken hi 300^50 fathoms, 15-20 miles off the coast of Cape Colony,
near East London."

After examining the specimens in the British Museum, Prof. Torsten Gisle"n
wrote hi 1928 that in Crotalometra magnicirra the radials are concealed, the niter-
radial prominences of the centrodorsal are rather stout and large, and there are
usually 20 arms. He suggested that C. marginalis is probably a large specimen of
C. magnicirra.

In my report upon the crinoids of the John Murray Expedition to the Indian Ocean
hi 1933-34, published on January 1, 1937, I gave the range of Crotalometra magnicirra
and discussed its zoogeographical significance.

KOEHLERMETRA, gen. nov.

Antedon (part) P. H. CARPENTER, Philos. Trans. Roy. Soc., vol. 174, 1883, 1884, p. 921, and following

authors.

Actinometra (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, pp. 305, 306.
Thalassometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126.
Antedon (Crotalometra) KOEHLER and VANET, Bull. Mus. Hist. Nat. Paris, 1910, No. 1, p. 26.
Crotalometra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, pp. 8, 37.

Diagnosis. — A genus of Thalassometridae in which the arms are dorsally rounded to
the tip; the arms in fully developed individuals are 20 in number with the IIBr series
4(3+4), exceptionally 2; the division series and arm bases are smooth and without
spines; the first syzygy in arms following a IIBr 4(3+4) series is between brachials 2 + 3;
the cirri, which are very stout, are recurved distally with the outer segments carinate
or with dorsal spines; and the genital pinnules are not appreciably expanded. The
included species are large and very stout with the 20 arms about 150 mm. long, and the
cirri up to 55 mm. long with 30-50 segments.

Genotype. — Antedon porrecta P. H. Carpenter, 1888.

Geographical range. — From Ascension Island to the northern part of the Bay of
Biscay.

Bathymetrical range. — From 753 to 1,410 meters.

A MONOGRAPH OF THE EXISTING CRINOIDS 101

Remarks. — The species of the genus Koehlermetra are very robust, indeed the most
robust of all the species of Thalassometridae. In this respect they are parallel to the
species of Crinometra and Crossometra in the family Charitometridae, in which family
Pachylometra in a general way corresponds to Crotalometra.

The two species of Koehlermetra seem not to differ except in the number of cirrus
segments, and Hartlaub has suggested that they may represent varieties of the same
specific type. I have examined all the known specimens of both species, but un-
fortunately did not have time to study them in detail.

KEY TO THE SPECIES IN THE GENUS KOEHLERMETRA

a1. Cirri with 40-50 segments, 55 mm. long; 20+ arms 150 mm. long (Ascension Island to the Bay
of Biscay; 768-1,420 meters).. porrecta (p. 101)

a5. Cirri with about 30 segments; 20 arms (northern part of the Bay of Biscay to the Canary Islands;
753-1,410 meters) flava (p. 105)

KOEHLERMETRA PORRECTA (P. H. Carpenter)

[See vol. 1, pt. 2, pi. 34, figs. 1207-1209.]

Comalidc PARFAIT, Rapport sur la campagne scientifiquc du Talisman vn 18S3, 1884, p. 57 (45°59' N.,
6°29' W.; 1,480 meters). — FILHOL, La Nature, vol. 12, 1884, p. 329 (the figure of a multibrachiate
comatulid from off Rochefort, 1,500 meters); La vie au fond des mers, 1885, plate between pp.
10-11 (same). — DE FOLIN, Sous les mers, 1887, p. 335 (Gulf of Gascony, 1,480 meters). — A. H.
CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 48.

Antedon sp. P. H. CARPENTER, Philos. Trans. Roy. Soc., vol. 174, 1883, 1884, p. 921 (pentacrinoid from
near Ascension [Challenger station 344]; characters; comparison with Thaumatocrinus) , pi. 71,
fig. C; Bijdr. Dierk., Aft. 14, 1887, p. 48 (3 pentacrinoids from Ascension; comparison with the
Varna pentacrinoids).

Antedon porrecta P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 250 (descrip-
tion; Challenger station 344), pi. 52, figs. 3-5; Journ. Linn. Soc. (Zool.), vol. 24, 1891, p. 66
(comparison with [Stiremetra] lusitanica). — KOEHLER, Rev. Biol. Nord France, vol. 7, 1895, p. 475
(compared with Antedon flava, sp. nov.) ; Ann. Univ. Lyon, vol. 2G, Resultats scientifique de la
campagne du Caudan, June 1896, p. 97 (compared with/Zawa). — HAMANN, Bronn's Klassen und
Ordungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1582 (listed).— A. H. CLARK, Proc. Biol. Soc.
Washington, vol. 21, 1908, p. 126 (belongs to the genus Thalassometra) ; Proc. U. S. Nat. Mus.,
vol. 34, 1908, p. 225 (referred to Thalassomelra) ; Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18
(not placed in the revision of the Thalassomotridae). — HARTLATJB, Mem. Mus. Comp. Zool.,
vol. 27, No. 4, 1912, p. 285 (in the Granulifera group; doubtless different from granulifera) , p. 286
(referred by Clark to the Thalassometrinac) . — MORTENSEN, Handbook of the echinoderms of
the British Isles, 1927, p. 25.

Anledon mullispina (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 118,
last paragraph (3 pentacrinoids from station 344), pi. 14, figs. 5-7. — KIRK, Proc. U. S. Nat. Mus.,
vol. 41, 1911, p. 75, footnote (quoting [incorrectly] A. H. Clark), pi. 7, figs. 8-10 (from Car-
penter).

Actinometra pulchella (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, part 60, 1888, pp.
305, 306 (Talisman record; off Rochefort, 1,500 meters; reference to Filhol's figure).

Actinomelra, sp. W. MARSHALL, Die Tiefsee u. ihr Leben, 1888, pi. 4; figure of a multibrachiate comat-
ulid (from Filhol, with identification by Carpenter).

Thalassometra porrecta A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (Antedon
porrecta should be assigned to Thalassometra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (same);
Amer. Nat., vol. 42, 1908, No. 500, p. 542 (characteristic oceanic species); Gcogr. Journ., vol. 32,
No. 6, 1908, p. 603 (same).

Antedon (Crotalometra) porrecta KOEHLER and VANLY, Hull. Mus. Hist. Nat. Paris, 1910, No. 1, p. 26
(collected by the Travailleur or the Talisman), p. 32 (45C19' N., 6°29' W.; 1,480 meters).

Crotalometra porrecta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 8 (west coast of Africa),
p. 37 (near Ascension, 420 fathoms; also Bay of Biscay, 1,480 meters); Smithsonian Misc. Coll.,

102 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

vol. 61, No. 15, 1913, p. 46 (published references to specimens in the B. M.; Challenger Sta. 344;
characters of the cirri); Unstalked crinoids of the St'6o<?a-Exped., 1918, p. 148 (in key; range),
p. 149 (references); The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range);
GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 28, footnote. — MORTENSEN, Handbook of the
echinoderms of the British Isles, 1927, p. 25 (localities; in key). — GISLEN, Ark. Zool., vol. 19,
No. 32, Feb. 20, 1928, p. 7, No. 30 (notes); Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45,
No. 11, 1934, p. 23.

Thalassometra multispina (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47
(the pentacrinoid from Challenger station 344).

Crotalometra porrceta GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 194 (supposed larva).

Diagnostic features. — The cirri have 40-50 segments and are 55 mm. long; the 20 +
arms are 150 mm. long.

Description. — The centrodorsal is a thick disk with the interradial angles slightly
produced.

The cirri are XX-XXX, 40-50, long and stout (according to the figure about 55
mm. long). The longest proximal segments are about as long as broad, but most of the
segments are broader than long and are produced on the dorsal side into a strong
pointed process which at first involves only the distal portion but later rises from most
of the dorsal surface.

The radials are invisible except in the interradial angles of the calyx. The elements
of the IBr series are rather convex and are slightly tubercular at the articulation
between them. The IBri are short, laterally united, and the IBr2 (axillaries) are
broadly pentagonal, about two and one-half tunes as long as the IBr!. The IIBr
series are 4(3 + 4) and the IIIBr series, when present, are 3(2+3). The elements of
the division series are very convex and have their sides flattened against each other,
but this is less marked on the outside of the postradial series where the hypozygals of
the IIBr and IIIBr axillaries and the second brachials are kept apart by the large
pinnule on the segment preceding.

There are 20+ arms, probably 150 mm. long. They are composed of compressed
triangular brachials which become elongated and quadrate distally. From the four-
teenth brachial onward the middle of the distal edge of each ossicle is raised into a
strong plate the front face of which is hollowed. Beyond the eleventh or sixteenth
brachial this gives place to an overlap of the usual character that extends far out on
the arm.

Syzygies occur between brachials 2 + 3, again from between brachials 7 + 8 to
between brachials 15+16, and distally at intervals of from 4 to 13 muscular articula-
tions, the intervals becoming shorter toward the end of the arms.

PI and the preceding pinnules on the IIBr2 and IIIBri are tolerably equal with
about 15 stout segments the five lowest of which are rather broad and trihedral with
flattened outer faces and the inner sides slightly beveled away. Pa and P2 are smaller
with fewer segments of which the basal are more compressed. The pinnules following
are larger again with broader lower segments the outer edge of which is expanded
toward the ventral side. This feature gradually dies away in the outer parts of the
arms, and the segments become more elongated.

The disk is 15 mm. in diameter, slightly incised and well plated like the brachial
ambulacra. The pinnule ambulacra have well defined side plates and small sacculi.

The color in alcohol is dark gray-brown.

A MONOGRAPH OF THE EXISTING CRINOIDS 103

Notes. — The preceding description is adapted from the original description by
Carpenter, with a few additions from his figures. At the British Museum in 1910 I
examined one large and two small specimens from the type material. In the larger
specimen the cirri are XIV, from 50 to 54 mm. long; the eighth or ninth is a transition
segment. I noted that this species is remarkable for the great size and stoutness of its
cirri.

These specimens were later examined by Prof. Torsten Gislen, who suggested that
perhaps there were muscles in the most proximal syzygies.

Localities. — Challenger station 344; south Atlantic, near Ascension Island (lat.
7°54'20" S., long. 14°28'20" W.); 768 meters; volcanic sand; April 3, 1876 [P. H.
Carpenter, 1884, 1887, 1888, 1891; Koehler, 1896; A. H. Clark, 1908, 1909, 1911, 1913,
1918, 1923; Kirk, 1911; Hartlaub, 1912; Gislen, 1924, 1928, 1934; Mortensen, 1927]
(3, B. M.).

Talisman; Bay of Biscay; west of Rochefort (lat. 45°19' N., long. 6°29' W.);
1,420 meters; August 30, 1883 [Parfait, 1884; Filhol, 1884; de Folin, 1887; Marshall,
1888; A. H. Clark, 1911, 1918, 1923; Koehler and Vaney, 1910; Mortensen, 1927].

Geographical range. — Eastern Atlantic from the vicinity of Ascension Island
northward to the Bay of Biscay

Bathymetrical range. — From 768 to 1,420 meters.

History. — In his account of the scientific investigations of the French steamer
Talisman in 1883, published in 1884, Capt. Jacques Theophile Parfait, the commanding
officer, mentioned a comatulid from lat. 45°59' N., long. 6°29' W., in 1,480 meters.
Henri Filhol in 1884 published a figure of a multibrachiate comatulid from off Rochefort
in 1,500 meters, republishing the same figure in 1885. The Marquis de Folin in 1887
referred to a comatulid from the Gulf of Gascony in 1,480 meters.

Dr. Philip Herbert Carpenter in 1884 described and figured a pentacrinoid larva
that had been dredged by the Challenger in lat. 7°54'20" S., long. 14°28'20" W. in 420
fathoms which he identified as the young of Antedon (Thalassometra) multispina, but
which almost certainly is the young of this species (see Part 2, p. 521). In 1887 he
compared this with some pentacrinoids from the Varna expedition which are the young
of Heliometra glacialis.

In the Challenger report on the comatulids published in 1888 Carpenter described
Antedon porrecta in detail and figured it. The three pentacrinoids from station 344
he described and figured under Antedon (Thalassometra') multispina, and Filhol 's
figure of a multibrachiate comatulid from off Rochefort he identified as Actinometra
pulchella (= Neocomatella europaea; see Part 3, p. 153). He noted that the length of
the cirri and the strong dorsal processes on their numerous segments are good distinctive
characters, and that one cirrus has been broken and subsequently regenerated. He
said that the characters of the pinnules of porrecta are the same as those of Antedon
(Charitometra) basicurva and its allies, though in a less marked degree. The lower
segments of the genital pinnules are expanded toward the ventral side so as to protect
the genital glands, which have but a slight covering of anambulacral plates, while the
first two pinnules have massive lower segments with the outer side flattened just as
in Antedon (Aglaometra) valida and incerta.

In 1888 Dr. William Adolf Ludwig Marshall republished Filhol's figure which he
identified as Actinometra sp., following Carpenter. In 1891 Carpenter compared

104 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

porrecta with Antedon (Stiremetra) lusitanica, and in 1895 and 1896 Prof. Rene Koehler
compared it with his new species Antedon (Crotalometra) flava.

In a paper published on April 11, 1908, I assigned porrecta to my new genus
Thalassometra described in the preceding year, repeating this in a paper published on
May 14. In two other papers published in the same year Thalassometra porrecta was
listed as a characteristic species of the oceanic fauna. In a revision of the family
Thalassometridae published in 1909 I included Antedon porrecta among the species
I was unable to allocate satisfactorily.

In 1910 Profs. Rene Koehler and Clement Vaney recorded Antedon (Crotalometra)
porrecta from a Travailleur or Talisman station in lat. 45°19' N., long. 6°29' W. in
1,480 meters, August 30, 1883. The only comatulid dredged at this station was one
specimen of this species; with this there were 10 specimens and numerous fragments of
Annacrinus m/ville-thomsoni. Crotalometra porrecta, therefore, was the "comatule"
mentioned by Captain Parfait and the Marquis de Folin, and figured by Filhol and
Marshall. Captain Parfait gave the latitude as 45°59' N.; as Filhol gave the locality
as off Rochefort this is probably correct.

In a paper on the crinoids of the coasts of Africa published in 1911 I included
Crotalometra porrecta and gave the synonymy and range.

Speaking of the pentracrinoids from Challenger station 344 Dr. Edwin Kirk wrote:

Mr. A. H. Clark says that these three specimens identified by Carpenter as A. multispina do no'
appear to belong to the same species and, indeed, may be referable to different groups. Furthermore
he states that the figures are inaccurate. It scarcely seems probable that the draftsman could go far
wrong in regard to the cohnnnals, however, and the evidence of fusion having taken place, though by
no means conclusive, still seems fairly good.

I told Dr. Kirk that these pentracrinoids appear to belong not to multispina but
to porrecta, in a different generic group. I did not say that the figures were inaccurate
but that it was inaccurate to interpret them as indicating that the centrodorsal is
composed of more than a single ossicle.

In his memoir on the comatulids of the Blake expedition published in 1912 Dr.
Clemens Hartlaub discussed this species in relation to the other species in Carpenter's
Granulifera group. He said he had the impression that Carpenter here, as elsewhere,
had made too many species, and he suggested that Antedon angusticalyx, A. inaequalis,
and A. distincta were really synonymous with Pourtales' A. gmnulifera, though the
doubtless different A. porrecta and A. multispina should be retained. He regarded
Koehler's Antedon flava as probably a synonym of porrecta.

In a paper on the crinoids of the British Museum published in 1913 I noted that
I had examined one large and two small specimens of Crotalometra porrecta from Challen-
ger station 344 and gave notes on them. In my report on the unstalked crinoids of the
Siboga expedition published in 1918 porrecta was included in the key to the species of
Crotalometra, and the synonymy and range were given. This information was repeated
in my report on the crinoids of the Ingolj expedition published in 1923.

Prof. Torsten Gislen in 1924 discussed certain points in the structure and develop-
mental stages of the three pentacrinoids from Challenger station 344, which he identified
as the young of Crotalometra porrecta with a query.

In his handbook of the echinoderms of the British Isles published in 1927 Dr.
Theodor Mortensen inserted porrecta in his key to the east Atlantic species of Crotalo-

A MONOGRAPH OF THE EXISTING CRINOIDS 105

metra and gave the range of the species. Professor Gislen, after examining the speci-
mens of this species in the British Museum, suggested in 1928 that perhaps the proxi-
mal syzygies contain muscles, and in 1934 he discussed the brachial structure at length.

KOEHLERMETRA FLAVA (Koehler)

[See vol. 1, pt. 2, figs. 210, p. 150, 531, 532, p. 287.]

Antedon flava KOEHLER, Rev. biol. nord France, vol. 7, 1895, p. 475 (description; Caudan station 4);
Ann. Univ. Lyon, Resultats scientifique dc la campagne du Caudan, June 1896, pp. 27, 97 (de-
tailed description; station 4), pi. 2, figs. 20, 21. — GRIEO, Bergens Mus. Aarbog for 1903, No. 5,
1904, p. 35. — A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (belongs to the
genus Thalassometra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (referred to Thalassometra) ;
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (not placed in the revision of the Thalassoruetri-
dae). — HARTLAUB, Mem. Mus. Cornp. Zool., vol. 27, No. 4, 1912, p. 285 (belongs to the Granu-
lifera group), p. 285, footnote (close relationship with porrecta). — W. DE MORGAN, Journ. Mar.
Biol. Assoc., new ser., vol. 9, No. 4, March 1913, pp. 539, 540 (Huxley station 13). — MORTENSEN,
Handbook of the echinoderms of the British Isles, 1927, p. 25.

Thalassometra flava A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (should be as-
signed to Thalassometra); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (same); Amer. Nat., vol.
42, No. 500, 1908, p. 542 (characteristic oceanic species); Geogr. Journ., vol. 32, No. 6, 1908, p.
603 (same).

Anlcdon (Crotalometra) flava KOEHLER AND VANEY, Bull. Mus. Hist. Nat. Paris, 1910, No. 1, p. 26
(collected by the Travailleur or the Talisman), p. 31 (locality).

Crotalometra flava A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 7 (northwestern coast of
Africa), p. 37 (synonymy; south of the Canary Islands, 882 meters; also Bay of Biscay, 1,480
[error for 1,410] meters); Unstalked crinoids of the iSiboja-Exped., 1918, p. 148 (in key; range), p.
149 (references); The Danish Ingolf-Expcd., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range). —
MORTENSEN, Handbook of the echinoderms of the British Isles, 1927, p. 25 (localities; in key). —
KOEHLBR, Echinodermes des mers d'Europe, vol. 2, 1927, p. 133 (habitat).

Diagnostic features. — -The cirri have about 30 segments.

Description. — The centrodorsal is flattened. In one of the specimens it is very
large, its diameter reaching 6 mm. In the other it is much smaller with a diameter of
only 3 mm.

The cirri in the latter are XXII, in the former XXVI, with many broken off at
the base. They have about 30 segments of which the length increases progressively
from the first to the sixth, which is the longest, twice as long as broad; after the tenth
the segments become a little broader than long. On the sixth the distal border on the
dorsal side begins to rise and forms a point that becomes more marked on the segments
following and is continued to the end of the cirri.

The radials are completely concealed. The IBri are partially concealed and are
in close contact laterally. The IBr2 (axillaries) are entirely free laterally. The IIBr
series are 4(3+4). The first two elements of the IIBr series rise on the dorsal side
into a well marked blunt tuberosity.

The 20 very stout arms are flattened laterally. At the proximal angle the lower
border of each brachial is produced into a broad_process which accompanies the corre-
sponding pinnule.

Syzygies occur between brachials 2+3, again from between brachials 19 + 20 to
between brachials21 + 22, and distally at intervals of from 7 to 13 muscular articulations.

PD and PI are flattened and prismatic and are composed of 16 or 17 segments of
which the proximal are very broad. The two following pinnules are smaller and shorter,

106 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and the number of their segments does not exceed 10. The succeeding pinnules are
larger and have 15 segments; their length is almost equal to that of PD and PI.

In the living animal the cirri and arm bases are bright saffron yellow which becomes
deeper and passes into light brown on the outer half of the arms. Koehler said that
this coloration is in part preserved in alcohol.

Notes. — Dr. Clemens Hartlaub wrote that Antedonfiava by virtue of the position
of the first brachial syzygy between brachials 2 + 3 is in the closest agreement with
A. porrecta which alone among the species of the Granulifera group possesses this
feature. He said that the chief difference between flava and porrecta — the length of
the cirri — did not seem so important to him as it had to Koehler. The cirri of flava are
much shorter than those of porrecta, about 35-38 mm. long. According to Carpenter's
figure the longest cirrus of porrecta is somewhat less than 55 mm. long and another is
barely 45 mm. long. The number of cirri in the two species does not differ — in porrecta
XX-XXX, w flava XXV-XXVI. The number of cirrus segments is less in flava (about
30) than in porrecta (40-50) . The form of the outer cirrus segments according to the
figures is the same in both. The centrodorsals of the two species appear to show no
noteworthy differences. A "tuberosite' mousse assez marque'e" on the first two elements
of the IIBr series that Koehler describes in flava appears, according to Carpenter's
figure, to be lacking in porrecta. There are some differences in the position of the
second and following syzygies. The number of segments in PD is the same in each
(16-17 and about 15). In the form of the lower segments of PD there is apparently close
correspondence. This appears to be the case also in the relationship of the following
pinnules. In view of the great variability of the species of Antedon (in the old sense)
it seemed to Hartlaub that the slight differences between porrecta and flava are scarcely
sufficient to justify the establishment of a new species.

Localities. —Huxley station 13; off Brittany (lat. 48°07'30" N., long. 8°13'00" W.);
753 meters; sand, mud, and hard ground; August 1906 [de Morgan, 1913; A. H. Clark,
1918, 1923; Mortensen, 1927; Koehler, 1927].

Caudan station 4; Bay of Biscay, west of La Rochelle (lat. 45°57' N., long. 6°21'
W.); 1,410 meters; coral and mud; August 21, 1895 [Koehler, 1895, 1896, 1927; Grieg,
1904; A. H. Clark, 1908, 1909, 1911, 1918, 1923; Hartlaub, 1912; de Morgan, 1913;
Mortensen, 1927] (1, U.S.N.M., 35583).

Talisman; south of the Canary Islands (lat. 25°39' N., long. 18°22' W.); 882
meters; July 9, 1883 [Koehler and Vaney, 1910; A. H. Clark, 1911].

Geographical range. — From the northern part of the Bay of Biscay south to the
Canary Islands.

Bathymetrical range. — From 753 to 1,410 meters.

History. — Prof. Eene Koehler described Antedon flava in 1895 from two specimens
dredged by the French steamer Caudan at station 4 in August of the same year. He
said that A. flava belongs to the Granulifera group; like A. porrecta it has a syzygy in the
second brachial (that is, the first syzygy is between brachials 2+3), but is distin-
guished at a glance by the cirri, which are much shorter. In 1896 he gave a brief but
interesting account of the dredge haul at which the specimens were captured, which was
very near the spot where the Talisman had found Annacrinus wyville-thomsoni in great
abundance. He said that A. flava is remarkable for its superb sulphur yellow color,

A MONOGRAPH OF THE EXISTING CRINOIDS 107

which unfortunately fades strongly in alcohol. He republishcd the original description,
adding nothing new, and figured a cirrus and a portion of an arm with four pinnules.

In a discussion of the adambulacral plates and other details of the pinnules of
north Atlantic comatulids published in 1904 Dr. James A. Grieg mentioned that he
had had no opportunity to examine the pinnules of Antedon flam, but presumably they
are quite different from those of the other species since it belongs to the Granulifera
group.

In a paper published on April 11, 1908, and in another published on May 14, I
assigned Antedon flava to the genus Thalassometra, and in two papers published later
in the same year Thalassometra flava was given as a characteristic oceanic species. In
my review of the family Thalassometridae published in 1909 Antedon flava was listed
among the species I was unable to place satisfactorily.

In 1910 Profs. Rene Koehler and Clement Vaney recorded without comment two
specimens of Antedon (Crotalometra) flava from lat. 25°39' N., long. 18°22' W., in 882
meters, that had been dredged by the French steamer Talisman. In my paper on the
crinoids of the coasts of Africa published in 1911 I listed Crotalometra flava, giving the
synonymy, the African locality, and the range.

In his memoir on the comatulids of the Blake expedition published in 1912 Dr.
Clemens Hartlaub compared this species in detail with C. porrecta, coming to the con-
clusion that the differences between them scarcely sufficed for the establishment of a
new species.

In 1913 Dr. W. de Morgan recorded Antedon flava from Huxley station 13, his
specimens having been identified by Professor Koehler.

In my memoir on the unstalked crinoids of the Siboga expedition published in
1918 I included flava in my key to the species of the genus Crotalometra and gave the
synonymy and range, and in my memoir on the crinoids of the Ingolj expedition
Crotalometra flava was listed, with the range.

In 1927 Professor Koehler included an account of Crotalometra flava in his memoir
on the echinoderms of the European seas, and Dr. Theodor Mortensen mentioned it,
with its range, in his handbook of the echinoderms of the British Isles.

Genus AGLAOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 11, pt. 32, 1884, p. 57, and following

authors.

Thalassometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.
Crotalometra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 404.
Aglaometra A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47 (no diagnosis, and no

type mentioned; 2 species cited under this generic name, Aglaometra valida and A. incerta);

Unstalked crinoids of the 5(6o</a-Exped., 1918, p. 146 (in key; range), p. 163 (key to the included

species). — GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7; Kungl. Fysiogr. Sallsk. Handl.,

new ser., vol. 45, No. 11, 1934, p. 18.

Diagnosis. — -A genus of Thalassometridae in which the arms are dorsally rounded
to the tips; the arms are 10 in number; the IBr series and arm bases are rounded dorsally,
not carinate, smooth or almost so, without numerous and conspicuous spines; the cirri
are recurved distally, the short outer segments carinate or bearing spines dorsally; there
is no appreciable expansion of the genital pinnules; and the size is large, the arms being
90-150 mm. long and the cirri 45-90 mm. long with 59-70 segments.

108 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Geographical range. — From the northern Philippines to the Moluccas and the
Kermadec Islands, north of New Zealand.

Bathymetrical range. — -From 457 to 1,165 (?1,264) meters.

Thermal range.— From 4.17° to 10.2° C.

Remarks. — -There appear to be four readily recognizable species in this genus. Of
the six species heretofore recognized, valida, eupedata, incerta, propinqua, vera, and sul-
cata, two are considered synonyms herein, eupedata a synonym of valida and vera a
synonym of propinqua.

The genus Aglaometra appears not to differ appreciably from Stiremetra except in
the greater size of the included species, which have the IBr series and lower brachials
more broadly rounded dorsally.

History. — The first known species of this genus were described as Antedon valida
and A. incerta by Dr. P. H. Carpenter in his report on the comatulids of the Challenger
expedition published in 1888. These species were transferred to my new genus Tfutlasso-
metra upon its establishment in 1907. In my revision of the family Thalassometridae
published on January 9, 1909, Antedon incerta and A. valida were included in the list
of species I was unable to place satisfactorily. On May 13, 1909, I established the
new genus Crotalometra with the genotype 0. eupedata, sp. nov., and referred Antedon
valida and A. incerta to it, together with Bell's Antedon magnicirra. The generic name
Crotalometra had, however, appeared previously in the description of a new species,
C. rustica, which thereby became the genotype (see page 92). In 1911 I described
Crotalometra propinqua, and in 1912 C. suhata and C. vera. In my memoir on the
crinoids of the Indian Ocean published later in 1912 Crotalomdra eupedata, C. propinqua,
C. valida, and C. incerta were listed and their synonymies and ranges were given. In a
paper on the crinoids of the British Muesum published in 1913, under the heading,
"Genus Aglaometra A. H. Clark," I gave notes on Carpenter's specimens of A. valida
and A. incerta. Of these two, A. valida should be taken as the genotype. In my
memoir on the unstalked crinoids of the Siboga expedition published in 1918 Aglaometra
was included in the key to the genera of the subfamily Thalassometrinae, and Aglao-
metra eupedata, A. sulcata, A. valida, A. vera, A. propinqua, and A. incerta were listed.

KEY TO THE SPECIES IN THE GENUS AGLAOMETRA

a1. Ossicles of the division series and lower brachials everywhere in close lateral contact.
b1. Cirri long and stout, more than half the arm length.

c1. Large and stout; proximal portion of the animal strongly compressed, the lateral profiles
from the base of the centrodorsal nearly straight, the two sides making with each other an
angle of approximately 45° when the division series are all in contact; arms 100-150 mm.
long, cirri 80-90 mm. long with 65-66 segments (from Mindanao to Celebes; 457-1,165

[71,264] meters) valida (p. 109)

c2. Somewhat smaller and less stout; proximal portion of the animal broadly rounded, the profiles
of the axillaries making with each other an angle of about 90°, but the arms being nearly
parallel; arms 90 mm. long, cirri 50 mm. long with 70 segments (Kermadec Islands; 1,152

meters) incerta (p. 114)

62. Cirri shorter and more slender, less than half the arm length; arms 130 mm. long, cirri 45-60

mm. long with 59-69 segments (Philippines and Moluccas; 567-960 meters) _propinqua (p. 116)

a2. Distal angles of the IBn and proximal angles of the axillaries and the corresponding angles of the

first two brachiala and of the elements of the first syzygial pair widely cut away, forming large

and prominent rhombic water pores; the edges of the ossicles bordering these water pores are

more or less everted and coarsely denticulate, or bear a few coarse spines; arms about 115 mm.

A MONOGRAPH OF THE EXISTING CRINOIDS 109

long, cirri 60-65 mm. long with 63-64 segments (west of Waigeu to northern Celebes; 457-798
meters). sulcata (p. 118)

AGLAOMETRA VALIDA (P. H. Carpenter)

PLATE 12, FIGURE 37; PLATE 13, FIGURES 38,39
[See also vol. 1, pt. 2, fig. 225, p. 179.]

Antedon valida P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 104 (description;
station 214), pi. 15, figs. 5-8. — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131
(systematic and bathymetrical relationships), p. 134 (size compared with that of [Thalassometra]
agassizii). — HAMANN, Bronn's Klassen und Ordnungen des Tier-Ueiohs, vol. 2, Abt. 3, 1907,
p. 1578 (listed). — A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (not placed
in a revision of the Thalassometridae) ; Proc. U. S. Nat. Mus., vol. 36, 1909, p. 404 (referred to
Crotalometra) ; Crinoids of the Indian Ocean, 1912, p. 33 (of P. H. Carpenter, 1888= Crotalometra
valida).

Thalassomelra valida A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3. 1907, p. 360 (listed).

Crotalometra eupedala A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 404 (description; Alba-
tross station 5236; also station 5116); Proc. U. S. Nat. Mus., vol. 39, 1911, pp. 549, 550 (cirri
compared with those of C. propinqua), p. 551 (small 11-armed specimen doubtfully referred to
this species in 1909 is really [Oceanomeira] annandalei) ; Crinoids of the Indian Ocean, 1912, p. 209
(synonymy; locality).

Crotalometra valida A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 33 ( = Anledon valida P. H.
Carpenter, 1888), p. 209 (synonymy; locality).

Aglaometra valida A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47 (published refer-
ences to specimens in the B. M. ; Challenger station 214; comparison with A. eupedata); Un-
stalked crinoids of the Siboga-Exped., 1918, p. 163 (in key; range), p. 164 (notes; station 122),
p. 273 (listed).

Aglaometra eupedata A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47 (comparison
with t>a!ida): Unstalked crinoids of the Siboga-Exped., 1918, p. 163 (in key; range), p. 164 (refer-
ences).

Diagnostic features. — The elements of the IBr series and lower brachials are in
close lateral contact; the proximal portion of the animal is strongly compressed, the
lateral profiles from the base of the centrodorsal being nearly straight and making with
each other an angle of approximately 45° when the division series and arm bases are
in contact; and the cirri are long and stout, much more than half the length of the arms.
The 10 arms are 100-150 mm. long, and the cirri are 80-90 mm. long with 65-66
segments.

Description. — The centrodorsal is large and conical, with the ventral interradial
angles produced. The cirrus sockets are arranged in 10 columns, one or two to a
column. The columns are situated along the outer borders of the radial areas and are
separated in the midradial line by a bare and somewhat excavated triangle which at
the base, just below the radials, is as broad as, or broader than, the adjacent cirrus
sockets.

The cirri are about XV, about 65, up to 80 mm. in length; the seventh-twelfth
segments are considerably longer than broad, but from the twenty-fifth onward the
segments are short and broad with a strong dorsal spine.

The radials are just visible. The elements of the IBr series are strongly convex
in the middle of the articulation between them. The borders of the radials, the ele-
ments of the IBr series, and the lowest brachials are fringed with strong spines. The
IBr2 (axillaries) and first brachials have straight edges and flattened sides.

HO BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The 10 arms are probably about 100 mm. long. The brachials are triangular,
slightly overlapping, the later somewhat compressed laterally. The second brachials
and the hypozygals of the first syzygial pairs are flattened on the inner side only. The
line of junction between the first two brachials is somwehat tubercular.

Syzygies occur between brachials 3+4, again at about the thirteenth brachial,
and distally at intervals of from 5 to 16 muscular articulations.

P, is large and stout; the first eight segments have broad and flattened outer sides,
and the third, fourth, and fifth have the inner edges bent upward and somewhat thick-
ened, but in the next following these are sharpened and form a keel. Pa is similar but
smaller, with the outer side flattened. The pinnules of the next two pairs have broad
and carinate lower segments, and the later pinnules are more styliform with the two
basal segments expanded and trapezoidal and those following elongated.

The disk is 11 mm. in diameter, thickly covered with plates which extend out onto
the arms at the sides of the ambulacra, and also over the gonads. The pinnule ambulacra
have well-defined side- and covering-plates. Sacculi are very rare.

Notes. — The preceding description is adapted from that of Carpenter, with a few
additions from his figures. In 1910 I examined two of Carpenter's specimens in the
British Museum. This is a large species, resembling in a general way A. eupedata;
the distal edges of the radials and the lateral edges of the IBr series and first two brachials
are conspicuously dentate with fine well separated teeth.

In the specimens from Siboga station 122 the dorsal pole of the centrodorsal is more
blunted than in Carpenter's specimens, and is studded with numerous small low tuber-
cles. The cirrus sockets are in 10 columns which are interradially in apposition, though
well separated in the midradial line. There is usually only a single functional cirrus
socket to a column. The more distal obsolete cirrus sockets develop conical tubercles
of which the axes are parallel to the dorsoventral axis of the animal. These tubercles
are proportionate in size to the size of the cirrus socket they occupy; thus below the
functional socket in the columns there is in each radial area a double row of tubercles
of diminishing size which continues to the dorsal pole, there merging with the small
polar tubercles.

There are three cirri remaining which are composed of 45 (one) and 61 (two)
segments; in the first the transition segment is the ninth, in the two others the eighth,
the cirri decrease slightly in diameter to the transition segment, and in lateral view
increase in diameter on the short distal segments. The longest cirrus segment (the
transition segment) is about twice as long as broad.

The radials are visible as short and broad, more or less irregular, tubercles between
the centrodorsal and the IBri ; one or two tubercles springing from them are visible in
the angles of the calyx over the ends of the basal rays, and there may be a smaller
tubercle between these and the central tubercle. The central tubercle is indicated in
Carpenter's figure but is not clearly shown.

The ends of the basal rays are visible as small low rhombic tubercles in the inter-
radial angles; they are more or less obscured by the tubercles arising from the radials
above them and by the cirri beneath.

The proximal border of the IBri is turned outward and more or less scalloped;
the median third of this border is straight and parallel with the proximal border of the
centrodorsal; the lateral thirds slant outward and upward and are slightly concave;

A MONOGRAPH OF THE EXISTING CRINOIDS 111

the edge of this eversion is thickened and smooth. The lateral portions of the distal
border of the IBrj are also everted, but not nearly so prominently as the proximal
border. The IB^ are verly slightly longer than those in the Challenger specimens,
and the distal border is not quite so much incised; this undoubtedly is due to the smaller
size of these individuals.

The IBr2 (axillaries) are not quite twice as broad as long; the proximal edge is
slightly straighter than in the Challenger specimens, and is slightly everted. The
lateral borders of the elements of the IBr scries and of the first brachials, and the inner
borders of the first two brachials, are laterally produced.

PI is greatly enlarged with 12 or 13 segments of which the first eight or nine are
sharply flattened on the outside, the ventral border being somewhat produced; the
second and third segments are strongly carinate on the inner ventral border, especially
the third, but from this point on the carination rapidly diminishes in extent, disappear-
ing three or four segments later. On the second segment this carination is parallel to the
dorsoventral plane, but it gradually becomes recumbent so that on the fourth it is at
right angles to this plane.

The brachials beyond the tenth are triangular, about as long as broad, with very
finaly spinous distal margins. The dorsal line of the arms is smooth in profile.

A specimen from Albatross station 5256 was described as a new species under the
name of Crotalometra eupedata in the following terms.

The centrodorsal is large and conical, 5 mm. broad at the base and 5 mm. high, with
the bare polar area forming the apex of the cone. The cirrus sockets are arranged in
10 columns of one or two each, which are usually succeeded by one or two obsolete
and more or less obliterated ones. The columns are on the outer borders of the radial
areas so that the columns of adjacent radial areas are in close apposition while the
two columns in each area are separated by a median space which is about equal to
their own width.

The cirri are X-XX, 66, 90 mm. in length. The first 3 segments are two and
one-half times as broad as long, the fourth is twice as broad as long, the fifth is half again
as broad as long, and the sixth is slightly longer than broad. The seventh is a transition
segment, dull in the proximal three-fourths but highly polished and laterally compressed
in the distal fourth, not quite twice as long as broad. The eighth-eleventh or -twelfth
segments are about twice as long as broad, and those following gradually decrease in
length, becoming about as long as broad at about the twentieth, and twice as broad
as long distally. After the fifteenth the distal dorsal edge of the segments begins to
project slightly, though this is scarcely noticeable until the twentieth is reached, after
which it increases in height, becoming more sharply rounded in end view and arising
from the whole dorsal surface of the segment, so that the dorsal profile of the terminal
third of the cirri is strongly serrate. The opposing spine is a blunt tubercle with the
apex subterminal, arising from the entire dorsal surface of the penultimate segment.
The terminal claw is very long and slender, twice as long as the penultimate segment,
and only slightly curved. All of the cirrus segments have the distal ends all around
slightly projecting and very finely spinous, making the cirri rough to the touch. This
projection is slightly more marked on the ventral side than laterally.

The disk is covered with small plates which are very thickly set near the ambulacral
grooves but become more scattered toward the periphery in the interambulacral areas.

112 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The ambulacra! grooves themselves are bordered with large regular plates. The
plating on the brachial and pinnule ambulacra is very highly developed. The perisome
of the arms is completely covered with rather large plates so that the arms and pinnules,
when the covering plates are closed down, are completely encased in a calcareous
covering.

The ends of the basal rays are visible as small, though prominent, tubercles in
the interradial angles of the calyx.

The radials are of uniform width all around the calyx, short, somewhat over four
times as broad as long, with the distal border set with small scattered spines. The
IBrj are short, of uniform height, with the proximal border convex and the distal
concave, about three times as broad as long; the proximal edge is slightly prominent,
and the lateral edges are in very close apposition and rather prominently everted, the
crest of the resultant ridge being finely spinous. The IBr2 are broadly pentagonal, about
twice as broad as long, with the lateral edges about as long as those of the IBri and
everted and finely spinous like those of that ossicle. Like the IBri and the first two
brachials it bears a single small but rather prominent rounded tubercle near each
lateral margin.

The 10 arms are stout and rugged but becoming slender distally, 150 mm. in length.
The first brachials are longer exteriorly than interiorly, with the distal border concave,
the interior edges closely united, and the exterior edges everted and spiuous like the
lateral edges of the preceding ossicles. The second brachials are about twice as large
as the first, irregular hi shape, with the proximal border strongly convex; they are in
close apposition with then- neighbors and strongly flattened against them, and both the
exterior and interior edges are everted and spinous. The first syzygial pair (composed of
brachials 3+4) is half again as broad as long, laterally flattened both exteriorly and in-
teriorly, with the lateral edges less strongly everted than those of the preceding ossicles.
The succeeding five brachials are approximately oblong, about 3 times as broad as
long and rather strongly tubercular, those after the twelfth becoming triangular and
about as long as broad, this proportion remaining unchanged until near the arm tips
where, the brachials become wedge-shaped and somewhat longer. The distal edges
of the brachials in the outer two-thirds of the arms are overlapping and finely spinous.

Syzygies occur between brachials 3+4, again from between brachials 14+15 to
between brachials 17+18, and distally at intervals of from 4 to 10 (usually 6 or 7)
muscular articulations.

PI is large and very stout, strongly flattened exteriorly, composed of 17-18 seg-
ments all of which are broader than long; the pinnule tapers rather rapidly after the
proximal third so that the terminal portion is delicate with very small segments. P2
is 7 mm. long, stout basally, though not nearly so stout as PI; it tapers rapidly, so
that the distal half is slender, and is composed of 14 segments of which the first 3 are
broad, the fourth is about as long as broad, and the remainder are somewhat longer
than broad. The first 6 segments of Pt have the distal side very strongly concave,
forming 2 sharp keels, one external along the flattened outer side, the other internal;
the external keel is armed with fine spines. The distal segments are prismatic, with
the angles somewhat produced. P2 has a similar double carination but, while the
exterior keel is much lower, it persists in a raised and very spinous line to the tip of the
pinnule; the ends of the distal segments are much more spmous than is the case in

A MONOGRAPH OF THE EXISTING CRINOIDS 113

PI. P3 is 6 mm. long, more slender than P2, bearing about the same proportion to that
pinnule as it does to PI, with 12 segments which at first are broad, becoming about as
long as broad on the fifth, and longer than broad distally. The pinnule is strongly
prismatic, the ridges and the distal ends of the segments being spinous, but the 2 basal
keels are only slightly marked. P4 and the following pinnules are similar to P3 but
slightly more slender with the segments proportionately slightly longer. The distal
pinnules are 12 mm. long, rather stout, strongly prismatic, with 18 segments of which
the first is crescentic, the second is strongly trapezoidal, about as broad as the greater
(proximal) length, and the remainder are about half again as long as broad. The
external ridge is somewhat produced and is finely spinous.

Of the three specimens from Meriado Bay, Celebes, one is fragmentary with the
cirri stout and about 80 mm. long, and the other two are small, one with the cirri
about 65 mm. long.

Localities.— Albatross station 5236; off the east coast of Mindanao, Philippines;
Magabao Island (S.) bearing N. 85° W., 9.1 miles distant (lat. 8°50'45" N., long. 126°
26'52" E.); 903 meters; bottom temperature 5.1° C.; fine gray sand; May 11, 1908
[A. H. Clark, 1909, 1911, 1912, 1913, 1918] (1, U.S.N.M., 25462).

Challenger station 214; off the Meangis Islands, southeast of Mindanao, Philip-
pines (lat. 4°33' N., long. 127°06' E.); 914 meters; bottom temperature 5.44° C.;
blue mud; February 10, 1875 [P. H. Carpenter, 1888; Hartlaub, 1895; A. H. Clark,
1907, 1909, 1912, 1913, 1918] (2, B. M.).

Siboga station 122; east of northern Celebes (lat, 1°58'30" N.,long. 125°00'30" E.);
1,165-1,264 meters; stone; July 17, 1899 [A. H. Clark, 1918] (4, U.S.N.M., E. 3216;
Amsterdam Mus.).

Menado Bay, northern Celebes (lat. 1°31'N., long. 124°47' E.) ; 457 meters;
Captain Christiansen, Great Northern Telegraph Company, March 12, 1913 (3, C. M.).

Geographical range. — From Mindanao to northern Celebes.

Bathymetrical range.- — From 457 to 1,165 (?1,264) meters;

Thermal range. —From 5.1° to 5.44° C.

History. — Antedon valida was described and figured by Dr. P. H. Carpenter in
his report on the comatulids of the Challenger expedition published in 1888, his material
consisting of two mutilated individuals and one younger from station 214. Dr. Clemens
Hartlaub in 1895 discussed its systematic and bathymetrical relationships and compared
it with his new species Antedon (Thalassometra) agassizii.

In my first revision of the old genus Antedon published in 1907 I placed valida'\n
the new genus Thalassomeira , and in my revision of the family Thalassomctridae pub-
lished in 1909 I listed Antedon valida among the species I was not able to allocate satis-
factorily. Later in 1909 I described Crotalometra eupedata from a single specimen from
Albatross station 5236. In the original description a young individual with arms 60
mm. long possessing one IIBr 4(3 + 4) series was, listed from station 5116. In 1911 I
compared C. eupedata with the new species C. propinqua. I said that in C. eupedata
the second and following brachials are thickly covered with minute 'spines, but they
are evenly distributed over the entire surface, lateral as well as dorsal, and they are
neither so large nor so long as in C. propinqua. In the same paper I determined as
Thalassometra (Oceanometra) annandalei the small specimen from Albatross station
5116 originally identified as C. eupedata. In my memoir on the crinoids of the Indian

114 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Ocean published in 1912 Crotalometra eupedata and C. valida were listed, and the syn-
onymy and range of each were given. In a paper on the crinoids of the British Museum
published in 1913 notes were given on two specimens of Aglaometra lalida from Chal-
lenger station 214, and this form was compared with A. eupedata. In my memoir on the
unstalked crinoids of the Siboga expedition published in 1918 valida and eupedata were
included in a key to the species of Aglaometra, and the synonymy and range of each
was given.

AGtAOMETRA INCERTA (P. H. Carpenter)

[See vol. 1, pt. 2, pi. 14, fig. 1062, pi. 27, fig. 1166.]

Antedon incerta P. H. CARPENTER, Challenger Reports, Zoology, vol. 11, part 32, 1884, pp. 57, 83
(occurrence of ambulacral grooves on the genital pinnules), pi. 54, figs. 6, 7; vol. 26, part 60,
1888, p. 106 (description; Challenger station 170A), pi. 18, fig. 4, 5. — BATESON, Materials for the
study of variation, 1894, p. 421 (abnormal specimen). — HARTLAUB, Bull. Mus. Comp. Zool.,
vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrical relationships). — HUTTON, Index
faunae Novae Zealandiae, 1904, p. 290 (listed). — HAMANN, Bronn's Klassen und Ordnungen des
Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Proc. Biol. Soc. Washington,
vol. 22, 1909, p. 18 (not placed in a revision of the Thalassometridae) ; Proc. U. S. Nat. Mus.,
vol. 36, 1909, p. 404 (referred to Crotalometra) ; Crinoids of the Indian Ocean, 1912, p. 33 (of
P. H. Carpenter, 1888= Crotalometra incerta).

Thalassometra incerta A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Crotalometra incerta A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 33 ( = Antedon incerta P. H.
Carpenter, 1888), p. 209 (synonymy).

Aglaometra incerta A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47 (published
references to specimens in the B. M.; Challenger station 170A; character of the IBr series);
Unstalked crinoids of the 5z6o</a-Exped., 1918, p. 163 (in key; range), p. 165 (references). —
GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7, No. 29 (Challenger station 170a; notes;
perhaps a Thalassometra).

Diagnostic features. — The elements of the IBr series and lower brachials are in
close lateral contact; the proximal portion of the animal is broadly rounded, the pro-
files of the axillaries making with each other an angle of approximately 90°, but the
arm bases being nearly parallel; and the cirri are long and stout, somewhat more than
half as long as the arms. The 10 arms are 90 mm. long, and the cirri are 50 mm.
long with 70 segments.

Description. — The centrodorsal is bluntly conical with the interradial angles at the
base slightly produced. The cirrus sockets are arranged in 10 columns, two to a
column, the two columns in each radial area being apparently either in apposition or
more or less separated in the midradial line.

The cirri are about XX, nearly 70, sometimes reaching 50 mm. in length. The
ninth-twelfth segments are longer than broad, and those following gradually shorten
and develop a dorsal keel which is most marked in the middle third.

The radials are barely visible. The elements of the IBr series are somewhat
sharply carinate. The IBr2 (axillaries) and first brachials have sharp edges and
flattened sides. The second brachials and the hypozygals of the first syzygial pairs
are flattened on the inner side only. The articular line between the first two brachials
is somewhat tubercular.

The 10 arms are probably about 90 mm. long and are composed of tolerably smooth
subtriangular brachials which gradually become quadrate.

A MONOGRAPH OF THE EXISTING CRENOIDS 115

Syzygies occur between brachials 3 + 4, again from between brachials 16+17 to
between brachials 21+22, and distally at intervals of from 8 to 16 muscular articu-
lations.

The lower pinnules are stout with broad carinate segments; they diminish in
size from the second to the seventh brachial and then increase slowly. The later
pinnules are styliform with the two basal segments slightly expanded. The basal
segments of PI have then* outer sides somewhat flattened, and the third-fifth have their
inner edges truncated so as to be flattened against the arm.

The disk is about 10 mm. in diameter and is thickly covered with plates which
extend out on to the arms at the sides of the ambulacra and also over the gonads.
The pinnules have well-defined side- and covering-plates, most of the former being
notched for the presence of sacculi which are small, but pretty regularly distributed.

The color in alcohol is dirty yellowish white.

Notes. — Carpenter said that this is a smaller species than A. valida; the cirri,
though containing the same number of segments, do not reach more than 50 mm. in
length as compared with 80 mm. in that species. The flattening of the outer side of
the basal pinnules is not so evident, and the lower segments of the distal pinnules
show but little trace of the expanded trapezoidal form that is so characteristic of
A. valida. The sacculi, too, are much more abundant than in the latter species, the
side plates being notched for their reception. The ambulacra extend onto the genital
pinnules, as is also the case in A. valida, but the plates covering the gonads are much
less developed than in the species like Poecilometra acoela, which have no ambulacra
on these pinnules.

I examined the single specimen of A. incerta at the British Museum in 1910.
This is a large and robust species ; the edges of the ossicles of the IBr series are spinous ;
the well developed synarthrial tubercles resemble those of certain species of Psathyro-
metra.

Prof. Torsten Gisle'n examined this specimen in 1925 and published notes on it
in 1928. He said that the synarthrial tubercles are carinate and the brachials are
bordered with spines. He suggests that it is perhaps a Thalassometra.

Abnormality. — In the single known specimen one of the postradial series lacked
the IBr], the IBr2 (axillary) immediately following the radial. This axillary is smaller
and more triangular than the other axillaries so that the pair of first bracbials which
it bears are in close lateral contact with the axillaries of the postradial series on either side.

Locality. — Challenger station 170A; near the Kermadec Islands, north of New
Zealand (lat. 29°45' S., long. 178°11' W.) ; 1,152 meters; bottom temperature 4.17°
C.; volcanic mud; July 14, 1874 [P. H. Carpenter, 1884, 1888; Bateson, 1894; Hartlaub,
1895;Hutton, 1904; A. H. Clark, 1907, 1909, 1912, 1913, 1918; Gisle'n, 1928] (1, B. M.).

History. — Antedon incerta was first mentioned by Dr. P. H. Carpenter in his report
upon the stalked crinoids of the Challenger expedition published in 1884. Carpenter
gave a specific formula for the species following Bell's method as modified by himself,
and noted that in this species, although the genital pinnules are protected by a very
close and regular pavement of anambulacral plates, the ambulacra extend over these
plates in the usual way. He noted that in Antedon incerta the protecting anambucral

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

plates are smaller and more irregular than they are in Antedon (Poecilometra) acoela.
He figured a side view of a genital pinnule with its ambulacrum, and the ambulacral
skeleton of an arm and the bases of six pinnules. In his report upon the comatulids of
of the Challenger expedition published in 1888 he described and figured A. incerta
in detail.

Prof. William Bateson mentioned the abnormal postradial series of the type speci-
men in 1894, and in 1895 Dr. Clemens Hartlaub discussed the systematic and bathy-
metrical relationships of the species. Capt. Frederick Wollaston Hutton listed Antedon
incerta among the echinoderms found in the New Zealand seas in 1904.

In my first revision of the genus Antedon published in 1907 incerta was assigned to
the new genus Thalassometra. In my revision of the family Thalassometridae published
in 1909 Antedon incerta was listed among the species I was unable to place satisfactorily.
In another paper published later in the same year incerta was referred to the new genus
Crotalometra. In my memoir on the crinoids of the Indian Ocean published in 1912
Crotalometra incerta was listed and the range and synonymy were given, and in a paper
on the crinoids of the British Museum published in 1913 I gave brief notes on the type
specimen of Aglaometra incerta, which I had examined in 1910. In my memoir on the
uns talked crinoids of the Siboga expedition published in 1918 incerta was included in the
key to the species of Aglaometra, and the synonymy and range were given.

In 1928, Prof. Torsten Gislen, who had examined the type specimen in 1925,
published brief notes on Aglaometra incerta and suggested that perhaps it is a species of
Thalassometra.

AGLAOMETRA PROPINQUA (A. H. Clark)

PLATE 15, FIGURE 47

Crotalometra propinqua A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 549 (description; Albatross
station 5424; also stations 5274, 5445); Zool. Anz., vol. 39, No. 11/12, 1912, p. 427 (compared
with C. sulcata); Crinoids of the Indian Ocean, 1912, p. 209 (synonymy; locality).

Crotalometra vera A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 427 (description; Siboga station
173).

Aglaometra vera A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 163 (in key; range),
p. 165 (description; station 173), p. 274 (listed), pi. 21, fig. 54.

Aglaometra propinqua A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 163 (in key;
range), p. 165 (references).

Diagnostic features. — The cirri are rather slender, less than half the arm length;
the division series and lower brachials are in close lateral contact; and the proximal
portion of the animal is broadly rounded. The 10 arms are 130 mm. long, and the cirri
are 45-60 mm. long with 59-69 segments.

Description. — The centrodorsal is moderate in size, conical, the sides slightly con-
vex, 5.5 mm. broad at the base a.nd 4.5 mm. high to 4.5 mm. broad at the base and 3.5
mm. high, the tip somewhat truncated. The cirrus sockets are arranged in 10 columns,
two or three to a column; the columns are slightly separated in the midradial line and in
close apposition interradially.

The cirri are XX, 59-64, from 45 to 55 mm. long, moderately stout, though not
nearly so stout as those of A. eupedata; the first three segments are short, the fourth or
fifth as long as broad; the fifth, sixth, or seventh (usually the sixth) is a transition seg-
ment, half again as long as broad. The following segments gradually decrease in length,
becoming about as long as broad on the fourteenth-sixteenth, and distally twice as

A MONOGRAPH OF THE EXISTING CRINOIDS 117

broad as long. Shortly after the transition segment the distal dorsal edge of the seg-
ments begins to become produced, rising up to form a sort of gable, which leans some-
what inward, with serrate sides and a blunt tubercle at the apex, but the dorsal surface
of the segments does not become generally carinate as is usually the case.

The ends of the basal rays are visible as prominent, though small, tubercles in the
angles of the calyx.

The radials are just visible beyond the edge of the centrodorsal ; they are more
or less covered with fine spines and have a finely serrate distal border. The IBrj
are very short, about four times as broad as long, convex proximally, concave distally.
The IBr2 (axillaries) are rhombic with the sides concave, twice as broad as long, the
lateral edges shorter than those of the IBri. The elements of the IBr series and first
two brachials have somewhat everted and finely spinous edges, sometimes also scattered
fine spines on the dorsal surface and a thick development of fine spines along the lateral
margins, which are somewhat produced.

The 10 arms are 130 mm. long. The first brachials are short, twice as broad as long
exteriorly, somewhat incised on the distal margin. The broadly rounded synarthrial
tubercles are moderately prominent. The second brachials are larger with a rounded
posterior process incising the first. The first syzygial pair (composed of brachials 3 + 4)
is from one-third to one-half again as broad as long and oblong. The next four brachials
are oblong, about two and one-half times as broad as long, those following becoming
obliquely wedge-shaped and then triangular, as long as broad, and wedge-shaped
again distally. The earlier brachials have everted and finely spinous distal ends.
The fourth and following brachials have the dorsal, but not the lateral, surface thickly
covered with fine spines which on the outer brachials become somewhat coarser and
are directed distally. Proximally as the brachials become wedge-shaped the distal
edge begins to overlap and the proximal edge to lose its eversion so that the later
brachials acquire strongly produced and very spinous distal ends.

Notes. — In the original description I said that in A. eupedata (=valida) the second
and following brachials are thickly covered with minute spines, but these are evenly
distributed over the entire exposed surface, lateral as well as dorsal, and they are
neither so large nor so long as in this species.

The specimen from Albatross station 5274 is somewhat larger than the others,
with the arms about 150 mm. in length.

Crotalometra vera was briefly described as follows:

The cirri have 62-69 segments and are 60 mm. long. The longest cirrus segments
are from one-third to one-half again as long as broad; the sixth or seventh is a transition
segment.

The edges of the ossicles of the IBr series and of the earlier brachials are only
very slightly, if at all, everted and are either armed with exceedingly fine spines or
quite smooth. The spines within the distal angle of the axillaries and on the dorsal
surface of the ossicles are exceedingly short and fine and difficult to detect.

The 10 arms are about 130 mm. long.

Except for the features noted this species agrees with A. propinqua.

Localities. — Albatross station 5274; China Sea in the vicinity of southern Luzon;
Malavatuan Island (N.) bearing S. 73°30' E., 17.5 miles distant (lat. 13°57'30" N.,

118 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

long. 120°03'25" E.); 960 meters; bottom temperature 5.2° C.; gray mud and sand;
July 16, 1908 [A. H. Clark, 1911, 1912, 1918] (1, U.S.N.M., 35579).

Albatross station 5445; off the east coast of Luzon • Atalaya Point, Batag Island,
bearing S. 56° E., 5.3 miles distant (lat. 12°44'42" N., long. 124°59'50" E.); 700
meters; bottom temperature 6.8° C.; green mud and sand; June 3, 1909 [A. H. Clark,
1911, 1912, 1918] (1, U.S.N.M., 35581).

Albatross station 5424; Jol6 (Sulu) Sea; Cagayan Island (S.) bearing S. 11° W.,
3.4 miles distant (lat. 9°37'05" N., long. 121°12'37" E.); 622 meters; bottom tempera-
ture 10.2° C.; coral sand; March 31, 1909 [A. H. Clark, 1911, 1912, 1918] (2, U.S.N.M.,
27498, 35578).

Siboga station 173; Ceram Sea (lat. 3°27'00" S., long. 131°00'30" E.); 567 meters;
fine yellow gray mud; August 28, 1899 [A. H. Clark, 1912, 1918] (2, U.S.N.M., E. 397;
Amsterdam Mus.).

Geographical range. — From the northern Philippines to the southern Moluccas.

Bathymetrical range. — From 567 to 960 meters.

Thermal range.— From 5.2° to 10.2° C.

History. — Crotalometra propinqua was described in 1911 from two specimens from
Albatross station 5424; at the same time one specimen was recorded from station 5274,
and one from station 5445. In a paper including preliminary descriptions of new species
collected by the Siboga expedition published in 1912 Crotalometra propinqua was com-
pared with C. sulcata, sp. nov., and Crotalometra vera, sp. nov., was described from two
specimens from Siboga station 173. In my memoir on the crinoids of the Indian Ocean
published later in 1912 I listed Crotalometra propinqua, giving the synonymy and
range. In my memoir on the unstalked crinoids of the Siboga expedition published in
1918 propinqua and vera were included in a key to the species of Aglaometra; A. vera
was redescribed and figured, and the synonymy and range of A. propinqua were given.

AGLAOMETRA SULCATA (A. H. Clark)

PLATE 13, FIGURE 40

Crotalometra sulcata A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 427 (description; Siboga

station 161).
Aglaometra sulcata A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 163 (in key;

range), p. 164 (description; station 161), p. 273 (listed), pi. 21, fig. 53.

Diagnostic features. — The distal angles of the IBri and proximal angles of the
axillaries, and the corresponding angles of the first two brachials and of the elements of
the first syzygial pairs, are widely cut away, forming large and prominent water pores;
and the cirri are moderately slender, slightly more than half the length of the arms.
The 10 arms are about 115 mm. long, and the cirri are 60-65 mm. long with 63-64
segments.

Description. — The centrodorsal is columnar in the proximal half, rather low conical
in the distal, with the cirrus sockets arranged in 10 columns of usually one fully and
one partially developed one each; the two columns in each radial area are more or less
separated in the midradial line.

The cirri are X, 63-64, from 60 to 65 mm. long. The eighth-fourteenth segments
are about twice as long as broad; those in the distal third of the cirri are about half
again as broad as long with prominent dorsal spines.

A MONOGRAPH OF THE EXISTING CRINOIDS 119

The ossicles of the IBr series and lower brachials are almost smooth. The distal
angles of the IBri and the proximal angles of the IBr2 (axillaries) , and the corresponding
angles of the first two brachials and of the elements of the first syzygial pair, are widely
cut away forming large and prominent water pores. The edges of the ossicles bordering
these water pores are more or less everted and coarsely denticulate, or bear a few
coarse spines.

The 10 arms are about 115 mm. long. The dorsal surface of the brachials beyond
the first syzygial pair is roughened with numerous short crowded spines.

Syzygies occur between brachials 3+4, again from between brachials 14+15 to
between brachials 16+17, and distally at intervals of from 4 to 8 muscular articulations.

Notes. — In the specimen from Menado Bay, Celebes, one IIBr 2 series is present
so that there are 1 1 arms.

Localities. — Siboga station 161; Halmahera Sea, west of Waigeu (lat. 1°10'30" S.,
long. 130°09'00" E.); 798 meters; muddy sand; August 17, 1899 [A. H. Clark, 1912,
1918] (1, Amsterdam Mus.).

Menado Bay, northern Celebes (lat. 1°31' N., long. 124° 47' E.); 457 meters;
Captain Christiansen, Great Northern Telegraph Company, March 12, 1913 (1, C. M.).

Geographical range. — From the Halmahera Sea west of Waigeu northward to Me-
nado Bay, Celebes.

Bathymetrwal range. — From 457 to 798 meters.

History. — This species was described in 1912 under the name of Crotalometra
sulcata. It was redescribed and figured as Aglaometra sulcata in 1918.

Genus STIREMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Proc. Roy. Soc. Edinburgh, vol. 12, 1884, p. 368, and following
authors.

Thalassomelra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 359.

Stiremetra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (diagnosis; genotype Antedon
acutiradia P. H. Carpenter, 1888); Mem. Australian Mus., vol. 4, 1911, pp. 730, 731 (in key),
p. 735 (one species in Australia), p. 789 (original reference; characters; range); Crinoids of the
Indian Ocean, 1912, p. 10 (absent from Japan), p. 11 (absent from the west coast of the Malay
Peninsula, the Andamans, and from farther west), p. 24 (range), p. 59 (in key), p. 210 (original
reference; type); Die Crinoiden der Antarktis, 1915, p. 125 (the component species show the
characteristic features of Anlhometra adriani}', Unstalked crinoids of the Siboga-Kxped., 1918,
p. 146 (in key; range), p. 160 (key to the included species); The Danish Ingolf-Exped., vol. 4,
No. 5, Crinoidea, 1923, p. 40 (range). — GISLEN, Vid. Medd. Dansk naturh. Foren. K0benhavn,
vol. 83, 1927, p. 6. — MORTENSEN, Handbook of the echinoderms of the British Isles, 1927, p. 25
(occurrence in northeast Atlantic; in key). — NOBRE, Echinodermes de Portugal, 1931, p. 163
(diagnosis). — GISL&N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 18. —
NOBRE, Echinodermes de Portugal, 1938, p. 185 (in key), p. 186.

Diagnosis. — A genus of Thalassometridae in which the arms are dorsally rounded
to the tips and are 10-14 (rarely more than 10) in number, with the IIBr series 2 or
4(3+4); the division series and arm bases are carihate or subcarinate, smooth dorsally
and with straight sides or sometimes everted edges; the cirri are recurved distally, the
short outer segments bearing prominent dorsal spines; there is no appreciable expansion
of the earlier segments of the genital pinnules; and the size is small, the arms being
45-80 mm. in length and the cirri 17-50 mm. long with 30-66 segments.

120 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Geographical range. — Hawaiian Islands; Celebes; Fiji; Kermadec Islands; off
southeastern Australia; Laccadive Islands; Canary Islands and northward to Cape
Carvoeiro, Portugal.

Bathymetrical range. — From 649 (?640) to 2,468 meters.

Thermal range.— From 2.2° to 9.6° C.

Remarks. — The genus Stiremetra should be considered as a tentative grouping of a
rather heterogeneous assemblage of forms most of which are known from one or a few
mutilated individuals.

The included species are all small and delicate, and all are from deep water. Most
of the individuals are badly broken in the long journey in the dredge from the bottom
to the surface intermixed with other stouter and tougher organisms, and few are re-
covered in a condition permitting satisfactory description.

Stiremetra lusitanica is a rather anomalous species, though there seems to be no
good reason for not considering it congeneric with at least some of the other species
included in Stiremetra. It is the only species having more than 10 arms, the IIBr
series being either 2 or 4(3+4); but the majority of the individuals appear to have 10
arms only. Its centrodorsal is large with the cirri arranged roughly in 15 columns
instead of in 10 definite columns, and it is the only species of the genus known from the
Atlantic.

Another anomalous species is S. breviradia in which the brachials bear long over-
lapping spines which at first sight suggest those of Stylometra spinifera. But the resem-
blance is undoubtedly superficial, for in its other characters S. breviradia agrees with
the species grouped in Stiremetra.

It is possible that the two species in which the axillaries are shield-shaped and
longer than broad, S. acutiradia and S. perplexa, represent a special group, but both are
incompletely known, and in general the length of the axillaries is a variable feature much
influenced by growth changes.

Stiremetra spinicirra is remarkable for the great development of the cirrus spines,
and S. decora is the only species with highly developed ornamentation; it is also the
species recorded from the least depth. Stiremetra carinifera is known from such
fragmentary material that little can be said about it; it is, however, the only repre-
sentative of the genus known from the Indian Ocean.

KEY TO THE SPECIES IN THE GENUS STIREMETRA

a1. Cirri with 50-66 segments, six or more of the basal without dorsal spines; IBr series and lower

brachials with a rounded median ridge; large, the arms up to 80 mm. long.

fci. Cirri more or less irregularly arranged on the centrodorsal, roughly in 15 columns; 10-14 (usually
10) arms about 60 mm. long; cirri nearly 30 mm. long with 50-56 segments (Canary Islands

to Cape Carvoeiro, Portugal; 1,280 [?914]-2,165 meters) lusitanica (p. 121)

b1. Cirri arranged in 10 columns on the centrodorsal; always 10 arma

c>. Brachials beyond the proximal fourth of the arms with the dorsal midline raised and pro-
duced distally over the base of the brachials succeeding forming, in lateral view, high and
conspicuous curved overlapping spines; IBr series and first two brachials smooth dorsally,
with straight sides, the carination low and broad or obsolescent; arms about 80 mm. long;
cirri with 40-50+ segments (Fiji to the Kermadec Islands; 1,152-2,285 meters).

breviradia (p. 126)
c2. Brachials with the dorsal surface not raised into prominent dorsal overlapping spines.

(P. Axillaries shield-shaped, very long, half again as long as broad, smooth, very sharply
flattened laterally, the edges unmodified; IBri with the central portion of the dorsal

A MONOGRAPH OF THE EXISTING CRINOIDS 121

surface recumbent, making an angle of approximately 90° with the dorsoventral axis,
the edges smooth and unmodified; cirri 35-40 mm. long with 62-66 segments (off Celebes;

1,158 meters) perplexa (p. 129)

d1. IBr, with the proximal and distal edges prominently everted, smooth, somewhat wavy, or
coarsely tubercular, and with a prominent median rounded carination; cirri 45-50 mm.
long with 50-64 (usually 57-58) segments (Laccadive Sea; 786 meters) .carinif era (p. 130)
a*. Cirri with not more than 45 segments of which all but the basal four or less bear long and con-
spicuous dorsal spines; elements of the IBr series and first two brachials sharply carinate;
small and delicate, the 10 arms not more than 50 mm. long.
61. The first four cirrus segments do not bear dorsal spines; the fourth and a few of the following

segments are nearly or quite twice as long as broad; arms about 50 mm. long.
cl. Axillaries longer than broad; IBr series and lower brachials with straight sharp edges, a sharp
median carination, and a smooth dorsal surface (off Kandavu, Fiji; 2,468 meters).

acutiradia (p. 132)

c2. Axillaries nearly or quite twice as broad as long; IBri with two long and rather stout blunt

spines, one on the distal and one near the proximal edge, and a similar but shorter spine

on each side; axillaries with a high median crest that may be more or less deeply notched

in the middle; 30-40 cirrus segments (Hawaiian Islands; 640-649 meters) .decora (p. 134)

V. All, or all but one or two, of the cirrus segments bear high, broad, and conspicuous dorsal spines;

a few of the earlier cirrus segments are slightly longer than broad; arms about 45 mm. long;

cirri 17 mm. long with 40-45 segments (off Sydney, New South Wales; 1,737 meters).

spinicirra (p. 136)

STIREMETRA LUSITANICA (P. H. Carpenter)

Comatules PABFAIT, Rapport sur la campagne scientifique du Talisman en 1883, 1884, p. 43 (lat.
33°47' N., long. 11°23' W.; 1,635 meters; "comatules jaune soufre")- — A. H. CLARK, Proc.
U. S. Nat. Mus., vol. 40, 1911, p. 48.

Antedon lusitanica P. H. CARPENTER, Proc. Roy. Soc. Edinburgh, vol. 12, 1884, p. 368 (detailed
description; Porcupine, 1870, station 17a; discussion), p. 372 (Porcupine, 1870, station 17o);
Challenger Reports, Zoology, vol. 11, pt. 32, 1884, p. 315 (Porcupine station 17a, with fragments
of Pentacrinus [Annacrinus] wyville-thomsoni) ; vol. 26, pt. 60, 1888, pp. 109, 217 (description;
Porcupine station 17o; discussion), pi. 39, figs. 1-3; Journ. Linn. Soc. (Zool.), vol. 24, 1891,
p. 65 (neighborhood of Madeira, from a submarine cable in 500-700 fathoms; discussion). —
HARTLATJB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (in the Basicurva group; bathy-
metrical relationships), p. 135 (compared with [Thalassometra] agassizii, sp. nov.). — GRIEG,
Bergens Mus. Aarbog for 1903 (=1904), No. 5, 1904, p. 35.— MINCKERT, Arch. Naturg., Jahrg.
71, 1905, vol. 1, Heft 1, p. 211 (syzygies; regeneration). — HAMANN, Bronn's Klassen und Ordnun-
gen des Tier-Reichs, vol. 2, Abt. 3, 1907, pp. 1578, 1581 (listed). — KOEHLER, Re"sultats des
campagnes scientifiques accomplies sur son yacht par Albert 1" Prince souverain de Monaco,
fasc. 34, 1909, p. 267 (Princesse- Alice stations 806, 1897; 1116, 1236, 1901; 1713, 1904; 2048, 1906),
pi. 1, figs. 7, 8, pi. 32, figs. 12-14. — A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p.
18 (not allocated in the revision of the Thalassometridae). — -HARTLAUB, Mem. Mus. Comp. Zool.,
vol. 27, No. 4, 1912, p. 309 (in the Spinifera group; history) .— MORTENSEN, Handbook of the
echinoderms of the British Isles, 1927, p. 25.

Thalassometra lusitanica A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Proc. U. S. Nat. Mus., vol. 40, 1911, p. 7 (northwestern coast of Africa), p. 37 (synonymy;
Madeira; south of Funchal; off the southeastern coast of Tenerife; near Mogador; between
Madeira and Morocco; 900-2,165 meters); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p.
46 (published references to specimens in the British Museum; Porcupine station 17a, 1870);
Unstalked crinoids of the Siboga Exped., 1918, p. 167 (in key; range), p. 171 (references). — NOBRE,
Echinodermes de Portugal, 1931, p. 163.

Antedon (Crotalometra) lusitanica KOEHLER and VANET, Bull. Mus. d'Hist. Nat. Paris, 1910, No. 1,
p. 26 (collected by the Travailleur or Talisman), p. 31 (lat. 33°17' N., long. 11°23' W.; 1,635
meters) .

843803—50 9

122 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Stiremetra lusitanica A. H. CLARK, The Danish 7nffo//-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40
(range). — NOBRE, Echinodermes de Portugal, 1931, p. 163 (records). — MORTENSEN, Handbook
of the echinoderrns of the British Isles, 1927, p. 25 (localities). — NOBRE, Echinodermes de
Portugal, 1938, p. 186 (description; notes).

Diagnostic features. — The cirri are irregularly arranged on the centrodorsal,
roughly in 15 columns; the division series and arm bases are perfectly smooth dorsally
with sharp, straight, unmodified lateral edges and the middorsal region roundedly
carinate; the 10-14 (usually 10) arms, with the IIBr series either 2 or 4(3+4), are
about 60 mm. long, and the cirri, which are rather stout, are nearly 30 mm. long with
50-56 segments.

Description. — The centrodorsal is hemispherical, roughened at the dorsal pole.

The cirri are XII-XV, about 50, nearly 30 mm. long. The first three or four seg-
ments are quite short, the three following much longer, and those succeeding longer
than broad but becoming gradually shorter up to the fifteenth or twentieth; from this
point (or earlier) to the end of the cirri the segments have a well marked dorsal spine
which becomes slightly less distinct on those just preceding the terminal claw.

The radials are scarcely visible except sometimes in the interradial angles. The
IBri are short and trapezoidal with a strong median ridge which is continued on to the
axillaries. The IBr2 (axillaries) are short, broad, and pentagonal with slight backward
projections in the middle of the proximal border. The axillaries and first two brachials
have sharp straight edges and flattened sides. The IIBr series (when present) are 2.

The 10-12 (usually 10) arms are about 60 mm. long, with smooth elongate brachials.
The first brachials are not much incised, and the outer portions of their dorsal surface
are usuaUy much less convex than the remainder. The second brachials project more or
less proximally into the first. They and the first syzygial pairs (composed of brachials
3+4) are somewhat flattened on the inner side. The three following brachials are
squarish, those following more elongated with very oblique ends.

Syzygies occur between brachials 3+4 and 15+16 or 16+17.

PI is moderately long with about 15 broad segments. The lower segments are
stout and wide with the outer sides somewhat flattened; the second and three or four
following segments have their inner edges produced into strong and prominent keels
which are slightly folded upward; these keels are continued, though less developed,
on to the later segments. The pinnules following are altogether smaller, consisting of
but a few slender segments.

The disk is 5 mm. in diameter and is thickly covered with numerous small plates,
those at the sides of the ambulacra being rather more regularly arranged than the rest.
The pinnule ambulacra are not well defined, but the sacculi are moderately developed.

The color in alcohol is brownish or greenish white.

Notes.- — -The preceding description is adapted from Carpenter's original description
published in 1884, supplemented with additional information from his redescription
published in 1888.

According to Koehler all the specimens from Princesse-Alice stations 1236 and 1713
had 10 arms. Of the three specimens from Princesse-Alice station 2048 two had 10 arms
and one had 11. Of the specimens from Princesse-Alice station 806 nine had 10 arms;
in four all the arms were broken off at the first syzygy; three had more than 10 arms,
one having 11, one 12, and one 13.

A MONOGRAPH OF THE EXISTING CRINOIDS

123

Koehler said that the specimens collected by the Princesse-Alice were in general
incomplete, and in many of them the arms were broken off at the first syzygy so that
the number of arms may have been greater than that given. He noted that Carpenter,
who had carefully studied this species, directed attention to the variability in the
number of arms. The normal number appears to be 10, though it may be more, in
which case the IIBr series are 2, or sometimes 4(3 + 4). He remarked that Carpenter
cited the case of an individual collected by the Challenger (in reality the Porcupine)
with two IIBr 2 series and at least 12 arms, and in a paper published in 1891 Carpenter
recorded an individual with at least 14 arms and with both IIBr 2 and IIBr 4(3+4)
series.

Koehler said that the first syzygy is between brachials 3 + 4 and the second usually
between brachials 13+14; those following occur at intervals of 4 or 5 muscular artic-
ulations.

Carpenter said that Mr. Johnson's specimens from near Madeira are larger than
those obtained by the Porcupine, one of the cirri having 56 segments. One individual
may have had only 10 arms. A second had 11 and perhaps more, but most of them are
broken at the base, only one IIBr 2 series being left. The third had 14 or more arms,
there being one IIBr 2 series and three IIBr 4(3+4) series remaining; of the six arms
following the three IIBr 4(3+4) series three have the first syzygy between brachials
1+2, and in the other three there is a syzygy between brachials 2 + 3.

Nearly all the 10 specimens dredged by the Porcupine had the arms broken off at
the first syzygy, and Carpenter said it was therefore quite possible that the epizygal
of this syzygial pair might sometimes have been a IIBr axillary. He noted that in one
specimen there are two IIBr 2 series.

Localities. — Princesse-Alice station 1713; off Tenerife, Canary Islands (lat. 28°04'
N., long. 16°49'30" W.); 1,330-1,340 meters; August 1, 1904 [Koehler, 1909; A. H.
Clark, 1911, 1923; Mortensen, 1927].

Princesse-Alice station 1116; off Cape Ghir (Ras Aferni), Morocco (lat. 31°43'30"
N., long. 10°46'45" W.); 2,165 meters; globigerina ooze; July 11, 1901 [Koehler, 1909;
A. H. Clark, 1911, 1923; Mortensen, 1927].

Princesse-Alice station 2048; off Funchal, Madeira (lat. 32°32'30" N., long. 17°02'
W.); 1,968 meters; July 31, 1905 [Koehler, 1909; A.H.Clark, 1911, 1923; Mortensen,
1927].

Princesse-Alice station 1236; off Funchal, Madeira (lat. 32°34' N., long. 17°02'45"
W.); 1,500 meters; September 8, 1901 [Koehler, 1909; A. H. Clark, 1911, 1923; Mor-
tensen, 1927].

Princesse-Alice station 806; off Machico, Madeira (lat. 32°39'20" N.,long. 16°40'55"
W.); 1,425 meters; July 4, 1897 [Koehler, 1909; A. H. Clark, 1911, 1923; Mortensen,
1927].

In the neighborhood of Madeira, from a submarine cable belonging to the Brazilian
Submarine Telegraph Co.; 914-1,280 meters; J. Y. Johnson [P. H. Carpenter, 1891;
Hartlaub, 1895; Koehler, 1909 (as "cdtes du Brazil"); A. H. Clark, 1911, 1923;
Mortensen, 1927].

Talisman; west of Cape Blanco, Morocco (lat. 33°17' N., long. 11°23' W.); 1,635
meters; June 14, 1883 [Parfait, 1884; Koehler and Vaney, 1910; A. H. Clark, 1911,
1923; Mortensen, 1927].

124 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Porcupine station 17a; off Cape Carvoeiro, Portugal (lat. 39°39' N., long. 9°39'
W.); 1,353 meters; bottom temperature 9.6° C.; 1870 [P. H. Carpenter, 1884, 1888,
1891; Hartlaub, 1895; Grieg, 1904; A. H. Clark, 1913, 1923; Mortensen, 1927] (3,
B. M.).

Geographical range. — From the Canary Islands northward to Cape Carvoeiro,
Portugal.

Bathymetrical range. — From 1,280 (?914)-2,165 meters; the average of 8 records
is 1,491 meters.

Thermal range. — One record, 9.6° C.

History. — This species was described as Antedon lusitanica by Dr. P. H. Carpenter
in 1884 from 10 mutilated specimens that had been dredged by the Porcupine in 1870.
Carpenter said that this species seems to be dimorphic, like Actinometra (Neocomatella)
pulchella, and to constitute another exception to the general rule that 10-armed types
are sharply separated from those in which the primary arms divide. He remarked that
the length and spiny character of its cirri, and the peculiarities of its pinnules, readily
distinguish it from all the species of Antedon hitherto described. But, he said, it has
many points of resemblance to some of those dredged by the Blake in the Caribbean
Sea. It is a type of some interest for two reasons. It is the only European comatulid
which is in the condition of the so-called recent cystid, Hyponome sarsii (—Zygometra
microdiscus) , with a plated disk and the ambulacra converted into tunnels by the folding
down of the plates at then1 sides; and it is the only European Antedon with more than
10 arms.

In 1884 also Capt. Jacques Theophile Parfait in a report on the scientific investiga-
tions of the French steamer Talisman, of which he was the commanding officer, in
1883 mentioned some "comatules jaune soufre" from lat. 33°47' [=17'] N., long.
11°23' W., in 1,635 meters.

In the Challenger report on the stalked crinoids published in 1884 Carpenter said
that a few fragments of stems and arms of Pentacrinus (Annacrinus) wyville-thomsoni
had been dredged with the ten specimens of Antedon lusitanica from Porcupine station
17a. In the Challenger report on the comatulids published in 1888 Carpenter rede-
scribed and figured Antedon lusitanica and discussed the occurrence of two IIBr 2
series in one of the ten specimens at length. He remarked that sacculi are present
and fairly well developed. He said that the nearest ally of lusitanica is undoubtedly
Antedon (Stiremetra) breviradia from the South Pacific. He noted that both species
have the ossicles of the IBr series short and broad, this being especially the case in
lusitanica, while in most examples of lusitanica the margin of the axillaries and first
brachials is much less rounded than the rest of the dorsal surface and seems to stand
off from it as a lateral process, a character which is scarcely perceptible in breviradia.
He said that PI is also different. The keels on the inner edges of the lower segments in
lusitanica are less prominent than in breviradia, but at the same time they are more
distinctly separated from each other, and the earlier cirrus segments are relatively
longer.

In 1891 Carpenter recorded three specimens of Antedon lusitanica that had been
brought up on a cable belonging to the Brazilian Submarine Cable Co. from a depth of
500-700 fathoms in the neighborhood of Madeira and sent to him by J. Y. Johnson, of
Funchal. With these was found Annacrinus wyville-thomsoni, as had been the case

A MONOGRAPH OF THE EXISTING CRINOIDS 125

at the original Porcupine station. Carpenter thought it very probable that the com-
atulids obtained by the Talisman in depths of about 1,200 meters off the Azores and
Canaries, in 2,200 meters off Agadir, and hi 2,330 meters near the Cape Verde Islands
may belong to the same deep sea type. He said that the former, however, might possibly
also include Antedon (Leptometra) phalangium "which is now known to extend down
to at least 500 fathoms." Carpenter called attention to the similarity in the arm divi-
sion between Antedon (Stiremetra) lusitanica and A. (Thalassometra) multispina and
said that should IIBr 4(3 + 4) series prove to be common in these two species it may
become necessary to unite them under one name. At present, he said, the main points
of difference between them, apart from the characters of the arm divisions, appear to
lie in the longer cirri and less spinous arms of lusitaniea, in which also the segments of
the genital pinnules, as the Madeira specimens show, are somewhat produced upward
on the outer side as is so markedly the case in Antedon (Charitometra) basicurva; but,
he said, there is nothing of this kind in multispina.

In a survey of the Basicurva group published in 1895 Dr. Clemens Hartlaub listed
Antedon lusitanica, giving the locality and depth, and in 1904 Dr. James A. Grieg also
mentioned it as a member of the Basicurva group. Dr. Wilhlem Minckert in 1905
listed it as one of the species of the Basicurva group falling also in the Spinifera and
Granulifera groups.

In my first revision of the genus Antedon published in 1907 lusitanica was trans-
ferred to the new genus Thalassometra. In my revision of the family Thalassometridae
published in 1909 Antedon lusitanica was listed among the species I was unable to place
satisfactorily.

In 1909 Prof. Rene Koehler recorded numerous specimens of Antedon lusitanica
from the dredgings of Prince Albert of Monaco's yacht Princesse- Alice, several from
station 806 (cruise of 1897), an isolated disk from station 1116 (1901), one from station
1236 (1901), one from station 1713 (1904), and three from station 2048 (1906). He
gave figures of two specimens showing the color hi life — bright clear yellow — a figure
of a 13-armed specimen from station 806 with the IIBr series both 2 and 4(3 + 4), a
figure of a 10-armed specimen, and a figure of a specimen with the arms broken off at
the first syzygy but with almost all the cirri intact. He said that Antedon lusitanica
had been discovered by the Challenger (in reality the Porcupine) off Cape Carvoeiro,
and was rediscovered by the Princesse-Alice in neighboring regions. He added that this
species is also found on the opposite coasts of the Atlantic, as Carpenter identified it on
a fragment of broken cable coming from the coast of Brazil. This refers to Carpenter's
record from the vicinity of Madeira.

In 1910 Profs. Rend Koehler and Clement Vaney recorded, without comment, four
specimens of Antedon (Crotalometra) lusitanica, collected by the Talisman in lat.
33°17' N., long. 11°23' W. in 1,635 meters, thus identifying the "comatules jaune soufro"
mentioned by Captain Parfait in 1884.

In a paper on the crinoids of the African coasts published hi 1911 I listed Thalas-
sometra lusitanica and gave the synonymy and the localities from which it is known.
Dr. Clemens Hartlaub in 1912 listed Antedon lusitanica as a member of the Spinifera
group. In a paper on the crinoids of the British Museum published in 1913 I noted
that I had seen three specimens of Thalassometra lusitanica from Porcupine station
17a "agreeing with the published figures." In my memoir on the unstalked crinoids

126 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

of the Siboga expedition published in 1918 lusitanica was inserted in the key to the
species of Thalassometra, and the synonymy and range were given. In my memoir
on the crinoids of the Ingolf expedition published in 1923 Stiremetra lusitanica was
included and the range was given. This information was repeated by Dr. Th. Mor-
tensen in 1927 in his work on the echinoderms of the British Isles, and by Prof. Augusto
Nobre in 1931 and 1938 in his book on the echinoderms of Portugal.

STIREMETRA BREVIRADIA (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 486, 487, p. 365; pt. 2, pi. 2, figs. 975-978, pi. 44, fig. 1301.]

Antedon radiospina VON GRAFF, Bull. Mus. Comp. Zool., vol. 11, No. 7, 1883, p. 133 (nomen nudum;
Challenger station 170; myzostomes) ; Challenger Reports, Zoology, vol. 10, pt. 27, 1884, pp. 17,
19 (same); Challenger Reports, Narrative, vol. 1, pt. 1, 1885, p. 316 (same). — P. H. CARPENTER,
Challenger Reports, Zoology, vol. 26, pt. 60, 1888, pi. 3, fig. 4, o-c.— A. H. CLARK, Proc. U. S.
Nat. Mus., vol. 34, 1908, p. 491 (listed).

Antedon eversa P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, pi. 3, fig. 5, a-c. —
A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 471 (listed).

Antedon breviradia P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 110 (descrip-
tion; Challenger stations 170A, 175), pi. 3, figs. 4, a-c, 5, a-c; pi. 11, fig. 5, pi. 19, figs. 1-4, pi.
20, figs. 1, 2. — WALTHER, Einleitung in die Geol. als historisehe Wiss., 1894, p. 298 (after Car-
penter).— HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (systematic and
bathymetrical relationships). — HUTTON, Index faunae Novae Zealandiae, 1904, p. 290 (listed). —
HAMANN, Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). —
A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 33 (identity).

Thalassometra breviradia A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Stiremetra breviradia A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed); Crinoids
of the Indian Ocean, 1912, p. 33 (identity), p. 211 (synonymy; locality); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 45 (published references to specimens in the B. M.; Challenger
stations 170A, 175); Unstalked crinoids of the Siboga-Exped., 1918, p. 161 (in key; range; refer-
ences).

Antedon variospina (Brit. Mus., MS.) A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p.
45 (MS. name found with specimens from Challenger station 170A).

Diagnostic features. — The brachials beyond the proximal fourth of the arms have
long, broad, curved, overlapping spines; the IBr series and lower brachials are smooth
dorsally with straight sides, and with the median carination low and broad or obsoles-
cent; and the cirri are arranged in 10 definite columns on the centrodorsal. The 10
arms are about 80 mm. long, and the cirri have 40-50+ segments.

Description. — The centrodorsal is hemispherical or rounded truncated conical with
the dorsal pole bearing a number of papillae. The cirrus sockets are arranged in 10
columns of 2 or 3 each; the columns are in close contact interradially, but are separated
in the midradial line by a V-shaped bare area of which the base, at the rim of the cen-
trodorsal, is about as broad as the adjacent cirrus sockets and the apex lies between the
second or third cirrus sockets from the base.

The cirri are XV-XX, 40-50+ ; the seventh-tenth segments are longer than broad
and those following are shorter with a well marked dorsal spine.

The radials are scarcely visible. The IBi'i are short and convex with occasional
traces of a median ridge or keel, especially in young individuals. The IBr2 (axillaries)
are short and widely hexagonal, projecting proximally into the IBr^ they may show a
median low keel in the proximal two-thirds. The elements of the IBr series and first
brachials have straight edges and flattened sides.

A MONOGRAPH OF THE EXISTING CRINOIDS 127

The 10 arms are probably about 80 mm. long. The proximal brachials are triangular
or quadrate, rather longer than broad, and the distal are laterally compressed and over-
lapping so as to become carinate. The figures show the brachials in the outer two-
thirds of the arms with long, carinate, and curved median overlapping spines. The
inner faces of the second brachials and of the hypozygals of the first syzygial pair are
slightly flattened.

Syzygies occur between brachials 3+4, again between the thirteenth and twenty-
sixth brachials (usually about the sixteenth), and distally at intervals of from 2 to 16
(usually 4 or 5) muscular articulations.

PI, which is much larger than P2, consists of about 12 segments of which the first
sLx are wide and thick with their outer sides somewhat flattened, and the third-fifth
have their inner edges produced into expanded processes which are slightly folded up-
ward. The next 3 or 4 pinnules on either side are quite small, and the length gradually
increases, the later pinnules becoming styliform with elongated segments. On some
arms the first two segments of the distal pinnules are rather expanded and trapezoidal,
though on others they are not specially modified.

The disk is 6 mm. in diameter. The disk and the brachial ambulacra are well plated.
The side- and covering-plates along the pinnule ambulacra are generally well differen-
tiated. Sacculi are largely developed on some of the pinnules, though altogether absent
on others.

The color in alcohol is light brownish white.

Notes. — The preceding description is adapted from Carpenter with additional
information derived from his figures.

Carpenter said that in this species the IBri are relatively longer than those of S.
lusitanica and more distinctly incised by the axillaries, which are hexagonal rather
than pentagonal as in that species, while in the younger individuals both elements of
the IBr series show distinct indications of a median ridge like that which is so marked
in S. spinicirra and S. acutiradia. He said that the characters of the cirri and of PI
also separate S. breviradia from S. lusitanica, "which was probably without such dis-
tinctly carinate outer arm-joints as occur in Antedon [Stiremetra] breviradia,." He
said that some of the later pinnules have the lower segments flattened and expanded
as in Aglaometra valida, while in others there is but little trace of this peculiarity. There
is a similar variation as regards the sacculi. On some pinnules they are abundant,
alternating regularly with the side plates; on others there are very few; and some pin-
nules are altogether without them.

Carpenter remarked that the characters of the calyx undergo a considerable
amount of change during development. The centrodorsal is deeper and more conical
in the older individuals, in which the more numerous cirrus sockets are arranged in
tolerably regular columns. There are two of these columns under each interradial angle
of the calyx, each with 3 sockets which alternate with those of adjacent columns, and
the dorsal pole is covered with a number of short' stout processes of which there is but
little trace in a younger individual. The two also differ in the characters of the radial
pentagon. In the younger one its lower face is tolerably flat and smooth, with the
rosette rather near the surface and little or no indication of a basal star, while in the
older it is more deeply sunken within the axial opening and is surrounded by a fairly
definite basal star. The surface of each radial is also very convex and rises to one or

128 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

two sharp points near the middle of the distal edge. The lower part of the muscular
fossae is occupied by two or three strongly marked ridges with intervening furrows
which are altogether absent in less mature individuals. The latter, however, have the
upper end of the muscle plates more everted than in the adults, so that the central
opening of the calyx is relatively larger and more pentagonal in appearance.

Carpenter had no doubt that these were merely differences of growth, and that they
are not of specific value as he had supposed when the plates were lettered. On plate

3 of the Challenger report a young individual, the centrodorsal and radial pentagon of
which are shown in figures 5, a-c, is called eversa, and a full grown one, details of which
are shown in figures 4, a-c, is called radiospina. In the explanation to the plate figures

4 and 5 are both given under the name breviradia.

It is possible that two species are confused under the name breviradia. The
description is applicable to the form referred to by Carpenter as the older and called
on plate 3 radiospina, which therefore becomes a synonym of breviradia. If the younger
form should prove to be distinct the name eversa, occurring on plate 3, is available for it.

Localities. — Challenger station 170A; near the Kermadec Islands (lat. 29°45' S.,
long. 178°11' W.); 1,152 meters; bottom temperature 4.17° C.; volcanic mud; July 14,
1874 [von Graff, 1883, 1884, 1885; P. H. Carpenter, 1888; Walther, 1894; Hartlaub,
1895; Hutton, 1904; A. H. Clark, 1907, 1909, 1912, 1913, 1918] (3, B. M.).

Challenger station 175; near Kandavu, Fiji (lat. 19°02' S., long. 177°10' E.);
2,285 meters; bottom temperature 2.2° C.; globigerina ooze; August 12, 1874 [P. H.
Carpenter, 1888; Walther, 1894; Hartlaub, 1895; Hutton, 1904; A. H. Clark, 1907,
1909, 1912, 1913, 1918] (1, B. M.).

Geographical range. — From Fiji southward to the Kermadec Islands northeast of
New Zealand.

Bathymetrical range. — From 1,152 to 2,285 meters.

Thermal range— From 2.2° to 4.17° C.

History. — This species was first mentioned by Prof. Ludwig von Graff who in
1883 recorded and described the myzostomes found with the specimens from Challenger
station 170; in recording the host of these myzostomes Professor von Graff used the
name Antedon radiospina. He used this name again in 1884 and in 1885. When I
saw him at Graz in 1910 he told me that for the hosts of myzostomes he had accepted
the names given him by Carpenter and had left to Carpenter the task of allocating the
names in the synonymy. In the Challenger reports on the comatulids published in
1888 Carpenter gave a detailed account of this species under the name Antedon
breviradia, in the text making no mention of any other names. In the explanation of
the figures on plate 3 he listed figures 4 and 5 under Antedon breviradia, but at the bottom
of the plate the species illustrated by figure 4 is given as Antedon radiospina, and that
illustrated by figure 5 as Antedon eversa.

Walther in 1894, Hartlaub in 1895, and Hutton in 1904 mentioned Antedon
breviradia, taking their information from the Challenger report.

In my first revision of the genus Antedon published in 1907 breviradia was referred
to the new genus Thalassometra, and in 1909 I referred it to the new genus Stiremetra.
In 1912 I listed it, with the synonymy and range, in my memoir on the crinoids of the
Indian Ocean. In my paper on the crinoids of the British Museum published in 1913
I mentioned having seen four specimens from Challenger stations 175 and 170a, and

A MONOGRAPH OF THE EXISTING CRINOIDS 129

that one of the specimens from station 170a bore the manuscript name Antedon vario-
spina. In my memoir on the unstalked crinoids of the Siboga expedition published hi
1918 breviradia was inserted in a key to the species of the genus Stiremetra, and the
references and range were given.

STIREMETRA PERPLEXA (A. H. Clark)

PLATE 14, FIGURE 44

Thalassometra perpleia A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 426 (description; Siboga

station 211).
Stiremelra perplexa A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 161 (in key;

range; references; detailed description; station 211), p. 274 (listed), pi. 23, fig. 63.

Diagnostic features. — The axillaries are shield-shaped, very long, half again as
long as broad, smooth, very sharply flattened laterally, the edges unmodified; the IBr)
have the central portion of the dorsal surface recumbent, making an angle of approxi-
mately 90° with the dorsoventral axis, the edges smooth and unmodified; the brachials
do not have overlapping spines; and the cirri are arranged in 10 definite columns on the
centrodorsal. The cirri are 35-40 mm. long with 62-66 segments, and there are
10 arms.

Description. — The centrodorsal is small, truncated conical, with the dorsal pole
entirely covered by elongate tubercles or papillae. The cirrus sockets are arranged in
10 closely crowded columns of 2 or 3 (usually 2) each.

The cirri are XVIII, 62-66, from 35 to 40 mm. long. The longest cirrus segment,
usually the sixth, is from two and one-half to three times as long as broad. The seg-
ments following this slowly decrease in length, in the middle of the cirri being about as
long as broad, or slightly broader than long, and in the terminal fourth or fifth twice
as broad as long. The longer proximal segments have a slight median constriction and
slightly produced distal edges. The short distal segments have a prominent median
dorsal keel which, instead of being sharp along the crest, is broadly rounded. This keel
begins as a production of the distal dorsal border of the segment, but soon involves the
entire dorsal surface becoming, in profile view, rounded triangular, the apex near the
distal end, then evenly rounded, and in the terminal portion more or less straight
along the crest.

The ends of the basal rays are concealed.

The radials are concealed. The IBri are very narrow and bandlike, abutting directly
upon the centrodorsal though everywhere separated from it by narrow subradial clefts,
from 6 to 8 times as broad as long. They are everywhere of the same length, but while
the outer surface of their lateral portions is parallel to the axis of the IBr series, their
median portion is recumbent, making an angle of nearly 90° with that axis so that in
direct lateral view, that is, viewed at right angles to the dorsoventral axis, they are
only about one-third as long in the middorsal line as laterally. The IBr2 (axillaries)
are rhombic with produced and broadly tuncated lateral angles, half again as long as
broad; the lateral edges are about as long as those of the IBrij the distal sides are
strongly concave; a posterior process, about as high as the anterior angle though some-
what broader and more rounded, incises the IBri ; the proximal two-thirds of the median
portion of the axillaries rises into a prominent, but well rounded, median elevation.
The elements of the IBr series are very sharply flattened against their neighbors, this
flattening persisting as far as the base of Pt.

843803—50 10

130 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The 10 arms are all broken off at the first syzygy. The first brachials are short,
deeply incised by the second; their exterior length is much greater than the interior
and more than twice the median, the distal border being strongly concave. The second
brachials are irregularly quadrate with a strong posterior process incising the first; the
proximal three-fourths of the median line is elevated as in the IBr2. The third brachial
(hypozygal of the first syzygial pair) is oblong, very short, about five tunes as broad
as long.

PI is 5.5 mm. long with 19 segments of which the first eight are much larger,
though proportionately shorter, than those succeeding; the second-seventh have thin,
very high, carinate processes that reach a maximum on the fourth, thence rapidly
decreasing in height distally. After the eighth segment the pinnule is relatively slender
and tapers gradually to the tip. In lateral view the pinnule appears enormously swollen
in the proximal three-fifths (first eight segments), the swelling reaching a maximum on
the fourth segment and decreasing rapidly distally; beyond the eighth segment the
pinnule is slender and evenly tapering, composed of segments most of which are about
as long as broad, with numerous spinules along the prismatic ridge.

Locality. — Siboga station 211; southeast of Sindjai, Celebes (lat. 5°40'42" S., long.
120°45'30" E.); 1,158 meters; coarse gray mud, the superficial layer more fluid and
brown; September 25, 1899 [A. H. Clark, 1912, 1918] (1, Amsterdam Mus.).

History. — This species is known only from the single specimen originally described
in 1912 and redescribed and figured in 1918.

STIREMETRA CARINIFERA A. H. Clark

[See vol. 1, pt. 1, fig. 97, p. 159.]

Stiremetra carinifera A. H. CLABK, Crinoids of the Indian Ocean, 1912, p. 211 (description; Inves-
tigator station 232); Unstalked crinoids of the <St'6o(/a-Exped., 1918, p. 161 (in key; range;
references) .

Diagnostic features. — The IBri have the proximal and distal edges prominently
everted, smooth, somewhat wavy, or coarsely tubercular, and a prominent median
rounded carination; the brachials do not bear overlapping spines; and the cirri are
arranged in 10 definite columns on the centrodorsal. There are 10 arms, and the
cirri are 45-50 mm. long with 50-64 segments.

Description.- — The centrodorsal is large and columnar with the sides practically
parallel, 5 mm. in diameter at the base and 3.5 mm. high interradially. The cirrus
sockets are arranged in 10 columns, 3 or 4 sockets to a column, the columns segregated
into five interradial pairs. The two columns of each pan- are separated by a narrow
ridge of moderate height; hi the midradial line the pairs of columns are separated by
deep V-shaped furrows as broad as the adjacent cirrus sockets; the central groove of
these furrows is slightly rounded. The dorsal pole of the centrodorsal is flattened,
with the surface more or less irregular

The cirri are XXXV, 50-64 (usually 57 or 58), from 45 to 50 mm. long. The
first segment is very short, those following gradually increasing in length and becom-
ing about as long as broad on the fifth and nearly or quite twice as long as broad on
the eighth (more rarely seventh), which is a transition segment. The following seg-
ments gradually decrease in length, becoming about as long as broad on the twelfth
or thirteenth, and after the twenty-fifth about twice as broad as long. On the second

A MONOGRAPH OF THE EXISTING CRENOIDS 131

segment beyond the transition segment prominent median terminal spines begin to
appear; these gradually come to involve more and more of the dorsal surface of the
segments, which becomes carinate, so that after the twenty-third the dorsal profile is
straight and parallel to the longitudinal axis of the cirrus as a whole. In the next
four to seven segments a shallow rounded notch is developed in this straight dorsal
profile so that the segments appear to have both a proximal and a distal spine. Be-
yond this point the dorsal processes are of the high strongly carinate type common to
the other species of the genus.

The ends of the basal rays are visible in the interradial angles of the calyx just
over the ends of the ridges separating the individual columns of cirrus sockets in the
interradial pairs; they appear as small dorsoventrally elongated tubercles.

The radials are almost entirely concealed. They bear on their apposed edges,
just over the ends of the basal rays, two tubercles or blunt spines, one on each radial.
Owing to the depth of the midradial furrows on the centrodorsal the subradial clefts
are practically obsolete, only their inner ends being visible as very narrow and very
shallow grooves. The IBri are extremely short, six or more times as broad as long,
chevron-shaped, with both the anterior and posterior edges prominently everted and
smooth, somewhat wavy, or coarsely tubercular; in the middorsal line there is a
prominent median rounded carination.

The IBr2 (axillaries) and arms are lacking.

Notes. — A smaller specimen found with the type appears to represent a younger
stage of the same species. The centrodorsal is truncated conical, 3.5 mm. in diame-
ter at the base and 1.5 mm. broad at the dorsal pole; the height is 3 mm. measured
along the inclination of the sides. The dorsal pole is covered with short spines. In
general the centrodorsal resembles that of the other specimen, but owing to its conical
shape the midradial furrows converge distally.

The cirri are about 40 mm. long and are composed of 54-58 segments of which the
sixth is a transition segment.

The ends of the basal rays are rather more prominent than they are in the other
specimen.

The radials are smooth, without lateral spines. The IBr! have scarcely a trace
of the eversion of then- edges, but possess a higher and sharper median keel, and usually
also a sharp tubercle on the distal border about one-third the distance between the
distal lateral angle and the median line. The IBr2 (axillaries), which are missing in
the other specimen, are approximately triangular (though probably shield-shaped as in
other species of the genus when fully grown), twice as broad as long, with a high and
sharp carination in the proximal two-thirds of the median line and with everted and
spinous distal edges.

On one of the postradial series the IBr2 is not axillary as usual but bears a pinnule
which is essentially similar to P: in related species; the second segment beyond this is
axillary; there is no carination beyond the first pinnule. Only two axillaries are pre-
served, both detached. One has lost both derivatives at the first postaxillary articu-
lation; the other bears on one side one and on the other side three brachials.

Locality.— Investigator station 232; Laccadive Sea (kt. 7°17'30" N., long. 76°54'30"
E.); 786 meters; (A. H. Clark, 1912, 1918] (2, U.S.N.M., 35593; I. M.).

132 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

History. — This species was originally described in my memoir on the crinoids of
the Indian Ocean published in 1912. I said that it appears to be a very distinct species.
The large cirri with numerous segments resemble those of Daidalometra arachnoides,
but the centrodorsal is very much larger and the columns of cirrus sockets are segre-
gated into widely separated pairs instead of being closely crowded. The ossicles of the
calyx and arm bases also lack the spinous edges and the high median carinate processes
so characteristic of that form. The small centrodorsal of S. spinicirra, which is hemi-
spherical or bluntly conical with no differentiation into areas, as well as the short cirri
with few segments, each of which bears a spine, serves to differentiate that species.
Stiremetm acutiradia also has a small centrodorsal with only about 15 cirrus sockets
which are differently arranged. Stiremetra breviradia has cirri with 40-50 segments,
"or a few more," but the centrodorsal is of the type found in D. arachnoides, quite
different from that in the species under consideration. It is probable, however, that
this is the species to which S. carinifera is most closely allied.

In my memoir on the unstalked crinoids of the Siboga expedition published in 1918
carinifera was inserted in the key to the species of Stiremetra and the original reference
was given.

STIREMETRA ACUTIRADIA (P. H. Carpenter)

Antedon acutiradia P. H. CARPENTER, Quart. Journ. Micr. Sci., vol. 27, 1887, pp. 386, 387 (sacculi
present between the side plates; nomen nudum); Challenger Reports, Zool., vol. 26, pt. 60, 1888,
p. 113 (description; Challenger station 175), pi. 11, figs. 3, 4. — HARTLAUB, Bull. Mus. Comp.
Zool., vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrical relationships). — HAMANN,
Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H.
CLARK, Crinoids of the Indian Ocean, 1912, p. 33 (of P. H. Carpenter, 1888= Stiremetra acutiradia).

Thalassometra acutiradia A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 300 (listed).

Stiremetra aculiradia A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed); Crinoids
of the Indian Ocean, 1912, p. 33 (identity), p. 211 (synonymy; locality); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 45 (published references to specimens in the B. M.; Challenger
Station 175); Unstalked crinoids of the Siboga-'Exped., 1918, p. 161 (in key; range; references).

Diagnostic features. — The axillaries are long, longer than broad ; the IBr series and
proximal brachials have a smooth dorsal surface, straight sharp edges, and a sharp
median keel ; the first four brachials do not bear dorsal spines ; and the cirri are arranged
in 10 definite columns on the centrodorsal. The 10 arms are probably about 50 mm.
long.

Description. — The centrodorsal is a somewhat elongated hemisphere with a
papillose dorsal pole. According to the figure the cirrus sockets are arranged in a
single rather crowded marginal row, two sockets in each radial area; the radial areas
are not specially differentiated.

The cirri, according to the description, are about XV; the fourth and some of the
following segments are much longer than broad with traces of dorsal spines.

The raclials are just visible beyond the rim of the centrodorsal. The IBri are
partly free laterally and are deeply incised by the sharp proximal angles of the IBr2
(axillaries), which are longer than broad. Both ossicles are very sharply convex and
almost carinate, but the IBr2 are broader and have a more rounded surface than the
IBr1; which are partly hidden beneath their lateral angles. The elements of the IBr
series and first brachials have straight edges and flattened sides. The inner side of the
second brachial and the hypozygal of the first syzygial pair are also flattened.

A MONOGRAPH OF THE EXISTING CRINOIDS 133

The 10 arms are about 50 mm. long. The first brachials are somewhat incised
for the sharp proximal angles of the second (there is considerable variation in this
respect), both ossicles rising to their line of junction. The sixth and following brachials
are smooth and obliquely triangular, much longer than broad, the later ones becoming
obliquely quadrate.

Syzygies occur between brachials 3+4, again between brachials 17+18, and
distally at intervals of 4 or 5 muscular articulations.

PI is much larger than P2 with wide and thick lower segments which have somewhat
flattened outer sides; the third-fifth segments have their inner edge produced into an
expanded process which is slightly folded upward. Pa and Pa are rather larger than
their immediate successors, but those following are quite small and increase very slowly
in length.

The disk is 4 mm. in diameter and is well plated. The brachial ambulacra are
slightly plated. The pinnule ambulacra are without very definite side plates. The
presence of sacculi is uncertain.

The color hi alcohol is light brownish white.

Notes. — The preceding description is adapted from Carpenter's original description,
with a few additions from the published figure. Carpenter said that this species is
unfortunately represented only by two calices and half a dozen arm fragments with
their pinnules mostly broken. The IBr[ are much compressed laterally so that they
appear as it were at a lower level than the axillaries the lateral angles of which overlap
and partly conceal them. The state of preservation of the pinnules hi the two individ-
uals is unfortunately such that it is impossible to speak positively respecting the presence
or absence of sacculi. But there was no trace of them in any of the few pinnules Car-
penter was able to examine. No entire cirri are preserved, and Carpenter wrote that
the position to which he assigned this species among those with from 30 to 50 spiny
cirrus segments is therefore a somewhat conjectural one. He said that it has so many
points of resemblance with spinicirra, breviradia, and lusitanica that he had little doubt
respecting the character of its cirri.

Carpenter said that this species is most nearly related to S. spinicirra from which
it differs hi the sharper carination and greater relative length of the axillaries.

I examined one of Carpenter's specimens during a visit to the British Museum
hi 1910. It is a small and delicate species and was well figured by Carpenter.

Locality.— Challenger station 175; near Kandavu, Fiji (lat. 19°02' S., long. 177°10'
E.); 2,468 meters; bottom temprature 2.2° C.; globigerina ooze; August 12, 1874
[P. H. Carpenter, 1887, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1909, 1912, 1913,
1918] (1, B. M.).

History. — This species was first mentioned as Antedon acutirculia by Dr. P. H.
Carpenter in 1887, when he said that sacculi are present between the side plates in this
species. The name as it appears here is a nomen nudum.

In the Challenger report upon the comatulids published hi 1888 Carpenter described
and figured Antedon acutiradia on the basis of two calices and half a dozen arm frag-
ments from Challenger station 175. In the description he said that the presence of
sacculi was uncertain and that there is no trace of them in any of the few pinnules
he had been able to examine. Dr. Clemens Hartlaub discussed the systematic and
bathymetrical relationships of Antedon acutiradia hi 1895.

134 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In my first revision of the genus Antedon published in 1907 acutiradia was placed
in the new genus Thalassometra, and in my revision of the family Thalassometridae
published in 1909 it was made the type of the new genus Stiremetra. In my memoir
on the crinoids of the Indian Ocean published in 1912 Stiremetra acutiradia was listed
and the synonymy and range were given. In a paper on the crinoids of the British
Museum published in 1913 I published a short note on one of Carpenter's original
specimens which I had examined at the British Museum in the summer of 1910. In
my memoir on the unstalked crinoids of the Siboga expedition published in 1918
acutiradia was included in the key to the species of the genus Stiremetra and the
synonymy and range were given.

STIREMETRA DECORA, ap. nor.

PLATE 5, FISURE 18

Thalassomelra crassicirra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (small

10-armed spcimen from Albatross station 4107).
Cosmiometra crassicirra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 17; Vid.

Medd. Naturh. Foren K0benhavn, 1909, p. 186; Crinoids of the Indian Ocean, 1912, p. 215;

Unstalked crinoida of the Siboga-Exped., 1918, p. 154.
Sliremetra decora A. H. CLARK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (nomen nudum. Albatross

station 4107), p. 110 (station data).

Diagnostic features. — The axillaries are short, nearly or quite twice as broad as
long, with a high median carination that may be more or less deeply notched in the
middle; the IBri have two long and rather stout blunt spines, one on the distal edge
and one near the proximal edge, and a similar but shorter spine on each side; the
brachials do not bear dorsal spines; and the cirri, in which the first four segments do
not bear dorsal spines, are arranged in 10 definite columns on the centrodorsal. The
10 arms are probably about 50 mm. long, and the cirri have 30-40 segments.

Description. — The centrodorsal is conical, about as high as broad at the base with
a truncated tip which bears several prominent papillae. The surface of the centrodorsal
is not differentiated, the cirrus sockets being arranged hi 10 crowded columns of 2 or
3 each.

The cirri are about XX, with between 30 and 40 segments of which about the fourth
is a transition segment. The transition and next following segments are nearly twice
as long as broad, and the segments in the outer half of the cirri are about half again as
broad as long. The short outer segments bear very high and prominent, rather narrow,
curved dorsal spines.

The ends of the basal rays are visible in the angles of the calyx.

The radials project slightly beyond the rim of the centrodorsal in the midradial line;
their distal border is strongly curved so that they extend well upward in the interradial
angles. The distal edge is turned outward and the dorsal surface is curved so that,
viewed laterally, the radials are seen to curve outward above the rim of the centrodorsal.
In the middle of the dorsal surface of the radials there is a very high transversely
broadened oblong or more or less fan-shaped process with a serrate tip. This process,
which rises abruptly, is about as high as the middorsal length of the radials. The
IBri are about twice as broad as long, somewhat broader proximally than distally, very
strongly rounded dorsally, with the proximal and distal borders slightly produced. In
the median line they bear two long and rather stout blunt spines, one on the distal edge

A MONOGRAPH OF THE EXISTING CRINOIDS 135

and the other below it near the proximal edge, the distal being somewhat the stouter and
longer. There is a similar but shorter spine on each side near the anterolateral angle.
The IBr2 (axillaries) are rhombic, nearly or quite twice as broad as long, with the
lateral angles extending considerably beyond the anterolateral angles of the IBi'i. The
two anterior sides are everted and bear a group of short spines or serrations near the apex
between them. In the proximal two-thirds of the middorsal line there is a high narrow
crest which may be more or less deeply notched in the middle so as to form two points,
of which the distal is the higher and sharper.

The 10 arms were probably about 50 mm. long. The first brachials are somewhat
more than three times as broad as the median length, slightly longer exteriorly than
ulteriorly, with the proximal and distal edges straight and nearly parallel; the borders
are slightly and narrowly swollen and the inner sides are in apposition for their entire
length. A high spine, sometimes laterally broadened, rises abruptly from the middle
of the distal border. The second brachials are larger than the first, irregularly quadrate
with the proximal border extended downward as a rather long broadly rounded process
the inner side of which runs distally at an angle of about 45° so that the inner edges
of the second brachials meet considerably above the anterolateral angles of the first
brachials forming a conspicuous water pore. The borders of the second brachials are
slightly thickened or everted and the middorsal line bears a narrow but distinct carina-
tion which may be produced into a short point at the anterior end, or at both ends. The
first syzygial pair (composed of brachials 3+4) is about one-third again as long as
broad, with the hypozygal and epizygal of equal length; both have a faintly indicated
middorsal carination which on the epizygal may be produced into a point at the distal
end. The next two brachials are oblong, about half again as broad as long, and those
following soon become very obliquely wedge-shaped and about as long as broad, and
distally elongate. The first two brachials following the first syzygial pair may be
somewhat abruptly convex in the middorsal line, but those following are evenly rounded
dorsally with smooth distal edges which are not produced.

Syzygies occur between brachials 3+4, 14+ 15, and 18+ 19, and distally at intervals
of 3 or 4 muscular articulations.

PI is 4.5 mm. long with 11 segments, much longer and stouter than the following
pinnules, stout at the base and tapering to a fine tip. The first three segments are
about as long as broad and those following gradually become elongated and twice
as long as broad terminally. A high and sharp ridge runs along the distal border of the
outer face. P2 is 2.5 mm. long with 7 segments, more slender than Pt and tapering
more gradually ; the first two segments are about as long as broad and the terminal are
half again as long as broad. The following pinnules resemble P2. The distal pinnules
are 4.5 mm. long with about 15-18 segments of which the first is broader than long, the
second is about as long as broad, and those following are mostly about twice as long
as broad. The distal pinnules are much compressed with a sharp carinate ridge running
along the outer side, the ridge on each segment ending in a tuft of spinules.

Locality. — Albatross station 4107 ; Hawaiian Islands; Lae-o Ka Laau Light, Molokai
Island, bearing S. 34°30' E., 12.3 miles distant; 640-649 meters; coral, sand, and foram-
inifera; bottom temperature 5.33° C.; July 24, 1902 [A. H. Clark, 1908, 1909, 1912,
1918, 1949] (1, U.S.N.M., 36079).

136 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

History. — The type specimen of this species from Albatross station 4107 was
recorded in 1908 as a "small ten-armed specimen" of Thalassometra (Cosmiometra)
crassicirra. It is included under the name Cosmiometra crassicirra in the references to
that species published in 1909, 1912, and 1918. Just why this highly distinctive and
utterly different species should have been regarded as the young of Cosmiometra crassi-
cirra is not clear.

STIREMETRA SPINICIRRA (P. H. Carpenter)

Antedon spinicirra P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 112 (descrip-
tion; Challenger station 164), pi. 11, figs. 1, 2. — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No.
4, 1895, p. 131 (systematic and bathymetrical relationships). — HAMANN, Bronn's Klassen und
Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Crinoids of the
Indian Ocean, 1912, p. 33 (identity).

Thalassometra spinicirra A. H. CLARK, Smithsonion Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Stiremetra spinicirra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed); Mem.
Australian Mus., vol. 4, 1911, p. 795 (locality) ; Crinoids of the Indian Ocean, 1912, p. 33 (identity),
p. 210 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 44 (published
references to specimens in the B. M.; Challenger station 164); Unstalked crinoids of the Siboga-
Exped., 1918, p. 160 (in key; range), p. 161 (references). — GISLEN, Ark. Zool., vol. 19, No. 32,
Feb. 20, 1928, p. 7, No. 28 (notes).

Diagnostic features. — All the cirrus segments except one or two of the basal bear
high, broad, and conspicuous dorsal spines; a few of the earlier cirrus segments are
slightly longer than broad; the axillaries are short, much broader than long; the IBr
series and lower brachials have a smooth dorsal surface, a prominent rounded median
carination, straight edges, and flattened sides; the brachials bear moderate over-
lapping carinated spines; and the cirri are arranged in 10 indistinct columns on the
centrodorsal. The arms are about 45 mm. long, and the cirri are about 17 mm. long
with 40-45 segments.

Description. — The centrodorsal is hemispherical or bluntly conical; judging from
the figure the cirrus sockets are arranged hi 10 columns of 2 each, and the surface of the
centrodorsal is unmodified.

The cirri are XX-XXV, 40-45, according to the figure about 17 mm. long; 4 or 5
of the basal segments are slightly longer than broad, the remainder being broader than
long, those hi the distal half twice as broad as long; all but the basal segments (in the
figure all but the first) bear a high, conspicuous, and sharp dorsal spine.

The radials are just visible beyond the centrodorsal. The IBri and IBr2 (axil-
laries) are sharply convex and almost carinate; the figure shows both with a moderately
high carination having a longitudinally straight and transversely sharply rounded
crest. The IBri are partly free laterally and are but little incised by the hexagonal
axillaries, which are much broader than long with a more rounded dorsal surface, though
extending only slightly beyond the distal angles of the IBri. Both the elements of the
IBr series and the first brachials have straight edges and sharply flattened sides. The
inner sides of the second brachials and of the hypozygals of the first syzygial pair are
likewise slightly flattened.

The 10 arms are probably about 45 mm. long. The second brachials are relatively
short and oblong, not projecting much backward into the first, though both are sharply
convex at their line of juncture. The next few brachials are about as long as broad,
and those following are obliquely quadrate, longer than broad. The later brachials
overlap slightly and become somewhat sharply carinate.

A MONOGRAPH OF THE EXISTING CRINOIDS 137

Syzygies occur between brachials 3+4, again between brachials 14+15, and
distally at intervals of 3 or 4 muscular articulations.

PI is larger than P2; its lower segments are relatively stout with somewhat flattened
outer sides, and the inner edges of the third to the fifth segments are slightly carinate.
P, and P2 are small, and those following increase slowly in length, the later ones some-
times showing a faint expansion of the two basal segments.

The color in alcohol is light brownish white.

Notes. — The preceding description is adapted from the original description by
Carpenter, to which are added a few notes taken from his figure. I examined three of
the five original specimens in London in 1910. This is a curious small and delicate
species, with curiously long cirrus spines.

Prof. Torsten Gislen examined these specimens in August 1925. He noted that
the synarthrial pah's are triangular and carinate and slender; the arms are otherwise
smooth and in rather close lateral contact. He remarked that in my key to the genera
of the subfamily Thalassometrinae (that is, the family Thalassometridae as now under-
stood) published in the Siboga report the section referring to Stiremetra should be altered
to "arms distally of Br 2 [the second brachial] without carination."

Locality. — Challenger station 164; near Sydney, M'ew South Wales (lat. 34°08' S.,
long. 152°00' E.); 1,737 meters; bottom temperature 2.28° C.; green mud; June 12,
1874 [P. H. Carpenter, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1909, 1911, 1912, 1913,
1918; Gislen, 1928] (3, B. M.).

History. — This species was first described by Dr. P. H. Carpenter in 1888 under
the name of Antedon spinicirra from five specimens, two of which were much mutilated,
that had been dredged by the Challenger at station 164 off Sydney, New South Wales.
In 1895 Dr. Clemens Hartlaub discussed its systematic and bathymetrical relationships.

In my first revision of the genus Antedon published in 1907 spinicirra was assigned
to the new genus Thalassometra, and in my revision of the family Thalassometridae
published in 1909 it was transferred to the new genus Stiremetra. In my memoir on the
Recent crinoids of Australia published in 191 1 I listed it as one of the species known from
the waters about Australia, and in my memoir on the crinoids of the Indian Ocean
published in 1912 I listed it and gave the range. In a paper on the crinoids of the
British Museum published in 1913 I gave a short note on the three specimens I had
examined during a visit to that institution in 1910. In my report upon the unstalked
crinoids of the Siboga expedition published in 1918 I again listed it and gave its range.

In 1928 Prof. Torsten Gislen published additional notes on the type specimens in
the British Museum he had examined in 1925.

Genus OCEANOMETRA A. H. Clark

Thalassometra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214.

Crotalometra (part) A. H. CLARK, Proc. U. S. Nat. Mus.. vol. 36, 1909, pp. 406, 642.

Oceanomelra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (diagnosis;
genotype Thalassometra gigantea A. H. CLARK, 1908; range; included species); Unstalked crinoids
of the Siboga-Exped., 1918, p. 146 (in key; range), p. 150 (key to the included species). — GISL£N,
Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22.

Diagnosis. — A genus of Thalassometridae in which the arms are rounded dorsally
to the tips; there is no appreciable expansion of the proximal segments of the genital

138 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

pinnules; the cirri are recurved distally, the outer segments with dorsal carinate spines;
the arms are 17-28 in number, the division series and arm bases beset with spines, at
least along their edges; and one or both of the elements of the pairs in the division series
and first two brachials bear a median carinate process. The arms are 1 10-180 mm. long,
and the cirri are 40-85 mm. long with 48-79 segments.

Geographical range. — From Timor and the Kei Islands to the Philippines and
Hawaiian Islands.

Bathymetrical range. — From 55 to 786 (?872) meters.

Thermal range.— From 4.4° to 12.4° C.

Remarks. — The species of Oceanometra are closely related to those of the genus
Thalassometra, from which they differ only in the greater number of arms; in the oc-
currence of keels on one or both the elements of the pairs of ossicles in the division
series and first two brachials; and in having P2 intermediate in character between PI
and P3 instead of small and similar to the following pinnules. For the most part they
are larger and stouter than the species of Thalassometra, though one of the latter,
Th. agassizii, is of equal size. Only one species, 0. annandalei, is known from any
considerable number of specimens; of the other two, 0. gigantea is known only from
the type specimen, and 0. magna from the type specimen and one other.

History. — The first known species of this genus was described under the name of
Thalassometra gigantea in 1908. In 1909 a young individual of 0. annandalei from
Albatross station 5116 was recorded under the name of Crotalometra eupedata; later in
the same year Crotalometra annandalei was described. In 1912 a third species was
described under the name of Thalassometra magna.

The genus Oceanometra was diagnosed in 1916 with the genotype Thalassometra
gigantea A. H. Clark, the other species assigned to the genus being listed as Oceanomtra
magna and 0. annandalei. The status of the genus has since remained unchanged.

KEY TO THE SPECIES IN THE GENUS OCEANOMETRA

a1. The second (but not the first) element in the pairs of ossicles in the division series, and the second
(but not the first) brachials, bear a high sharp median keel; 17 arms 180 mm. long; cirri stout,
75 mm. long with 48-62 (usually 55-60) segments (Hawaiian Islands; 786-872 meters).

gigantea (p. 139)
a2. The first as well as the second element in the pairs of ossicles in the division series, and both the

first and second brachials, bear median keels.

6'. No spines on the dorsal surface of the proximal ossicles except along the borders and the crest
of the keels; ossicles of the division series with irregularly dentate produced lateral borders;
dorsal surface of earlier brachials sparsely spinous; 21-28 arms 120-175 mm. long; cirri large
and stout, 60-85 mm. long with 63-74 segments (Arafura Sea to western Timor; 204-305

meters) magna (p. 1 42)

b2. Dorsal surface of proximal ossicles spinous; ossicles of the division series with smooth lateral
borders which are not produced; dorsal surface of earlier brachials more or less densely spinous;
19-23 arms 110-160 (usually 110-130) mm. long; cirri more slender, 40-65 mm. long with
62-79 segments (Philippines and Malay Archipelago; 55-510 meters) annandalei (p. 144)

A MONOGRAPH OF THE EXISTING CRINOIDS 139

OCEANOMETRA GIGANTEA (A. H. Clark)

PLATE 14, FIGURE 41

[See also vol. 1, pt. 1, figs. 203, p. 239, 364, p. 297; pt. 2, figs. 145, 146, p. 83, 220, p. 168, 284, p. 255,
322, 332, p. 227, 344, p. 229, 859-866, p. 419.]

Thalassometra gigantea A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214 (in key), p. 222
(description; Albatross station 3985); vol. 35, 1908, p. 121 (proximal ornamentation; arm struc-
ture); Araer. Nat., vol. 42, No. 500, 1908, p. 542 (belongs to a group characteristic of the oceanic
area); Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same); Proc. Biol. Soc. Washington, vol. 22,
1909, p. 14 (listed); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 551 (nearest to Th. [Oceanomelra]
annandalef) ; Zool. Anz., vol. 39, No. 11/12, 1912, pp. 425, 426 (compared with Th. [Oceanomelra
magna); Crinoids of the Indian Ocean, 1912, p. 203 (synonymy; locality); Die Crinolden der
Antarktia, 1915, p. 124 (shows the characteristic features of Anthometra adriani).

Oceanometra gigantea A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with 0. magna), p. 150 (in
key; range), p. 151 (references). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser, vol. 45, No.
11, 1934, p. 27. — A. H. CLARK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (Albatross station
3985), p. 99 (station data).

Diagnostic features . — The second, but not the first, clement in the pairs of ossicles
in the division series, and the second, but not the first, brachials bear a high sharp
median keel. This is a large and stout species with 17 arms 180 mm. long, and the
stout cirri 75 mm. long with 48-62 (usually 55-60) segments.

Description. — The centrodorsal is a truncated cone 10 mm. broad at the base, 10
mm. high, and 3 mm. across the broad and flat dorsal pole. Its surface is divided into
5 radial areas by 5 narrow, but high, interradial ridges. The cirrus sockets are ar-
ranged in 2 columns of about 4 each in each radial area, the 2 columns in each radial
area being separated by a bare area which in width is equal to about three-quarters
the transverse diameter of the sockets, or twice the width of the interradial ridges.
The bare areas in the midradial line between the columns of cirrus sockets, the inter-
radial areas, and the distal half of the centrodorsal, which bears no cirri, have a rough
and uneven surface and are thickly covered with small spines.

The cirri are XL, 48-62 (most commonly 55-60), 75 mm. in length. The first
segment is very short and those following gradually increase in length so that the fifth
is about as long as broad and the ninth is about twice as long as its proximal width.
The tenth segment is about half again as long as broad and those succeeding slowly
decrease in length, the sixteenth and seventeenth being about as long as broad, the
distal broader than long, and the terminal about twice as broad as long. The basal
segments are broad in lateral view, but after the sixth they decrease rather rapidly in
width. The ninth segment is broader proximally than distally; its distal end is en-
circled by a narrow band with a polished surface resembling that of the succeeding
segments, the remainder of the surface being dull like that of the segments preceding.
The tenth and following segments are laterally- compressed. After the eleventh or
twelfth a dorsal keel begins to develop which soon becomes high and gradually takes
the form of carinate dorsal spines with a long dorsal crest which is parallel to the axis
of the segments, the dorsal crest becoming shorter and the processes more spinelike
as the segments decrease in length. The opposing spine is triangular, arising from
nearly the whole of the dorsal surface of the penultimate segment, and short, not
reaching half the width of the penultimate segment in height. The terminal claw is

140 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

about as long as the penultimate segment or rather shorter, stout, and moderately
curved. In the shorter more distally situated cirri, which have usually less than 55
segments, the transition segment may be the eighth or even the seventh instead of the
ninth as is most commonly the case in the longer cirri.

The disk is scantily plated, even along the ambulacral grooves, but the brachial
and pinnule ambulacra are well plated. The integument along the ambulacral grooves
and the entire integument of the ventral surface of the arms is raised into very
numerous small papillae which give it a very characteristic appearance.

The ends of the basal rays are visible as tufts of branching spines hi the interradial
angles of the calyx.

There is a deep but narrow, almost triangular, cleft between the centrodorsal and
the radials which is bounded on either side by the proximal cirrus sockets of each
column.

The radials scarcely extend beyond the rim of the centrodorsal; their distal edges
are bordered with a row of long papillae or branching spines. The IBri are short,
three or four times as broad as long, with the proximal border convex so that they are
longer hi the median line than laterally. The proximal and distal edges are somewhat
everted and are fringed with branching spines. The IBr2 (axillaries) are low triangular,
about twice as broad as long, with a high sharp median keel in the proximal two-thirds;
the borders are everted and fringed with spines, the median keel bears a row of spines
along its crest, and there are a few spines scattered over the dorsal surface. IIBr
series are present on 3 of the postradial series; 5 of these are 4(3+4) and the sixth is 2.
The IIBr series resemble the IBr series. Where the IIBr series are 2 the axillary has a
tall sharp median keel like that on the IBr axillary, but the IIB^ is quite without a
trace of one. Where the IIBr series are 4(3+4) both the second and fourth elements
have similar keels, but the first and third are without them. One of the IIBr series
bears a IIIBr series of 2, developed interiorly. The division series and lower brachials
are well rounded dorsally and, though usually just in apposition laterally, are not
laterally flattened.

The 17 arms of the type specimen are 180 mm. long and stout. The first brachials
are wedge-shaped, rather longer exteriorly than interiorly, with the edges everted and
spinous and the dorsal surface evenly rounded. The second brachials are wedge-shaped,
also rather longer exteriorly than ulteriorly, with the edges everted and spinous, and
with a high narrow sharp median keel like that on the axillaries preceding. The follow-
ing 8 brachials are oblong, rather more than twice as broad a long, with the edges
everted and spinous and the dorsal surface thickly covered with small sharp papillae.
The succeeding brachials are triangular, about as long as broad, with both the proximal
and distal edges, but especially the distal, strongly everted and finely spinous, and the
dorsal surface roughened. Distally the brachials become wedge-shaped again, then
elongate. On the earlier triangular brachials the eversion of the proximal edges
gradually becomes obsolete, while that of the distal edges becomes directed forward,
forming a strongly overlapping distal border, and develops longer and more numerous
spines. On the succeeding wedge-shaped brachials the distal edges are strongly over-
lapping and are fringed with rather long spines, while the dorsal surface is covered with
longitudinal rows of distally directed spines.

A MONOGRAPH OF THE EXISTING CRINOIDS 141

Syzygies occur between brachials 3+4, again from between brachials 16+17 to
between brachials 19+20 (in 1 case also between brachials 5+6), and distally at inter-
vals of about 12 or 14, decreasing later to 6 or 9, muscular articulations.

PI is 18 mm. long, stouter than P2 though not markedly so, tapering evenly from
the base to the tip; it is composed of 25 segments which are all about twice as long as
broad, sharply carinate dorsally, and also produced ventrally into a rounded carination.
PD is similar to PI. P2 is 10 mm. long, much less stout than PI, tapering evenly from the
base to the tip, with 15 segments of which the first 4 are broader than long and those
following are about as long as broad, gradually becoming longer than broad. The
segments have a spinous dorsal carination which is more or less overlapping, and their
ventral distal angles are produced so as to give the ventral profile a strongly serrate
appearance. The following pinnules are similar but gradually decrease in length, P6
being 7 mm. long and the 2 succeeding of about the same size, then gradually increase
again, the component segments at the same time becoming smoother and more regular.
The distal pinnules are 15 mm. long with 20 segments of which the first is short and
crescentic, the second is trapezoidal, not so long as broad at the base, and the remainder
are about half again as long as broad, becoming about twice as long as broad distally.
The distal pinnules are strongly prismatic, the prismatic ridge bearing a narrow line of
fine spines.

Locality. — Albatross station 3985; Hawaiian Islands, off Kaui; Hanamaulu ware-
house bearing S. 53°30' W., 6 miles distant; 786-872 meters; bottom temperature 4.4°
C.; gray sand, Foraminifera, and shore deposit; June 10, 1902 [A. H. Clark, 1908, 1909,
1911, 1912, 1915, 1916, 1918, 1949; Gislen, 1934] (1, U.S.N.M., 22687).

History. — • Thalassometra gigantea was described in 1908 from a single specimen
from Albatross station 3985 ; later in the same year its proximal arm structure was de-
scribed in detail and explained (see Part 2, page 105, and figures 145, 146, page 83).
In two other papers published in the same year this species was said to belong to a
group characteristic of the oceanic areas. In my revision of the family Thalassometridae
published in 1909 gigantea was listed as a species of Thalassometra. In 1911 Thalasso-
metra annandalei, originally described in the genus Crotalometra, was transferred to
Thalassometra in which genus it was said to occupy a position near Th. gigantea, and in
1912 Th. gigantea was compared with Th. magna, sp. nov. In my memoir on the crinoids
of the Indian Ocean published in 1912 Thalassometra gigantea was listed and the syn-
onymy and range were given. In my memoir on the crinoids of the Antarctic published
in 1915 the ornamentation of this species was compared with that of Anthometra adriani.
In 1916 Thalassometra gigantea was made the type of the new genus Oceanometra. In
my memoir on the unstalked crinoids of the Siboga expedition published in 1918 Oceano-
metra gigantea was listed, and the synonymy and range were given. Its relationship to
0. magna was discussed. In 1934 Prof. Torsten Gislen discussed the arm structure of
this species.

142 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

OCEANOMETRA MAGNA (A. H. Clark)

PLATE 14, FIGURES 42, 43
[See also vol. 1, pt. 2, fig. 221, p. 171.J

Thalassometra magna A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 425 (description; Siboga
station 251).

Oceanometra magna A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with 0. gigantea), p. 151 (in
key; range; detailed description; sta. 251), p. 274 (listed), pi. 22, fig. 57; Ann. Mag. Nat. Hist.,
Ber. 10, vol. 10, No. 58, October 1932, p. 378 (history; listed), p. 382 (south of western Timor; 140-160
fathoms; notes), pi. 14. — GISLEN, Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934,
pp. 27, 28.

Diagnostic features. — All the ossicles of the division series and both the first and
second brachials bear median keels; no spines on the ossicles of the division series and
first two brachials except along the edges and on the crest of the keels; ossicles of the
division series with irregularly dentate produced lateral borders; dorsal surface of
earlier brachials sparsely spinous. A stout species with 21-28 arms 120-175 mm. long,
and the large and stout cirri 60-85 mm. long with 63-74 segments.

Description. — The centrodorsal is conical with the tip truncated, 5.5 mm. broad at
the base and 5.0 mm. high; the dorsal pole is about 1.5 mm. in diameter, approximately
flat and covered with fine papillae. The cirrus sockets are arranged in 10 columns of
usually four each, the two columns of each radial area being in close contact with those
of adjacent radial areas exteriorly, but separated in the midradial region by a bare
slightly concave area which is proximally nearly or quite as broad as the adjacent cirrus
sockets.

The cirri are XXX-XL, 66-74, from 70-85 mm. long; the longest cirrus segments
are nearly or quite twice as long as broad.

The ends of the basal rays are visible as dorsoventrally elongate tubercles bridging
over the very deep but very narrow subradial clefts.

The radials are very short with a slight rounded median prominence and with a
few small teeth on the distal margin. The IBri are short, between four and five times
as broad as long, broadly V-shaped in a direct lateral view. The proximal and distal
edges are parallel, both slightly everted. The proximal edge bears along the margin a
few short irregularly placed spines. The distal edge bears, on either side of the median
line, about eight regular teeth which begin one third of the distance from the median
line and gradually increase in length to the anterolateral angle; this series of teeth is
continued inward toward the median line by small, and progressively smaller, spines.
The lateral edges are slightly produced and smooth. The anterolateral angles bear a
few prominent blunted spines. In the center of the ossicle there is a prominent and
sharp, though not especially high, median keel. The IBr2 (axillaries) are broadly
rhombic, with the lateral angles truncated, about twice as broad as long; the lateral
edges are not quite so long as those of the IBri and are produced and irregularly and
coarsely spinous; the distal edges and the outer part of the proximal edge are slightly
everted and finely spinous; a prominent keel resembling that on the IBri runs nearly
its whole length. Nine IIBr series are present, all 4(3+4). These resemble the IBr
series and, like them, are prominently carinate; their lateral borders are produced and
irregularly denticulate or spinous. Nine IIIBr series are present, all 4(3 + 4), resembling

A MONOGRAPH OF THE EXISTING CRINOIDS 143

the IIBr series. The produced and denticulate borders extend as far as the base of P2
externally, and as far as the fifth or sixth brachial internally.

The 28 arms are about 120 mm. long and in general resemble those of 0. gigantea.
The first two brachials are carinate. The brachials following have slightly everted and
finely spinous distal edges and the dorsal, but not the lateral, surface covered with very
numerous short fine spines. As the brachials become triangular the proximal edges
lose their eversion, while that of the distal edges becomes more recumbent and more
prominently spinous. The spinosity of the dorsal surface gradually becomes arranged
in definite lines forming a series of sharp, serrate, longitudinal striations.

PD is 14-16 mm. long, comparatively slender as in the other species of the genus
and tapering very gradually to a delicate tip. It is composed of 28-30 segments all
of which are broader than long. The distal outer and distal inner margins of the seg-
ments are sharply and very prominently carinate, this carination being very spinous,
and on the proximal portion of the inner margin coarsely denticulate. A shallow con-
cave trough runs between these ridges. The proximal segments are more or less spinous
on the proximal (dorsal) surface. PP is like PD, but not nearly so long or so large.

PI is 14 mm. long with 26 segments, similar to PD but more slender with the com-
ponent segments somewhat longer, svith their produced borders more spinous, and with
the distal edges of the outer produced and spinous. P2 is 8 mm. long with 17 segments,
much more slender than P! with longer segments distally which have more produced and
spinous distal edges. The following pinnules become progressively more slender with
progressively longer segments which have coarsely spinous distal ends. P3 is 7.5 mm.
long. P4 is 7 mm. long. P6 is 6.5 mm. long. P6 is 6 mm. long. The distal pinnules
are 13 mm. long with 18-20 segments on which the crest of the prismatic ridge is finely
spinous.

The disk, especially along the ambulacral grooves, is thickly beset with small
rounded plates, which become produced along the ambulacra.

Notes. — The specimen from the Danish Expedition to the Kei Islands station 12
has about 40 arms (of which 25 are present) 150 mm. long; one postradial series is broken
off at the distal end of the IBr2, another at the IIBri. Of the IIBr series five are 4(3+4)
and two are 2; three are missing. Of the IIIBr series six are 2 and three are 4(3 + 4).
There are two IVBr series, both next the midradial line but on different postradial series.

The specimen from the Danish Expedition to the Kei Islands station 56 is small with
18 arms about 80 mm. long; the cirri have 39-^3 segments and are 24-32 mm. long.

The specimen from the Danish Expedition to the Kei Islands station 58 is a mag-
nificent example of the species with 24 arms 170 mm. long. Ten IIBr 4(3+4) series
are present. There are four IIIBr series, two on each of two postradial series. On each
ray one is internal and the other, on the other IIBr series, is external. The cirri are
XXXIV, 72-76, from 70 to 75 mm. long.

The specimen from south of western Timor has 21 arms 175 mm. long. Of the ten
IIBr series present eight are 4(3+4) and two are 2, both the latter being on the same
IBr series. There is a single IIIBr 4(3+4) series, which is developed on the outer side
of one of the two IIBr 2 series. The cirri have 63-65 segments and are up to 60 mm. in
length. The dorsal pole of the centrodorsal is strongly convex and rugose.

This specimen differs from the type only in minor details. The type specimen,
which is much broken, was said to have an arm length of about 120 mm. This estimate

144 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

is undoubtedly much too short, as in all other dimensions the type is larger than the
present specimen.

In general appearance this species is intermediate between gigantea and annandalei,
though rather more like the former. It differs from gigantea in having keels on the
proximal elements of the pairs of ossicles forming the division series as well as on the
distal, and on the first brachials as well as on the second; in the more numerously seg-
mented, more slender, and relatively longer cirri; in having more numerous arms (28
instead of 17); in the absence of interradial ridges separating the columns of cirrus
sockets on the centrodorsal; in the much less spinous borders of the division series and
lower brachials; and in having the IIIBr series 4(3 + 4) instead of 2. It differs from
annandalei in being larger and more robust ; in having no spines on the dorsal surface of
the proximal ossicles; in having the ossicles of the division series with irregularly dentate
produced lateral borders instead of smooth; in the much less spinous dorsal surface of
the earlier brachials; and in the larger and stouter cirri.

Localities. — Siboga station 251 ; Arafura Sea, west of the Kei Islands (lat. 5°28'24"
S., long. 132°00'12" E.); 204 meters; hard coral sand; December 8, 1899 [A. H. Clark,
1912, 1916, 1918, 1932; Gislen, 1934] (1, Amsterdam Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 12; 320 meters;
sand; April 9, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 345 meters;
mud; May 10, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 58; 290 meters;
mud; May 12, 1922 (1, C. M.).

South of western Timor (lat. 10°26'24" S., long. 123°46'18" E.); 256-292 meters;
cable repair ship The Cable, Eastern Australasia and China Telegraph Company, July
1, 1928 [A. H. Clark, 1932] (1, B. M.).

Geographical range. — From the Kei Islands to Timor.

Bathymetrical range. — From 204 to 345 meters.

History. — This species was originally described in 1912 from a single specimen
from Siboga station 251 under the name of Thalassometra magna. In 1916 it was
listed as Oceanometra magna, and it was redescribed and figured under that name in
1918. In 1932 I recorded and gave notes on a second specimen that had been brought
up by the cable repair ship The Cable off Timor, and in 1934 Prof. Torsten Gislen
discussed the arm structure of this species.

OCEANOMETRA ANNANDALEI (A. H. Clark)

PLATE 15, FIGURES 45, 46
[See also vol. 1, pt. 2, figs. 222, p. 173, 515, 516, p. 283.]

Crotalometra eupedata (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 406 (Albatross
station 5116; characters).

Crotalometra annandalei A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 642 (description;
Malay Archipelago, 30 fms.).

Thalassometra annandalei A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 551 (referred to
Thalassometra; near gigantea; Albatross station 5116 [originally recorded as eupedata], 5280, 5503,
5504, 5506, 5536; abnormal specimens); Zool. Auz., vol. 39, No. 11/12, 1912, p. 425 (compared
with Th. [Oceanometra] magna); Crinoids of the Indian Ocean, 1912, p. 195 (synonymy; detailed

A MONOGHAPH OF THE EXISTING CRINOIDS 145

description; localities), fig. 35, p. 196; Die Crinoiden der Antarktis, 1915, p. 125 (shows char-
acteristic features of Anthomelra adriani).

Oceanometra annandalei A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606
(listed) ; Unstalked crinoids of the Siboga-Exped., 1918, p. 151 (in key; range), p. 153 (references). —
GISL£N, Zool. Bidrag Uppsala, vol. 9, 1924, p. 80, fig. 79, p. 81 (syzygial face); Kungl. Fysiogr.
Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 22, 23.

Diagnostic features. — All the ossicles of the division series and the first two brachials
bear median keels and have smooth lateral borders which are not produced and a more
or less spinous dorsal surface; the dorsal surface of the earlier brachials is more or less
densely spinous. This is a rather slender species, with slender cirri; the 19-23 (usually
20) arms are 110-160 (usually 110-130) mm. long, and the cirri are 40-65 mm. long
with 62-79 segments.

Description. — The centrodorsal is columnar with the tip truncated conical as in
Asterometra, 5 mm. high and about 5 mm. broad at the base. The cirrus sockets are
arranged in 10 columns, of usually three each, the columns of adjacent radial areas being
closely crowded and with the sockets more or less alternating, while the two columns in
each radial area are separated in the midradial line by a slightly concave median area
of about half their width. The polar area of the centrodorsal has five more-or-less
marked interradial ridges which terminate in five small tubercles about the apex.

The cirri are XXX, 62-79, 65 mm. long, and comparatively slender. The first
three segments are approximately equal, short, about twice as broad as long. The
segments following gradually increase in length, becoming about as long as broad on
the fifth or sixth, and from half again to nearly twice as long as broad on the eighth or
ninth. The next three or four segments are similar, the length then very slowly de-
creasing, the segments in the middle of the cirri being about as long as broad and those
in the distal portion about twice as broad as long. The eighth, ninth, or tenth is a tran-
sition segment. Shortly after the transition segment the median portion of the distal
dorsal edge of the segments begins to become prominent. This very slowly increases
in height, arising from progressively more and more of the dorsal surface of the seg-
ments, which become progressively more and more carinate so that in the terminal 45 or
50 the dorsal surface is produced into a sharp, thin keel, straight in front, convex pos-
teriorly, the outer edge parallel with the median line of the cirrus, in height equal to
about one-third the lateral width of the segment which bears it. The opposing spine
is small and blunt, arising from the entire dorsal surface of the penultimate segment,
the apex subterminal or central, in height equal to about one third the diameter of the
penultimate segment. The terminal claw is small, about equal in length to the penulti-
mate segment, stout and moderately curved. The cirri are rounded in section in the
basal third, later becoming strongly compressed laterally and, when viewed from the
side, somewhat broader.

The ends of the basal rays are visible as dorsoventrally elongated tubercles in the
angles of the calyx. Deep, though narrow, subradial clefts are present.

The radials are very short, convex proximally and concave distally, with a small
sharp tubercle in the median portion of the proximal border. The IBri are about three
times as broad as long with the proximal border convex and the distal border concave,
in close lateral opposition and extending rather well up into the angles of the calyx; the
lateral edges are more or less denticulate, and there is a low, though sharp, serrate

146 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

median keel. The IBr2 (axillaries) are slightly longer than broad, shield-shaped, with
the proximal border produced into a rounded projection incising the IBri, the anterior
edges concave, the anterior angle somewhat produced, and the lateral edges somewhat
denticulate ; there is a sharp serrate median keel in the proximal two-thirds. The IIBr
series are 4(3+4), rarely 2, and are strongly convex dorsally; they are in close lateral
apposition and are sharply flattened laterally, like the IBr series; the lateral edges are
produced and strongly denticulate. The syzygial pair formed by the two outer elements
is centrally constricted with the lateral angles produced as in the other species of the
genus.

The 20 arms are 115 mm. long. The first brachials are short, slightly longer ex-
teriorly than interiorly, interiorly united, and somewhat incised by the second, which are
nearly twice as large and have a rounded posterior projection. The first and second
brachials, like the two elements of the IBr series, have a slightly marked median can-
nation. The first syzygial pair (composed of brachials 3+4) is not quite so long as
broad and is somewhat constricted centrally. The next five or six brachials are almost
oblong, about twice as broad as long, with the dorsal profile rather strongly concave.
The brachials following become wedge-shaped and soon triangular, nearly as long as
broad, and after the middle of the arm wedge-shaped again and about as long as broad.
At first the arms are evenly rounded dorsally, but after the basal third they gradually
become compressed and more sharply rounded dorsally, and in the outer half very
narrow and very sharply rounded dorsally, though not really carinate. After the basal
third of the arms the brachials develop slightly projecting and finely spinous distal edges.
The dorsal, but not the dorsolateral, side of the fourth and following brachials is covered
with fine short spines which gradually become coarser after the proximal third of the
arm and tend to arrange themselves in longitudinal lines. The ossicles of the division
series and arm bases have strongly denticulate borders.

Syzygies occur between brachials 3+4, again from between brachials 25+26 to
between brachials 35 + 36 (usually in the vicinity of the twenty-ninth), and distally at
intervals of from 5 to 17 (usually from 7 to 9) muscular articulations.

PD 12 mm. long, moderately stout in the proximal half but becoming slender distally,
with about 20 segments all of which are approximately as long as broad, those in the
basal two-thirds being strongly carinate. P! 10 mm. long, similar to PD but less stout
basally. P2 6 mm. long, much more slender than PI, tapering evenly from the base to
the tip, with 15 segments of which the proximal four or five are about as long as broad,
those following becoming longer than broad and about twice as long as broad terminally.
P3 is similar, 6 mm. long. P4 and the following pinnules are 5 mm. long with about 13
segments, less slender distally than those preceding; the segments have slight over-
lapping spines developed on the distal edge along the dorsal crest. The distal pinnules
are 10 mm. long, rather slender, composed of about 20 segments of which the first is
short and crescentic, the second is trapezoidal and about as broad distally as its median
length, and those following are half again as long as broad, with the terminal four or
five disproportionately small; the dorsal crest is sharp and somewhat spinous.

The perisome over the gonads is encased in well-formed and definite plates of very
different sizes and shapes some of which, near the borders of the piunulars, are longi-
tudinally elongated. The side- and covering-plates resemble those of 0. gigantea.

A MONOGRAPH OF THE EXISTING CRINOIDS 147

Notes. — Of the five specimens from Albatross station 5367 one has 20 arms 85 mm.
long and the cirri 40-47 mm, long; all the IIBr series are 4(3 + 4). Another has 19
arms 115 mm. long and the cirri 40-45 mm. long; of the nine IIBr series seven are
4(3 + 4) and two are 2. Another has 23 arms 110 mm. long, and the cirri 40^45 mm.
long; the ten IIBr series and the three IIIBr series are 4(3+4). Another has 19 arms;
of the nine IIBr series six are 4(3 + 4) and three are 2. The fifth has 20 arms with the
ten IIBr series all 4(3+4).

One of the three specimens from Albatross station 5503 has 20 arms 120 mm. long;
another has 20 arms 115 mm. long; and the third has 19 arms 130 mm. long.

Of the two specimens from Albatross station 5506 one has 19 arms 90 mm. long and
the other is small with 15 arms.

The specimen from Albatross station 5280 has 21 arms 130 mm. long and the cirri
50-60 mm. long; there are four IIBr 2 series, two of which bear externally IIIBr 4(3+4)
series.

A small specimen from Albatross station 5116 has 11 arms 60 mm. long; one IIBr
4(3+4) series is present.

All the specimens from the Philippines are somewhat smaller and more slender
than the type specimen in the Indian Museum, with which they were compared directly.
The division series and lowest brachials are usually slightly more spinous and thus more
nearly like the brachials immediately following; there is, however, considerable variation
in this feature.

Abnormal specimen. — The specimen from Albatross station 5536 has 22 arms 160
mm long, and the cirri 40-50 mm. long. Of the nine IIBr series eight are 4(3+4) and
one is 2. The axillary of one of the IIBr 2 series bears on its inner face another axillary
and on its outer face the first elements of a IIIBr 2 series which is supported equally
by the IIBr axillary and by the outer side of the IIIBr axillary.

Localities. — Investigator; Malay Archipelago; 55 meters [A. H. Clark, 1909, 1912,
1915, 1916, 1918] (2, U.S.N.M., 35577; I. M.).

Albatross station 5367; North Balabac Strait; Balabac Light bearing S. 65° W., 14.3
miles distant (lat. 8°06'00" N., long. 117°17'10" E.); 124 meters; coral sand; January
5, 1909 (5, U.S.N.M., 35571, 35948).

Albatross station 5504; in the vicinity of northern Mindanao; Macabalan Point,
Mindanao, bearing S. 39° E., 6 miles distant (lat. 8°35'30" N., long. 124°36'00" E.);
366 meters; bottom temperature 12.4° C.; green mud; August 5. 1909 [A. H. Clark,
1911, 1912, 1915, 1918] (1, U.S.N.M., 35573).

Albatross station 5503; in the vicinity of northern Mindanao; Macabalan Point
Light, Mindanao, bearing S. 31° E., 6.6 miles distant (lat. 8°36'26" N., long. 124°36'08"
E.); 413 meters; bottom temperature 11.7° C.; green mud; August 4, 1909 [A. H.
Clark, 1911, 1912, 1915, 1918] (3, U.S.N.M., 35570).

Albatross station 5501; in the vicinity of northern Mindanao; Macabalan Point
Light, Mindanao, bearing S. 35' E., 8.2 miles distant (lat. 8°37'37" N., long. 124°35'00"
E.); 391 meters; bottom temperature 12.4° C.; fine sand and gray mud; August 4,
1909 (1, U.S.N.M., 35959).

Albatross station 5506; in the vicinity of northern Mindanao; Macabalan Point,
Mindanao, bearing S. 41° E., 12.2 miles distant (lat. 8°40'00" N., long. 124°31'45" E.);

148 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

479 meters; bottom temperature 11.7° C.; green mud; August 5, 1909 [A. H. Clark,
1911, 1912, 1915, 1918] (2, U.S.N.M., 35574).

Albatross station 5536; between Negros and Siquijor; Apo Island (C.) bearing S.
26° W., 11.8 miles distant (lat. 9°15'45" N., long. 123°22'00" E.); 510 meters; bottom
temperature 11.9° C.; green mud; August 19, 1909 (1, U.S.N.M., 35572).

Albatross station 5280; China Sea, off southern Luzon; Malavatuan Island (N.)
bearing S. 60° W., 6.1 miles distant (lat. 13°55'20" N., long. 120°25'55" E.); 353
meters; bottom temperature 9.8° C.; gray sand; July 17, 1908 [A. H. Clark, 1911, 1912,
1915, 1918] (1, U.S.N.M., 35575).

Albatross station 5116; Balayan Bay; Sombrero Island bearing N. 69° E., 2.5 miles
distant (lat. 13°41'00" N., long. 120°47'05" E.); 366 meters; bottom temperature
10.1° C.; January 20, 1908 [A. H. Clark, 1909 (as Orotalometra eupedata), 1911, 1912,
1915, 1918] (1, U.S.N.M., 35576).

Geographical range. — From the Malay Archipelago northward to Luzon, Philip-
pine Islands.

Bathymetrical range. — From 55 to 510 meters; the average of 9 records is 339
meters.

Thermal range. — From 9.8° to 12.4° C.; the average of 7 records is 11.4° C.

History. — A supposed young specimen of Crotalometra eupedata recorded on May
13, 1909, from Albatross station 5116 proved to belong to this species which was described
on June 19, 1909, under the name of Crotalometra annandalei from two specimens
dredged by the Koyal Indian Marine Survey steamer Investigator in the Malay Archi-
pelago in 30 fathoms. In 1911 I recorded Thalassometra annandalei from Albatross
stations 5280, 5367, 5503, 5504, 5506, and 5536, giving notes on the specimens, and
redetermined the small 11-armed specimen from station 5116. In my description of
Thalassometra (Oceanometra) magna published in 1912 I compared it with Thalassometra
annandalei. In my memoir on the crinoids of the Indian Ocean published later in
1912 I redescribed and figured Thalassometra annandalei and gave the synonymy and
range. In my memoir on the crinoids of the Antarctic published in 1915 I compared
the characteristic features of Anthometra adriani with corresponding features in Thalas-
sometra annandalei. In 1916 I first listed this species as Oceanometra annandalei. In
my memoir on the unstalked crinoids of the Siboga expedition published in 1918 I
included annandalei in the key to the species of Oceanometra and gave the synonymy
and range.

Prof. Torsten Gislen in 1924 and 1934 discussed various features in the structure
of Oceanometra annandalei.

Genus LEILAMETRA A. H. Clark

Leilametra A. H. CLARK, Ann. Mag. Nat. Hist., ser. 10, vol. 10, No. 58, October 1932, p. 379 (diagnosis;
genotype L. necopinata, sp. nov.).

Diagnosis. — A genus of Thalassometrinae including species with 10 arms in which
the elements of the division series and lower brachials have spinous borders and the
brachials beyond the proximal have a spinous dorsal surface and very spinous distal
edges; the cirri are very long, with up to 83 segments, slender, and nearly straight, being
only slightly recurved distally, composed of segments with produced and spinous distal
ends, but broadly rounded dorsally instead of carinate, the penultimate without an

A MONOGRAPH OF THE EXISTING CRINOIDS 149

opposing spine ; P2 resembles PI and is only very slightly smaller, and the segments of
the genital pinnules are not expanded.

Geographical range. — Known only from south of Lombok, in the Lesser Sunda
Islands.

Bathymetrical range. — Known only from 1,097 meters.

Remarks. — The genus Leilametra is closely related to Thalassometra from which it
differs in the long straight cirri the distal segments of which are without dorsal processes
and in having Pj resembling P] instead of P3 and the following pinnules. The relation
between Leilametra and Thalassometra is somewhat analogous to that between Craspe-
dometra and Heterometra.

LEILAMETRA NECOPINATA A. H. Clark

PLATE 16, FIGURES 48, 49

Leilametra necopinata A. H. CLARK, Ann. Mag. Nat. Hist., ser. 10, vol. 10, No. 58, October 1932, p. 378
(listed), p. 379 (south of Lombok, 600 fathoms; description), pi. 13; Proc. Biol. Soc. Washington,
vol. 47, Feb. 9, 1934, p. 10 (new genus and species discovered by The Cable).

Description. — The centrodorsal is of moderate size, apparently columnar basally,
with the bare dorsal pole low, rounded, conical, 3 mm. in diameter. The cirri are ar-
ranged in 10 columns of 2, rarely 3, each, the columns being closely crowded, though the
proximal cirrus sockets are somewhat more separated in the radial than in the interradial
lines.

The cirri are XXII, 55-83 (in the longest cirri nearer the latter), up to 90-95 mm.
in length, and slender. They are of uniform width in the proximal half, in the distal
half very slowly and almost imperceptibly tapering to a fine tip. The first segment is
very short, the second and third are about three times as broad as long, the fourth is
twice as broad as long, the fifth is longer, nearly as long as broad, the sixth is about one-
third again as long as broad, and the seventh, which is a transition segment, is about
twice as long as broad or slightly longer. The next three or four segments are of the same
length, after which the length of the segments very slowly decreases so that those in the
distal half of the cirri are from half again to twice as broad as long, the terminal segments
again increasing in length so that the antepenultimate is about as long as broad. After
the transition segment the distal ends of the segments dorsally become slightly produced
and very finely spinous, at first only in the central portion, but later more and more
extensively, finally involving the entire distal edge on the dorsal side. The dorsal
profile of the segments is straight, distally becoming somewhat convex, and rises from
the proximal to the distal end, so that the dorsal profile of the cirri as a whole is serrate.
But the dorsal surface of the cirri is always broadly rounded, never becoming carinate.
There is no opposing spine. The terminal claw is long, longer than the segment that
bears it, slender, evenly tapering, and slightly and evenly curved.

The ends of the basal rays are conspicuous .as rhombic areas in the interradial
angles of the calyx. Deep but narrow subradial clefts are present.

The radials are short and bandlike, about eight times as broad as long in the
median line, shorter laterally than in the median line, evenly curved, and with the
median portion raised into a low and very broadly rounded elevation. The IBri are
about four times as broad as long, with the proximal and distal edges parallel and the
lateral borders produced so as to be in contact and more or less broadly swollen. The
anterolateral angles are broadly truncated, so that a rather narrowly rhombic water-

150 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

pore with the long axis at right angles to the dorso ventral axis of the animal is formed.
The midradial line rises into a broadly rounded elevation. The IBr2 (axillaries) are
twice as broad as long or somewhat broader, triangular, with the lateral angles rather
broadly truncated. The proximal border is very slightly convex in the middle and is
slightly bowed downward over the truncated anterolateral angles of the IBri. The
distal edges are slightly everted and are armed with exceedingly fine spines, and the
proximal two-thirds of the median line is raised into a low and broadly rounded eleva-
tion. The outer portions of the proximal border are produced into a slightly everted
flange with a plain or sometimes broadly crenulate edge.

The 10 slender arms are 180 mm. in length. The first brachials are wedge-shaped,
about four times as broad as the median length, and nearly twice as long exteriorly as
interiorly. The proximal border is slightly convex and is slightly everted. The inner
borders of the two first brachials borne by each axillary are in contact and are slightly
everted in the proximal half or two-thirds, the distal portion being slightly swollen and
sometimes armed with a spine or several spines. The distal border is very slightly
concave and the lateral portions are very slightly prominent. The second brachials are
about twice as large as the first brachials, and are trapezoidal. They are in contact
ulteriorly, and there is a narrow horizontally elongated water pore beneath their inner
ends. The first syzygial pair (composed of brachials 3 + 4) is approximately oblong,
half again as broad as long. The hypozygal is slightly longer interiorly than exteriorly,
and the epizygal has practically parallel sides. The next three or four brachials are
somewhat irregularly oblong, about three times as broad as long, with the dorsal surface
roughened and the proximal and distal edges slightly everted and armed with exceed-
ingly fine spines. The succeeding brachials are very obliquely wedge-shaped, almost
triangular, half again as broad as the greatest length, with the surface roughened and
the proximal and distal edges armed with a band of very fine spines, soon becoming
triangular and somewhat longer, at the middle of the arm becoming obliquely wedge-
shaped again, and nearly or quite as long as broad, and terminally longer than broad
with very oblique ends. After the proximal third of the arms the roughness of the
dorsal surface of the brachials becomes more pronounced, resolving itself into numerous
short spines with a broad base which are directed distally and tend to be arranged in
rows, and at the same time the production and spinosity of the distal edges of the
brachials increases.

The first syzygy is between brachials 3 + 4, the second usually between brachials
15+16, sometimes between brachials 16+17, and once between brachials 17+18, and
the third is from between brachials 19 + 20 to between brachials 24 + 25. The distal
intersyzygial interval is from 5 to 12 (usually 7 or 8) muscular articulations.

PI is 10 mm. long and is composed of 18 segments. It is stout basally and tapers
evenly and gradually to a delicate tip. The first segment is about half again as broad
as long, and those following gradually increase in length to the eighth, which is about
as long as broad or slightly broader than long. The following segments are similar,
becoming somewhat longer terminally. The outer side of the segments is sharply and
broadly flattened. The edge of the segments on the distal side of the flattened outer
surface is broadly rounded, somewhat elevated, and finely spinous; viewed from the
side it is seen to be somewhat convex. The proximal and distal angles of the outer
ends of the segments from the fourth or fifth onward extend beyond the bases of the

A MONOGRAPH OF THE EXISTING CRINOIDS 151

segments succeeding. The second and following segments bear high carinate processes
with the crest parallel to the axis of the pinnule.

P2 is 8 mm. long with 14 or 15 segments. It resembles PI and is only slightly
less stout basally.

P3 is 6 mm. long with 11 or 12 segments and resembles the pinnules preceding,
but is less stout. As in the preceding pinnules, the carinate processes on the segments
are well developed.

P4 is 6 mm. long with 10 segments and resembles P3, but the carinate processes
on the segments are not quite so strongly developed.

P6 is 6 mm. long with 10 segments and resembles P4. On the next few pinnules
the carinate processes on the segments disappear.

The distal pinnules are 15 mm. long with 18 or 19 segments.

The color is yellow with the basal portion of the cirri, including the proximal two-
thirds of the transition segment, darker, especially on the transition segment itself.

Locality.— South of Lombok Island (lat. 8°59'54" S., long. 115°50'48" E.); 1,097
meters; cable repair ship The Cable, Eastern Australasia and China Telegraph Co.
[A. H. Clark, 1932, 1934] (1, B. M.).

Genus THALASSOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 107, and fol-
lowing authors.

Thalassometra A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 359 (diagnosis; geno-
type Antedon villosa A. H. Clark, 1907); Bull. Mus. Comp. Zool., vol. 51, No. 8, 1908, p. 245
(characters; genotype) ; Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136 (referred to the Thalas-
sometridae) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 211 (referred to the Thalassometridae),
p. 212 (occurs in Japan and the Crozet, Aleutian, Galdpagos and Hawaiian Islands), p. 275
(proximal ornamentation); Amer. Nat., vol. 42, No. 503, 1908, p. 723 (range; habitat); Geogr.
Journ., vol. 32, No. 6, 1908, p. 602 (range; habitat); Proc. Biol. Soc. Washington, vol. 22, 1909,
p. 1 (revision), p. 14 (list of species included in the genus as restricted); Vid. Medd. Naturh.
Foren. K0benhavn, 1909, p. 138 (transition segment in the cirri comparable to that of Comatella
maculata); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 551 (Crotalomelra [Oceanomelra] annandalei
referred to this genus); vol. 40, 1911, p. 12 (occurs in deep water in the Atlantic, but does not
intrude on Polar-Pacific species) ; Crinoids of the Indian Ocean, 1912, p. 10 (2 species occur in
the Hawaiian Islands), p. 11 (occurs both east and west of Ceylon), p. 12 (represented in the
Red Sea and in the southeastern African regions), p. 14 (certain species are characteristic of the
oceanic fauna; absent from the American side of the Atlantic, and from the European side north
of the Bay of Biscay), p. 23 (distribution in the East Indies in detail), p. 59 (in key), p. 195
(original reference; genotype); Internat. Rev. gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4
and following (occurs in both Atlantic and Indo-Pacific; range); Die Crinolden der Antarktis,
1915, p. Ill (synonymy; range), p. 181 (both Atlantic and Indo-Pacific; range in each) ; Unstalked
crinoids of the Si&oga-Exped., 1918, pp. 145, 147 (in key; range), p. 166 (key to the included
species); The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range; list of Atlantic
species). — MORTENSEN, Handbook of the echinoderms of the British Isles, 1927, p. 25 (northeast
Atlantic species; in key). — GISLEN, Vid. Medd. Dan'sk Naturh. Foren. K0benhavn, vol. 83,
1927, p. 6; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7.— A. H. CLARK, Journ. Linn. Soc. (Zool.),
vol. 36. No. 249, April 1929, p. 651. — GISL^N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45,
No. 11, 1934, pp. 18, 20.

Diagnosis. — A genus of Thalassometridae in which the arms are dorsally rounded
to the tips; the lower segments of the genital pinnules are not appreciabty expanded;
PI is much larger and stouter than P2, which resembles the pinnules following; the cirri
are recurved distally, the short outer segments bearing dorsal spines; the division series

152 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and arm bases are more or less thickly beset with small spines, at least along the borders
of the ossicles; and the arms are less than 15 (usually 10) in number, with the IIBr
series, when present, usually 4(3 + 4), sometimes 2.

Geographical range. — From the western Aleutian Islands, the Galapagos Islands
and Panama, and the Kermadec Islands westward to east Africa from Sokotra to the
Crozet Islands, and from Tristan da Cunha and Ascension Island northward to the
Canary Islands.

Bathymetrical range. — From 598 to 2,925 meters.

Thermal range.— From 1.2° to 7.88° C.

Remarks. — The genus Thalassometra is closely related to Oceanomftra, though on
the basis of our present meager knowledge it appears to be quite distinct. It is also
closely related to Leilametra, which differs from it only in the long straight tapering
cirri without dorsal spines or carination, recalling the relation between Craspedometra
and Heterometra, and in the large size of P2, which is intermediate in size and character
between PI and P3 instead of being small like P3. The differences between Thalassometra
and Stiremetra are not very significant, though they appear to be constant.

Nearly all the species of Thalassometra are known only from a few mutilated indi-
viduals from a single dredge haul, and in most cases the descriptions leave much to be
desired.

The 16 species of the genus form, on the whole, a fairly homogeneous unit. The
species with numerous coarse spines or tubercles — bispinosa, electrae, agassizii, and
villosa — in which the IIBr series are 2 instead of the usual 4(3+4) may possibly repre-
sent a generic type distinct from those with very fine spines, but as yet we do not know
enough about them to enable us to form any very definite opinion.

This genus and Stiremetra are the only representatives of the family Thalassometri-
dae at depths greater than 1,600 meters.

History. — As originally proposed in my first revision of the old genus Antedon
published in 1907, the genus Thalassometra included all the species known at that time
that are now included in the family Thalassometridae, with the exception of (Parametra)
compressa and orion, which were placed in Charitometra, but transferred to Thalasso-
metra in the following year. Since then Thalassometra has been progressively restricted
in scope by the establishment of Stylometra in 1908; Cosmiometra, Crotalometra, Para-
metra, Stenometra, and Stiremetra in 1909; Aglaometra in 1913; Daidalometra (separated
from Stenometra) in 1915; Oceanometra in 1916; and Horaeometra and Lissomctra (sepa-
rated from Parametra) in 1918. Leilametra was established in 1932, based upon a
newly discovered type, and Koehlermetra is separated from Crotalometra herein.

KEY TO THE SPECIES IN THE GENUS THALASSOMETRA

a1. Centrodorsal with the cirri arranged in 10 definite columns, two in each radial area.

6>. Edges of the elements of the division series and lower brachials, and sometimes the dorsal surface

also, with coarse blunt spines or tubercles, never finely spinous.

c1. Elements of the division series and lower brachials bordered with numerous coarse blunt
spines; eighth and following brachials each with 2 or 3 long curved spines near the distal
edge; lower pinnules very spiny; 10 arms about 50 mm. long and the cirri about 17 mm.
long with 30-35 segments (between Marion Island and the Crozets; 2,925 meters).

bispinosa (p. 154)

A MONOGRAPH OF THE EXISTING CRINOIDS 153

e1. Elements of the division series and lower brachials with large well-spaced tubercles on the
dorsal surface; lower pinnules not spiny; 10 arms; cirri about 28 mm. long with 29-43

(usually about 40) segments (northwest of Sokotra; 2,194 meters) electrae (p. 156)

6*. Edges of the elements of the division series, and often the dorsal surface also, with numerous

fine spines.
c1. Cirri with more than 30 segments.

dl. Cirri with 60-71 segments, 45-50 mm. long.

e1. Elements of the division series and lower brachials smooth dorsally, or with a few low
inconspicuous tubercles; synarthrial tubercles rather prominent, but no median carina-
tion; 10-13 arms 80-120 mm. long, and the cirri 50 mm. long with 62-71 segments
(Kurrachi to the Maldive Islands and southwestward to Mozambique; 797-1,398

meters) attenuata (p. 163)

e2. Elements of the division series and lower brachials with spines on the dorsal surface,

and with a more or less narrow spinous median carination.

/'. Elements of the division series and lower brachials with the edges all around strongly
everted and coarsely spinous, with a coarsely spinous median carination, and with
a few coarse spines scattered over the dorsal surface; 10 arms; cirri 30-45 mm. long,
with 48-66 (usually 54-66) segments (Timor Sea to Luz6n; 214-960 meters).

hirsuta (p. 165)

f. Elements of the division series and lower brachials with the edges less strongly everted;
spinosity coarser, the spines more uniform in size and more thickly distributed over
the dorsal surface of the ossicles, also larger, so that there is less difference between
the spines of the dorsal surface and those of the everted edges; median carination
more rounded and studded with spines resembling those of the general dorsal surface;
10 arms about 95 mm. long, and the cirri 45 mm. long with 57+ segments (Flores

Sea; 794 meters) margaritifera (p. 168)

(P. Cirri with 40-55 segments, 30-40 mm. long.

e1. Spines confined to the edges of the elements of the division series and earlier brachials.
/>. Elements of the division series and first two brachials with the proximal and distal
edges prominently everted and irregularly and coarsely dentate, the dentations
with numerous fine spines on their tips, the lateral borders perfectly plain without
spines or tubercles and sharply, though narrowly, flattened against their neighbors;
10 arms; cirri 40 mm. long with 34—46 segments (Maldive and Nicobar Islands, 384

meters) marginata (p. 168)

P. Elements of the division series and lower braehials with the proximal and distal edges

not dentate, evenly spinous.

gl. Elements of the division series and first two brachials bordered with thickly set
spines; triangular proximal brachials with projecting distal edges which increase
in prominence distally, in the distal third of the arms becoming long curved over-
lapping spines; 10-12 (usually 10) arms 110 mm. long, and the cirri 32 mm. long
with 50-55 segments (Hawaiian Islands; 545-641 meters) ..hawaiiensis (p. 170)
g2. Elements of the division series and first two brachials with the edges finely spinous;
distal edges of the brachials not produced; 10 arms 40 mm. long, and the cirri 30
mm. long with 40 segments (Sagami Bay, Japan; 631 meters)._latipinna (p. 171)
e2. Elements of the IBr series and lower brachials with numerous thickly set very fine spines
on the dorsal surface; 10 arms 60-80 mm. long, and the cirri 30 mm. long with 50-55

segments (Meangis Islands to southwestern Japan; 804-914 meters gracilis (p. 173)

c2. Cirri with 25 segments; elements of the division series and first two brachials with sharp
straight edges fringed with spines, and very slightly flattened sides; 10 arms 30 or 35 mm.

long (Kermadec Islands; 1,152 meters) echinata (p. 176)

'. Centrodorsal with the cirrus sockets never in 10 definite columns, the sockets either irregularly
arranged with three under each radial, or in 15 columns of which the central one in each radial
area may be reduced to a single socket
6'. Cirri with more than 40 (40-60 + ) segments; spines on the division series and arm bases coarse,

usually more or less separated; IIBr series, when present, 2.
843803—50 11

154 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

c1. Spines on the elements of the division series and lower brachials confined almost entirely to
the proximal and distal edges; centrodorsal with two converging columns of cirrus sockets
on the outer sides of each radial area, with the central column represented by a single
socket; larger, the 10-12 arms about 175 mm. long and the cirri about 40 mm. long with
60+ segments (Galapagos Islands and off Panama; 598-1,429 meters) ..agassizii (p. 158)
c2. Dorsal surface of the division series and lower brachials studded with stout, well-spaced,
sharply conical spines, the edges of the ossicles everted and crenulate, dentate, or serrate,
but not conspicuously spiny; cirri in 15 crowded columns of 2 or 3 each; smaller, the 10—11
arms 95 mm. long and the cirri 33 mm. long with 40-50 (usually about 50) segments (western

Aleutian Islands; 1,912 meters) villosa (p. 162)

b2. Cirri with less than 40 (seldom more than 35) segments; spines on the division series and arm

bases very fine and, at least along the edges, crowded; IIBr series, when present, 4(3 + 4).
c1. Elements of the division series and arm bases thickly covered dorsally with excessively fine
spines which are often grouped on irregular pedicels suggesting paxillae; larger, the 11
arms 80 mm. long and the cirri 20-25 mm. long with 31-38 (usually about 35) segments

(Nicobar Islands; 1,024 meters) peripolos (p. 178)

c2. Elements of the division series with scattered fine spines, or with finely spinous edges ; smaller,

the arms mostly apparently about 50 mm. long.

d1. Scattered spines on the elements of the division series and arms bases; 25-35 cirrus segments
e1. Spines on the division series and arm bases numerous; 25-30 cirrus segments (Ascension

Island; 768 meters) multispina (p. 180)

e2. Spines on the division series and arm bases few; 35 cirrus segments. (Tristan da Cunha;

1,005 meters) setosa (p. 182)

d1. Elements of the division series and arm bases without spines except along the proximal
and distal edges; brachials with the distal border thickened, forming a transverse crest
that bears only a few very fine spines; 21 cirrus segments (Canary Islands; 1,330-1,340
meters) omissa (p. 184)

THALASSOMETRA BISPINOSA (P. H. Carpenter)

Antedon bispinosa P. H. CABPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 115 (de-
scription; Challenger station 147), pi. 20, figs. 3, 4. — HARTLAUB, Bull. Mus. Comp. Zool., vol.
27, No. 4, 1895, pp. 130, 131 (systematic position; bathymetric relationships), p. 134 (compared
with A. agassizii). — SHIPLEY, Antarctic Manual, 1901, Chapter 18, p. 269. — HAMANN, Bronn's
Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed).— A. H. CLARK,
Crinoids of the Indian Ocean, 1912, p. 33 (identity). — KOEHLER, Echinodermes des mersd' Europe,
vol. 1, 1924, p. 58 (depth).

Thalassometra bispinosa A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Amer. Nat., vol. 42, No. 500, 1908, p. 542 (belongs to a group characteristic of the oceanic area) ;
Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same); Proc. Biol. Soc. Washington, vol. 22, 1909,
p. 14 (listed); Crinoids of the Indian Ocean, 1912, p. 208 (synonymy; locality); Smithsonian
Misc. Coll., vol. 61, No. 15, 1913, p. 47 (published references to the specimen in the B. M.;
Challenger station 147); Journ. Washington Acad. Sci., vol. 5, No. 3, 1915, p. 81 (Antarctic;
range); Die Crinoiden der Antarktis, 1915, p. 105 (collected by the Challenger), p. 107 (in key
to Antarctic crinoids), p. 112 (synonymy; habitat), p. 169 (deep water Antarctic species), p.
170 (range and relationships), p. 192 (further discussion); Unstalked crinoids of the Siboga-
Exped., 1918, p. 166 (in key; range), p. 170 (references). — GISLEN, Ark. Zool., vol. 19, No. 32,
Feb. 20, 1928, p. 7, No. 27 (notes).

Diagnostic features. — The elements of the division series and lower brachials are
bordered with numerous coarse blunt spines, and the eighth and following brachials
each have 2 or 3 long, curved, overlapping spines near the distal edge; the lower pin-
nules are very spiny; and the cirri are arranged hi 10 definite columns on the centro-
dorsal. The 10 arms are about 50 mm. long and the cirri are about 17 mm. long with
30-35 segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 155

Description. — The centrodorsal is almost columnar; according to the figure the
cirrus sockets are arranged in 10 columns with usually two to a column; the columns
seem to be in close apposition all around the centrodorsal.

The cirri are about XXV, 30-35, according to the figure about 17 mm. long. The
three basal segments are almost saucer-shaped and those following become nearly or
quite twice as long as broad, soon becoming shorter again, about half again as broad as
long, and acquiring a marked dorsal keel which becomes reduced to a spine on the later
segments.

The distal edge of the radials is fringed with blunt spines. The IBrt are short
with the proximal and distal borders fringed with blunt spines. The IBr2 (axillaries)
are pentagonal with a curved base, overlapping the IBri laterally. The dorsal surface
of the elements of the IBr series is strongly convex and spinous, and their borders
are fringed with blunt spines. They are strongly flattened laterally against their
neighbors.

The 10 arms are about 50 mm. long. The first brachials are rounded and short in
the median line, but with depressed lateral portions which meet one another by flattened
surfaces all around the calyx. The second brachials are more square and scarcely
project backward into the first. The margins of the lower brachials are fringed with
spines. The eighth and following brachials become quadrate and slightly overlapping,
with two or three large curved spines near the distal edge which become long and prom-
inent in the outer portions of the arms.

Syzygies occur between brachials 3 + 4, again from between brachials 12+13 to
between brachials 15+16, and distally at intervals of 4 or more muscular articulations.

PI is much larger than its immediate successors, with the three or four basal seg-
ments somewhat flattened on the outer side and the second-fifth with the inner edge
slightly keeled and folded upward. P» is but little larger than P2, and the pinnules
following become gradually longer, with overlapping spinous segments.

The disk is 6 mm. in diameter and is strongly plated. The brachial ambulacra
are irregularly plated. The pinnule ambulacra have large covering plates and ill
defined side plates. Sacculi are rare.

The color hi alcohol is white with large dark brown patches on the calyx.

Notes. — The preceding description is adapted from the original description by
Carpenter with a few additions from his figures. Examination of the type specimen
in London showed that this is a well developed and comparatively large species. Gis-
len, who also examined the type specimen, wrote that the cirri are arranged in 10 col-
umns on the centrodorsal. The brachials have stout tubercles only, spines along the
border and in the middle of the synarthrial pairs, and no fine spinosity. He said it is
closely related to Stenometra, to which genus it ought, perhaps, to be referred. The
lesser number of arms than in Stenometra, he said, is- of less importance.

Locality. — Challenger station 147; between Marion Island and the Crozets (lat.
46°16' S., long. 48°27' E.); 2,925 meters; bottom temperature 1.2° C.; diatom ooze;
December 30, 1873 [P. H. Carpenter, 1888; Hartlaub, 1895; Shipley, 1901; A. H.
Clark, 1907, 1908, 1909, 1912, 1913, 1915, 1918; Koehler, 1924; Gislen, 1928] (1, B. M.).

History. — Antedon bispinosa was described and figured by Dr. P. H. Carpenter in
his report on the comatulids of the Challenger expedition published in 1888. In 1895
Dr. Clemens Hartlaub discussed its systematic position and bathymetrical relation-

156 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ships, and compared it with his new species Antedon agassizii. It was listed as Antedon
bispinosa by Sir Arthur E. Shipley in 1901, and by Dr. Otto Hamann in 1907.

In my revision of the genus Antedon published in 1907 bispinosa was transferred
to the new genus Thalassometra. In two papers published in 1908 Thalassometra bis-
pinosa was said to belong to a group characteristic of the oceanic area. In my revision
of the family Thalassometridae published in 1909 it was listed as Thalassometra bispinosa,
and it was included under this name, with the synonymy and range, in my memoir on
the crinoids of the Indian Ocean published in 1912. In a paper on the crinoids of the
British Museum published in 1913 I gave a brief note on the type specimen of Thalas-
sometra bispinosa, and listed it from the Antarctic, with the range, in 1915. In my
memoir on the crinoids of the Antarctic published in 1915 Thalassometra bispinosa was
discussed at considerable length. In my memoir on the unstalked crinoids of the
Siboga expedition published in 1918 bispinosa was included in a key to the species of
Thalassometra and the synonymy and range were given. Prof. Rene Koehler mentioned
this species in 1924, and in 1928 Prof. Torsten Gislen published additional notes on the
type specimen.

THALASSOMETRA ELECTBAE John

Thalassometra, n. sp., A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 51; Crinoids of the Indian
Ocean, 1912, p. 208; Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 70; John Murray Exped.
1933-34, Sci. Reports, vol. 4, No. 4, 1936 (Jan. 1, 1937), p. 101, 104, 105.

Thalassometra electrae JOHN, Ann. Mag. Nat. Hist., ser. 10, vol. 20, August 1937, p. 161.

Diagnostic features. — The elements of the division series and lower brachials are
bordered with numerous coarse blunt spines, and the dorsal surface is studded with
large well spaced tubercles; the proximal pinnules are not spiny; and the cirri are
arranged in 10 definite columns on the centrodorsal. There are 10 arms (all broken
off at the base in the single known specimen), and the cirri are about 28 mm. long with
29^3 (usually about 40) segments.

Description. — The centrodorsal is a fairly high rounded cone. Its edge is produced
into slight interradial corners. The dorsal pole is large and rounded and is beset with
long coarse tubercles. The cirrus sockets are arranged in 10 evenly spaced columns,
2 in each radial area, and there are 2, exceptionally 3, sockets in each column.

The cirri are XXII, 29-^13, usually about 40, about 28 mm. long. The first three
segments are broader than long, the third a little longer than the second, and the
second than the first. The fourth segment is constricted centrally and is about one
and one-third times as long as the least width. The distal edge of each of these four
segments is strongly produced forward and outward to form a cup around the base of
the next; the edge of the cup is denticulate. The fifth-seventh segments are slightly
more than twice as long as broad; on each cirrus one or another of them is a transition
segment with the distal third or quarter white and glossy, like the succeeding segments,
and the proximal part a dull yellow like the preceding segments. Distally the seg-
ments gradually decrease in length, at about the fifteenth becoming as broad as long;
beyond the fifteenth all are slightly broader than long. Toward the end of the cirrus
the segments become progressively smaller. The fifth-seventh segments show the
beginnings of a dorsal spine. This rapidly increases in size. By the ninth-twelfth
segments it is spinelike, arising from the distal fifth of the dorsal edge. It becomes
much stronger distally. About the twentieth-twenty-fifth segment it arises from the

A MONOGRAPH OF THE EXISTING CRINOIDS 157

entire dorsal edge. On these more distal segments its apex is subterminal. The distal
edge of all the segments beyond the fourth is produced into a delicate, transparent,
finely dentate collar which is narrow on the more proximal segments, and wider, es-
pecially on the dorsal side, on the distal segments. The opposing spine arises from nearly
the whole of the dorsal edge of the penultimate segment; it is strong and is directed a
little forward. The terminal claw is strong and curved.

The radials are comparatively long, in the midradial line about one-sixth as long
as broad. Their distal edges are concave. The IBri are four times as broad as long,
narrower distally than proximally, strongly rounded dorsally, widely separated from
each other and not incised by the IBr2. The proximal edge is convex, the distal con-
cave. The IBr2 (axillaries) are a little broader than long with strongly rounded sides.
The proximal edge is gently convex, not angular. The distal edge is produced into
a fairly long projection in the midradial line and is concave on either side of this. One
of the radials bears a long rodlike tubercle, but the others are bare. Large well spaced
tubercles on the division series and lower brachials are the most conspicuous feature of
this animal, even to the naked eye. These tubercles stand out at right angles to the
surface of the ossicles; most of them are rodlike, though some are flattened and blade-
like. Their arrangement has an order that is not at first sight apparent. On the
IBri the middle point of the proximal border is raised into a blunt spine, a low knob, or
a bigger lip. In front of and on either side of it in the proximal half of the ossicle stand
two tubercles. There are usually two or three tubercles laterally, on each of the
rounded sides. In most of the IBr2 the proximal edge is produced outward into two
small triangular lips, one on either side of the middle point; in front of and between
these lips, in the midradial line, is a single strong tubercle. Along either side of the
distal edge there are three to five tubercles. There may be additional lips or there may
be tubercles along the lateral parts of the proximal edge, and there are usually two or
three tubercles on each of the rounded sides. The greater part of the dorsal surface
near the midradial line is free from tubercles.

The first brachials are roughly rectangular, more than half as long as broad, and
are not incised by the second. They carry about five to eight tubercles, some placed
in the proximal half, a few on the proximal edge itself, and the others on the rounded
exterior side. The distal half of the dorsal surface, except for the exterior side, is usu-
ally free from tubercles. The second brachials are irregular in shape, wider distally
than proximally, a little wider than long. The distal and outer edges are straight,
the interior is oblique, and the narrow proximal edge is slightly rounded. The large
tubercles lie along and near the proximal and distal edges, leaving the middle of the
dorsal surface smooth. The hypozygal of the first syzygial pair is about twice as
broad as long. There are large tubercles along the proximal edge, and there may be
smaller tubercles along the distal edge.

P! is the only pinnule present, and only one of these is nearly complete. It is
about 8 mm. long and is composed of 17 segments. The first segment is rounded, about
as long as broad, with the dorsal edge raised distally into a low prominence. The
segments immediately following are broader than long. The second bears two promi-
nences dorsally and distally, one on each side, the inner (nearer the arm) being the larger.
On the third to the fifth or sixth segments both prominences are considerably larger.
The inner arises from the whole of the lateral edge as a high narrow ridge with the same

158 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

long axis as the pinnule; on the fourth and fifth segments its crest may be indented so
that it has two peaks. The outer prominence is not so long or so high; it arises from
the distal third of the dorsolateral edge; its summit is rough with spines. The dorsal
surface between the prominences is flat so that the general appearance of the dorsal
surface of the proximal part of the pinnule is that of a flat-bottomed channel running
between long and high prominences on the inner side and short and lower prominences
on the outer. Between the sixth and ninth segments the long inner prominence de-
creases and becomes obliquely inclined to the dorsal surface, and finally passes into a
lateral extension of it. At the same tune the outer prominence rapidly decreases, to
disappear at about the twelfth segment. The distal segments of the pinnule, as viewed
from above, are broad and flat, considerably broader than long, and broader distally
than proximally, the greater distal width being on the inner side.

The disk is very heavily plated.

Locality.— North-west of Sokotra (lat. 14°20' N., long. 52°30' E.); 2,194 meters
(1,200 fathoms); Capt. V. F. Sparks, cable repair ship Electra, July 1909 [A. H. Clark,
1911, 1912, 1913, 1937; John, 1937] (1, B. M.).

History. — During a visit to the British Museum in 1910 I found this species in a
jar with new species of Pachylometra (Perissometra) and Thaumatometra, and recorded
it as a new species of Thalassometra in 1911, 1912, 1913, and 1937. It was formally
described by D. Dilwyn John in 1937.

THALASSOMETRA AGASSJZII (Harllaub)

[See vol. 1, pt. 2, pi. 3, figs. 981-983, pi. 13, fig. 1050, pi. 14, fig. 1059, pi. 22, fig. 1140, pi. 27, figs.

1171, 1172.]

Antedon agassizii HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, pp. 129, 131 (description
and detailed discussion; Albatross stations 3357, 3408, 3409), pi. 1, figs. 4, 7, 8, pi. 2, figs. 16, 18,
19, pi. 3, fig. 23, pi. 4, fig. 26. — H. L. CLARK, Proc. Washington Acad. Sci., vol. 4, 1902, p. 522. —
HAMANN, Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, pp. 1578, 1580
(listed).

Thalassometra agassizi A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed).

Thalassometra agassizii A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 203 (synonymy; locality);
Unstalked crinoids of the St'boja-Exped., 1918, p. 167 (in key; range), p. 170 (references).

Diagnostic features. — The elements of the division series and lower brachials are
bordered proximally and distally with coarse blunt spines, with occasionally a few on
the dorsal surface; and the cirri are arranged in 10 columns on the centrodorsal, each
radial pair of columns with an additional cirrus between them near the run of the
centrodorsal. The 10-12 arms are about 175 mm. long, and the cirri are about 40
mm. long with 60+ segments.

Description. — The centrodorsal is of moderate size, dome-shaped with a bare dorsal
pole which is beset with small spines. The cirrus sockets are arranged in three columns
in each radial area, the two outer columns, which meet distally, of three, sometimes
two, sockets, the central of one. The radial areas are separated by slight interradial
ridges.

The cirri are XV-XXII, with up to 60 + segments, about 40 mm. long. They are
slender, and in the outer half strongly compressed laterally. The first two segments
are short, the third is longer, the fourth is about as long as the third, and the sixth is

A MONOGRAPH OF THE EXISTING CRINOIDS 159

the longest, reaching 2.5 mm. in length. From this point the length of the segments
rapidly decreases to about the twentieth, which is followed by a series of short segments
which gradually decrease in size. In correlation with the decrease in size, the dorsal
profile of the cirri becomes conspicuously serrate. Many cirri have on the last thirty
segments a prominent spine. The opposing spine is feebly developed.

The radials are just visible. The IBri are short, laterally entirely free, and are
not incised by the axillaries with which they form slight tubercles. The IBra (axillaries)
are rhombic, distally strongly broadened, sometimes in close contact with their neigh-
bors against which they are sharply flattened laterally. The elements of the IBr
series are beset with short blunt spines (in the figure shown chiefly along the edges).
Sometimes IIBr 2 series are present.

The 10-12 rounded and slender arms, which have a very uneven dorsal surface,
are about 175 mm. long. The brachials as far as the second syzygy bear on the prox-
imal and distal ends small blunt spines that stand out vertically from the dorsal surface,
like the elements of the IBr series. The first brachials are moderately short, broadened
in the proximal half and with sharply flattened outer sides which are appressed against
those of the first brachials of the adjacent postradial series. These laterally flattened
sides continue the lateral extensions of the axillaries and with them form an even surface.
The first brachials are interiorly united in the proximal half. The second brachials
are somewhat longer than the first and are distally broadened. Like the first syzygial
pair they are in close contact with the corresponding ossicles of neighboring arms;
since it is toward the ventral side this contact is difficult to see. The second brachials
are separated from the first by a conspicuous synarthry. The seven brachials following
the first syzygial pair are somewhat broader than long, and are centrally constricted.
From about the ninth onward the length increases and the shape becomes more tri-
angular, remaining so until between about the twentieth and thirtieth. From about
the twenty-third brachial (length 2.5 mm.) onward the length again slowly increases.
The triangular brachials are followed by others more trapezoidal in shape, and in the
outer half of the arms the brachials become strongly overlapping. Their distal ends
are strongly produced, and in the outer half of the arms finely spinous. From the
distal ends longitudinal grooves run inward over the distal half of the brachials. The
arms, which are composed of about 130 brachials, gradually decrease in thickness from
the base outward.

Syzygies occur between brachials 3 + 4, again from between brachials 14 + 15 to
between brachials 16 + 17, and distally at intervals of 3 or 4 muscular articulations.

PI is moderately stiff, 9-11 mm. long with 16-18 short smooth segments of which
the first four — especially the first two — are broader than long. The pinnule is broad
and laterally flattened at the base, after about the sixth segment tapering rapidly to a
delicate tip. The segments in the proximal half are smooth, with the pinnule edge on
the side toward the ambulacrum serrate ; the distal segments have finely spinous distal
borders; the second-fifth segments are carinate. The articulation between the earlier
segments is less close than that between the outer segments, a feature more pronounced
in the pinnules following, the basal segments of which have a somewhat different shape.
These are also somewhat flattened, but this flattening comes to an end on the lower
segments of P3, which is rounded. Pa is about 2 mm. shorter than PI and is corre-
spondingly weaker.

160 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

P2 is shorter than P, and has somewhat fewer segments; it is also less stiff and
markedly more slender. As on the pinnules following the component segments have
finely spinous distal ends.

The succeeding pinnules decrease in length, the shortest being 6 mm. long, and
become more slender with longer segments. After the fifteenth brachial the pinnules
again increase in length, reaching a maximum of 23 mm. with 22-23 segments which
are markedly longer than broad except for the first two, especially the first, which is
short, broad, and trapezoidal.

The disk is 9 mm. in diameter, strongly incised and completely plated. The
ambulacral surface of the arms and genital pinnules is prominently plated. Side
plates occur on the pinnules. The sacculi are small and little evident, alternating with
the side plates.

The color in alcohol is uniform greenish yellow, for the most part having been
extracted by the similarly colored liquid.

Notes. — Hartlaub said that a small specimen with 1 1 arms from Albatross station
3408 is noteworthy in having the segments of PI with less smooth distal ends than
usual; they are finely spiny as is the case only with the distal segments in the other
specimens. From station 3408 there is also a smaller specimen with the arms 45 mm.
long, and in addition there are two very small specimens in which the radials are wholly
visible and are beset with blunt, short, erect spines.

Hartlaub said that a noteworthy feature of this new species, in addition to the
variation in the number of arms, is the reduction of the interradial contact surfaces
of the axillaries and first brachials, and the fact that such contact surfaces may be
completely lacking. The IBrj are entirely free laterally, being in contact only through
the lateral extensions of their broadened proximal ends. Between the contact point
of their anterolateral angles and the contact of the lateral angles of the axillaries there
is a considerable open space (water pore) . Hartlaub pointed out that the same feature
seems to occur in Antedon (Thalassometra) multispina, and that Carpenter here re-
garded it as a juvenile feature.

Noteworthy also, according to Hartlaub, is the size of this species which, with an
expanse of 350 mm., exceeds almost all the other species in the Basicurva group. He
said it was surpassed by Antedon (Perissometra) flexilis with an expanse of 550 mm.,
and by A. (P.) robusta with a spread of nearly 500 mm. In giving an expanse of 550
mm. (55 cm.) for A. (P.) flexilis Hartlaub was quoting Dr. P. H. Carpenter, but the
55 cm. given by Carpenter was an error for 35 cm.

Hartlaub remarked that in the spinosity of the IBr series and lower brachials
there is a decided similarity between this species and Antedon (Thalassometra) bi-
spinosa in which, judging from the figures, the elements of the IBr series and lowest
brachials are beset with small blunt spines not only along the edges but also over their
entire surface. In Th. agassizii this ornamentation runs farther out along the arm
and the small quite erect spines are confined to the proximal and distal edges of the
ossicles so that each articulation is marked by two transverse rows of spines.

Regarding the centrodorsal and the articular faces of the radials (see Part 2, pi. 3,
figs. 981-983) Hartlaub said that the cirrus sockets are moderately large and show a
conspicuous articular boss. The ventral surface of the centrodorsal is approximtely
pentagonal, with the five angles somewhat prominent. The dorsal surface of the ra-

A MONOGRAPH OF THE EXISTING CRINOIDS 161

dial pentagon shows traces of a basal star. On the articular faces of the radials the
muscular fossae are of about the same size as the interarticular ligament fossae, and
have a smooth surface.

The ambulacral plating of the pinnules is composed, according to Hartlaub, of
side- and covering-plates. The latter are fine-meshed approximately oval plates.
They rest on the side plates and are apparently movable, since then- position is vari-
able. Sometimes they lie flat like imbricating tiles, and sometimes they are more
raised. If they are viewed from below when in this position it is seen that they have
an alternating oblique position in reference to the longitudinal axis of the arm. Their
precise attachment was not determined by Hartlaub. They are exceedingly small,
very brittle, and difficult to isolate. They are attached by ligaments that are not
broken down by boiling for several minutes in caustic potash, and too long boiling in
caustic destroys them. The side plates are arranged in a zigzag. On each side of
the ambulacral groove they form a sort of Spanish wall. In the niches of this wall,
more or less concealed, lie the sacculi. The produced angles are mostly formed by two
apposed plates; in other places, for instance at the end of a pinnule, they appear to
originate from breaking off from a single plate. The side plates are more wide-meshed
than the covering plates and are often quadrangular with notched edges. In certain
places one sees that through these regularly recurring notches two gaps are formed
in the line of contact of their ends. The higher gap is occupied by a sacculus and
through the lower a tentacle protrudes.

Localities.— Albatross station 3409; Galapagos Islands (lat. 0°18'40" S., long.
90°34'00" W.); 598 meters; bottom temperature 5.7° C.; black sand; April 3, 1891
[Hartlaub, 1895; H. L. Clark, 1902; A. H. Clark, 1907, 1909, 1912, 1918].

Albatross station 3408; Galapagos Islands Gat. 0°12'30" S., long. 90°32'30" W.);
1,250 meters; bottom temperature 4.2° C.; globigerina ooze; April 3, 1891 [Hartlaub,
1895; H. L. Clark, 1902; A. H. Clark, 1907, 1909, 1912, 1918].

Albatross station 3357; off Mariato Point, Panamd (lat. 6°35'00" N., long.
81°44'00" W.); 1,429 meters; bottom temperature 3.6° C.; green sand; February 24,
1891 [Hartlaub, 1895; H. L. Clark, 1902; A. H. Clark, 1907, 1909, 1912, 1918].

Geographical range. — From the Galapagos Islands to Panama.

Bathymetrical range. — From 598 to 1,429 meters.

Thermal range.— From 3.6° to 5.7° C.

History. — Antedon agassizii was described and figured by Dr. Clemens Hartlaub
in 1895 from specimens from Albatross stations 3408 and 3409 in the Galapagos Islands
and station 3357 off Mariato Point, Panama. Hartlaub did not give the number of
specimens he had, but mentioned three from station 3408 that apparently were not
included in the original description. He described and figured the centrodorsal and
radial pentagon, and the side- and covering-plates., and discussed the relationships of
the species in detail. Dr. Hubert Lyman Clark in 1902 listed Antedon agassizii among
the echinodenns known from the Galdpagos Islands.

In my revision of the genus Antedon published in 1907 agassizii was transferred to
the new genus Thalassometra, and in my revision of the family Thalassometridae
published in 1909 it was listed as Thalassometra agassizii. In my memoir on the
crinoids of the Indian Ocean published hi 1912 and again in my report on the unstalked
crinoids of the Siboga expedition published in 1918 Thalassometra agassizii was listed

843803—50 12

162 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and the synonymy and range were given; in the Siboga report agassizii was included
in the key to the species of the genus Thalassometra.

THALASSOMETRA VILLOSA (A. H. Clark)

PLATE 17, FIGURES 50-52

[See also vol. 1, pt. 1, figs. 95, p. 157, 197, 198, p. 237, 272, p. 259, 488, p. 365; pt. 2, figs. 71, p. 43,
323, p. 227, 350, p. 229, 823, p. 392, 879, 880, p. 435.]

Antedon villosa A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 138 (description; Albatross
station 4780).

Thalassomelra villosa A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Amer. Nat., vol. 42, No. 500, 1908, p. 542 (belongs to a group characteristic of the oceanic area);
Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same); Proc. Biol. Soc. Washington, vol. 22, 1909,
p. 14 (listed); Crinoids of the Indian Ocean, 1912, p. 203 (synonymy; locality); Unstalked crinoids
of the Siboga-'Exped., 1918, p. 167 (in key; range), p. 170 (references).

Diagnostic features. — The dorsal surface of the elements of the division series and
lower brachials is studded with stout, well-spaced, sharply conical spines, and their
borders are everted and crenulate, dentate, or serrate, but not conspicuously spiny;
and the cirri are arranged in 15 crowded columns of 2 or 3 each on a rather large centro-
dorsal. The 10 or 11 arms are 95 mm. long, and the cirri are 33 mm. long with 40-50
(usually about 50) segments.

Description. — The centrodorsal is rather large, bluntly conical or more or less
hemispherical, with the cirrus sockets in 15 crowded columns, 1, 2, or 3 to a column.

The cirri are XV-XLV (usually about XL), 40-50 (usually about 50), about 33 mm.
long. The first three segments are short, the fourth is about as long as broad, and the
following to the thirteenth or fourteenth are longer than broad, the seventh, which is the
longest, being somewhat over twice as long as broad; distally the segments gradually
become shorter. The earlier segments have then- distal ends abruptly turned outward,
while from about the tenth onward small blunt dorsal spines are developed which,
however, never become especially prominent. The seventh is a transition segment
with the proximal three-quarters of its surface dark in color and dull like that of the
preceding segments, and the distal quarter lighter and more highly polished like the
surface of the segments succeeding.

The disk is well plated, as are the brachial and pinnule ambulacra. The sacculi
are small but numerous.

The ends of the basal rays are visible as small tubercles in the interradial angles
of the calyx.

The radials are barely visible, crescentic in shape. The IBrt are short, about 3
times as broad as long. The IBr2 are broadly pentagonal, broader than long; there is
a rounded synarthrial tubercle on the articulation between these elements. The
IIBr series are 2, resembling the IBr series but proportionately somewhat longer.

Arms 10, in one case 11, in number, 95 mm. long. The first 8 or 9 brachials are
oblong, broader than long, with the edges strongly everted and bluntly spinous, the
following very obliquely wedge-shaped, about as long as broad, with the distal edges
somewhat produced, becoming more elongate distally with the distal edges overlapping
and spinous and the dorsal surface finely striate. The elements of the IBr series (and
of the IIBr series when present) and the first 2 brachials are bordered with a row of

A MONOGRAPH OF THE EXISTING CRENOIDS 163

short spines or prominent tubercles, and their dorsal surface is thickly studded with
spines; they are sharply flattened laterally and are in close lateral apposition.

Syzygies occur between brachials 3+4, again from between brachials 17+18 to
between brachials 19 + 20, and distally at intervals of from 4 to 9 muscular articulations.

PI is 10 mm. long, enormously stout, tapering from the base to the tip, more rapidly
in the distal portion, and is composed of 20 segments. P2 is 7 mm. long with 15 seg-
ments, much more slender than PI. The following pinnules are somewhat shorter,
but increase again distally to 14 mm. The distal pinnules have the first segment
short, broadly trapezoidal, the second trapezoidal but longer, the following to the
middle of the pinnule about as long as broad, and the remainder elongate. All the
pinnule segments have prominently everted spiny distal edges.

Locality. — Albatross station 4780; off Agattu Island, western Aleutians (lat.
52°01'00" N., long. 174°39'00" E.); 1,912 meters; bottom temperature 2.2° C.; gray
mud, sand, and pebbles; June 7, 1906 [A. H. Clark, 1907, 1908, 1909, 1912, 1918]
(5, U.S.N.M., 22630 [type], 35584, 36174).

History. — This species was described as Antedon villosa in 1907 from five specimens
that had been dredged by the Albatross at station 4780, at the western end of the Aleu-
tian Island chain, in the preceding year. In my revision of the genus Antedon published
later in 1907 Antedon villosa was made the type of the new genus Thalassometra. In
two papers published in 1908 Thalassometra villosa was said to belong to a group char-
acteristic of the oceanic area. In my revision of the family Thalassometridae published
in 1909 Thalassometra villosa was listed. In my memoir on the crinoids of the Indian
Ocean published in 1912 and in my report on the unstalked crinoids of the Siboga
expedition published in 1918 Thalassometra villosa was listed and the synonymy and
locality were given; hi the Siboga report villosa was included in the key to the species
of the genus Thalassometra.

THALASSOMETRA ATTENUATA A. H. Clark

PLATE 17, FIGURES 53, 54
[See also vol. 1, pt. 2, figs. 523, 524, 527, 528, p. 283.]

Thalassometra attenuata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 147 (description;
22°24' 00" N., 66°51' 30" E.; 765 fathoms); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 553 (com-
pared with Th. hirsuta); Crinoids of the Indian Ocean, 1912, p. 204 (synonymy; detailed
description; locality), fig. 38, p. 205; Smithsonian Misc. Coll., vol. 60, No. 15, 1913, p. 46 (com-
pared with Th. pergracilis [gracilis]); Unstalked crinoids of the Siboga-Exped., 1918, p. 168 (in
key; range), p. 171 (references); Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 654 (off
Mozambique; 500 fathoms). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11,
1934, p. 22.— A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936
(Jan. 1, 1937), p. 87 (listed), p. 93 (Mabahiss station 143; notes; range), pp. 101, 104.

Diagnostic features. — The elements of the division series and lower brachials are
smooth dorsally, or bear a few low inconspicuous tubercles; the synarthrial tubercles
are rather prominent, but there is no median carination; and the cirri are arranged in
10 definite columns on the centrodorsal. The 10-13 arms are 80-120 mm. long, and
the cirri are 50 mm. long with 62-71 segments.

Description. — The centrodorsal is conical with the sides slightly convex, 3 mm.
broad at the base and 2 mm. high. The cirrus sockets are arranged in 10 columns

164 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

of usually 2 each, the radial pairs of columns being usually slightly separated in the
midradial line by a shallow furrow or a coarsely tubercular ridge.

The cirri are XX, 62-71, 50 mm. long, elongated and very slender. The longest
proximal segments are twice as long as broad or slightly longer, and the twenty-fifth
and following are slightly broader than long. The segments after the seventeenth-
twentieth have the distal dorsal edge produced into a serrate ridge that soon gives
place to small carinate dorsal spines.

The ends of the basal rays are visible as small, though rather prominent, tubercles
hi the interradial angles.

The radials are entirely concealed by the centrodorsal, or are just visible beyond
its run, sometimes bearing on the dorsal surface a row of small tubercles. The IBri
are very short, widely chevron-shaped, with the proximal edge and the lateral thirds
of the distal edge somewhat everted, and the distal lateral angles more or less produced.
The IBr2 (axillaries) are triangular, twice as broad as long with the anterior edges
somewhat everted and the lateral angles more or less produced. The IIBr series,
when present, are 4(3+4); they are developed in two of the six specimens hi the type
series. The elements of the IBr series and first two brachials are smooth dorsally or
bear a few low inconspicuous tubercles ; then- lateral borders are usually slightly spinous ;
the synarthrial tubercles are rather prominent. The lateral edges of the elements of
the IIBr series are more or less produced.

The 10-13 arms are from 80 to 90 mm. long. They are exceedingly slender, hav-
ing in general more the appearance of the arms of some slender antedonid than of those
of a thalassometrid. The first brachials are short, wedge-shaped, twice as long ex-
teriorly as ulteriorly, basally united ulteriorly, with the anterior and posterior edges
slightly thickened, the lateral edges somewhat produced, and the anterolateral angles,
both interior and exterior, more or less produced. The second brachials are similar in
size and shape. The first syzygial pah- (composed of brachials 3 + 4) is usually slightly
longer ulteriorly than exteriorly, from half again to about as broad as long. The next
three or four brachials are approximately oblong, twice as broad as long, and those
following become triangular, as long as broad, distally slowly increasing hi length and
becoming wedge-shaped, being twice as long as broad in the outer part of the arms.
The brachials beyond the second have the dorsal surface studded with very fine short
spines or sharp tubercles which hi some individuals are nearly obsolete. At about the
end of the proximal fourth of the arm the brachials begin to develop prominent longi-
tudinal striations which increase in frequency and in height distally. The proximal
oblong brachials have the proximal and distal ends somewhat prominent. After about
the twentieth brachial the distal edges begin to overlap, and in the distal portion of the
arms the brachials have the distal part somewhat expanded and the central part some-
what constricted so that the outer portions of the arms closely resemble those of the
species of Antedonidae.

The pinnules are essentially as hi the related species; the three lowest pinnules on
either side of the arm are very strongly carinate.

The color hi alcohol is white, the perisome, and sometimes the IBr series and arm
bases, light brownish.

Notes. — The arms of the specimen from Mabahiss station 143 were probably about
120 mm. long. The cirri are about 45 mm. long and consist of 55 segments of which

A MONOGRAPH OF THE EXISTING CRINOIDS 165

the ninth is a transition segment. The interradial pairs of columns of cirrus segments
are narrow and are widely separated by a broad midradial deeply concave bare area.

Localities. — Investigator; south of Kurrachi (lat. 22°24'00" N., long. 66°51'30" E.);
1,398 meters; bottom temperature 6.0° C.; green mud [A. H. Clark, 1909, 1911, 1912,
1913, 1918, 1937; Gislen, 1934] (6, U.S.N.M., 35591; I. M.).

Mabahiss station 143; in the vicinity of the Maldive Islands (from lat. 5°15'48" N.,
long. 73°22'48" E. to lat. 5°13'42" N., long. 73°23'36" E.); 797 meters; temperature
(at 770 meters) 7.88° C.; gray sand; March 30, 1934 [A. H. Clark, 1937] (1, B. M.).

Off Mozambique (lat. 16°48' S., long. 39°40' E.); 914 meters; from a cable; cable
repair ship Lady Denison-Pender, Eastern and Associated Telegraph Co. [A. H. Clark,
1929] (1, B. M.).

Geographical range. — From off Kurrachi to the Maldive Islands and southwestward
to the coast of Mozambique.

Bathymetrical range. — From 797 to 1,398 meters.

Thermal range.— From 6.0° to about 7.88° C.

History. — Thalassometra attenuata was described in 1909 from 6 specimens dredged
off Kurrachi in 765 fathoms by the Royal Indian Marine Survey steamer Investigator.
In 1911 it was compared with the new species Th. hirsuta, and in 1912 in my memoir
on the crinoids of the Indian Ocean it was redescribed and figured. In 1913 I compared
it with the type series of Carpenter's Antedon gracilis. In my memoir on the un-
stalked crinoids of the Siboga expedition published in 1918 attenuata was included in
the key to the species of Thalassometra and the synonymy and range were given. In
1929 I recorded a specimen from off Mozambique in 500 fathoms that had been taken
from a cable brought to the surface by the cable repair ship Lady Denison-Pender of
the Eastern and Associated Telegraph Co. In 1934 Prof. Torsten Gislen discussed
certain features of the structure. In 1936 I recorded and gave notes on a specimen
from the John Murray Expedition to the Indian Ocean, 1933-34, that had been dredged
by His Egyptian Majesty's steamer Mabahiss at station 143 in the Maldive region in
797 meters.

THALASSOMETRA HIRSUTA A. H. Clark

PLATE 18, FIGURE 59

Thalassometra hirsuta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 552 (description; Alba-
tross station 5445; also stations 5275, 5474); Zool. Anz., vol. 39, No. 11/12, 1912, p. 426 (com-
pared with Th. margaritifera) ; Crinoids of the Indian Ocean, 1912, p. 206 (synonymy; range);
Unstalked crinoids of the Siboga-'Exped., 1918, p. 168 (in key; range), p. 169 (references; notes;
stations 85, 286), pp. 272, 275 (listed). — GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928,
p. 7 (probably the same as Th. gracilis and Th. pubescent).

Diagnostic features. — The elements of the division series and lower brachials have
the edges all around strongly everted and coarsely spinous, with a coarsely spinous
median carination and a few coarse spines scattered over the dorsal surface; and the
cirri are arranged in 10 definite columns on the centrodorsal. There are 10 arms,
and the cirri are 30-45 mm. long with 48-66 (usually 54-66) segments.

Description. — The centrodorsal is low-conical, with the dorsal pole finely papillose.
The cirrus sockets are arranged in 10 columns of two or three each, the two columns in
each radial area being slightly separated proximally by a narrowly linear or wedge-
shaped papillose area.

The cirri are slender, XV-XXV, 48-66 (usually 54-66), from 30 to 50 mm. long.
The first segment is short, those following increasing in length and becoming about as

166 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

long as, or slightly longer than, broad on the fourth; the fifth or sixth is a transition
segment, about three times as long as broad. The segment following is nearly as long,
those succeeding gradually decreasing in length, those in the distal portion of the cirri
being somewhat broader than long. After the transition segment the distal dorsal
edge slowly becomes produced, the short outer segments bearing rather low blunt
spines.

The radials are concealed by the centrodorsal. The IBrj are very narrow and
crescentic with the edges all around strongly everted and coarsely spinous, with a
coarsely spinous median carination, and a few coarse spines scattered over the dorsal
surface. The IBr2 (axillaries) are rhombic, twice as broad as long, with the edges all
around strongly everted and coarsely spinous, with a coarsely spinous median carina-
tion in the proximal two-thirds, and with coarse spines scattered irregularly over the
dorsal surface.

There are 10 arms. The first brachials are short, slightly wedge-shaped, three or
four times as broad as long exteriorly, with the edges all around strongly everted and
coarsely spinous, the dorsal surface more or less covered with rather long spines, and
with a coarsely spinous median keel. The second brachials are slightly larger and
more obliquely wedge-shaped. The first syzygial pair (composed of brachials 3 + 4)
is oblong, from half again to nearly twice as broad as long. The following four brachials
are approximately oblong, twice as broad as long, those succeeding becoming triangular,
as long as broad, and farther out wedge-shaped and somewhat longer than broad, and
elongate terminally. The third-eighth brachials have strongly everted and spinous
ends, and the dorsal surface very thickly covered with rather long fine spines; the
median carination seen on the elements of the IBr series and on the first two brachials
may be faintly suggested on the third and fourth, but extends no farther. As the
brachials become triangular the dorsal spinosity becomes shorter and finer and less
evident, the proximal ends of the brachials become less everted and the distal more so,
this distal eversion, leaning gradually forward, becoming a spinous overlap, which is
fairly prominent distally. At the same time the dorsal surface of the brachials becomes
marked by numerous fine, sharp, longitudinal ridges, most prominent distally. In the
outer part of the arm the distal part of these ridges breaks up into numerous thickly
set anteriorly directed spines.

Notes. — A specimen from Siboga station 85 may be described as follows: The
centrodorsal is small, low, rounded conical; the dorsal pole is thickly studded with
small more or less sharpened papillae. The cirrus sockets are arranged in 10 closely
crowded columns of two sockets each.

The cirri are XX, 60-64, from 40 to 45 mm. long. The longest proximal cirrus
segments are from two-and-one-half to three times as long as broad; the eversion of
the distal edges of the segments begins on the fifth or sixth.

The dorsal surface of the ossicles of the IBr series and first two brachials is uni-
formly and rather thickly covered with short fine spines, and their proximal and distal
edges are everted and armed with very numerous fine spines, which are more closely
set and longer than those on the dorsal surface. The IBri and the proximal half of the
IBr2 (axillary) bear a moderately sharp, though low, median keel which is studded
with slender spines; more or less complete reduplications of this keel occur on the first
two brachials. Beyond the first syzygy the spines become finer, shorter, more thickly

A MONOGRAPH OF THE EXISTING CRINOIDS 167

set, and more evenly distributed, gradually giving way to finely serrate longitudinal
striations as the ends of the brachials become oblique.

The base of the animal is moderately compact, the outer edges of the elements of
the IBr series and lower brachials being straight and in close apposition. Rather small
water pores are present.

The specimen from Siboga station 286 is slightly smaller and more slender than the
preceding, with the spinosity of the IBr series and first two brachials very slightly
finer and thicker. The arms are 80 mm. long, and the cirri are 27 mm. long with 44-51
segments.

In the original description I said that this form is nearest Thalassometra attenuata,
but it is stouter than that species with shorter and somewhat stouter cirri which usually
have fewer segments. It differs markedly, however, in the great development of spines
on the division series and arm bases, these parts in Th. attenuata being comparatively
smooth.

Gislen suggested that hirsuta is probably synonymous with gracilis and pubescens.

Localities. — Albatross station 5474; China Sea, in the vicinity of southern Luzon;
Malavatuan Island (N.) bearing S. 73°30' E., 17.5 miles distant (lat. 13°57'30" N.,
long. 120°03'25" E.); 960 meters; bottom temperature 5.1° C.; gray mud and sand;
July 16, 1908 [A. H. Clark, 1911, 1912, 1918; Gislen, 1928] (1, U.S.N.M., 35587).

Albatross station 5275; China Sea in the vicinity of southern Luzon; Malavatuan
Island (N.) bearing S. 71° E., 10.75 miles distant (lat. 13°55'55" N., long. 120°10'15"
E.); 214 meters; fine sand; July 16, 1908 [A. H. Clark, 1911, 1912, 1918; Gislen, 1928]
(1, U.S.N.M., 35589).

Albatross station 5445; east coast of Luzon; Atalaya Point, Batag Island, bearing
S. 56° E., 5.3 miles distant (lat. 12°44'42" N., long. 124°59'30" E.); 700 meters; bot-
tom temperature 6.8° C.; green mud and sand; June 3, 1909 [A. H. Clark, 1911, 1912,
1918; Gislen, 1928] (4, U.S.N.M., 27500 [type], 35588).

Siboga station 85; Makassar Strait (lat. 0°36'30" S., long. 119°29'30" E.); 724
meters; fine gray mud; June 17, 1899 [A. H. Clark, 1918] (7, U.S.N.M., E. 407; Amster-
dam Mus.).

Siboga station 286; Timor Sea (lat. 8°50'12" S., long. 127°02'12" E.); 883 meters;
mud, evidently a thin layer; January 19, 1900 [A. H. Clark, 1918] (1, Amsterdam Mus.).

Geographical range. — From the Timor Sea northward to Luzon, Philippine Islands.

Bathymetrical range. — From 214 to 960 meters; the average of 5 records is 696
meters.

Thermal range.— From 5.1° to 6.8° C.

Bottom. — Mud, mud and sand, or fine sand.

History. — -Thalassometra hirsuta was described in 1911 from a specimen from
Albatross station 5445; at the same time three other specimens were recorded from this
station, and one each from stations 5275 and 5474. In my memoir on the crinoids
of the Indian Ocean published in 1912 this species was listed and the range and
synonymy were given. In my memoir on the recent crinoids of the Siboga expedition
published in 1918 seven specimens were recorded from station 85 and one from station
286 and notes on these were given. In 1928 Prof. Torsten Gislen suggested that
hirsuta might be a synonym of Carpenter's Antedon gracilis.

168 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

THALASSOMETRA MARGARITIFERA A. H. Clark

PLATE 17, FIGURE 55

Thalassometra margaritifera A. H. CLARK, Zool. Anz., vol. 39, No. 11/12, 1912, p. 426 (description;
Siboga station 45); Unstalked crinoids of the Sihoja-Exped., 1918, p. 169 (in key; range; refer-
ences; description; station 45), p. 271 (listed), pi. 22, fig. 58.

Diagnostic features . — The elements of the division series and lower brachials have
the edges less strongly everted than in Th. hirsuta with the spinosity coarser, the spines
more uniform in size and more thickly distributed over the dorsal surface of the ossicles,
also larger so that there is less difference between the spines of the dorsal surface and
those of the everted edges; the median carination is more rounded and is studded with
spines resembling those of the dorsal surface; and the cirri are arranged in 10 definite
columns on the centrodorsal. The 10 arms are about 95 mm. long, and the cirri
are 45 mm. long with 57+ segments.

Description. — The cirri are about 45 mm. long with somewhat more than 57
segments.

The 10 arms are about 95 mm. long.

This species is very closely related to Th. hirsuta. The eversion of the proximal
and distal edges of the elements of the IBr series and of the first two brachials is less
marked than in Th. hirsuta, and the spinosity is coarser, the spines being more uniform
in size and more thickly distributed over the dorsal surface of the segments; they are
also longer so that there is less difference between the spines of the dorsal surface and
those of the everted edges. The median carination is more rounded than that of Th.
hirsuta, and is studded with spines resembling those of the general dorsal surface.

Locality. — Siboga station 45; eastern Flores Sea, north of the eastern end of Sum-
bawa (lat. 7°24'00" S., long. 118°15'12" E.); 794 meters; fine gray mud with some
radiolarians; April 6, 1899 [A. H. Clark, 1912, 1918] (2, Amsterdam Mus.).

History. — Thalassometra margaritifera was described in 1912 from two specimens
dredged by the Siboga at station 45, and was redescribed and figured in 1918.

THALASSOMETRA MARG1NATA A. H. Clark

[See vol. 1, pt. 1, fig. 96, p. 159.]

Thalassometra marginata A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 206 (detailed de-
scription; Investigator station 218); Unstalked crinoids of the Siboga-Exped., 1918, p. 167 (in
key; range), p. 170 (references); Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 654
(Nicobar Islands; notes).

Diagnostic features. — The elements of the division series and first two brachials
have the proximal and distal edges prominently everted and irregularly and coarsely
dentate, the dentations with numerous fine spines on their tips, and the lateral borders
perfectly plain, without spines or tubercles, and sharply, though narrowly, flattened
against their neighbors; and the cirri are arranged in 10 definite columns on the centro-
dorsal. There are 10 arms, and the cirri are 40 mm. long with 34-46 segments.

Description. — The centrodorsal is truncated conical with the sides slightly convex,
3.5 mm. broad at the base, 1.5 mm. broad at the dorsal pole, and 2.5 mm. long inter-
radially; the dorsal pole is covered with long coarse tubercles. The cirrus sockets
are arranged in 10 columns of 2 each which are in close lateral contact interradially
but are separated in the midradial line by an irregularly wedge-shaped smooth area

A MONOGRAPH OF THE EXISTING CRINOIDS 169

which at its base (proximally) is not quite so wide as a single cirrus socket, from this
point gradually narrowing and disappearing between the distal sockets, which are
nearly or quite in apposition.

The cirri are XX, 34-46, about 40 mm. long, and moderately stout. The longest
proximal segment is from two to two and one-half tunes as long as broad; the sixth
or seventh is a transition segment.

The ends of the basal rays are visible in the interradial angles. Shallow and broad
subradial clefts are present.

The IBr] are short, about four and one half times as broad as long, with the proxi-
mal and distal edges prominently everted and armed with about 6 or 8 irregular coarse
dentations which have numerous fine spines at their tips. The IBr2 (axillaries) are
roughly rhombic with the lateral angles truncated and all the sides concave; the lateral
edges are nearly as long as those of the IBr^ the proximal and distal edges are everted,
the proximal resembling the distal edges of the IBri, the distal with a more regular
finely spinous margin. The elements of the IBr series are hi close lateral apposition
and sharply, though narrowly, flattened against their neighbors; their lateral edges
are perfectly plain, without spines or tubercles.

The 10 arms are all broken off at the first syzygy between brachials 3 + 4. In
shape the brachials resemble those of other species of the genus. They are perfectly
smooth, with no trace of spines or of median carination. The proximal and distal
edges are slightly thickened and everted, with a few small spines or tubercles.

Notes. — The preceding description is based upon a single very fragmentary speci-
men from Investigator station 218. This species is related to Th. hawaiiensis and to
Th. hirsuta. From the former it differs in the much smaller centrodorsal, in the smaller
number of cirrus segments of which the proximal are much longer, in the shorter ossicles
of the IBr series which are hi close lateral contact without intervening interradial water
pores, and hi the eversion of the edges of the ossicles of the IBr series and of the earlier
brachials, these in Th. hawaiiensis being armed with large coarse blunt scattered
spines, though not as a whole turned outward. There are no spines on the dorsal
surface of the ossicles in Th. marginata such as occur, though sparingly, in Th. hawaii-
ensis. From Th. hirsuta this species differs in the very large and coarse instead of
fine tubercles on the dorsal pole of the centrodorsal, in the smoothness of the wedge-
shaped area separating the columns of cirrus sockets proximally, in the fewer cirrus
segments of which the longest are somewhat shorter, in the much less, and more coarsely,
spinous edges of the ossicles, and hi the entire absence of a median carination and of
spines on the dorsal surface of the elements of the IBr series and lower brachials.

The specimen from the Nicobar Islands is young with 10 arms 35 mm. long.

Localities. — Investigator station 218; Maldive Islands; 384 meters [A. H. Clark,
1912, 1918] (1, I. M.).

Nicobar Islands (lat. 7°52'38" N., long. 92°59'13" E.); cable repair ship Patrol,
Eastern and Associated Telegraph Co. [A. H. Clark, 1929] (1, B. M.).

History. — Thalassometra marginata was first described in my memoir on the
crinoids of the Indian Ocean published in 1912 on the basis of a much mutilated indi-
vidual that had been dredged by the Royal Indian Marine Survey steamer Investigator
among the Maldive Islands in 210 fathoms. In my memoir on the unstalked crinoids
of the Siboga expedition published hi 1918 tlus species was included hi the key to the

170 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

species of Thalassometra, and the synonymy and range were given. In 1929 I recorded
a small specimen that had been found on a cable brought to the surface from an unre-
corded depth by the cable repair ship Patrol, of the Eastern and Associated Telegraph Co.

THALASSOMETRA HAWAIIENSIS (A. H. Clark)

[See vol. 1, pt. 1, figs. 195, 196, p. 237; pt. 2, fig. 223, p. 175.]

Antedon hawaiiensis A, H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 152 (description; Albatross

station 3475).
Thalassometra hawaiiensis A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);

Proc. TJ. S. Nat. Mus., vol. 34, 1908, p. 222 (Albatross stations 3475, 3476); Proc. Biol. Soc.

Washington, vol. 22, 1909, p. 14 (listed); Crinoids of the Indian Ocean, 1912, p. 203 (locality);

Die Crinoiden der Antarktis, 1915, p. 124 (shows characteristic features of Anthometra adriani) ;

Unstalked crinoids of the Si&oja-Exped., 1918, p. 168 (in key; range), p. 170 (references) ; Bernice

P. Bishop Mus. Bull. 195, 1949, p. 74 (Albatross stations 3475, 3476), p. 87 (station data).

Diagnostic features. — The elements of the division series and first two brachials are
bordered with thickly set spines; the triangular proximal brachials have projecting
distal edges which increase hi prominence distally, in the distal third of the arms
becoming long curved overlapping spines; and the cirri are arranged in 10 definite
columns on the centrodorsal. The 10-12 (usually 10) arms are 110 mm. long, and the
cirri are 32 mm. long with 50-55 segments.

Description. — The centrodorsal is large, hemispherical or short columnar. The
cirrus sockets are arranged in 10 columns of 1 or 2 each, and the columns are segregated
into 5 radial pairs, each pair being separated from its neighbors on either side by a
shallow groove, which is about as broad as the transverse diameter of a cirrus socket.

The cirri are XX, 50-55, 32 mm. in length. The first 3 segments are short, the
fourth is about as long as broad, and those following increase in length to the seventh,
which is the longest, about twice as long as broad. The succeeding segments decrease in
length, becoming broader than long after the thirteenth and very short distally. Cari-
nate dorsal spines begin to appear at about the tenth segment, and become very prom-
inent distally. The first six segments and the proximal three-quarters of the seventh
are dull yellowish, with a dull surface ; the distal quarter of the seventh and the succeed-
ing segments are white and highly polished. In lateral view the cirri taper gradually
from the base to the middle of the seventh segment, remaining uniform in width from
that point onward.

The disk, brachial and pinnule ambulacra are bordered with remarkably well
developed plates. Sacculi are fairly well developed.

The ends of the basal rays are visible as small tubercles in the interradial angles of
the calyx.

The radials are just visible beyond the rim of the centrodorsal, appearing crescentic
hi shape. The IBri are more than twice as broad as long, with the distal border incised
by the rounded proximal extension of the axillary. The IBr2 (axillaries) are rhombic
about half again as broad as long. The junction between the two elements of the IBr
series rises into a slight tubercle. The IIBr series, when present, are 4(3+4). The
IBri, IIBrj and first two brachials are bordered all around with thickly set spines. The
division series and proximal brachials are in close lateral apposition and are sharply
flattened laterally.

A MONOGRAPH OF THE EXISTING CRINOIDS 171

The arms arc 10-12 (usually 10) in number, 110 mm. in length. The first 6 brachials
are oblong, broader than long, and those following are triangular, about as long as broad,
becoming wedge-shaped and longer distally. The triangular lower brachials have
projecting distal edges which increase in prominence distally, becoming in the distal
third of the arm long curved overlapping spines.

Syzygies occur between brachials 3 + 4, again at about brachials 21 + 22, and
distally at intervals of from 3 to 5 muscular articulations. Following a IIBr series
brachials 1 + 2 are united by syzygy.

P! is 6 mm. long, very stout basally but tapering rapidly after the seventh or
eighth segment, strongly prismatic, sharply flattened exteriorly, and often more or less
carinate. It is composed of about 12 segments which are very short basally, but become
longer than broad terminally. P2 and the foUowing pinnules are shorter and much more
slender, and are composed of fewer segments, which are somewhat longer than broad.
The distal pinnules are about 10 mm. long, slender, the first 2 segments expanded and
trapezoidal, the remainder about twice as long as broad, becoming more elongate
distally.

The color in alcohol is white, with the division series and the first 2 brachials
dark brown.

Localities. — Albatross station 3475; off Oahu, Hawaiian Islands (lat. 21°08'00"
N., long. 157°43'00" W.); 642 meters; fine white sand; December 6, 1891 [A. H. Clark,
1907, 1908, 1909, 1912, 1915, 1918] (3, U.S.N.M., 22653, 35586)

Albatross station 3476; off Oahu, Hawaiian Islands (lat. 21'09'00" N., long.
157°53'00" W.); 545 meters; fine white sand; December 6, 1891 [A. H. Clark, 1908,
1909, 1912, 1915, 1918] (1, U.S.N.M., 35585).

History. — This species is as yet known only from the four specimens collected by
the Albatross in 1891.

THALASSOMETRA LATIPINNA (P. H. Carpenter)

Antedon latipinna P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 116 (descrip-
tion; Challenger station 232), pi. 10, fig. 3. — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4,
1895, p. 131 (systematic and bathymetrical relationships). — A. H. CLARK, Proc. U. S. Nat. Mus.,
vol. 33, 1907, p. 129 (comparison, in key, with A. pvbescens). — HAMANN, Bronn's Klassen und
Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Proc. Biol. Soc.
Washington, vol. 22, 1909, p. 18 (not placed in a revision of the Thlassometridae) ; Crinoids of the
Indian Ocean, 1912, p. 33 (of P. H. Carpenter, 1888= Thalassometra lalipinna).

Thalassomelra latipinna A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Proc. U. S. Nat. Mua., vol. 34, 1908, p. 318 (Japan); Crinoids of the Indian Ocean, 1912, p. 208
(synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 46 (published reference
to specimen in the B. M.; Challenger station 232; characters of the division series and lower
brachials); Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese speciea;
range and its significance); Unstalked crinoids of the iSi&oj/a-Exped., 1918, p. 167 (in key; range),
p. 170 (references).

Diagnostic features. — The elements of the division series and first two brachials
have the edges finely spinous; the distal edges of the brachials are not produced; and
the cirri are arranged in 10 definite columns on the centrodorsal. The 10 arms are 40
mm. long, and the cirri are 30 mm. long with 40 segments.

Description. — The centrodorsal is truncated conical, about 3 mm. broad at the base,
1.7 mm. across the flat dorsal pole, and 3 mm. high. The cirrus sockets are arranged
in 10 apparently evenly spaced columns of 2 each.

172 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XX, 40 ; the longest proximal cirrus segments are nearly twice as long
as broad, and those in the distal half of the cirri are broader than long and overlap
dorsally so as to develop a sharp spinous keel.

The radials are partially visible as narrow bands beyond the rim of the centrodorsal.
The IBri are short and oblong, rather convex in the middle of the dorsal surface. The
IBr2 (axillaries) are rhombic, with the lateral angles truncated so as to form sides nearly
as long as the sides of the IBri, and are about twice as broad as long. The elements
of the IBr series, the first two brachials, and the hypozygal of the first syzygial pair
have straight lateral edges, and small portions of their outer sides are flattened. The
edges of the elements of the IBr series are finely spinous.

The 10 arms are probably about 40 mm. long and are composed of short quadrate
brachials which, as far as they are preserved, are finely spinous on the dorsal surf ace.

Syzygies occur between brachials 3 + 4 and 13+14 and distally at intervals of
8-10 muscular articulations.

P! is short and stout with about 15 segments of which the lowest are short, wide,
and slightly carinate, but not flattened laterally. The pinnules following diminish in
size to about the third pan- (P3 and Pc) and then gradually increase in length, the seg-
ments becoming elongated.

The disk is about 4 mm. in diameter and is much incised and well plated. Side
plates are fairly distinct on the pinnule ambulacra. Sacculi are apparently absent.

The color in alcohol is light brownish white.

The preceding description is adapted from the original description by Carpenter
with a few additions from his figure and from notes which I made after an examination
of the type specimen in London.

Locality.— Challenger station 232; Sagami Bay, Japan (lat. 35°11' N., long. 139°28'
E.); 631 meters; bottom temperature 5.0° C.; green mud; May 12, 1875 [P. H. Car-
penter, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1908, 1909, 1912, 1913, 1915, 1918]
(1,B. M.).

History. — In his report on the comatulids of the Challenger expedition published
hi 1888 Dr. P. H. Carpenter described and figured this species under the name Antedon
latipinna on the basis of a single mutilated specimen from station 232 in 345 fathoms.
In 1895 Dr. Clemens Hartlaub discussed the systematic and bathymetrical relationships
of Antedon latipinna, and in 1907 I compared it, by insertion in a key, with a new
species, A. pubescens.

In my revision of the genus Antedon published later in 1907 latipinna was referred
to the new genus Thalassometra, and in 1908 Tlialassometra latipinna was listed as one
of the crinoids of Japan. In my revision of the family Thalassometridae published in
1909 Antedon latipinna was listed among the species I was unable to place satisfactorily.
In my memoir on the crinoids of the Indian Ocean published in 1912 Thalassometra
latipinna was listed and the synonymy and range were given. In 1913 I published a
note on the type specimen which I had examined at the British Museum in 1910, and
in 1915 I discussed the range and its significance. In my memoir on the unstalked
crinoids of the Siboga expedition published in 1918 latipinna was included in a key to
the species of Thalassometra, and the synonymy and range were given.

A MONOGRAPH OF THE EXISTING CRINOIDS 173

THALASSOMETRA GRACILIS (P. H. Carpenter)

[See vol. 1, pt. 1, fig. 363, p. 297; pt. 2, figs. 224, p. 177, 317, p. 227, 338, p. 229.]

Anledon gracilis P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 107 (descrip-
tion; Challenger station 214), pi. 12, figs. 3-5, pi. 15, figs. 1-4. — HARTLABB, Bull. Mus. Comp. Zool.,
vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrical relationships) .— HAMANN, Bronn's
Klassen und Ordmmgen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK,
Proc. U. S. Nat. Mus., vol. 34, 1908, p. 474 (not Solanocrinus gracilis Goldfuss; renamed A. pergra-
cilis) ; Crinoids of the Indian Ocean, 1912, p. 33 (of P. H. Carpenter, 1888= Thalassometra pergra-
cilis}.— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7.

Anledon pubescens A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 139 (description; Albatross
station 4919).

Anledon pergracilis A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360, footnote (new
name for A. gracilis P. H. Carpenter, not Solanocrinus gracilis Goldfuss) ; Proc. U. S. Nat. Mus.,
vol. 34, 1908, p. 474 (same).

Thalassometra pergracilis A. H. CLARK, Smithsonian Misc. Coll., vol. 50, p. 3, 1907, p. 360 (listed;
new name for Anledon gracilis, preoccupied); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14
(listed); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 147 (compared with Th. attenuate,} ;
Zool. Anz., vol. 39, 1912, p. 426 (compared with Th. perplexa) ; Crinoids of the Indian Ocean, 1912,
p. 33 ( — Antedon gracilis P. H. Carpenter, 1888), p. 207 (synonymy; about 30 miles west of Middle
Andaman; about 485 fathoms; characters; summary of previous records); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 46 (published reference to specimens in B. M.; Challenger station
214; compared with Th. attenuala); Unstalked crinoids of the Siboga-Exped., 1918, p. 167 (in
key; range), p. 170 (references; record from the Andaman Islands not this species). — GISLEN,
Ark. Zool., vol. 19, No. 32, Feb. 20, 1028, p. 7 (comments).

Thalassometra pubescens A. H. CLARK, Smithsonian Misc. Coll., vol. 50, p. 3, 1907, p. 360 (listed);
Proc. U. S. Nat. Mus., vol. 34, 1908, p. 318 (southern Japan); Amer. Nat., vol. 42, No. 500,
1908, p. 542 (belongs to a group characteristic of the oceanic area); Geogr. Journ., vol. 32, No.
6, 1908, p. 603 (same); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed); Crinoids of the
Indian Ocean, 1912, p. 207 (synonymy; locality); Journ. Washington Acad. Sci., vol. 5, No. 6,
1915, p. 215 (southern Japanese species; range and its significance); Unstalked crinoids of the
Siboga-Exped., 1918, p. 168 (in key; range), p. 170 (references). — GISL£N, Ark. Zool., vol. 19A,
No. 32, Feb. 20, 1928, p. 7 (probably synonymous with gracilis and hirsuta).

Thalassometra gracilis GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 7, No. 25 (notes and
comments).

Diagnostic features. — The elements of the division series and the lower braehials
have the dorsal surface thickly beset with very fine spines; and the cirri are arranged
in 10 definite columns on the centrodorsal. The 10 arms are 60-80 mm. long, and the
cirri are 30 mm. long with 50-55 segments.

Description. — The centrodorsal is a low hemisphere with a roughened dorsal pole.
The cirrus sockets are arranged in 10 columns, 2 in each radial area (Gislen).

The cirri are about XX, 50-55, reaching 30 mm. in length; a few of the segments
are longer than broad, and the remainder are shorter and begin to overlap dorsally so as
gradually to develop a sharp spinous keel.

The radials are scarcely visible. The IBi'i are short and sharply convex in the
middorsal line. The IBr2 (axillaries) are broadly hexagonal. The elements of the
IBr series and first two braehials are slightly carinate and are more-or-less fringed with
small spines. They are also somewhat "wall-sided" with straight lateral edges that
extend to the hypozygal of the first syzygial pair. According to Gisl6n they cannot
be described as "very sharply flattened against each other."

The 10 arms are about 60 mm. long. They consist of elongately quadrate brachials
of which the outer overlap a little. The dorsal surface of the arms is spiny (Gisl6n).

174 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Syzygies occur between brachials 3+4, again between about brachials 14+15,
and thence at very irregular intervals.

P! is relatively large with about 20 segments of which the lowest are broad with
strong dorsal keels and flattened outer sides. Pa is similar but rather smaller. Pz
and Pt, are much smaller and are but slightly cariuate. The pinnules following in-
crease slowly hi length and at about the twentieth brachial they become boat-shaped
at the base owing to the expansion of the third and next few segments.

The disk is 6 mm. in diameter, rather incised and much plated, as are also the lower
parts of the arms. The pinnule ambulacra have fairly well developed side plates, but
the sacculi are small and rare.

The color in alcohol is brownish white.

Notes. — The preceding description is adapted from that of Carpenter, with a few
additions by Gislen. This is a slender species, about the build of Th. attenuate, though
more robust basally.

Carpenter called attention to the fact that in this species Pa is of the same type as
PI, smaller in size but with similarly carinate lower segments which are flattened on
the outer side. He said that the fringe of small spines on the elements of the IBr series
and lower brachials rather obscures their straight-edge and wall-sided character, though
this is very distinct in the smoother individuals, and the lateral flattening of the basal
segments in PI indicates the position of the type very clearly.

He said that the pinnules beyond the twentieth brachial until near the end of the
arms are remarkable for the character of the third and following segments which are
widely V-shaped in cross section so that the lower part of the pinnule has a boat-shaped
appearance when seen from the dorsal side. This expanded portion of the pinnule
encloses the gonad, and according to Carpenter recalls on a smaller scale a similar
arrangement in the pinnules of Hyocrinus. The enlargement of the lower segments of
the pinnules gradually disappears toward the ends of the arms and there is no indication
of it hi the pinnules of the youngest individual obtained.

This young individual shows much more of the radials externally than is visible in
the adults, while Pa shows hardly any trace of the enlarged and carinate basal segments
which appear in the adults.

A specimen from Albatross station 4919, which does not appear to differ in any
tangible features from Carpenter's Antedon gracilis, was described as a new species
under the name of Antedon pubescens. Its characters are as follows:

The centrodorsal is rather small, bluntly conical. The cirrus sockets are arranged
in 10 columns of usually three each.

The cirri are XXV-XXX, 50-55, slender, 30 mm. long. The proximal 10 or 12
segments beyond the basal are longer than broad, and the distal are broader than long
and develop rather low dorsal spines.

The ends of the basal rays are just visible in the interradial angles of the calyx
as small tubercles.

The radials are visible in the interradial angles over the ends of the basal rays.
The IBri are short and bandlike, sharply carinate, with raised and serrate edges. The
IBr2 (axillaries) are low and broad with a sharp keel in the proximal half.

The 10 arms are 80 mm. long. The first 6 or 7 brachials are oblong, those folio whig
wedge-shaped, becoming elongate distally. The elements of the IBr series and lower

A MONOGRAPH OF THE EXISTING CRIXOIDS 175

brachials are covered with numerous and thick-set very fine spines which become less
apparent after about the tenth brachial, at which point the brachials develop an over-
lapping border of very fine teeth and longitudinal striations, the latter on the distal
brachials becoming more pronounced and on the outer portion of the brachials breaking
up into numerous fine spines.

Syzygies occur between brachials 3+4, again between about brachials 15+16, and
distally at intervals of from 3 to 5 muscular articulations.

P, 7 mm. long with 21 or more short segments of which the basal 4 or 5 are produced
dorsally into a broad thin keel; all the segments have their edges armed with tufts of
very fine spines. P2 is 5 mm. long with 16 segments of which the basal 3 or 4 have a
thin dorsal keel which, however, is not nearly so wide as that on the preceding pinnule.
PI and P2 are somewhat flattened laterally. The three following pinnules are in general
similar to P2 but more slender. The pinnules of the next 3 or 4 pairs have the third-sixth
segments laterally expanded as a cover to the gonads, after which the pinnules become
slender and more elongated, reaching a length of 8 mm. with 15 segments.

After examining the type specimen of Antedon gracilis in the British Museum Prof.
Torsen Gislen said that gracilis is close to hirsula and pubescens, and probably all three
will turn out to belong to one species.

Localities. — Challenger station 214; off the Meangis Islands, southeast of Mindano,
Philippines (lat. 4°33' N., long. 127°06' E.); 914 meters; bottom temperature 5.4° C.;
blud mud; February 10, 1875 [P. H. Carpenter, 1888; Hartlaub, 1895; A. H. Clark,
1907, 1908, 1909, 1912, 1913, 1918; Gislen, 1928] (4, B. M.).

Albatross station 4919; Eastern Sea, about 90 miles west-southwest of Kagoshima
Gulf, Japan; Kusakaki Jima bearing N. 18° E., 17.6 miles distant (lat. 30°34'00" N.,
long. 129°19'30" E.); 804 meters; bottom temperature 5.4° C.; globigerina ooze;
August 13, 1906 [A. H. Clark, 1907, 1908, 1909, 1912, 1915, 1918; Gislen, 1928] (2,
U.S.N.M., 22631, 35590).

History.- — Antedon gracilis was described and figured by Dr. P. H. Carpenter in
his report upon the comatulids of the Challenger expedition published in 1888; his ma-
terial consisted of five specimens from station 214, off the Meangis Islands in 500 fath-
oms. In 1895 Dr. Clemens Hartlaub discussed the systematic and bathymetrical
relationships of Antedon gracilis.

In 1907 I described Antedon pubescens from two specimens from Albatross station
4919. In my first revision of the old genus Antedon published later in 1907 I listed
Thalassometra pubescens and also Thalassometra pergracilis, explaining that the latter
was a "new name for Antedon gracilis P. H. Carpenter, 1888, preoccupied (cf. Antedon
gracilis de Loriol, 1886)"; this was repeated in 1908. In 1908 Thalassometra pubescens
was listed as one of the crinoids occurring off southern Japan, and in two other papers
it was said to belong to a group characteristic of the oceanic fauna. In 1909 in my
revision of the family Thalassometridae pergracilis and pubescens were listed as species
of the genus Thalassometra, and in another paper published in the same year Thalasso-
metra pergracilis was compared with a new species, Th. attenuata. In a paper published
in 1912 it was compared with another new species, Th. perplexa. In my memoir on the
crinoids of the Indian Ocean published in 1912 Thalassometra pergracilis was recorded
from about 30 miles west of Middle Andaman in about 485 fathoms, and notes were
given on the specimen; Th. pubescens was listed, and the synonymy and range were

176 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

given. In a paper on the crinoids of the British Museum published in 1913 I gave
notes on four of Carpenter's specimens of Antedon gracilis that I had examined. In
1915 I again listed Thalassometra pubescens as a southern Japanese species, and dis-
cussed the significance of its range. In my memoir on the unstalked crinoids of the
Siboga expdeition published in 1918 pubescens and pergracilis were included in the key
to the species of the genus Thalassometra; pergracilis was given among the species with
the cirri arranged, more or less regularly, in 15 crowded columns, while pubescens was
given among those in which the cirri are arranged in 10 definite columns. Thalassometra
pubescens and Th. pergracilis were listed, and the synonymy and range of each were
given. I said that "I am now convinced that the specimen from the Andaman Islands
in about 485 fathoms of water which I recorded as Thalassometra pergracilis does not in
reality represent that species. It is in too poor condition for definite determination."

After examining Carpenter's specimens in the British Museum in August 1925,
Prof. Torsten Gislen in 1928 noted that the cirri are arranged in 10 columns on the
centrodorsal, not in 15 as stated by me in the Siboga report. My statement that the
cirri are arranged in 15 columns was based upon Carpenter's figure 4 on plate 12, which
clearly shows 3 columns in one radial area, and the same impression is given by figure 1
on plate 15. In drawing these animals errors of this sort are easily made unless part of
the centrodorsal is denuded of cirri. Gislen pointed out that the name pergracilis
suggested by me for this species in 1907 is quite superfluous. He noted that the Antedon
(Solanocrinus) gracilis mentioned by de Loriol in 1888 had originally been described as
Solanocrinus gracilis by Walther in 1886, so that Antedon gracilis of Carpenter is not
preoccupied. Gislen places Walther's Solanocrinus gracilis in the genus Pachyantedon,

THALASSOMETRA ECHINATA (P. H. Carpenter)

Antedon echinata P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 119 (de-
scription; Challenger station 170A), pi. 21, figs. 4, 5. — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27,
No. 4, 1895, p. 131 (systematic and bathymetrical relationships). — BATHER, Geol. Mag., dec. 4,
vol. 3, 1897, p. 120 (pinnules compared with those of Millericrinus recubariensis) . — BUTTON,
Index faunae Novae Zealandiae, 1904, p. 290 (listed). — HAMANN, Bronn's Klassen und Ordnungen
des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Crinoids of the Indian Ocean,
1912, p. 33 (of P. H. Carpenter, 1888= Thalassometra echinata).

Thalassometra echinata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed);
Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (belongs to a group characteristic of the oceanic area) ;
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 14 (listed); Crinoids of the Indian Ocean, 1912,
p. 208 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 46 (published
reference to specimens in B. M.; Challenger station 170) ; Unstalked crinoids of the Siboga-Exped.,
1918, p. 166 (in key; range), p. 171 (references).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20,
1928, p. 7, No. 26 (notes).

Diagnostic features. — The cirri have only 25 segments; the elements of the division
series and first two brachials have sharp straight edges fringed with spines, and very
narrowly flattened sides; and the cirri are arranged in 10 definite columns on the
centrodorsal. The 10 arms are 30 or 35 mm. long.

Description. — The centrodorsal is low hemispherical. From the figure the cirrus
sockets appear to be arranged in 10 columns of usually two each, but the surface of the
centrodorsal is not differentiated.

The cirri are about XX, 25. The fifth segment is the longest, twice as long as
broad; the segments in the outer half of the cirri are about as long as broad. The fifth

A MONOGRAPH OF THE EXISTING CRINOIDS 177

segment has a slight projection on its distal dorsal edge that becomes a spiny keel on the
short outer segments.

The radials are just visible. The IBrt are nearly oblong, not very convex, and are
barely united laterally. The IBr2 (axillaries) are about twice as long as the IBri,
broadly pentagonal, with slight backward projections. The elements of the IBr series
and first two brachials have sharp straight edges fringed with spines and very slightly
flattened sides. Professor Gisl6n noted that the spines on the ossicles are confined
almost exclusively to their borders ; there are two spines on the central dorsal surface.

The 10 arms are probably 30 or 35 mm. long. The first two brachials are nearly
oblong. Those following are obliquely quadrate and are as long as, or longer than, broad.

Syzygies occur between brachials 3+4, between about brachials 14+15, and
dis tally at intervals of from 3 to 5 muscular articulations.

PI is not much longer than Pa and consists of about 12 segments of which the first
5 are rather expanded, with the inner edges a little cut away; all have tufts of small
spines along the dorsal border. The next two pairs of pinnules (P2 and Pb and PS and
PC) decrease slowly in length and become less spinous. The later ones are long, slender,
and tolerably smooth.

The disk is 3 mm. in diameter, much incised and well plated. The pinnule
ambulacra have fairly definite side plates, and large sacculi are occasionally present.

The color in alcohol is light brownish white.

Locality. — Challenger station 170A, near the Kermadec Islands, north of New
Zealand (lat. 29°45' S., long. 178°11' W.); 1,152 meters; bottom temperature 4.17° C.;
volcanic mud; July 14, 1874 [P. H. Carpenter, 1888; Hartlaub, 1895; Bather, 1897;
Hutton, 1904; A. H.Clark, 1907, 1908, 1909, 1912, 1913, 1918; Gisle"n, 1928] (1,B. M.).

History. — Antedon echinata was described and figured by Dr. P. H. Carpenter in
1888 in his report on the comatulids of the Challenger expedition, his material consisting
of a single specimen from station 170A. Dr. Clemens Hartlaub in 1895 discussed the
systematic and bathymetrical relationships of Antedon echinata; Dr. F. A. Bather hi
1897 compared it with the fossil Millericrinus recubariensis; and Capt. F. W. Hutton
in 1904 included it in his list of New Zealand echinoderms.

In my revision of the genus Antedon published in 1907 echinata was transferred to
the new genus Thalassometra; in 1908 I twice mentioned Thalassometra echinata as
a member of a group characteristic of the oceanic area; and in 1909 in my revision of
the family Thalassometridae I listed it hi the genus Thalassometra. In my memoir
on the crinoids of the Indian Ocean published in 1912 I listed Thalassometra echinata
and gave the range, and in 1913 I noted that I had_ examined the type specimen hi the
British Museum. In my memoir on the unstalked crinoids of the Siboga expedition
published in 1918 echinata was included in the key to the species of Thalassometra, and
the synonymy and range were given. After exa'mining the type specimen at the
British Museum in 1925, Prof. Torsten Gisle"n in 1928 published a short note amplifying
the original description.

178 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

THALASSOMETRA PERIPOLOS A. H. Clark

PLATE 18, FIGURES 56, 57

Thalassometra peripolos A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, 1929, p. 635 (listed),
p. 651 (south of the Nicobar Islands, 560 fathoms; description; remarks), p. 653 (southeast of
Car Nicobar), pi. 40, figs. 3, 4.

Diagnostic features. — There are no long curved spines near the distal edge of the
brachials; the cirri are XVII, 31-38, from one-quarter to nearly one- third the arm
length; the arms (in the two known specimens) are 11 in number, the IIBr series being
4(3+4); the dorsal surface of the division series is thickly beset with excessively fine
spines which are often grouped in irregular bundles ; on the lower brachials these become
more scattered in the central portion of the dorsal surface; on the triangular and suc-
ceeding brachials the entire dorsal surface is beset with very fine spines, which become
longer on the slightly produced distal border.

Description. — -The centrodorsal is low, flattened hemispherical, with the almost
flat dorsal pole finely pitted and finely spinous. The cirrus sockets are arranged in one
and a partial second crowded marginal rows, there being usually three at the margin
beneath each radial.

The cirri are XVII, 31-38 (usually about 35), from 20 to 25 mm. long. The first
segment is very short, the second is slightly longer, the third is about two and one-half
times as broad as long, the fourth is half again as broad as long, and the fifth is some-
what longer than broad. The sixth, or more rarely the seventh, is a transition segment,
somewhat less than twice as long as broad, with the distal third white, in sharp contrast
to the dark brownish yellow proximal two-thirds. The following segments are similar,
but less constricted centrally. The segments succeeding slowly decrease in length
so that those in the terminal fourth of the cirri are half again as broad as long. On the
transition segment the distal edge dorsally is everted and slightly produced, and finely
dentate. As the segments become shorter this eversion of the distal edge dorsally
increases, becoming narrower and extending proximally so as to involve a triangular
area on the dorsal surface. In lateral view these processes appear as prominent blunt
dorsal spines arising from almost the whole of the dorsal surface of the segments with
the apex subterminal. On a few of the segments immediately preceding the penultimate
the process narrows into a small dorsal tubercle. The opposing spine is triangular,
arising from the entire dorsal surface of the penultimate segment, with the apex sub-
median to subterminal: its height is equal to about one-third the lateral width of the
segment. The terminal claw is about as long as the two preceding segments together,
and is evenly tapering and slightly and evenly curved.

The radials are entirely concealed by the centrodorsal in the median line, but their
anterolateral angles are visible interradially as small rounded tubercles which usually
are armed with exceedingly short fine spines. The IBri are very short, crescentic or
bandlike, becoming narrow laterally, and are in close lateral contact. Their surface
is thickly covered with excessively fine spines which are often grouped on irregular
pedicels suggesting paxillae. The IBr2 (axillaries) are about three times as broad as
long, triangular or subrhombic, with the lateral angles truncated and in close lateral
contact with those of their neighbors. The anterior edges are slightly thickened.
The entire surface is thickly beset with excessively fine spines which are more or less
grouped on low irregular bases. The division series are broad, in close lateral contact,

A MONOGRAPH OF THE EXISTING CRINOIDS 179

and sharply flattened laterally. They are only very moderately convex dorsally. The
IBr series are 4(3 + 4).

The 11 arms are 80 mm. long. The first brachials are very short, four or five times
as broad as the median length, half again as long exteriorly as interiorly, in close
apposition and flattened against their fellows. The proximal and distal edges are
slightly thickened and densely beset with excessively fine spines, which are also found
more or less on the remainder of the dorsal surface. The second brachials are twice
as large as the first, wedge-shaped, twice as long exteriorly as interiorly; the edges
are slightly thickened and densely spinous, and the dorsal surface is more or less
spinous. On the outer lateral edges of both the first and second brachials the spines
become longer and are grouped on more or less prominent irregular bases. The first
syzygial pair (composed of brachials 3 + 4) is more than twice as broad as long, oblong
or slightly longer interiorly than exteriorly. The proximal and distal borders are
everted and densely spinous and there is a double row of spines along the syzygial
line, but otherwise the dorsal surface is devoid of spines. The next four brachials are
slightly wedge-shaped, about three times as broad as long, with the edges, both proxi-
mal and distal, rather thickly everted and densely spinous, and numerous spines on
the dorsal surface. The following brachials are triangular, about as long as broad,
with the entire dorsal surface beset with very fine spines which become longer on the
slightly produced, but not overlapping, distal edge. Distally the brachials become
wedge-shaped, as long as broad, and terminally longer than broad and ultimately
elongate, while at the same time the spines on the dorsal surface become longer, more
prominent, and more uniform in size, and are inclined so that they are. directed diago-
nally outward from the arm.

PI is 8 mm. long with 20-21 segments and tapers evenly from the base to the
slender tip. The segments are at first broader than long, becoming about as long as
broad on the eighth and terminally longer than broad. The earlier segments have a
broad band of fine spines on the distal edge, and after about the eighth the whole
outer side becomes spinous in addition.

P2 is somewhat shorter and more slender than PI and is composed of about 16
segments. P3 is very slightly shorter than P2, with 16 segments. The genital pinnules
have the fourth-seventh segments slightly broadened.

Notes. — The specimen described is from south of the Nicobar Islands in 1,024
meters. A smaller specimen from southeast of Car Nicobar is quite similar to the one
described, though slightly smaller. It also has 11 arms, one IIBr 4(3 + 4) series being
present. All of the arms arc broken off at the first brachial syzygy. The cirri are
XXII, 32-34, from 20 to 23 mm. in length. The apical cirri arc smaller and shorter
than the peripheral, 15 mm. long with 26 segments. The basal cirrus segments have
finely spinous ends and a few short spines on the dorsal surface.

Localities. — South of the Nicobar Islands; 1,024 meters; cable repair ship Patrol,
Eastern and Associated Telegraph Company [A. H. Clark, 1929] (1, B. M.).

Southeast of Car Nicobar (lat. 7°15'24" N., long. 92°59'00" E.); cable repair
ship Patrol, Eastern and Associated Telegraph Company [A. H. Clark, 1929] (1, B. M.).

Remarks. — This species is evidently most closely related to Th. multispina of the
south Atlantic from which it differs in the larger size, greater number of cirrus segments,

180 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and less uniform distribution of spines on the dorsal surface of the elements of the
division series.

THALASSOMETRA MULTISPINA (P. H. Carpenter)

Antedon multispina P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, part 60, 1888, p. 117 (de-
scription; station 344), p. 248 (description; station 344 [but not station 135G=7%. setosa]),
pi. 13, figs. 1-3, pi. 69, figs. 1-4 [not pi. 14, figs. 5-7=Koehlermetra porrecta, or pi. 50, figs. 3-6=
Th. setosa]; Journ. Linn. Soc. (Zool.), vol. 24, 1891, p. 66 (comparison with [Stiremetra] lusi-
tanica). — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (in Basicurva group;
bathymetric relationships), pp. 134, 136 (comparison with Th. agassizii). — LANG, Text book of
comparative anatomy, 1896, vol. 2, p. 375, fig. 326D. — MINCKERT, Arch. Naturg., Jahrg. 71,
1905, vol. 1, Heft 1, pp. 170 and following (syzygies; regeneration). — HAMANN, Bronn's Klassen
und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, pp. 1578, 1582 (listed).— HARTLAUB, Mem.
Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 285 (in the Granulifera group; doubtless different from
granulifera), p. 286 (referred by Clark to the Thalassometrinae) .

Thalassometra multispina A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed) ;
Amer. Nat., vol. 42, No. 500, 1908, p. 542 (belongs to a group characteristic of the oceanic area);
Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (same) ; Proc. Biol. Soc. Washington, vol. 22, 1909,
p. 14 (listed); Proc. U. S. Nat. Mus., vol. 40, 1911, p. 8 (west coast of Africa), p. 38 (synonymy;
near Ascension, 420 fathoms, volcanic sand) ; Smithsonian Misc. Coll., vol. 61, No. 15, 1913,
p. 47 (published references to specimens in the B. M. ; Challenger Sta. 344 [but not 135= Th.
setosa]; notes); Unstalked crinoids of the Siboga-Exped., 1918, p. 166 (in key; range), p. 171
(references); The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range). — GISLEN^
Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 6, No. 24 (notes on specimens in the British Museum)
— A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 654 (compared with
Th. peripolos, sp.nov.). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934^
p. 22.

Diagnostic features . — The cirri are arranged in 15 crowded columns on the centro-
dorsal; the elements of the division series and lower brachials have numerous fine spines
on the dorsal surface. The 10-12 arms are 50 mm. long, and the cirri have 25-30
segments.

Description. — The centrodorsal is low-hemispherical. From the figures the cirrus
sockets appear to be arranged in 15 columns, but the surface of the centrodorsal is not
differentiated into radial areas.

The cirri are about XX, 25-30; a few of the segments are longer than broad, and
the remainder are shorter and overlap slightly so as to develop a dorsal spine.

The radials are not visible in the adult. The IBrt in the adult are very short, and
the IBr2 (axillaries) are widely pentagonal. The axillaries and first brachials have
flattened outer sides and straight lateral edges, and the inner side of the second brachial
and of the hypozygals of the first syzygial pair are also flattened. There are numbers
of small spines on the elements of the IBr series and arm bases. The IIBr series, when
present, are 4(3+4) and resemble the IBr series.

The 10-12 arms are probably about 50 mm. long. Of the four specimens described
by Carpenter three had 10 arms and one had 12, with two IIBr 4(3+4) series present.
The brachials are elongately quadrate with tufts of numerous small spines at one or
both ends.

Syzygies occur between brachials 3+4, again from between brachials 10 + 11 to
between brachials 15+16, and distally at intervals of 4 or 5 muscular articulations.
In arms arising from a IIBr 4(3+4) series the first syzygy is between brachials 1 + 2.

A MONOGRAPH OF THE EXISTING CRINOIDS 181

P, is composed of about 25 segments the lowest of which are broad with their inner
edges a little cut away and the outer sides slightly flattened. The pinnules of the next
pair are much smaller, and those following gradually increase in length; in these the
lower segments are at first broadly V-shaped, later more elongated. From about the
twelfth brachial onward the pinnules have the third and next following segments
expanded for the protection of the gonads, having a broadly V-shaped cross section,
though this is less marked than in Th. gracilis. In the specimen with two IIBr 4(3+4)
series PI consists of rather massive segments with their inner edges cut away a little
and the outer sides flattened. It is much larger than its successors.

The disk is 4 mm. in diameter and is well plated. Side plates are fairly well
developed on the pinnule ambulacra, and sacculi are moderately abundant.

The color in alcohol is light brownish white.

Notes. — In the youngest of the three immature individuals not only the basals,
but also portions of the radials are concealed, and the pinnules of the first two pairs
have appeared, though from the sixth to the thirteenth brachials the arms are devoid
of pinnules. In an older individual the radials are only just visible externally, though
the IBrj are relatively much longer than in the mature form. All the brachials are
provided with pinnules, although the lowest ones are quite small, Pj being much more
like its successors than in the adult, while there is but little trace of any expansion in
the lower segments of the genital pinnules.

The spines on the cirri are present from the first, but those on the division series,
arms, and pinnules do not appear until after the pentacrinoid stage, while the lateral
flattening of the radials and lower brachials is one of the last characters to make its
appearance.

Locality. — Challenger station 344; south Atlantic near Ascension (lat. 7°54'20"
S., long. 14°28'20" W.) ; 768 meters; volcanic sand; April 3, 1876 [P. H. Carpenter, 1888,
1891;Hartlaub, 1895, 1912; Lang, 1896; Minckert, 1905; A. H. Clark, 1907, 1908, 1909,
1911, 1913, 1918, 1923, 1929; Gislen, 1928, 1934] (2, B. M.).

History. — This species was described and figured under the name of Antedon
multispina by Dr. P. H. Carpenter in his report upon the comatulids of the Challenger
expedition published in 1888. The description was based upon four broken individuals
from station 344. The three pentacrinoid larvae also secured at this station and con-
sidered by Carpenter as belonging to this species possibly represent Crotalometra por-
recta (see Part 2, p. 521, pi. 34, figs. 1207-1209). Antedon multispina was first described
in the Basicurva group, and the only locality given was station 344. A supplementary
description, with additional figures, was given under the Granuli/era group, which was
based upon a single mutilated specimen from station 135G. This specimen is herein
regarded as representing a different species, Th. setosa (see page 182).

In a discussion of Antedon (Stiremetra) lusifanica published in 1891 Carpenter
compared the occurrence of a syzygy between brachials 1+2 on arms arising from a
IIBr 4(3+4) series with the condition in Antedon (Thalassomctra) multispina and in
Antedon (Crotalometra') porrecta. He said that multispina "like Antedon lusitanica, may
sometimes have no more than ten arms, as in the six 'Challenger' specimens from Ascen-
sion; while the single individual from Tristan D'Acunha [=Th. setosa] possesses one
bidistichate [IIBr 2] and two tridistichate [IIBr 4(3+4)] series, two of the arms borne
on the latter having a syzygial union between the first two brachials, while the other

182 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

two are of the ordinary type, with a syzygy in the third brachial [i. e., between brachials
3+4]." He said that "should the tridistichate condition eventually prove to be common
in these two species, it may become necessary to unite them under one name. At
present the main points of difference between them, apart from the characters of the
arm-divisions, appear to lie hi the longer cirri and less spinous arms of A. lusitanica,
in which also the joints of the genital pinnules, as the Madeira specimens show, are some-
what produced upward on the outer side, as is so markedly the case in Antedon [Chari-
tometra] basicurva, but there is nothing of this kind in A. multispina."

In 1895 Dr. Clemens Hartlaub discussed the systematic and bathymetrical rela-
tionships of Antedon multispina and compared it with his new species A. (Thalassometra)
agassizii. In 1905 Wilhelm Minckert discussed the distribution of the syzygies in
A. multispina.

In my revision of the genus Antedon published in 1907 multispina was assigned to
the new genus Thalassometra, and in two papers published in 1908 Thalassometra multi-
spina was said to belong to a group characteristic of the oceanic area. In my revision
of the family Thalassometridae published in 1909 Thalassometra multispina was listed.
In a paper on the crinoids of the coasts of Africa published in 1911 I included Th.
multispina, giving the synonymy and the record from near Ascension.

Dr. Clemens Hartlaub, in discussing Carpenter's Granulifera group in 1912, said
that, without expressing a definitive judgment, in his opinion Antedon angusticalyx,
A. inaequalis, and A. distincta were synonyms of A. granulifera, but that A. porrecta
and A. multispina, were doubtless distinct.

In a paper on the crinoids of the British Museum published in 1913 I noted that
I had examined two specimens and one pentacrinoid young from Challenger station 344,
and that the spines covering the animal are exceptionally fine. In my report upon the
unstalked crinoids of the Siboga expedition published in 1918 multispina was included
in the key to the species of Thalassometra and the range was given as near Ascension
Island in 756 meters. The references given under Thalassometra multispina included
both multispina and setosa. In my report on the crinoids of the Ingolf expedition
published hi 1923 I listed Thalassometra multispina, saying "Only known from near
Ascension; 768 metres." The specimen from off Tristan da Cunha in 1,005 meters I
listed as Thalassometra setosa. Both multispina and setosa were included in my key to
the species of Thalassometra.

Prof. Torsten Gislen in 1928 gave notes on a young specimen of Thalassometra
multispina and said that older specimens had fewer cirri. He gave the locality as
Challenger station 135G, which is the locality for Th. setosa; but all but one of the speci-
mens must have come from station 344, the locality for Th. multispina.

In 1929 I compared a new species, Thalassometra peripolos from the Nicobar Is-
lands, with Th. multispina. Professor Gislen hi 1935 discussed the arm structure of
Thalassometra multispina.

THALASSOMETRA SETOSA (A. H. Clark)

Antedon, sp. WYVILLE THOMSON, The Atlantic, vol. 2, 1877, p. 193 (near Tristan; 550 fathoms).
Antedon setosa P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 34 (off Tristan

da Cunha; nomen nudum).
Anledon multispina (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 248

(station 135G; notes), pi. 50, figs. 3-6, and following authors.

A MONOGRAPH OF THE EXISTING CRINOIDS 183

Thalassometra multispina (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 47
(Challenger station 135 [but not station 344= Th. multispina}). — GISL£N, Ark. Zool., vol. 19A,
No. 32, 1928, p. 24 (young specimen mentioned, but not pentacrinoids Xos. 1-3).

Thalassometra setosa A. II. CLARK, The Danish Ingolf-Exped., vol. 4, Xo. 5, Crinoidea, 1923, p. 40
(range), p. 57 (in key).

Diagnostic features. — The cirri are arranged in 15 crowded columns on the centro-
dorsal; the elements of the division series and lower brachials have a few scattered fine
spines on the dorsal surface. There are 13 arms probably about 50 mm. long, and the
cirri have 35 segments.

Characters. — The centrodorsal is flattened-hemispherical with the cirri apparently
irregularly arranged, possibly in 15 columns, or 3 columns in each radial area.

The cirri are about XXXII, in general similar to those of Th. multispina, but they
may have as many as 35 segments.

The radials are visible. The IBr series, brachials, and pinnule segments are less
distinctly spinous than those of Th. multispina.

There are 13 arms, two IIBr 4(3+4) series and one IIBr 2 series being present.
On the arms arising from the IIBr 2 series the first syzygy is between brachials 3+4;
but in the arms following the two IIBr 4(3+4) series one has the first syzygy between
brachials 1+2, while in the other it is between bracbials 3+4.

PI has somewhat the same flattened appearance on the outer side as is traceable in
Th. multispina, but it is so slight as to be hardly recognizable except by a trained eye,
and the same may be said of the lateral flattening of the lower brachials.

The plating of the disk is very incomplete, and the ambulacral skeleton of the pin-
nules is by no means well differentiated.

The characters given above are taken from Carpenter's notes on the only known
specimen, supplemented by his figure and Gislen's statement of the number of the cirri.

Locality. — Challenger station 135G; south Atlantic, off Tristan da Cunha (lat.
37°10'50" S., long. 12°18'30" W.); 1,005 meters; hard ground; October 18, 1873
[Wyville Thomson, 1877; P. H. Carpenter, 1888; A. H. Clark, 1913, 1923; Gislen,
1928] (1, B. M.).

History. — This species was first mentioned in 1877 by Prof. Sir Wyville Thomson
who noted that the Challenger dredged Antedon, sp., off Tristan da Cunha in 550 fathoms.

In the introductory chapter on geographical and bathymetrical distribution in the
Challenger report on the comatulids published in 1888 Dr. P. H. Carpenter mentioned
"Antedon setosa from off Tristan da Cunha" (p. 34), but in the descriptive portion of
the work he included the single mutilated specimen from station 135G under Antedon
multispina in his supplementary account of that species (p. 248) as a member of the
Granulifera group. He gave a number of features by which the specimen from Tristan
da Cunha is distinguished from the four dredged near Ascension (=Th. multispina),
and figured it.

In my earlier papers this form was included in Thalassometra multispina, and I did
not distinguish the two in my notes on the crinoids of the British Museum published
in 1913. In my report on the crinoids of the Ingolf expedition published in 1923 setosa
was included in the key to the species of Thalassometra occurring in the Atlantic, and
the locality and depth were given. In 1928 Prof. Torsten Gislen noted that the speci-
men of Thalassometra multispina from Challenger station 135G had the cirri about
XXXII.

184 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

THALASSOMETRA OMISSA (Koehler)

Antedon omissa KOEHLER, Re'sultats des campagnes scientifiques accomplies sur son yacht par Albert
1 «r Prince souverain de Monaco, fasc. 34, 1909, p. 268 (description; Princesse- Alice station 1713,
1904), pi. 32, fig. 10. — MORTENSEN, Handbook of the echinoderms of the British Isles, 1927,
p. 25.

Thalassometra omissa A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 7 (occurs on the north-
western coast of Africa) , p. 37 (synonymy; locality); Unstalked crinoids of the Siboga-Exped.,
1918, p. 166 (in key; range), p. 171 (synonymy); The Danish Ingolf-Exped., vol. 4, No. 5,
Crinoidea, 1923, p. 40 (range), p. 57 (in key). — -MORTENSEN, Handbook of the echinoderms of
the British Isles, 1927, p. 25.

Diagnostic features. — The cirri are arranged in 15 crowded columns; the elements
of the division series and lower brachials are smooth dorsally except for a few minute
spines along the proximal and distal edges- and the brachials have the distal border
thickened, forming a transverse crest that bears a few very fine spines. There are 10
arms, and the cirri are about 17 mm. long with 21 segments.

Description. — The centrodorsal is hemispherical, with the cirrus sockets apparently
arranged in 15 columns.

The cirri are XX +, 21, about 17 mm. long. The two first segments are very short,
the third is slightly longer, the fourth and fifth are much longer, and the sixth, which
is the longest, is about twice as long as broad. Beyond this point the length gradually
decreases to the twelfth which, with the segments following, is about as long as broad.
From the sixth segment onward a small spine appears toward the distal end which,
gradually moving toward the middle of the segments, continues to the end of the cirrus.
There are X principal cirri and a few other smaller ones that rise vertically between
the arms.

The radials are partially visible. The IBri are almost twice as broad as long with
the distal border slightly incised by the IBr2 (axillaries), of which the dorsal surface
is slightly convex, the distal angle is rather sharp, and the dorsal surface is depressed
toward the central portion in such a way that the articular border is somewhat pro-
jecting. The elements of the IBr series and the first brachials are slightly flattened
laterally. The diameter of the proximal portion of the animal is 4 mm.

The 10 arms are all broken, the longest arm stump being only 30 mm. long. The
first two brachials are short, broader than long, and those following gradually elon-
gate, at the same time becoming narrower. The dorsal surface of the first two brachials
is depressed in such a way as to render the proximal and distal edges, especially the
latter, slightly projecting. The brachials following show the same central depression,
the distal edge projecting as far as the twelfth or fifteenth. Under a lens it is seen that
this raised edge is provided with very short spines difficult to make out that appear
from the seventh or eighth bracliial onward.

Syzygies occur between brachials 3 + 4, again between brachials 11 + 12, or some-
times 12+13, and distally at intervals of from 4 to 6 muscular articulations.

PI and P» are large and well developed with about 12 segments of which the
first three or four are broader than long, those succeeding becoming elongated and
very slender. They are slightly carinate. Under the microscope these pinnules show
very fine spines, short and sparse, much less abundant than the spines in Th. echinata.
P2 is very short, with only 6 segments. The pinnules following increase slightly in
length. On about the eighth there are 8 segments, and a little farther on, 9. The

A MONOGRAPH OF THE EXISTING CRLNOID8 185

segments increase in length as their number increases. On a detached arm fragment
there are pinnules 5 mm. long with 10 segments. The arrangement of the pinnules
resembles that in Th. latipinna.

Notes. — Professor Koehler said that this species is most closely related to Th.
echinata from which it is distinguished by the less numerous cirri with less numerous
segments. The brachials are shorter with the distal border thickened forming a trans-
verse crest which bears only a few very fine spines. Although strongly developed,
PI bears only a few very fine and scattered spinules which are invisible to the naked eye.

Locality. — Princesse-Alice station 1713; off the southeastern coast of Tenerife,
Canary Islands (lat. 28°04' N., long. 16°49'30" W.); 1,330-1,340 meters; August 1,
1904 [Koehler, 1909; A. H. Clark, 1911, 1918, 1923;Mortensen, 1927] (1, Monaco Mus.).

History. — Prof. Rene Koehler described and figured Antedon omissa in 1909 from a
single specimen in rather poor condition that had been dredged by Prince Albert I of
Monaco's yacht Princesse-Alice in 1904 at station 1713.

In a paper on the crinoids of the African coasts published in 1911 I included Thalas-
sometra omissa and gave the range. In my memoir on the unstalked crinoids of the
Siboga expedition published in 1918 omissa was included in the key to the species of
Thalassometra and the synonymy and range were given. In my memoir on the crinoids
of the Ingolf expedition published in 1923 omissa was included in the key to the Atlantic
species of Thalassometra, and the range was given. Dr. Th. Mortensen in his handbook
of the echinoderms of the British Isles published in 1927 included a notice of Thalas-
sometra omissa.

THALASSOMETRA sp.

Thalassometra pergracilis (part) A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 207; Unstalked
crinoids of the Siboga Expedition, 1918, p. 170.

Locality. — Investigator; about 30 miles west of Middle Andaman; about 887 meters
(485 fathoms) [A. H. Clark, 1912, 1918] (1, I. M.).

Remarks. — Regarding this individual I wrote in 1912:

One mutilated specimen, agreeing well with Carpenter's description and figures. The centrodorsal
is rounded conical, 4 mm. broad at the base and 3 mm. high; the cirrus sockets are arranged in ten
columns, two to each radial area, those of each radial area being separated interiorly by a rather strong
ridge, exteriorly in close apposition with the columns of adjacent radial areas; the dorsal pole is rough,
covered with irregular tubercles; the disk is almost entirely covered with small rounded concretions;
the disk ambulacra are bordered with similar, but somewhat smaller and more thickly set, plates which
become radially elongated about the mouth; the perisome of the arms is covered with small round
concretions, and the interbrachial perisome with large flat plates.

In 1918 I wrote that I was convinced that this specimen does not in reality represent
Th. pergracilis (=gracilis), and that it is in too poor condition for definite determination.

Genus HORAEOMETRA A/H. Clark

Antedon (part) VON GRAFF, Bull. Mus. Comp. Zool., vol. 11, No. 7, 1883, p. 133, and following authors.

Thalassometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360.

Cosmiometra (part) A. H. CLARK, Unstalked crinoids of the Sttoffa-Exped., 1918, p. 154.

Horaeometra A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 160 (only included species
//. duplex [P. H. Carpenter]); Univ. Iowa Studies in Nat. Hist., vol. 9, No. 5, 1921, p. 12 (confined
to the West Indies), p. 19 (in key); The Danish 7n0oC/-Exped., vol. 4, No. 5, Crinoidea, 1923, p.
40 (range). — GISL£N, Kungl. Fysiogr. Sallsk. Handl., new ser., No. 11, 1934, p. 18.
843803 — 50 13

186 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Diagnosis. — A genus of Thalassometridae in which the third-fifth segments of the
genital pinnules are greatly expanded, forming a roof over the gonads; there are 10-22
arms with all the division series 2; and the cirri are arranged in 10 columns on the
centrodorsal. The single included species is small and delicate, with the arms up to 50
mm. in length.

Geographical range.— From northern Cuba eastward and southward along the An-
tillean chain to St. Vincent and ?Grenada.

Bathymetrical range. — From 159 to 479 meters.

Thermal range.— From 8.3° to 16.67° C.

History. — The only known species of this genus was first mentioned as Antedon
duplex by Prof. Ludwig von Graff in 1883, this name having been furnished him by
Dr. P. H. Carpenter, who later used it in his report upon the comatulids of the Challenger
expedition published in 1888. In my first revision of the old genus Antedon published in
1907 duplex was referred to the new genus Thalassometra. In my revision of the family
Thalassometridae published in 1909 I included Antedon duplex in a list of species which
I was unable to place satisfactorily. In my report upon the unstalked crinoids of the
Siboga expedition published in 1918 I included the new generic name Horaeometra in
a key to the genera of the subfamily Thalassometrinae, and under this name I listed
Horaeometra duplex, with its synonymy. At the same time I included the new specific
name koehleri in the key to the species of the genus Cosmiometra, giving as the range
St. Vincent, in 158 meters; C. koehleri subsequently proved to be based upon a specimen
of H. duplex. Since 1918 the status of the genus Horaeometra has remained unchanged.

HORAEOMETRA DUPLEX (P. H. Carpenter)

PLATE 6, FIGURE 24
[See also vol. 1, pt. 2, fig. 321, p. 227.]

Antedon duplex VON GRAFF, Bull. Mus. Comp. Zool., vol. 11, No. 7, 1883, p. 133 (nomen nudum; off
St. Vincent, 124 fins.; myzostomes) . — VON GRAFF, Challenger Reports, Zoology, vol. 10, pt.
27, 1884, pp. 17, 18, 75 (nomen nudum; Blake station 269; myzostomes). — P. H. CARPENTER,
Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 54 (specific formula), p. 207 (10-armed
Blake species), p. 208 (both 10-armed and multibrachiate) , p. 211 (myzostomes), p. 212 (in key
to the species of the Spinifera group), p. 217 (compared with [Sliremetra] lusitanica) , pp. 367, 368
(bathy metrical range), pp. 375, 378 (Caribbean islands and Straits of Florida, 88-262 fms.). —
HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 130 (systematic and bathymetrical
relationships), p. 135 (compared with A. [Thalassometra] agassizii). — MINCKERT, Archiv Naturg.,
Jahrg. 71, 1905, vol. 1, Heft 1, p. 211 (syzygies; arm division). — HAMANN, Bronn's Klassen
und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, pp. 1578, 1581 (listed). — A. H. CLARK,
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (not placed in a revision of the Thalassometri-
dae).— HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 280 (in the Blake collection),
p. 309 (in the Spinifera group; history), pp. 366-370 (Blake stations 232, ?249; detailed descrip-
tion and discussion), pi. 3, figs. 2, 4-11, pi. 14, figs. 5, 10, 13.

Thalassometra duplex A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed).

Cosmiometra koehleri A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 154 (in key;
range; based on Antedon duplex Hartlaub [part], Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912,
p. 366, pi. 3, figs. 2, 4; pi. 14, figs. 5, 10).

Horaeometra duplex A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 160 (references);
The Danish 7njoi!/-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range). — H. L. CLARK, Mem.
Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 9 (Atlantis stations 2999, 3303, 3437, 3465,
3466, 3467, 3478, 3479, 3480; off the north coast of Cuba, about 100 fathoms).

A MONOGRAPH OF THE EXISTING CRINOIDS

187

Diagnostic features. — The broad and conspicuous expansion of the third-fifth
segments of the genital pinnules at once distinguishes this species from all others in
the family Thalassometridae. It is a small and delicate form with the 10-22 (usually
15-20) arms reaching 45-50 mm. in length, and the cirri 15-20 mm. long with 32-50
(usually 32-35) segments.

The great variation in the number of the arms is very deceptive, and it is often
difficult to believe that the slender 10-armed individuals can belong to the same species
as the much stouter examples with 20 arms.

Description. — The centrodorsal is broad, truncated conical, with the cirrus sockets
arranged in ten columns of three or four each, the two columns of each radial area
being rather widely separated from each other but closely crowded against the columns
of the areas adjacent. In each midradial region there is a deep V-shaped space between
the columns of cirrus sockets which accommodates the posterior process from the IBr
axillary, the rounded posterior end of this lying sometimes as much as halfway between
the proximal rim and the dorsal pole. When the posterior process does not descend
so deeply the pairs of columns of cirrus sockets are separated by a very deep and broad
V-shaped furrow with a V-shaped cross-section. The dorsal pole is broad, flat, rough,
or papillose.

The cirri are XII, 32-35, from 15 mm. to 17 mm. long; the longest proximal
segments (the 5th-7th) are twice as long as broad; from the seventh or eighth onward
the segments bear very prominent long and slender dorsal spines; the fifth is a well-
marked transition segment.

The ends of the basal rays are visible as small rounded tubercles in the interradial
angles. The radials are concealed. The IBri form a very narrow border between
the posterior process of the IBr2 (axillary) and the centrodorsal. The IBr2 are broader
than long with all four sides deeply concave so that the lateral quarters are exceedingly
narrow with parallel sides which distally rise to a rather sharp angle — somewhat less
than a right angle — and proximally to a relatively deep and narrow rounded posterior
process which is longer than the anterior angle, reaching downward to between the
first or second cirrus sockets of the interradial columns. The IIBr series are of two
elements, and resemble the IBr series. IIIBr series of two ossicles are occasionally
present. The division series and arm bases are deep, in close lateral contact, and
sharply flattened against their neighbors.

The arms are from 10 to 20 (usually between 15 and 20) in number, about 50 mm.
long. There is a broad roughened finely spinular band on the arms which on the
triangular brachials becomes lines of serrations.

PI is from 3.5 mm. to 5.0 mm. long, rather stout basally but rapidly tapering and
becoming slender beyond the sixth segment, composed of 11-14 segments of which
the sixth and following are longer than broad. P2 is 2.5 mm. long, much more slender
than Pj and evenly tapering from the base to the tip, composed of 7 or 8 segments.
P3 is smaller and more slender than P2, becoming very slender beyond the second
segment, about 2. 0 mm. long with 8 segments. On P4 and the following pinnules the
third-fifth segments are very greatly expanded, the expansion being at a maximum
on the third or third and fourth and gradually tapering away on the sixth so that the
pinnule as a whole has a leaflikc outline. The distal pinnules are 3 mm. long with 11
segments.

188 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Notes. — After the death of Dr. P. H. Carpenter the Blake collection of comatulids
was sent to Dr. Clemens Hartlaub for report. In the collection Hartlaub found three
specimens of this species from Blake station 232. Two of these were in the same jar
with the label "A. duplex." The third which, in spite of many differences, he regarded
as representing the same species, he found with some specimens labeled "A. brevipinna."
Hartlaub noted that Carpenter apparently had had more specimens than he had
received, for in the Challenger report he had given the bathymetric range as 88-262
fathoms. The latter depth was that of a station off Grenada, and also of one in the
vicinity of St. Vincent, so that perhaps Carpenter had had specimens from station 249,
off Grenada, in 262 fathoms. It is possible, he said, that one of the specimens received
by him was from station 249 and that the label had been lost.

Hartlaub remarked that in the Challenger report Carpenter had placed this species
in both the Spinifera and Basicurva groups.

Hartlaub thus described the two specimens that had been labeled A. duplex by
Carpenter. The centrodorsal is subconical with strong interradial ridges the ventral
ends of which are strongly produced upward in the interradial angles. These inter-
radial ridges, each of which is bordered by a column of 4 or 5 cirrus sockets on either
side, are well marked. In the midradial line the columns of cirrus sockets are separated
by lower ridges so that as a whole the centrodorsal bears 10 ridges, five strong inter-
radial and five weaker radial. The moderately rounded dorsal pole is smooth and free
of cirri.

The cirri are about XL, about 50, up to 20 mm. long, and slender. The segments
in the proximal half, with the exception of the basal, are somewhat elongated; those in
the distal half are uniformly very short and bear small spines on the distal end. The
transition from the longer segments in the proximal half of the cirri to the very short
segments in the distal half is very abrupt as in Stylometra spinifera.

The radials are not visible in the larger specimen, though they appear in the
smaller. The IBr, are very flat, and in the larger specimen are partially concealed by
the centrodorsal. The IBr2 (axillaries) are short, almost rhombic, and on the proximal
border bear a strong process with a sharply set-off base that passes into the pronounced
elevation of the IBrj, forming a strong synarthrial tubercle. The IIBr series are 2.
The IIBr2 (axillaries) are hexagonal, like the IBr axillaries with a proximally directed
process which forms a pronounced articular tubercle with the IIBrj. Single IIIBr
series are present in the larger specimen.

The smaller specimen has 10 arms about 20 mm. long, and the larger has 20 arms
about 45 mm. long, though in life it probably had 22. The surface of the arms is smooth.
The first 9 or 10 brachials are more or less discoidal and are all short, the first being the
shortest. The form of the second brachials is somewhat variable, according to the
point of origin of the arm. On arms arising from a IBr axillary the second brachial has
more the form of an axillary. The first syzygial pair (composed of brachials 3+4) is
approximately square. From the tenth onward the brachials are approximately tri-
angular. Their proximal and distal ends are arched and have a small sharp lateral
point that alternates on succeeding brachials.

Syzygies occur between brachials 3+4, again between brachials 22 + 23, and distally
at intervals of 6 muscular articulations. On arms arising from a IBr axillary, on which

A MONOGRAPH OF THE EXISTING CRINOIDS 189

the second brachial has the form of an axillary to a marked degree, the first syzygy is
between brachials 5+6.

PI is markedly longer and stouter than P2. In the larger specimen it is 5 or 6 mm.
long, stout basally, and composed of 10 segments of which the second, and especially
the third, are markedly broadened and those following taper rapidly. P8 is about half
as long as PI with about 10 segments of which none are especially broadened, the width
of the segments tapering gradually from the base of the pinnule to the tip; the majority
of the segments are somewhat elongated. P3 is very similar to P2 in thickness and in
length, but the fourth and fifth segments sometimes show a thin leaflike expansion over
the gonads, which are here only slightly developed. P4 is somewhat longer and shows
hi pronounced measure the thin leaflike expansion of the third, fourth, and fifth seg-
ments, the fourth being the most broadened. The following pinnules as far as P8 are
similar, and all these show gonads on the ventral side. Whether the pinnules with
strongly developed expansion of the earlier segments extended farther out along the
arms could not be definitely ascertained. The pinnules of about the middle third
of the arm are all very small.

The disk is not visible. The ambulacral plating of the pinnules consists of high
slide plates and covering plates. Sacculi are not recognizable.

The color in alcohol is brownish white.

Hartlaub remarked that this description differs in some points from the notes
published by Carpenter. Carpenter said that the cirri are "without definite arrange-
ment" whereas they are arranged in 10 definite columns; he also said "Radial axillaries
long," whereas apart from the proximally directed process in the middle of the proximal
border they are very short.

The third rather small specimen that was found with others identified as A.
brevipinna agrees with the other two. The centrodorsal has five interradial and five
radial ridges. No cirri are present. As in the smaller of the two other specimens the
radials are visible and are very flat. The radials and the IBr series in this specimen
agree almost exactly with those of the smaller of the other two. The IIBr series are 2.
The form of the IIBr series and of the first two brachials, and especially of the first
syzygial pair, are approximately as in the larger of the two others. There are no
IIIBr series. There are 15 arms about 20 mm. long. The first syzygy is between
brachials 3 + 4 and the second is between brachials 17+18.

PI is about 2 mm. long and is composed of 9-12 segments of which those in
the proximal portion are stout and those in the outer half more slender. The first
three segments are broader than long, those succeeding elongated, the terminal shorter
again. In general P1 resembles the same pinnule in the two other specimens. Pj is
about half as long as PI with 5 or 6 segments of which the first-third are markedly
stouter than those following. The pinnules succeeding are of the same form and
length but are composed of fewer segments, as is the case with the corresponding
pinnules in the other specimens; there is the same leaflike expansion of the lower
segments.

The disk is not visible; the color in alcohol is brownish white.

Hartlaub pointed out that Horaeometra duplex is especially noteworthy on account
of its relatively small size, his largest specimen, with the arms only 45 mm. long, hav-

190 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ing well-formed gonads. He pointed out that no less than four of the species assigned
by Carpenter to the Spinifera group belong also to the Basicurva group.

Localities. — Albatross station 2342; off northern Cuba (lat. 23°10'39" N., long.
82°20'21" W.); 367 meters; coral; January 19, 1885 (2, U.S.N.M., 34560, 34592).

Albatross station 2346; off northern Cuba (lat. 23°10'39" N., long. 82°20'21" W.);
366 meters; coral; January 20, 1885 (1, U.S.N.M., 22673).

Atlantis station 2999; Bahia de Matanzas, Cuba (lat. 23°10' N., long. 81°29' W.);
265-420 meters; March 17, 1938 [H. L. Clark, 1941].

Atlantis station 3303; off Playa Baracoa, Habana Province, Cuba (lat. 23°05' N.,
long. 82°33' W.); 475 meters; March 23, 1939 [H. L. Clark, 1941].

Atlantis station 3437; off the north coast of Santa Clara Province, Cuba (lat.
23°05' N., long. 79°32' W.); 475 meters; May 2, 1939 [H. L. Clark, 1941].

Atlantis station 3465; Bahia de Matanzas, Cuba (lat. 23°09' N., long. 81°27' W.);
320 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3466; Bahia de Matanzas Gat. 23°09' N., long. 81°27'30" W.);
366 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3467; Bahia de Matanzas (lat. 23°11'30" N., long. 81°26' W.);
393 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3478; Bahia de Matanzas (lat. 23°09' N., long. 81°27'30" W.);
439 meters; May 11, 1939 [H. L. Clark, 1941].

Atlantis station 3479; Bahia de Matanzas (lat. 23°10' N., long. 81°26'30" W.);
384 meters; May 11, 1939 [H. L. Clark, 1941].

Atlantis station 3480; Bahia de Matanzas (lat. 23°10' N., long. 81°28' W.); 366
meters; May 11, 1939 [H. L. Clark, 1941].

Atlantis; off Playa Baracoa, Habana Province, Cuba; 475 meters (=station 3303)
[H. L. Clark, 1941].

Atlantis; off Caibarien, Santa Clara Province, Cuba; 475 meters (= station 3437)
[H. L. Clark, 1941].

Atlantis; off the north coast of Cuba; about 183 meters [H. L. Clark, 1941].

Caroline station 38; west of Puerto Rico (lat. 18°10' N., long. 67°46' W.); 402
meters; February 10, 1933 (1, U.S.N.M., E. 5251).

Blake station 269; off Milligan's Key, St. Vincent (lat. 13°07/55" N.,long.61°05'36"
W.); 227 meters; bottom temperature 14.17° C.; coral; March 3, 1879 [von Graff,
1883, 1884; P. H. Carpenter, 1888] (106, M.C.Z., 305, 307, 308).

Blake station 232; off St. Vincent (lat. 13°06'45" N., long. 61°06'55"W.); 159
meters; bottom temperature 16.67° C.; coral; February 21, 1879 [P. H. Carpenter,
1888; Hartlaub, 1912] (28, M.C.Z., 306).

IBlake station 249; off Grenada (lat. 11°48'15" N., long. 61°48'45" W.); 479
meters; bottom temperature 8.3° C.; coarse sand; February 27, 1879 [P. H. Carpenter,
1888; Hartlaub, 1912].

Caribbean Islands and Straits of Florida; 161-479 meters [P. H. Carpenter, 1888].

Geographical range. — From northern Cuba eastward and southward along the
Antillean Chain to St. Vincent and ?Grenada.

Bathymetrical range. — From 159 to 479 meters; the average of 18 records is 370
meters.

Thermal range. — From 8.3° to 16.67° C.

A MONOGRAPH OF THE EXISTING CRINOID8 191

History. — This species was first mentioned under the name Antedon duplex, a
nomen nudum, by Prof. Ludwig von Graff who in 1883 listed it, as a host for myzos-
tomes, from off St. Vincent in 124 fathoms (Blake station 269). Professor von Graff
republished this notice in 1884.

Dr. P. H. Carpenter in the Challenger report upon the comatulids published in
1888 did not formally describe this species, though he mentioned it several times.
He listed it as one of the few species having either 10 or more than 10 arms with the
IIBr series 2, and inserted it in his key to the species of the Spinifera group with the
characters over 30 cirrus segments, the later ones spiny; P! as long as or longer than P2;
centrodorsal rounded, the cirri without definite arrangement; 30-40 cirrus segments;
the IBr axillaries long; and the lower segments of the genital pinnules expanded. He
said that Antedon (Stiremetra) lusitanica differs from duplex in the shape of the axillaries
and in the unmodified character of the genital pinnules, so far as can be determined
from the condition of their fragmentary remains. He gave as the range "Caribbean
Islands; Straits of Florida; 88-262 fathoms."

In 1895 Dr. Clemens Hartlaub discussed the systematic and bathymetrical rela-
tionships of this species, on the basis of the information given in the Challenger report,
and compared it with his new species Antedon (Thalassometra) agassizii.

In 1905 Dr. Wilhelm Minckert discussed the syzygies and arm division of Antedon
duplex, his specimens, received from Hartlaub, presumably having come from Blake
station 232.

In my first revision of the old genus Antedon published in 1907 duplex was assigned
to the new genus Thalassometra. In a revision of the family Thalassometridae pub-
lished in 1909 I listed Antedon duplex among the species I was unable to place definitely
because of lack of material for comparison. In his memoir on the comatulids of the
Blake expeditions published in 1912 Hartlaub discussed this species in detail and figured
it on the basis of three specimens from station 232. In my memoir on the crinoids of
the Siboga expedition published hi 1918 I listed Horaeometra duplex and gave the
synonymy. I also inserted the new species koehleri hi my key to the species of Cosmio-
metra, basing this new species on Hartlaub's figures 2 and 4 on plate 3, and 5 and 10 on
plate 14, identified by him as duplex. These figures really represent Horaeometra
duplex and not a species of Cosmiometra. In 1923 in my memoir on the crinoids of the
Ingolf expedition I included Horaeometra duplex and gave the geographical and bathy-
metrical ranges.

In 1941 Dr. Hubert Lyman Clark recorded 42 specimens of Horaeometra duplex
from 9 Atlantis stations and some other localities off the coast of Cuba hi 145-240, and
about 100, fathoms.

Family CHARITOMETRIDAE A. H. Clark

Basicurva group (in part) P. H. CARPENTEB, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p.
102 (Antedon basicurva, A. incisa, A. tuberosa, A. parvipinna, A. flexilis, and A. aaileata);
Journ. Linn. Soc. (Zool.), vol. 21, 1889, p. 308 (species compared with Antedon [Pontiometra]
andersonf). — HARTLAUB, Nova Acta Acad. German., vol. 58, No. 1, 1891, p. 12 (diagnosis;
range; 20 species), p. 14 (characteristic of the deep sea); Bull. Mus. Comp. Zool., vol. 27,
No. 4, 1895, p. 130 (revision, and arrangement of the included species according to
depth), p. 136 (structural position). — BATHER, Geol. Mag., dec. 4, vol. 3, 1897, p. 120 (pin-
nules compared with those of Millericrinus recubariensis) . — GRIEG, Bergens Mus. Aarbog for
1903 (1904), No. 5, p. 35. — BELL, Marine investigations in South Africa, vol. 4, 1905, p. 139

192 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

(description of a new species, Antedon capensis [= Tropiometra carinata], in reality a member
of Carpenter's Milberti group). — MINCKERT, Arch. Naturg., Jahrg. 71, vol. 1, 1905, p. 207. —
A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, pp. 127, 128 (new species described); Smith-
sonian Misc. Coll., vol. 50, pt. 3, 1907, pp. 343, 344 (characters differentiating this group not
diagnostic), p. 345 (heterogeneous nature of the group), p. 348 (species with unplated disk and
ambulacra assigned to Nanometra, gen. nov.), p. 359 (larger part of species included in Thalas-
sometra, gen. nov.), p. 361 (most of the species not included in Thalassomelra fall into Chari-
tometra, gen. nov.); Proc. U. S. Nat. Mus., vol. 36, 1909, p. 365 (included by Hartlaub and
Minckert in a section of Antedon with side and covering plates, though some species are without
them) .

Acoela group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 131
(Antedon acoela only; A. discoidea belongs to the Calometridae) . — HARTLAUB, Nova Acta Acad.
German, vol. 58, No. 1, 1891, p. 12 (diagnosis; range; 2 species), p. 14 (characteristic of the
deep sea) ; Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 136 (structural position). — MINCKERT,
Arch. Naturg., Jahrg. 71, vol. 1, 1905, p. 207.— A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33,
1907, p. 128 (description of new species in this group) ; Smithsonian Misc. Coll., vol. 50, pt. 3,
1907, p. 343 (characters differentiating this group not diagnostic), p. 362 (Poecilometra, gen.
nov., includes part of the species), p. 363 (Calometra, gen. nov., includes part of the species).

Spinifera group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p.
211 (Antedon flexilis, A. patula, A. robusta, A. pourtalesi, and A. brevipinna; A. macronema
belongs to the Ptilometridae and A. quinquecostata, A. spinifera, A. duplex, A. lusitanica, and
A. compressa to the Thalassometridae) . — MINCKERT, Arch. Naturg., Jahrg. 71, vol. 1, 1905, p.
207; for further references see p. 1.

"ranulifera group (in part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p.
239 (Antedon angusticalyx, A. inaequalis, A. granulifera, and A. distincta; A. mullispina and A.
porrecta belong to the Thalassometridae); Journ. Linn. Soc. (Zool.), vol. 21, 1889, p. 308 (species
compared with A. [Pontiometra] andersoni). — HARTLAUB, Nova Acta Acad. German., vol. 58,
No. 1, 1891, p. 13 (diagnosis; range; 6 species). — BELL, Proc. Zool. Soc. London, 1894, p. 398
(description of Antedon inopinata, sp. nov. [= Himerometra robustipinna, Himerometridae]). —
HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 136 (structural position). — GRIEG,
Bergens Mus. Aarbog for 1903 (1904), No. 5, p. 85. — MINCKERT, Arch. Naturg., Jahrg. 71,
vol. 1, 1905, p. 207.— A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, pp. 343, 344
(characters differentiating this group not diagnostic), p. 359 (one species included in Thalas-
sometra, gen. nov.), p. 361 (most of the species not included in Thalassometra fall in Charitometra,
gen. nov.). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, pp. 285, 286.

Brevipinna group MINCKERT, Arch. Naturg., Jahrg. 71, vol. 1, 1905, p. 225. — A. H. CLARK, Smith-
sonian Misc. Coll., vol. 50, pt. 3, 1907, p. 344 (history and definition) ; Vid. Medd. Nat. Foren.
K0benhavn, 1909, p. 146 (criticism; in reality non-existent).

Savignyi group (in part) BELL, Marine investigations in South Africa, vol. 4, 1905, pp. 140, 141
(descriptions of two new species, Antedon sclateri and A. magnicirra).

Thalassometridae (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136; Proc. U. S.
Nat. Mus., vol. 34, 1908, p. 211.

Charitometrinae A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 2 (definition and com-
parisons), p. 18 (revision of the included genera); Vid. Medd. Nat. Foren. K0benhavn, 1909,
p. 146 (variation in the IIBr series in West Indian species); Mem. Australian Mus., vol. 4, 1911,
p. 728 (raised to family rank); Journ. Washington Acad. Sci., vol. 5, No. 4, 1915, pp. 126-134
(phylogenetical and paleontological significance of the bathy metrical range).

Charitometridae A. H. CLARK, Mem. Australian Mus., vol. 4, 1911, p. 728 (Charitometrinae raised to
family rank) ; Crinoids of the Indian Ocean, 1912, p. 6 (number of East Indian genera also repre-
sented in the Atlantic, number represented in the Atlantic by closely allied genera, and number
confined to the East Indies; number of East Indian species), p. 10 (greatly developed in Japan),
p. 11 (occurs both east and west of Ceylon), p. 12 (represented in the Red Sea region by Pachylo-
metra, in the southeast African region by the same), p. 13 (East Indian and corresponding West
Indian genera), p. 14 (characterisitc of the Intermediate fauna, but one species comes within 30
fathoms of the surface), p. 24 (range in detail; closely parallels the range of the Thalassometridae,

A MONOGRAPH OF THE EXISTING CRINOIDS 193

average depth about the same, but no species descend so deep or come so near the surface), p. 42
(raised to family rank from a subfamily), pp. 45, 49, 51, 53 (in keys), p. 60 (key to the included
genera). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 286 (discussion). —
SPRINGER and CLARK, Zittel- Eastman's Paleontology, 1913, p. 236 (in the Oligophreata).— A. H.
CLARK, Bull. Inst. Oce'anographique, Monaco, No. 294, 1914, pp. 7, 8 (temperature relations);
Journ. Washington Acad. Sci., vol. 4, No. 19, 1914, pp. 559-563 (correlation of geographical and
bathymetrical ranges); No. 20, 1914, p. 582 (relation to temperature of habitat); Internat. Rev.
gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4 and following (Atlantic and corresponding Indo-
Pacific genera) ; Die Crinolden der Antarktis, 1915, p. 132 (covering plates compared with those in
the Heliometrinae), p. 164 (represented in South Africa by Pachylometra sclateri); Amer. Journ.
Sci., vol. 40, 1915, p. 67 (detailed philosophical discussion of bathymetrical range); Smithsonian
Misc. Coll., vol. 65, No. 10, 1915, pp. 43 and following (phylogenetical study) ; Unstalked crinoids
of the Siboga Exped., 1918, p. 171 (key to the included genera); Journ. Washington Acad. Sci.,
Vol. 9, No. 5, 1919, p. 136 (arm bases compared with those of Holopus) ; Univ. Iowa Studies in Nat.
Hist., vol. 9, No. 5, 1921, p. 12 (represented in the West Indies) ; Smithsonian Misc. Coll., vol. 72,
No. 7, 1921, pp. 3, 13. — GISL£N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, voL 5, No. 6, 1922, pp.
10, 119. — A. H. CLARK, The Danish /n0oZ/-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40. — GISL£N,
Zool. Bidrag Uppsala, vol. 9, 1924, p. 19 (arm structure), pp. 42, 44, 73, 80, 84, 85, 88, 90, 94, 100,
231, 239, 280, 284; Vid. Medd. Dansk Naturh. Foren. K0benhavn, vol. 83, 1927, pp. 33, 38;
Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, pp. 8, 9. — A. H. CLARK, Journ. Linn. Soc. (Zool.), vol.
36, No. 249, April 1929, p. 655.— GISL£N, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93.
October 26, 1933, pp. 481, 482. — A. H. CLARK, Treubia, vol. 14, livr. 2, December 1933, p. 214. —
GISL£N, Kungl. Fysiograf. Sallsks. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20. 22, 23.—
A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936, 1937, pp. 101,
103. — GISL£N, Kungl. Svenska Vet.-Akad. Handl., ser. 3, vol. 17, No. 2, October 3, 1938, pp. 4,
18.— H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 9.— A. H. CLARK,
Bernice P. Bishop Mus. Bull. 195, 1949, p. 75.

Charitometriden A. H. CLARK, Die Crinolden der Antarktia, 1915, p. 192 (species and genera of this
family especially characteristic of the Intermediate fauna).

Diagnosis. — -A family of the superfamily Tropiometrida in which the ventral
perisome of the pinnules is protected by well-developed and conspicuous side and
covering plates easily visible with a hand lens; PI and P2 are similar (in small species
P2 may be like P3), of about the same length as the following pinnules, sometimes some-
what longer or shorter, but more slender and flexible and composed of a large number
of short segments; and the cirri are short, stout, and strongly curved, composed of
usually less than 25 segments of which the outer are little, if at all, shorter than the
earlier and bear no dorsal processes though they may be carinate or rise into low
broadly rounded tubercles at the distal end; there is no transition segment and all the
segments are similarly dull in color.

Geographical range. — From southern Japan, the Hawaiian Islands, Fiji, the Ker-
madec*Islands, the Sahul Bank, and Timor westward to east Africa, from Sokotra
southward to East London; St. Helena; from the Yucatan Bank, the Florida Keys,
northern Cuba, and the southern Bahamas eastward and southward to Barbados and
Grenada.

Bathymetrical range. — From 55 to 2,194 meters.

Thermal range.— From 4.17° to 18.20° C.

Remarks. — Because of the singularly uniform structure of all the species in this
family, particularly the similarity of the oral pinnules and of the cirri throughout, the
delimitation of natural genera within the group has proved to be a matter of no little
difficulty. Twelve genera have been established, many of them based on characters

843803 — 50 14

194 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

that have proved to be unreliable, some of them of at most only specific significance,
some even inconstant within a single species.

The first genus established, Charitometra (genotype Antedon incisa), was essen-
tially the equivalent of the family Charitometridae as now understood, except for the
exclusion of the species of the genus Poecttometra (genotype Antedon acoela) established
at the same time, and the inclusion of Antedon compressa and A. orion which are now
assigned to the genus Parametra in the family Thalassometridae. The genus Poectto-
metra was separated on the basis of the concave sides of the elements of the IBr series,
their produced and flangelike dorsolateral edges, and the much expanded genital pin-
nules. In separating Poecilometra from Charitometra I was influenced by the fact
that Carpenter had made his Antedon acoela the type of a special group, the Acoela
group, in which he also included Antedon discoidea, a species of the family Calometridae.
He defined the Acoela group as having "The rays not flattened laterally. Pinnule
ambulacra well plated."

In 1909 I established the subfamily Charitometrinae and gave a key to the seven
included genera, five of which were diagnosed for the first time. The first division
included genera in which the IBr series and lower brachials have produced or everted
edges forming a thin flangelike border. Poecilometra was distinguished by having the
dorsal edges also produced, the genital pinnules greatly and abruptly expanded, and
the IBr series and brachials rounded dorsally without ornamentation. In Glyptometra
(genotype Antedon tuberosa) the IBr were said to have only the dorsolateral edges
produced, the genital pinnules very regularly expanded and evenly tapering, and the
IBr series and lower brachials with the dorsal surface rugose or tubercular. The
second division included genera in which the IBr series and lower brachials do not have
the dorsolateral edges produced. In one section the included genera have the third
and fourth segments of the genital pinnules broad and nearly flat on the outer side, but
the fifth segment smaller. This section included Strotometra (genotype Antedon hep-
burniana) with less than 12 cirrus segments and the IBr series and arm bases diverging
at a wide angle, and Charitometra with more than 15 cirrus segments and the IBr
series and arm bases diverging at a relatively small angle. The other section included
genera with the genital pinnules evenly and only slightly expanded. There were
three divisions of this section. In one the lower pinnules were said to be twice as long
as the middle pinnules; this included Crinometra (genotype Comatula brevipinna).
In the other section the lower and middle pinnules were said to be of approximately
the same length. This section included Pachylometra (genotype Antedon distincta) in
which the cirri were said to be large and stout with 18 or more segments, and Chlo-
rometra (genotype Antedon garrettiana) in which the cirri are weak and slender with
16 or fewer segments.

In his excellent memoir on the comatulids of the Blake Expedition published in 1912
Dr. Clemens Hartlaub had considerable difficulty with the interrelationships of the
species of this family. He used Carpenter's classification instead of my new classifica-
tion then in process of development for the reason, as he told me, that he was simply
completing a work begun by Carpenter and therefore felt himself bound to follow Car-
penter's original plan. He identified two specimens from Blake station 157 as Antedon
angusticalyx, but said that they stand between A. angusticalyx and A. inaequalis.
But in the larger of these specimens PD is 11 mm. long with about 30 segments, PI is

A MONOGRAPH OF THE EXISTING CRINOIDS 195

6-7 mm. long with 15-18 segments, and the genital pinnules are mostly 5-6 mm. long
with 9-14 segments; these proportions are very different from those of the pinnules of
either angusticalyx or inaequalis, and agree with those of other forms in the genus
Crinometra.

In 1916 I established five new genera (see Part 3, page 58) as follows: Crossometra
(genotype Pachylometra septentrionalis) with the cirri arranged in 10 columns on the cen-
trodorsal and 26-33 arms; Perissometra (genotype Antedon flexilis) with the cirri
arranged in 10 columns on the centrodorsal and 10-20 arms; Monachometra (genotype
Pachylometra Jragilis) with the cirri arranged in 15 columns on the centrodorsal, all
the division series 2, and the division series and first two brachials rising rather sharply
to a blunt keel; Calyptometra (genotype Charitometra lateralis) with the lateral borders
of the elements of the division series and first four brachials strongly everted and with
a blunt median keel, the proximal pinnules somewhat longer and more slender than their
successors, and 10, rarely 11 arms; and Chondrometra (genotype Chlorometra robusta)
with the arms in their outer portion as well as the IBr series and arm bases strongly
compressed laterally and rising dorsally into a rooflike keel, with 10 arms, with the cirri
in 5 or 10 columns, and with the proximal pinnules about as long as those succeeding.

In my memoir on the unstalked crinoids of the Siboga Expedition published in 1918
I recognized the genera Crinometra, Strotometra, Poecilometra, Charitometra, Chondro-
metra, Glyptometra, Crossometra, Perissometra, Monachometra, Pachylometra, Calypto-
metra, and Chloromeira. A key to these was given, using the characters given above.

In his paper on the crinoids collected by Dr. Th. Mortensen in Japan Prof. Torsten
Gislen pointed out some inconsistences in my classification. He said it seemed to him
very doubtful whether Glyptometra and Perissometra can be maintained as sharply
differentiated genera. He noted that as at first diagnosed Glyptometra included some
species now referred to Perissometra, a later genus. He remarked that the chief
difference between Perissometra and Glyptometra is said to be that the former has on the
brachials "a blunt median carination . . . never a low sharp median keel . . .
proximal and distal borders of the ossicles of the division series and the lower brachials
never everted and standing up at right angles to the general surface of the segments."
But he noted that I said Perissometra patida has the "ossicles of the division series and
brachials each with a broad low inconspicuous keel which persists to the ends of the
arms; distal edges of the discoidal brachials beyond the second prominently and abruptly
everted, of the more distal triangular brachials produced and overlapping"; and I also
said of P. lata that "the median portion of the ossicles of the IBr series and first two
brachials is abruptly raised into an irregular rounded tubercle . . . the proximal
and distal borders are more or less irregularly crenulate." The difference in the orna-
mentation between Glyptometra as typified by G. tubejrosa and Perissometra as represented
by P. patula and P. lata is really strongly marked, though it was perhaps poorly de-
scribed. Nevertheless, his point is well taken, and the difference in ornamentation
affords no good grounds for generic separation. He quite rightly remarked that the
limit between the two genera is obscure, but suggested that perhaps one should, how-
ever, be able to retain the two genera in a somewhat altered sense ; G. tuberosa is said to
have the cirrus segments provided with a dorsal keel, while on the other hand the species
of Perissometra usually have no dorsal spine. With such a limitation, he said, tuberosa

196 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and patula must be referred to Glyptometra, and so must lata, crassa, and perhaps also
other species now referred to Perissometra.

In 1927 Gislen recorded specimens of Perissometra aranea, which he had described
in 1922, and described P. carinata and Monachometra mortenseni, all three of which are
based upon specimens of Parametra orion, a species of the family Thalassometridae.
In 1928 after examining the Challenger material in the British Museum he published
various notes on the classification of the Charitometridae. He said that the genus
Parametra must be referred to the Charitometridae, repeating the error I had made in
my original diagnosis of the genus Charitometra to which I referred Antedon compressa
and A. orion, both species of Parametra. He noted that Carpenter's Antedon distincta,
which I referred to the genus Pachylometra, must be referred to Crossometra, as it has the
cirri arranged in 10 columns. Under Perissometra angusticalyx he said that Perissometra
is indistinctly separated from Crossometra; all Perissometras with the IIBr series 4(3 + 4)
should be referred to Crossometra, leaving in Perissometra 10-armed forms and those with
the IIBr 2 — patula, timorensis, lata, flexilis, and aranea (the last= Parametra orion).
He noted that two widely different forms are included under Perissometra patula. One
specimen with only 10 arms, as is often the case the larger one, has the centrodorsal
discoidal, the cirri stout, arranged in 12 columns, the segments with a dorsal spine and
keel, and a simple opposing spine. In the other, which seems to be the same type as
described and figured by Carpenter, the centrodorsal is sharply conical with the cirri
in 10 columns, the cirrus segments without dorsal spines, the opposing spine forked, and
the brachials collar-shaped; the arms, he said, were very similar to those of his Dio-
dontometra= Chlorometra) , but the arrangement of the cirri is different; the cirrus sockets
are striated, just as in some fossil comatulids. He said that the first type should be
referred to Monachometra. Under Perissometra flexilis he said that the subdivision of
the genus Perissometra into species with more or less than 13 arms is not suitable. Un-
der Monachometra robusta he said that this species, considered by me to be a Peris-
sometra, must be referred to Monachometra. He remarked that Charitometra and
Poecilometra are closely related. The flanges on the proximal pinnules are rather simi-
lar. The difference of the basicurvity is, however, noticeable. He suggested the fol-
lowing differences: (a) Arm bases well separated, Poecilometra; (b) Arm bases flattened
and close to each other, Charitometra. He said that Strotometra parvipinna ought to be
referred to Perissometra and is perhaps the same as his P. aranea.

In conclusion Professor Gislen said he thought it evident from the examples given
that the family Charitometridae is still not satisfactorily subdivided. It seemed to
him that I had laid too much stress on the ornamentation of the arms. He believes
that the cirri offer quite as good or even better differential characters. In many cases
they are exceedingly characteristic, and evidently they are much less subject to varia-
tion than the ornamentation. He said that there are at least two very distinct types of
cirri within the family: (1) Stout cirri lacking dorsal spines, and (2) Slender cirri with
distal dorsal spines. The former may have or lack an opposing spine which is, besides,
often transverse or even bisected. Though in the former case the cirri are devoid of
dorsal spines the segments may possess a faint longitudinal crest. He believed that
by considering these characters we may find it much easier to subdivide the family so
as more correctly to indicate interrelationships.

A MONOGRAPH OF THE EXISTING CRINOIDS 197

In 1933 when describing Crinometra transversa from St. Helena Professor Gisle'n
wrote that when I established the genus Crinometra I distinguished it from the related
genus Pachylometra by the very long proximal pinnules, which should be very strongly
carinate, and by the proportionately short middle and distal pinnules, which were said
to be not quite half as long as P(. The genital pinnules should be more abruptly
expanded than those of Pachylometra. Besides, there should appear in Crinometra
overlapping brachials and usually tuberculation of the basal portions of the arms. He
said that in 1918 I considered the difference in length between the proximal and middle
pinnules, together with the proximal carination of the former, the chief distinguishing
feature between Crinometra and the remaining genera of the Charitometridae. He
said that in fact the overlapping of the brachials, the expansion of the pinnules, and
the tuberculation of the arm bases are so variable or indefinite characters within
Crinometra that they certainly cannot be used for generic characterization. He
remarked that the question is whether the character of the middle pinnules, being not
quite half so long as PI, may be used as a distinguishing mark for Crinometra. When
studying Hartlaub's treatise on the varieties of Crinometra brevipinna (1912) he found
the following statements. In var. elegars PI is 10-12 mm. long, and the middle pinnules
are 7 mm. long; in var. diadema Pt is 8 mm. long, and the middle pinnules are 5 mm.
long. He said he had found the same proportions in a specimen of Crinometra insculpta
borrowed from the Copenhagen Museum that had been identified by me. He noted that,
on the other hand, short middle pinnules may occur in species of Charitometridae that
do not fall in Crinometra, as for instance in Perissometra aranea, P. carinata, and
Monachometra mortenseni. He remarked it is clear that this feature cannot be used
alone for distinguishing Crinometra. But Perissometra aranea, P. carinata, and
Monachometra mortenseni belong not to the Charitometridae but to the Thalas-
sometridae, all three being synonyms of Parametra orion (see page 72). Gisl6n wrote
it might be asked whether the feature of the long proximal pinnules may not be used
together with other distinguishing characters. He said that the carination of the
proximal pinnules may be a rather good character, but in some forms referred to this
genus it is poorly developed and very insignificant, for instance in granuli/era. The
tuberculation in some forms is very characteristic and apparent, but is lacking in others.
He said that therefore either some forms with smooth arm bases should be excluded
from the genus, as C. pulchra, or this feature should not be used as a generic character.
He regarded the tuberculation of the arm bases as of small systematic significance.
He said that the large number of segments in the proximal pinnules, 20-40, as compared
with those of the middle pinnules, 10-15, may be generically important, but similar
conditions seem to occur also in some Pachylometras and Perissometras. But in these
the length of the middle pinnules does not seem to decrease. In this connection he
said it is to be regretted that our knowledge of the proportions of the proximal pinnules
is very scanty, especially as regards the more recently described species.

Since Crinometra transversa, as well as some of the forms of Crinometra previously
known, cannot be separated as a group of species which can possibly be distinguished
from other Charitometridae, he said that either Crinometra must be given up or it must
be provided with an emended diagnosis. The facts seem to speak in favor of the
latter solution, and it may be possible to distinguish the genus in the following manner:
Crinometra is a genus of the Charitometridae in which the centrodorsal is a thick disk;

198 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

the cirri are up to XX, 15-25; the cirrus sockets, in mature individuals, are arranged
in about 15 crowded columns; the IBri is very short; the IIBr series are 2 or 4 (3+4);
the IIIBr series, when present, are 2, developed internally; and the first two brachials
are united by syzygy, at least after a IIBr 4(3+4) series, or a IIIBr series; PI and P2
are the longest pinnules on the arm, with more than 20 segments; the pinnules then
rapidly decrease in length, the middle pinnules being about three-fourths or half the
length of the proximal ones; the genital pinnules are moderately expanded over a
number of segments. He said that within these limits Pachylometra inaequalis must
be included in the genus, and perhaps P. levigata also. He remarked that Pachylometra
distincta, which in 1909 I made the type of Pachylometra, is in reality a Crossometra,
as pointed out by him in 1928; Crossometra therefore becomes a synonym of
Pachylometra.

In reviewing the 13 genera at present accepted in the family Charitometridae it
was found that much confusion existed. Several of the genera were based upon
characters of minor importance, or so variable as to be unreliable and undiagnostic.
These characters were chiefly those found in the arms, especially the type of arm
division and ornamentation; the type of genital pinnules; the length of the oral pinnules;
the distribution of the cirrus sockets ; and the number of cirrus segments. The characters
presented by the details of the cirri were disregarded; they were overlooked because
of the singularly uniform general appearance of the cirri throughout the family.

The number of arms is of little significance. Several genera include only species
with 10 arms, in others the included species may have 10 or more than 10 arms, in
still others the number of arms appears always to be more than 10. In a few genera
the IIBr series are always 2, but in most they are chiefly 4(3+4), more rarely 2, though
hi some individuals all the IIBr series present may be 2. Although in a few species,
as in Glyptometra tuberosa, ornamentation is always present and characteristic, in most
of the species in which it occurs it is highly variable. The extreme is reached in Crino-
metra brevipinna in which some individuals have the most highly developed and com-
plex ornamentation to be found in the family while others are entirely plain. Some-
times the adults will have a characteristic ornamentation though the young are plain.
But strong lateral compression of the arms combined with carination involving the
whole dorsal surface is a reliable feature. The characters presented by the genital
pinnules seem to be reliable. In many species, however, these are variable, the genital
pinnules of some individuals being almost or quite unmodified, of others much swollen.
In individuals of some forms of Crinometra brevipinna the genital pinnules have the
third and fourth segments abruptly expanded as in Strotometra, though the slender
portion beyond these is always much longer than the swollen part. There appears
to be in general a line of demarcation between the species with the cirri in 10 columns
on the centrodorsal and those in which the cirri are in 15 or 5 columns; but in some,
as Glyptometra inaequalis, they may be in either 10 or 15 columns, in some they may
be in 10, 11, or 12 columns, and in others they are in 10 columns in young individuals
and in 15 in the fully grown.

Of the genera heretofore recognized five seem to be without valid significance.
Diodontometra is based upon the new species D. bocki which is a synonym of Antedon
garrettiana, the type species of the genus Chlorometra. Pachylometra as defined is
characterized in part by having the cirri in 15 columns on the centrodorsal, though

A MONOGRAPH OF THE EXISTING CRINOIDS 199

the central column may be wholly or partially absent. After examining an example
of the type species, Carpenter's Antedon distincta, in London, Gisl6n found that the
cirri are arranged in 10 columns. This is the chief character of Perissometra, which
therefore becomes a synonym of it. Pachylometra offers no other features other than
details of ornamentation by which it may be separated from Glyptometra. It there-
fore has no standing. Crossometra differs from Perissometra only in having a greater
number of arms, a wholly unreliable feature. Calyptometra was distinguished mainly
on the basis of the type of ornamentation of the division series and arm bases, a char-
acter of wholly minor significance. The elimination of these genera leaves eight genera
in the family which seem worthy of recognition — Chondrometra, Monachometra, Glypto-
metra, Crinometra, Chlorometra, Charitometra, Poecilometra, and Strotometra.

There seems to be a clear-cut dividing line between the groups of species in which
the genital pinnules taper from the usually more or less broadened earlier segments to
a delicate tip which is always much longer than the gonads, and those in which the
genital pinnules have from two to four segments much broadened, followed by a slender
tip which is shorter than the gonads. In the first category the group with the division
series and arms much compressed laterally and rising evenly dorsally to a ridge, Chon-
drometra, seems to be quite distinct from the group in which the arms are rounded
dorsally, with or without a median raised Hue. In the latter group Crinometra is dis-
tinguished by the relatively long oral and short genital pinnules. In Monachometra
and Glyptometra the oral and middle pinnules differ little or not at all in length. In
Monachometra there are narrow and strongly developed synarthrial tubercles, the Ilbr
series are always 2, and the opposing spine is forked, whereas in Glyptometra the syn-
arthrial tubercles are slightly or not at all developed, the IIBr series are usually 4 (3+4),
sometimes 2, and the opposing spine is single. In the group with the genital pinnules
much swollen at the base and with a short distal portion, the long conical centrodorsal
with the cirri in five double midradial columns, the opposing spine forked, and about
20 arms with the IIBr series 2 distinguishes Chlorometra. In Chlorometra the genital
pinnules are not so abruptly and greatly swollen as they are in the other members of
this group and they may not be swollen at all, though the genital segments are usually
enlarged. The genital pinnules of Chlorometra are very little different from those of
Monachometra, of which Chlorometra should perhaps be regarded as a synonym. Al-
though the arrangement of the cirri in Chlorometra appears to be distinctive, it is prob-
ably no more distinctive than it is in Chondrometra in which the cirri are arranged in
5 midradial columns in C. robusta and C. aculeata, but in 10 columns in C. rugosa. In
the other genera the centrodorsal is hemispherical or discoidal with the cirri in irregular
marginal rows and only 10 arms. The widely divergent arm bases and small size dis-
tinguish Strotometra, while the compressed arm bases of Charitometra are closely ap-
pressed and flattened against each other, those of Poecilometra not in contact and more
or less concave.

Of the eight recognized genera of the Charitometridae, five, Chondrometra, Mona-
chometra, Chlorometra, Poecilometra, and Strotometra, are, as far as is now known, con-
fined to the region between southern Japan and the Lesser Sunda Islands ; one, Chari-
tometra, is known only from the Kermadec Islands and Fiji; one, Glyptometra, covers
the entire range of the family in the Pacific and Indian Oceans, while the closely related
Crinometra represents the family in the Caribbean region and at St. Helena.

200 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The family Charitometridae is closely allied to the family Thalassometridae, but it
represents a more generalized type. The cirri are less specialized, lacking the polished
spine-bearing segments beyond the transition segment characteristic of the Thalas-
sometridae. They may be said to correspond to the cirri of the Thalassometridae as
far as the transition segment, for the penultimate segment often has a polished distal
end like the transition segment of the Thalassometridae. The oral pinnules of the
Charitometridae are usually about as long as the pinnules following, but are more
slender and flexible with much more numerous short segments. They are less modified
than the elongate and basally stout oral pinnules of the Thalassometridae. In the
Charitometridae there are usually two pairs of oral pinnules except hi very small species
while in the Thalassometridae there is only a single pair except in some large species hi
which the second pair may be more or less intermediate. Similarly the genital pinnules
are more generalized than those of the Thalassometridae, being longer and in most cases
more like the distal pinnules. The pinnules in general are not so much stiffened as are
those of the Thalassometridae. In the family Thalassometridae there is an approach
to the Charitometridae hi the genus Parametra in which the cirri have only a few seg-
ments beyond the transition segment, and PI is not greatly longer or stouter than the
pinnules following.

The genera of the Charitometridae do not fall into distinctive groups as do those of
the Thalassometridae, but the first group in this family, with the arms strongly com-
pressed laterally and sharply carinate, finds a parallel hi the genus Chondrometra. The
genera with the genital pinnules abruptly swollen are not so sharply differentiated from
the others as they are in the Thalassometridae.

The family Charitometridae is less widely distributed than the Thalassometridae,
not extending, so far as is now known, to the Aleutian or Galapagos Islands, south-
eastern Australia, or the Crozets, nor does it occur in the Atlantic basin except in the
Caribbean and at St. Helena. Its bathymetrical and thermal ranges are also con-
siderably less.

History. — The species now included in the family Charitometridae were distributed
by Dr. P. H. Carpenter among the Basicurva group, the Acoela group, the Spinifera
group, and the Granulifera group. In 1905 Minckert diagnosed the Brevipinna group
the type species of which is the same as that of Carpenter's Granulifera group. In 1905
Prof. F. Jeffrey Bell described a species of this family, and another of the family Thalas-
sometridae, hi Carpenter's Savignyi group.

In 1907 I segregated all the described species now considered as belonging to this
family in the genera Charitometra and Poecilometra (see Part 3, p. 8). In a paper
published on April 11, 1908, 1 distributed the living comatulids among several families,
assigning the genera Charitometra and Poecilometra to the family Thalassometridae.
In a paper written considerably in advance of this though not published until May 14
(see Part 3, p. 15) the same arrangement is suggested. In 1909 the genera Charitometra
and Poecilometra, together with the new genera Glyptometra, Strotometra, Pachylometra,
Chlorometra, and Crinometra, were segregated as a new subfamily Charitometrinao of
the family Thalassometridae (see Part 3, p. 33). In my memoir on the recent crinoids
of Australia published in 1911 the subfamily Charitometrinae was raised to family rank
and designated as the family Charitometridae.

A MONOGRAPH OF THE EXISTING CRINOIDS 201

KEY TO THE GENERA OF THE FAMILY CHARITOMETRIDAE

a1. Genital pinnules tapering evenly from the usually more or less broadened earlier segments to a

delicate tip, the portion beyond the gonads being much longer than the gonads themselves.
61. Outer portion of the arms strongly compressed laterally, the dorsal surface rising evenly into a
more or less sharp keel in the middorsal line, the keels on each brachial forming a high over-
lapping spine or tubercle; ossicles of the division series and first two brachials with the central
portion elevated, V-shaped in cross section; centrodorsal more or less columnar, the cirrus
sockets in 5 or 10 columns; 10 arms 75-21 1 mm. long (southern Philippines to Timor; 520-1,334

meters) Chondrometra (p. 201)

b*. Outer portion of the arms rounded dorsally, with or without a fine median abruptly raised line.

c1. Oral pinnules little or not at all longer than the middle and distal pinnules.

dl. Ossicles of the division series rising to a prominent narrow, high, smooth, and pointed

synarthrial tubercle the profile of which forms an acute angle; II Br series 2; opposing

spine often or usually forked (Philippine Islands southward to the Kei Islands and the

Sahul Bank; 104-704 meters) Monachometra (p. 208)

d2. Synarthrial tubercles, if present, low and broadly rounded, the profile a broadly rounded
obtuse angle; II Br series 4(3 + 4), occasionally 2; opposing spine never forked (western
Indian Ocean from Sokotra south to East London, South Africa, and eastward to Timor,
the Sahul Bank, the Kermadec Islands, Fiji, and the Hawaiian Islands, and northward

to southern Japan; 55-2,194 meters) Glyptometra (p. 227)

ca. Oral pinnules markedly longer than the very short middle and distal pinnules (from the
Yucatan Bank, the Florida Keys, northern Cuba, and the southern Bahamas eastward
and southward to Barbados and Grenada; also St. Helena; 139-707 meters).

Crinometra (p. 279)

a1. Genital pinnules with from two to four segments much broadened, the broadening ending abruptly
and being succeeded by a slender distal portion shorter than the much swollen and prominent
ovoid gonads; size medium or small, the arms not over 110 mm. and usually less than 100 mm.
in length.

6'. Centrodorsal sharply conical, higher than broad at the base, with the cirrus sockets in 5 columns,
single or partially double, one in the middle of each radial area, the columns being separated
by broad interradial spaces; 14—20 arms 60 mm. long, the IIBR series 2; opposing spine forked

(southwestern Japan to the Bonin Islands; 165-210 meters) Chlorometra (p. 221)

5*. Centrodorsal hemispherical or discoidal, much broader at the base than high, with the cirrus

sockets in irregular marginal rows, not segregated into distinct columns; 10 arms.
c1. Division series and arm bases compressed, their profile making a small angle with the dorso-

ventral axis; at least 15 cirrus segments; larger, the arms 90-110 mm. long.
d1. Ossicles of the division series and lower brachials in close lateral contact, without modified
lateral borders, and broadly and sharply flattened against their neighbors (Kermadec

Islands to Fiji; 1,152 meters) Charitometra (p. 347)

<P. Ossicles of the division series and lower brachials relatively narrow and well separated from
their neighbors, the gap between them more or less completely bridged by a thin flange-
like production of the dorsolateral margin of the ossicles which persists as far as the
fourth or fifth brachials (Celebes to Mindanao; southwestern Japan; 660-1,327 meters).

Poecilometra (p. 354)

c3. Division series and arm bases more or less recumbent, their profile making a large angle with
the dorsoventral axis; not more than 15 cirrus -segments; smaller, the arms not over 75
mm., and rarely over 45 mm., long (Timor and the Kei Islands northward to southwestern
Japan; 180-1,165 [?1, 264] meters) Strotometra (p. 361)

Genus CHONDROMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 128, and

following authors.
Charitomelra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.

202 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Chlorometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22. — F. W. CLARKE
and WHEELER, U. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 195 (inorganic constituents of the
skeleton); Prof. Pap. 102, 1917, pp. 23 and following (same); Prof. Pap. 124, 1922, p. 20 (same).

Chondromelra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (diagnosis;
genotype Chlorometra robusta A. H. Clark, 1911; range; included species). — A. H. CLARK,
Unstalked crinoids of the Siboga-Exped., 1918, p. 172 (in key; range), p. 187 (key to the included
species). — GISLEN, Kungl. Fysiogr. Sallsk. Hand!., new ser., vol. 45, No. 11, 1934, p. 18.

Diagnosis.— A genus of Charitometridae in which the genital pinnules taper evenly
from the more or less broadened earlier segments to a delicate tip, the portion beyond
the gonad being much longer than the gonad itself; the division series and arms are
V-shaped in cross section, rising evenly to a more or less sharp median keel, the keel
on each of the outer brachials forming a high overlapping spine or tubercle; the cen-
trodorsal is conical or columnar with the cirrus sockets in 5 or 10 definite columns;
and the arms are 75-211 mm. long.

Geographical range. — From Timor northward to the southern Philippines.

Bathymetrical range. — From 520 to 1,334 meters.

Thermal range.— From 4.77° to 13.55° C.

Remarks. — The laterally compressed and carinate arms make the species of this
genus easy to recognize. Of the three species herein referred to Chondrometra one,
ru-gosa, seems to be quite distinct; the other two, robusta and aculeata, are separated
on characters that may prove to be due merely to differences in the degree of maturity.

History. — The first known species of this genus, aculeata, was described by Dr.
P. H. Carpenter in 1888 under the generic name of Antedon. In 1907 I transferred it
to the new genus Charitometra. In 1909 I assigned it to the genus Chlorometra of which
the genotype was Antedon garrettiana A. H. Clark, 1907. In 1916 I established the
genus Chondrometra with the genotype Chlorometra robusta A. H. Clark, 1911, and
including also Chlorometra rugosa (a nomen nudum, described in 1918 as Chondrometra
rugosa) and Carpenter's Antedon aculeata.

KEY TO THE SPECIES IN THE GENUS CHONDROMETRA

a1. Centrodorsal very large, truncated conical or more or less columnar, with the cirrus sockets
arranged in 10 regular columns, two, more or less widely separated in the midradial line, in
each radial area; cirri short, one-sixth of the arm length, XXX, 18-19, 35 mm. long; arms 210

mm. long (Celebes southward to the East Timor Sea; 520-871 meters) rugosa (p. 206)

a2. Centrodorsal small or of medium size, sharply conical, with the cirrus sockets arranged in 5 more
or less regular columns, one in the midline of each radial area; cirri longer, from one-fourth to
one-third the arm length.

6'. Size large, the arms 170-211 mm. long; cirri numerous with numerous segments, XX-XXV,
26-28, 55-60 mm. long (southern Philippines southward to the East Timor Sea; 520-1,334

meters) robusta (p. 202)

h2. Size small, the arms 75 mm. long; cirri less numerous with fewer segments, XV, 18, 27 mm.
long (Meangis Islands; 914 meters) aculeata (p. 204)

CHONDROMETRA ROBUSTA (A. H. Clark)

PLATE 19, FIGURE 60
[See also vol. 1, pt. 1, fig. 207, p. 239.]

Chlorometra robusta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 558 (description; Albatross
station 5348; also station 5349; comparison with Ch. aculeata}; Crinoids of the Indian Ocean,
1912, p. 225 (synonymy; locality).

A MONOGRAPH OF THE EXISTING CRINOIDS 203

Chondrometra robusta A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (listed);
Unstalked crinoids of the Siboffa-Exped., 1918, p. 188 (in key; range), p. 189 (references; notes;
station 297), fig. 9, p. 189, p. 275 (listed).

Diagnostic features.— The centrodorsal is sharply conical, as high as broad at the
base, with the cirrus sockets arranged in 5 more or less regular often partially double
midradial columns; the arms are 170-211 mm. long; and the cirri are long with numer-
ous segments, up to 60 mm. in length with up to 28 segments. This may be only the
fully mature form of Ch. aculeata.

Description. — The centrodorsal is long, conical, about 6 mm. broad at the base
and 6 mm, high. The cirrus sockets are confined to the midradial regions where they
are arranged in two very closely crowded converging alternating columns, which merge
and become a single column distally. There are four or five cirrus sockets in each radial
area.

The cirri are stout and very long, XX-XXV, the peripheral with 26-28 segments
from 55 to 60 mm. in length, those near the apex of the centrodorsal with 21 segments
and from 35 to 40 mm. long. The first segment is short and those following increase
in length becoming approximately as long as broad on the sixth and from the eighth
onward about twice as long as broad. The distal dorsal edges of the segments are some-
what thickened, especially in the outer half of the cirri. The penultimate segment is
slightly less in diameter than those preceding. The opposing spine is very small,
terminal. The terminal claw is about as long as the penultimate segment, slender,
and slightly curved. The cirri are moderately compressed laterally.

The 10 arms are 211 mm. long. The arm bases and arms are essentially as in
C. aculeata, but much more rugged. The IBr2 (axillary) has a prominent dorsoventrally
elongate well-rounded tubercle. The second brachial is similar. The following brachi-
als as far as the fourteenth have prominent rounded median tubercles as long as the
segments. After the fourteenth brachial these tubercles become high, thick, overlap-
ping spines, the bases of which occupy the entire dorsal median line of the segments.
Terminally these spines gradually decrease in height and eventually disappear.

The genital pinnules are expanded as in Glyptometra tuberosa.

Notes. — Two smaller specimens were secured with the type just described. One
of these is about the size of the type of C. aculeata, from which it is easily distinguished
by the much longer and more sharply conical centrodorsal and by the dorsal ornamenta-
tion of the arms which, though not so developed as in the fully grown, is yet prominently
marked. The cirrus segments are longer than those of C. aculeata. The other speci-
men has the arms only 55 mm. long. The dorsal ornamentation is only just beginning
to appear, but is already of the type characteristic of the fully grown. The peripheral
cirri are XIV, 19-20, 21 mm. long. The centrodorsal is of the characteristic shape.

The specimen from Albatross station 5349 is large and resembles the type.

Of the specimens from Siboga station 297 one, with the arms about 170 mm. long,
very closely resembles the type; it is very slightly smaller and more slender, and the
median ornamentation of the arms is slightly less pronounced, though of exactly the
same character.

Another specimen is somewhat smaller than the preceding with the dorsal orna-
mentation somewhat less marked; the cirrus sockets are arranged in a single regular

204 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

column in the middle of each radial area, 3, in one case 4, to a column; the surface of
the centrodorsal between the columns is bare and flat.

A very small specimen has the arms 75 mm. long; the centrodorsal, which exactly
resembles that in the preceding except that the interradial areas are slightly convex,
appears unnaturally large. The radials are as large as the IBr^ deep subradial clefts
are present. The longest cirrus is 18 mm. long with 17 segments; the short apical cirri
are 7 mm. long with 1 1 segments, of which the third corresponds to the fourth in the
larger cirri. The longer segments are proportionately slightly longer than in the larger
cirri, and there are only four short distal segments instead of eight or nine. The divi-
sion series and arm bases are obscurely rounded carinate, resembling those of C. aculeata
as figured by Carpenter.

Another very small specimen has the arms 55 mm. long, and the longest cirri 12
mm. long with 13 segments.

All the specimens from this station have the median brachial ornamentation very
slightly less accentuated than in the type. As in the type, the centrodorsal is sharply
conical, and the cirrus sockets are arranged in two closely crowded converging columns
which are confined to the midradial region.

Localities. — Albatross station 5348; Palawan Passage, Philippines; Point Tabonan
bearing S. 89° E., 33.5 miles distant (lat. 10°57'45" N., long. 118°38'15" E.); 685
meters; bottom temperature 13.55° C.; coral and sand; December 27, 1908 [A. H.
Clark, 1911, 1912, 1916, 1918] (3, U.S.N.M., 27505 [type], 35660).

Albatross station 5349; Palawan Passage; Point Tabouan bearing N. 85° E., 45.2
miles distant (lat. 10°54'00" N., long. 118°26'20" E.); 1 ,334 meters ; bottom tempera-
ture 4.77° C.; coral and sand; December 27, 1908 [A. H. Clark, 1911, 1912, 1916, 1918]
(1, U.S.N.M., 35661).

Siboga station 297; East Timor Sea (lat. 10°39' S., long. 123°40' E.); 520 meters;
soft gray mud with brown upper layer; January 27, 1900 [A. H. Clark, 1918] (6,
U.S.N.M., E. 464; Amsterdam Mus.).

Geographical range.— From the southern Philippines southward to the East Timor
Sea.

Bathymetrical range. — From 520 to 1,334 meters.

Thermal range.— From 4.77° to 13.55° C.

History. — This species was originally described in 1911 under the name of Chloro-
metra robusta from a large specimen from Albatross station 5348; notes were given on
two others from the same station, and another large specimen from station 5349.
Chlorometra robusta was listed, with the synonymy and locality, in my memoir on the
crinoids of the Indian Ocean published in 1912. In 1916 Chlorometra robusta was
selected as the type species of the new genus Chondrometra. In my memoir on the
unstalked crinoids of the Siboga Expedition published in 1918 six specimens were re-
corded from station 297; notes on these were given, and the centrodorsal of one of
them was figured.

CHONDROMETRA ACULEATA (P. H. Carpenter)

Antedon aculeata P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, part 60, 1888, p. 128 (de-
scription; Challenger station 214), pi. 23, fig. 3. — HARTLATJB, Bull. Mus. Comp. Zool., vol. 27,
No. 4, 1895, p. 131 (systematic and bathymetrical relationships). — A. H. CLARK, Proc. U. S.
Nat. Mus., vol. 33, 1907, p. 142 (compared with A. [Chlorometra] garrettinana) . — HAMANN,

A MONOGRAPH OF THE EXISTING CRINOIDS 205

Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H.

CLARK, Crinoids of the Indian Ocean, 1912, p. 33 (identity).
Charitomelra aculeata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed). —

Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (type of a nonoceanic group of the genus).
CMorometra aculeata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22 (listed); Proc.

U. S. Nat. Mus., vol. 39, 1911, p. 558 (compared with Ch. robusta) ; Crinoids of the Indian Ocean,

1912, p. 33 (identity), p. 225 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15,

1913, p. 49 (published reference to specimen in the B. M.; Challenger station 214; character of
the brachial carination).

Chondrometra aculeata A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (listed) ;
Unstalked crinoids of the Siboga-Exped., 1918, p. 188 (in key; range).

Diagnostic features. — The centrodorsal is conical, much broader at the base than
high, with the cirrus sockets arranged in 5 more or less regular midradial columns; the
arms are 75 mm. long; and the cirri are 27 mm. long with about 18 segments.

Description. — The centrodorsal is subconical, rather small, with the cirrus sockets
in 5 somewhat irregular midradial columns of 2, 3, or occasionally 4, all the columns
converging at the apex of the centrodorsal.

The cirri are about XV, about 18; most of the segments are longer than broad. In
the figure the first segment is very short, the second is rather more than twice as broad
as long, the third is about twice as broad as long, and those following are from one-third
to one-half again as long as broad. The penultimate segments bear an inconspicuous
opposing spine. The figure shows a cirrus almost straight and tapering slightly in the
distal half; the terminal claw is shown as only slightly curved.

The radials are short and bandlike, marked by occasional grooves and projections.
The IBrt are longer, with flattened lateral borders, but sharply convex in the center
where they rise to meet the posterior projection of the axillaries. The IBr3 (axillaries)
and the first four brachials have a high center and depressed margin like the IBr^ with
sharp lateral edges and flattened sides.

The 10 arms are probably about 75 mm. long. The proximal brachials are rather
short with a sharp mediodorsal line, those following wedge-shaped and more distinctly
carinate so as to overlap. The figure shows the brachials rather sharply carinate with
the dorsal profile rising from the proximal to the distal end so that the profile of the
arm as a whole is strongly serrate.

Syzygies occur between brachials 3+4, again between about brachials 15+16,
and distally at intervals of from 6 to 9 oblique muscular articulations.

PI is rather larger than its successors, the basal segments of which are short and
laterally compressed with a sharp dorsal edge. In the pinnules of the eleventh and
following brachials the third segment and its successors are not expanded but gradually
become longer than broad, and in the terminal third much elongated. Carpenter said
that insofar as he was able to make out without mutilating the specimen the proximal
pinnules have somewhat the trihedral form with flattened outer sides that is charac-
teristic of Charitometra basicurva. Their next successors are altogether different,
however, the third and following segments becoming relatively longer until they
attain the usual elongated shape which is characteristic of the middle and distal pinnules.
But they acquire this shape at about the eleventh or thirteenth brachial so that they
differ from the broad and expanded pinnules in the corresponding part of the arms of
Glyptometra tuberosa.

206 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The disk is concealed. The covering plates of the pinnule ambulacra are supported
on a limestone band which is not distinctly differentiated. The gonads are not pro-
tected by plates. The sacculi are variable, being moderately abundant on some
pinnules and rare on others.

The color in alcohol is light brownish white.

Note. — An examination of the type specimen in the British Museum showed that
this is a small species with a narrow carination. The specimen appears to be a young
individual, and may prove to be a young example of C. robusta.

Locality.— Challenger station 214; off the Meangis Islands (lat. 4°33' N., long.
127°06' E.); 914 meters; bottom temperature 5.44° C.; blue mud; February 10, 1875
[P. H. Carpenter, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1908, 1909, 1911, 1912,
1913, 1916, 1918; Hamann, 1907] (1, B. M.).

History. — -Antedon aculeata was described and figured by Dr. P. H. Carpenter in
his report on the comatulids of the Challenger expedition published in 1888. Its
systematic and bathymetrical relationships were discussed by Dr. Clemens Hartlaub
in 1895, and in 1907 I compared it with a new species, Antedon (Chlorometra') garrettiana.

In my first revision of the old genus Antedon published in 1907 aculeata was
referred to the new genus Charitometra, and in 1908 Charitometra aculeata was men-
tioned as the type of a nonoceanic group within the genus. On the establishment of the
new genus Chlorometra in 1909 aculeata was referred to it. In 1911 I compared Chloro-
metra aculeata with a new species, C. robusta, and in my memoir on the crinoids of the
Indian Ocean published in 1912 Chlorometra aculeata was listed and the synonymy and
range were given. In 1913 I published a short note on the type specimen in the
British Museum. In 1916 aculeata was again transferred to the new genus Chondro-
metra. In my memoir on the unstalked crinoids of the Siboga Expedition aculeata
was included in the key to the species of the genus Chondrometra and the synonymy
and range were given.

CHONDROMETRA RUGOSA A. H. Clark

[See vol. 1, pt. 1, fig. 99, p. 160.]

Chloromelra rugosa F. W. CLARKE and WHEELER, U. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 194
(nomen nudum; inorganic constituents of the skeleton); Prof. Pap. 102, 1917, pp. 21 and following
(same); Prof. Pap. 124, 1922, p. 17 (same).

Chondrometra rugosa A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (listed;
nomen nudum); Unstalked crinoids of the Siboga-Exped., 1918, p. 187 (in key; range), p. 188
(detailed description; station 297), fig. 8, pp. 188, 189 (Albatross station 5656), p. 275 (listed),
pp. 277, 278 (inorganic constituents of the skeleton). — -GiSLEN, Vid. Medd. Dansk Nat. Foren.
K0benhavn, vol. 83, 1927, p. 33 (compared with Perissometra aranea).

Diagnostic features . — The centrodorsal is very large, truncated conical or more or
less columnar, with the cirrus sockets arranged in 10 regular columns, each radial
area with 2, more or less widely separated in the midradial line; the arms are 210 mm.
long; and the cirri are short, about one-sixth of the arm length, 35 mm. long with
18-19 segments.

Description. — The centrodorsal is very large, truncated conical, almost columnar,
9 mm. broad at the base, 4.5 mm. across the slightly convex dorsal pole, and 7 mm,
high interradially. The cirrus sockets are arranged in 10 regular columns, two to
each radial area; the columns in each radial area are almost or quite in contact with

A MONOGRAPH OF THE EXISTING CRINOIDS 207

each other, those of adjacent radial areas separated by a narrow and irregular bare
area which may show a slight narrow rounded ridge in the center. There are three
cirrus sockets to a column.

The cirri are XXX, 18-19, 35 mm. long, short and stout. The first segment is
very short, the second is about twice as broad as long, and those following gradually
increase in length so that the fifth is about as long as the median or distal diameter.
The remaining segments are all about half again as long as the proximal width. The
last five segments decrease rather rapidly in diameter so that the penultimate segment
and the terminal claw are very small. After the first four segments the cirri become
rather strongly compressed laterally; the ends of the segments are slightly swollen and
prominent.

The ends of the basal rays are visible as small tubercles in the angles of the calyx.
The radials are entirely concealed. The IBri are almost concealed, but their
distal portion, which is more or less irregular and tubercular, is visible as a narrow
band just below the axillaries.

The 10 arms are about 210 mm. long. The diameter of the animal at the level of
the seventh brachial is 22 mm. The proximal brachials have the same prominent
median tubercles as those of C. robusta, but they are pointed instead of being rounded
as in that species, and they lean somewhat anteriorly so that they appear as broad
stout overlapping spines. Instead of being perfectly smooth as in C. robusta, the distal
borders of these earlier brachials are thickened and produced. These thickened and
produced borders after the first six or seven brachials bear, in addition to the large
broad median spine the base of which runs backward along the whole median line of
the dorsal surface of the segment, one or two smaller and more pointed spines between
the median spine and the lateral border which do not involve the dorsal surface of the
segments.

Localities— Siboga station 297; East Timor Sea (lat. 10°39' S., long. 123°40' E.);
520 meters; soft gray mud with brown upper layer; January 27, 1900 [F. W. Clarke
and W. C. Wheeler, 1915, 1917, 1922; A. H. Clark, 1916, 1918; Gisten, 1927] (1, Am-
sterdam Mus.).

Albatross station 5656; Gulf of Boni, Celebes; Olang Point bearing N. 67° W.,
14.5 miles distant (lat. 3°17'40" S., long. 120°36'45" E.) ; 871 meters ; bottom tempera-
ture 5.11° C.; gray mud; December 19, 1909 [A. H. Clark, 1918] (1, U.S.N.M., 35702).
Geographical range. — From Celebes to the East Timor Sea.
Bathymetrical range. — From 520 to 871 meters.
Thermal range. — One record, 5.11° C.

History. — This species was first mentioned as Chlorometra rugosa (nomen nudum)
by Prof. Frank Wigglesworth Clarke and Dr. W. C. Wheeler La an analysis of the
inorganic constituents of the skeleton published in 1915 and republished in 1917 and
1922. The fragments analyzed came from the type specimen dredged at Siboga
station 297. On the establishment of the genus Chondrometra in 1916 Chondrometra
rugosa (nomen nudum) was listed among the constituent species. Chondrometra
rugosa was described and figured in my memoir on the unstalked crinoids of the Siboga
Expedition published in 1918 on the basis of a specimen from station 297, and at the
same tune another specimen was recorded from Albatross station 5656; Clarke and

208 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Wheeler's analysis of the skeleton was given in an appendix. In 1927 Prof. Torsten
Gislen compared Chondrometra rugosa with his new species Perissometra aranea.

Genus MONACHOMETRA A. H. Clark

Antedon (part) VON GRAFF, Challenger Reports, Zoology, vol. 20, pt. 61, 1887, pp. 8, 12, and following

authors.

Charitometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.
Pachylometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21.
Perissometra (part) A. H. CLABK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607.
Monachometra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (diagnosis;

genotype Pachylometra fragilis A. H. Clark, 1912; range; included species); Unstalked crinoids

of the St'6o0a-Exped., 1918, p. 173 (in key; range), p. 185.— GISL£N, Vid. Medd. Dansk Nat.

Foren. K0benhavn, vol. 83, 1927, pp. 2, 38; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, pp. 8, 9;

Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.
Monachomera PRESTON, Zool. Record for 1924, 1925, p. Echin. 27.

Diagnosis. — A genus of Charitometridae in which the genital pinnules taper evenly
from the usually more or less broadened earlier segments to a delicate and slender tip, the
portion beyond the gonads being much longer than the gonads themselves; the outer
portion of the arms is rounded dorsally, sometimes with a slightly raised broad median
line; the oral pinnules are of about the length of the pinnules following, often slightly
shorter; the ossicles of the division series rise to a prominent, narrow, high, smooth, and
more or less pointed synarthrial tubercle the profile of which forms a distinct and often
acute angle; the IIBr series are 2; there are 10-21 arms 90-250 mm. long; the cirri are
arranged in 10 or 15 columns on the centrodorsal; and the cirri have 17-31 segments with
the opposing spine often bifurcate.

Geographical range.— From the northern Philippines southward to the Kei Islands.

Bathymetrical range. — From 104 to 704 meters.

Thermal range.— Two records, 7.2° and 15.0° C.

Remarks. — The genus Monachometra as here understood includes, in addition to
M. fragilis the type species, M. patula, M. robusta, and M. flexilis, all of which were
previously placed in the genus Perissometra. Gislen in 1928 suggested that patula,
should be referred to Monachometra, and at the same time definitely assigned robusta
to that genus.

The species of Monachometra are most readily distinguished from those of Glypto-
metra by the smoothness of the division series and arm bases combined with the rather
prominent synarthrial tubercles, and the occurrence of IIBr 2 series only.

Monachometra does not differ essentially from the earlier genus Chlorometra (—Dio-
dontometra Gislen) with which possibly it should be combined.

History. — -Monachometra was established in 1916 with the genotype and only species
Pachylometra fragilis which had been described in 1912. Gislen discussed the genus hi
1927 and described a second species, M. mortenseni (=Parametra orion). In 1928 he
discussed the genus at greater length tentatively adding Carpenter's Antedon patula
and definitely adding Carpenter's Anteden robusta.

KEY TO THE SPECIES IN THE GENUS MONACHOMETRA

a1. Brachials in the proximal portion of the arms with prominently raised distal edges; 10-21 arms 90-
190 mm. long (Philippines to the Kei Islands and the Sahul Bank; 104-385 meters).

patula (p. 209)
aj. Brachials in the proximal portion of the arms with unmodified distal edges.

A MONOGRAPH OF THE EXISTING CRINOIDS 209

6'. Centrodorsal columnar or slightly tapering, with the cirrus sockets arranged in 10 columns, the
midradial lines bare; cirri with 20-25 segments; 10-13 arms about 175 mm. long (Kei Islands;

256 meters).- flexilis (p. 213)

b2. Centrodorsal low, flattened hemispherical or discoidal, with the cirrus sockets arranged in 15

crowded and slightly irregular columns.

c1. Large, with 12-17 arms up to 250 mm. long; cirri with up to 31 segments, up to 70 mm. long
(northern Celebes southward to the Kei Islands, the Sahul Bank, and Timor; 256-520

meters) robusta (p. 216)

c1. Smaller, with 19 arms 145 mm. long; cirri with 17-20 segments (northern Philippines to the
Halmahera Sea; 118-704 meters) ...fragUis (p. 219)

MONACHOMETRA PATUI.A (P. H. Carpenter)

PLATE 20, FIGURE 61

Antedon palula P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, part 60, 1888, p. 219 (de-
scription; Challenger station 192), pi 43. — BELL, Journ. Linn. Soc. (Zool.), vol. 24, 1894, p. 341
(in part; Sahul Bank), pi. 24, figs. 2-6. — HAMANN, Broun's Klassen und Ordnungen des Tier-
Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — A. H. CLARK, Crinoids of the Indian Ocean, 1912,
p. 34 (identity). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 309 (in Spinifera
group; history). — A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 85 (of Bell =
P. patula + robusta).

Charitometra palula A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed).

Pachylometra patula A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed); Proc.
U. S. Nat. Mus., vol. 39, 1911, p. 557 (Albatross station 5356); Mem. Australian Mus., vol. 4, 1911,
p. 795 (synonymy; Sahul Bank); Crinoids of the Indian Ocean, 1912, p. 34 (identity), p. 219
(synonymy; localities); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 48 (published references
to specimens in the B. M.; Challenger station 192; Sahul Bank). — F. W. CLARKE and WHEELER,
U. S. Geol. Surv. Prof. Pap. 90-D, 1914, pp. 33 and following (inorganic constituents of the
skeleton); Prof. Pap. 102, 1917, pp. 20 and following (Albatross station 5036; same); Prof. Pap.
124, 1922, p. 17 (same).

Perissomctra patula A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. 176 (in key; range), p. 179 (references). —
GISLEN, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 83, 1927, p. 35; Ark. Zool., vol. 19,
No. 32, Feb. 20, 1928, p. 8, No. 36 (2 widely different forms under this name; notes); Kungl.
Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20.

Diagnostic features. — The brachials in the proximal portion of the arms have
prominently raised distal edges; the Centrodorsal is subconical, flattened at the apex,
with the cirrus sockets arranged in 10 columns; the 10-21 arms are 90-190 mm. long;
and the cirri have about 20 segments.

Description. — The Centrodorsal is subconical and flattened at the apex, with short
and broad interradial processes at the ventral angles. The cirrus sockets are arranged
in 10 columns, 3 or 4 in each column, the columns in each radial area being in close
apposition interradially but separated in the midradial line.

The cirri are about XXX, 20 ; the segments are stout and smooth, mostly longer than
broad, the longest from slightly longer than broad to half again as long as broad; they
are somewhat compressed laterally and have a sharp dorsal keel.

The radials are not visible. The IBri are short, closely appressed laterally, and
almost V-shaped in lateral view. The IBr2 (axillaries) are widely rhombic with a large
rounded posterior projection which is more or less tubercular in character. The IIBr
series are 2. The IBr series, IIBr series, and first three or four brachials have sharp
lateral edges and flattened sides. The surface of the elements of the IIBr series and of
the lowest brachials rises to a more or less distinct tubercular projection.

210 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The 20 arms are about 175 mm. long and are composed of about 160 brachials, of
which the fourth and following are short and nearly oblong, their surface rising con-
siderably from the proximal to the distal ends, which stand up rather prominently.
Beyond the fifteenth the brachials are more triangular, with a median ridge, and overlap
slightly.

Syzygies occur between brachials 3+4, again from between brachials 19 + 20 to
between brachials 21 + 22, and distally at intervals of from 5 to 9, usually 7 or 8, oblique
muscular articulations.

PI is about 8 mm. long and consists of about 25 short segments the lowest of which
are broad and rather sharply flattened. P2 is a trifle longer and stouter with a smaller
number of larger segments. In the next following pinnules the segments gradually
increase in size and become more carinate, the third-fifth being the broadest ; but they
do not become longer than broad until some way out on the arm. The genital pinnules
have a covering of small plates with the sacculi scattered upon them, and the ambulacra
of the later pinnules have well differentiated side plates with intervening sacculi.

The disk is 10 mm. hi diameter and is thickly plated, as are the arms, both along
the ambulacra and in the intermuscular spaces.

The color in alcohol is whitish brown, the disk darker.

Notes. — Professor Gislen noted that the Challenger specimens in the British Museum
represent two widely different forms.

In the first form the centrodorsal is discoidal; the cirri are stout and are arranged
in 12 columns, and have a dorsal spine and keel and a simple opposing spine. He
remarked that one specimen with only 10 arms is, as is often the case, the larger one.
This form, he said, should be referred to Monachometra.

In the second form the centrodorsal is sharply conical; the cirrus sockets are
striated as hi some fossil comatulids. The cirri are hi 10 columns without dorsal
spines and with a double opposing spine. The brachials are collar shaped. He said
that the arms are very similar to those of Diodontometra, but the arrangement of the
cirri is different. He noted that this seems to be the type described and figured by
Carpenter.

Of the three specimens from Albatross station 5356 one has 14 arms about 170
mm. long and the cirri XXII, 19-22, about 30 mm. long, with a single large and promi-
nent opposing spine; another has 16 arms about 170 mm. long and the cirri XX, 18-20,
30-33 mm. long with the opposing spine large and prominent and usually forked at
the tip; and the third has 20 arms and the cirri XXV, 17-22, 30-37 mm. long with
the opposing spine single.

One of the two specimens from the Danish Expedition to the Kei Islands station
3 has 20 arms 115 mm. long, with ten IIBr 2 series; the longest cirri are 32 mm. long
with 19-20 segments. The other specimen from station 3 has 20 arms 160 mm. long.

The three specimens from the Danish Expedition to the Kei Islands station 3
may be described as follows.

The centrodorsal is stout, conical, not so high as broad at the base, with the
cirrus sockets arranged in 10 crowded columns of 2 or 3 each.

The cirri are XXV, 18-20, long and stout, 35 mm. long. The first segment is
very short, the third is half again as broad as long, the fourth-sixth or -seventh are
half again as long as broad, and those following are slightly shorter, but the last two

A MONOGRAPH OF THE EXISTING CRINOIDS 211

are slightly longer again. The dorsal surface of the segments in the outer half of the
cirri is faintly subcarinate. The penultimate segment is nearly or quite half again as
long as broad, slightly narrower than the segment preceding, with the dorsal and ven-
tral profiles parallel. The opposing spine is terminal, directed obliquely forward,
and forked. The terminal claw is about as long as the penultimate segment, rather
stout basally and moderately curved.

The ends of the basal rays are visible as large rhombic tubercles in the interradial
angles, which almost or quite separate the radials. The radials are concealed except
for the distal border, which is much swollen and forms a chevron-shaped band just
above the margin of the centrodorsal, which has a slight tubercular swelling in the
middle, and sometimes another on either side of this. The IBr, are extremely short,
forming a swollen chevron-shaped band similar to that formed by the radials, but
somewhat wider. The center of this band is swollen into a broad low tubercle, and the
lateral ends are abruptly produced and sometimes swollen, meeting those of the ad-
jacent IBri. The lateral distal angles are rounded. The IBr2 (axillaries) are rhom-
bic, twice as broad as long. The proximal half is raised into a broad well-rounded
tubercle. Below the lateral angles there is a flangelike proximal extension which
meets the distal border of the IBiv As a result of this, the axillaries are seen to have
straight lateral borders, meeting those of the neighboring axillaries, which are about
as long as the sides of the IBrt. The IIBr series are 2.

The 10-13 arms are 190 mm. long. The first brachials are half again as long
exteriorly as interiorly, four times as broad as the median length; the proximal and
distal edges are parallel from the inner border as far as the median line, where the distal
edge runs at an angle to the proximal edge to the outer distal angle. The inner distal
angle is somewhat produced and broadly rounded, slightly overlapping the adjacent
portion of the second brachial. The second brachials are about twice as large as the
first, almost twice as long exteriorly as interiorly. The proximal border is in the form
of an obtuse angle with the apex in the median line. The first syzygial pair (composed
of brachials 3 + 4) is oblong, three times as broad as long; the dorsal surface of both the
hypozygal and epizygal is swollen, so that the syzygial line lies in a groove between
them. The next 10 brachials are oblong or slightly wedge-shaped, about four times as
broad as the median length. The middle of the dorsal surface is raised into a high
ridge distal to which the surface slopes evenly to the distal border, while proximally it
drops almost or quite perpendicularly to the longitudinal axis of the arm, so that
proximally the ridge is bordered by a narrow portion of the surface of the brachial
which is parallel with the longitudinal axis of the arm. Beyond the tenth brachial the
portion of the surface distal to the ridge becomes hollowed so that the ridge becomes
narrower and more conspicuous. On the earlier triangular brachials the ridge is strongly
and regularly curved, passing from the distal end 'of the shorter side inward and down-
ward through the proximal third of the median line and upward and outward to near
the distal end of the longer side. Soon the ridge becomes angular, the apex of the angle
being in the middle of the median line. It then moves distally and soon comes to
coincide with the distal border of the brachials, where it disappears. On the triangular
brachials the midline proximal to the angle of the ridge is raised into a rounded keel.
As the ridge moves distally and disappears this median keel becomes narrower and more
prominent, though always very low and rounded, and persists to the arm tips.

212 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

On arms arising from a IIBr axillary and not quite of full size the first six brachials
are wholly without ornamentation, but the midline is rather narrowly rounded, or
faintly subcarinate. On the succeeding brachials the distal border is slightly thickened,
and the median carination becomes more distinct. On the earlier triangular brachials
the thickening of the distal edge disappears, leaving only the low median carination
which persists to the arm tips.

PI is 1 1 mm. long with 29 segments and tapers evenly from the base to the slender
and flagellate tip. The first segment is twice as broad as long with the distal border
strongly concave. The second segment is narrower, about as long as broad at the base,
with diverging sides so that its distal angles overlap the base of the succeeding segment.
The following segments are of decreasing size, with less and less overlapping of the
distal corners, those after the fifth being very small and somewhat broader than long.
P3 is 1 1.5 mm. long with 22 segments, similar to PI but less slender with larger segments,
all of which are broader than long. P3 is 14 mm. long with 21 segments, most of which
are about as long as broad; it is considerably stouter than P2. P4 is 14 mm. long with
17-18 segments of which the third to eighth are slightly broadened and the terminal
6 or 7 are about half again as long as broad. The following pinnules are similar. The
broadening is greatest on the fifth and sixth segments, later on the fourth and fifth,
from which point the pinnule tapers very gradually to the slender tip.

The specimen from the Danish Expedition to the Kei Islands station 59 is small with
21 arms 90 mm. long. One IIIBr 2 series is present, externally developed. The
borders of the elements of the IBr series bear a few widely scattered beadlike tubercles.

The specimen from the Sahul Bank is young.

Localities.— Albatross station 5356; North Balabac Strait, Philippines jBalabac Light
bearing S. 64° W., 15.5 miles distant (lat. 8°06'40" N., long. 1 17°18'45" E.) ; 104 meters;
sand and shells; January 5, 1908 [A. H. Clark, 1911; F. W. Clarke and W. C. Wheeler,
1914, 1917, 1922 (given by error as station 5036)] (3, U.S.N.M., 35704).

Challenger station 192;near the Kei Islands (lat.5°49'15"S.,long. 132°14'15"E.);
256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hamann, 1907;
A.H.Clark, 1907, 1909, 1912, 1913, 1916, 1918;Hartlaub, 1912;Gislen, 1927, 1928, 1934]
(2, B.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 3; 245 meters;
sand; March 31, 1922 (2, C.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 8; about 300
meters; mud; May 5, 1922 (3, U.S.N.M., E. 3190; C.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 46; 250 meters;
May 2, 1922 (1, C.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 59; 385 meters;
May 12, 1922 (1, C.M.).

Sahul Bank [Bell, 1894; A. H. Clark, 1911, 1912, 1913, 1916, 1918] (1, B.M.).

Geographical range. — From the Philippines southward to the Kei Islands and the
Sahul Bank.

Bathymetrical range. — From 104 to 385 meters; the average of six records is 257
meters.

History. — Antedon patula was described by Dr. P. H. Carpenter in his report
on the comatulids of the Challenger expedition published in 1888, his material consisting

A MONOGRAPH OF THE EXISTING CRINOIDS 213

of two specimens. In 1894 Prof. F. Jeffrey Bell recorded four specimens from the
Sahul Bank, figuring portions of the arms of three of them and the distal portion of
the cirri of two. He wrote that he was at first inclined to consider the four specimens
which he included under the name Antedon patula as representatives of a new species,
but Carpenter's species is founded on two specimens of much the same size, and smaller
and younger examples such as he had before him might well have a smaller number
of cirri and a less marked development of the ridge on the more distal of the brachials.
He noted that Antedon flexilis, A. patula, and A. robusta were all taken at the same
station by the Challenger and remarked it is very likely that an increase in our series
may show that there are not so many well-marked species as has been supposed.

In my first revision of the old genus Antedon published in 1907 patula was trans-
ferred to the new genus Charitometra, and in the same year it was listed as Antedon
patula by Hamann. Upon the establishment of the genus Pachylometra in 1909
I transferred it to that genus. In 1911 I recorded and gave notes on three specimens
of Pachylometra patula from Albatross station 5356, and in my memoir on the Recent
crinoids of Australia I included the record from the Sahul Bank. In my memoir
on the crinoids of the Indian Ocean published in 1912 I listed Pachylometra patula,
giving the synonymy and locality records, and in the same year Dr. Clemens Hartlaub
mentioned Antedon patula in his discussion of the Spinifera-group of the genus Antedon.
In 1913 I noted that at the British Museum I had examined two specimens of Pachy-
lometra patula from Challenger station 192, and one young specimen from the Sahul
Bank recorded as Antedon patula by Bell. A second specimen from the Sahul Bank
I identified as Pachylometra robusta.

In 1914 Prof. Frank Wigglesworth Clarke and Dr. W. C. Wheeler published
an analysis of the inorganic constituents of the skeleton of Pachylometra patula; they
gave the locality of their material as Albatross station 5036, which is an error for station
5356.

In 1916 I transferred patula to the new genus Perissometra, and in my memoir
on the unstalked crinoids of the Siboga Expedition published in 1918 patula was included
in the key to the species of Perissometra and the synonymy and range were given.

In his report on the crinoids collected by Dr. Th. Mortensen in Japan published
in 1927 Prof. Torsten Gislen discussed the genera Glyptometra and Perissometra,
pointing out the unsatisfactory nature of the supposed differences between them and
suggesting that patula should be transferred to Glyptometra. In 1928 he wrote that
the two specimens from Challenger station 192, wlu'ch he had examined in the British
Museum, represent two widely different forms, one of which ought to be referred to
Monachometra. In 1934 he classed the arm division of Perissometra patula with the
Asterometra type.

MONACHOMETRA FLEXII.IS fp. H. Carpenter)
[See vol. 1, pt. 2, pi. 44, figs. 1288-1290, 1292.]

Antedon flexilis VON GRAFF, Challenger Reports, Zoology, vol. 20, pt. 61, 1887, pp. 8, 12 (Challenger
station 192; myzostomes; nomen nudum). — P. H. CARPENTER, Challenger Reports, Zoology, vol. 26,
pt. 60, 1888, pp. 128, 217 (description; Challenger station 192), pi. 42. — HARTLAUB, Bull. Mus.
Comp. Zool., vol. 27, No. 4, 1895, p. 130 (systematic and bathymetrical relationships), p. 134 (size
compared with that of A. [Thalassometra] agassizii [erroneously given as 55 cm. instead of 35 cm.]),
p. 135 (compared with A. [Thalassometra] agassizii). — MINCKERT, Arch. Naturg., Jahrg. 71, 1905,

214 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

vol. 1, Heft 1, pp. 211 and following (syzygies; regeneration). — HAMANN, Bronn's Klassen und
Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, pp. 1578, 1581 (listed). — HARTLAUB, Mem.
Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 309 (in Spinifera group; history).

Charitometra flexilis A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed).

Pachylometra flexilis A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed); Proc.
U. S. Nat. Mus., vol. 39, 1911, p. 557 (correction of the dimensions given in the original descrip-
tion); Proc. Biol. Soc. Washington, vol. 25, 1912, p. 77 (comparison with P. crassa); Crinoids of
the Indian Ocean, 1912, pp. 33, 34 (identity), p. 219 (synonymy; locality); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 48 (published references to specimens in the B. M.; Challenger
station 192).

Perissometra flexilis A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. 178 (in key; range), p. 182 (references). —
GISL£N, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 37 (notes).

Diagnostic features.— The brachials in the proximal portion of the arms have
unmodified distal edges; the centrodorsal is columnar or slightly tapering with the
cirrus sockets arranged in 10 columns, the midradial lines bare; the 10-13 arms are
about 175 mm. long; and the cirri have 20-25 segments.

Description. — The centrodorsal is columnar or slightly tapering with its ventral
angles produced into marked interradial processes. The cirrus sockets are arranged in
10 columns which are in contact interradially but separated by a bare line in the
midradial areas; there are 3 or 4 sockets hi a column.

The cirri are XXX-XXXV, 20-25. The segments are stout but very smooth,
and are mostly longer than broad. In the figure they are shown as from very slightly
longer than broad to about one-third again as long as broad. The penultimate segment
bears an opposing spine.

The radials are visible. The radials and the elements of the IBr series, especially
the IBr2 (axillaries) are rather sharply convex with a more or less distinct median
tubercle. The IBr axillaries are subhexagona-1 and considerably broader than the
IBri which are short and bandlike and in close contact laterally. The IIBr series,
when present, are 2.

The 10-13 arms are about 175 mm. long. The first two brachials or the elements
of the IIBr series, when these are present, have median tubercles like those of the IBr
series, but less prominent. The IBr axillary and the two following segments have
sharp straight edges and flat wall-like sides. The inner side of the second and third
(hypozygal) brachials are also flattened, especially when the IIBr series are absent. The
lower brachials are somewhat discoidal with very rounded surfaces, and those following
are shortly triangular with the edges slightly raised, but they gradually become more
smooth and relatively longer.

Syzygies occur between brachials 3+4, again from between brachials 13+14 to
between brachials 19+20, and distally at intervals of from 4 to 8, usually 5 or 6, oblique
muscular articulations.

The first pinnules reach 13 mm. in length and are composed of about 40 short and
broad segments; their outer sides are somewhat flattened against one another below.
The pinnules following are of about the same length, but the segments gradually
increase in size and diminish in number, still remaining much broader than long. In
the pinnules of the sixteenth and of several of the following brachials the fourth and
fifth segments are considerably broader than their fellows, but in the later pinnules
the segments are longer than broad.

A MONOGRAPH OF THE EXISTING CRINOIDS 215

The disk is 10 mm. in diameter, not much plated except along the ambulacra.
There is a strong covering of plates over the gonads, with numerous sacculi imbedded
in it. The later pinnules have a well-defined ambulacral skeleton, the sacculi alternat-
ing with the side plates.

The color in alcohol is a light whitish brown with a brownish gray ventral perisome.

Notes. — Carpenter gave the expanse of the specimen he described as 55 cm., which
is equivalent to an arm length of 275 mm. But his figure shows a specimen with an
arm length of about 250 mm., at an enlargement of \% times, which, corrected, gives an
arm length of 176 mm. Apparently, therefore, the expanse as given, 55 cm., is a
typographical error for 35 cm.

I examined two fine specimens from Carpenter's type series at the British Museum
and found this to be a large, robust, and handsome species.

After examining the same specimens Prof. Torsten Gislen wrote that the centro-
dorsal is a high cone. The cirri are in 10 columns, and are without dorsal spines.
The opposing spine is forked or transverse. The genital pinnules have rather much
expanded segments.

Locality. — Challenger station 192; near the Kei Islands (lat. 5°49'15" S., long.
132°14'15" E.); 256 meters; blue mud; September 26, 1874 [von Graff, 1887; P. H.
Carpenter, 1888; Hartlaub, 1895, 1912; Minckert, 1905; A. H. Clark, 1907, 1909, 1911,
1912, 1913, 1916, 1918; Gisldn, 1928] (2, B. M.).

History. — Prof. Ludwig von Graff in the Challenger report on the myzostomes
published in 1887 mentioned Antedon flexilis as a host of certain species. The name,
which had been given him by Dr. P. H. Carpenter, was a nomen nudum.

In 1888 in his memoir on the comatulids of the Challenger Expedition Carpenter
described Antedon flexilis in detail and figured it. Dr. Clemens Hartlaub in 1895
discussed the systematic and bathymetrical relationships of A. flexilis and compared
it with his new species Antedon (Tlialassometra) agassizii. Minckert in 1905 discussed
the syzygies of Antedon flexilis, and Hamann listed it in 1907.

In my first revision of the genus Antedon published in 1907 flexilis was transferred
to the new genus Charitometra; it was again transferred to a new genus, Pachylometra,
in 1909. In the same year I published a correction of the dimensions given by Car-
penter in his original description, and in 1912 I compared it with a new species, Pachylo-
metra crassa.

Hartlaub in 1912 mentioned Antedon flexilis in connection with his discussion of
the Spinifera Group, and in my memoir on the crinoids of the Indian Ocean published
in the same year I listed Pachylometra flexilis, giving the synonymy and locality. In
1913 I published a brief note on two of Carpenter's specimens which I had examined in
the British Museum.

Upon the establishment of the new genus Perissometra in 1916 flexilis was trans-
ferred to it, and in my report on the unstalked crinoids of the Siboga Expedition pub-
lished in 1918 flexilis was included in the key to the species of Perissometra and the
synonymy and range were given.

Prof. Torsten Gislen in 1928 published a note on the two specimens he had examined
in the British Museum.

216 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

MONACHOMETRA ROBUSTA (P. H. Carpenter)

Antedon robusta P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 220 (descrip-
tion; Challenger station 192), pi. 44, fig. 1.— HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4,
1895, p. 134 (size compared with that of A. [Thalassometra] agassizii). — HAMANN, Bronn's
Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — A. H. CLARK,
Crinoids of the Indian Ocean, 1912, p. 34 (identity). — HARTLAUB, Mem. Mus. Comp. Zool.,
vol. 27, No. 4, 1912, p. 309 (in Spinifera group; history).

Antedon patula (part) BELL, Journ. Linn. Soc. (Zool.), vol. 24, 1893, p. 341 (Sahul Bank).

Charitometra robusta A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed).

Pachylometra robusta A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed), p. 82
(compared with P. macilenta); Crinoids of the Indian Ocean, 1912, p. 34 (identity), p. 220
(synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 49 (published references
to specimens in the B. M.; Challenger station 192; Sahul Bank).

Perissometra robusta A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, pp. 176, 178 (in key; range), p. 179 (references;
notes; Sta. 297), p. 275 (listed). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45,
No. 11, 1934, p. 20.

Monachometra robusta GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 9, No. 40 (notes).

Diagnostic features. — The brachials in the proximal portion of the arms are smooth,
without raised distal edges; the centrodorsal is low, thick discoidal, with the cirrus
sockets arranged in 15 closely crowded and somewhat irregular columns; the 12-17
arms are up to 250 mm. long; and the cirri are up to 70 mm. in length with up to 31
segments.

Description. — The centrodorsal is a thick disk 9 mm. in diameter.

The cirri are about L, 18-31 ; according to the figure all the segments except the basal
are usually longer than broad, although the last two or three may be about as long as
broad. The longest segments are from one-third to one-half again as long as broad.
There is a small opposing spine.

The radials are just visible in the angles of the calyx above the low interradial
processes of the centrodorsal, which partly conceals the short IB^ in their median line.
The IBr2 (axillaries) are widely rhombic with an obtuse distal and sharper proximal
angle, the latter rising to form a prominence (synarthrial tubercle) with the IBri. The
IIBr series are 2, one being present on each of two postradial series.

The 12 arms are nearly 250 mm. long and are composed of more than 200 brachials.
The first two brachials (or the elements of the IIBr series) bear a synarthrial tubercle
like the IBr series, and have much flattened outer sides like the axillaries. The inner
sides of the second brachials and both sides of the first syzygial pair are also sometimes
flattened. The first few brachials are oblong, the later more triangular.

Syzygies occur between brachials 3+4, the next not until after brachials 21 + 22;
the distal intersyzygial interval is long, from 10 to 26 oblique muscular articulations.

PI is about 12 mm. long and is composed of about 20 segments the lowest of
which are much larger than their successors and are of almost prismatic shape, being
flattened against the corresponding segments of the adjacent pinnules. Pa is similar
but slightly smaller, and its successors are of about the same length, but have broader
and flatter segments. The later pinnules gradually become elongated, but none of
the segments are conspicuously wider than the rest. In the styliform middle and
outer pinnules the first segment is flattened and expanded, with a curved distal edge.

The disk is 12 mm. in diameter, thickly plated, as are also the arms, both along

A MONOGRAPH OF THE EXISTING CRINOIDS 217

the ambulacral grooves and in the interarticular regions. The genital pinnules are
protected by irregular plates, and the ambulacra of the later pinnules have well-defined
side plates with alternating sacculi, which are also fairly abundant on the genital
pinnules.

In alcohol the perisome is dark blackish brown, the skeleton whiter.

Notes. — Prof. Torsten Gisl4n examined Carpenter's original specimen of this species
at the British Museum in 1925, and published the following notes upon it. The cenlro-
dorsal is discoidal, 11 mm. in diameter; it has a smaller radial and larger interradial
star dorsally, just as in certain Jurassic and Cretaceous comatulids. The cirrus sockets
are striated, with small lateral tubercles. The cirri are about XXXV, in 15-20 slightly
irregular columns. The arms are about 250 mm. long with a weak synarthrial carina-
tion. After examining the specimen in 1910 I wrote that this is a magnificent species
remarkable for its stoutness, and that it is well figured in the Challenger report.

The specimen from Menado Bay, Celebes, is small with 17 arms; seven IIBr 2
series are present.

In one of the specimens from Siboga station 297 the centrodorsal is large and
thick, truncated conical, 8 mm. broad at the base and 3.6 mm. across the stellate
dorsal pole, and 6 mm. high; on the proximal edge of the centrodorsal there are rounded
interradial ridges which are produced distally in a sharp angle between the proximal
portion of the proximal cirrus sockets, which meet below them; proximally these fork,
becoming prominent rather high tubercular processes on either side of the end of the
basal ray, which they much resemble; the surface of the stellate dorsal pole is slightly
concave hi the center, with more or less marked radial and interradial grooves ; the ends
of the rays of the star are not interradial but are somewhat twisted clockwise so that
they come under the left column of cirrus sockets in each radial area. The cirrus
sockets are arranged in 10 crowded columns of two each, with one in the center of a
radial depression and one on an interradial ridge.

The cirri are from 55 to 70 mm. long with 28-31 segments, of which the first four
are short, those following gradually increasing hi length to the ninth which, with the
following, is about half again as long as broad. The distal ventral edge of each seg-
ment projects slightly above the base of the succeeding segment. The last six or seven
segments taper very gradually so that the cirri, which throughout most of their length
are about 2 mm. broad, become on the penultimate segment 1.2 mm. broad. The
opposing spine is represented by a very slight terminal tubercle. The penultimate
and the distal third of the antepenultimate segment (sometimes the penultimate and
antepenultimate and the distal third of the segment preceding) are highly polished, in
contrast to the dull surface of the preceding ossicles.

The ends of the basal rays are visible as prominent dorsoventrally elongated
tubercles in the angles of the calyx.

The edge of the radials is just visible beyond the rim of the centrodorsal. The
IBrt are very short with parallel sides, distally incised by a rounded posterior projec-
tion from the axillary, laterally curving upward and meeting over the ends of the basal
rays. The distal inner angles are somewhat cut away. The median third of the dorsal
surface is swollen, forming a more or less evident.laterally elongated large low rounded
tubercle. The proximal edge is slightly produced, especially in the lateral thirds, and
the distal outer angles are slightly swollen. The IBr2 (axillaries) are rhombic, twice

843803—50 18

218 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

as broad as long. The dorsal surface, except in the lateral thirds, is slightly raised,
most prominently hi the median line just within the proximal border and on the median
part of the two distal faces, just within the distal borders. The lateral angles are more
or less irregular, with a greater or lesser tubercular modification. The lateral edges
are more or less cut away, forming, with a similar truncation of the distal angles of the
IBri, a prominent water pore.

There are 14 arms, all in process of regeneration. The IIBr series are all 2 re-
sembling the IBr series and with the same water pores, but with the outer edges more
irregularly tuberculous. The first two brachials are similar to the elements of the
division series, and have water pores ulteriorly and exteriorly between them. The
remaining brachials have a smooth and unmodified surface as figured by Carpenter,
but this is possibly due to the fact that as yet they are incompletely regenerated.

The other specimen is essentially similar. There are 16 arms, all the IIBr series
being 2. Ah1 the arms except three, which are broken, are regenerating. The tubercles
on the ossicles of the division series and on the first two brachials are not quite so
extensive, though slightly more marked. The proximal and distal borders of these
segments, except hi the median line, are slightly produced and slightly scalloped, this
feature increasing progressively to the margin. The lateral edges are similarly pro-
duced and slightly swollen, but nearly straight without tubercular modification. Very
narrow transversely elongate slits, scarcely noticeable, mark the position of the future
water pores.

I remarked that these specimens appear to represent Carpenter's robusla, though
they are more developed than his type. The chief characteristic of the species is the
very long and stout cirri.

Localities.— Menado Bay, northern Celebes (lat. 1°31' N., long. 124 °47' E.); 457
meters; Captain Christiansen, Great Northern Telegraph Company, March 12, 1913
(1, C. M.).

Challenger station 192; near the Kei Islands (lat. 5°49'15" S., long. 132°14'15"
E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hartlaub, 1895,
1912; Hamann, 1907; A. H. Clark, 1907, 1909, 1912, 1913, 1916; Gislen, 1928, 1934]
(1, B. M.).

Sahul Bank [Bell, 1893; A. H. Clark, 1913, 1918].

Siboga station 297; off Timor (lat. 10°39' S., long. 123°40' E.); 520 meters; soft
gray mud with a brown upper layer; January 27, 1900 [A. H. Clark, 1918] (2, U.S.N.M.,
E. 473; Amsterdam Mus.).

Geographical range. — From nothern Celebes southward to the Kei Islands, the
Sahul Bank, and Timor.

Bathymetrical range. — From 256 to 520 meters.

History. — In the Challenger report on the comatulids published in 1888 Dr. P. H.
Carpenter described and figured Antedon robusta on the basis of a single specimen from
station 192. Prof. F. Jeffrey Bell in 1893 inadvertently included a specimen of this
species in his record of Antedon patula from the Sahul Bank. Dr. Clemens Hartlaub
in 1895 compared the size of Antedon robu-sta with that of his new species A. (Thalas-
sometra) agassizii.

In 1907 I transferred Antedon robusta to my new genus Charitometra, and hi the
same year A. robusta was listed by Hamann. On the establishment of the new genus

A MONOGRAPH OF THE EXISTING CRINOIDS 219

Pachylometra in 1909 robusta was transferred to it, and laterjn the_same year I com-
pared Pachylometra robusta with the new species P. macilenta. In my jnemoir on the
crinoids of the Indian Ocean published in 1912 Pachylometra robusta\.*as listed and the
synonymy and original locality were given. In my notes on the crinoids of the British
Museum published in 1913 I recorded a specimen from the Sahul Bank that had been
included under Antedon pa-tufa by Prof. F. Jeffrey Bell in his'account of the crinoids of
that area. On the creation of the genus Perissornetra in 1916 I transferred robusta to it.
After an examination of Carpenter's type specimen in the British Museum Prof.
Torsten Gislen gave notes on it and remarked that this species, considered by me to be a
Perissmnetra, should be referred to Monachometra.

MONACHOMETRA FRAGILJS (A. H. Clark)

PLATE 20, FIGURES 62, 63
[See also vol. 1, pt. 2, figs. 824-830, p. 399.]

Pachylometra fragilis A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 79 (description;

Siboga station 166).
Monachomelra fragilis A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);

Unstalked crinoids of the Siboga-Exped., 1918, p. 185 (detailed description; station 166; also

Albatross station 5110), p. 273 (listed), pi. 24, figs. 68, 69.— [GISLEN, Vid. Medd. Dansk. Nat. Foren.

Kpbenhavn, vol. 83, 1927, p. 38 (comparisons) ; Kungl. Fysiogr. Sallsk. Handl., new ser., vol.

45, No. 11, 1934, pp. 18, 21.]
[Monachometra cf. fragilis GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, pp. 44, 51, fig. 14, p. 48 (base

of a post-radial series).]

Diagnostic features. — The brachials in the proximal portion of the arms have un-
modified distal edges; the centrodorsal is low, flattened hemispherical, with the cirrus
sockets arranged in 15 closely crowded and somewhat irregular columns; the 19 arms
are 145 mm. long; and the cirri have 17-20 segments. The synarthries are unusually
brittle.

Description. — The centrodorsal is low, flattened hemispherical, 7 mm. in diameter
at the base and 3 mm. high; in general the centrodorsal resembles that of the species of
Crinometra. The cirri are closely crowded and are arranged approximately in 2 or 3
irregular rows and 15 columns, 3 in each radial area; the sockets in the proximal row
reach the rim of the centrodorsal.

The cirri are about XXX, 17-18, from 30 to 35 mm. long and are moderately
slender. The first four segments are short, the fifth is half again as long as broad, the
sixth to eighth are twice as long as broad, and those following gradually decrease in
length so that the distal are about as long as broad, the terminal increasing again so
that the antepenultimate and penultimate are about twice as long as broad. The longer
proximal segments have slightly prominent ends, while the shorter distal have the dorsal
distal margin slightly swollen.

The ends of the basal rays are large and prominent, forming rhombic areas in the
angles of the calyx. Deep, though very narrow, subradial clefts arc present.

The radials are very short, strongly curved, with a low, broad, and obscure median
tubercle. The IBr( are exteriorly very short, bandlike, with an obscure low median
tubercle. The articular face is produced toward the center of the calyx so that their
sharply flattened lateral borders almost meet, being separated only by a narrowly

220 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

V-shaped cleft running to the edge of the inner end of the synarthrial joint face.
Though the dorsal surface of the ossicle is well rounded, the distance from the central
canal to the median part of the dorsal edge is not so great as the distance from the
central canal to the inner angle. Counting the entire median length of the joint face,
the broadest portion is found to be scarcely more than one-third the distance from the
dorsal edge to the inner angle. The ossicle is laterally sharply flattened from its widest
point inward. The IBr2 (axillaries) are low, rhombic, with the lateral angles truncated
so that the lateral angles are about as long as the lateral borders of the IBri. They are
twice as broad as long. There is an obscure well-rounded carination. The distal angle
is produced, but broad. The dorsal surface is rather strongly convex. The lower
portions of the axillaries are strongly produced inward so that, as in the case of the
IBri, the inner sides are reduced almost to apices which almost meet the similar inner
ends of the other axillaries. From this central point the inner face of the axillaries,
together with the division series, forms the platform upon which the visceral mass rests.
The sides of the inner half of the axillaries are sharply flattened. The IIBr series are 2,
similar to the IBr series but rapidly decreasing in dorsoventral width. They are sharply
flattened laterally for somewhat more than their inner half.

The 19 arms are 145 mm. long. The first two brachials are flattened laterally for
their entire inner side, and the first syzygial pair (brachials 3+4) is flattened on the
inner portion of the inner side.

P! is slender and evenly tapering, from 9 to 10 mm. long, composed of 26 to 31
segments, all of which are much broader than long. P% is similar but very slightly
stouter, of the same length or very slightly longer, with 25 segments, of which the outer-
most are about as long as broad. PS is 11 mm. long with 22 segments and in general
resembles Pa, but the segments in the distal half are about as long as broad. P^is 11
mm long with 20 segments which become as long as broad on the fifth or sixth and
slightly longer than broad terminally. P6 is 9 mm. long with 15 segments, most of
which are about as long as broad. P8 is 8 mm. long with 14 segments. P9 is 7 mm.
long with 13 segments. The distal pinnules are slender, 10 mm. long with 20 segments.
On the genital pinnules the third-seventh segments are very slightly, almost imper-
ceptibly, broadened.

The color in alcohol is brownish white, the centrodorsal and division series brownish
gray.

Notes.- — The specimen from Albatross station 5110 is smaller than the type speci-
men just described, though similar to it. It also has 19 arms. The fourth to tenth seg-
ments of the genital pinnules are somewhat expanded, more so than in the type speci-
men.

The specimen from the South China Sea is much broken. The longest cirri are
42 mm. long with 19-20 segments.

Localities.— Siboga station 166; Halmahera Sea (lat. 2°28'30" S., long. 131°03'18"
E.); 118 meters; hard coarse sand; August 22, 1899 [A. H. Clark, 1912, 1916, 1918;
Gislen, 1924, 1927, 1934] (1, Amsterdam Mus.).

Albatross station 5110; China Sea, off southern Luzon, Philippines; Corregidor Light
bearing N. 20° E., 25 miles distant (lat. 13°59'20" N., long. 120°25'45" E.) ; 247 meters;
bottom temperature 15.0° C.; dark gray mud; January 5, 1908 [A. H. Clark, 1918]
(1, U.S.N.M., 35707).

A MONOGRAPH OF THE EXISTING CRINOIDS 221

China Sea south of Pratas Reef (lat. 21°10' N., long. 117°30' E.); 704 meters;
bottom temperature 7.2° C. ; May 22, 1911; Captain Suensson (1, C.M.).

Geographical range. — From the Halmahera Sea to the northern part of the South
China Sea in the vicinity of Pratas Reef.

Bathymetrical range. — From 118 to 704 meters.

Thermal range—From 7.2° to 15.0° C.

History. — This species was first described under the name of Pachylometra fragilis
in 1912 from a specimen from Siboga station 166. In 1916 it was made the type of
the new genus Monachometra, and in 1918 in my memoir on the unstalked crinoids
of the Siboga Expedition Monachometra fragilis was described in detail and a second
specimen was recorded from Albatross station 5110.

In 1924 Prof. Torsten Gisl6n wrote that Monachometra cf. fragilis has the thir-
teenth brachial the first with the pinnule-bearing side longer than the other, and that
the distal angle of the IBr axillary measures 145°. He figured a postradial series of
his specimen showing a IBr series followed by a single arm ending with the fourteenth
brachial on the left and on the right a IIBr series with the left arm carried to the
fifteenth brachial. This postradial series represents not Monachometra fragilis, but
Parametra orion.

In 1927 Professor Gislen wrote I had informed him that the opposing spine of
Monachometra fragilis is double, hive that of Diodontometra bocki, and that there is a
specimen of M. fragilis in the Uppsala Museum which had permitted him to make
comparisons with a new species that he described as Monachometra mortenseni. He
gave no further information regarding the specimen at Uppsala, but his Monachometra
mortenseni is in reality Parametra orion. In 1934 Gislen distinguished two different
types of arm division which he called Monachometra fragilis types I and II. Both
are from the specimen in the Uppsala Museum, which appears to represent Parametra

orion.

Genus CHLOROMETRA A. H. Clark

Chlorometra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (diagnosis; genotype
Antedon garrettiana A. H. Clark, 1907); Crinoids of the Indian Ocean, 1912, p. 9 (absent from
Australia), p. 11 (absent from the west coast of the Malay Peninsula and from farther west),
p. 25 (range), p. 60 (in key), p. 225 (original reference; type) ; Die Crinolden der Antarktis, 1915,
p. 125 (certain species of this genus show the characters of Anlhomelra adriani); Unstalked
crinoids of the Szboga-Exped., 1918, p. 174 (in key; range), p. 190. — GISL&N, Kungl. Fysiogr.
Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20.

Diodontometra GISL£N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 121 (char-
acters; only included species D. bocki}; Zool. Bidrag Uppsala, vol. 9, 1924, p. 280; Vid. Medd.
Dansk Nat. Foren., K0benhavn, vol. 83, 1927, p. 38; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928,
p. 8; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 20, 21.

Diagnosis. — The genital pinnules have the third to fifth or third to sixth seg-
ments flattened and expanded with winglike borders, the portion of the pinnules
beyond being abruptly narrower and shorter than the expanded portion; the centro-
dorsal is sharply conical, higher than broad at the base, with the cirrus sockets in 5
midradial single or partially double columns; there are 14 to 20 arms about 60 mm.
long; and the opposing spine is forked.

Geographical range.— From southwestern Japan to the Bonin Islands.

Bathymetrical range. — From 165 to 210 meters.

222 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

History. — -The genus Chlorometra was established in 1909 with the genotype
Antedon garrettiana A. H. Clark, 1907, also including Carpenter's Antedon aculeata.
In 1916 Antedon aculeata was removed to the new genus Chondrometra. In 1922 Prof.
Torsten Gislen established the genus Diodontometra with the genotype D. bocki, which
proves to be a synonym of the very poorly and inadequately described Antedon
garrettiana.

CHLOROMETRA GARRETTIANA (A. H. Clark)

PLATE 20, FIGURE 64
[See also vol. 1, pt. 2, fig. 228, p. 184.]

Antedon garreUia.no. A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 142 (description; Albatross
station 4894).

Charitometra garrettiana A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed) ;
Proc. U. S. Nat. Mus., vol. 34, 1908, p. 318 (Japan).

Chloromelra garrettiana A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22 (listed);
Crinoids of the Indian Ocean, 1912, p. 225 (synonymy; locality); Journ. Washington Acad.
Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance); Un-
stalked crinoids of the Si&oja-Exped., 1918, p. 190 (references).

Diodontometra bocki GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 123
(description; Bock's station 56), figs. 79-83, p. 88, fig. 84, p. 112, pi. 2, fig. 10; Zool. Bidrag
Uppsala, vol. 9, 1924, pp. 41, 42, 44, 53, 80, figs. 81, p. 81 (syzygial face), 110, p. 93 (synarthrial
face), 177-179, p. 98 (pinnule articulations); Vid. Medd. Dansk Naturh. Foren., K0benhavn,
vol. 83, 1927, p. 2 (station 9; 162 meters), p. 38 (station 9; notes), p. 68 (listed), figs. 28-33,
p. 37; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 21.

Description. — The centrodorsal is conical, 3 mm. broad at the base and 2.8 mm.
high, with the dorsal pole papillose. The cirrus sockets are arranged in 10 closely
crowded columns, 2 in each radial area, the pairs of columns being separated inter-
radially by an irregular interradial ridge but crowded together radially so that here
the sockets alternate with each other.

The cirri are XX, 17; only a single cirrus remains, and this is not fully developed.
It is 20 mm. long. The first two segments are very short, more than twice as broad
as long, the third is twice as broad as long, the fourth is slightly broader than long,
and the fifth is about one-third again as long as broad; the next three are slightly
longer, the length then very slowly decreasing so that the antepenultimate is about
one-third again as long as broad. The penultimate is slightly longer. There is a
slight taper in the distal third of the cirri and the last two segments are dorsally
roundedly subcarinate. The opposing spine is terminal, small with a rounded and
not glassy tip, and is directed obliquely forward. The terminal claw is nearly as long
as the penultimate segment, moderately stout and evenly tapering, gently curved, and
glassy only at the tip.

The ends of the basal rays project strongly as large, rather narrow, more or less
rhombic tubercles in the interradial angles. They separate the proximal half of the
radials and extend downward between the sockets of the upper row, when the sockets
are small reaching down to those of the lower row.

The radials are rather narrow bands of uniform width with the center raised into
a prominent broad rounded tubercle. The IBri are short, nearly oblong, about four
times as broad as long, about twice as long as the radials, with the central portion
rather abruptly raised into a rounded keel. The IBr2 (axillaries) are about three times

A MONOGRAPH OF THE EXISTING CRINOIDS 223

as broad as long with the lateral borders about two-thirds as long as those of the IBr1(
in the midline about twice as long as the IBr^ the two distal sides are concave. A
rather abrupt broad rounded median keel resembling that on the IBrt runs their entire
length. The IIBr series are 2 and resemble the IBr series.

The 11 arms are 65 mm. long. The first two brachials are similar, slightly longer
exteriorly than interiorly, about four times as broad as long. They have raised rounded
median keels resembling those on the division series. The first syzygial pair (composed
of brachials 3 + 4) is about two and one-half times as broad as long and oblong; the
distal edge of the hypozygal is prominent so that the syzygial pah- has the appearance
of two short brachials. The next five brachials are slightly wedge-shaped, about three
times as broad as long. The tenth brachial is oblong. The brachials following the
tenth are very obliquely wedge-shaped, somewhat longer than broad, the proportions
remaining fairly uniform to the arm tips. Each brachial has a rather broad low raised
median line which in the distal portion of the arm gradually becomes obsolete. The
division series and first two brachials are in close lateral apposition and are sharply
flattened against each other, the flattened surface rapidly decreasing in width from
the IBr! on which it is about three times as broad as long to the second brachial on
which it is only as broad as the pinnule base.

Syzygies occur between brachials 3+4, again from between brachials 11 + 12 to
between brachials 15 + 16 (usually between brachials 14+15), and distally at intervals
of from 6 to 1 1 (usually 6 or 7) muscular articulations.

PI is 6 mm. long, rather slender, and tapering evenly and slowly to a rather delicate
tip. It is composed of 20 segments all of which are somewhat broader than long.
The first segment is about twice as broad as long, broadly crescentic with the outer end
rounded and the inner end truncated. The next two segments are roughly oblong,
and those following have the proximal border broadly and evenly rounded and the distal
border straight or slightly concave.

P2 is 5.5 mm. long with 17 segments. It tapers more slowly than PI and hence
appears somewhat stouter in the distal half, and the segments are more nearly oblong,
on the last ten becoming about as long as broad.

P3 is 5.5 mm. long with 13 segments resembling P2 but somewhat stouter.

The genital pinnules are from 3 to 4 mm. long with from 9 to 12 segments. The
first segment is crescentic, twice as broad as long, the second is trapezoidal, nearly as
long as broad, and those following are oblong, somewhat longer than broad. The two
terminal are small. In the shorter genital pinnules the third and fourth segments are
markedly longer and slightly broader than those following, though they are not broader
than the two basal segments; the third segment is about half again as long as broad or a
little longer, the fourth is twice as long as broad, and the fifth is slightly longer than broad.

The distal pinnules are 5 mm. long with 13 or 14 segments, of which all but the two
basal and the terminal are about one-tliird again as long as broad.

Notes. — There appears to be no doubt that Antedon garrettiana, very inadequately
described in 1907, was based upon an immature individual of the species described and
figured by Gislen in 1922 under the name of Diodontometra bocki, which in 1927 he
recorded from Mortensen's station 9, near the type locality of garrettiana.

The centrodorsal of the type specimen of garrettiana and the arrangement of thecirrus
sockets are very closely similar to the same features figured by Gislen in a specimen from

224 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Mortensen's station 9, although in garrettiana the centrodorsal is not quite so long, and
the interradial spaces are not quite so broad; the articular faces of the radials in bocki
are the same as those in garrettiana. The cirri have the same number of segments in
both, and the single cirrus that remains in the type specimen of garrettiana agrees with
the immature cirrus shown in Gislen's photograph extending up into the arms. The
form of the ossicles of the division series and of the brachials is the same hi both, as is
the carination, the production of the distal ends of the earlier brachials, and the smooth-
ness of the outer portions of the arms.

Features that might seem to indicate that bocki is not the same as garrettiana are:
In garrettiana the opposing spine is single, not forked; but the single cirrus present is of
the immature type, tapering in the distal portion, and the short blunt opposing spine
and terminal claw do not have the normal glassy texture; single opposing spines are not
infrequent in species in which the opposing spine is normally or usually forked. In
garrettiana, the ends of the basal rays are large and prominent tubercles whereas they
are not visible in bocki; that is simply an indication of immaturity, the basal rays being
commonly very large in immature individuals of the species of Charitometridae.
In garrettiana the radials are wholly visible as narrow bands, in bocki mainly concealed;
this also indicates immaturity. In the type specimen of garrettiana there are only 1 1
arms, and the single IIBr series and the arms borne by it are not of full size; this is
evidently the commencement of adolescent autotomy and indicates that fully mature
individuals have more than 10 arms; one of Gislen's specimens of bocki has 14 arms. In
garrettiana the arms are longer than in bocki — 65 mm. as contrasted with 60 mm. ; in
individuals with 10 arms the arms are always longer than in those of the same species
with 20 arms; the arm length of garrettiana is the distance from the apex of the cen-
trodorsal to the arm tip — that is, half the diameter of the circle made by the outstretched
arms; hi bocki the arm length is presumably the length of the arms from the last axillary;
measured on this basis the arm length of garrettiana would be the same as that of bocki,
60 mm. The proximal pinnules of garrettiana are longer than those of bocki with more
segments; in garrettiana Pt is 6 mm. long with 20 segments, in bocki 3.5-5 mm. long with
13-15 segments; in garrettiana P2 is 5.5 mm. long with 17 segments, in bocki 4.5-5 mm.
long with 12-14 segments; in garrettiana PS is 5.5 mm. long with 13 segments, hi bocki
4-4.7 mm. long with 10-11 segments; these differences are slight and do not affect the
relative proportions of the pinnules; they are probably due to the fact that the pinnules
of garrettiana were measured on an arm arising from a IBr axillary whereas those of
bocki were measured on an arm from a IIBr axillary. In the genital pinnules of
garrettiana the third and fourth segments are often abruptly larger than those following
and flattened; but they are not broader than those preceding and do not have produced
lateral borders as in bocki; this is probably an indication of immaturity; the expansion
of the genital pinnules is a very variable feature in most of the Charitometridae except
for the 10-armed species. In garrettiana the distal pinnules are 5 mm. long with 13—14
segments, in bocki 4 mm. long with 11 segments; this difference may well be due to
the fact that in garrettiana they were measured on an arm from a IBr axillary, in bocki
on an arm from a IIBr axillary.

In balancing these correspondences and differences it appears that the former are
fundamental, and taken together could scarcely be assumed to occur in two different
species, while the latter are all of minor significance and are explainable on the basis

A MONOGRAPH OF THE EXISTING CRINOIDS 225

of the immaturity of the type specimen of garrettiana hi contrast with the full maturity
of the described specimens of bocki.

Prof. Torsten Gisle"n described Diodontometra bocki as follows.

The centrodorsal is conical, pointed, 3.0 mm. hi diameter at the base and 3.5 mm.
high. The cirrus sockets are arranged hi five midradial groups separated by interra-
dial interspaces which are almost as broad as the areas occupied by the cirri. In
each midradial group there are 5 or 6 closely crowded sockets, often forming an almost
single row.

The cirri are XXVI, 15-17, from 15 to 20 mm. long, the smaller apical cirri with
10—12 segments and 5 or 6 mm. long. The first and second segments are short, the
third is about as broad as long, the fourth is longer, the fifth to seventh are two-thirds
again as long as broad, and the eighth or ninth and those following to the antepenulti-
mate are not much longer than broad. The dorsal surface of the segments is slightly
carinate and the distal dorsal ends are somewhat overlapping. There are no dorsal
spines. The opposing spine on the distal portion of the penultimate segment is large,
bifurcate, and often has a small lateral accessory spine. The terminal claw is longer
than the penultimate segment and is slender, curved, and pointed.

The radials are visible as narrow bands hi the interradial angles. The IBr] are
four times as broad as long and are in close lateral apposition hi the proximal half;
they are narrowed hi the midradial line by the posterior projection of the axillary.
The IBr2 (axillary) is pentagonal, twice as broad as long, like the IBri with a slight
median carination but otherwise rounded dorsally. The IIBr series are 2 and resemble
the IBr series. The ossicles immediately following the axillaries are hi close lateral
apposition in the proximal half.

The 19+ (probably originally 20) arms are 60 mm. long; hi four cases they are
broken off at the synarthrial articulation between the first two brachials. The first
two brachials have a slight synarthrial tubercle. The first 12 brachials are discoidal,
those following becoming wedge-shaped. The fifth to tenth brachials have the distal
ends a little overlapping, those following being smooth. The arms are laterally flat-
tened as far as the fourth brachial. Seven or 8 of the terminal brachials bear rudi-
mentary pinnules.

Of the two arms given as samples of the distribution of the syzygies by Gisl6n, one
has the first four brachials united hi two synarthrial pairs and the syzygies between
brachials 21+22, 31+32, and 41+42. The other also has the first four brachials
united hi two synarthrial pairs and syzygies between brachials 17 + 18, 26+27, 35+36,
and 44+45.

PI is 3.5 mm. long with 13 segmeats. P2 is 4.5 mm. long with 12 segments. P3
is 4 mm. long with 11 segments. P4 is 3.5 mm. long with 10 segments. The segments
on the first three pinnules are rather uniform, from twice as broad as long to as long
as broad; on the outer side of the third and following segments there are small wing-
like flanges partly caused by small notches between the segments. On P3 to P]2,
which are 3.5 to 4 mm. long with 10 or 11 segments, the third to fifth or sixth seg-
ments are flattened dorsoventrally, cup-shaped with winglike borders; the seventh to
eleventh segments are narrow and long again. In dorsal view the cup-shaped seg-
ments are about as long as broad, the distal over twice as long as broad. The distal
pinnules are 4 mm. long with 1 1 segments of which the first is short, the second is about

843803-

226 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

as long as broad, the third to tenth are half again as long as broad, and the terminal
segment is short. All the segments are smooth.

The disk has been thrown off. Sacculi are rather scarce.

The color is light brown.

Notes. — In one of the two specimens from Mortensen's station 9 as described by
Gislen the centrodorsal is conical, 3 mm, broad at the base and 3.5 mm. high. The
cirri are arranged as in the type specimen with from 3 to 6 in each radial group. The
cirri are XXII, 18, 16 mm. long, those near the dorsal pole with 12 segments and only
6 mm. long. The opposing spine is bifurcate.

The IBr! are five times as broad as long. The IBr2 (axillaries) have a median
carination hi the proximal three-fourths. The IIBr series are 2.

The 16 arms are all broken in the distal portion. From about the fifth to the
twenty-fifth brachials the distal borders are rather strongly everted and collar-shaped.
After about the twentieth brachial there is a weak median carination.

The intersyzygial interval is four or five muscular articulations.

P! is 4 to 5 mm. long with 15 segments. P2 is 4.8 to 5.5 mm. long with 14 seg-
ments. P3 is 4.7 mm. long with 10 segments. Ps is 4.5 mm, long with 10 segments.
The disk is 5 mm. in diameter and is covered with coarse calcareous granules. The
anal cone is inflated and wart-shaped, 1.5 mm. high.

The color is a very bright brown.

In the other specimen from Mortensen's station 9 the cirri are XXVIII, 16-18,
18 mm. long, the apical cirri with 12-14 segments and 9-12 mm. long. The dorsal
carination of the segments is well marked. In one case the opposing spine is doubled,
thus giving rise to four opposing spines on the penultimate segment. The centro-
dorsal is 3.5 mm. broad at the base and 4 mm. high. The radials are visible as flaps
in the interradial angles. The IBri are six times as broad as long. All the postradial
series are broken off at the synarthry in the IBr series.

Gisle'n wrote that this specimen had been sacrificed for more detailed study. The
cirrus sockets are, as evident from the figure, provided with short and broad incomplete
septa, from 10 to 15 in number. The lumen, which is transversely oval, is surrounded
by a low areola as in certain Cretaceous comatulids. There are broad interradial areas
on the centrodorsal free of cirri. New cirri are appearing on the ventral face of the
centrodorsal between this face and the radial ring. The centrodorsal cavity is nearly
as large as that of Leptometra. The basals are not visible externally. The free dorsal
part of the radials protrudes only in the interradial angles. The radial ring is 4 mm.
broad and 2 mm. high. The muscular fossae are high and narrow, excluding the inter-
articular fossae from the neighborhood of the lumen. The radial cavity is 0.8 mm. La
diameter, comparatively small, and is filled by a porous calcareous plug. This calca-
reous plug also fills the cavity of the ring that is formed by the five IBrj.

Localities. — Dr. Th. Mortensen's Pacific Expedition 1914-16, station 9; southern
Japan, off Kiu Shiu (lat. 32°15' N., long. 128°12' E.) ; 162 meters; hard bottom; May 15,
1914 [Gisl6n, 1927, 1934].

Albatross station 4894; Eastern Sea from 10 to 20 miles southwest of the Goto Is-
lands; Ose Saki Light bearing N. 41° E., 5 miles distant (lat. 32°33' N., long. 128°32'10"
E.); 174 meters; green sand, broken shells, and pebbles; August 9, 1906 [A. H. Clark,
1907, 1908, 1909, 1912, 1915, 1918] (1, U.S.N.M., 22633).

A MONOGRAPH OF THE EXISTING CRINOIDS 227

Dr. Sixten Bock's Expedition to Japan 1914; station 56; Bonin Islands, east of
the Channel; 210 meters; shells and sand; August 15, 1914 [Gislen, 1922, 1924, 1927,
1934].

Geographical range. — From southwestern Japan to the Bonin Islands.

Bathymetrical range. — From 165 to 210 meters.

History. — This species was described in 1907 under the name of Antedon garrettiana
from a single specimen from Albatross station 4894. Later in the same year it was
transferred to the new genus Charitometra. In 1908 Charitometra garrettiana was listed
as a Japanese species. In 1909 garrettiana was made the type of the new genus Chloro-
metra. In my memoir on the crinoids of the Indian Ocean published in 1912 Chloro-
metra garrettiana was listed and the synonymy and range were given. In 1915 it was
again listed as a Japanese species and the range and its significance were discussed.
In my memoir on the unstalked crinoids of the Siboga Expedition published in 1918
Chlorometra garrettiana was included, and I gave the synonymy and range.

Diodontometra bocki was described and figured by Prof. Torsten Gislen in 1922
from a single specimen collected by Dr. Sixten Bock in the Bonin Islands in 1914.
In 1924 Gisl6n described and figured the syzygies and the pinnule articulations. In
1927 he recorded and gave notes on two additional specimens that had been dredged
by Dr. Th. Mortensen off southwestern Japan, figuring certain details of the structure.
In 1934 he listed Diodontometra bocki as representing a special type of arm division.

Genus GLYPTOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Pop. Sci. Rev., vol. 4, No. 15, 1880, p. 194, and following authors.

Charitometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.

Glyptomelra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (diagnosis; genotype
Antedon tuberosa P. H. Carpenter, 1888), p. 83 (ornamentation compared with that of Pachy-
lometra invest igatoris) ; Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10 (represented in the West Indies
by Crinomelra) ; Crinoids of the Indian Ocean, 1912, p. 9 (absent from Australia), p. 10 (occurs
at the Hawaiian Islands [Pachylometra lateralis]), p. 11 (absent from the west coast of the Malay
Peninsula, the Andamans, and from farther west), p. 13 corresponds in part to the West Indian
Crinometra), p. 24 (range; for zoogeographical purposes may well be considered as one with
Pachylometra and Crinometra), p. 60 (in key), p. 224 (original reference; type); Internat. Rev.
gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4 and following (in part represents Crinometra of
the Atlantic; range); Die Crinoiden der Antarktis, 1915, p. 125 (certain species show the charac-
teristic features of Anthometra adriani), p. 181 (range; represents, in part, Crinometra of the
Atlantic) ; Unstalked crinoids of the Siboga-Exped., 1918, p. 173 (in key; range), p. 190. — GISLEN,
Vidensk. Medd. Dansk Nat. Foren., vol. 83, 1927, p. 35; Kungl. Fysiogr. Sallsk. Handl., new
ser., vol. 45, No. 11, 1934, p. 20.

Pachylometra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 20 (diagnosis; genotype
Antedon dislincta P. H. Carpenter, 1888); Vid. Medd. Nat. Foren. K0benhavn, 1909, p. 147
(the species of this genus agree in the variation of the IIBr series with the species of the West
Indian Crinomelra) ; Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10 (represented in the West Indies by
Crinometra), p. 13 (common to southeast Africa and the Bay of Bengal, but not occurring in the
Arabian Sea); Crinoids of the Indian Ocean, 1912, p. 11 (occurs both east and west of Ceylon),
p. 12 (represented in the Red Sea and in the southeast African regions), p. 13 (corresponds in part
to the West Indian Crinometra), p. 24 (range; for zoogeographic purposes may well be considered
as one with Glyptomelra and Crinometra), p. GO (in key), p. 215 (original reference; type). —
HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 286 (discussion). — A. H. CLARK,
Internat. Rev. Gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4 and following (in part represents
the Atlantic Crinomelra; range) ; Die Crinoiden der Antarktis, 1915, p. 125 (certain species show

228 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

the characters of Anthometra adriani), p. 164 (range), p. 181 (range; represents Crinometra). —
F. W. CLARKE and WHEELER, U. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 195 (inorganic constit-
uents of the skeleton) ; Prof. Pap. 102, 1917, pp. 23 and following (same). — A. H. CLARK, Unstalked
crinoids of the Siboga-Exped., 1918, p. 173 (in key; range), p. 184 (key to the included species). —
F. W. CLARKE and WHEELER, U. S. Geol. Surv. Prof. Pap. 124, 1922, p. 20 (inorganic constituents
of the skeleton). — GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922,
p. 120; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8; Vid. Medd. Dansk Nat. Foren. K0benhavn,
vol. 93, 1933, pp. 480, 481, 482; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934,
p. 22; Kungl. Svenska Vet.-Akad. Handl., ser. 3, vol. 17, No. 2, October 3, 1938, p. 5.

Crossometra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (diagnosis;
genotype Pachylomeira investigaloris A. H. Clark, 1909; range; included species); Unstalked
crinoids of the Siboga-Exped., 1918, p. 173 (in key; range), p. 174 (key to the included species. —
GISL£N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 119; Ark. Zool.,
vol. 19, No. 32, Feb. 20, 1928, p. 8 (notes); Vid. Medd. Dansk Nat. Foren. K0benhavn,
vol. 93, 1933, p. 482.

Perissometra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (diagnosis;
genotype Antedon flexilis P. H. Carpenter, 1888; range; included species); Unstalked crinoids of
the Siboga-Exped., 1918, p. 173 (in key; range), p. 176 (key to the included species). — GISLEN,
Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, pp. 10, 120; Vid. Medd. Dansk
Nat. Foren. K0benhavn, vol. 83, 1927, pp. 2, 35; Ark. Zool., vol. 19, No. 32, Feb. 1928, pp. 8, 9. —
A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 656. — GISLEN, Vid. Medd.
Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 481; Kungl. Fysiograf. Sallsk. Handl., new ser.,
vol. 45, No. 11, 1934, pp. 18, 20, 23.

Calyplomelra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (diagnosis;
genotype Charitometra lateralis A. H. Clark, 1908; range; included species); Unstalked crinoids
of the Siboga-Exped., 1918, p. 174 (in key; range), p. 189. — GISLEN, Kungl. Fysiogr. Sallsk.
Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20.

Glytometra PRESTON, Zool. Record for 1928, 1929, p. 32 Echin.

Diagnosis. — A genus of Charitometridae in which the genital pinnules taper evenly
from the usually more or less broadened earlier segments to a delicate tip, the portion
beyond the gonad being much longer than the gonad itself; the division series and arms
are rounded dorsally, with or without a fine median abruptly raised line and a tubercular
ornamentation on the division series and arm bases; and the oral pinnules are little or
not at all longer than the genital and distal pinnules.

(geographical range. — East Africa from Sokotra southward to East London, South
Africa, and eastward to Timor, the Sahul Bank, the Kermadec Islands, Fiji, and the
Hawaiian Islands, and northward to southern Japan.

Bathymetrical range. — From 55 to 2,194 meters.

Thermal range. — From4.17°to 15.00° C.; the average of all records is about 7.90° C.

Remarks. — As explained in the discussion of the family, there are no valid grounds
for maintaining the genera Pachylometra, Crossometra, Perissometra, and Calyptometra
as distinct from the earlier Glyptometra. Even with their inclusion the 15 species herein
recognized as constituting the genus Glyptometra form a very homogeneous unit the
specific lines within which are by no means always well marked — indeed it is quite
possible that some of the species now recognized are merely varieties or local forms of
others.

The species appear to be divisible into two groups hi one of which the cirri are stout
with short segments, whereas in the other they are more slender with longer segments.
Although this division seems to be valid as far as the formation of a key is concerned, it
should be pointed out that there is an almost continuous sequence from species in which

A MONOGRAPH OF THE EXISTING CRINOIDS 229

all the cirrus segments are much broader than long to species in which all but two or
three of the basal segments are much longer than broad. In both groups the number
of arms in the included species runs from 10 to 32 or 33, and in both groups the division
series and arm bases may be plain or may have a more or less developed usually rugose
ornamentation. In both groups the subdivisions are based upon the relative length of
the proximal and distal cirrus segments and the ornamentation. In the group with
slender and long-segmented cirri the arrangement of the cirrus sockets on the centro-
dorsal, whether in 10 or 15 columns, seems to be significant when fully matured indi-
viduals are compared, though species normally with 15 columns of cirrus sockets when
adult may have only 10 when young.

History. — The species of this genus known to Carpenter were assigned by him to
Antedon. All of them were transferred to Charitometra when I established that genus
in 1907. In 1909 I transferred some of the species of Charitometra to the new genera
Glyptometra and Pachylometra, and in 1916 I established the genera Crossometra and
Perissometra for species previously included in Pachylometra, and Calyptometra for one
of the species included in Glyptometra.

KEY TO THE SPECIES IN THE GENUS GLYPTOMETRA

a1. Cirri stout, the longest segments at most only slightly longer than broad.

b1. All the cirrus segments much broader than long, the longest from half again to twice as broad
as long; ossicles of the IBr series and first four brachials with the dorsal surface raised into a
broad blunt median tubercle, highest and most conspicuous on the division series; brachials
in the proximal fourth or third of the arm with indications of a broad low median tubercle;
10 arms 165 mm. long; cirri with 17-20 segments, 20-25 mm. long (Timor to northern Celebes;

457-520 meters) timorensis (p. 230)

b2. Longest cirrus segments about as long as broad or slightly longer than broad.

c1. Lower brachials with the distal ends thickened or everted, standing up more or less prom-
inently above the general surface of the ossicles; 10-20 arms 100-180 mm. long; IIBr series
usually 4 (3 + 4) (Celebes to the Kei Islands and Timor and west to the Nicobar Islands;

245-1,023 meters) crassa (p. 237)

c2. Lower brachials smooth, without projecting distal ends.

d1. Cirri of uniform width throughout, all the segments subequal, about as long as broad;
11-20 arms 100-145 mm. long (Philippines to Fiji and the Kermadec Islands; 1,152

meters) inaequalis (p. 343)

d1. Cirri broader distally than proximally, the longest segments about as long as broad, the
distal becoming slightly broader than long; 33 arms 130 mm. long (southern Japan; 366

meters) sep ten trionalis (p. 246)

a2. Cirri more slender, the longest segments, and often all the segments, markedly longer than broad.
61. Ossicles of the division series and all, or nearly all, the brachials with a low, narrow, sharp
median keel of uniform height; ossicles of the division series and earlier brachials with abruptly
everted borders and more or less numerous small beady tubercles or capitate spines scattered
over the dorsal surface; 10-18 (usually 10-12) arms 100-140 mm. long; IIBr series, when
present, 4(3 + 4) or 2 (northern Philippines to the Kei Islands; 245-929 meters).

tuberoaa (p. 232)
V. No narrow median raised line on the ossicles of the division series and arms, which are without

small beady or capitate tubercles.

c1. Cirrus sockets arranged in 10 columns on the centrodorsal.
d1. Cirri stouter, the distal segments not longer than broad.

el. Distal cirrus segments broader than long; 14-33 arms 100-205 mm. long (northern
Mindanao to the Kei Islands; 252-773 meters) distincta (p. 249)

230 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

e3. Distal cirrus segments about as long as broad.

/'. Division series and proximal brachials smooth; 18-32 arms 110-170 mm. long; cirri
with 20-31 segments; PD with 50-53 segments (northern Luzon southward to

Timor; 55-520 meters) investigatoris (p. 254)

f. Division series and arm bases rugose; 13-15 arms 130-170 mm. long; cirri with 15-22
segments; PI with 30 segments (Timorlaut to the Laccadive Islands and the Sey-
chelles; 914-1,462 meters) macUenta (p. 259)

<P. Cirri more slender with the distal segments all longer than broad; division series and arm

bases smooth, not rugose; 11-20 arms.

el. Proximal portion of the animal constricted, the sides of the IBr series being nearly
parallel, the IIBr series somewhat abruptly turned outward (Meangis Islands; 914

meters) ang-usticalyx (p. 263)

e*. Proximal portion of the animal not constricted.
/'. Division series and arm bases moderately broad; cirri with up to 21 segments (off

Sokotra; 2,194 meters) sparksi (p. 266)

f2. Division series and arm bases broader; cirri with 16 segments (vicinity of East London,

South Africa; 548-566 meters) sclateri (p. 268)

<?. Cirrus sockets arranged in 15 columns on the centrodorsal.

d1. Division series and arm bases smooth, without ornamentation; 12-14 arms 100 mm. long;

cirri with 14-15 segments (Philippines; 329-1,334 meters) levigata (p. 271)

<P. Division series and arm bases with rugose ornamentation.

«'. Outermost cirrus segments about as long as broad or broader than long; lateral edges of
the ossicles of the IBr series and earlier brachials not turned outward; 10 arms 115-

130 mm. long (southern Japan; 660 meters) lata (p. 272)

6s. Outermost cirrus segments, like those preceding, markedly longer than broad; lateral

edges of the elements of the division series and earlier brachials turned outward.
/'. Rugose ornamentation finer, the proximal brachials each with a small rounded central
tubercle; 12 arms 170 mm. long; cirri with 20-21 segments, 30-34 mm. long (off

South Andaman Island; 1,040 meters) invenusta (p. 275)

/2. Rugose ornamentation coarse, the proximal brachials each with a low broad hump;
cirri with 15-21 segments, 30-40 mm. long; 10-11 arms 160-180 mm. long (Hawaiian
Islands; 583-824 meters) lateralis (p. 276)

GLYPTOMETRA TIMORENSIS A. H. Clark

PLATE 21, FIGURES 66, 67
[See also vol. 1, pt. 1, fig. 100, p. 162.]

Glyptometra timorensis A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 80 (description;

Siboga station 297) .
Perissometra timorensis A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607

(listed); Unstalked crinoids of the Si&ojo-Exped., 1918, p. IX (relationship with P. lata), p. 177

(in key; range), p. 182 (detailed description; Sta. 297), p. 183, fig. 7, p. 275 (listed), pi. 24, fig. 71. —

GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8.

Diagnostic features. — All the cirrus segments are much broader than long; the
cirrus sockets are arranged in 10 columns on the centrodorsal; the 10 arms are up to
165 mm. in length; the ossicles of the division series and proximal brachials have the
lateral and the outer part of the proximal and distal edges everted and more or less
crenulate or scalloped; and the cirri are 20-25 mm. long with 17-20 segments.

Description. — The centrodorsal is very thick-discoidal, the sides sloping slightly
inward, 6.5 mm. in diameter at the base and 3.0 mm. high. The cirrus sockets are
arranged hi 10 columns of 2 each, the columns closely crowded against each other and
showing no separation into pairs.

A MONOGRAPH OF THE EXISTING CRINOIDS 231

The cirri are XX, 17-20, from 20 to 25 mm. long, and stout. The first segment
is very short, the following gradually increasing in length to about the seventh which,
with the following, is about twice as broad as the median length, or in the longest
cirri half again as broad as the median length. The dorsal profile of the segments
beyond the seventh or eighth is convex, becoming gradually more strongly so toward
the end of the cirri where the segments are very bluntly carinate.

The ends of the basal rays are visible as flat triangular or irregular areas in the
angles of the calyx.

The radials are entirely concealed, or slightly visible as small irregular tubercles
or flat irregular areas in the interradial angles. The IBri are short, broadly chevron-
shaped, the proximal and distal borders parallel, about four times as broad as long;
the proximal edge is produced into a thin border overlapping and concealing the proxi-
mal portion of the centrodorsal, though flush with its general surface; the border of
this produced edge is usually irregularly scalloped or bears a few low coarse teeth,
though it may be nearly plain; it may be evenly curved, becoming straight just over
the ends of the basal rays, or it may be regularly curved in its lateral third but nearly
straight in its median third; the middle of the dorsal surface of the IBrj is occupied
by a large and prominent oval well rounded tubercle. The IBr2 (axillaries) are
broadly rhombic with the lateral angles truncated so that the lateral edges are from
one-half to two-thirds the length of the sides of the IBr^ two and one-half tunes as
broad as long, hi the median line nearly twice as long as the IBri; the center, except at
the anterior angle, is occupied by a tubercle which is more elongated dorsoventrally
than that on the IB^ and, though as high, is less prominent as it rises much less
abruptly. The lateral edges of the elements of the IBr series are turned slightly out-
ward. The lateral thirds of the proximal edge of the axillaries and the corresponding
portions of the distal edge of the IBri are also turned upward to the same height as the
lateral edges; the eversion of the latter is most marked just over the ends of the basal
rays and gradually decreases anteriorly to the distal corner of the lateral edge of the
axillary, persisting, however, as far as the fifth brachial. The inner lateral edges of
the first five brachials are similarly modified.

The 10 arms are 165 mm. long. The first brachials are wedgeshaped, slightly longer
exteriorly than interiorly, twice as broad as the exterior length. The proximal border
is narrowly produced. The outer border is produced like the lateral borders of the IBr2.
The inner border is similarly produced, especially at the distal angle, which is more
or less rounded off and overlaps the proximal inner angles of the second brachials. The
second brachials are of about the size and shape of the first, with the outer edge similarly
produced; the production of the inner edge is like that of the outer, but it is not so
marked. The first syzygial pair (composed of brachials 3+4) is oblong, about twice as
broad as long, with the lateral edges turned outward as in the brachials preceding.
The following brachials are slightly wedge-shaped, about twice as broad as long.
One brachial between the ninth and thirteenth (usually the eleventh) is oblong, and
those following quickly become triangular, about as long as broad. The first four
brachials have a low and very broadly rounded -median carination, which is very
obscure; those following have an equally obscure slight and very broad convexity in the
middle of the dorsal surface which, after the eighth or ninth, becomes smaller in area
and resolves itself into a low rounded tubercle which gradually disappears after the

232 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

end of the proximal third, though it may be detected as far as the end of the proximal
half.

Localities.— Siboga station 297; Timor Sea (lat. 10°39' S., long. 123°40' E.); 520
meters; soft gray mud with brown upper layer; January 27, 1900 [A. H. Clark, 1912,
1916, 1918; Gislen, 1928] (4, U.S.N.M., E. 424, Amsterdam Mus.).

Menado Bay, northern Celebes (lat. 1°31' N., long. 124°47' E.) ; 457 meters; Captain
Christiansen, cable repair ship Nordiske, Great Northern Telegraph Company, March
12, 1913 (5, C. M.).

Geographical range. — From the Timor Sea northward to northern Celebes.

Bathymetrical range. — From 457 to 520 meters.

History. — Glyptometra timorensis was described in 1912 on the basis of four speci-
mens from Siboga station 297. It was referred to Perissometra on the establishment of
that genus in 1916. In my memoir on the unstalked crinoids of the Siboga Expedition
published in 1918 Perissometra timorensis was described in detail and figured. In 1928
Prof. Torsten Gislen wrote that timorensis, together with patula, lata,flexilis, and aranea
(=Parametra orion), should be included in the genus Perissometra, whereas all Perisso-
metras with the ILBr series 4(3 + 4) ought to be referred to Crossometra.

GLYPTOMETRA TUBEROSA (P. H. Carpenter)

PLATE 22, FIGURE 69
[See also vol. 1, pt. 2, fig. 816, p. 385, pi. 34, fig. 1211.]

Antedon tuberosa VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, p. 79 (Challenger
sta. 210; myzostomes ; nomen nudum). — P. H. CARPENTER, Challenger Reports, Zoology, vol. 26,
part 60, 1888, p. 126 (description ; Challenger station 210), pi. 14, fig. 9, pi. 23, fig. 2. — HARTLAUB,
Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrieal relation-
ships).— LANG, A text book of comparative anatomy, vol. 2, 1896, p. 375, fig. 326c. — HAM ANN,
Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed), pi. 11,
fig. 7 (pentacrinoid; from Carpenter). — A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 33
(identity) .

Charitomelra tuberosa A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed); Proc.
U. S. Nat. Mus., vol. 34, 1908, p. 228 (compared with Ch. [Calyptometra] lateralis) ; Geogr. Journ.,
vol. 32, No. 6, 1908, p. 603 (type of a non-oceanic group).

Glyptomelra tuberosa A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 19 (listed); Proc.
U. S. Nat. Mus., vol. 36, 1909, p. 407 (Albatross station 5236); vol. 39, 1911, p. 557 (Albatross
stations 5367, 5406, 5431, 5510, 5536, 5537; 6-rayed specimen described; specimen with undivided
post-radial series described); Crinoids of the Indian Ocean, 1912, p. 33 (identity), p. 224 (synonymy;
locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 49 (published reference to specimens
in the B. M.; Challenger station 210; characters of the ornamentation); Unstalked crinoids of the
iSi&oso-Exped., 1918, p. 190 (synonymy); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, pi. 2,
fig. 27 (side and covering plates). — GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 28, footnote;
Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 83, 1927, p. 33 (compared with Perissomelra
aranea), p. 35; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 9, No. 41 (notes).— A. H. CLARK,
Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 658 (between Cebu and Leyte; 154
fathoms). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22.

Diagnostic features. — A highly ornamented rather small and slender species; the
ossicles of the division series and earlier brachials have abruptly everted borders, a low,
narrow, sharp, and prominent median keel, and more or less numerous small beady
tubercles or capitate spines scattered over the dorsal surface; the 10-18 (usually 10-12)
arms are 100—140 mm. long; the IIBr series are 4(3 + 4) or 2; and the cirri, which are
arranged in 10 rows on the centrodorsal, have 11-15 rather long segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 233

Description. — The centrodorsal is a thick disk with a rough dorsal surface.

The cirri are XV-XX, 13-15. The fifth segment is the longest, and those following
gradually acquire a dorsal keel which passes into the small opposing spine of the penulti-
mate.

The radials are concealed. The IBri are short and broad, laterally united, and the
IBr2 (axillaries) are pentagonal, short and hroad, with a very obtuse distal angle. The
elements of the IBr series and first four brachials are straight edged and sharply flat-
tened laterally, and are more or less carinate in the median line. There are small blunt
tubercles on the dorsal surface of the IBr series and arm bases.

The 10 arms are 125 mm. long and consist of nearly 150 brachials. The first
brachials are oblong and closely united interiorly, the second more wedge-shaped; from
the third to the tenth the brachials are discoidal with the distal edge more or less raised
and crenulate, this feature disappearing on the brachials following, which are more
triangular and elongate considerably toward the arm tips. The lowest brachials,
especially on the younger arms, have a marked median keel which gradually dies away
in the middle third, the terminal brachials being quite smooth. Carpenter's figure shows
the elements of the IBr series and lower brachials with thickened and produced distal
ends, a conspicuous and narrowly rounded median keel fused with the produced distal
edge, somewhat everted lateral borders, and several small beadlike tubercles on the
dorsal surface. In the larger specimen, which I examined at London in 1910, I found
the ornamentation prominent and pearly; the median keels are not quite so prominent
as they are shown in the figure. In the smaller specimen the keels are proportionately
larger and more regular.

Syzygies occur between brachials 3+4, again from between brachials 11+12 to
between brachials 27 + 28, and distally at intervals of from 5 to 13, usually 7 to 9,
muscular articulations.

The pinnules of the first pair, PI and Pa are tolerably equal with 20-25 segments,
the lowest of which are broad and slightly keeled. The next pinnules slowly increase hi
length and size and have the third and following segments expanded to cover the gonads,
which are protected ventrally by strong plates; the fourth and fifth segments are larger
than the rest, though not markedly so. This feature ceases rather beyond the first
third of the arm and the pinnules then become more slender, with the basal segments as
long as, or longer than, broad.

The disk is 5 mm. hi diameter, much incised and paved with small plates. The
ventral surface of the arms is moderately plated, and the pinnule ambulacra have dis-
tinct side plates with intervening sacculi, which are also abundant in the plating over
the gonads.

In alcohol the arms are nearly white, the older ones a dark brownish gray.

The preceding description is adapted from the original description of Carpenter,
with a few additions by Gislen and by myself based upon an examination of Carpenter's
two specimens.

Notes. — The specimen from Albatross station 5367 has 18 arms; of the seven IIBr
series present six are 4(3 + 4) and one is 2, the last bearing externally a IIIBr 4(3 + 4)
series.

The specimen in the British Museum from between Cebu and Leyte has 10 arms.

234 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The specimen from Albatross station 5406 has 12 arms with both IIBr series 2.
It resembles the specimen from station 5367, but the dorsal carination of the division
series and arm bases is slightly more prominent.

There are 22 specimens from Albatross station 5410. Of these, 17 have 10 arms,
usually between 100 and 115 mm. long, those of the largest 140 mm. long. Three have
11 arms, the IIBr series being 2 in each case. One has 12 arms with both IIBr series 2.
The last has 6 rays and 12 arms.

Of the 2 specimens from Albatross station 5536 one has 10 arms 125 mm. long;
the other is of the same size with 12 arms, both the IIBr series being 2.

From Albatross station 5537 there are 2 nearly perfect specimens, both with arms
140 mm. long; both have regenerated disks. One has 12 arms, both IIBr series being 2.
The other has 11 arms; there are two IIBr 2 series, but one postradial series is not di-
vided, the IBr2 bearing a pinnule instead of being axillary, as in Eudiocrinus.

In a very young specimen from Albatross station 5236, tentatively referred to this
species, the lateral eversion of the elements of the IBr series and lower brachials is very
pronounced, and the characteristic median carination is indicated on the IBr series and
lower brachials; tubercles, however, have not as yet appeared. This individual is
remarkable for the very large size of the external ends of the basal rays.

The 2 specimens from Albatross station 5510 each have 10 arms 100 mm. long.

One of the specimens from the Danish expedition to the Kei Islands station 56 has
1 0 arms about 80 mm. long. There are 11-13 cirrus segments. The edges of the radials
and IBrj and the proximal edge of the axillaries are very strongly serrate, and the distal
edges of the axillaries are strongly everted. The axillaries have a sharp median keel
on either side of which is a single large tubercle. The first two brachials have a row of
three large and sometimes also two or three small tubercles, the middle one largest,
forming a blunt median keel. The first syzygial pah- has a strongly and broadly everted
distal edge which is sometimes lobate, and below this a transverse row of 5 or 6 tubercles
of various sizes, the middle one always the largest. The following wedge-shaped
brachials have the distal edge strongly and broadly produced — so broadly that almost
the entire dorsal surface is involved. Below the produced distal edge there is a series of
swellings, or more or less distinct tubercles; or the production may occupy the entire
dorsal surface of the brachial. The triangular and following brachials have the distal
border somewhat produced and usually more or less bluntly serrate ; they bear a low and
rounded median keel.

The pinnule segments are more or less produced at the edges, so that the borders
of the pinnules are strongly serrate.

Another specimen from the same station has 10 arms 75 mm. long, and the cirri
with 12-14 segments. The dorsal pole of the centrodorsal is irregularly tubercular.
The elements of the IBr series are irregularly tubercular, the axillaries with strongly
everted and irregularly crenulate edges and a high median keel. The first two brachials
have an elongate median tubercle, everted and crenulate edges, and a rugose dorsal
surface. The following brachials have a strongly everted distal edge and a rounded
median tubercle fused with, or incorporated in, this everted distal border; as the bra-
chials become obliquely wedge-shaped this transforms into a narrow and inconspicuous
median keel that persists to the arm tips.

A MONOGRAPH OF THE EXISTING CRINOIDS 235

Of the remaining three specimens from this station one lias 10 arms 75 mm. long
and the cirri with 12-13 segments, and another is similar with 10 arms 70 mm. long.

Pentacrinoid. — A pentacrinoid larva presumably of this species was described by
Carpenter (see Part 2, p. 523, pi. 34, fig. 1211).

Localities. — Albatross station 5367; Verde Island Passage; Malabrigo Light bear-
ing N. 81° E., 8 miles distant (lat. 13°34'37" N., long. 121°07'30" E.); 329 meters;
sand; February 22, 1909 [A. H. Clark, 1911] (1, U.S.N.M., 35668).

Between Cebu and Leyte, Philippines (lat. 11°07' N., long. 124°06' E.); 282
meters [A. H. Clark, 1929] (1, B. M.).

Albatross station 5406; in the vicinity of Dupon Bay, Leyte; Ponson Island (N.)
bearing S. 88° E., 10.2 miles distant (lat. 10°49'03" N., long. 124°24'23" E.); 479
meters; hard bottom; March 17, 1909 [A. H. Clark, 1911] (1, U.S.N.M., 35667).

Albatross station 5410; between Cebu and Leyte; Bagacay Point Light bearing
S. 37° W., 7.2 miles distant (lat. 10°28'45" N., long. 124°05'30" E.); 704 meters;
green mud; March 18, 1909 [A. H. Clark, 1911, as station 5431] (19, U.S.N.M., 35666).

Albatross station 5423; Jol6 (Sulu) Sea; Cagayan Island (S.) bearing S. 11° E.,
4.8 miles distant (lat. 9°37'05" N., long. 121°12'37" E.); 929 meters; bottom tem-
perature 9.88° C.; gray mud and coral sand; March 31, 1909 (2, U.S.N.M., 35988).

Challenger station 210; off the Panglao and Siquijor Islands (lat. 9°26' N., long.
123°45' E.); 685 meters; bottom temperature 12.28° C.; blue mud; January 25, 1875
[von Graff, 1884; P. H. Carpenter, 1888; Hartlaub, 1895; Lang, 1896; A. H. Clark,
1907, 1908, 1909, 1912, 1913, 1918; Gislen, 1924, 1927, 1928, 1934] (2 + , B.M.).

Albatross station 5529; between Siquijor and Bohol; Balicasag Island (C.) bearing
N. 11° E., 6.9 miles distant (lat. 9°23'45" N., long. 123°38'30" E.); 806 meters; bottom
temperature 11.66° C.; gray mud and globigerinae ; August 11, 1909 (1, U.S.N.M.,
36095).

Albatross station 5536; between Negros and Siquijor; Apo Island (C.) bearing
S. 26° W., 11.8 miles distant (lat. 9°15'45" N., long. 123°22'00" E.); 510 meters;
bottom temperature 11.94° C.; green mud; August 19, 1909 [A. H. Clark, 1911] (2,
U.S.N.M., 35665).

Albatross station 5537; between Negros and Siquijor; Apo Island (C.) bearing
S. 46° W., 8.7 miles distant (lat. 9°11'00" N., long. 123°23'00" E.) ; 464 meters ; bottom
temperature 11.94° C.; green mud; August 19, 1909 [A. H. Clark, 1911] (2, U.S.N.M.,
35664).

Albatross station 5236; off the east coast of Mindanao, Philippines; Magabao
Island (S.) bearing N. 85° W., 9 miles distant (lat. 8°50'45" N., long. 126°26'52"
E.); 903 meters; bottom temperature 5.17° C.; fine gray sand; May 11, 1908 [A. H.
Clark, 1909] (1, U.S.N.M., 35662).

Albatross station 5510; in the vicinity of northern Mindanao; Camp Overton
Light bearing S. 68° E., 9.1 miles distant (lat. 8°16'00" N., long. 124°03'50" E.);
773 meters; bottom temperature 11.66° C.; gray mud and fine sand; August 7, 1909
[A. H. Clark, 1911] (1, U.S.N.M., 35663).

Danish Expedition to the Kei Islands; Dr. Th: Mortensen; station 56; 245 meters;
May 10, 1922 (5, U.S.N.M., E. 3197; C. M.).

Erroneous locality. — Albatross station 5431 [A. H. Clark, 1911]. This is a typo-
grapliical error for station 5410.

236 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Geographical range. — From the northern Philippines to the Kei Islands.

Bathy metrical range. — From 245 to 929 meters.

Thermal range.— From 5.17° to 13.0° C.

History. — This species was first mentioned by Prof. Ludwig von Graff as Antedon
tuberosa (nomen nudum) in 1884 in his account of the myzostomes of the Challenger
expedition; he gave the locality as station 210. It was formally described and figured
as Antedon tuberosa from one entire specimen and a second much broken from Challenger
station 210 by Dr. P. H. Carpenter in his report on the comatulids of the Challenger
expedition published in 1888. At the same time Dr. Carpenter described and figured
a young pentacrinoid from the same station which he said must belong either to Antedon
tuberosa or to A. distincta, the only two species dredged at this station. He said that
from the appearance of the pentacrinoid he thought it should be referred to A. tuberosa.
In 1895 Dr. Clemens Hartlaub discussed the systematic and bathymetrical relation-
ships of Antedon tuberosa. In 1896 Carpenter's figure was reproduced by Lang, and
in 1907 his figure of the pentacrinoid was reproduced by Dr. Otto Hamann.

In my first revision of the genus Antedon published in 1907 tuberosa was assigned
to the new genus Charitometra, and in 1908 Charitometra tuberosa was compared with
the new species Ch. lateralis.

In my revision of the family Thalassometridae published on January 9, 1909,
Antedon tuberosa was made the type of a new genus, Glyptometra, and in a paper pub-
lished on May 13, 1909, I recorded and gave notes on a young specimen from Albatross
station 5236.

In a paper published in 1911 I recorded and gave notes on a number of specimens
of Glyptometra tuberosa from Albatross stations 5367, 5406, 5431 (=5410), 5510, 5536,
and 5537, mentioning a 6-rayed specimen and another with an undivided postradial
series.

In my memoir on the crinoids of the Indian Ocean published in 1912 Olyptometra
tuberosa was listed and the synonymy and range were given, the latter as Philippine
Islands in 51-423 fathoms. The depth 51 fathoms is that of Albatross station 5431,
an erroneous locality. In a paper on the crinoids of the British Museum published in
1913 I gave notes on Carpenter's two original specimens which I had examined in
London in 1910.

In my memoir on the unstalked crinoids of the Siboga expedition published in
1918 Glyptometra tuberosa was listed and the synonymy given. In the key to the genera
of the family Charitometridae the bathymetrical range of the genus Glyptometra was
given as 92-761 meters, the first figure, as in 1912, referring to Albatross station 5431.

In 1924 Prof. Torsten Gislen mentioned the pentacrinoid of Olyptometra tuberosa
described by Carpenter in 1888, in 1927 he compared this species with Perissometra
aranea, and in 1928 he published a note on the specimens in the British Museum.

In 1929 I recorded a specimen from between Leyte and Cebu in 154 fathoms,
and in 1934 Dr. Gislen discussed the arm branching of the species.

A MONOGRAPH OF THE EXISTING CRINOIDS 237

GLYPTOMETRA CRASS A (A. H. Clark)

PLATE 21, FIGURE 68

Pachylometra crassa A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 77 (description;
Siboga station 259).

Perissomelra crassa A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. 177 (in key; range), p. 181 (detailed descrip-
tion; station 259), p. 275 (listed), pi. 24, fig. 66. — GISLEN, Vid. Medd. Dansk Naturh. Foren.
K0benhavn, vol. 83, 1927, p. 35.— A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249,
April 1929, p. 658 (compared with P. occidentalis) . — GISLEN, Kungl. Fysiogr. Sallsk. Handl.,
new ser., vol. 45, No. 11, 1934, p. 22.

Perissometra gorgonia A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed;
nomen nudum); Unstalked crinoids of the St'6offa-Exped., 1918, p. 177 (in key; range), p. 179
(detailed description; stations 254, 294), pp. 274, 275 (listed); Journ. Linn. Soc. (Zool.), vol. 36,
No. 249, April 1929, p. 658 (south of the Nicobar Islands; 560 fathoms; notes). — GISLEN, Kungl.
Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22.

Diagnostic features.- — The longest earlier cirrus segments are nearly as long as
broad, the distal being somewhat shorter and usually with a small well-rounded sub-
terminal dorsal tubercle; the lower brachials have the distal edges prominently everted
or thickened, usually forming conspicuous half rings across the dorsal surface of the
arms; the 10-20 arms are 100-180 mm. long; and the cirri are 25-32 mm. long with
usually about 20 segments.

Description of the type specimen. — The centrodorsal is very large, 5 mm. across the
irregularly convex dorsal pole and 5 mm. high; it is truncated conical, the sides making
a rather small angle with each other. The cirrus sockets are arranged in 10 columns,
usually 3 to a column; the columns are closely crowded interradially and slightly
separated in the midradial line

The cirri are about XXV, 18-22 (usually 20), from 25 to 32 mm. long, stout and
short-segmented. The first segment is short, those following gradually increasing in
length so that the sixth and following are nearly as long as broad, those in the distal
third of the cirri being slightly shorter again. On the seventh a slight broad subterminal
dorsal hump makes its appearance which slowly increases in height so that the terminal
nine possess a prominent broad, blunt, and well-rounded subterminal tubercle which
becomes more pointed on the last two or three before the penultimate. The opposing
spine is small, subterminal, resembling the tubercle on the preceding segment, but
arising from a much smaller base.

The ends of the basal rays are concealed.

The radials are concealed. The IBri are very short, broadly V-shaped, sometimes
concealed in the median line so that only the lateral portions are visible ; the dorsal sur-
face is more or less irregular. The IBr2 (axillaries) are short and broad, nearly three
times as broad as long, rhombic with the lateral angles truncated so that the lateral
edges are nearly or quite as long as those of the IBr,. The IIBr series are 4(3+4).

The 10-11 arms are about 180 mm. long. The first two brachials are about equal
in size, slightly wedge-shaped (more pronouncedly so on the second), about three times
as broad as the median length. The broad and smooth synarthrial tubercles are
scarcely marked. The brachials have slightly produced distal edges and a more or less
swollen dorsal surface.

238 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Notes. — The specimens from Menado Bay, Celebes, and those from the Danish
Expedition to the Kei Islands stations 3, 8, 12, 58, and 59, were regarded as representing
a new species which was called annae. Although this name was never published the
specimens in the Copenhagen Museum, some of which may have been distributed to
other museums, all bear it so that it is well to mention it in order that their true identity
may be known.

All four of the specimens from Menado Bay have 10 arms. In one the dorsal
pole of the centrodorsal is thickly and conspicuously vermiculated with short meander-
ing rounded ridges of various lengths but of uniform height. The ends of the basal
rays are strongly and irregularly tubercular. The IBrt are very short, with the entire
surface irregularly tubercular. The IBr2 (axillaries) have a high rounded median keel,
the dorsal surface in the distal half is strongly and coarsely tubercular, and the proximal
border is finely and irregularly dentate. The first brachials have the surface coarsely
tubercular, the lateral edges rather broadly and strongly everted, and the proximal
border narrowly everted. The surface of the second brachials is much less irregular.
One of the other three is similar to this, but the other two have less strongly developed
ornamentation.

The seven specimens from the Danish Expedition to the Kei Islands station 3 all
have 10 arms which in one reach a length of 105 mm.

The three specimens from the Danish Expedition to the Kei Islands station 8 all
have 10 arms which are 115, 75, and about 30 mm. long.

The type specimen of annae from the Danish Expedition to the Kei Islands station
12 in the Zoological Museum at Copenhagen may be thus described.

The centrodorsal is discoidal, rather thick, with moderately converging sides and
a broad flat obscurely papillose dorsal pole 2 mm. in diameter. The cirrus sockets are
arranged in 10 columns of 2, or more rarely 3, each.

The cirri are XX, 15-17 (usually 16) , 20 mm. long. The first segment is very short,
the second is about four times as broad as long, the fourth is about as long as broad,
and those following are in the longest cirri slightly longer than broad and in the short
cirri about as long as broad. The three or four segments preceding the penultimate
have the distal border dorsally slightly swollen.

The ends of the basal rays are visible as rather prominent tubercules in the inter-
radial angles of the calyx.

The radials are entirely concealed. The IB^ are partially concealed, appearing
as a more or less narrow strip beyond the rim of the centrodorsal; then1 distal border is
thickened and everted, and scalloped or coarsely and prominently tubercular. The
IBr2 (axillaries) are regularly rhombic, from two and one-half to three times as broad
as long, with a high and conspicuous well-rounded ridge occupying the entire median
line and the edges irregularly thickened or with occasional irregularly placed tubercles.
The IBr series are broad, only slightly convex dorsally, in close lateral apposition, and,
hi common with the first two brachials, sharply flattened laterally.

The 10 arms are 100 mm. long. The first brachials are very short, roughly half
again as long exteriorly as ulteriorly, with the central portion more or less abruptly
swollen and the lateral edges more or less extensively thickened. The ulterior borders
of adjacent first brachials are in close apposition. The second brachials are more than
twice as large as the first. From the outer side the proximal and distal borders run

A MONOGRAPH OF THE EXISTING CRINOIDS 239

parallel to about the midline, then converge and meet in a more or less sharp point over
the inner ends of the first brachials. The surface is scarcely modified. The first
syzygial pair (composed of brachials 3+4) is somewhat longer interiorly than exteriorly,
and is usually about three times as broad as the median length. The surface of both the
hypozygal and epizygal is somewhat swollen, and each has a more or less conspicuous
large median tubercle. The next eight brachials are slightly wedge-shaped, four or
five times as broad as the median length. The distal half is rather abruptly thickened,
standing up as a thick transverse band across the arm. The segments following soon
become almost triangular, slightly broader than long, with the distal portion unmodified,
except that the distal edge is very finely spinous. On the short brachials following
the first syzygial pair the median portion shows a more or less marked broad rounded
tubercle ; on the longer brachials following this becomes a fairly conspicuous low narrow
rounded median carination which is traceable to the arm tips.

PI is 6-7 mm. long with 17-20 segments, slender and flexible, tapering gradually
and regularly from the base to the tip. The first segment is about two and one-half
times as broad as long, and those following very slowly increase in length, the terminal
being about as long as broad. The proximal border of the segments is in the form of an
obtuse angle the apex of which is truncated by the straight distal border of the segment
preceding. On the first seven or eight segments the two free sides are straight and
parallel with the axis of the pinnule; beyond this the sides curve inward from the
distal angles.

P2 is of the same length as PI or very slightly longer or shorter, and is composed of
15-17 segments. It resembles Pj but is slightly less broad basally and also tapers more
gradually so that it appears stouter in the distal half.

PS is usually 6 mm. long with 14 segments, resembling P2 but stouter; it may, how-
ever, be slightly longer than the pinnules preceding, 7 mm. long with 15 segments of
which the fifth is somewhat and the sixth is considerably enlarged, the next two seg-
ments decreasing hi width rather rapidly so that those beyond are slender and twice
as long as broad. On some pinnules the fifth to eighth segments are all almost equally
enlarged.

P4 is 7 mm. long with 15 segments of which the fourth and fifth are considerably
enlarged, and those following slowly decrease in size. The gonads are completely
protected ventrally by numerous stout plates of various sizes.

The pinnules following resemble P4. The distal pinnules are 7 mm. long with 18-19
segments which have slightly everted and very finely spinous distal ends.

The disk is almost completely covered with papilliform granules.

Another specimen from the Danish Expedition to the Kei Islands station 12 has
14 arms 120 mm. long; two of the post-radial series bear two IIBr series; in each case
that to the left is 4(3+4) and that to the right is 4. A third specimen has 12 arms
70 mm. long, two IIBr 2 series being present. A fourth has 11 arms 70 mm. long.
The fifth has 10 arms 90 mm. long.

The specimens from the Danish Expedition to the Kei Islands station 56 were
originally regarded as representing a new species which was called Glyptometra hector.
The type specimen may be described as follows:

The centrodorsal is truncated conical, about twice as broad at the base as high,
with a rather small, smooth, and slightly convex dorsal pole. The cirrus sockets are

240 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

arranged in 10 columns of 3 or 4 each. These columns are closely crowded against each
other interradially but in the midradial line they are separated by a V-shaped area, more
or less irregular, which at the rim of the centrodorsal varies from as broad as the
adjacent cirrus sockets to only half that width.

The cirri are about XXXV, 18-19, very stout, about 30 mm. long. The first
segment is extremely short, and the second is usually about twice as broad as long,
though it may be broader, or when the cirri are closely crowded it may be as long as
broad. The segments following increase in length so that the sixth is about as long as
broad. The next two are slightly longer than broad, and those succeeding are shorter
again, in the distal third of the cirri being from one-third to one-half again as broad
as long. The antepenultimate segment is slightly less in width than the segments
preceding, and varies from about one-third again as long as broad to as long as broad.
The last six to eight segments before the antepenultimate have the distal end dorsally
extending somewhat beyond the base of the succeeding segment, which in lateral view
is usually more or less rounded off, and the dorsal midlino of these segments is obscurely
carinate. The opposing spine is small, conical, terminal, and directed obliquely forward.
The terminal claw is about as long as the penultimate segment, rather stout, and moder-
ately and evenly curved.

The ends of the basal rays are visible as large irregular tubercles in the interradial
angles.

The radials are visible as usually large triangles, broader than high, that extend
downward between the topmost cirrus sockets in the free midradial triangles on the
centrodorsal; touching the basal angles of these radial triangles there are long usually
more or less lenticular tubercles extending diagonally forward between the ends of
the basal rays and the lateral borders of the IBri ; rarely these are reduced to more or
less circular conspicuous capitate tubercles. The IBri are very short, with the lateral
borders very strongly diagonal or divergent, as a result of the presence of the long
tubercles representing the anterolateral portion of the radials, and with the distal
border more or less strongly concave. The median third of the dorsal surface is raised
into a broadly rounded prominence. The IBr2 (axillaries) are twice as broad as long,
or even broader, triangular or more or less rhombic, with most or all of the median
portion raised and broadly rounded, corresponding to the raised center of the IBri.
The IIBr series are 4(3+4), all 10 being present and similar. They are very closely
appressed laterally and are sharply flattened against each other. The profiles of the
division series and arm bases on opposite sides make an angle of 45° with each other.
The lateral borders of the elements of the IIBr series are abruptly everted, especially
interradially. This eversion is greatest on the IIBri, less on the IIBr2, and is scarcely
noticeable on the two outer segments. A prominent rounded carination occupies the
midline of the IIBrj and IIBr2, and is represented in much reduced form on the syzygial
pair.

The 20 arms are 160 mm. long. The earlier brachials have broad, low, and incon-
spicuous median tubercles which are continued distally as a barely traceable carination
that is absent from some arms.

A small specimen from the same station has 10 arms 90 mm. long. The cirri are
15 mm. long with 13-14 segments. The ends of the basal rays are very large, and the
radials, which are nearly half as long as the IBri, are more or less crescentic, their lateral

A MONOGRAPH OF THE EXISTING CRINOIDS

241

borders turning anteriorly along the sides of the ends of the basal rays. The elements
of the IBr series have a high well rounded median carination, and the lateral borders
are somewhat everted. There is a faint indication of a broad low carination on the
arms.

One of the specimens from the Danish Expedition to the Kei Islands station 58
has 18 arms 90 mm. long; of the eight IIBr series present six are 4(3 + 4) and two are 2;
one of the post-radial series bears two arms only. Another has 13 arms 100 mm. long;
of the three IIBr series present two are 4(3 + 4) and one is 2. Another has 13 arms
80 mm. long, there being three IIBr 4(3+4) series. The other two have 10 arms which
in one are 85 mm. kmg.

One of the specimens from the Danish Expedition to the Kei Islands station 59
has 16 arms 100 mm. long; of the six IIBr series present four are 2 and two are 4(3 + 4) ;
the ornamentation is well developed. Another specimen has 10 arms 80 mm. long;
the carination of the IBr series and first two brachials is very low and in conspicuous;
the earlier brachials have strongly produced distal edges, but the brachials are without
median tubercles or carination. A third has 10 arms 70 mm. long; the edges of the
elements of the IBr series and the proximal edge of the axillary are scalloped or tuber-
cular ; the keel on the IBr series and first two brachials is fairly well developed, and the
broad median tubercles and later low blunt keels on the brachials, though very obscure,
may be made out on most of the arms. A fourth specimen has 10 arms about 70 mm.
long; the ornamentation is very slight, the carination on the elements of the IBr series
being scarcely indicated, and the median elevation on the brachials being broad and
exceedingly faint. A fifth specimen has 10 arms 55 mm. long; the elements of the IBr
series and first two brachials are unornamented except for the median keel; the distal
edges of the proximal brachials are thickened and moderately produced; the median
elevation is very slightly marked. Another specimen has 10 arms 95 mm. long; the
ornamentation is typically developed. The three remaining specimens are small with
10 arms which in one are only 25 mm. in length.

A specimen from Siboga station 294 was described under the name of Perissometra
gorgonia in the following terms :

The centrodorsal is small, apparently conical. The cirrus sockets are arranged
in 10 closely crowded columns.

The cirri are XXIV, 19-24 (usually 21), from 25 to 40 (usually between 30 and 35)
mm. long. The cirrus segments are very uniform in length, the sixth and seventh
and following being slightly longer than broad. The distal ends of the segments are
slightly prominent, and the distal ends of those in the outer half are slightly thickened
on the dorsal side.

The ends of the basal rays are visible as very large rhombic or rounded-triangular
low tubercles or flat areas in the angles of the calyx.

The radials are concealed. The IBri are extremely short, in the angles of the
calyx running far upward and meeting over the ends of the basal rays; they bear a
low broad median tubercle. The IBr2 (axillaries) are rhombic, about two and one-
half times as broad as long. Except in the median line their edges, like those of the
IBr,, are slightly everted. They bear a large, low, and broad median tubercle. The
IIBr series are all 4(3+4) ; each of the component ossicles carries a low rounded median
tubercle and has slightly thickened edges all around.

242 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The 20 arms are about 170 mm. long. The earlier brachials have slightly thick-
ened and more or less everted distal edges which as the brachials become triangular
change to simple overlapping distal ends. Traces of a rounded median tubercle may
be found at least as far as the end of the proximal third of the arm.

The specimen from Siboga station 254 has 17 arms 130 mm. long. Of the IIBr
series five are 4(3+4) and two are 2. The cirri are rather slender, XXV, 14-16, 16
mm. long.

One of the specimens from south of the Nicobar Islands, which were referred to G.
gorgonia with some hesitation, is very large but badly broken. The arms were appar-
ently 20 in number. One of the IIBr series is 2, the others being 4(3+4). The edges of
the ossicles of the division series and brachials are much less prominent than in the
specimen from Siboga station 294, while there is scarcely an indication of the median
tubercle beyond the lowest brachials. The cirri have 17-22 segments. With this there
is a very small specimen with 11 arms 50 mm. long, one IIBr 4(3 + 4) series being
developed.

Localities— Menado Bay, Celebes (lat. 1°31' N., long 124°47' E.); 457 meters;
Captain Christiansen, Great Northern Telegraph Co., March 12, 1913 (4, C. M.).

Siboga station 259; Kei Islands (lat. 5°29'12" S., long. 132°52'30" E.) ; 487 meters;
coral sand and dead coral; December 16, 1899 [A. H. Clark, 1912, 1916, 1918, 1929;
Gisle"n, 1927, 1934] (2, U.S.N.M., E. 457; Amsterdam Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortenseu; station 3; 245 meters;
sand; March 31, 1922 (7, U.S.N.M., E. 3203; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 8; 300 meters;
Aprils, 1922 (3, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 12; 320 meters;
sand; April 9, 1922 (5, U.S.N.M., E. 3198; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 245 meters;
May 10, 1922 (2, U.S.N.M., E. 3167; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 58; 290 meters;
May 12, 1922 (5, U.S.N.M., E. 3165; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 59; 385 meters;
coral; May 12, 1922 (9, U.S.N.M., E. 3153; C. M.).

Siboga station 254; East Arafura Sea, west of Taam Island (lat. 5°40' S., long
132°26' E.); 310 meters; fine gray mud; December 10, 1899 [A. H. Clark, 1916, 1918;
Gislen, 1934] (1, U.S.N.M., E. 435).

Siboga station 294; East Timor Sea (lat. 10°12'12" S., long. 124°27'18" E.); 73
meters; soft mud with very fine sand; January 23, 1900 [A. H. Clark, 1916, 1918] (1,
Amsterdam Mus.).

South of the Nicobar Islands; 1,023 meters; cable repair ship Patrol, Eastern and
Associated Telegraph Co. [A. H. Clark, 1929] (2, B. M.).

Geographical range. — From northern Celebes southward to the Kei Islands, the
East Arafura Sea, and the East Timor Sea, and westward to the Nicobar Islands.

History.— Pachylometra crassa was originally described in 1912 from a specimen
from Siboga station 259. On the establishment of the genus Perissometra in 1916
crassa was transferred to it, and in the list of included species Perissometra gorgonia, a
nomen nudum, was given. In. my memoir on the unstalked crinoids of the Siboga

A MONOGRAPH OF THE EXISTING CRINOIDS 243

Expedition published in 1918 Perissometra crassa was redescribed and figured, and
P. gorgonia was described on the basis of a specimen from station 294, notes being given
on another from station 254. In the key to the species of Perissometra, gorgonia was
placed in the section including species with 14-20 (usually 20) arms, while crassa was
placed in the section including species with not more than 13 arms, and was said to
have 10 or 11 stout arms; gorgonia was said to have the bracliials with prominent
swollen and produced distal borders, while in crassa the brachials were said to have an
unmodified dorsal surface; this, however, refers to the absence of median keels or
tubercles, for the figure of crassa shows the brachials with prominent distal ends.

In 1927 Prof. Torsten Gislen wrote that crassa should be referred to the genus
Glyptometra. In 1929 I published notes on two specimens tentatively referred to
Perissometra gorgonia which had been brought up from 560 fathoms south of the Nicobar
Islands by the cable repair ship Patrol, and in the same paper I compared Perissometra
crassa with a new species P. occidental-is. In 1934 Professor Gisl6n listed Perissometra
crassa among the comatulids with the Heteromelra bengalensis type of arm division,
and P. gorgonia among the species with the Comanthus solaster type of arm division.

GLYPTOMETRA INAEQUALIS (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 274, p. 260, 491, p. 367; pt. 2, pi. 3, figs. 986, 987, pi. 27, fig. 1168, pi. 42, figs-
1267-1269, 1273-1275, pi. 44, figs. 1291, 1298, 1299, 1302-1304.]

Antedon inaequalis VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, pp. 18, 30, 31, 55,
70, 73 (Challenger stations 170, 174; myzostomes; women nudum). — P. H. CARPENTER, Challenger
Reports, Zool., vol. 11, pt. 32, 1884, p. 83, pi. 54, fig. 8 (ambulacra! plating of a pinnule). — VON
GRAFF, Challenger Reports, Narrative, vol. 1, pt. 1, 1885, p. 316 (myzostomes). — P. H. CARPENTER,
Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 244 (description; Challenger stations 170A,
174, B, C, or D, 175), pi. 2, figs. 5, a-d; pi. 51, fig. 2; text fig. 5A, p. 246. — BRAUN, Centralbl.
Bakteriol. Parasitenkunde, vol. 3, 1888, pp. 185, 210 (myzostomes; after von Graff). — HUTTON,
Index faunae Novae Zealandiae, 1904, p. 290 (listed). — MINCKERT, Arch. Naturg., Jahrg. 71, 1905,
vol. 1, Heft 1, p. 224 (regeneration). — HAMANN, Bronn's Klassen und Ordnungen des Tier-Reichs,
vol. 2, Abt. 3, 1907, p. 1582 (listed).— A. H. CLARK, Crinoids of the Indian Ocean, 1912, p. 35
(identity). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, pp. 285, 306 (in Granulifera
group; believed a synonym of granulifera), pp. 289, 298 (description; discussion), fig. 2, p. 288,
fig. 36, p. 291, figs. 7, a-d, p. 297.

Antedon inequalis SPRINGER, Mem. Mus. Comp. Zool., vol. 25, No. 1, 1901, p. 45 (tegminal plates).

Charitometra inaequahs A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed);
Smithsonian Misc. Coll., vol. 52, No. 2, 1908, p. 227 (compared with Ch. smithi [distincta]) .

Pachylometra inaequalis A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed) ; Crinoida
of the Indian Ocean, 1912, p. 35 (identity), p. 216 (synonymy; localities); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 48 (published reference to specimens in the B. M. ; Challenger
stations 170, 174, 175); Unstalked crinoids of the Siboga-Exped., 1918, p. 184 (in key; range;
references).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 39 (notes); Vid. Medd.
Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 482; Kungl. Fysiogr. Sallsk. Handl., new ser.,
vol. 45, No. 11, 1934, pp 21, 26.

Diagnostic features. — The cirri are stout with about 20 segments of which all but
the basal are subequal, about as long as broad or somewhat broader than long, and
are arranged in 10 or 15 columns on the centrodorsal ; the division series and arms are
smooth; and the 11-20 arms are 100-145 mm. long.

Description. — The centrodorsal is hemispherical, rather flattened at the dorsal pole.
Carpenter's figure shows the cirri arranged in 3 closely crowded columns of 1 or 2 each
in each radial area.

244 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XX-XXV, about 20. According to Carpenter a few of the segments
are longer than broad and the later ones are somewhat compressed laterally and more
or less distinctly carinate dorsally. In the figure the segments beyond the basal are
about as long as broad except for the last two which are somewhat longer.

The radials are partially visible above the interradial angles of the centrodorsal.
The IBri are short, sharply convex, and very closely united laterally. The IBr2 (axil-
laries) are short, broadly pentagonal, and very convex in the center; a synarthrial
tubercle is present. The IIBr series are 4(3+4). The elements of the IIBr series and
in a lesser degree also those of the IBr series and the fourth brachial are in close lateral
contact and very distinctly wall-sided with sharp edges and the margin of the dorsal
surface a little depressed. The third and occasionally also the fourth brachial may
likewise be slightly flattened on both the outer and inner sides. One specimen has one
IIIBr 2(1 + 2) and one IIIBr 3(2+3) series.

The 11-20 arms are about 100 mm. long and are composed of about 120 brachials of
which the lowest are nearly oblong, those following triangular and as long as broad, the
succeeding becoming more wedge-shaped. The lower parts of the arms and the division
series often have somewhat prominent edges.

On arms arising from a IBr axillary the first syzygy is between brachials 3+4 and
the next is from between brachials 5 + 6 to between brachials 14+15. On arms arising
from a IIBr axillary the first syzygy is usually between brachials 1 + 2 and the second
is from between brachials 8+9 to between brachials 11 + 12. The distal intersyzygial
interval is from 3 to 16, usually from 5 to 8, muscular articulations.

PD is small, 7 mm. long with 20-25 short segments the lowest of which, and espe-
cially, the first, are broad, trihedral, and flattened against the arm, the remainder being
slightly carinate. PI is a trifle longer with relatively long terminal segments and less
broad and more carinate basal segments. P2 and the following pinnules are still longer
and stouter, 12 mm. in length, with the outer edges of the third and two to four following
segments much produced toward the ventral side so as to give them a broad and flat-
tened appearance. After P3 the length of the pinnules decreases somewhat, but the
expansion of their lower segments is traceable until P]5 or P20, after which they become
more slender with only the two basal segments broader than long.

The disk is 10mm. in diameter, much incised and completely plated both along the
ambulacra and at the sides. A pavement of anambulacral plates covers the gonads.
The pinnule ambulacra have well defined side plates alternating with and partly con-
cealing the sacculi, which are mostly small.

The color in alcohol is light whitish brown.

Notes. — After examining the Challenger specimens in the British Museum Gislen
wrote that in this species there are often syzygies between brachials 1+2 and 3+4, hi
other words that the first four brachials are often united in two syzygial pairs. He gives
a diagram of the conditions in a postradial series with two IIBr 4(3+4) series. One
of these gives rise to two arms on one of which the syzygies are between brachials 1+2
and 10+11, while on the other they are between brachials 1+2 and 11 + 12. On the
other IIBr series the inner branch is undivided with syzygies between brachials 1+2,
4+5, 11 + 12, and 17+18. The outer branch is a IIIBr 3(2 + 3) series with the inner
arm having syzygies between brachials 1 + 2, 4+5, 11 + 12, 17 + 18, while the outer
arm has them between brachials 1+2, 8 + 9, 14+15, and 20+21.

A MONOGRAPH OF THE EXISTING CRINOIDS 245

Carpenter said that the number of arms in this species varies very considerably.
Several individuals have 20, but 14 to 16 is not an uncommon number, and two speci-
mens have only 11. IIIBr series occur in two specimens. In one the IIIBr series is
2(1 + 2) and in the other it is 3(2+3).

The Albatross specimen from the Philippines, which is clinging to part of a stem of
Saracrinus acutus, has 20 arms 145 mm. long; of the ten IIBr series eight are 4(3 + 4)
and two are 2. The cirri are XXV, 22-23, with all the segments except the basal about
as long as broad.

Localities. — Challenger station 170 A; near Kermadec Islands (lat. 29°45' S., long.
178°11' W.); 1,152 meters; bottom temperature 4.17° C.; volcanic mud; July 14, 1874
[von Graff, 1884, 1885; P. H. Carpenter, 1884, 1888; Braun, 1888; Springer, 1901;
Button, 1904; Minckert, 1905; Hamann, 1907; A. H. Clark, 1907, 1908, 1909, 1912,
1913, 1918; Hartlaub, 1912; Gislen, 1928, 1934] (3, B. M.).

Challenger station 174 (B, C, or D); near Kandavu, Fiji (lat. about 19°06' S.,
long, about 178°18' E.); 466, 1,115, or 384 meters; bottom temperature (at 1,115
meters) 3.89° C.; coral mud; August 3, 1874 [von Graff, 1884, 1885; P. H. Carpenter,
1884, 1888; Braun, 1888; Springer, 1901; Minckert, 1905; Hamann, 1907; A. H. Clark,
1907, 1908, 1909, 1912, 1913, 1918; Hartlaub, 1912; Gislen, 1928, 1934] (3, M. C. Z.,
268; B. M.).

Philippine Islands; Albatross (1, U.S.N.M., 35896).

Doubtful locality. — Challenger station 175; near Kandavu, Fiji (lat. 19°02' S.,
long. 177°10' E.); 2,468 meters; bottom temperature 2.22° C.; globigerina ooze; August
12, 1874 [von Graff, 1884, 1885; P. H. Carpenter, 1884, 1888; Braun, 1888; Springer,
1901; Minckert, 1905; Hamann, 1907, A. H. Clark, 1907, 1908, 1909, 1912, 1913, 1918;
Hartlaub, 1912; Gislen, 1928, 1934] (1, EM.)."

Geographical range. — From the Philippine Islands to Fiji and the Kermadec
Islands, north of New Zealand.

Bathymetrical range. — One definite and reliable record, 1,152 meters.

Thermal range. — One definite record, 4.17° C.

History. — Antedon inaequalis was first mentioned by Prof. Ludwig von Graff in his
memoir on the myzostomes of the Challenger Expedition published in 1884. The
name as given by him was a nomen nudum. In his report on the stalked crinoids of the
Siboga Expedition published in 1884 Dr. P. H. Carpenter cited Antedon (Poecilometra}
acoela and A. inaequalis, both from station where pentacrinites were abundant, as
good examples of comatulids with the pinnule ambulacra as fully as well or even better
plated than those of the pentacrinites. He gave a so-called specific formula for Antedon
inaequalis, which technically is the equivalent of a description, and figured the am-
bulacral skeleton of a pinnule. In 1885 Professor von Graff again listed Antedon in-
aequalis, and in his report on the comatulids of the Challenger Expedition Dr. Carpenter
hi 1888 described and figured it in detail, listing 12 specimens from station 170A, 5 from
station 174 (B, C, or D), and one broken specimen from station 175, a locality he
regarded as doubtful.

Braun hi 1888 cited Antedon inaequalis as a host for certain myzostomes; Springer
in his study of Uintacrinus published in 1901 mentioned the tegminal plates; Hutton
in 1904 listed it as a New Zealand species; Minckert in 1905 discussed the arrangement
of the syzygies; and it was listed by Hamann in 1907.

246 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In my first revision of the old genus Antedon published in 1907 Antedon inaequalis
was transferred to the new genus Charitometra, and in 1908 I compared Charitometra
inaequalis with a new species, Ch. smithi. On the establishment of the genus Pachylo-
metra in 1909 inaequalis was transferred to it. In my memoir on the crinoids of the
Indian Ocean published in 1912 Pachylometra inaequalis was listed and the range and
synonymy were given, and in 1913 I gave notes on the Challenger specimens I had
examined at the British Museum — two from station 174, one from station 175, and
three from station 170. In 1918 in my report on the unstalked crinoids of the Siboga
Expedition inaequalis was included in the key to the species of Pachylometra and the
synonymy and range were given. In 1928 Prof. Torsten Gislen published additional
notes on the specimens in the British Museum, and in 1934 he listed Pachylometra
inaequalis among those comatulids with the Perissometra macilenta type of arm divi-
sion, and also among those with the Crossometra septentrionalis type of arm branching.

GLYPTOMETEA SEPTENTRIONAUS (A. H. Clark)

[See vol. 1, pt. 1, fig. 369, p. 299; pt. 2, fig. 675, p. 335.]

Charitometra distincla A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 312 (Sagami Bay).

Pachylometra septentrionalis A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 554 (description,
based upon the preceding); Proc. Biol. Soc. Washington, vol. 25, 1912, p. 78 (compared with
P. helius); Crinoids of the Indian Ocean, 1912, p. 215 (synonymy; locality); Journ. Washington
Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance).

Crossometra septentrionalis A. H. CLAKK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606
(listed); Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with C. helius), p.
175 (in key; range), p. 176 (references). — GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4,
vol. 5, No. 6, 1922, p. 119 (Bock's station 36; notes), figs. 77,78, p. 88; Zool. Bidrag Uppsala, vol.
9, 1924, pp. 44, 71, 80, fig. 80, p. 81 (syzygial face) , fig. 109, p. 93 (synarthrial face) ; Kungl. Fysiogr.
Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 26.

Crossometra distincta GISL&N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 120.

Diagnostic jeatures. — The proximal portion of the animal is very broad, the profile
of the division series and arm bases being strongly convex; the ossicles of the division
series and first two brachials each bear a more or less developed low rounded tubercle;
the distal cirrus segments are broader than long and bear dorsally a high narrow sharp
keel the crest of which is parallel to the longitudinal axes of the segments ; the 33 arms
are 130 mm. long; and the cirri have 19-23 segments.

Description. — The centrodorsal is very rounded conical, broader at the base than
high, with the bare polar area very small, 1 mm. in diameter, and surrounded by 5 small
radial tubercles. The cirrus sockets are arranged in 10 closely crowded columns of
2 or 3 each.

The cirri are XX, 19-23, about 35 mm. long, very stout, and in lateral view in-
creasing considerably in width in the outer portion. The first segment is short, twice
as broad as long, and the following gradually increase in length to the fourth which is
about as long as broad. The succeeding segments are similar to the fourth, the terminal
becoming slightly broader than long. The penultimate segment is of less width than
those immediately preceding, and is half again as long as broad. On the fourth or
fifth segment the dorsal surface becomes rounded carinate, this carination slowly
becoming higher and sharper, on the distalmost 10 or 12 standing out as a high narrow
sharp keel the distal portion of the profile of the crest of which in lateral view is seen

A MONOGRAPH OF THE EXISTING CRINOIDS 247

to be parallel to the longitudinal axes of the segments. The opposing spine is small,
but prominent, and terminal in position.

The ends of the basal rays are very prominent in the interradial angles of the calyx.

The radials are concealed by the centrodorsal. The IBri are very short, cresccntic,
the lateral edges thickened and more or less everted, and the proximal edge thickened
and more or less tubercular or crenulate; a rather high, strongly rounded, dorsoven-
trally elongate tubercle occupies the median dorsal line. The IBr2 (axiharies) are tri-
angular, twice as broad as long, with a high median tubercle resembling that on the
IBri the distal portion of which bends to one side or the other reaching almost or quite
to the base of the IIBrj. Of the 10 IIBr series present 9 are 4(3 + 4) and one is 2.
They are strongly and evenly convex dorsally. The 2 distal elements are slightly
separated interradially by the carinatc basal segments of Pu. The ossicles of the IIBr
series bear rounded median tubercles similar to those on the IBr series, but somewhat
less high. The IIIBr series are 2(1+2), developed internally in 1, 2, 2, 1 order. Two
IVBr series are present, both 2(1+2), one internal in reference to the preceding IIIBr
series, the other internal in reference to the preceding IIBr series. The lower part of
the animal is broad and stout and broadly rounded so that the profile resembles in
general that of the larger species of Crinometra.

The 33 arms are 130 mm. long. The proximal oblong brachials have a slight trace
of a low median tubercle, and the outer brachials overlap slightly.

Notes. — Professor Gislen says that in the single specimen from Bock's station 36
the centrodorsal is rounded conical, the free dorsal pole without tubercles, 3 mm.
broad at the base and 1.5 mm. high. The cirrus sockets are arranged in a single or
double row, and in 10 columns.

The cirri are XIX, 14-16, from 14-17 mm. long, and are very stout. The fifth
segment is the longest, half again as long as broad. From the eighth segment onward
there is a dorsal longitudinal crest. The ventral margin of the distal segments is about
as long as the width. The opposing spine is in height equal to one-third the width of
the segment. The terminal claw is curved and somewhat longer that the preceding
segment.

The basals project as large mterradial prominences.

The radials are eight times as broad as long and bear a median tubercle. The
IBn are five times as broad as long and are laterally united. The IBr2 (axillaries) are
three times as broad as long. There is a median tubercle on the IBri and on the proxi-
mal portion of the IBr2, and similar tubercles on the ossicles of the IIBr series. The
IIBr series are 4(3+4). The IIIBr series are 2, developed internally. The elements
of the IIIBr series and the first two brachials have slight median tubercles. The first
segments following each axillary are united internally.

The 18+ arms are 70 mm. long. The first 12 brachials are discoidal, those follow-
ing wedge-shaped. The distal brachials have a low dorsal spine which does not overlap
that on the brachial succeeding. The brachials are sharply flattened laterally as far
as the twelfth. The bases of the PD are visible between the arm bases.

The first syzygy on the inner side is usually between brachials 1 + 2; the distal
intersyzygial interval is 4 oblique muscular articulations.

PD is about 5 mm. long with 22 segments which are thickened and bear dorsal
prominences similar to those found in the family Calometridae. The first segment is

248 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

twice as broad as long; the seventh and following segments are more slender and are a
little flattened. The distal segments are about as long as, or a little longer than,
broad.

PI is 4 mm. long with about 18 segments. P2 is 3.2 mm. long with 14 segments.
The distal pinnules are 4.5 mm. long with 13-14 segments of which the first two and
the last two are short, the others from two to two and one-half tunes as long as broad.

The disk is 4 mm. in diameter, not completely regenerated, very closely and coarsely
granulated, shrunken, and somewhat incised.

The color in alcohol is white, the disk dark brown.

Professor Gislen identified this specimen as a young individual of Crossometra
septentrionalis.

Localities. — Sagami Bay, Japan; Alan Owston, yacht Golden Hind [A. H. Clark,
1908, 1911, 1912, 1915, 1916, 1918] (1, U.S.N.M., 27502).

Dr. Sixten Bock's Expedition to Japan 1914, station 36; Misaki, Sagami Bay,
Japan; directly off shore; 366 meters; July 1, 1914 [Gislen, 1922, 1924, 1934].

History. — The first known specimen of this species was found in a collection of
Japanese crinoids dredged by Alan Owston, of Yokohama, in his yacht the Golden Hind
and subsequently purchased by Frank Springer, who presented it to the National
Museum. It was recorded in 1908 under the name of Charitometra distincta (P. H.
Carpenter). The original label had been lost, so the locality was given simply as
"Sagami Bay."

The receipt of several specimens of true distincta from the Philippines showed that
the Japanese specimen represented a wholly different species, so in 1911 it was described
under the name of Pachylometra septentrionalis. In 1912 P. septentrionalis was com-
pared with the new species P. helius, and in my memoir on the crinoids of the Indian
Ocean published later in the same year it was listed and the synonymy and range were
given. In 1915 it was listed as a southern Japanese species with the locality. On the
establishment of the genus Crossometra in 1916 septentrionalis was transferred to it.
In my memoir on the unstalked crinoids of the Siboga Expedition septentrionalis was
included in the key to the species of Crossometra, the locality was given, and it was
compared with C. helius.

Prof. Torsten Gislen in 1922 recorded and gave notes on a second specimen that
had been dredged off Misaki in 200 fathoms by Dr. Sixten Bock. He added: "Though
the species-name Or. distincta is older still, in conformity with A. H. Clark, I do not
wish to use it, partly because it is a nomen nudum, partly because the name distincta
was given by P. H. Carpenter to a species in the closely-related genus Pachylometra
(Clark did not separate this genus from Crossometra before 1918)."

In my first reference to this species in 1908 the specific name distincta was credited
to Carpenter, and was not a nomen nudum. Gislen's slip is probably explained by his
inability to understand how I ever could have identified a specimen of septentrionalis
with a species as widely different as Carpenter's distincta.

In 1924 Gislen described and figured various details of the arm structure of his
specimen, and in 1934 he discussed the significance of the arm branching of the species.

A MONOGRAPH OF THE EXISTING CRINOIDS 249

GLYPTOMETRA DISTINCTA (P. H. Carpenter)

PLATE 23, FIGUBES 70-72; PLATE 24, FIGURE 73

[See also vol. 1, pt. 2, figs. 227, p. 183, 245, p. 199, 529, 530, p. 287, 672, p. 335, 760, p. 353, 817,
818, p. 385, 819, p. 392, 831-834, p. 405, 856, p. 412.]

Antedon dislincta P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 247 (descrip-
tion; Challenger station 210), pi. 51, fig. 1. — HAMANN, Bronn's Klassen und Ordnungen des
Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1582 (listed). — A. H. CLARK, Crinoids of the Indian Ocean,
1912, p. 35 (identity). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, pp. 285, 306
(in Granulifera group; believed synonym of granulifera).

Charitometra dislincta A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed). —
A. H. CLARK, Smithsonian Misc. Coll., vol. 52, No. 2, 1908, p. 227 (compared with Ch. smithi).

Charitometra smithi A. H. CLARK, Smithsonian Misc. Coll., vol. 52, pt. 2, 1908, p. 227 (description;
Albatross station 5123; also stations 5116, 5198); Unstalked crinoids of the Siboga-Exped., 1918,
p. 184, footnote, p. 185 (synonym of distincta).

Pachylometra distincta A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed); Proc.
U. S. Nat. Mus., vol. 39, 1911, p. 554 (comparison with P. [Crossometra] seplentrionalis) , p. 555
(Albatross stations 5510, 5536; characters); Crinoids of the Indian Ocean, 1912, p. 35 (identity),
p. 216 (synonymy; localities); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 48 (published
reference to specimen in the B. M.; Challenger station 210); Unstalked crinoids of the Siboga-
Exped., 1918, p. 184 (in key; range), p. 185 (synonymy); Smithsonian Misc. Coll., vol. 72, No. 7,
1921, pi. 2, fig. 29 (side plates), figs. 30, 31 (side and covering plates). — GISL£N, Vid. Medd.
Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 482; Kungl. Fysiogr. Sallsk. Handl., new ser.,
vol. 45, No. 11, 1934, pp. 21, 26.

Pachylometra smithi A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed); Proc.
U. S. Nat. Mus., vol. 39, 1911, p. 557 (Albatross stations 5282, 5348; correction of dimensions
given in the original description); Crinoids of the Indian Ocean, 1912, p. 220 (synonymy; range).

Pachylometra selene A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 556 (description; Albatross
station 5523; compared with P. investigatoris); Crinoids of the Indian Ocean, 1912, p. 219
(synonymy; locality).

Perissometra selene A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. 177 (in key; range), p. 179 (references). —
GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22.

Crossometra distincta GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 34 (notes).

Diagnostic features. — The cirri have 17-26 (usually about 20) segments and are
20-30 (usually 20-25) mm. long; the earlier segments are markedly longer than broad
and the distal are broader than long; the cirrus sockets are arranged in 10 columns on
the centrodorsal ; the 14-33 (usually 20-25) arms are 100-205 mm. long; the IIBr series
are all or mostly 4(3 + 4); and the division series and arm bases are smooth.

Description — As described by Carpenter the centrodorsal is a thick disk with the
interradial angles somewhat produced. The cirri, as determined by Gislen from an
examination of the type specimen in the British Museum, are arranged in 10 columns,
2 in each radial area.

The cirri are about XXV, about 20. The sixth and seventh segments are the
longest, according to the figure from slightly longer than broad to half again as long
as broad. The segments following are shorter and gradually develop a dorsal keel,
and according to the figure a slight tubercle in the. middle of the dorsal side of the
distal end.

843803—50

250 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The radials are concealed. The IB^ are short and much curved, and the IBr2
(axillaries) are subtriangular, both ossicles being very convex with a rather sharp
dorsal ridge. The IIBr series are 4(3 +4), with the first two ossicles very convex at their
junction. The IIIBr series, when present, are 2(1+2). The elements of the IBr
series and the first two elements of the IIBr series are in close lateral contact with
sharp lateral edges and flattened sides. In the middle of the postradial series this
feature is continued on to the IIBr axillary and the first five or six brachials, but on
the outer sides the IIBr axillaries are prevented from meeting those of adjacent post-
radial series by the pinnule of the IIBr2, which is placed very near the dorsal surface.

The 27 arms of the type specimen are 100 mm. long. The first twelve brachials
are nearly oblong, and those following are more triangular, gradually becoming longer
than broad.

Syzygies occur between brachials 1+2, and again between about brachials 26 + 27.
The distal intersyzygial interval is from 6 to 15, usually from 8 to 11, oblique muscular
articulations.

PD is rather slender, about 8 mm. long with about 30 small, compressed, and slightly
carinate segments. The pinnules following are similar, decreasing slightly in size to
about P3 after which the next eight or ten pinnules on each side have the lower segments
carinate and expanded on the outer side, with the outer ones more styliform. This
feature gradually dies out, and the pinnules become more slender and elongated.

The disk and brachial ambulacra are well plated. The pinnule ambulacra have
well defined side plates which alternate with the sacculi.

The color in alcohol is light whitish brown with patches of brownish gray.

Notes. — After examining the type specimen in the British Museum I wrote that
it resembles those in the National Museum from the Philippines. After studying the
same specimen Gislen decided that distincta, assigned by me to the genus Pachylometra,
must be referred to Crossometra as it has the cirri arranged in 10 columns.

In 1908 I described Charitometra smithi from a specimen from Albatross station
5123 in the following terms.

The centrodorsal is thick discoidal or short columnar with the cirrus sockets ar-
ranged in 2 rows and roughly in 3 irregular columns in each radial area, though the
middle column is sometimes lacking.

The cirri are XXVII-XXX, 19-22 (usually 20), 20-25 mm. long. The first seg-
ment is very short, the second is about twice as broad as long, the third is about as long
as broad, the fourth is slightly longer than broad, and the fifth is nearly half again as
long as broad. The following segments decrease very gradually hi length, the tenth
and following being about as long as their distal width. The segments after the eighth
or ninth become rounded carinate dorsally, soon developing rather prominent rounded
tubercles situated on the dorsal distal edge. The opposing spine, though prominent, is
small, terminally situated, reaching a height equal to about half the width of the penul-
timate segment or rather less, its base occupying only the distal third of the segment.
The terminal claw is about as long as the penultimate segment, rather stout and moder-
ately curved.

The ends of the basal rays are just visible as more or less irregular tubercles in the
angles of the calyx.

A MONOGRAPH OF THE EXISTING CRINOIDS 251

The radials are concealed in the median line of the arm, though sometimes slightly
visible over the ends of the basal rays. The IBrt are very short, three or four times as
broad as long, chevron-shaped, laterally in close apposition, and with the dorsal sur-
face coarsely rugose. The IBr2 (axillaries) are triangular, rather more than twice as
broad as long, with the dorsal surface rugose. The IIBr series are 4(3+4), rarely 2.
The IIIBr series are 2(l-|-2), as a rule developed interiorly in 1, 2, 2, 1 order. The IBr:
is more or less covered with small crowded tubercles, but the remaining ossicles of the
division series are perfectly smooth. The division series and proximal six or eight
brachials are in close apposition and sharply flattened laterally.

The 28 arms of the type are 160 mm. long. The proximal twelve or four teen brachials
are oblong, about twice as broad as long, those following becoming triangular and nearly
as long as broad, and in the distal part of the arm wedge-shaped and longer than broad.

The first syzygy is usually between brachials 1 + 2, but may be between brachials
3+4, especially in arms arising directly from a IIBr axillary. On arms in which bra-
chials 1+2 are united by syzygy there is often a syzygy between brachials 3+4. The
next syzygy is near brachials 19+20 to brachials 25+26 (usually between brachials
20 + 21 or a few segments further on), and the distal intersy/ygial interval is from 4 to
12 (usually 6 or 7) oblique muscular articulations.

PD is slender and evenly tapering, becoming flagellate distally, 13 mm. long with
about 45 segments of which those in the proximal half are about half again as broad as
long and those hi the distal about as long as broad. PI is similar but only about 9 mm.
long with 35 segments the first five of which are noticeably carinate. P2 is of about
the same length but consists of only about 25 segments the first four or five of which
are carinate and slightly broader than those of PI; the terminal segments are about
twice as long as broad. In the pinnules following the segments, except the first two,
gradually become longer and fewer in number. Pj0 is 8 mm. long with 17 segments of
which the first two are not so long as broad and bear a triangular or bluntly triangular
process distally and the remainder are about as long as broad, gradually becoming
slightly longer than broad; the third to seventh or eighth segments are very slightly
enlarged, protecting the gonads, but the enlargement is not very noticeable and tapers
evenly in both directions. The distal pinnules are 9 mm. long with 17-18 segments of
which the first is short and wedge-shaped, the second is not quite so long as broad, and
the remainder are about half again as long as broad.

In alcohol the arms and cirri are yellow, the calyx, division series, and first four or
five brachials dark brown.

In 1916 I described a specimen from Albatross station 5523 under the name of
Perissometra selene in the following terms.

The centrodorsal resembles that of G. investigatoris.

The cirri are XXX, 17-19, from 25 to 30 mm. long, much shorter and with fewer
segments than those of G. investigatoris. The segments in the outer half have rather
strongly produced distal dorsal edges which bear a rounded tubercle hi the median line
so that the dorsal profile of the cirri is strongly serrate.

The division series and arm bases diverge, as in <?. investigatoris, and are only slightly
convex dorsally, not so much so even as in that species ; each ossicle is smooth and even
dorsally, but bears in its center a very prominent high rounded tubercle; these tubercles

252 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

gradually become obsolete after the proximal quarter of the arms, but may be traced
as far as the beginning of the distal half. Two of the IIBr series are 4(3+4) and two
are 2. There are no IIIBr series present.

The 14 arms are 205 mm. long.

Another specimen from Albatross station 5523 has 20 arms 195 mm. long. Of the
ten IIBr series nine are 4(3+4) and one is 2. The cirri are XXX, 17-21 (usually 18-19) .
The tubercles on the division series and lower brachials are not quite so prominent as
in the type specimen.

Of the four specimens from Albatross station 5510 one has 21 arms 130 mm. long and
the cirri 20-25 mm. long; another has 29 arms with the IIIBr series 2(1 + 2), internally
developed; a third has 24 arms.

The single fine specimen from Albatross station 5536 has 23 arms 160 mm. long and
the cirri XXVI, 19-24, 23-25 mm. long; all the IIBr series are 4(3+4) ; the three IIIBr
series are 2(1+2), developed internally. The genital pinnules bear eggs.

From Albatross station 5348 there are 22 medium sized or small specimens with
19-22 arms which in the larger are from 125 to 135 mm. long.

Of the three specimens from Albatross station 5282 one has 25 arms 150 mm. long;
another has 30 arms 140 mm. long, one IIBr series dividing both internally and exter-
nally and another not dividing at all; and the third has 33 arms 110 mm. long, three
of the internally developed IIIBr series bearing on the innermost side IVBr 2(1+2)
series.

The specimen from Menado Bay, Celebes, is small with apparently 20 arms; of
the ten IIBr series nine are 4(3+4) and one is 2.

The specimen from the Danish Expedition to the Kei Islands station 51 has 19
arms 130 mm. long; of the IIBr series five are 4(3+4) and four are 2.

The specimen from the Danish Expedition to the Kei Islands station 52 has 20
arms 140 mm. long. Of the IIBr series five are 4(3 + 4) and five are 2. The cirri
have 20-26 (usually 20-23) segments.

Localities. — Albatross station 5282; China Sea in the vicinity of southern Luzon;
Malavatuan Island (N.) bearing S. 84° W., 6.20 miles distant (lat. 13°53'00" N., long.
120°26'45" E.); 453 meters; bottom temperature 8.55° C.; dark gray sand; July 18,
1908 [A. H. Clark, 1911] (2, U.S.N.M., 35720).

Albatross station 5116; Verde Island Passage; Sombrero Island bearing N. 69° E.,
2.50 miles distant (lat. 13°41'00" N., long. 120°47'05" E.); 366 meters; bottom
temperature 10.11° C.; January 20, 1908 [A. H. Clark, 1908] (14, U.S.N.M., 35721).

Albatross station 5123; east coast of Mindoro; Malabrigo Light bearing N. 44° W.,
32.50 miles distant (lat. 12°12'45" N., long. 121°38'45" E.); 517 meters; green mud;
February 2, 1908 [A. H. Clark, 1908, 1909, 1911, 1912] (1, U.S.N.M., 25448 [type]).

Albatross station 5348; Palawan Passage; Point Tabonan bearing S. 89° E., 33.5
miles distant (lat. 10°57'45" N., long. 118°38'15" E.); 685 meters; bottom tempera-
ture 13.44° C.; coral sand; December 27, 1908 [A. H. Clark, 1911] (20, U.S.N.M.,
35681).

Albatross station 5198; in the vicinity of western Bohol; Baliscasag Island bearing
S. 6° E., 10.25 miles distant (lat. 9°40'50" N., long. 123°39'45" E.); 402 meters;
bottom temperature 12.17° C.; green mud; April 9, 1908 [A. H. Clark, 1908] (1,
U.S.N.M., 35719).

A MONOGRAPH OF THE EXISTING CRINOIDS 253

Challenger station 210; off Panglao and Siquijor Islands (lat. 9°26' N., long.
123°45' E.); 685 meters; bottom temperature 12.26° C.; blue mud; January 25, 1875
[P. H. Carpenter, 1888; Hamann, 1907; A. H. Clark, 1907, 1908, 1909, 1911, 1912,
1913, 1918, 1921; Gisle"n, 1928, 1934; Hartlaub, 1912] (1, B. M.).

Albatross station 5536; between Negros and Siquijor; Apo Island (C.) bearing
S. 26° W., 11.8 miles distant (lat. 9°15'45" N., long. 123°22'00" E.); 510 meters;
bottom temperature 11.94° C.; green mud; August 19, 1909 [A. H. Clark, 1911] (1,
U.S.N.M., 35703).

Albatross station 5523; off northern Mindanao; Point Tagolo Light bearing S. 48°
W., 6.7 miles distant (lat. 8°48'44" N., long. 123°27'35" E.); no depth or temperature
given; August 10, 1909 [A. H. Clark, 1911, 1912, 1916, 1918; Gislen, 1934] (2, U.S.N.M.,
27504 [type], 36001).

Albatross station 5510; in the vicinity of northern Mindanao; Camp Overton Light
bearing S. 68° E., 9.1 miles distant (lat. 8°16'00" N., long. 124°03'50" E.); 773 meters;
bottom temperature 11.66° C.; gray mud and fine sand; August 7, 1909 [A. H. Clark,
1911] (3, U.S.N.M., 35718).

Menado Bay, northern Celebes (lat. 1°31' N., long. 124 °47' E.); 457 meters;
Captain Christiansen, Great Northern Telegraph Company, March 12, 1913 (1, C.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 51 ; 348 meters;
mud; May 7, 1922 (1, C.M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 52; 252 meters;
mud; May 7, 1922 (1, U.S.N.M., E. 3152).

Geographical range. — From southern Luzon, Philippines, southward to the Kei
Islands.

Bathymetrical range. — From 252 to 773 meters.

Thermal range. — From 8.55° to 13.44° C.; the average of seven records is 11.42° C.

History. — Antedon distincta was described and figured by Dr. P. Herbert Carpenter
in his report on the comatulids of the Challenger Expedition published in 1888, on the
basis of a specimen from station 210. It was listed by Dr. Otto Hamann in 1907,
and in the same year in my first revision of the old genus Antedon it was transferred
to the new genus Charitometra.

In 1908 I described Charitometra smithi from a specimen from Albatross station
5123, at the same time recording other specimens from stations 5116 and 5198. On
the establisliment of the new genus Pachylometra in 1909 both diMincta aad smithi
were transferred to it. In 1911 in a paper on a collection of crinoids made by the
Albatross in the Philippines I recorded and gave notes on four specimens of Pachylometra
distincta from station 5510 and one, on which the genital pinnules bore eggs, from
station 5536; I remarked that the most striking characteristic of this species is its
slenderness, especially the slenderness of the cirri, the long proximal segments of
which are twice as long as broad. I briefly described Pachylometra selene from a
specimen from station 5523, and recorded and gave notes on 3 specimens of Pachylo-
metra smithi from station 5282, 22 from station 5348sand remarked that in the original
description of this species the arm length was given as 60 mm., an error for 160 mm.
In my memoir on the crinoids of the Indian Ocean published in 1912 Pachylometra
distincta, P. smithi, and P. selene were listed and their synonymies and ranges were
given. In my paper on the crinoids of the British Museum published in 1913 I remarked

254 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

that the type specimen of Antedon distincta in the Challenger collection resembles others
in the U. S. National Museum from the Philippine Islands. On the establishment of
the new genus Perissometra in 1916 selene was transferred to it. In my report on the
unstalked crinoids of the Siboga Expedition published in 1918 selene was included in
the key to the species of Perissometra and the synonymy and range were given; at the
same time distincta was included in the key to the species of Pachylometra, the range
and synonymy were given, and Charitometra smithi was included as a synonym under it.
In 1921 in a popular account of the recent crinoids I figured the side plates and the
side and covering plates of Pachylometra distincta. These figures were taken from Part
2 of the present work, figure 29 being a reproduction of figures 833 and 834, page 405,
and figures 30 and 3 1 being reproductions of figures 832 and 83 1 on the same page.

After examining the type specimen of Antedon distincta Prof. Torsten Gislen
wrote in 1928 under Crossometra distincta that this species which I ranged in the genus
Pachylometra must be referred to Crossometra as it has the cirri arranged hi 10 columns
(or, as he gave it, rows). In 1934 Professor Gislen listed Perissometra selene among
the comatulids with the Comanthus solaster type of arm branching, and placed Pachylo-
metra distincta both among those species with the Perissometra macilenta type of arm
division, and among those with the Crosscmetra septentrionalis type of arm division.

GLYPTOMETRA INVESTIGATORIS (A. H. Clark)

PLATE 24, FIGURES 74, 75; PLATE 25, FIGURES 76-78
[See also vol. 1, pt. 2, figs. 226, p. 180, 537, 538, p. 289, 673, p. 335, 867, p. 419.]

Pachylometra investigatoris A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 82 (description;

Malay Archipelago; 30 fathoms); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 556 (compared with

P. luna and P. selene); Crinoids of the Indian Ocean, 1912, p. 216 (synonymy; detailed descrip-
tion; locality), fig. 39, p. 217.
Pachylometra luna A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 556 (description; Albatross

station 5325; comparisons); Crinoids of the Indian Ocean, 1912, p. 219 (synonymy; locality).
Pachylometra hetius A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 78 (description;

Siboga station 254).
Crossometra helius A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (listed);

Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with C. septentrionalis), p.

174 (in key; range), p. 175 (detailed description; references; station 254), p. 274 (listed), pi.

24, fig. 67; Treubia, vol. 14, livr. 2, December 1933, p. 207 (previous records), p. 214 (Bali Sea;

notes). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 26.
Crossometra investigatoris A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606

(listed); Unstalked crinoids of the Siboja-Exped., 1918, p. 174 (in key; range), p. 175 (references;

notes; station 297), p. 275 (listed). — GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45,

No. 11, 1934, p. 26.

Diagnostic features. — The cirri, which are arranged in 10 columns on the centro-
dorsal, have 20-31 (most commonly 22-27) segments, and are 25-47 (most commonly
30-35) mm. long; the proximal segments are longer than broad and the distal are about
as long as broad or slightly broader than long; the 18-32 (most commonly 26-30) arms
are 110-170 mm. long; and the division series and proximal brachials are smooth.
There seems to be little real difference between this species and G. distincta.

Description.' — The centrodorsal is a truncated cone 7 mm. broad at the base and
5 mm. high. The cirrus sockets are arranged in two columns of from 3 to 5 each in each
radial area, the two columns of each area being separated by a narrow median line not

A MONOGRAPH OF THE EXISTING CRINOIDS 255

quite so broad basally as the sockets, distally narrowing and ending in a point at about
the level of the third or fourth cirrus socket. The columns of each radial area are
closely crowded against, and tend to alternate with, the columns of the adjacent areas.

The cirri are XL, 25-26, about 40 mm. long. The first segment is very short,
the second and third are equal in size, about twice as broad as long, the fourth is slightly
longer, the fifth is as long as broad, and the sixth, seventh, and eighth are the longest,
from slightly longer than broad to about one-third again as long as broad ; those follow-
ing very gradually decrease in length so that those in the distal half are about as long
as broad, or in some cases slightly broader than long. The third segment from the
distal end of the cirri is slightly longer than broad; the antepenultimate segment is
about one-third again as long as broad; the penultimate segment, which is somewhat
less in diameter than the segment preceding, is half again as long as broad. The
distal dorsal edges of the outer segments show an inclination to develop low blunt
tubercles. The opposing spine is represented by a small blunt tubercle, terminally
situated. The terminal claw is long, about as long as the penultimate segment, and is
moderately curved. The cirri are rounded in cross section proximally and moderately
compressed in the distal two-thirds. There is no trace of dorsal carination.

The ends of the basal rays are visible as large rhombic tubercles in the angles of the
calyx.

The radials are concealed. The IBri are short, four or five times as broad as
long, chevron-shaped, in close lateral apposition, and have more or less wavy proximal
and distal borders ; the apposed edges are somewhat thickened and produced, and there are
a few low and broad tubercles on the distal border. The IBr2 (axillaries) are rhombic,
twice as broad as long, rising to a rather sharp dorsoventrally elongated tubercle with
the IBri. The IIBr series are 4(3+4); on three of the IIBr series the syzygy between
the two outer elements is replaced by a synarthry. The IIIBr series are 2(1+2),
developed interiorly. The division series are strongly rounded dorsally and have a
slightly indicated median carination; they are in very close lateral apposition and
their lateral edges are slightly produced and everted.

The 32 arms are 150 mm. long. The first two to four brachials are oblong, short,
united in syzygial pairs which are not quite so long as broad. The two or three follow-
ing brachials are oblong, somewhat over twice as broad as long, those succeeding
becoming wedge-shaped, twice as broad as long, and slightly longer and more oblique
after the proximal third of the arm, when the brachials develop slightly prominent
distal ends.

PD is from 17 to 20 mm. long, very slender and flagellate distally, composed of
50-53 segments, of which the two first are disproportionately large, twice as broad as
long, and are strongly flattened exteriorly, the third is about half as broad as the first
and half as long as the second, twice as broad as long, and those following to the fif-
teenth decrease in diameter and increase in length, being at first twice as broad as long
but becoming after the fifteenth uniformly small and about as long as broad. PI is of
about the same length with 45 segments, similar but much less stout basally and not
tapering so rapidly. P2 is 13 mm. long with about 30 segments, about as stout basally
as the preceding pinnule but tapering much more gradually; the first eight segments
are about three times as broad as long, those following gradually becoming longer and
about as long as broad on about the eighteenth, and terminally longer than broad.

256 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

P3 is about 15 mm. long, and P4 is 16 or 17 mm. long, resembling P2. PS is similar, 13
mm. long. Pa is similar and of the same length. P7 and the following pinnules are 12
mm. long with the segments on the proximal two-thirds slightly expanded laterally.
In the course of the following four or five the pinnules decrease in length to 8 mm., while
the expansion of the segments becomes more pronounced, beginning on the second,
reaching a maximum on the fourth or fifth, then gradually dying away distally. The
distal pinnules are 10 mm. long and stout, as in the other species of the genus.

Side- and covering-plates are well developed. The disk is completely covered by
a pavement of small plates.

Notes. — The specimen from Albatross station 5325 was described as a new species
under the name Pachylometra luna in the following terms.

The centrodorsal is as in P. investigatoris, but is proportionately shorter; the cirrus
sockets are arranged in 10 columns of 2 or 3 each.

The division series and arm bases are essentially as in P. investigatoris, but the
basal rays are much larger, rhombic, entirely concealing the radials in the interradial
angles of the calyx. The division series and arm bases make a slightly greater angle
with the dorsoventral axis than in G. investigatoris, though in general the shape and
proportions are the same. The division series are more convex dorsally than are those
of G. investigatoris, and the center of each in the median dorsal line rises into a broadly
rounded tubercle instead of being obscurely carinate as in G. investigatoris. Similarly,
indistinct broad tubercles occur on the oblong proximal brachials. The interradial
angles are slightly more deeply excavated than are those of G. investigatoris. All the
IIBr series are 4(3 + 4) and all the IIIBr series are 2(1+2), all but a single one of the
latter being developed internally.

The 29 arms of the type specimen are 150 mm. long.

One of the specimens from off Zamboanga has 27 arms 180 mm. long. All the
IIBr series are 4(3+4) and there are seven IIIBr 2 series, all internally developed.
The proximal profile of the division series and arm bases is broadly rounded. The
centrodorsal is large, conical, with the cirrus sockets in 10 columns of 4 each. The two
columns in each radial area are closely crowded against those of the adjacent radial
areas and are separated in the midradial line by a bare area about the width of a cirrus
socket or somewhat less. The cirri are XL, 24-27, from 45 to 50 mm. long. The first
segment is very short, the third is about twice as broad as long, the sixth is about as
long as broad, and the eighth and following are about one-third again as long as broad.
Toward the end of the cirri the segments often become slightly shorter, but the last
two are longer again, the penultimate usually half again as long as broad. The outer
segments are more or less sharply carinate dorsally. This specimen is larger than the
largest in the type series of helius from Siboga station 254 but does not appear to differ
from them in any essential particular.

Another specimen from off Zamboanga has 29 arms 170 mm. long; there are ten
IIBr 4(3 + 4) series and nine IIIBr 2 series, the latter all internally developed. The
cirri are XXX, 23-24, up to 40 mm. long; the outer cirrus segments are more or less
carinate.

A third specimen from off Zamboanga has 30 arms, ten IIIBr 2 series being present,
all internally developed.

A MONOGRAPH OF THE EXISTING CRINOIDS 257

One of the specimens from Menado Bay, Celebes, is large with 22 arms; eight of
the IIBr series are 4(3+4) and one is 2. There are three IIIBr 2 series, all internal.
The cirri have 18-19 segments of which the longest are about as long as broad or slightly
broader than long, and the outer are broader than long. The second specimen is
similar. There are three IIBr 2 series, the other seven being 4(3 + 4). The longest
cirri have 19 segments of which the longest are broader than long and the outer are
from half again to twice as broad as long. The third specimen is much broken.

A specimen from Siboga station 254 was described as a new species under the name
of Pachylometra helius in the following terms :

The centrodorsal is of moderate size, flattened hemispherical or thick truncated
conical, 6 mm. in diameter at the base, 3 mm. across the flat dorsal pole, and 4 mm.
high. The cirrus sockets are arranged in 10 evenly spaced columns of 2 or 3 each.

The cirri are about XXV, 23, about 28 mm. long. The first segment is short,
those following gradually increasing in length to the fifth and sixth, which are the
longest, between one-third and one-half again as long as broad. The. segments following
very slowly decrease in length so that those in the distal third of the cirri are about as
long as the distal width. In the distal third of the cirri the median portion of the distal
dorsal edge of the segments is somewhat swollen, this swelling on the last five or six
before the penultimate becoming a blunt subterminal dorsal tubercle. The opposing
spine is prominent, short, sharp, terminal, and directed obliquely forward.

The ends of the basal rays are visible as large rhombic tubercles in the angles of the
calyx.

The radials are entirely concealed. The IBi'i are very short, broadly V-shaped,
with the proximal and distal edges parallel; the lateral thirds of the proximal and distal
borders are slightly produced. The IBr2 (axillaries) are very short, nearly or quite
three times as broad as long, rhombic in shape with concave sides and truncated lateral
angles, the lateral edges being about as long as those of the IBr,. The lateral edges and
all but the median portion of the proximal edge are very slightly produced. The
synarthrial tubercles are low and broad, scarcely evident. The contour of the proximal
portion of the animal is broadly rounded, as in 6. septentrionalis.

The 26-28 arms are 125 mm. long and have a smooth dorsal profile. The IIBr
series are 4(3+4) and the IIIBr series are 2, internally developed. The dorsal portion
of the basal segments of PD is visible between the IIBr series.

In another specimen from Siboga station 254 the IIIBr series are 2, internally
developed except for one which is situated by the side of an internal IIIBr series. In a
specimen with 28 arms eight of the IIBr series are 4(3+4) and two are 2; the cirri are
from 25 to 34 mm. long with 20-23 segments. The three other specimens are small
with 17, 19, and 20 arms.

The specimen from the Danish Expedition to the Kei Islands station 8 has 28
arms 150 mm. long. Three postradial series are regular with 6 arms each, there being
two IIBr 4(3 + 4) series and two internally developed IIIBr 2 series. One postradial
series has 7 arms, there being three IIBr 2 series. The IBr axillary is followed by two
ossicles side by side, but these bear a single very broad ossicle with two distal angles
which bears 3 arms side by side.

843803 — 50 1»

258 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The specimen from the Danish Expedition to the Kci Islands station 12 has 26
arms 130 mm. long. Two of the IIBr series are 2. There are six IIIBr 2 series, all
internally developed. The longest cirri are 30-35 mm. in length with 24-27 segments.

The specimen from the Danish Expedition to the Kei Islands station 28 has 25
arms about 120 mm. long. The centrodorsal is thick-discoidal, about twice as broad at
the base as high. The cirrus sockets are arranged in 10 columns of 3, in two cases of
2, each. The columns are closely crowded in the interradial areas, but in the midradial
lines are separated by a narrowly V-shaped deep cleft with an irregular and rugose
bottom which at the margin of the centrodorsal is usually about as broad as half the
width of the adjacent cirrus sockets. The peripheral cirri are all lost. The nine IIBr
series present are all 4(3+4). The six IIIBr series are all 2, and all are internally
developed.

The specimen from the Danish Expedition to the Kei Islands station 45 has 30
arms 120 mm. long. There are ten IIIBr 2 series, all internally developed.

The specimen from the Danish Expedition to the Kei Islands station 49 has 24
arms 140 mm. long. The longest cirri are from 32 to 35 mm. long with 26-27 segments.

The specimen from the Danish Expedition to the Kei Islands station 59 is small
with 26 arms 105 mm. long.

The specimen from the Danish Expedition to the Kei Islands station 62 has
23 arms 145 mm. long; of the IIBr series six are 2, three are 4(3+4), and one is 3; of the
IIIBr series two, both internally developed, are 2, and one, externally developed by the
side of one of the others, is 4(3+4). The longest cirri are 43-47 mm. long with 29-31
segments.

The largest specimen from Siboga station 297 has 20 arms 110 mm. long; there are
no IIIBr series; the cirri are 30 mm. long with 22—23 segments. Another has 21 arms.
The third has 18 arms about 90 mm, long.

The specimen from the Bali Sea has 26 arms about 150 mm. long. The cirri are
30-38 mm. long and are composed of 20-22 segments.

Localities. — Albatross station 5325; off northern Luzon; Hermanos Island (N.)
bearing N. 86° E., 6.75 miles distant (lat. 18°34'15" N., long. 122°01'00" E.); 409
meters; bottom temperature 11.77° C.; green mud; November 12, 1908 [A. H. Clark,
1911] (I.U.S.N.M., 27503).

Twenty-five miles east by south from Zamboanga, Mindanao; 292-365 meters;
hard bottom; Dr. Th. Mortensen, March 3, 1914 (3, U.S.N.M., E. 3237; C. M.).

Albatross station 5617; off Ternate; Ternate (S. E.) bearing S. 45° W., 7 miles
distant (lat. 0°49'30" N., long. 127°25'30" E.); 239 meters; November 27, 1909
(1, U.S.N.M., 36013).

Malay Archipelago; 55 meters; Investigator [A. H. Clark, 1909, 1911, 1912, 1916,
1918; Gislen, 1934] (1, I. M.).

Menado Bay, northern Celebes (lat. l°3l' N., long. 124°47' E.); 457 meters;
Captain Christiansen, Great Northern Telegraph Company, March 12, 1913 (3, C. M.).

Siboga station 254; west side of Taam Island (lat. 5°40' S., long. 132°26' E.);
310 meters; fine gray mud; December 10, 1899 [A. H. Clark, 1912, 1916, 1918; Gislen,
1934] (5, U.S.N.M., E. 471; Amsterdam Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 8; about 300
meters; mud; May 5, 1922 (1, U.S.N.M., E. 3199).

A MONOGRAPH OF THE EXISTING CRINOIDS 259

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 12; 320 meters;
sand; April 9, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 28; 400 meters;
mud; April 17, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 45; 270 meters;
sand; May 1, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 49; 245 meters;
sand; May 3, 1922 (1, C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 59; 385 meters;
coral; May 12, 1922 (1, U.S.N.M., E. 3154).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 62; 290 meters;
sand and shells; May 15, 1922 (1, C.M.).

Siboga station 297; Timor Sea (lat. 10°39' S., long. 123°40' E.); 520 meters; soft
gray mud with a brown upper layer ; January 27, 1900 [A. H. Clark, 1918] (3, U.S.N.M.,
E. 478; Amsterdam Mus.).

Bah' Sea (lat. 7°35' S., long. 114°42' E.); about 200 meters; Dr. Th. Mortensen's
South Africa-Java Expedition 1929-30; April 10, 1929 [A. H. Clark, 1933] (1, Buiten-
zorg Mus.) .

Geographical range. — From northern Luzon southward to the Kei Islands and
Timor and westward to Java.

Bathymetrical range. — From 55 to 520 meters; there is a possibility of error in the
first figure; the next shallowest depth recorded is about 200 meters.

Thermal range. — One record, 11.77° C.

History. — Pachylometra investigator-is was first described in 1909 from a specimen
dredged by the Royal Indian Marine Survey Steamer Investigator in the Malay Archi-
pelago in 30 fathoms. In 1911 it was again described under the name of Pachylometra
luna on the basis of a specimen from Albatross station 5325. In 1912 I described
Pachylometra helius from a specimen from Siboga station 254. Later in the same year
in my memoir on the crinoids of the Indian Ocean I redescribed and figured Pachylo-
metra investigatoris and listed P. luna giving the original reference and the range. On
the establishment of the genus Crossometra in 1916 Pachylometra investigatoris was
selected as the genotype, and P. helius was included in it. In my memoir on the
unstalked crinoids of the Siboga Expedition published in 1918 Crossometra helius was
redescribed and figured, and three specimens of C. investigatoris were recorded from
station 297 with notes; Pachylometra luna was included as a synonym under C. inves-
tigatoris. In 1933 I recorded and gave notes on a specimen of Crossometra helius from
the Bali Sea.

In 1934 Prof. Torsten Gislen recognized a special type of crinoid arm branching
which he called the Crossometra septentrionalis type, including in it Crossometra helius
and C. investigatoris.

GLYPTOMETRA MACILENTA (A. H. Clark)

PLATE 26, FIGURES 7^81
[See also vol. 1, pt. 2, figs. 533, 534, p. 287, 670, p. 335.]

Pachylometra macilenta A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 81 (description;
10°47'45" N., 72°40'20" E.; 705 fathoms), p. 149 (compared with P. invenusta); Crinoids of the
Indian Ocean, 1912, p. 222 (synonymy; detailed description; locality), fig. 41, p. 223.

260 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Perissometra macilenta A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed) ;
Unstalked crinoids of the Siboga-Exped., 1918, p. 178 (in key; range), p. 181 (references); Journ.
Linn. Soc. (Zool.), vol 36, No. 249, April 1919, p. 658 (south of Timorlaut; 500 fathoms; notes). —
GiSLfiN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 21.

Perissometra occidentalis A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 635
(listed), p. 655 (120 miles off the Seychelles, 800 fathoms; description), pi. 42, fig. 10; John Murray
Exped., 1933-34, Sci. Reports, vol. 4, No. 4, Crinoids, 1936, 1937, p. 101 (range), p. 104.

Diagnostic features. — The cirri, which are arranged in 10 columns on the centro-
dorsal, are comparatively long and slender, 25-36 mm. long with 15-22 segments of
which the earlier are from one-third to half again as long as broad and the distal are
about as long as broad; the 13-15 arms are 130-170 mm. long; and the division series
and arm bases are rugose.

Description. — The centrodorsal is a short truncated cone, moderately large, with
the bare dorsal pole flat and 2.5 mm. in diameter. The cirrus sockets are arranged in
10 columns of usually 2 each, the columns of adjacent radial areas closely crowded
and more or less alternating, the two within the same radial area usually slightly sepa-
rated proximally.

The cirri are XX, 21-22, from 25 to 36 mm. long, comparatively long and slender.
The first segment is very short, the second is twice as broad as long, the third is about
as long as broad, and those following gradually increase in length to the sixth, which
is about half again as long as broad. The next two or three segments are similar, those
succeeding very gradually decreasing in length so that the segments in the terminal
third of the cirri are about as long as broad. The antepenultimate segment is about
one-third again as long as broad, and the penultimate segment is half again as long as
broad and is slightly less in diameter than the preceding. The opposing spine is very
small, though prominent; it is terminally situated and directed obliquely forward.
The terminal claw is about as long as the penultimate segment, stout basally but
becoming slender in the distal half, and is moderately curved. The cirri are moderately
compressed in the distal two-thirds. The two or three segments before the penultimate
have slight traces of terminal dorsal tubercles.

The ends of the basal rays are visible as large rhombic tubercles in the angles of
the calyx.

The radials are visible only as a large transversely oval tubercle between the
centrodorsal and the IBr^ The IB^ are very short, arcuate, in close lateral apposition;
the proximal border is more or less crenulate and bears a large and rather high trans-
versely oval median tubercle. The IBr2 (axillaries) are rhombic, very short, somewhat
over twice as broad as long, with the edges somewhat cremdate and somewhat pro-
duced, the proximal imbricating more or less over the distal border of the IBrij the
lateral edges are very short and are in close apposition. The IBr2 bear a rather high
rounded median tubercle. The IIBr series are 4(3+4), in close lateral apposition and
sharply flattened, with the lateral borders somewhat everted. The distal edge of the
IIBr, is somewhat everted, and the proximal edge of the IIBr2 is more strongly everted,
the latter imbricating over the former except in the median line. The IIBr, usually
bears a strong rounded median tubercle like that on the two components of the IBr
series.

The 13 arms in the type specimen are 170 mm. long, elongated and comparatively
slender, resembling those of Pachylometra robusta.

A MONOGRAPH OF THE EXISTING CRINOIDS 261

The pinnules in general resemble those of Pachylometra robusta; those in the
proximal portion of the arm are strongly carinate.

The disk is covered with a pavement of very small plates. Side and covering plates
are well developed along the pinnule ambulacra.

The color in alcohol is white.

Notes. — The specimen from south of Timorlaut has 14 arms about 150 mm. long.

In 1929 I described Perissometra occidentalis as follows:

The centrodorsal is large, truncated conical, with the cirrus sockets arranged hi
10 closely crowded columns of usually 3 each.

The cirri are about XXV, 15-18, moderately stout, the longest from 30 to 35 mm. in
length. The first segment is very short, the second is longer, the third is about twice as
broad as long, the fourth is nearly as long as broad, and the fifth is about one-third
again as long as broad on the longest peripheral cirri, and very slightly longer than
broad on the other cirri. The following segments decrease in length so that the last
seven or eight before the penultimate are about as long as broad. The penultimate
segment is narrower than those preceding, and hi lateral view is from one-third to one-
half again as long as broad. From the fifth onward the segments in lateral view have
slightly diverging ventral and dorsal edges, and their distal ends slightly overlap the
bases of the segments following. On the dorsal side the distal end of the segments may
be thickened so as to project considerably beyond the base of the succeeding segments,
giving the dorsal profile of the outer portion of the cirri a low and roundedly serrate
appearance. The opposing spine, which arises from the conspicuous white terminal
band on the penultimate segment, is transversely broadened, with the crest chisel-shaped
or strongly bilobate.

The ends of the basal rays are visible as prominent rhombic tubercles in the
interradial angles.

The radials are entirely concealed by the centrodorsal. The IBr! are very narrow
and bandlike, usually quite concealed by the centrodorsal except for a rounded median
tubercle and the very narrow and irregular lateral portions, which extend diagonally
outward, meeting those of the adjacent IBrj above the ends of the basal rays. The
borders of these lateral portions are sinuate, and the distal angle is usually produced
inwardly in the form of a conspicuous tooth which fits into a corresponding cavity be-
neath the lateral angle of the axillary. The IBr2 (axillaries) are broadly rhombic with
the lateral angles slightly truncated forming short sides, which are about as long as the
length of the lateral portions of the IBr,. The median portion of the axillaries is
elevated, rising regularly into a very broadly rounded tubercle with the maximum
height in about the proximal third. The proximal border of the axillary, except in
the median line, is produced into a flangelike extension with a sinuous and more or less
irregular edge, the irregularities fitting into corresponding irregularities in the adjacent
border of the IBiv There are five IIBr series present, four of these being 4(3+4) and
one being 2. The division series are smooth dorsally and rise evenly to a very broadly
convex central portion. They are closely appressed against then1 neighbors. The
IIBrj are very short and their inner portion is extended distally and is terminated by a
short side at right angles to the lateral edge, which is usually more or less produced
inwardly hi the form of a tooth fitting into a notch in the IIBr2.

262 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The 15 arms are about 130 mm. long. The first brachials are very short, five or six
times as broad as long, with the inner portion curving about and extending to beyond
the middle of the second brachial where it is bounded by a line at right angles to the
lateral edge. The inner corner of this distal border is extended in the form of a more
or less pronounced tooth which fits deeply into a corresponding excavation in the side
of the second brachials. The second brachials are about twice as long as the first.
They are irregularly half-moon shaped, as a result of the overlapping of their proximal
portion by the distal extensions of the first brachials, but their inner angles are some-
what abruptly produced over the ends of these processes, coming into lateral contact.
The lateral borders of the first two brachials are slightly turned outward. On arms aris-
ing directly from a IBr axillary the first syzygial pair (composed of brachials 3+4) is
about three times as broad as long, oblong, but with the proximal and distal borders
broadly sinuous. The next seven brachials are wedge-shaped, about three times as
broad as the median length, and those following become triangular, about as long as
broad, and wedge-shaped again in the outer portion of the arms.

PI is 12 mm. long and is composed of 30 segments. It is rather stout at the base,
but tapers evenly and rather rapidly so that the distal fourth is slender and delicate.
The first segment is large, much broader than long, and is extended distally both at the
dorsal and ventral angles so as to overlap for some distance the proximal angles of
the second. The second segment is scarcely two-thirds as broad as the first, not quite
twice as broad as long; its distal dorsal and ventral angles are extended slightly for-
ward, and are more or less blunted or rounded off. The third segment is similar, but
the distal processes are shorter and more broadly rounded. The following segments
have the outer portion of the distal border curved toward the pinnule tip. The seg-
ments increase in length very slowly, not becoming as long as broad until very near the
pinnule tip. All the segments, except those at the extreme end of the pinnule, are
somewhat produced dorsally and sharply carinate.

P2 is 13 mm. long, stouter than PI and tapering more gradually so as to lack the
delicate tip. It is composed of 25 segments which become as long as broad on the
twelfth and somewhat longer than broad terminally.

P3 is 13 mm. long with 20 segments, tapering still more gradually than ?2. The
segments become as long as broad on about the twelfth, and slightly longer than broad
distally.

On the genital pinnules the third, fourth, and fifth segments are somewhat enlarged
and broadened to protect the gonads.

The distal pinnules are 13 mm. long with about 16 segments, most of which are
from half again to twice as long as broad.

Examination of enlarged photographs of the type specimens of macilenta and
occidentalis fails to reveal any significant character by means of which they may be
distinguished.

Localities. — South of Timorlaut (lat. 11° S., long 131°30' E.; 914 meters; cable
repair ship Patrol, Eastern and Associated Telegraph Company [A. H. Clark, 1929]
(1,B. M.).

Laccadive Islands (lat. 10°47'45" N., long. 72°40'20" E.); 1,288 meters; Investi-
gator [A. H. Clark, 1909, 1912, 1916, 1918; Gislen, 1934] (1, 1. M.).

A MONOGRAPH OF THE EXISTING CRINOIDS 263

One hundred and twenty miles off the Seychelles; 1,462 meters; cable repair
ship Lady Denison-Pender, Eastern and Associated Telegraph Co. [A. H. Clark, 1929]
(1, B. M.).

History. — This species was first described under the name of Pachylometra
macilenta in 1909 from a single specimen dredged among the Laccadive Islands by
the Royal Indian Marine Survey steamer Investigator. It was redescribed and figured
in my memoir on the crinoids of the Indian Ocean published in 1912. On the establish-
ment of the genus Perissometra in 1916 macilenta was transferred to it, and in my
memoir on the unstalked crinoids of the Siboga Expedition published in 1918 macilenta
was included in the key to the species of Perissometra and the synonymy and range
were given. In 1929 I recorded and gave notes on another specimen that had been
brought up on a cable south of Timorlaut by the cable repair ship Patrol of the Eastern
and Associated Telegraph Company. In the same paper I described and figured
under the name Perissometra occidentalis, sp. nov., a specimen from 120 miles off
the Seychelles found on a cable by the cable repair ship Lady Denison-Pender of the
same company.

In 1934 Prof. Torsten Gislen selected Perissometra macilenta as representing a
special type of crinoid arm division including also Pachylometra distincta and P.
inaequalis.

GLYPTOMETRA ANGUSTICALYX (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 275, p. 260, 490, p. 367; pt. 2, pi. 3, figs. 984, 985, pi. 14, fig. 1055, pi. 26, fig.

1159, pi. 42, figs. 1270-1272.]

Antedon, sp. P. H. CARPENTER, Pop. Sci. Rev., vol. 4, No. 15, 1880, p. 194, pi. 6, fig. 12 (plated disk).

Antedon angusticalyx VON GRAFF, Challenger Reports, Zool., vol. 10, pt. 27, 1884, pp. 17, 70 (Challenger
sta. 214; myzostomes; nomen nudum). — P. H. CARPENTER, Challenger Reports, Zool., vol. 11, pt.
32, 1884, pp. 57, 83, 84, 93, 109, 110, 113, 128, 135, pi. 54, fig. 5, pi. 55, fig. 6.— VON GRAFF, Chal-
lenger Reports, Narrative, vol. 1, pt. 1, 1885, p. 316 (myzostomes). — P. H. CARPENTER, Chal-
lenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 242 (description; Challenger station 214), pi. 2,
figs. 4, a-d, pi. 50, figs. 1, 2, text fig. 5, B, p. 246. — SPRINGER, Mem. Mus. Comp. Zool., vol. 25,
No. 1, 1901, p. 45 (tegmen compared with that of Holocrinus). — MINCKERT, Arch. Naturg.,
Jahrg. 71, 1905, vol. 1, Heft 1, p. 224 (syzygies; regeneration). — HAMANN, Bronn's Klassen
und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1582 (listed). — A. H. CLARK, Crinoids
of the Indian Ocean, 1912, p. 35 (identity).

Charitomelra angusticalyx A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed);
Smithsonian Misc. Coll., vol. 52, pt. 2, 1908, p. 227 (compared with Ch. smithi).

Pachylometra angusticalyx A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed);
Proc. U. S. Nat. Mus., vol. 36, 1909, p. 407 (compared with P. levigata); vol. 37, 1909, p. 34 (same
constriction of proximal portion occurs in Ptilometra splendida) ; Crinoids of the Indian Ocean,
1912, p. 35 (identity), p. 216 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913,
p. 47 (published reference to specimens in the B. M.; Challenger station 214).- — GISLEN, Zool.
Bidrag Uppsala, vol. 9, 1924, p. 280; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11,
1934, pp. 21, 22.

Perissometra angusticalyx A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607
(listed) ; Unstalked crinoids of the Siboga-Exped., 1918, p. 176 (in key; range), p. 178 (references). —
GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, No. 35 (notes).

Diagnostic features. — The proximal portion of the animal is constricted, the sides
of the IBr series being parallel or nearly so, the IIBr series somewhat abruptly turned
outward; the cirri have 18-23 segments of which all but the basal are longer than

264 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

broad; the 14-20 arms are 75 mm. long; and the division series and arm bases are
smooth.

Description. — The centrodorsal is a truncated hemisphere, marked by indistinct
interradial ridges which are produced upward into rather prominent processes between
the radials. The cirrus sockets (according to the figure) are arranged hi 10 columns of
2 or 3 each, the columns being in close contact interradially but separated by a broad
shallow groove in the midradial line.

The cirri are XX-XXV, 18-23. According to the figure the segments beyond the
basal are all longer than broad, most of them about half again as long as broad. There
is no opposing spine.

The radials are concealed. The IBri are quite short, especially in the median line,
and are barely in contact above the angles of the centrodorsal. According to the figure
they form a deeply U-shaped rather narrow band about the broadly rounded posterior
projection of the axillary, which sometimes almost reaches the ceutrodorsal. The
IBr2 (axillaries) are somewhat broader than long, deeply shield-shaped with the distal
angle very obtuse, scarcely rising higher than the anterolateral angles, and a long
broadly rounded posterior projection. The IIBr series are 4(3+4) and, together with
a few of the proximal brachials, are in close lateral apposition and sharply flattened
laterally. The first two elements of the IIBr series are somewhat tubercular.

The 14-20 arms are 75 mm. long and are composed of over 100 brachials of which
the lowest are nearly oblong and their successors triangular, broader than long, gradu-
ally becoming longer and more wedge-shaped.

In arms arising from a IBr axillary the first sj^zygy is between brachials 3+4 and
the next is from between brachials 12 + 13 to between brachials 16+17. In arms
arising from IIBr axillary the first syzygy is usually between brachials 1+2 and the
next from between brachials 8+9 to between brachials 26+27, usually about brachials
13 + 14 or 15 + 16. The distal intersyzygial interval is from 5 to 13, usually 7 or 8,
oblique muscular articulations.

PD is about 9 mm. long with about 30 short carinate segments the lowest of which,
though thick, are not especially broad. The next two or three pinnules are of about
the same length with relatively longer distal segments, and the lower ones somewhat
flatter. The following pinnules are a little shorter, with the first two segments smaller
than in the proximal pinnules; but the third segment and from two to four of its suc-
cessors are broad and flattened with the outer edges much produced toward the ventral
side. Traces of this expansion may be visible as far as the twenty-fifth brachial, after
which the segments become elongated and the pinnules more slender.

The disk is 7 mm. in diameter, much incised and completely plated, as are also
the brachial ambulacra and the mterarticular spaces. The gonads are covered by closely
set plates in which sacculi are embedded. These are small and inconspicuous on the
pinnule ambulacra, which have well-defined side plates.

The color in alcohol is light whitish brown.

Notes. — Carpenter's specimens in the British Museum have been examined by
Professor Gislen and by myself, but neither of us had anything to add to the original
description and figures.

Locality. — Challenger station 214; off the Meangis Islands (lat. 4°33' N., long.
127°06' E.); 914 meters; bottom temperature 5.44° C.; blue mud; February 10, 1875

A MONOGRAPH OF THE EXISTING CRINOIDS 265

[P. H. Carpenter, 1880, 1884, 1888; von Graff, 1884, 1885; Springer, 1901; Minckert,
1905; Hamann, 1907; A. H. Clark, 1907, 1908, 1909, 1912, 1913, 1916, 1918; Gislen,
1924, 1928, 1934] (5, B.M.).

History. — Dr. P. H. Carpenter in 1880 published a figure of a plated disk of a
comatulid identified only as Antedon, sp.

In 1884 Prof. Ludwig von Graff described some myzostomcs from Antedon angus-
ticalyx from Challenger station 214. The name, which had been given him by Dr.
P. H. Carpenter, was a nomen nudum.

In his report on the stalked crinoids of the Challenger Expedition Dr. Carpenter
gave a "specific formula" for this species, which is the equivalent of a description. He
described the swollen genital pinnules in detail, noting that they receive no branches
from the brachial food grooves and lack the ambulacra! epithelium, nerves, and blood
vessels, while the water vessels are simple tubes like the integumentary water vessels
of the Molpadiidae without lateral extensions, since the tentacles are absent. He
remarked that the fertile intrapinnular portions of the gonads are short, thick, and
rounded, and that the sacculi occupy little pits in the large plates that cover the ovarian
pinnules, and also in the substratum of the small later segments of the pinnules. He
said that the ambulacra crossing plated disks are generally marked by an irregular
row of transversely oblong plates, as in this species. He gave a figure of an ovarian
pinnule and republishcd the figure of a plated disk published hi 1880, identifying it as
Antedon angusticalyx.

Professor von Graff again mentioned the myzostomes of Antedon angusticalyx
in 1885.

In the Challenger report on the comatulids published in 1888 Dr. Carpenter de-
scribed Antedon angusticalyx in detail and figured it. Wilhelm Minckert discussed the
distribution of the syzygies in this species in 1905.

In my first revision of the old genus Antedon published in 1907 angusticalyx was
assigned to the new genus Charitometra, and as Charitometra angusticalyx it was com-
pared with the new species Charitometra smithi in 1908. In 1909 this species was
transferred to the new genus Pachylometra, and Pachylometra angusticalyx was com-
pared with the new species P. levigata. In the same year the constriction of the proxi-
mal portion of this species was compared with a parallel constriction of the proximal
portion of Ptilometra splendida.

In my memoir on the crinoids of the Indian Ocean published in 1912 Pachylometra
angusticalyx was listed and the synonymy and range were given. In 1913 I noted
that I had examined five small specimens from Challenger station 214, the type material,
in the British Museum.

In 1916 angusticalyx was transferred to the new genus Perissometra and listed as
Perissometra angusticalyx, and hi my memoir on the unstalked crinoids of the Siboga
Expedition Perissometra angusticalyx was included in a key to the species of that
genus, and the synonymy and range were given.

Prof. Torsten Gislen in 1924 noted that Carpenter hi 1884 had pointed out that
two representatives of the family Charitometridae, later identified as Poecilometra
acoela and Pachylometra angusticalyx, sometimes lack the ambulacral grooves on as
many as 20 pairs of proximal pinnules. In 1928 he noted that he had examined the
Challenger specimens of Perissometra angusticalyx and that the species should be re-

266 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ferred to the genus Crossometra; he rem^ked upon the unsatisfactory nature of Perisso-
metra and Crossometra as understood by me. In 1934 he discussed what he termed the
Pachylometra angusticalyx type of arm branching.

GLYPTOMETRA SPAKKSI (John)

Pachylometra, n. sp., A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 51 (lat. 14°20' N., long.
52°30' E., 1,200 fathoms; Electro); Crinoids of the Indian Ocean, 1912, p. 224 (same) ; Smithsonian
Misc. Coll., vol. 61, No. 15, 1913, p. 70 (same); John Murray Exped. 1933-34, Sci. Rep., vol. 4,
No. 1, 1936 (Jan. 1, 1937), pp. 101 (same), 104, 105.

Perissometra sparksi JOHN, Ann. Mag. Nat. Hist., ser. 10, vol. 20, p. 161, August 1937.

Diagnostic features . — The cirri, which are heavy and strongly curved, are arranged
in 10 columns on the centrodorsal ; they are composed of 14-21 segments of which all
but the basal are longer than broad; there are 14 arms in the type specimen; and the
division series and arm bases are moderately broad and smooth.

Description. — The centrodorsal is a thick disk with a flattened dorsal pole and
strongly produced interradial angles. The cirrus sockets are arranged in 10 columns of
3 each, 2 columns in each radial area. The two columns in one radial area touch at the
dorsal pole but diverge toward the periphery so as to run to the interradial angles. The
two adjacent columns of contiguous radial areas are in close contact.

The cirri are XXXI, 14-21, heavy and strongly curved. The first three segments
are broader than long, the first more so than the second, and the second than the third.
The fourth is as long as broad. The remainder are longer than broad, the sixth to about
the tenth being more than half again as long as broad; those beyond decrease very
slightly in length. The articulations are only a little swollen. There is no trace of
dorsal spines. The distal half to third of the penultimate segment, the opposing spine,
and the terminal claw are sharply marked off through being of a lighter color than the
rest of the cirrus. The opposing spine is low, or very low. The terminal claw varies
from stout, moderately curved, and shorter than the penultimate segment to small and
less than half as long as the penultimate segment.

The ends of the basal rays and the radials are concealed. The IBrt are short and
roughly crescentic. They are longest (1) in the midradial line where they are produced
backward between the interradial corners of the centrodorsal, either narrowly to a point,
or more broadly not to a point, but evenly; and (2) laterally where they are produced
anteriorly alongside the IBr2, which they therefore appear to grip. The proximal edge
is variable and uneven. The distal edge is produced into a rounded angle in the midline
incising the posterior angle of the IBr2. The IBr2 (axillaries) are about three times as
broad as the greatest length, which is along the median line. The proximal and distal
edges of the middle two-thirds of the ossicle are convex, the former more strongly so
than the latter except that it is incised in the midline by the IBrt. Each lateral sixth
beyond the projections of the lateral edges of the IBrj is marked off by a constriction,
and each is square and incises the proximal exterior corner of the IIBri beyond it. The
distal median portion of the IBri is very slightly elevated to form a low wide inconspic-
uous mound with the proximal median portion of the IBr2, which is similarly raised.
The IIBrj has the shape of a thick shallow cup, the median two-thirds of the distal half
being deeply excavated. The proximal edge of the median two-thirds of the IIBr2 is
produced backward to occupy the concavity in the IIBr^ its distal edge is faintly con-
cave. The ossicles of the division series are free from tubercles. Their dorsal surfaces

A MONOGRAPH OF THE EXISTING CRINOIDS 267

are convex except for flat strips along the lateral edges. The lateral edges are straight
and the sides are flattened. There are four IIBr series, one on each of four rays; three
of these are 4(3+4) and one is 2.

There were originally 14 arms. Only 5 arms, aU 3 of one ray and two, which have
been regenerated, of another remain nearly complete. It is impossible to say how long
the arms were in life. An incomplete arm of 36 brachials measures 40 mm. The first
two brachials of an arm arising directly from a IBr axillary are shaped like the IIBr]
and IIBr2 described above. Those of an arm arising from a IIBr axillary are roughly
rectangular except that the distal interior corner of each is produced. They are nearly
or quite three times as broad as long. The first syzygial pair (composed of brachials
3+4) is rectangular and may be twice as broad as long. The brachials immediately
following are slightly wedge-shaped, more than half again as broad as long; those farther
out are nearly triangular and as long as broad. The brachials are smooth. There are
detached pieces of the outer arm which show that the outer brachials are of the shape of
those just described, with their distal edges slightly produced.

In the one remaining arm of those springing directly from a IBr axillary syzygies
occur between brachials 3+4, 7+8, and 15+16, and thereafter at intervals of 4 or 5
muscular articulations (as far as the thirty-second brachial, at which the arm is broken
off). In an arm springing from a IIBr axillary, complete to the thirty-eight brachial,
the syzygies occur between brachials 3 + 4, 11 + 12, 19+20, 30 + 31, and 37+38. In
fragments of the more distal parts of the arm syzygies occur at intervals of from 4 to 8
muscular articulations.

No PD remains complete. The least damaged is of 24 segments and is 8 mm. long.
The first segment is large, more than twice as broad as long, and flattened exteriorly.
On the following ten segments there is a gradual decrease in width; the eleventh is
nearly as long as broad. The more distal segments are small and even, nearly as long
as broad. All the segments, but particularly the larger proximal segments, are carinate
dorsally; the carination of each is produced a little toward the next. Pt is 14 mm. long,
and is composed of 34 segments of which the first six or seven are heavy, nearly twice
as broad as long, but gradually decreasing in size. The other segments are small, very
gradually decreasing in size, all slightly broader than long. All the segments are faintly
carinate. There is not such a contrast between heavy basal and lighter distal segments
as there is in PD. P2 is about 9 mm. long, of 17 segments. The first eight segments
are large, wider than long, and faintly carinate dorsally. The remainder are smaller,
rounded, longer than broad, and gradually increasing hi length. The genital pinnules
are about 8 mm. long with 13-15 segments. The first two segments are short, and
the third and fourth are larger, the largest in the pinnule, considerably broader than
long. The distal dorsal end of each, but particularly of the fourth, is raised and pro-
duced a little. The fifth segment is narrower, roughly as long as broad. There is an
abrupt transition between the first five and the following segments; the sixth and
following are regular, laterally compressed, narrow, longer than broad, and slowly
increase in length so that the distal segments are nearly twice as long as broad. The
more distal pinnules are about 10 mm. long with 15-17 segments of which all but the
first two are similar, rectangular, slightly longer than broad, and slowly decreasing
in size.

268 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The pinnule ambulacra are heavily plated.

Remarks. — Mr. John said that, unlike most of the other species of the genus, the
IBrj and IBr2 of P. sparksi are not raised into prominences big enough to be called
"tubercles" or "carinations." Perissometra crassa from the Kei Islands has no promi-
nences, and those of P. occidentalis from near the Seychelles are low. It is perhaps
the latter species that P. sparksi most nearly resembles. The shapes of the ossicles
of the division series are similar in both. But there are many differences, and the
two species may be separated by the cirri alone — those of P. sparksi are composed
of longer segments and are longer and smoother than those of P. occidentalis.

Locality.— Northwest of Sokotra (lat. 14°20' N., long. 52°30' E.); 2,194 meters;
Capt. V. F. Sparks, cable repair ship Electra, July 1909 [A. H. Clark, 1911, 1912, 1913,
1937; John, 1937] (1, B. M.).

History. — During a visit to the British Museum in 1910 I examined the type
specimen of this species, but did not have time to draw up a description of it. I men-
tioned it as Pachylometra, n. sp., in 1911, 1912, 1913, and 1937. It was formally described
by D. Dilwyn John in 1937.

GLYPTOMETRA SCLATERI (Bell)

Antedon sclateri BELL, Marine investigations in South Africa, vol. 4, pt. 4, 1905, p. 140 (description;
East London, NW. 1/2 N., 18 miles; 250-300 fathoms), pi. 3, figs. 1-3. — A. H. CLARK, Proc.
Biol. Soc. Washington, vol. 21, 1908, p. 126 (belongs to Charitometra, near inaequalis) ; Proc.
U. S. Nat. Mus., vol. 34, 1908, pp. 437, 493 (described in the Savignyi group; really belongs in
the Granulifera group and is very close to inaequalis) ; vol. 40, 1911, p. 5 (identity); Crinoids
of the Indian Ocean, 1912, p. 40 (identity).

Charitometra sclateri A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (belongs in
Charitometra, near inaequalis).

Pachylometra sclateri A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 21 (listed); Proc.
U. S. Nat. Mus., vol. 40, 1911, p. 5 (identity), p. 8 (southeast coast of Africa), p. 38 (synonymy;
locality); Crinoids of the Indian Ocean, 1912, p. 40 (identity), p. 216 (synonymy; locality);
Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 48 (published reference to specimens in the B. M. ;
stations 12676, 12711, 12792, 12885/6; no loc.; characters of the centrodorsal) ; Die Crinoiden
der Antarktis, 1915, p. 164 (represents the family Charitometridae in South Africa; range);
Unstalked crinoids of the Siboga-Exped., 1918, p. 184 (in key; range), p. 185 (references). —
H. L. CLARK, Ann. South African Mus., vol. 13, pt. 7, No. 12, 1923, p. 234 (new localities; charac-
ters of 10-armed young). — GISL^N, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8, No. 38 (notes). —
A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936, pp. 101 (range),
105.— GiSLfiN, Kungl. Svenska Vet. Akad. Handl., ser. 3, vol. 17, No. 2, Oct. 3, 1938, p. 4, p. 18
(localities; notes), figs. 16, 17, p. 19, pi. 2, fig. 7.

Diagnostic features.- — The cirri are arranged in 10 columns on the centrodorsal;
they are 18-20 mm. long with 16 segments of which all but the basal are longer than
broad; there are 11-17 arms; and the division series and arm bases are smooth and very
broad.

Description. — Bell's original description is as follows:

This somewhat variable species appears to belong to Division II of Carpenter's A. savignyi
group (see Chall. Report Comat., p. 252). There are not as many as 20 joints in the cirri, and may
be no more than 15, the distichal pinnule is small, and there are no lateral processes to the pinnules;
there are 20 arms or less, but always more than 10.

The cirri vary not only in the number of joints, but in the length of them, so that what appear
to be fully developed cirri may be less than 15 or more than 30 mm. long; the increase in length is
due rather to the increased length of the joints than to an increase in number.

A MONOGRAPH OF THE EXISTING CRINOIDS 269

The figure, drawn by Mr. C. Berjeau, who drew many of the excellent figures
for the Challenger report on the comatulids (plates 1-5, and in cooperation with
Highley plates 6-37, 63, 66, and 70) and therefore may be regarded as reliable, shows
a species with the proximal profile broadly rounded as in G. septentrionalis.

According to Gisl6n the cirri are arranged in 10 columns on the centrodorsal.
The figure shows them to have about 16 segments and Dr. Hubert Lyman Clark says
they are 18-20 mm. long. All but the basal segments are longer than broad, the longest
from half again to twice as long as broad, the distal from slightly longer than broad to
nearly half again as long as broad. Berjeau shows a slight opposing spine which Gisle"n
says is spiny.

The radials are concealed, and the IBri may be more or less concealed. In the
figure six IIBr series are shown of which five are 4(3+4) and one is 2. The division
series and lower brachials are apparently evenly rounded dorsally and not rugose.

There are 11-17 arms.

The first syzygy appears to be between brachials 1+2 and the next from between
brachials 11 + 12 to between brachials 13 + 14.

PI is shown as slender, tapering evenly from the base to the tip, flexible, with 31
segments of which the earlier are somewhat broader than long and the distal are longer
than broad. P2 is similar. P3 and P4 are of about the same length but have only 18
segments of which the second-fifth or -sixth are considerably broadened, the pinnule
beyond these tapering graually to a slender tip.

Notes. — I examined 28 specimens of this species in the British Museum and noted
that the centrodorsal bears radial furrows, which would indicate that the cirri are
arranged in 10 columns, 2 in each radial area; but in the Siboga report I ranged this
species with those having the cirri in 15 columns. Gisl6n in 1928 wrote that in sclateri
the cirri are hi 10 columns and called attention to the fact that I had placed it with
species having the cirri in 15 columns. The arms in the specimens examined by him
varied from 11 to 17.

Localities. — Pieter Faure Nos. 12676 and 12711; East London bearing N. W.,
1/2 N., 18 miles distant; 457-548 meters: hard ground and broken shells [Bell, 1905:
A. H. Clark, 1908, 1909, 1911, 1912, 1913, 1915, 1918, 1936; H. L. Clark, 1923; Gislen,
1928, 1934] (12, B. M.).

Pieter Faure No. 12872; East London bearing N., 15 miles distant; 566 meters;
mud [H. L. Clark, 1923].

Pieter Faure No. 12792 [A. H. Clark, 1913] (4, B. M.).

Pieter Faure No. 12885/6 [A. H. Clark, 1913] (1, B. M.).

Pieter Faure; no locality [A. H. Clark, 1913] (11, B. M.).

Geographical range. — Known only from off East London, South Africa.

Bathymetrical range. — From 548 (?457) to 566 meters.

History. — Antedon sclateri was described by Prof. Francis Jeffrey Bell in 1905
from specimens dredged off East London, South Africa by the fisheries steamer Pieter
Faure in the course of marine investigations of the -South African coasts. Professor
Bell placed the species in Carpenter's Savir/nyi group, which included the species of
Heterometra and Craspedometra, entirely overlooking the plating of the pinnule and
brachial ambulacra.

270 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

At the time I published my first review of the genus Antedon in 1907 I had not
been able to consult Professor Bell's paper; but in 1908 I wrote that Antedon sclateri
belongs to the genus Charitometra and is near C. inaegualis. In another paper published
later in the same year I noted that Bell had referred Antedon sclateri to Carpenter's
Savignyi group whereas it is in reality a member of the Granulijera group and is very
close to Charitometra inaegualis. In my revision of the families Thalassometridae (at
that time including the Charitometridae) and Himerometridae published in 1909 I
established the new genus Pachylometra and listed sclateri under it. In my memoir
on the recent crinoids of the coasts of Africa published in 1911 I identified Antedon
sclateri as Pachylometra sclateri and gave the synonymy and locality. It was again
listed as Pachylometra sclateri in my memoir on the crinoids of the Indian Ocean pub-
lished in 1912. After examining the crinoids in the British Museum I recorded 28
specimens of Pachylometra sclateri under Pieter Faure numbers 12676 (5), 12711 (7),
12792 (4), and 12885/6 (1), and also 11 from the Pieter Faure collection without locality;
but the note on them was that the centrodorsal shows radial furrows. In my memoir
on the crinoids of the Antarctic published hi 1915 I said that Pachylometra sclateri
represents the family Charitometridae in South Africa, and gave the range. In my
memoir on the uns talked crinoids of the Siboga Expedition published in 1918 sclaMri
was included in the key to the species of Pachylometra and the synonymy and range
were given. In his memoir on the echinoderm fauna of South Africa published in
1923 Dr. Hubert Lyman Clark recorded an adult specimen from Pieter Faure number
12872 which he said had the calyx about 12 mm. in diameter and the cirri 18-20 mm.
long, and hi addition what he believed to be the 10-armed young from Pieter Faure
numbers 12884 (1) and 13227 (13), giving notes on the latter.

After studying the comatulids hi the British Museum Prof. Torsten Gislen in
1928 wrote that the centrodorsal hi Pachylometra sclateri is discoidal, the cirri are
arranged in 10 columns and are without dorsal spines, and the opposing spine is spiny
(presumably meaning sharp). The specimens he examined had 11, 14, 16, and 17 arms.
In my report on the crinoids of the John Murray Expedition to the Indian Ocean
1933-34, published in 1937 I listed Pachylometra sclateri and gave the range. In his
paper on crinoids from South Africa published in 1938 Professor Gislen gave notes on
and figured four small 10-armed specimens which he tentatively referred to Pachylo-
metra sclateri. The smaller specimens (Nos. 1-3) were from one of the stations from
which Dr. Clark's small specimens came; the largest (No. 4) had been collected by
Dr. Th. Mortensen. In the last the keel on the dorsal side of the cirrus segments is
somewhat more distinct and the lateral sculpture of the arm-bases is a little more
obvious, but the general appearance and distance of the syzygies is the same. How-
ever, he added, the specimen is still 10-armed and the ossicles of the division series
much longer (a characteristic which may of course be an indication of youth) then
in the specimen figured by Bell. In fact, he said, the genital pinnules are closely rem-
iniscent of Charitometra. Provided that it is not a young of Pachylometra sclateri it is
a new species which may probably be most correctly ranged within the 10-armed genus
Charitometra.

The small 10-armed specimens recorded by Dr. H. L. Clark and Professor Gislen
as the young of Pachylometra sclateri are in reality adults of Gislenometra perplexa of
the family Colobometridae (see Part 4b, p. 59).

A MONOGRAPH OF THE EXISTING CRINOIDS 271

GLYPTOMETRA LEVIGATA (A. H. Cl»rk

PLATE 27, FIGURES 82, 83
[See also vol. 1, pt. 2, fig, 671, p. 335.]

Pachylometra levigata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 406 (description; Albatross
station 5236) ; Crinoids of the Indian Ocean, 1912, p. 224 (synonymy; locality); Unstalked crinoids
of the Siboga-Eixped., 1918, p. 184 (in key; range), p. 185 (references).

Pachylometra laevigata GISLEN, Vid. Medd. Dansk Xat. Foren. K0bcnhavn, vol. 93, 1933, p. 482

(perhaps a species of Crinometra).

Diagnostic features. — The cirrus sockets are arranged in 15 columns on the centro-
dorsal; the cirri are 15 mm. long with 14-15 segments, all of which are longer than broad,
the longest earlier segments half again as long as broad; the 12-14 arms are 100 mm.
long; and the division series and arm bases are smooth, without ornamentation.

Description. — The centrodorsal is thick-discoidal or more or less columnar with the
flat polar area 2.5 or 3 mm. in diameter. The cirrus sockets are arranged in three col-
umns in each radial area, the two outer columns converging distally and usually meeting
beyond the middle column. The columns are usually separated by more or less de-
veloped ridges.

The cirri are XXX-XXXV, 14-15, 15 mm. long. The first two segments are
about twice as broad as long, the third is about as long as broad, and the fourth to the
seventh or eighth are half again as long as broad; the segments following gradually
decrease in length, the third and fourth from the end being only slightly longer than
broad. The terminal segments are again about half again as long as broad. The distal
ventral ends of the segments are slight]}' prominent, and the distal dorsal ends of the
outer segments are sometimes slightly thickened. The opposing spine is minute,
terminally situated, and directed obliquely forward; it is often barely indicated or
entirely absent. The terminal claw is nearly as long as the penultimate segment,
moderately slender and moderately curved.

The ends of the basal rays are usually visible as dorsoventrally elongate tubercles
in the angles of the calyx, but are sometimes quite concealed.

The radials are concealed. The IBri are usually entirely concealed in the median
line but slightly visible over the ends of the basal rays; they are sometimes visible as a
narrow line along the proximal border of the axillaries. The IBr2 (axillaries) are rhom-
bic, twice as broad as long, with all the sides somewhat incurved, and rise in the proximal
half to a large rounded tubercle. The IIBr series are 4(3+4), rarely 2, in close apposi-
tion and strongly flattened laterally.

The 12-14 arms are 100 mm. long. The first eight or nine brachials are wedge-
shaped or almost oblong, about twice as broad as long, and are more or less tubercular.
The brachials following are triangular, about as long as broad, becoming in the ter-
minal portion of the arms wedge-shaped and longer than broad.

In arms arising from a IBr axillary the first syzygy is between brachials 3 + 4, the
second between brachials 14+15 or 15+16, and the distal intersyzygial interval is
from 6 to 16 oblique muscular articulations. In arms arising from a IIBr axillary the
first syzygy is between brachials 1+2 or 2 + 3.

The pinnules resemble those of G. angusticalyx, but the expansion of the genital
pinnules is somewhat more marked.

272 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The disk is completely covered with a pavement of small plates. The brachial and
pinnule ambulacra are well plated, and there are large irregular plates over the gonads.

The color in life is yellow.

Localities. — Albatross station 5236; east coast of Mindanao, north of Lianza Bay;
Magabao Island (S.) bearing N. 85° W., 9.10 miles distant (lat. 8°50'45" N., long.
126°26'52" E.); 903 meters; bottom temperature 5.11° C.; fine gray sand; May 11,

1908 [A. H. Clark, 1909, 1912, 1918] (3, U.S.N.M., 25464 [type], 35688).

Albatross station 5349; Palawan Passage; Point Tabonan bearing N. 85° E., 42.5
miles distant (lat. 10°54'00" N., long. 118°26'20" E.); 1,334 meters; bottom tempera-
ture 4.83° C.; coral sand; December 27, 1908 (4, U.S.N.M., 35956).

Albatross station 5367; Verde Island Passage; Malabrigo Light bearing N. 81° E.,
8 miles distant (lat. 13°34'37" N., long. 121°07'30" E.); 329 meters; sand; February
22, 1909 (1, U.S.N.M., 35896).

Geographical range. — -Philippine Islands.

Bathymetrical range. — From 329 to 1,334 meters.

Thermal range.— From 4.83° to 5.11° C.

History. — This species was described under the name of Pachylometra levigata in

1909 from a specimen from Albatross station 5236. In my memoir on the crinoids of
the Indian Ocean published in 1912 Pachylometra levigata was listed and the range
and synonymy were given. In my report on the unstalked crinoids of the Siboga
Expedition published in 1918 levigata was included in the key to the species of Pachylo-
metra and the synonymy and range were given.

GLYPTOMETRA LATA (A. H. Clark)

PLATE 28, FIGURES 84-86; PLATE 29, FIGURE 88
[See also vol. 1, pt. 2, figs. 306, p. 223, 658, p. 329.]

Antedon lata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 140 (description; Albatross station

4918).
Charitometra lata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed) ; Proc. U. S.

Nat. Mus., vol. 34, 1908, p. 228 (compared with Ch. [Calyptometra] lateralis), p. 312 (Sagami Bay,

Japan) .
Glyptometra lata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 19 (listed); vol. 25, 1912,

p. 80 (compared with G. [Perissometra] timorensis) ; Crinoids of the Indian Ocean, 1912, p. 224

(synonymy; locality); Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese

species; range and its significance).
Perissometra lata A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed);

Unstalked crinoids of the Siboj/o-Exped., 1918, p. ix (relationship with P. timorensis), p. 177 (in

key; range), p. 182 (references). — GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5,

No. 6, 1922, p. 121 (compared with P. aranea); Vid. Medd. Dansk Nat. Foren. K0benhavn, vol.

83, 1927, p. 35; Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 8.

Diagnostic features. — -The cirri, which are arranged in 15 columns on the centrodor-
sal, are up to 25 mm. in length and are composed of 15-18 segments, of which the earlier
are longer than broad and the distal are about as long as broad or broader than long;
the 10 arms are 115-130 mm. long; and the IBr series and lower brachials are coarsely
rugose, but their borders are not everted.

Description. — The centrodorsal is a thick disk with the bare polar area moderate
or large and coarsely tubercular. The cirrus sockets are arranged in one and a more or

A MONOGRAPH OF THE EXISTING CRINOIDS 273

less complete second row and in 15 columns, 3 in each radial area, the middle column
in each radial area consisting of a single cirrus near the dorsal pole. In the Misaki
specimen there are 10 cirri about the proximal rim of the centrodorsal, 7 of these having
another just beneath it, and 5 smaller ones midradial in position about the dorsal pole.

The cirri are XV-XXII, 15-18, up to 25 mm. in length. The first segment is short,
those following increasing in length to the sixth and seventh, which are from slightly
longer than broad to about one-third again as long as broad, thence remaining uniform,
or slowly decreasing to about as long as broad or, in the stoutest cirri, even slightly
broader than long, toward the tip. The segments beyond the basal portion are very
slightly flaring, and those in the distal third of the cirri have a slight well rounded tuber-
cle dorsally at the distal end. The opposing spine is well developed, conical, stout, and
blunt, terminal, and leaning slightly forward. The terminal claw is about as long as
the penultimate segment, moderately stout, tapering more rapidly in the proximal
third than distally, and moderately curved, most strongly in the basal third.

The ends of the basal rays are visible as dorsoventrally elongate tubercles in the
angles of the calyx.

The radials are concealed or more or less of them may be visible beyond the rim of
the centrodorsal. The IBn are very short, bandlike, broadly V-shaped, with more or
less coarsely crenulatc edges and a central more or less circular low tubercle. The
IBr2 (axillaries) are rhombic, more than twice as broad as long, with the lateral angles
truncated and the lateral borders slightly everted. The distal sides are rather strongly
concave and there is a median tubercle narrower than that on the IBrj and dorsoven-
trally elongate in the proximal two-thirds. The elements of the IBr series and the
first two brachials are closely appressed and sharply flattened laterally.

The 10 arms are 115-130 mm. long. The two first brachials are somewhat wedge-
shaped, longer exteriorly than interiorly, the second rather larger than the first. They
have a low and rather narrow raised median line and slightly everted borders. The
first syzygial pair (composed of brachials 3 + 4) is oblong, about twice as broad as long;
each element has a low median rounded tubercle, or the hypozygal may have a row of
4 or 5 small low rounded tubercles. The twelfth brachial is regularly oblong. The
brachials between the first syzygial pair and the twelfth are slightly wedge-shaped,
more than twice as broad as long with an uneven surface though not tubercular. After
the twelfth the brachials become triangular, slightly broader than long, soon becoming
about as long as broad. The lower triangular brachials have each an obsolescent median
rounded tubercle. The distal ends of the brachials may be slightly produced, this
condition, if present, tending to become more accentuated distally.

Syzygies occur between brachials 3+4, again at about brachials 13+14, and
distally at intervals of from 8 to 1 1 muscular articulations.

PI is 10 mm. long, comparatively slender and tapering rather gradually from the
base to the tip, and is composed of about 40 short segments of which the basal 8 or
10 are flattened exteriorly and rather broad. P2 is much shorter than PI with about 23
segments of which the proximal 8 or 9 are much expanded laterally. PS resembles
P2 but is somewhat shorter and the 6 basal segments" are even more expanded, reaching
a maximum on the third and fourth, thence tapering to the tip. The following pin-
nules to about the fiftieth brachial are similar, but the number of segments increases
from 12 on P4 to 20 on the pinnule of the fiftieth brachial; as the great lateral expansion

274 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

is always confined to the first 6 segments, reaching a maximum on the third or fourth
then gradually decreasing to the sixth which distally is of normal diameter, the expanded
segments covering the gonads progressively occupy less and less of the total length of
the pinnule; while in the earlier pinnules they take up most of the length, in the pinnule
of the fiftieth brachial they occupy barely the proximal third. The distal pinnules are
11 mm. long, slender, with about 20 elongated segments.

The disk is completely plated. The brachial and pinnule ambulacra are well
plated. The sacculi are very small and inconspicuous.

The color in life is yellow to yellowish brown.

Notes. — A small specimen collected with the type has the arms 80 mm. long. In
general it resembles the type, but the ends of the basal rays are more prominent, the
dorsal surface of the IBr series and lower brachials is smooth, and the brachials are all
proportionately longer.

The specimen from Misaki is larger than the type, having the arms 130 mm. in
length. The elements of the IBr series and the first 2 brachials have a broad rounded
median ridge instead of the broad central tubercle seen in the typej The general
appearance is somewhat less rugged, though the style of ornamentation is the same.
In its characters it is somewhat intermediate between the type and the small specimen
collected at the same station. The outer ends of the radials are visible.

Localities. — Albatross station 4918; Eastern Sea, 10 to 20 miles southwest of the
Koshika Islands; Gwaja Shima bearing S. 38' E., 34 miles distant (lat. 30°22'00" N.,
long. 129°08'30" E.); 660 meters; bottom temperature 5.94° C.; gray sand, globigerinae,
and broken shells; August 13, 1906 [A. H. Clark, 1907, 1908, 1909, 1912, 1915, 1916,
1918; Gislen, 1922, 1927, 1928] (2, U.S.N.M., 22628).

Sagami Bay; off Misaki; Alan Owston, yacht Golden Hind, July 1902 [A. H. Clark,
1908, 1912, 1918] (1, U.S.N.M., 35684 [original No. 6969]).

History. — This species was described in 1907 under the name of Antedon lata from
a large specimen from Albatross station 4918. In my first revision of the genus Antedon
published later in 1907 lata was referred to the new genus Charitometra. In my report,
published in 1908, upon Alan Owston's collection of crinoids from southern Japan, which
was purchased by Dr. Frank Springer and presented by him to the National
Museum, I recorded another specimen of this species from off Misaki. In 1908 I
compared Charitometra lata with a new species, Charitometra (Pachylometra) lateralis.
On the establishment of the genus Glyptometra in 1909 lata was removed to it. In my
memoir on the crinoids of the Indian Ocean published in 1912 Glyptometra lata was
listed and the synonymy and range were given. In a short paper published in the same
year I compared Glyptometra lata with a new species, G. timorensis. In 1915 Glyptometra
lata was listed as a characteristic species of southern Japan and the range was given.
On the creation of the new genus Perissometra in 1916 lata was placed in it. In my
memoir on the unstalked crinoids of the Siboga Expedition published in 1918 lata was
included in the key to the species of Perissometra, the synonymy and localities were
given, and its relationships with P. (Glyptometra) timorensis were discussed.

In 1922 Prof. Torsten Gislen compared Perissometra lata with his new species P.
aranea (=Parametra orion), and in 1927 he remarked that lata, with crassa and perhaps
other species of Perissometra, must be referred to Glyptometra. In 1928 he said that
lata, with patula, timorensis, flexilis, and aranea, should be assigned to Perissometra.

A MONOGRAPH OF THE EXISTING CRINOIDS 275

GLYPTOMETRA INVENUSTA (A. H. Clark)

PLATE 29, FIGURE 89

Pachylometra invenusta A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 149 (description;
11°46'30" N., 93°16'00" E. ; 569 fathoms) ; Crinoids of the Indian Ocean, 1912, p. 220 (syn-
onymy; detailed description; locality), fig. 40, p. 221.

Perissometra invenusta A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 607 (listed) ;
Unstalked crinoids of the Si&oga-Exped., 1918, p. 178 (in key; range), p. 181 (references). —
GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22.

Diagnostic features. — The cirri, which are arranged in 15 columns on the centro-
dorsal, are 30-34 nun. long with 20-21 segments, of which the distal are markedly
longer than broad; the 12 arms are 170 mm. long; and the division series and lower
brachials have a rather fine rugose ornamentation, the proximal brachials each bearing
a median small rounded tubercle.

Description. — The original description of this species is quite unsatisfactory. I
said that this species is in general similar to Glyptometra macilenta, but differs in many
details. The centrodorsal is not described. In the figure it is shown as a broadly
truncated cone. The cirrus sockets in the radial area shown are 5 in number; there are
3 along the proximal border and 2 below, situated under the spaces between those above.
This presumably indicates a species with the cirri in 15 columns, though the centrally
situated cirrus socket may be adventitious.

The cirri are XXIII, 20-21, from 30 to 34 mm. long, rather slender, resembling
those of Glyptometra macilenta. The proportions of the component segments are the
same as in that species, but the distal edges of the segments are slightly more thick-
ened, giving the cirri as a whole a somewhat rougher appearance.

The IIBr series are 4(3 + 4). The elements of the IBr and IIBr series and the first
two brachials exteriorly and first three ulteriorly are in close lateral apposition and
sharply flattened laterally, with the apposed edges somewhat everted. The ornamen-
tation of the ossicles of the IBr and IIBr series is essentially as in G. macilenta.

The 12 arms are 170 mm. long, slender, as in G. macilenta. The brachials have the
same proportions as those of G. macilenta, but the proximal subquadrangular brachials
have the distal ends thickened and everted, and the remaining brachials have rather
prominently overlapping distal edges. In the figure the proximal discoidal brachials
are shown each with a small central tubercle.

The distal intersyzygial interval is 4 or 5 oblique muscular articulations.

The pinnules resemble those of G. macilenta, but the genital pinnules are more
swollen than are those of that species.

The color in alcohol is dull yellowish white.

Locality.— OS South Andaman Island (lat. 11°46'30" N., long. 93°16'00" E.);
1,040 meters; bottom temperature 4.44° C.; green mud and foraminiferal ooze; Investi-
gator [A. H. Clark, 1909, 1912, 1916, 1918; Gislen, 1934] (1, I. M.).

History. — Pachylometra invenusta was originally described in 1909 from a single
specimen dredged by the Royal Indian Marine Survey steamer Investigator off South
Andaman Island. It was redescribed and figured in 1912. On the establishment of
the genus Perissometra in 1916 invenusta was transferred to it. In my memoir on the
unstalked crinoids of the Siboga Expedition published in 1918 invenusta was included
in the key to the species of the genus Perissometra and the synonymy and locality were

276 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

given. In 1934 Prof. Torsten Gislen listed Perissometra invenusta among the comatu-
lids with the Heterometra bengalensis type of arm division.

GLYPTOMETRA LATERALIS (A. H. Clark)

PLATE 29, FIGURE 87

[See also vol. 1, pt. 1, fig. 370, p. 299; pt. 2, figs. 240, p. 197, 303, p. 223, 676, 677, p. 338, 868-873,

p. 425, pi. 54, fig. 1347.]

Charitomelra lateralis A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214 (in key), p. 226 (de-
scription; Albatross station 4179; also stations 4177, 4180).

Glyptomelra lateralis A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 19 (listed); vol. 25,
1912, p. 81 (comparison with G. [Perissometra] timorensis); Crinoids of the Indian Ocean, 1912,
p. 224 (synonymy; locality); Bernice P. Bishop Mus. Bull. 195, 1949, p. 75 (Albatross stations
4177, 4179, 4180), p. 116 (station data).

Calyplomelra lateralis A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (listed);
Unstalked crinoids of the Siboga-Exped., 1918, p. 189 (references).

Diagnostic features . — The cirri, which are arranged in 15 columns on the ceutro-
dorsal, are 30-40 mm. long with 15-21 segments of which the distal are*markedly longer
than broad; the 10 (rarely 11) arms are 160-180 mm. long and the division series and
lower brachials are coarsely rugose with the lateral edges everted, each of the proximal
brachials with a low broad hump.

Description. — The centrodorsal is very thick discoidal, or almost columnar, more
rarely truncated conical. The closely crowded marginal cirrus sockets are arranged
roughly in 2 rows and 15 columns.

The cirri are XXX, 15-21 (usually 16-19), from 30 mm. to 40 mm. in length. The
first segment is about half as long as broad, the second is almost as long as broad, the
third is rather longer than broad, and the remainder are about half again as long as
broad. The last 4 or 5 segments have the median portion of the distal dorsal edge
rather prominent, and the penultimate bears a small opposing spine which is usually a
blunted tubercle, but sometimes sharp and directed obliquely distally. The terminal
claw is not so long as the penultimate segment, and is moderately slender and moderately
curved.

The ambulacra of the arms and pinnules are extensively plated.

The ends of the basal rays are visible as rounded tubercles in the interradial angles
of the calyx.

The radials, and usually also all the IBri, are concealed by the centrodorsal. The
IBr2 (axillaries) are low and broad, about three times as broad as long, with the distal
angle broad and usually more or less blunt or rounded. IIBr series, when present, are 2.

The 10 or 1 1 arms are 160 to 180 mm. in length. The first two brachials are oblong,
very short, three or four times as broad as long. The first syzygial pair (composed of
brachials 3+4) is about twice as broad as long. The following eight or nine brachials
are wedge-shaped, about twice as broad as long, those succeeding becoming triangular,
and after the eighteenth as long as broad, the terminal brachials becoming wedge-
shaped again and elongate. The IBr2 and the first three brachials have the proximal
and distal edges everted and crenulate, often extravagantly so, dovetailing with the
edges of the adjacent segments. The lateral edges of these ossicles are strongly everted
and thin, those on adjacent arms being closely appressed and together standing out as
narrow interradial keels which are equal in height to the proximal and distal eversion

A MONOGRAPH OF THE EXISTING CRENOIDS 277

of the segments. The proximal three-fourths of the IBr2 bears a prominent broadly
rounded median ridge which becomes higher proximally, forming a tubercle with a
similar ridge on the IBr, when that ossicle is visible. Similar rounded ridges occur on
the proximal portion of the second brachials and the distal portion of the first brachials.
The third brachial has a slight rounded median tubercle. The lateral edges of the
proximal brachials up to about the fifteenth are turned outward and produced into a
thin marginal flange, this feature becoming less and less marked distally and usually
not noticeable after the fifteenth. The elements of the IBr series and the first 5 or 6
brachials are sharply flattened laterally and are in very close lateral apposition. The
brachials, except for those at the bases of the arms, are rather strongly overlapping with
finely serrate distal edges.

Syzygies occur between brachials 3+4, again in the vicinity of brachials 15+16,
and distally at intervals of from 5 to 11 (usually 5 to 7) muscular articulations.

PI is 16 mm. long, tapering rapidly from a very broad base 2 mm. in width to
about the middle, then remaining slender and flagellate to the tip. It is composed of
35 or more segments of which the basal are very broad, much broader than long, and
those following become narrower and relatively longer to about the middle of the
pinnule beyond which point they are about as long as broad. The whole pinnule is
somewhat flattened, very much so basally. P2 is 14 mm. long, similar to PI but not
so much expanded basally. P3 is 12 mm. long, rather stiffer than, and not flagellate
like, Pt and P2, with 20 segments of which the lower are evenly expanded, this expansion
increasing to the fourth or fifth, then gradually decreasing and ending at the eighth.
The segments as far as the fifth or sixth are about twice as broad as long, and those
succeeding increase in relative length, the comparatively slender segments following the
eighth being about twice as long as broad. P4 and the following pinnules are similar,
but with the expansion of the lower segments more marked. Distally the basal expan-
sion gradually occupies less and less of the pinnule and at the same time the pinnules
become longer so that they have an increasingly long slender tip. After about Pu the
basal expansion is not noticeable, the pinnules, though stout basally, tapering evenly from
the base to the tip. The distal pinnules are 15 mm. long with the first segment short,
slightly wedge-shaped, rather over twice as broad as long, the second similar but rela-
tively longer, and the remainder about half again as long as broad, becoming about
twice as long as broad distally.

The color in life is ochre yellow, the cirri clear lemon yellow (W. K. Fisher). The
containing alcohol is stained either a deep orange red or emerald green.

Notes. — In the specimen from Albatross station 4180 with the arms 80 mm. long
both the elements of the IBr series are visible, and the ends of the basal rays are promi-
nent as vertically elongate tubercles in the angles of the calyx. The very broad char-
acter of the elements of the IBr series and lower brachials is marked, as is the eversion
of their edges, especially the lateral edges; but the proximal and distal edges as yet
have not taken on the crenulate feature characteristic of the fully grown. In this
specimen one of the IBr axillaries bears a regenerating pair of arms replacing an arm
lost, the IlBr series being 2, so that there are 11 arms.

In the smallest specimen the radials are visible; these have a pronounced rounded
median ridge. The ends of the basal rays are prominent and project rather more than
in the specimen just noticed. The unusual broadness of the IBr series and lower

278 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

brachials is marked even at this early stage, though the brachials following are much
elongated. The eversion of the lateral edges of the elements of the IBr series and lower
brachials is already apparent.

Localities. — Albatross station 4177; Hawaiian Islands, off Niihau; Kawaioa Point
bearing S. 54° W., 17.5 miles distant; 824-583 meters; bottom temperature 5.00° C.;
gray sand and globigerinae ; August 12, 1902 [A. H. Clark, 1908, 1909, 1912, 1916, 1918]
(l.U.S.N.M., 35639).

^4/toross station 4 179; off Niihau jKawahioa Point bearing S. 60°45' W., 19.2 miles
distant; 691-779 meters; bottom temperature 5.55° C. ; coarse sand, rocks, and pebbles;
August 12, 1902 [A. H. Clark, 1908, 1909, 1912, 1916, 1918] (5, U.S.N.M., 22688 [type],
35638; M. C. Z., 353).

Albatross station 4180; off Niihau; Kawahioa Point bearing S. 58° W., 19.5 miles
distant; 779-762 meters; bottom temperature 5.05° C. ; pebbles, globigerinae, and rocks;
August 12, 1902 [A. H. Clark, 1908, 1909, 1912, 1916, 1918] (2, U.S.N.M., 35629).

Geographical range. — Known only from off Niihau, Hawaiiar^Islands.

Bathymetrical range. — Between 583 and 824 meters, but not definitely recorded
from either extreme.

Thermal range. — From 5.00° to 5.55° C.

History. — This species was described as Charitometra lateralis in 1908 from one of
six specimens from Albatross station 4179; at the same time other specimens were
recorded from stations 4177 and 4180 and notes were given on them. Charitometra
lateralis was said to belong to the same division of the genus as tuberosa from the Philip-
pines and lata from Japan, differing from both in its larger size, much longer cirrus
segments which are about half again as long as broad instead of about as long as broad,
the prominent eversion of the lateral edge of the elements of the IBr series and lower
brachials, and the absence of the dorsal carination of the lower part of the arm which is
so characteristic a feature of tuberosa.

In 1909 I transferred lateralis to the new genus Glyptometra, and in 1912 compared
it with a new species, 0. timorensis. In my memoir on the crinoids of the Indian Ocean
published later in 1912 Glyptometra lateralis was listed and the range and synonymy
were given. In 1916 I established the genus Calyptometra for this species, and in my
report on the unstalked crinoids of the Siboga Expedition published in 1918 I listed
Calyptometra lateralis with the synonymy and range.

GLYPTOMETRA sf.

Locality. — Off Pratas reef, southeast of Hong Kong (lat. 21°10' N., long. 117°30'
E.); 704 meters; Captain Suensson, May 22, 1911 (fragments, C. M.).

Notes. — Fragments of a specimen of a species of Glyptometra of the G. invenusta
type from this locality are in the Copenhagen Museum. One postradial series in situ
has one IIBr 4(3+4) series and three arms. The IBri are granulated, and the edges
of the axillaries all around are finely tubercular. The cirri are 40 mm. long with
19-20 segments of which the fourth is about as long as broad, the sixth and seventh
are nearly twice as long as broad, and the outermost are half again as long as the
proximal width; the distal dorsal edge of the outer segments is slightly thickened.

A MONOGRAPH OF THE EXISTING CRINOIDS 279

Genus CRINOMETRA A. H. Clark

Comatula (part) POURTALES, Bull. Mus. Comp. Zool., vol. 1, No. 6, 1868, p. 111.

Antedon (part) POURTALES, Bull. Mus. Comp. Zool., vol. 1, No. 13, 1869, p. 357, and following authors.

Actinometra (part) P. H. CARPENTER, Bull. Mus. Comp. Zool., vol. 9, No. 4, 1881, p. 162.

Spinifera group (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 212.

Granulifcra group (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 241.

Brevipinna group MINCKEHT, Arch. Naturg., Jahrg. 71, vol. 1, Heft 2, August 1905, p. 224 (defini-
tion; represented by Antedon brevipinna only).

Charitometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.

Crinomelra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22 (diagnosis; genotype
Comatula brevipinna Pourtales, 1868), p. 144 (ornamentation compared with that of Mariamelra);
Vid. Medd. Nat. Foren. K0benhavn, 1909, p. 147 (agrees in the variation in the IIBr series
with Pachylometra its East Indian representative); Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10
(represents in the West Indies the East Indian Pachylometra and Glyptometra); Crinoids of the
Indian Ocean, 1912, p. 13 (corresponds to the East Indian Pachylometra and Glyptometra), p. 24
(range in detail; for zoogeographic purposes may well be considered as one with Pachylometra
and Glyptometra). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 286 (discus-
sion).— A. H. CLARK, Internat. Rev. Gesamt. Hydrobiol. und Hydrogr., 1914, pp. 4 and fol-
lowing (represents Pachylometra and Glyptometra in the Atlantic; range and its significance);
Die Crinoiden der Antarktis, 1915, p. 181 (range; represents in the Atlantic the Indo-Pacific
Pachylometra and Glyptometra). — F. W. CLARKE and WHEELER, U. S. Geol. Surv. Prof. Pap.
90-L, 1915, p. 195 (inorganic constituents of the skeleton); Prof. Pap. 102, 1917, pp. 23 and fol-
lowing (same). — A. H. CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 171 (in key;
range), p. 186 (discussion, with list of included described forms); Journ. Washington Acad.
Sci., vol. 9, No. 5, 1919, p. 136 (arm bases compared with those of Holopus) ; Univ. Iowa Studies
in Nat. Hist., vol. 9, No. 5, 1921, p. 12 (confined to the West Indies), p. 19 (in key). — F. W.
CLARKE and WHEELER, U. S. Geol. Surv. Prof. Pap. 124, 1922, p. 20 (inorganic constit-
uents of the skeleton). — A. H. CLARK, The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea,
1923, p. 40 (range), p. 51 (in key). — GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 231 (irregular
division series). — PELSENEER, Bull. Soc. Zool. France, vol. 53, 1928, p. 173 (parasitized by
Eulima [Sabinella], sp.).— GISLEN, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93, 1933,
pp. 480-482; Kungl. Fysiogr. Siillsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 23, 25, 29.

Diagnosis. — -A genus of Charitometridae in which the genital pinnules taper evenly
from the usually more or less broadened earlier segments to a delicate tip, the portion
beyond the gonad being much longer than the gonad itself; the division series and arm
bases are rounded dorsally, with or without a fine abruptly raised median line and a
tubercular ornamentation on the division series and arm bases ; and the oral pinnules are
markedly longer than the genital and distal pinnules, which are unusually short.

Geographical range. — From the Yucatan Bank, the Florida Keys, northern Cuba,
and the southern Bahamas eastward and southward along the Antillean chain to
Barbados and Grenada; also St. Helena.

Bathymetrical range. — From 139 to 707 meters.

Thermal range. — From 8.33° to 18.20° C.

History. — -The first description of a species of this genus was by Count L. F.
de Pourtales who in 1868 referred it to the genus Comatula, transferring it to Antedon in
the following year. It was referred to Actinometra by Dr. P. H. Carpenter in 1881, but
transferred to Antedon in 1883. In his memoir on the comatulids of the Challenger
Expedition published in 1888 Carpenter placed different forms of the species in his
Spinifera and Granulifera groups of Antedon, and in 1905 Minckert established the
Brevipinna group for it.

280 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

In my revision of the genus Antedon published in 1907 I transferred it to the new
genus Charitometra, and in 1909 established the genus Crinometra with Comatula
brevipinna Pourtales, 1868, as the genotype. In 1933 Prof. Torsten Gislen discussed
the genus Crinometra at considerable length and redefined it.

CRINOMETRA BREVIPINNA (Ponrtalfes)

PLATE 30, FIGURE 90; PLATE 31, FIGURE 93

Comatula brevipinna POURTALES, Bull. Mus. Comp. Zool., vol. 1, No. 6, 1868, p. Ill (off Havana, 270
fathoms; Corwin).— P. H. CARPENTEB, Trans. Linn. Soc. (Zool.), ser. 2, vol. 2, 1879, p. 29 (unable
to place it in Antedon or Adinometra) . — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912,
p. 313 (original description republished) .

Antedon brevipinna POURTALES, Bull. Mus. Comp. Zoo!., vol. 1, No. 13, 1869, p. 357 (not obtained
since 1867). — P. H. CARPENTER, Proc. Zool. Soc. London, 1882, 1883, p. 746 (specific formula);
Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 212 (in key), p. 378 (locality).— HARTLAUB,
Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrical relation-
ships) .— MINCKERT, Arch. Naturg., Jahrg. 71, 1905, vol. 1, Heft 1, pp. 169 and following
(syzygies; regeneration)/ — HAMANN, Bronn's Klassen und Ordnungen fles Tier-Reichs, vol. 2, Abt.
3, 1907, pp. 1578, 1581 (listed). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 311
(Blake stations 34, 45, 101, 157, 158, 193, 198, 219, 232, 241, 249, 259, 269, 272; Blake, without
locality; Investigator, apparently off Martinique; Corwin station 2), pi. 1, figs. 17, 18, 21-23; pi. 3,
figs. 1, 3, pi. 4, figs. 1, 2. 5-7, pi. 11, figs. 1-9, pi. 12, figs. 3-5.— A. H. CLARK, Unstalked crinoids
of the Sibo(?a-Exped., 1918, p. 187 (referred to Crinometra).

Antedon granulifera POURTALES, Bull. Mus. Comp. Zool., vol. 5, No. 9, 1878, p. 215 (description;
Blake station 45).— BELL, Proc. Zool. Soc. London, 1882, p. 533 (listed).— P. H. CARPENTER,
Proc. Zool. Soc. London, 1882, 1883, p. 746 (corrected specific formula); Challenger Reports,
Zoology, vol. 26, pt. 60, 1888, p. 239 (type of the Granulifera group; discussion), p. 241 (in key),
p. 380 (Caribbean Islands, 101-120 fathoms [Blake stations 45 and 157]).— HAMANN, Bronn's
Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1582 (listed).— HARTLAUB, Mem.
Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 298 (redescription of the type specimen; notes; Blakt.
stations 45, 34, off Martinique, "Steamer Enterprise, Capt. Cole"), pi. 1, figs. 24, 25, pi. 5, figs.
1-13, pi. 12, figs. 1, 2, 6-8.— A. H. CLARK, Unstalked crinoids of the Si&offo-Exped., 1918, p. 187
(referred to Crinometra) .

Adinometra granulifera P. H. CARPENTER, Bull. Mus. Comp. Zool., vol. 9, No. 4, 1881, p. 162 (dis-
cussion).—HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No, 4, 1912, pp. 298, 299 (synonym of
Antedon granulifera).

Antedon pourlalesii VON GRAFF, Bull. Mus. Comp. Zool., vol. 11, No. 7, 1883, p. 129 (Blake station
241; myzostomes); Challenger Reports, Zoology, vol. 10, pt. 27, 1884, pp. 14, 18 (myzostomes),
p. 38 (Blake station 241; myzostomes). — BRA UN, Centralbl. Bakteriol. und Parasitenkunde, vol. 3,
1888, p. 185 (myzostomes; after von Graff).

Antedon pourtalesi P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 212 (in
key), p. 379 (Caribbean Islands, 124-262 fathoms). — HAMANN, Bronn's Klassen und Ordnungen
des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — HARTLAUB, Mem. Mus. Comp. Zool.,
vol. 27, No. 4, 1912, p. 280 ( = brevipinna) , p. 309 (in Spinifera group; history; synonym of
brevipinna). — A. H. CLARK, Unstalked crinoids of the Siboga-~Exped., 1918, p. 187 (referred to
Crinometra) .
Brevipinna group MINCKERT, Arch. Naturg., Jahrg. 71, vol. 1, Heft 2, August 1905, p. 224 (definition;

represented by Anledon brevipinna only) .
Charitometra brevipinna A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed);

vol. 52, part 2, 1908, p. 227 (compared with Ch. smithi).

Charitometra granulifera A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed). —
HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 298 (in synonymy of Antedon
granulifera) .

Charilometra pourtalesi A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed).
Charitometra imbricata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 266 (new name for

A MONOGRAPH OF THE EXISTING CRINOIDS 281

Antedon granulifera P. H. Carpenter, 1888, [erroneously] supposed not of Pourtales, 1878),
fig. 3 (three consecutive pinnules on the same side of an arm); Smithsonian Misc. Coll., vol. 52,
pt. 2, 1908, p. 227 (compared with Ch. smithi). — A. H. CLARK, Unstalked crinoids of the Siboga-
Exped., 1918, p. 187 (referred to Crinometra).

Pachylometra imbricata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22 (listed).

Pachylometra brevipinna A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22 (listed).

Crinometra brevipinna A. H. CLARK, Vid. Medd. Naturhist. Foren. K0benhavn, 1909, p. 146
(supposed variation in the IIBr series really nonexistent). — HARTLAUB, Mem. Mus. Comp.
Zool., vol. 27, No. 4, 1912, p. 311 (in the synonymy of Antedon brevipinna). — A. H. CLARK,
The Danish Ingolf-'Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range); Journ. Linn. Soc. (Zool.),
vol. 36, No. 249, April 1929, p. 658 (off St. Thomas; 240 fathoms) .— GISLEN, Vid. Medd. Dansk
Nat. Foren. K0benhavn, vol. 93, 1933, p. 481.

Crinometra pukhra A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 644 (description; Albatross
stations 2319-2350). — HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322, footnote
( = Antedon brevipinna var. pourtalesi, pi. 4, fig. 1, according to A. H. Clark). — A. H. CLARK,
Unstalked crinoids of the Siboga-'Exped., 1918, p. 187 (listed); Bull. U. S. Nat. Mus., No. 82,
vol. 1, pt. 2, 1921, fig. 682, p. 338.— GISLEN, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93,
1933, p. 481; Kungl. Fysiograf. Sallsk. Hand!., new ser., vol. 45, No. 11, 1934, pp. 20, 25, 26.—
H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 10 (Atlantis station
3326; notes).

Crinometra margaritacea A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 645 (description;
Albatross station 2154); Unstalked crinoids of the /S»6o0a-Exped., 1918, p. 187 (listed); Bull.
U. S. Nat. Mus. No. 82, vol. 1, pt. 2, 1921, fig. 683, p. 339 — GISLEN, Kungl. Fysiograf. Sallsk.
Handl., new ser., vol. 45, No. 11, 1934, p. 25.

Crinometra concinna A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 646 (description; Albatross
station 2324).— HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 331, footnote
( = Antedon brevipinna var. elegans according to A. H. Clark). — F. W. CLARKE and W. C. WHEEL-
ER, U. S. Geol. Surv. Prof. Pap. 90-D, 1914, pp. 34 and following (inorganic constituents of the
• skeleton); Prof. Pap. 102, 1917, pp. 20 and following (same). — A. H. CLARK, Unstalked crinoida
of the Siboga-Exped., 1918, p. 187 (listed) ; Bull. U. S. Nat. Mus. No. 82, vol. 1, pt. 2, 1921, fig. 678,
p. 338.— F. W. CLARKE and W. C. WHEELER, U. S. Geol. Surv. Prof. Pap. 124, 1922, p. 17 (Alba-
tross station 2324; inorganic constituents of the skeleton). — GISL^N, Kungl. Fysiograf. Sallsk.
Handl., new ser., vol. 45, No. 11, 1934, pp. 20, 24, 25.

Crinometra insculpta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 646 (description; Albatross
station 2753); Unstalked crinoids of the Siboga-Exped., 1918, p. 187 (listed); Bull. U. S. Nat.
Mus., No. 82, vol. 1, part 2, 1921, figs. 680, 681, p. 338; The Danish /nffoi/-Exped., vol. 4, No. 5,
Crinoidea, 1923, p. 40 (range). — GISL&N, Vid. Medd. Dansk. Nat. Foren., K0benhavn, vol. 93,
1933, pp. 480, 481; Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 20, 30.—
H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941 p. 10 (Atlantis stations
2950, 2980, 2980A, 2980B, 2982A, 2982B, 2982C, 2983, 2983A, 2984, 2987, 2999, 3000, 3303,
3326, 3372, 3388, 3425, 3430, 3431, 3432, 3434, 3435, 3436, 3438, 3466, 3467, 3478, 3482).

Crinometra gemmata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 647 (description; Albatross
station 2330).— HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 298 (in synonymy
of Antedon granulifera), p. 300 (pi. 5, fig. 9 [granulifera] is this species according to A. H. Clark).—
A. H. CLARK, Unstalked crinoids of the <Si6osa-Exped., 1918, p. 187 (listed); Bull. U. S. Nat. Mus.
No. 82, vol. 1, part 2, 1921, fig. 679, p. 338; The Danish 7«goZ/-Exped., vol. 4, No. 5, Crinoidea,
1923, p. 40 (range).— GISLEN, Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934,
p. 26.

Antedon angusticalyx HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 287 (description;
Blake station 157 [2; these are the specimens upon which' Carpenter's depth record of 120 fathoms
given in 1888 is based]), pi. 4, figs. 3, 4, pi. 12, fig. 9, pi. 13, fig. 2.— A. H. CLARK, Unstalked cri-
noids of the .Si'bojo-Exped., 1918, p. 187 (referred to Crinometra).

Antedon brevipinna var. decora HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in
key), p. 324 (description; St. Vincent; Blake stations 34, 158, 157), pi. 11, figs. 4, 9. — A. H. CLARK,

843803—50 19

282 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Unstalked crinoids of the Siboga-Exped., 1918, p. 187 (referred to Crinometra) . — GisLfiN, Vidensk.
Medd. Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 480.

Anledon brevipinna var. gracilis HARTLATJB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322
(in key), p. 328 (description; Blake station 157), pi. 12, fig. 3. — A. H. CLARK, Unstalked crinoids

of the Siboga-Exped., 1918, p. 187 (referred to Crinometra).— GISL£N, Vid. Medd. Dansk Nat.

Foren. K0benhavn, vol. 93, 1933, p. 480.
Antedon brevipinna var. pulchra HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322

(in key), p. 329 (description; no locality). — A. H. CLARK, Unstalked crinoids of the Siboga-Eiped.,

1918, p. 187 (referred to Crinometra).
Antedon brevipinna var. elegans HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in

key), p. 331 (description; Blake station 193), pi. 4, fig. 7, pi. 11, fig. 5.— A. H. CLARK, Unstalked

crinoids of the Szboffa-Exped., 1918, p. 187 (referred to Crinometra). — GISL^N, Vid. Medd. Dansk

Nat. Foren. K0benhavn, vol. 93, 1933, p. 481.
Anledon brevipinna var. tuberosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in

key), p. 333 (description; no locality; Blake stations 219, 198), pi. 11, fig. 3.— A. H. CLARK,

Unstalked crinoids of the Siboga-Exped., 1918, p. 187 (referred to Crinometra). — GISL£N, Vid.

Medd. Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 480.
Antedon brevipinna var. diadema HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 337 (description; Blake station 101). — A. H. CLARK, Unstalked crinoids of the Siboga-

Exped., 1918, p. 187 (referred to Crinometra). — GISL£N, Vid. Medd. Dansk Nat. Foren. K0ben-

havn, vol. 93, 1933, p. 481.
Antedon brevipinna var. pourtalesi HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 339 (Blake station 219), pi. 4, fig. 1.
Antedon brevipinna var. laevis HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323 (in

key), p. 343 (description; no locality), pi. 11, fig. 8. — A. H. CLARK, Unstalked crinoids of the

Siboga-Exped., 1918, p. 187 (referred to Crinometra).
Antedon brevipinna var. spinosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 343 (description; no locality), pi. 11, fig. 8. — A. H. CLARK, Unstalked crinoids of the

Siboga-Exped., 1918, p. 187 (referred to Crinometra).
Antedon brevipinna var. coronata HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 345 (description; Blake stations 241, 272, 219), pi. 11, fig. 7.— A. H. CLARK, Unstalked

crinoids of the Siboga-Exped., 1918, p. 187 (referred to Crinometra).
Antedon brevipinna var. ornata HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323 (in

key), p. 348 (description; Blake station 249), pi. 4, fig. 6, pi. 12, fig. 4. — A. H. CLARK, Unstalked

crinoids of the Siboga-Exped., 1918, p. 187 (referred to Crinometra).
Antedon brevipinna var. granulosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 351 (description; Blake station 45), pi. 11, figs. 1, 2. — A. H. CLARK, Unstalked crinoids

of the Siboga-Exped., 1918, p. 187 (referred to Crinometra).
Crinometra gracilis H. L. CLARK, Univ. Iowa Bull. Lab. Nat. Hist., vol. 7, No. 5, 1918, p. 10 (Bahama

Exped. station 2; notes).
Crinometra ornata H. L. CLARK, Univ. Iowa Bull. Lab. Nat. Hist., vol. 7, No. 5, 1918, p. 11 (Bahama

Exped. stations 9, 16; notes).
Crinometra coronata A. H. CLARK, Univ. Iowa Studies in Nat. Hist., vol. 9, No. 5, 1921, pp. 9, 11

(occurrence at Barbados; from Hartlaub).
Crinometra mortenseni A. H. CLARK, U. S. Nat. Mus. Bull. 82, vol. 1, pt. 2, 1921, figs. 535, 536

(pinnule tips), p. 287.
Crinometra granulifera A. H. CLARK, The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p.

40 (range). — GISL£N, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 481. — H. L.

CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, May 1941, p. 9 (Atlantis stations 2999,

3303, 3465, 3478, 3482).

Crinometra imbricata GISL£N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 22, 23.
Crinometra transversa GISL£N, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93, October 26, 1933,

p. 478 (description; comparisons; St. Helena, 280-360 meters, and ?480 meters), pi. 23, figs. 1-4,

?text fig. 5, p. 482. — GISL£N, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934,

p. 29.

A MONOGRAPH OF THE EXISTING CRINOIDS 283

Description. — The usual form of this species as it occurs off northern Cuba may
be described as follows: The centrodorsal is broad and discoidal with the broad dorsal
pole more or less stellate and studded with small tubercles; the sides show five more or
less pronounced interradial ridges. The cirrus sockets are arranged in 10-15 more or
less irregular columns, usually 2 or 3 to a column.

The cirri are XX-XXX, 15-19, about 30 mm. long. The first segment is short,
the second is about twice as broad as long, the third is about as long as broad, and the
fourth and fifth are about half again as long as broad; the following segments gradually
decrease in length, becoming distally about as long as broad. The third and one or
two of the following segments have a more or less prominent constriction in their
distal half, causing them to appear somewhat "dice-box shaped." The remaining
segments have a slight prominence of the distal ends and a strong dorsal overlap.
The dorsal profile of the distal half of the cirri is strongly serrate, although dorsal
spines are not developed. The distal dorsal edge of the segments is sometimes fur-
nished with a low ridge or a pair of low tubercles, one on each side. The opposing
spine is well developed. The terminal claw is about as long as the penultimate segment,
stout, and moderately curved.

The ends of the basal rays are visible as very irregular tubercles in the angles of
the calyx.

The radials and most, or even all, of the IB^ are concealed. The IBri when visible
are very short and bandlike. The IBr2 (axillaries) are low-triangular, two and one-half
to three times as broad as long. Both ossicles are thickly covered with a mass of very
irregular more or less confluent tubercles and blunt spines which often renders the
delimitation of the ossicles a matter of some difficulty. In the median line there is a
very irregular keel or a line of somewhat larger tubercles. The IIBr series are either
2 or 4(3+4), or both in varying proportions in the same individual. They have the
same ornamentation as the IBr series. IIIBr 2 series are usually present resembling
the IIBr series and developed internally in 1,2,2,1 order. The division series and first
three brachials are in close apposition and sharply flattened laterally.

The 15-30 (usually 21-30) arms are 120-160 mm. long. The first brachial has a
large median tubercle and a more or less tubercular dorsal surface. The second brachial
is somewhat less rough. The third brachial is smooth except for the median tubercle,
with the distal edge prominently everted and coarsely tubercular. The following
brachials as far as the tenth are similar but with the median tubercle less marked and
the coarsely tubercular character of the distal edge more accentuated. The first 10
brachials are oblong, about twice as broad as long, those following becoming wedge-
shaped, longer than broad, with the distal edges strongly overlapping and bluntly
serrate. After the proximal third of the arms the brachials become triangular, and
distally wedge-shaped again and somewhat elongate. The basal third of the arm is
somewhat compressed laterally.

Syzygies occur between brachials 3+4 (or 1+2, rarely 2 + 3, after a 4[3+4] series),
again in the vicinity of brachials 25+26, and distally at intervals of 6-14 (usually
about 8) muscular articulations.

PD (when present) is 12 mm. long with about 30 short compressed segments of
which the first six are about twice as broad as long and strongly flattened exteriorly

284 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and those following gradually become about as long as broad ; the edges of the segments
and more or less of the dorsal surface are studded with numerous fine spines. PI and
P2 are similar, 10-11 mm. long with about 21 segments of which the first two or three
are short, those following about as long as broad, and those in the outer half of the
pinnule elongate; the lower segments have roughened or more or less finely spinous
edges, and the distal are never more than twice as long as broad. These three pinnules
are moderately slender and taper gradually from the base to a slender and delicate tip.
PD is slightly larger than the others. PS is somewhat stouter than P2, especially in the
distal half, with about 18 segments of which the first three are short, the next three
about as long as broad and somewhat broadened, the remainder gradually tapering
and becoming elongate. The following pinnules to about Pj0 are similar but somewhat
shorter. The distal pinnules are about 8 mm. long with about 15 segments of which
the first is almost triangular, the second is irregularly trapezoidal, those following are
about as long as broad, becoming distally from half again to twice as long as broad.

The disk is completely covered with a pavement of small plates. The brachial
and pinnule ambulacra are bordered with well developed side and covering plates.
Sacculi are abundant, but small and inconspicuous.

The color hi alcohol is yellowish white, the division series and first three brachials
brown. Presumably in life the color is bright yellow with the division series and arm
bases brownish or olive.

Notes. — Although this description covers in a general way a large proportion of the
individuals that have been dredged in the Caribbean area, and especially about Cuba,
it is by no means adequate for the species as a whole, for this is perhaps the most
variable comatulid known. There is no fixed pattern in its ornamentation, which
varies from highly developed, coarsely tubercular or spinous, to completely absent;
in the form of the division series, which vary from almost flat, with or without water
pores, to strongly and evenly convex; in the composition of the division series, which
may be all 2 or all 4(3+4), or both in any combination; in the cirri, which vary from
short with short segments to more or less elongate with long segments ; in the pinnules ;
or in other features usually assumed to be reasonably constant in any single species.

Many of the forms are so very widely different from others — as angusta, gemmata,
and insculpta — that it seems at first sight impossible to regard them as representing
the same species; but they are all interconnected hi such a way that any attempt to
separate them specifically is wholly impracticable.

In his most excellent review of this species published in 1912 Dr. Clemens Hartlaub
said that the imposing number of fully, or at least almost fully, developed individuals
upon which he based his treatment of brevipinna in part bore specific determinations
in Carpenter's handwriting. In addition to these, he referred to brevipinna two speci-
mens which Carpenter had determined as representing a distinct species, pourtalesi.
The larger of the two Hartlaub regarded as the sole representative of Carpenter's
pourtalesi, referring the smaller to his new variety coronata.

He remarked that since the original description of brevipinna was based upon a
single juvenile specimen, it is naturally inadmissible as a diagnosis of the species, for
a diagnosis based upon a study of medium sized and large specimens would be entirely
different. A comprehensive account of the characteristics of the species seemed to him
scarcely possible, and in view of the variability of almost all the characters it seemed

A MONOGRAPH OF THE EXISTING CRtNOIDS 285

to him necessary, in order to portray the species adequately, to establish a large number
of varieties.

He emphasized the fact that in his attempt to determine the diagnostic characters
of the species his account is to be regarded as couched only in general terms and appli-
cable to the majority of, but not all, the individuals.

In his attempt to determine some of the characters of the species Hartlaub said
that the centrodorsal is often flat with a prominant incised dorsal pole, which is usually
ornamented. Interradial processes are present, but interradial ridges are rarety
developed.

The number of cirri is very different in the different varieties, ranging between
XV and XL. The number of cirrus segments varies from 12 to 20. The antepenulti-
mate segment bears an opposing spine. The cirri are relatively short.

The radials are not visible. The elements of the IBr series are usually flattened
dorsally. The IBr axillaries as a rule lack a proximalhr directed process. The IIBr
series are either 2 or 4(3+4). The ossicles from the IBr axillary to the fourth or fifth
brachial are in close lateral contact and sharply flattened laterally. The basal orna-
mentation, which is always different from the ornamentation of the arms, as well as
the darker color, if present, also does not extend beyond the fourth or fifth brachials.
There is often a striking lateral compression of the arms. In regard to the lower
brachials, a dual form is often conspicuously evident; the first few brachials (about 3)
are quadrangular, with parallel edges and right angles; these are followed by a few
(about 4) bluntly wedge-shaped brachials; then there are a few (usually 2) quadrangular
brachials; following these, often quite abruptly, are triangular brachials that persist
to the arm tips. Corresponding to the shape of the brachials, the articulations cross
the arm either transversely or diagonally.

The first syzygy is between brachials 1+2 or 3 + 4, and there may be a syzygy
in both positions so that an arm begins with two syzygial pairs. The position of the
following syzygies is inconstant in the same individual, and in different individuals
so very variable that this point must be considered in the accounts of the different
varieties.

The length of PD and of P! is very variable, according to Hartlaub, the size of the
individuals naturally playing a certain part in this. The length of PD varies between
8 and 17 mm., that of Pt between 6 and 12 mm. The number of segments in these
pinnules is also variable, though in this the size of a given variety seems not to play
a significant part. The number of segments in PD varies between 30 and 40, in PI
between 20 and 40; in P! there are usually 20-30 hi the individual varieties. The
segments of these pinnules are short, the basal always more or less singly or doubly
carinate. Generally speaking, the following pinnules decrease gradually in length
and in the number of their segments, in both these features attaining a certain degree
of uniformity in the middle of the arms. The pinnules in the middle of the arms are
3-7 mm. long with 7-13 segments of which the two first are, as a rule, short and broad
and the remainder elongate. Toward the ends of the arms in all the varieties the length
of the pinnules increases. When gonads are developed the few segments covering them
(about 3) are broadened. The anibulacral plating is always very prominent and con-
sists of side and covering plates.

The disk is usually flat and is often deeply incised.

286 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Hartlaub said that except for two specimens, representatives of the varieties
gracilis and diadema, the arms of alcoholic examples are never pure white, but grayish
or brownish white; the division series and arm bases are often darker colored.

According to Hartlaub, the best diagnostic feature of the species is the qualitative
as well as quantitative degree of development of the ornamentation. The ornamenta-
tion consists of tubercles, granules, teeth, or spines, or lips, or flanges, all appearing
in manifold forms and on various places on the ossicles. On the centrodorsal fine
ornamentation is found on the bare dorsal pole, between the cirri and also on their
first segments, and on the interradial processes. On the division series numerous varia-
tions in the occurrence of the ornamentation are to be seen. The ornamentation is
sometimes uniformly distributed over the surface of the ossicles, sometimes confined
to their borders, which are often crenulate or dentate, and sometimes confined to a
median ornament which may take the form of a ridge, a tubercle, or a row of tubercles.
The ornamentation of the arms is confined to the first 10-12 brachials, usually begin-
ning with the third and reaching to the tenth, twelfth, fifteenth, or twentieth. The
remainder of the arms is smooth. For the most part the ornamentation of the arms
is confined to the distal edge of the brachials which may be swollen and thickened,
or simply raised and erect, or turned proximally or recurved into a kind of lip; some-
times this modification of the distal edge is smooth, sometimes ornamented — tubercular,
dentate, or spiny. The ornamentation of the distal edges of the brachials appears
in numerous variations so that the differentiation of individual varieties is thereby
facilitated.

Hartlaub said that on the basis of the relative richness of the ornamentation, and
taking into consideration the type of branching of the postradial series, it is possible
to recognize definite varieties. He remarked it is evident that in the arrangement of
these varieties other attributes and aspects are also significant; he supplemented his
descriptions of the individual varieties by careful description of these features.

Among the specimens that Hartlaub assigned to bretnpinna he distinguished three
varietal types on the basis of the main ornamentation — that is, on the basis of the size
and number of ornaments each characteristically showed. These three types were:
(1) Tuberosa type, characterized by tubercular, humplike, knobby, or ridgelike
ornamentation — that is, blunt ornamentation ; (2) Spinosa type, characterized by spiny
or jagged ornamentation with pointed or sharp ends to the various processes; (3)
Granulosa type, represented only by a single variety characterized by granular, flat,
and rounded prominences. Hartlaub said it should be noticed that the forms of the
Spinosa and Granulosa types may be considered as transitions to granulifera, which he
considered as specifically different from brempinna; this point he discussed further
under the varieties concerned.

Hartlaub undertook to present a survey of the varieties of brempinna on the basis
of the ornamentation of the postradial series. But he pointed out that several of these
varieties were represented by a few specimens, or even by only a single one, so that
on the basis of the material available to him he was unable to say how constant they
are. He said that in this respect the best of all is var. insculpta ( = decora), represented
by 7 specimens, which appeared to him to be rather well characterized. In any case,
he said, it should be emphasized that the resolution of C. brevipinna into a series of

A MONOGRAPH OF THE EXISTING CRINOIDS 287

varieties is the only way to present a serviceable description for the recognition of such
varied specimens.

Hartlaub remarked that it would have been easy to make new species out of one,
or some, of the varieties, new species which would have been no more poorly based than
many established by Carpenter, as for instance, his pourtaUsi, but in view of the great
variability of almost all the characters he decided not to do this. He said that I had
already done this in part, as in December 1909 I had written him that his figure 1 on
plate 4 (Antedon brevipinna var. pourtaUsi from Blake station 219) is the same as my
Crinometra pulchra, and his figure 7 on the same plate (Antedon brevipinna var. elegans
from Blake station 193) is the same as my Crinometra coricinna.

Greater familiarity with the genus Crinometra has shown me the correctness of
Hartlaub's conclusions regarding C. brevipinna. Indeed, he did not go far enough.
The two specimens from Blake station 157 that he recorded and described under the
name of Antedon angusticalyx (=Perissometra angusticalyx) are in no way distinguisha-
ble from unornamented varieties of brevipinna with the IIBr series 4(3+4). These two
specimens are herein referred to brevipinna var. angusta, var. nov.

Hartlaub mentioned several specimens that seemed to him to be intermediate
between brevipinna and granulifera, which he regarded as a distinct species though he
failed to give its differential characters. Since he described granulifera (and angusticalyx)
in Carpenter's Qranulifera group and brevipinna in Carpenter's Spinifera group a natural
inference is that he considered granulifera to be characterized by having the IIBr series
4(3+4) while in brevipinna the IIBr series are 2. But in Crinometra this difference ia
of no significance. Indeed, in one of Pourtales' type specimens there are three IIBr 2
and two IIBr 4(3+4) series; in another all five IIBr series are 4(3+4) ; and in the third
the IIBr series are 4, with the two outer elements not united by syzygy. I am therefore
placing Pourtales' Antedon granulifera in the synonymy of brevipinna and referring to
brevipinna the two much broken specimens from Blake station 45 (the type locality of
granulifera), the two from Blake station 34, and the two from Martinique described
under granulifera by Hartlaub.

In the following pages there are recognized 19 varieties of Crinometra brevipinna.
Few, if any, of these represent fixed and stable types. All that are adequately known
are subject to more or less wide variation by which they approach, or intergrade with,
one or more other varieties.

It appears to be generally true that all or most of the individuals from a single
dredge haul during which there was no appreciable alteration of depth or temperature
will be very similar and will show certain features in common by which they differ from
those from other dredge hauls. In other words, they represent inbred family groups, or
groups showing a more or less definite correlation with their environment.

These recognized varieties vary in significance all the way from fairly well
characterized and stable types, like insculpta, gemmata, and pulchra to mere individual
variants some of which appear to be nothing more than undeveloped individuals of
more elaborately ornamented varieties. Much light will be shed on this subject when
the 288 specimens secured by the Atlantis in Cuban waters in 1938 and 1939 have been
studied.

The type specimen of brevipinna is a young individual with the varietal characters
not yet fully developed so that it cannot properly be allocated, and the specimens

288 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

described as brevipinna by Hartlaub are all similarly young and undeveloped. All that
can be said about them is that they appear to belong to at least two varieties.

It is by no means always possible to identify a given specimen with one or other of
these varieties, for it may be intermediate between two of them, or it may represent
another variety quite as good as some of those listed — which are merely those to which
names have been applied.

The 19 varieties of Crinometra brevipinna herein recognized fall into four types
which when typically developed are quite distinctive, but which intergrade to a greater
or lesser extent. These four types, with the included varieties listed roughly according
to the increasing specialization of their distinctive characters, are:

1. Pulchra type; division series and arm bases smooth, without ornamentation;
219-562 meters; temperature 15.33° C. (angusta, pulchra). The varieties angusta and
pulchra are probably only alternative forms of the same variety, with the IIBr series
either 4(3+4) (angusta) or 2 (pulchra).

2. Oranulosa type; ornamentation of the division series and arm bases consisting
of rounded or flattened granules, either confined to the borders of the ossicles or generally
distributee ; 185-475 meters; temperature 16.53° C. (granulifera, granulosa). The
varieties granulifera and granulosa are probably only alternative forms of the same
variety, with the IIBr series either 4(3 + 4) (granulifera) or 2 (granulosa).

3. Spinosa type; ornamentation of the division series and lower brachials consisting
of sharp conical spines or sharp dentations; 139-479 meters; temperature 8.33°-18.20° C.
(ornata, coronata, gemmata, spinosa) . The variety spinosa is probably only an alternative
form of the variety gemmata with the IIBr series 2 instead of 4(3+4).

4. Insculpta type; ornamentation of the division series and lower brachials con-
sisting of blunt tubercles, knobs, or more or less broad rounded ridges; 159-567 meters;
temperature 8.89°-16.67° C. (brevipinna, pourtalesi, diadema, margaritacea, tuberosa,
Iransversa, concinna, pulchella, gracilis, insculpta). This is Hartlaub's Tuberosa type
renamed so as to avoid confusion with Glyptometra tuberosa.

From the standpoint of the conditions hi the other genera in the family Charito-
metridae it appears most logical to regard the Pulchra type as the generalized stem
type from which the others have been derived, and within the Pulchra type the variety
angusta is more generalized than the variety pulchra.

The Pulchra type passes insensibly into the Granulosa type.

From the Granulosa type there are two lines of development; the granules may
elongate and become pointed, resulting hi an ornamentation or more or less stout conical
spines or dentations, such as characterize the Spinosa type; or the granules may become
enlarged and elongated into blunt tubercles or ridges with rounded crests, such as
characterize the Insculpta type.

In the family Charitometridae the IIBr series, when present, are usually 4(3+4),
or hi the majority of cases 4(3+4). In the Pulchra and Granulosa types IIBr series
of 4(3+4) and 2 seem to be equally common. In the Spinosa type one variety,
gemmata, has the IIBr series 4(3+4), the other three having the IIBr series 2. In the
Insculpta type the IIBr series are in all the varieties 2, though in some a few of them
may be 4(3+4).

The Insculpta type is an interesting parallel to the East Indian genus Glyptometra;
while the Spinosa type includes the only spiny forms hi the family Charitometridae,

A MONOGRAPH OF THE EXISTING CRINOIDS 289

a more or less similar development of spines being characteristic of many forms in the
allied family Thalassometridae.

The four varietal types in Crinometra brevipinna may be arranged in the order
of their presumed development as follows:

Pulchra type

Granulosa type

Spinosa type Inscnlpta type

The Insculpta type is much the commonest, and is the only type known to occur
at St. Helena. In the Caribbean area all the types appear to be generally distributed,
and on the basis of the meager data at present available there is no demonstrable differ-
ence in their bathymetrical and thermal relationships.

In the discussion of the several varieties the brief synonymy given is merely a key
to the references given in the full synonymy under the specific name.

Under the varieties only the localities from which each is definitely known are
given. The full data for these localities may be found by consulting the list of the
localities at the end of the account of the species. This full list of localities includes
many of the specimens that have not been allocated according to variety because
they are too young to have developed the characteristic varietal features, or for other
reasons.

KEY TO THE NAMED VARIETIES OF CRINOMETRA BREVIPINNA
a1. Division series and arm bases with more or less developed tubercular, granular, or spinous ornamen-

tation, at least along the borders of the ossicles.
6'. Ornamentation consisting of blunt tubercles, humps, knobs, rounded ridges, or granules, never

of spines.

c1. In addition to the chief ornamentation there are small tubercular, dentate, or spiny ex-
crescences, usually coalesced into lamellae, on the lateral borders of the division series and
first three brachials.

dl. The fine lateral excrescences are highly developed; the lateral borders of the ossicles as
far as the third brachial are strongly everted; median ornamentation of the ossicles of
the division series mostly knoblike ______________________________ insculpta (p. 291)

(P. The lateral excrescences are qualitatively and quantitatively less developed; the lateral
borders of the elements of the division series and first three brachials are only slightly
everted; median ornamentation of the ossicles of the division series more humplike.

gracilis (p. 296)

c1. No small excrescences on the lateral borders of the division series and lowest brachials.
<P. Lower brachials, beyond the arm bases, with thickened and usually produced and everted

distal ends.
«'. Lower brachials beyond the basal with greatly produced distal edges which are turned

proximally over the dorsal surface in the form of a lip.

/'. Proximally recurved liplike distal ends occur on the 5-10 brachials following the tenth;
from the third, eighth, or tenth brachial strongly thickened distal ends are developed
from the middle of which a smooth, of ten' quadrangular, swelling or broad tubercle
extends proximally downward over the dorsal surface.

g1. Entire surface of the elements of the division series thickly beset with equal sized
and uniformly distributed usually blunt tubercles of moderate size, which may be
coalesced; only exceptionally a larger shield-shaped median ornament.

pulchella (p. 297)

843803—60 - 20

290 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

g*. A large median tubercle or median ridge on the elements of the division series,

with small tubercles on the sides.

ft1. Beyond the IBr, only the borders of the elements of the division series carry small
tubercles; a larger median tubercle or median ridge always present.

concinna (p. 298)

ft3. In addition to the small tubercles, and beyond the always present large median
tubercle, there are larger ones on the elements of the division series, which give
the ornamentation a coarser character; there is no eversion of the distal ends;
dentation occurs only on the proximal border of the axillary, which may be

crenulate or pleated tuberosa (p. 303)

/*. Proximally recurved liplike distal ends are developed from the first to the fifth brachial
and onward; the fifth to eighteenth or twentieth brachials have raised tubercular
or almost dentate distal ends and a large knoblike median tubercle; from the ninth
to the thirteenth brachials the distal ends are recurved proximally without being

typically liplike diadema (p. 308)

«'. Lower brachials with only thickened, usually smooth, more rarely slightly crenulate

or tubercular, distal edges which are not produced and turned downward.
f1. Elements of the division series with strongly everted and more or less tubercular or
crenulate margins and an abrupt and conspicuous median ridge; cirrus segments

usually short, the longest half again as long as broad transversa (p. 301)

f1. Elements of the division series without prominently everted edges, with granular
or beadlike ornamentation often confined to the edges; cirrus segments usually
longer, the longest twice as long as broad.

01. Dorsal surface of the elements of the division series smooth, the lateral borders
only slightly tubercular; a row of small beadlike tubercles on the proximal border
of the IBr, and IBr axillary; IIBr 2.

hl. Elements of the IBr series with an elevated midline and a sharp median ridge.

brevipinna (p. 312)
fc*. Elements of the division series almost flat, with a low broad median swelling;

no median ridge pourtalesi (p. 309)

g3. Dorsal surface of the elements of the division series with more or fewer more or less

flattened granules or small tubercles.

hl. Dorsal surface of the division series with more or fewer large and more or less
flattened granules that become smaller and higher on the lower brachials;
usually a low and narrow median ridge.

t1. IIBr 2 granulosa (p. 325)

i*. IIBr 4(3 + 4) ..granulifera (p. 326)

h1. Dorsal surface of the division series evenly studded with more or less uniform
moderately large rounded or blunt tubercles which become gradually less marked
after the second brachial and disappear altogether at about the end of the
proximal fourth of the arm; elements of the IIBr and IIIBr series and first two
brachials with a low but prominent median carination continued on to the arms
in the shape of a prominent median tubercle on each brachial which disappears

at about the end of the proximal fourth of the arm margaritacea (p. 307)

d1. Arms from the third brachial outward entirely smooth, the brachials without thickened
distal edges; on the IBr axillary and the elements of the IIBr series the median ridge is
sharply produced, resulting in an angular sharpening of the dorsal surface, -laevis (p. 311)
V. Ornamentation consisting of sharp pointed spines or teeth.

c1. Ornamentation of the lower brachials and that of the division series equally well developed;
the whole surface of the division series and lower brachials as far as the tenth or twelfth
rather thickly and fairly evenly beset with spines or teeth.

<P. IIBr 4(3+4) gemmata (p. 318)

d>. IIBr 2-. spinosa (p. 316)

c1. Ornamentation of the arm bases qualitatively and quantitatively more strongly developed
than that of the division series.

A MONOGRAPH OF THE EXISTING CRINOIDS 291

d1 . Division series with fine marginal ornamentation in the form of small spines, tubercles, or
dentation; median ornamentation little developed; a row of spines or teeth on the distal

edge of the first ten or twelve brachials coronata (p. 320)

d*. Division series with coarse marginal ornamentation in the form of a coarse dentation;
median ornamentation strongly developed; distal border of the first 10 to 17 brachials
bristling with large spines and teeth, and the surface of the fourth-tenth brachials beset

with small spines or teeth ornata (p. 323)

a3. Division series and arm bases wholly without ornamentation, strongly convex or subcarinate
dorsally, the IBr axillary and the second segment beyond with more or less developed rounded
posterior processes.

6'. Brachials from the third or fourth to about the thirty-fifth with conspicuously swollen and
produced distal ends, the middle of which is swollen into a broad tubercle which may extend

anteriorly to the proximal edge; IIBr series 2 pulchra (p. 334)

V. Lower brachials without produced distal ends; IIBr series 4(3 + 4) .angusta (p. 335)

CRINOMETRA BHEVIPINNA nt. INSCULPTA A. H. Clark

PLATE 32, FIGURE 99
[See also vol. 1, pt. 2, figs. 680, 681, p. 338.1

Crinometra insculpta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 646 (description; Albatross
station 2753). — H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, 1941, p. 10 (Atlantis
stations 2950, 2980, 2980A, 2980B, 2982A, 2982B, 2982C, 2983, 2983A, 2984, 2987, 2999, 3000,
3303, 3326, 3372, 3388, 3425, 3430, 3431, 3432, 3434, 3435, 3436, 3438, 3466, 3467, 3478, 3482).

Antedon brevipinna var. decora HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in
key), p. 324 (description; Blake stations 34, 157, 158; also St. Vincent), pi. 11, figs. 4, 9.

Description. — The centrodorsal is flattened-hemispherical with the bare polar area
3 mm. in diameter, thickly covered with prominent small rounded tubercles. The
cirrus sockets are arranged in two, or two and a partial third, very closely crowded
and irregular rows.

The cirri are XX, 15-18, from 25 to 30 mm. long. The first segment is very
short, the second and third are about twice as broad as long, the fourth is about as long
as broad, the next four or five may be slightly longer than broad, and the remainder
are about as long as broad; or the fourth and following may all be about as long as
broad. The penultimate segment is twice as long as broad, slightly less in width than
those preceding. The opposing spine is minute, terminally situated, directly obliquely
forward. The terminal claw is about three-quarters the length of the penultimate
segment, moderately slender and moderately and evenly curved. The segments have
slightly thickened distal ends and the terminal six or seven have the distal part of the
dorsal surface raised into a transversely broad tubercle with a more or less crenulate
or serrate distal edge.

The ends of the basal rays are visible in the interradial angles as a cluster of high
tubercles, with difficulty separable from the similarly modified surface of the surround-
ing elements.

The radials are concealed. The IBri are very short, usually concealed except in
the angles of the calyx. The IBr2 (axillaries) are. triangular, three or four times as
broad as long. The IIBr series are 4(3+4) and 2, usually both in the same specimen,
the former in the majority; when the IIBr series are 2 the ossicles are in close apposition
along their entire lateral edges, no water pores being present. The IIIBr series are
2(1 + 2) following a IIBr 4(3+4) series, and 2 following a IIBr 2 series; they are devel-
oped internally. In the rare cases on which IIIBr series are developed externally they

292 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

are either 4(3+4) or 4(1+2, 3+4). The full complement of IIIBr series is never
present. The division series and lower brachials are slightly convex dorsally and are
laterally in close apposition and sharply flattened. The elements of the IBr series are
thickly and evenly covered with prominent tubercles resembling those on the dorsal
pole of the centrodorsal. These sometimes arrange themselves in a linear series hi the
median line, or there may be a more or less distinct median keel which, however, is
never well marked. This evenly tubercular ornamentation may encroach somewhat
upon the lower elements of the IIBr series, and always extends for a considerable dis-
tance up into the interradial angles and also between the IIBr series, narrowing to
a point distally. The elements of the IIBr and IIIBr series and the lower brachials
have more or less — usually strongly — crenulate or tubercular edges, and their dorsal
surface usually bears a few small scattered tubercles. Along the median line they bear
large and prominent dorsoventrally elongate, narrow, dorsally rounded tubercles which
form a conspicuous narrow carination.

The lower brachials have very strongly dentate or tubercular distal ends in the
center of which is a single large tubercle. These brachial tubercles form a median line
of tubercles along the arm that continues the carination of the division series out
along the arms, where it gradually dies away and disappears at about the end of the
proximal fourth. The prominent aversion of the distal edges of the brachials becomes
distally less strongly dentate, at the same tune becoming less and less erect, until at
about the twentieth brachial it becomes merely a moderately marked finely spinous
overlap and so continues to the end of the arms. The brachials as far as about the
twentieth are sharply flattened laterally.

PD is 13 mm. long, evenly tapering and becoming slender distally, with 30 segments
which at first are about three tunes as broad as long, becoming about as long as broad
distally; the first four or five segments are slightly carinate. Pt is 14 mm. long, slightly
more slender basally than PD, with slightly longer segments which become about one-
third again as long as broad distally; the lower segments are not carinate. P3 is 13 mm.
long. P3 is 12 mm. long. P4 is 11 mm. long, becoming progressively more expanded
basally but tapering evenly and very slender in the distal half. The pinnules following
still further decrease in length and increase in basal stoutness, P7 being 8 mm. long with
15 segments of which the third, fourth, and fifth are expanded, the fourth most so,
and the remainder are slender. For some time the pinnules are similar to P7, after
which they gradually lose the basal expansion and increase in length to 10 mm.

In alcohol the color is dull yellowish or light yellowish brown, the calyx and arm
bases to the third brachial often dark yellowish brown.

Notes. — A much more detailed description of this form is based upon one specimen
from St. Vincent without further data, one from Blake station 34, one from Blake
station 158, and four specimens and fragments of a fifth from Blake station 157, under
the name of Antedon brevipinna var. decora. The specimen from St. Vincent had an
arm length of about 85 mm. ; that from Blake station 34 an arm length of about 75 mm. ;
that from Blake station 158 an estimated arm length of 90 mm.; and the four from
Blake station 157 had arms 65, 75, 80, and 85 mm. long.

The centrodorsal is very flat. The bare dorsal pole is flat, sharply delimited,
bearing fine protuberances — small spines, tubercles, or teeth, in part isolated though as a
rule united into sinuous bands- — which are closely set and dark colored. Spiny and

A MONOGRAPH OF THE EXISTING CRINOIDS 293

tubercular protuberances are also found between the cirri, and on the interradial
processes which generally speaking are not especially produced. Here and there small
teeth and spines are found also on the first cirrus segments. The cirri are usually
arranged in pairs, one above the other.

The cirri are about XX, 14-18, always much lighter in color than the dark centro-
dorsal and division series. The two first segments are short, those following elongated;
the antepenultimate bears an opposing spine.

In ah1 the specimens the ornamentation of the bases of the postradial series is highly
developed and very uniform. Abundantly developed fine dentate protuberances,
mostly united into lamellae, cover the flat and more or less concealed IBn, and extend
distally along the everted lateral edges of the ossicles as far as the third brachial. In
proportion to the degree of their development, the lateral borders of these ossicles
acquire a more or less crinkled appearance. The ornamentation of the dorsal surface
of the ossicles is exceptionally developed. In addition to the protuberances mentioned,
which are distributed over its dorsal surface, the IBri usually bears a few white tubercles
among which a median tubercle is usually noticeable because of its greater size. The
IBr2 (axillaries) and the ossicles of the IIBr and IIIBr series bear on the dorsal surface
several light colored, often knoblike, tubercles and teeth which in part are coalesced
into swellings. In the median line there is a large tubercle, or several which together
may form a tubercular longitudinal ridge. On the IIBr axillary and on the IIIBr series
and first two brachials, the tubercles often move to the distal edge, which then appears
greatly produced. Otherwise the distal and proximal borders of these ossicles are not
conspicuously raised, but are usually beset with sharp teeth and spines which are
especially well developed at the articulations between the elements of the IBr series.
From the IBr axillary to the fourth brachial the ossicles are in very close lateral contact,
with sharply flattened sides. Like the centrodorsal, these ossicles are dark colored.

In all Hartlaub's specimens the radials are entirely concealed, and the mostly
concealed IBri are also noteworthy. The IBr2 (axillaries) are in general flat, more
rhombic than pentagonal. Hartlaub noted that the number of the elements in the IIBr
series is highly variable, not only in different specimens, but also in a single specimen.
Thus the largest specimen, from Blake station 157, has two IIBr 2 series and six IIBr
4(3 + 4) series, in one of which there is an uncommonly close union between the first
and second elements; two of the arms in this specimen arise from an IBr axillary.

In another specimen from the same station there are five IIBr 4(3+4) series and
three IIBr 2 series. In a third there is one IIBr 1 series (consisting of a single axillary
ossicle), four IIBr 2 series, and five IIBr 4(3+4) series. Both IIBr 2 and IIBr 4(3+4)
series occur together in the specimen from Blake station 158, and in that from Blake
station 34. In the specimen from St. Vincent all the IIBr series present are 4(3+4),
but one is missing; this specimen possesses both IIIBr 2 and IIIBr 4(3+4) series.

In all the specimens the proximal brachials bear an exceedingly characteristic
ornamentation. From about the third to about the fifteenth brachial the distal edges
are liplike, turned outward and downward. They are not smooth, but slightly tuber-
cular or somewhat pleated and markedly overlap the dorsal surface. At the syzygies
there are two similar lips close together.

The disposition of the syzygies is variable, on different arms of the same specimen
as well as in different specimens. The first two brachials may be united by syzygy or

294 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

by a muscular articulation; in either case there may be a syzygy between brachials 3+4,
more rarely between brachials 5 + 6. On one arm there are syzygies between both
brachials 3+4 and 5 + 6. The next syzygy, whether a second syzygy is present or not,
lies fairly constantly from about between brachials 13 + 14 to between brachials 20 + 21,
most commonly between brachials 15+16 or 16 + 17. The following intersyzygial inter-
val is from 4 to 14 muscular articulations, in most cases from 6 to 10.

Because of the regular presence of IIBr series the number of arms is as a rule 20,
but as the arms are often broken Hartlaub could not determine this with certainty.
Only the specimen from St. Vincent possesses more than 20 arms, and the largest from
Blake station 157 has only 18. The proximal brachials are rectangular and broader
than long; at about the fifth to the tenth the brachials become bluntly wedge-shaped,
and at about the middle of the arm their dorsal surface is approximately triangular.
The arms taper slowly distally.

The lowest pinnule on arms following the IBr axillary or a IIBr 2 series is Pt, on
postradial series with the IIBr 4(3+4) it is PD. PD is about 8 mm. long with 30 seg-
ments of which about the first ten are unusually thick, broad, and carinate, and on the
interradial side smooth hi correlation with the sharply flattened sides of the IIBr
series. The segments following are more slender and small. Here and there spines
or teeth are found on the edges of the segments. PD is dark colored as far as the dark
color extends on the postradial series. On the two arms arising from a IBr axillary
studied PI is somewhat longer than PD and is composed of 34 segments of which the
first ten are broad and flat; the pinnule tapers gradually; the fourth-seventh segments
have a strikingly strong single keel. On arms arising from a IIBr axillary P! differs from
the pinnule described. It is very variable in the form of the basal segments, not only
in different specimens, but strikingly so on different arms of the same specimen. For
instance, on the same postradial series one outer PI is 7 mm. long and has six broad
proximal segments which in surface view appear heartshaped or approximately triangu-
lar with proximally directed points; a carination is scarcely suggested. The other outer
P! is 6 mm. long with 10 much broader proximal segments of which the form is more
quadrangular; its most striking feature is a typical double keel; the crests of the keels
as far as the fifth segment on one side, thence on both sides, are beset with spines and
teeth, or serrate. The small distal segments of the two pinnules are also different.
Neither pinnule follows a PD so that their positions are entirely comparable. Only
in the majority of cases can the following be said of P!. It is composed usually of 20-25
segments of which the 8-10 proximal, with the exception of the first, are doubly keeled,
the crest of the carination being spiny or serrate on one or on both sides. The proximal
segments are more closely united than in PD, in which they follow each other rather
closely. The small distal segments are sometimes more triangular, sometimes more
rectangular. Proximally rather broad, PI tapers only gradually to a fine point. P.
and P2 are in general snorter than PI, usually 5-7 mm. long with 16-23 segments of
which the edges are in part dentate or spiny. But there is marked variation in the
length and in the number of included segments. The number of segments may vary
as much as 10 in the same specimen, as for instance in the largest specimen from Blake
station 157 in which Pa has from 17 to 27 segments. In the same specimen one P2 is
over 10 mm. long with about 35 segments and of the same length as PI on the same arm.
In the specimen from Blake station 158 one P8 is barely 3 mm. long with 10 segments.

A MONOGRAPH OF THE EXISTING CRINOIDS 295

In the same specimen P£ on another arm is abnormally short — 3 mm. long with only 11
segments — shorter than P3 of the same arm, which is 5 mm. long with 16 segments. The
form of the broader proximal segments of Pa and Pj varies, even hi the same specimen.
Sometimes the second-sixth segments are more triangular, sometimes more quadrangu-
lar. On some P2 the third and fourth, or in addition the second and third, segments
of one side have an especially long keel, a feature which in other pinnules of the same
type is not evident. Pb and P3 are generally somewhat shorter, 5-6 mm. long with
14-16 segments, and about 6 broad proximal segments of which the second-fourth or
second-sixth are singly or doubly carinate, and the 8-10 outer are elongate and small;
the crest of the keels may be either smooth or dentate. The pinnules following — Pe,
P4, and Pa — are on the average shorter, about 4-5 mm. long with 10-13 segments; in
the form of the basal segments, in the number of their segments, and in their length,
they form a transition to the pinnules of the brachials succeeding and the middle of the
arm, up to about the fifteenth brachial. These pinnules are short; almost always two
thick and broad basal segments may be recognized, followed by 7-10 elongated ones.
This type of pinnule can be shown to be typical for the middle of the arm hi all the speci-
mens. Preponderating by far are pinnules 3 mm., seldom 4 mm., long with 9 segments;
variants are pinnules with three broad basal segments, and others 5 mm. long with 1 1-12
segments. Toward the arm tips there appears to be no increase in the length of the
pinnules, but because of the poor state of preservation of the arm tips Hartlaub was
unable to make a definite statement in regard to this.

The ambulacral plating of the pinnules consists of well developed side- and covering-
plates. The sacculi are rather small and inconspicuous. The disk is deeply incised,
8-10 mm. in diameter, brown in color.

In alcohol the centrodorsal and post-radial series as far as the third brachial are
dark — -brownish to brown — -with the remaining brachials and the cirri white.

Localities. — -Blake stations 34, 157, 158, also St. Vincent; Albatross stations 2161,
2752, 2753; Atlantis stations 2950, 2980, 2980A, 2980B, 2982A, 2982B, 2982C, 2983,
2983A, 2984, 2987, 2999, 3000, 3303, 3326, 3372, 3388, 3425, 3430, 3431, 3432, 3434,
3435, 3436, 3438, 3466, 3467, 3478, 3482 ; off St. Croix. For the details of these stations
see page 339.

Geographical range. — From the Yucatan Bank, Cuba, and the southern Bahamas
southward along the Antillean chain to St. Vincent.

Bathymetrical range. — From 267 to 548 meters.

Thermal range. — One record, 8.89° C.

Remarks. — Dr. H. L. Clark recorded 272 specimens of this form from the Atlantis
stations given. It seems unlikely that all of these really belong to it; some of the other
related forms surely should be represented in such extensive material. A detailed
study of the Atlantis specimens is much to be desired.

Dr. Clark said that several of the specimens were still attached to the sponges
upon which they apparently often live. Most of them still retained some trace of a
bright yellow color which is very marked in many specimens and was apparently the
normal color in life; in large specimens the calyx and base of the arms is darker and
duller, an indistinctive gray-brown. Dry material is often more or less bleached,
sometimes nearly white. The size of the specimens ranged from about 8-10 mm.
across the disk, with arms 50 mm. long, more or less, to big adults 20-25 mm. across

296 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

the disk with arms nearly or quite 200 mm. long. He said that there is no little diver-
sity in the sculpturing and ornamentation of the calyx and arm bases, but on the whole
the species characters (of insculpta) are well maintained.

CRINOMETRA BREVIPINNA Tar. GRACIUS (Hartlaub)

Antedon brevipinna var. gracilis HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322
(in key), p. 328 (description; Blake station 157), pi. 12, fig. 3.

Description. — 'This variety was described from a single specimen with the arms
about 75 mm. long from Blake station 157.

Hartlaub said that at first sight this specimen is noteworthy by its slender habitus
resulting from its long, narrow, and laterally compressed arms. There is no darkening
of the centrodorsal and the postradial series. Except for the somewhat darker deeply
incised disk it is, in alcohol, of a brilliant white color.

Its significant differences from var. insculpta (decora) are as follows. The very
flat centrodorsal has fewer cirri with few segments, the cirri being XVI, about 12; the
penultimate segment bears an opposing spine.

The fine lamellaelike protuberances are qualitatively and quantitatively less
developed on the centrodorsal and on the only slightly everted lateral borders of the
ossicles of the division series and first four brachials; similarly, the number of the
tubercles or swellings on the division series and lower brachials is small; in contrast to
var. insculpta (decora), there are here broad and large lumps and swellings. As a
result, the division series have a far less rough appearance. The lips on the lower
brachials are finer.

All the IIBr series are 2, and there is one IIIBr 2(1+2) series so that the number
of arms is 21. Almost throughout, the first syzygy is between brachials 1+2 and the
second between brachials 3+4, so that the arms begin with two syzygial pairs, except
for the two arms arising from the IIIBr axillary in which the first syzygies are between
brachials 5 + 6 and 8+9. In marked contrast to this is the sequence of syzygies in
arms arising from the IIBr axillaries. The next syzygy is from between brachials
11 + 12 to between brachials 13+14, most commonly by far between brachials 12+13;
the next is from between brachials 17+ 18 to between braclrals 20 + 21, usually between
brach-als 19 + 20, and those succeed'ng follow most commonly at 'ntervals of 5, 6, and
7, very rarely 8 and 10, muscular art;culat;ons. Thus the syzygies are characteristi-
cally close together.

PI is 6 mm. long with 20 segments of which usually only 4 and at the most 6 of
the basal are broadened, with fully double or more strongly single keels. The pinnules
succeeding, gradually decreasing from 5 to 4 and to 3 mm. in length to the eighth
brachial, have moderately broadened proximal segments which are followed by elongate
ones. The pinnules of the middle portion of the arms are about 3 mm. long with,
as a rule, 10 segments of which the first two are short and the first is markedly broadened.

The ambulacral plating consists of side and covering plates. The sacculi are
small and inconspicuous.

Locality. — Blake station 157.

Geographical range. — Known only from off Montserrat, British West Indies.

Bathymetrical range. — -Recorded only from 219 meters.

A MONOGRAPH OF THE EXISTING CRINOIDS 297

CRINOMETRA BREVIPINNA var. PULCHELLA. var. nor.

Antedon brevipinna var. pulchra (not Crinometra pulchra A. H. Clark, 1909) HARTLAUB, Mem. Mus.
Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in key), p. 329 (description; no locality; Blake).

Description. — Hartlaub regarded a very large specimen with rather slender and
laterally compressed arms reaching about 150 mm. in length as a representative of a
special variety. Unfortunately there was no locality label with it.

This variety differs from var. gracilis externally by its stouter habitus and the
dark color of its centrodorsal which in places is almost black, and by the exceptionally
light cirri and division series. The upper border of this dark color is very different on
the several postradial series.

The form of the centrodorsal resembles that described for var. insculpta (decora).
So does the ornamentation, which is composed of fine pointed protuberances coalesced
into lamellae on the dorsal pole and on the sides of the centrodorsal. In contrast to
var. insculpta and var. gracilis, these are confined to the centrodorsal.

The cirri are XXIV, all broken off beyond a few basal segments.

The ornamentation of the ossicles of the division series consists of uniformly large
usually blunt tubercles which, closely placed and occasionally coalescing, rather uni-
formly cover the ossicles. Only very exceptionally is there a larger median tubercle
or a median ridge. In contrast to var. insculpta the proximal, distal, and lateral borders
of the segments are not distinguished by special ornamentation. On the surface of the
ossicles of the IIIBr series and first four brachials there is found, in contrast to var.
insculpta, a broader shield-shaped swelling or tubercle, besides which there are the
small tubercles of the type found on the IBr and IIBr series. These last generally end
at the fourth brachial. The radials are not visible. All the IIBr series are 2 and, like
the IBr series, are flat. All the axillaries are rhombic. There is one IIIBr 2 series.

There are 21 arms. The ornamentation of the brachials from the third outward to
about the tenth differs from that characteristic of var. insculpta and var. gracilis in
that a larger, smoother, and approximately quadrangular tubercle or swelling arises
from the lower edge of the swollen distal border of the brachials in the middle of their
dorsal surface. As far as about the tenth brachial the form of the rather flat ossicles
is rectangular with transverse articulations. After the tenth the brachials assume a
more diagonal direction, the brachials rather suddenly becoming approximately tri-
angular and longer and at the same time developing a liplike ornamentation, the median
tubercles disappearing and the produced and slightly crenulate or tubercular distal
edge being turned downward in the middle.

In contrast to var. insculpta and var. gracilis, there is never a syzygy between
brachials 1 + 2. The first syzygy is usually between brachials 3 + 4, very rarely
between brachials 4 + 5. In the two arms arising from the IIIBr series the first
syzygy is between brachials 18+19 and 27+28. The syzygy between brachials 3 + 4
is followed very rarely by one between brachials 6 + 7; as a rule the second syzygy, as
in var. insculpta, is from between brachials 12+13 to between brachials 21+22; the
next occurs after an interval of from 8 to 11, usually 8, muscular articulations, and the
distal intersyzygial interval is from 6 to 13, usually 7-9, muscular articulations.

P! is about 10 mm. long with 25-30 segments of which the first 5 or 6 are markedly
broadened and narrowly carinate on both sides. The pinnules following as far as P4
are somewhat — about 1 mm. — shorter with about 20 segments of which only 4, or 3,

298 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

are broadened and doubly carinate. Here and there the edges of the segments are
beset with teeth and spines. The pinnules of the middle of the arm, from about the
thirty-fifth brachial onward, are about 7 mm. long with 15-17 segments of which the
two basal are short and broad, those following elongate. In contrast to the middle
pinnules of var. insculpta, from which they differ sharply in the greater number of seg-
ments, they are entirely smooth, as the distal ends of the segments are not produced.
Toward the arm tips the length of the pinnules seems to increase somewhat. Wherever
gonads are developed on the pinnules, as on P3, the two or three segments covering them
are markedly broadened.

The ambulacral plating consists of prominent side and covering plates. Sacculi
are of medium size and inconspicuous. The disk is as deeply incised as that of var.
insculpta.

Locality. — West Indies.

CRINOMETRA BREVIPINNA var. CONCINNA A. H. Clark

[See vol. 1, pt. 1, figs. 206, p. 239, 276, p. 260, 492, p. 367; pt. 2, figs. 76, 77, p. 53, 302, p. 223, 678,

p. 338.]

Crinomelra concinna A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 646 (description; Albatross

station 2342).
Antedon brevipinna var. elegans HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in

key), p. 331 (description; Blake station 193), pi. 4, fig. 7, pi. 11, fig. 5.
Crinometra gracilis H. L. CLARK, Univ. Iowa Bull. Lab. Nat. Hist., vol. 7, No. 5, 1918, p. 10 (Bahama

Expedition station 2).

Description. — The centrodorsal is a flattened hemisphere with the bare polar
area 3 mm. in diameter and thickly beset with long tubercles. The cirrus sockets
are arranged approximately in 10 crowded columns, two or three to a column, the
columns sometimes separated by strongly tubercular ridges.

The cirri are XX, 14-18 (usually 15 or 16), from 25 to 30 mm. long. The first
segment is very short, the second and third are about twice as broad as long, the fourth
is nearly or quite as long as broad, and the remainder are about one-third again as
long as broad, becoming slightly shorter distally; the antepenultimate segment is
longer than those preceding, half again as long as broad, and the penultimate segment
is about twice as long as broad, its width being somewhat less than that of those pre-
ceding. The cirrus segments have their distal ends somewhat enlarged and slightly
overlapping, this feature being most marked on the dorsal side of the outer half of the
cirri. The opposing spine is minute, terminally situated, and directed obliquely
forward. The terminal claw is not so long as the penultimate segment, stout basally
but rapidly tapering distally, moderately curved.

The ends of the basal rays are visible in the angles of the calyx; they bear one or
more long tubercles.

The radials are concealed. The IBri are very short, often more or less concealed
by the centrodorsal, bandlike and curved or narrowly crescentic. The IBr2 (axillaries)
vary from rhombic to approximately triangular, and are two-and-one-half times as
broad as long; their lateral borders are as long as those of the IBr, and are often, like
them, reduced to a point. The IIBr series are usually 2; in eight specimens one IIBr
series is 4(3+4), and two are 4, the ossicles united in two synarthrial pairs. The
IIIBr series are 2, developed interiorly in 1, 2, 2, 1 order. The edges of the ossicles

A MONOGRAPH OF THE EXISTING CRINOIDS 299

as far as the third brachial are everted and raised, usually broken up into high blunt
tubercles which are more or less confluent with similar high and blunt and also more
or less confluent tubercles on the dorsal surface. The IIBr and IIIBr series and first
two brachials usually have a high and rather narrow median ridge, which is higher
than the tubercles on the dorsal surface; this is sometimes partially or entirely broken
up into two or three dorsoventrally elongate tubercles which are larger than any
others on the ossicles. The proximal edge of the axillaries and the inner proximal
edge of the second brachial are curved upward, while the distal lateral angles of the
ossicles preceding the axillaries, and the inner distal angle of the first brachial, are cut
away leaving prominent openings serving as water pores. The division series are
only slightly convex dorsally, and are in very close lateral apposition.

The 30 arms are 150 mm. long and resemble those of the other forms of the species.
The lower brachials to about the fifteenth have strongly everted distal ends which
are usually more or less crenulate or tubercular. There is usually a prominent median
dorsoventrally elongated tubercle, and usually also some more or less obsolete tubercles
on the dorsal surface. From the fifteenth onward the brachials are almost perfectly
smooth dorsally. The first sixteen brachials are sharply flattened laterally.

The pinnules are essentially like those of the other forms.

The disk is completely covered with a pavement of very small rounded plates.
There are well developed side and covering plates along the pinnule ambulacra.

The color in alcohol is yellowish white, with the calyx, division series, and arm
bases as far as the third brachial brownish.

Notes. — A large specimen with the arms about 140 mm. long from Blake station
193 differed in so many respects from var. insculpta, (decora), var. gracilis, and var.
pulchella (pulchra) that Hartlaub considered it best to regard it as the type of a special
variety.

The centrodorsal, of which the dorsal pole is blackish brown, and the division
series and arm bases as far as the third or fourth brachial are dark in color. The arms
and cirri are in general lighter, though some arms are dark as far as the middle and
beyond.

In contrast to var. insculpta (decora) the centrodorsal is hemispherical and rather
high, and it is further distinguished by prominent interradial ridges and processes.
The bare dorsal pole shows a deep, circular, almost black central cavity the edge of
which is beset with teeth, which also occur on the first segment of the adjacent cirri.
There is no further ornamentation on the centrodorsal.

Subradial clefts are present.

The radials are entirely concealed. The whole basal ornamentation, including
that of the centrodorsal, entirely lacks the finer protuberances, mostly united into lamel-
lae. The ornamentation of the IBr and IIBr series and in part also of the IIIBr
series or the first two brachials shows a characteristic feature in that the borders of the
individual ossicles are delimited by a row of small light-colored tubercles, resulting in
part in a typical dentation. Besides this, there- is on all the ossicles a large median
tubercle or median ridge. The lateral borders of the ossicles from the IBr axillaries
to the second brachials are somewhat everted and beset with light tubercles, here and
there typically dentate; with the exception of the very flat IBr! which is entirely covered

300 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

with tubercles, often gathered into groups of several, there are no tubercles on the
smooth dorsal surface of the IBr and IIBr series. From the IBrt to the fifth brachial
the ossicles have sharply flattened sides. Noteworthy is the everted proximal border
of the rhombic IBr axillary. Of the IIBr series, nine are 2 and one is 4(3+4); the
IIBr series are 2.

There are 22 arms. The ornamentation of the arms from the fourth to the eighth
or tenth brachial, and the form of the brachials, resemble the same features in var.
pulchella. At about the twelfth brachial the swellings or tubercles stop and liplike
ornamentation begins, coincident with the transition of the brachials to a triangular
form with diagonal articulations. After the end of the liplike ornamentation, which
runs to about the twentieth brachial, the next 10-15, or thereabouts, brachials carry a
blunt tubercle on the distal border which was noticed by Hartlaub in other varieties,
but in them it is not so prominent, nor does it appear on so many brachials. At about
the fiftieth brachial the triangular form passes over into a bluntly wedge-shaped form.

The sequence of the syzygies is rather variable and resembles that in var. insculpta.
On arms arising from a IIBr axillary the first syzygy is always between brachials 3+4;
the second is from between brachials 6 + 7 to between brachials 16+17, and the distal
intersyzygial interval is from 5 to 10 muscular articulations. In the four arms arising
from IIIBr axillaries the first syzygy is between brachials 1+2; this is followed by
another between brachials 3+4 or 4 + 5; the next is from between brachials 12 + 13 to
between brachials 16 + 17; and the distal intersyzygial interval is from 6 to 8 muscular
articulations. In the two arms following the IIBr 4(3 + 4) axillary the first syzygy is
between brachials 1+2; on one arm there is another between brachials 5+6; the next
syzygy is between brachials 11 + 12 on one arm and between brachials 12 + 13 on the
other; the following syzygy is between brachials 22+23, and the distal intersyzygial
interval is from 4 to 9, usually 6 or 7, muscular articulations.

P! is 10-12 mm. long with about 40 segments — the largest number found in any
of the varieties of Crinometra brevipinna. The 6-8 basal segments are broadened and,
with the exception of the first, doubly carinate, a narrow keel being especially promi-
nent on one side of the second-fourth segments. These broadened segments are fol-
lowed by small elongated segments which toward the pinnule tips become short again
and often also broader. The pinnules following to about P4 are 9-1 1 mm. long and have
a smaller number of segments. On some arms they are as long as Pb on others 1-2
mm. shorter; the second to fourth segments have a narrow keel on one side. From this
point onward the pinnules gradually become shorter. The pinnules of the middle
of the arm, from about the twenty-fifth brachial onward, are 7 mm. long with usually
13 segments of which the two or three basal are short. Beyond the fiftieth brachial
the length and number of segments again increases. The distal pinnules are 9 mm.
long with about 16-18 segments. Most of the pinnules from P3 onward bear short
gonads the two or three segments covering which are broadened.

Especially striking are the dark colored sacculi; the side- and covering-plates are
easily visible to the naked eye.

The disk is 1 1 mm. in diameter and slightly incised, as in var. insculpta.

Localities. — Blake station 193; Albatross station 2342; University of Iowa's Bahama
Expedition station 2.

Geographical range. — From northern Cuba to Martinique.

A MONOGRAPH OF THE EXISTING CRINOIDS 301

Bathymetrical range. — From 201 to 367 meters.
Thermal range. — One record, 10.56° C.

CRINOMETRA BREVIP1NNA var. TRANSVERSA Gialfin

Crinometra transversa GISLEN, Vid. Medd. Dansk Nat. Foren. K0benhavn, vol. 93, 1933, p. 478, fig.
5 (?), p. 482, pi. 23, figs. 1-4; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934,
p. 29.

Description. — The ceiitrodorsal is a thick disk, considerably excavated at the
dorsal pole, which is 3 mm. in diameter, granulated and pitted; the interradial portions
are covered with stout pointed tubercles. The cirri are arranged in 15-20 crowded
columns.

The cirri are XXXVI, 17-18, about 23 mm. long. The first three segments are
short, the fourth is as long as broad, the fifth is half again as long as broad, the sixth is
one-third again as long as broad, and the eighth is as long as broad. From the eighth
segment onward there is a dorsal projection which from the ninth to the twelfth is
transformed into a transverse, indistinctly bilobate, crest. The opposing spine is
similarly transverse, with sometimes a slight notch in the crest. The terminal claw
is slightly shorter than the segment preceding, which is one-third again as long as broad.

The radials are scarcely visible except in the interradial angles where there are
some projecting tubercles. The IBri are very short, covered with long tubercles which
proximally and distally fuse into serrate flanges along the borders of the ossicle. The
IBr3 (axillaries) have a high mediodorsal tubercle and the flanged proximal and distal
borders are provided with three or four stout eminences on each side of the median
line both proximally and distally. In this way the margins of the ossicle are bordered
by a more or less distinct and everted denticulation; moreover, there is a median dorsal
tubercle or crest; otherwise, however, the ossicle is smooth. A crest, well set off, also
appears on the first two elements of the IIBr series, which have generally everted mar-
gins and sometimes also marginal tubercles. Of the 10 IIBr series, 9 are 2 and one is
4(3 + 4). The IIIBr series, which are internally developed, are 2.

The 24 arms are 150 mm. long. The first two brachials have a mediodorsal knob
and on some arms also slightly everted margins. On the third and fourth brachials
there may appear some extra submedian knobs. The median tubercle is later trans-
formed into a dorsal spine or carination which is developed in the distal portion of the
ossicle. This tubercle is traceable only a short way along the arm. The distal margin
of the brachials soon becomes a little overlapping and more or less denticulate. Though
in rather close lateral contact basally, the arm bases are only slightly, or not at all,
"wall-sided."

Syzygies occur between brachials 1+2, again from between brachials 16+17 to
between brachials 20+21, and distally at intervals of from 2 to 17 (usually about 10)
muscular articulations.

PI is about 13 mm. long with 27-28 segments. P2 is 14 mm. long with 24 segments.
P4 is 12 mm. long with 19 segments. Ps is about 9 mm. long. Pg is 9 mm. long with
15 segments. P13 is 9 mm. long with 15 segments. The distal pinnules are a little
longer again; the proximal segments are short, the distal one-third again as long as
broad, as in the proximal pinnules. From about P5 onward the third-fifth segments
are somewhat expanded.

302 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The disk, which has been thrown off, is closely granulated with small calcareous
granules.

The color is yellowish, except in some of the basal arm parts where it is blackish
usually as far as the first brachial.

Notes. — In a second specimen the centrodorsal is flattened dorsally with the free
dorsal surface closely pitted. There are rather high interradial crests. There are 20
cirrus sockets, arranged in 10 groups. The cirri have been thrown off.

The IBr axillaries have a well-marked median crest and one or two submedian
tubercles, and their borders are a little everted. There is a high keel also on the first
two elements of the IIBr series. The ossicles following are provided with high rounded
median knobs. Of the 9 IIBr series 7 are 4(3+4) and 2 are 2; there is a single IIIBr
2 series. The carination of the division series and arm bases is much less marked than
in the specimen first described, especially on the IBri, which is clearly visible; its margins
are a little everted, but the tubercles are rather insignificant.

The 21 arms are 60 mm. long. There is a high keel on the first two brachials.
The brachials following are provided with high rounded median knobs.

The proximal syzygies are usually between brachials 1+2 after a IIBr 4(3+4)
axillary, after a IIBr 2 axillary either between brachials 3 + 4 or between brachials
1+2 and 3 + 4.

PD is about 9 mm. long with about 20 segments. The distal pinnules are 5 mm.
long with about 10 segments.

The arm bases are dark colored. Arms regenerating from the first or third bra-
chials are yellowish.

Gisl6n said that as to the arm sculpture Crinometm transversa resembles some of
Hartlaub's brevipinna varieties, decora (=insculpta) , gracilis, and tuberosa, and my
insculpta. But the middle pinnules of the arms are proportionately longer than in
most of the other Crinometras; the wall-sidedness of the basal arm parts and the cari-
nation of the proximal pinnules are not at all or only slightly developed. The mediodorsal
carina of the basal arm parts is more sharply set off than in any of the forms described
earlier. But above all, the transverse crest of the cirrus segments distinguishes trans-
versa at once from all the Crinometras so far described.

There is no tangible difference between transversa and some of the forms of the
Insculpta type of Crinometra brevipinna. In certain of these forms the middle pinnules
are as long as they are in transversa, the carination of the lower pinnules is only
slightly developed, and the distal dorsal end of the cirrus segments, which are as short
as in transversa, bears a low transverse ridge or a pair of low tubercles (see page 291).
This last feature, however, was not known to Professor Gisle'n, since at the time he
wrote no detailed description of the cirri of any of these varieties had been published.

As there is no single character or group of characters by which transversa may be
distinguished from certain varieties of the Insculpta type, I am considering transversa
as a variety of brevipinna, finding its proper place in the Insculpta type.

The significance of the occurrence of a form of Crinometra brevipinna at St. Helena
is emphasized by the unrecorded occurrence of the remarkable Moiraster magnificus
(Bell), heretofore known only from St. Helena, off Puerto Rico. The U. S. National
Museum possesses a remarkably fine specimen with R=168 mm., r=43 mm. from

A MONOGRAPH OF THE EXISTING CRINOIDS 303

Caroline station 35, off the west coast of Puerto Rico (lat. 18°24'45" N., long. 67°14'15"
W.), in 146-329 meters.

Pentacrinoid. — A pentacrinoid larva referred to this species by Professor Gisl£n
is about 3.4 m. long. The calyx is composed chiefly of orals and basals. Small radials
appear hi the angles between the orals and basals. The orals have everted lateral
borders. There are 9 columnals, including the terminal stem plate. The two first
columnals are short, the second being wider than the stem. The third and fourth,
according to GislSn, are apparently double; they are from half again to twice as long
as broad. The fifth and sixth are very long, from three to four times as long as broad.
The seventh is much shorter, and the eighth is one-third again as long as broad. The
ninth is a short disk attached to a dead Lophohelia,.

Professor Gisl6n said that as no comatulid except Crinometra transversa is known
from this depth in the vicinity of St. Helena this pentacrinoid may be the larva of this
form; though the possibility of a species of the family Thalassometridae occurring here
cannot be denied.

Localities.— Off St. Helena; 2 miles S. 49° E. from Long Range Point; 280-360
meters; hard bottom; Dana, February 24, 1930 [Gislen, 1933].

St. Helena; 2 miles off Bay Point; 480 meters; Dana, February 24, 1930 [Gislen,
1933]. The pentacrinoid larva came from this locality.

History. — This variety was described and figured by Prof. Torsten Gislen in 1933
from a specimen that had been dredged by the Danish research steamer Dana in 1930
and sent him by Dr. Th. Mortensen. He gave notes on another specimen taken with
the type specimen, and described and figured a pentacrinoid which he referred to this
species.

CRINOMETRA BREVIPINNA Tar. TUBEROSA (Harllaub)

Anledon brevipinna var. tuberosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322
(in key), p. 333 (description; Blake stations 198, 219; no locality), pi. 11, fig. 3.

Description. — Hartlaub referred to this variety three specimens without locality,
one from Blake station 219, and one from Blake station 198. The three specimens
without locality are of similar size with the arms about 125 mm. long; the specimen
from Blake station 219 is similar to these, but stouter; that from Blake station 198 has
the arms about 115 mm. long. The three without locality agree perfectly in all their
characters and are remarkable for the small calyx and long and slender arms — about
120 mm. long from the last axillary.

In all five specimens the contrasting coloration seen in var. pvlchella and var.
concinna (elegans] is absent. In general they are light in color. The centrodorsal and
a few ossicles of the division series are only here and there more darkly colored.

In all five the ornamentation of the division series shows larger and smaller, some-
times sharp, sometimes blunt tubercles which are distributed without special affinity
to the borders of the ossicles, in contrast to the conditions seen in var. concinna, although
here and there, especially on the edges of the axillaries, there may be a typical serration.
Noteworthy is the regular presence of a median tubercle of varied form, or a medium
ridge, and hi addition the production of the dentate, serrate, or crenulate proximal
border of the rhombic IBr axillary.

In contrast to var. pvlchella and var. concinna, the tubercles are larger, giving the
general ornamentation of the division series a coarser character. Between the cirri

304 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and on the interradial processes the centrodorsal has a few small tubercles or teeth
which become somewhat larger and more numerous on the bare dorsal pole. The
smaller tubercles run outward as far as the second or third brachials. On the first three
brachials beyond these there is one, or on syzygial pairs two, median tubercles or humps,
this variety in this respect quite resembling var. pulchella and var. concinna. The five
specimens of var. tuberosa also agree essentially with these varieties in the ornamenta-
tion of the brachials following, from the third to about the sixth, eighth, or tenth.

In the specimen from Blake station 198 the tubercle in the middle of the brachials
is not so large as it is in var. pulchella and in var. concinna; this specimen also has more
rectangular lower brachials than the others in which diagonal articulations occur after
the third brachial. All five specimens first show typical triangular brachials after about
the tenth. On many arms at the same time or somewhat earlier or later, the more or
less crenulate and everted distal ends appear in typical liplike form. These liplike
eversions appear prominently as in var. pulchella and in var. concinna only on a few of
the following brachials — on from four to eight — then gradually become smaller, dis-
appearing slightly beyond the elevated tubercles on the dorsal surface of the brachials.
Toward the arm tips the triangular form of the brachials passes over into a bluntly
wedge-shaped form.

Hartlaub described all the specimens of this variety in detail. He noted that the
three from an unknown locality agree so completely that they may be described to-
gether.

The centrodorsal is rather flat, subhemispherical. The very small free dorsal pole
is not sharply differentiated. Prominent interradial processes are present, reaching to
the height of the IBri, but no interradial ridges. The cirri are arranged two or three
in a vertical column.

The cirri are XX-XXV, 14-16; the first three segments are short, and the ante-
penultimate has a conspicuous opposing spine.

The radials are concealed. The IB^ are short and are thickly covered with coarse
tubercles. The IBr2 (axillaries), like the IIBr axillaries, are rhombic. All the IIBr
series are 2, and a single IIIBr series is 2.

Arms arising from a IBr axillary are rare. The arms hi the three specimens num-
ber 17, 19, and 21. So far as may be determined by external observation, the first two
brachials are always united by muscular articulation. The first syzygy is almost with-
out exception between brachials 3+4, the second from between brachials 9+10 to
between brachials 21+22, often between brachials 14+15, 15 + 16, or 17 + 18. The
third syzygy follows at intervals of from 5 to 18, often 7, 8, 9, and 11 muscular articu-
lations, and the distal intersyzygial interval is 3-12 muscular articulations — in one
specimen 4-12, usually 7 or 8; in another 5-9, usually 6-8; and in the third 3-11,
usually 6 or 7.

PI is about 9 mm. long with 25-30 segments of which usually the first four are
strikingly broad and narrowly carinate on both sides; the fifth and sixth segments are
moderately broad and are usually somewhat keeled on one side. The shape of these
proximal segments, or indeed that of the whole pinnule, does not entirely agree with
that of var. insculpta; there are, to be sure, marked variation hi comparable pinnules
of one and the same specimen. The segments following are rectangular or rounded;
elongate segments are lacking. Because of the strong expansion of the four proximal

A MONOGRAPH OF THE EXISTING CRINOIDS 305

segments, the width of the pinnule decreases more or less abruptly, a feature not ob-
served hi var. insculpta; but Hartlaub remarked it should be noted that in some pin-
nules such an abrupt decrease in width is not marked. In contrast to the conditions
hi var. insculpta, the following pinnules as far as P4 are of the same length as PI, though
with fewer (18-20) segments. Regarding the form of these pinnules, it may only be
said in general that they are composed of five broad and short segments, followed by
elongated ones. The first three or four segments are conspicuously carinate, though
in this feature there is great variation. The carination is sometimes more double,
sometimes more single; sometimes the crest of the carination is beset with teeth. When
gonads are developed — appearing first on P4 — the segments over the gonads, usually
the third and fourth, are broadened. From P5, which is 7 or 8 mm. long, the length
of the pinnules decreases. The pinnules of the tenth-fourteenth brachials are about
7 mm. long, that of the sixteenth brachial about 6 mm. The usual length of the pin-
nules of the middle of the arm, 5-6 mm., may be reached with the pinnule of the eighth
brachial. Typical for the middle of the arm are pinnules with two short basal segments
followed by usually 10, rarely 11, elongate ones. Most numerous by far are pinnules
6 mm. long with 12 segments, in marked contrast to var. insculpta in which the usual
pinnules are 3 mm. long with 9 segments. If gonads are developed here — strongly
swollen gonads are lacking — the third and fourth segments are broadened. Toward
the arm tips, on the seventieth to eightieth brachials, the pinnules become more slender;
there is no decrease in the number of their segments, or increase in their length.

The ambulacral plating consists of side and covering plates. The sacculi are
rather small and inconspicuous. The disk is deeply incised.

In the specimen from Blake station 219 the centrodorsal is hemispherical and rather
high. Interradial ridges are here and there evident, as in those just described.

The cirri are XXXII, about 20, longer than those in the specimens described
above. The first three or four segments are short, and an opposing spine is present.

There are 10 IIBr 2 series, and therefore 20 arms.

The first syzygy is always between brachials 3+4, the second from between brachi-
als 10 + 11 to between brachials 17+18, the next after an interval of from 5 to 12,
usually 8, muscular articulations, and the distal intersyzygial interval is from 7 to 10,
usually 7 or 8, muscular articulations. On one arm the second syzygy is between
brachials 8+9 and the third between brachials 34+35. In general the distribution of
the syzygies strongly recalls that of the three preceding specimens.

PI is 8-9 mm. long with 20-25 segments of which the first seven are broad and
those from the second onward are doubly keeled. In some cases this pinnule is only
5 or 6 mm. long, apparently as a result of imperfect regeneration. The shape of the
proximal segments varies from that in the corresponding pinnule in the preceding speci-
mens only in that the keels on the proximal segments are broader. The pinnules
following up to P3 on the arms studied are shorter, 6-7 mm. long, that of the sixth
brachial even 5 mm. long. In two cases the pinnule of the eighth brachial was found
to be exceptionally long, 8 and 9 mm., and in one case barely 4 mm. long showing, how-
ever, clear indications of incomplete regeneration. In view of these varying conditions
in the pinnule of the eighth brachial, Hartlaub was inclined to assume that, as in the
case of the three specimens described, the pinnules as far as the eighth brachial are
normally of the same length as P, and that the abnormal conditions were the result of

306 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

imperfect regeneration after loss, or perhaps of arrested growth. Unfortunately a
study of all the postradial series was not possible on account of the close apposition of
the arm bases. The pinnules of the middle of the arm from about the eighteenth
brachial onward are usually 7 mm., rarely 8 mm., long with about 15 segments of which
the two first are short and those following elongate. Usually when gonads are devel-
oped the 2-4 segments following the second are broadened. In length and in the
number of their component segments the pinnules of the middle of the arm exceed
those of the three specimens previously described. Whether or not the distal pinnules
increase in length cannot be determined because of the poor state of preservation.

The ambulacral plating consists of side and covering plates. The sacculi are
somewhat larger than those of the specimens already described. The disk has been
lost.

In the specimen from Blake station 198 the centrodorsal is rather high and hemi-
spherical, as in the specimen from Blake station 219. The cirri are composed of 15—19
segments, as in the specimens first described.

In general the division series are as in the three first specimens, and in the one
from Blake station 219; but on the 10 IIBr series eight are 2 and two are 4(3+4).
There are 20 arms.

The first syzygy is always between branchials 3+4, the second from between
brachials 17 + 18 to between bracbials 23+24, usually at about the twenty-first brachial.
Only five arms are well enough preserved to permit the determination of the position
of the following syzygies. In these the interval between the second and third syzygies
is 9, 11, 15, 12, and 7 muscular articulations, and the distal intersyzygial interval is
from 5 to 12, usually 10 or 11, muscular articulations. The intervals between the
syzygies are therefore somewhat greater than in the three first specimens, and in that
from Blake station 219.

PI is about 8-9 mm. long with 20-25 segments, of which the first 5 are as a rule
broad and the second-fifth are singly carinate. The pinnules following as far as P«,
about 8 mm. long, are of approximately the same size as PI, as in the other specimens
of this variety. The pinnules in the middle of the arm from about the eighteenth
brachial onward are 6-7 mm. long with 12-15 segments of which the two first are short
and those following are elongate. Usually gonads are developed; in this case usually
only the third and fourth segments are broadened. Whether or not the distal pinnules
increase in length cannot be determined because of the poor state of preservation of
the specimen.

The ambulacral plating consists of side and covering plates. The sacculi are rather
large. The disk is 8 mm. hi diameter, as deeply incised as in the case of the first three
specimens, and as in var. insculpta.

The most important characters of var. tuberosa apart from the ornamentation
according to Hartlaub are as follows. The centrodorsal is subhemispherical or hemi-
spherical with the dorsal pole small and not sharply differentiated and prominent
interradial processes reaching to the height of the IBri, but no interradial ridges. The
cirri are rather stout with 20-32 segments and an opposing spine. The radials are
concealed. The IIBr series are predominantly 2, rarely 4(3 + 4). The arms are 17-20
hi number. The first syzygy is almost always between brachials 3+4, the second from
between brachials 9+10 to between brachials 23+24. PI is about 9 mm. long with

^^^^^^^^1 A MONOGRAPH OF THE EXISTING CRINOIDS 307

20-30 segments of which the basal 4-7 are broad and more or less doubly keeled. The
immediately following pinnules are of the same length as PI, and the pinnules hi the
middle of the arm, from about the twentieth brachial onward, are 6-8 mm. long with
12-15 segments.

Localities. — Blake stations 198 and 219.

Geographical range. — Martinique and St. Lucia.

Bathymetrical range. — From 250 to 276 meters.

Thermal range.— From 11.39° to 13.89° C.

CRINOMETRA BREVIPINNA var. MARGARITACEA A. H. Clark

PLATE 31, FIGURE 94
[See also vol. 1, pt. 2, figs. 683, p. 338, 746, p. 349.)

Crinometra margaritacea A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p 645 (description;
Albatross station 2154); U. S. Nat. Mus. Bull. 82, vol. 1, pt. 2, 1921, fig. 683, p. 338.

Description. — The centrodorsal is thick discoidal or flattened hemispherical with
the bare polar area 3 mm. in diameter, covered with small high tubercles. The cirrus
sockets are arranged in 10 closely crowded and somewhat irregular columns, two to a
column, the columns sometimes with a row of small tubercles between them.

The cirri are XX, 13-15, 20 mm, long. The first segment is very short, the second
and third are twice as broad as long, the fourth is as long as, or somewhat longer than,
broad, and those following are about one-third again as long as broad, or rather less,
becoming about as long as broad toward the end of the cirrus. The antepenultimate
segment is slightly longer than those preceding. The penultimate segment is twice as
long as broad, slightly less in diameter than those preceding. The cirrus segments
have slightly prominent distal ends, and the last six or seven have a slight low and
broad tubercle hi the median line of the distal edge on the dorsal side which becomes
more prominent distally. The opposing spine is very small, terminal in position, directed
obliquely forward. The terminal claw is about three-quarters the length of the penulti-
mate segment, moderately slender and moderately curved.

The ends of the basal rays are visible hi the angles of the calyx. They bear one
or more long tubercles.

The radials are concealed. The IBrj are very short, five or six tunes as broad as
long, with the edges parallel and slightly curved. The IBr2 (axillaries) are rhombic,
about two and one half times as broad as long. The IIBr series are 2. The IIIBr
series are 2, developed interiorly, but never present in the full series. The division
series and first two brachials are slightly convex dorsally and are laterally hi close
apposition and sharply flattened. The axillaries are separated on their lateral contig-
uous edges, forming rhombic water pores. The first and second brachials are similarly
separated ulteriorly. The ornamentation consists of moderately large blunt tubercles
distributed evenly over the surface of the division series, becoming less marked after
the second brachial and gradually disappearing at about the end of the proximal fourth
of the arms. The IIBr and IIIBr series and the first two brachials have a low but
prominent rounded narrow median carination. This is continued on to the arm
bases hi the shape of prominent median tubercles on each brachial, these tubercles
disappearing at about the end of the proximal fourth of the arms. The arms are
practically smooth in the distal two-thirds.

308 BULLETIN 82, UNITKD STATES NATIONAL MUSEUM

The arms are 21-29 in number and resemble in structure those of related forms.
The first 18 or 20 brachials are laterally flattened.

The pinnules resemble those of related forms but are somewhat more slender,
the genital pinnules not being so much expanded.

The disk is completely covered with a pavement of very small plates. Side and
covering plates are well developed along the ambulacral grooves.

The color hi alcohol is white or dull yellowish.

Localities. —Albatross stations 2154, 2155, 2156, 2319-2350.

Geographical range. — Reported only from off northern Cuba.

Bathymetrical range. — From 508 to 567 meters.

CRINOMETRA BREVIPINNA var. DIADEMA (Hartlaub)

Antedon brevipinna var. diadema HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323
(in key), p. 337 (description; Blake station 101).

Description. — A brilliant white specimen, the lightest colored of all the specimens
he studied, from Blake station 101 was regarded by Hartlaub as representing a special
variety.

The centrodorsal is flat with a flattened dorsal pole which is rather large and is
beset with coarse and relatively high toothlike or spiny processes. The corresponding
processes in var. insculpta are fine and not so high. There are also small tubercles and
teeth between the cirri and on the interradial processes. Interradial ridges are present,
but are not sharply elevated. The cirri are arranged in vertical pairs.

The cirri are XIX, about 12; the distal segments have no processes on their thick-
ened distal edges, but an opposing spine is present.

The radials, partially concealed, are in part deeply withdrawn within the calyx
and are almost wholly covered by the IBri, which are flat and bowed. The IBr2
(axillaries) are rhombic to hexagonal, without a prominent proximal process. The
IIBr series are 2. The first four brachials are rectangular; these are followed by a few
bluntly wedge-shaped ones, then two or three approximately rectangular, changing
rather suddenly to nearly triangular, these persisting to the arm tips. The change in
form of the brachials is not so abrupt as hi other varieties.

Ornamentation is relatively slightly developed. That of the centrodorsal has been
described. On the borders of the IBrj there are a few coarse tubercles which make these
ossicles appear dentate or crenulate. The proximal border of the IBri, like that of the
IBr3 (axillary) is produced in overlapping scalelike fashion. The axillary has merely
marginal decorations of the same sort and a median ridge, but is otherwise smooth.
On arms arising from a IBr axillary the two first brachials are variable. They are
partly beset with several coarse tubercles, but in most cases then" surface is flat or only
slightly uneven. The proximal border of the first brachial is as a rule dentate. In the
middle there is a ridge, or a small round and flattened median tubercle which becomes
more pronounced on the third brachial, on the later brachials, in the middle of the raised
distal edge, appearing markedly higher and knoblike, in this form and position giving
an extremely characteristic fascies to the ornamentation of this variety. Equally
characteristic is the fact that from the fifth brachial onward the distal edge is elevated
and begins to turn back over the dorsal surface of the brachials in a conspicuous manner.
Besides the large knoblike median tubercle there are several smaller ones on the distal

A MONOGRAPH OF THE EXISTING CRINOIDS 309

border. From about the ninth to the thirteenth braehials the distal edges are turned
downward, without becoming typically liplike. At about the eighteenth to twentieth
brachial the knoblike median tubercle becomes inconspicuous, and at the same time
the distal edge becomes lower and somewhat crenulate, later smooth and slightly
thickened.

In arms arising from a IBr axillary the first syzygy is between braehials 3+4, in
arms arising from a IIBr axillary, so far as may be judged from the few arms preserved,
between brachials 1 + 2. The second syzygy in arms arising from a IBr axillary is
between brachials 16 + 17 or 17+18, and the third from between brachials 22 + 23 to
between brachials 25+26; the distal intersyzygial interval is 6, 7, or 8 muscular articula-
tions.

P, is about 8 mm. long with about 20 segments of which the second-fifth are
broadened and carinate. None of the following pinnules are preserved entire. The
pinnules of the seventh and ninth brachials are 6-7 mm. long with 14 or 15 segments of
which the first 3 or 4 are short, those following elongate. The succeeding pinnules, ha
the middle of the arm, are shorter, about 5 mm. long, with 10-12 segments of which
the first two are short and the remainder elongate; where gonads are developed the third
and fourth segments are broadened.

The ambulacral plating consists of prominent side- and covering-plates. The
sacculi are colorless. The disk has been lost.

The whole animal, in alcohol, is shining white except for the brownish dorsal pole
of the centrodorsal.

Locality. — Blake station 101.

Geographical range. — Known only from northern Cuba.

Bathymetrical range. — One record, 320-457 meters.

CRINOMETRA BREV1PINNA var. POURTALfcSI (P. H. Carpenter)

Antedon pourtalesi P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, pp. 54, 208,

209, 211, 212 (in key), 368, 379 (range).
Antedon brevipinna var. pourlalesi HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 339 (description; Blake station 219), pi. 14, fig. 1.

Description. — Hartlaub wrote that two specimens from Blake station 219 which
show little agreement either in the ornamentation of the brachials or in other respects —
as for instance the form of the IBr series — were distinguished by Carpenter in the
Challenger report as representatives of a new species which he called Antedon pourtalesi.

The characters of this new species as given by Carpenter in his key to the species
of the Spinifera group were: Cirri without definite arrangement on the centrodorsal,
composed of 15-25 stout and usually smooth segments; IIBr series and lower brachials
with distinctly flattened sides ; calyx and arm bases irregularly tubercular ; the pinnules
from the tenth to the twentieth brachials have the third-fifth segments flattened and
expanded laterally. In Carpenter's key brevipinna was said to differ from pourtalesi
only in having the genital pinnules comparatively slender with very slightly expanded
segments.

Hartlaub said that in studying the two type specimens of the so-called species
pourtalesi he found hi the larger, the only one he regarded as representing his var.
pourtalesi, that the genital pinnules began with P2. At first the gonads are situated
rather high on the pinnules, at about the height of the seventh and eighth segments,

310 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

and then, approximately in the range given by Carpenter, that is from the tenth to
the twentieth brachials, they move nearer the base, to the height of the third to fifth
or third and fourth segments. The third to fifth, or third and fourth, or fourth and
fifth segments are then flat and laterally broadened. This broadening, which Hartlaub
frequently pointed out in connection with other varieties, is purely an accompaniment
of the swelling of the gonads and is similarly developed in other specimens of brevipinna.
It is usually lacking in smaller (younger) individuals since in them the gonads contain
no ripe sexual cells. Hartlaub expresses his surprise that Carpenter, to whom this
relationship between the ripeness of the gonads and the expansion of the pinnule
segments covering them must have been known, should have employed such an un-
stable character for the separation of the two species. He said that he must strongly
oppose the supposition that the pinnule segments overlying the gonads in Carpenter's
specimens of povrtalesi are significantly and constantly stouter than those in typical
specimens of brevipinna — for example, in his var. elegans. The assumption that rel-
atively slender genital pinnules with only slightly broadened segments are character-
istic of brevipinna is untenable. So Hartlaub saw no reason for accepting Carpenter's
new species.

As already mentioned, the two specimens determined by Carpenter as pourtalesi
show rather wide differences. The smaller specimen shows spiny ornamentation,
and therefore will be described under the varieties of the Spinosa type. The larger
specimen, because of its developed ornamentation is naturally associated with the
varieties of the Tuberosa type. Its characters are as follows.

The centrodorsal is subhemispherical with a scarcely noticeable dorsal flattening.
The bare uneven dorsal pole is small with an inconspicuous central cavity. It bears
a few rather sharp tubercles, which are also found between the cirri and on the slightly
developed interradial processes.

The cirri are XXXVI ; none of them are preserved entire. According to Carpenter,
who saw the specimen when it was in a better state of preservation, there were 15-20
cirrus segments. The distal segments, according to Carpenter, are smooth, a state-
ment which he applies also to brevipinna, but according to Hartlaub's observations
does not apply throughout; rather in brevipinna the distal edges of the segments in the
outer half of the cirri are more or less produced, and the penultimate bears an opposing
spine.

The radials are wholly concealed. The IBri are flat and bowed into a kind of
scallop with the convexity proximal. The IBr2 (axillaries) are relatively flat and
approximately rhombic. The form of the elements of the IBr series recalls forcibly
that in the var. tuberosa. All 10 IIBr series are 2, and the 12 IIIBr series also are all 2.

There are 32 laterally compressed arms of which 8 arise from IIBr axillaries and
the others from IIIBr axillaries. In the region of the proximal brachials there is to
be noticed a double change in form which is best observed on the basis of the direction
of the articulations. The articulations of the first three or four brachials are transverse,
of the following three or four more or less diagonal, of the next two or three transverse,
then strongly diagonal to the arm tips. This feature is much more strongly brought
out in the specimen referred to the Spinosa type (var. coronata).

The ornamentation of the division series, as already noted, agrees naturally with
that of var. tuberosa, appearing here in reduced form. Also here the basic element of

A MONOGRAPH OF THE EXISTING CRINOIDS 311

the ornamentation is mostly of usually blunt tubercles, which are exceedingly few.
Only the IBri is beset with numerous tubercles, among which a larger rounded median
tubercle especially stands out. Except for this, there is only a slight tuberculation on
the lateral borders of the ossicles, or in their vicinity, as far as the IIIBr series where
it becomes quite inconspicuous. Besides this, the proximal border of the axillaries
is tubercular or slightly corrugated. The rest of the dorsal surface of the division
series is smooth and only shows a median swelling which does not form a median ridge.
On the lowest brachials ornamentation is only indicated. The produced distal ends
of the following brachials are thickened and with few exceptions smooth; there is no
formation of typical recurved lips such as are present in var. tuberosa. Here, and
toward the arm tips, a median sharpening of the brachials, a sort of carination, may
sometimes be distinguished.

The first syzygy lies at the same height on all the arms. On the arms arising from
a IIBr axillary the first syzygy is between brachials 3+4, on arms arising from a
IIIBr axillary between brachials 11 + 2. The second syzygy in arms arising from a
IIBr axillary is from between brachials 16 + 17 to between brachials 27+28, and on
arms arising from a IIIBr axillary from between brachials 15 + 16 to between brachials
35+36; but in the latter case there may be syzygies between brachials 4 + 5, 5+6,
and 9+10. In arms arising from both IIBr and IIIBr axillaries the distal intersyzygial
interval is from 9 to 20, usually 12-16, muscular articulations.

PI is about 10 mm. long with 25-30 short and approximately quadrangular segments
of which the first five are broad and feebly carinate. The pinnules following are shorter.
The pinnules in the middle of the arm are 5-6 mm. long with 12-13 segments of which
the first two are both short, those following elongate. Gonads are usually present,
roofed over by the modification of the segments already described. Individual gonads
occur nearly to the arm tips. Here the pinnules are very slender, apparently some-
what longer, and are composed of about 15 segments.

The arms are estimated as about 120 mm. in length.

The ambulacral plating is composed of rather large side and covering plates.
The sacculi are rather small. The disk is typically rather deeply incised, 15 mm. in
diameter. In alcohol the disk is light gray, the skeleton gray with a yellowish tinge,
the centrodorsal and base of the postradial series somewhat darker.

Locality. — Blake station 219.

Geographical range.- — Off St. Lucia; according to Carpenter "Caribbean Islands."

Bathymetrical range. — The only definite record is 276 meters; Carpenter gives the
range as 227-479 meters.

Thermal range. — One record, 13.89° C.

CRINOMETRA BREVIPINNA var. LAEVIS (Hartlaub)

Anledon brevipinna var. laetris HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323 (in
key), p. 342 (description; Blake station 269), pi. 11, fig. 6.

Description.— A medium-sized specimen, unfortunately mutilated, from Blake
station 269 was considered by Hartlaub as a representative of a special variety showing
some characteristic features.

The centrodorsal is subhemispherical, low, with a rounded bare dorsal pole studded
with coarse tubercles, which are also found between the cirri and especially on the well
developed interradial processes.

312 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XV, with three short and strikingly thick basal segments. No cirri
are completely preserved.

The radials are concealed. The IB^ and the hexagonal IBr2 (axillaries) are rather
flat; the axillaries lack a posterior process. The IIBr series are 2.

The ornamentation as far as the third brachial is very characteristic. The IBri
bear rather large tubercles which are mostly marginal, and in addition a conspicuous
median tubercle. The IBr2 (axillaries) have a thickened and somewhat produced
dentate proximal border, but the distal border is lower and usually smooth; on the
otherwise smooth surface there is a strongly produced median ridge. On the IIBr
series and first three brachials this median ridge or median swelling is the most con-
spicuous and, apart from slight irregularities of the surface, the only ornamentation.
The angular sharpening of the ossicles produced iu this way, which is evident in part
also on the brachials, furnishes an easy recognition mark for this variety, as does the
lack of all ornamentation from the third brachial outward, where there is nowhere any
trace of the thickening of the distal edges that is in other varieties almost always
present.

There are 15 arms. The articulations of the first three brachials are transverse,
those following diagonal, the brachials changing their form accordingly. The arms
appear stiff. Unfortunately the arms are poorly preserved so that it cannot be deter-
mined whether they decrease in width rather rapidly or gradually from the broad base.
The middle portion of the arms is already strongly compressed laterally. This decrease
in width of the arms is exceedingly characteristic of this variety.

In arms arising from a IBr axillary the first syzygy is as a rule between brachials
3+4, in arms arising from a IIBr axillary between brachials 1 + 2. In the single better
preserved arm arising from a IBr axillary the following syzygies are between brachials
19 + 20, 26 + 27, and 30 + 31.

None of the lower pinnules are preserved entire. They appear to be short with
strong carinate basal segments. A pinnule from the middle of the arm is 3 mm. long
with 8 segments which, with the exception of the first two, are elongate.

The arms have an estimated length of 40-50 mm.

The ambulacral plating consists of stout side and covering plates. Sacculi are not
apparent. The disk is high, deeply incised, 5 mm. in diameter.

In alcohol the skeleton is whitish gray, the disk darker gray.

Locality. — Blake station 269.

Geographical range. — Known only from off St. Vincent.

Bathymetrical range. — Known only from 227 meters.

Thermal range. — One record, 14.17° C.

CRINOMETRA BREV1P1NNA TOT. BREVIPINNA (PourtalSe)

Comatula brevipinna POURTALES, Bull. Mus. Coinp. Zool., vol. 1, No. 6, 1868, p. Ill (description;
off Havana, 270 fathoms; Corwin [station 2]).

Antedon brevipinna P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, part 60, 1888, pp. 54,
207, 208, 211, 212 (in key), 378 (Straits of Florida; 270 fathoms [Corwin station 2]).— HAHTLAUB,
Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 313 (reprint of original description and rede-
scription of the type specimen from Corwin station 2; descriptions of specimens from Blake stations
232, 269), pi. 1, figs. 17, 18, 21, pi. 3, figs. 1, 3, pi. 4, fig. 2.

Crinometra brevipinna A. H. CI.ARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 658
(off St. Thomas; 240 fathoms).

A MONOGRAPH OF THE EXISTING CRINOIDS 313

Description. — Hartlaub's redescription of the type specimen from Corwin station 2
is as follows: The centrodorsal is dome-shaped with a bare dorsal pole; there are
strong interradial processes, but no interradial ridges.

The cirri are XVI, all broken off beyond a few basal segments. According to
Pourtales they have about 15 long segments. Hartlaub said that the first two segments
are very short, those following markedly longer than broad.

The radials are entirely visible; in the proximal portion of the median line they
bear a conspicuous tubercle. They are laterally in close contact, and then- lateral
edges show several small tubercles or dentations which in many places interdigitate
with those on the neighboring radials. Their distal border is gently concave. The
IBri and IBr2 (axillaries) have a sharp median keel; together they form a synarthrial
tubercle which does not appear as a unit, since the two ridges are separated by the
articulation. The IB^ are broadly in contact laterally; their lateral borders, like
those of the radials, are tubercular or dentate, and then- proximal border is slightly
convex and bears very small tubercles. The IBr2 (axillaries) are pentagonal; their
proximal and distal edges are bowed outward and are in places slightly tubercular.
They are free laterally. The lateral borders are dentate, but lateral contact surfaces
are present. There are two IIBr 2 series. In one of these, which is fully developed,
the lateral borders of the ossicles are free, but the inner sides of the first two brachials
are in close contact; both these brachials have a slight median elevation of the dorsal
surface. The other IIBr series is regenerating. It is followed by a IIIBr 2 series.

There are 13 arms with an estimated length of 35 mm. The first two brachials are
short, broader than long, approximately rectangular; their lateral borders are dentate.
From the fourth brachial onward the brachials become longer and more squarish;
their proximal and distal ends show a sharp process which is visible on the dorsal
surface of the arms. In the middle of the arms the brachials become approximately
wedge-shaped and longer, and the processes arise on the sides of the arms. All the
brachials are smooth. The ends of the arms are broken off.

In arms arising from a IBr axillary and in those arising from a IIBr axillary the
first syzygy is between brachials 3+4; in arms arising from a IIIBr axillary it is between
brachials 1 + 2. The second syzygy is from between brachials 15 + 16 to between
brachials 17 + 18, and the third is between brachials 21+22 or 22+23.

PI is about 3 mm. long, longer than any of those following, with about 13 segments
of which the basal three or four are broader than long and the second-fourth are mod-
erately carinate; from the fifth onward the segments become gradually narrower and
longer. P2 and P3 are shorter, about 2 mm. long; the two or three lowest segments
are broad. In the pinnules following these become more slender and toward the middle
of the arm the basal segments no longer differ from those following. These pinnules,
about 2 mm. long, have 6 or 7 stout segments of which the first two are short and the
terminal are markedly longer than those of the earlier pinnules. Pourtalds said that
the pinnules in the middle of the arms have 5 segments.

The ambulacral surface of the arms and pinnules show sacculi and prominent
plating. The disk is 3 mm. in diameter.

A small specimen from Blake station 232 is not half so large as Pourtales' type
specimen, the arms being only about 15 mm. long. Some of the cirri are complete.
They have 12-14 segments of which the first two are short and the third, fourth, and

843803—50 21

314 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

fifth are markedly elongate, the third the longest; the segments following become
gradually shorter, and their distal ends become broader and show produced points
so that the dorsal profile of the cirri here appears serrate. The opposing spine is
directed outward.

The radials are largely visible. The IBr2 (axillaries) show traces of dentation on
the proximal and lateral borders, all the other ossicles of the division series being
smooth. The arms are all broken off near the base; their number is presumably 10.
Hartlaub remarked it is noteworthy that while the radials are in close lateral contact
the ossicles of the IBr series are laterally entirely free and do not have sharply flattened
sides.

A second specimen from Blake station 232 is somewhat larger than the type speci-
men, with the arms about 40 mm. long. Most noticeable in this specimen is the shape
and tilelike imbrication of the elements of the IBr series. As in the type specimen,
the radials bear a moderately pointed median tubercle. These tubercles stand in
approximately the same height as the strong interradial processes of the centrodorsal
so that the base of the postradial series shows a crown of 10 tubercles. The IBi'i,
tapering in its distal half, is approximately trapezoidal and, together with the axillary,
bears a conspicuous median angular tubercle and a produced and overlapping proximal
border. The IBr2 (axillary) is almost triangular. One IIBr 2 series is present.

There were apparently 11 arms. On arms arising from a IBr axillary the first
syzygy is between brachials 3+4 and the second from between brachials 14 + 15 to
between brachials 17+18. Like the elements of the IBr series, the elements of the
IIBr series bear an elongate median crest.

Hartlaub noted that here for the first time there is an indication of the brachial
ornamentation so highly developed in the large specimen. The articulations of the
brachials are broad and everted so that the individual brachials stand out strongly
and the dorsal profile of the arms is almost serrate or dentate. P, is composed of 12
or 13 segments of which the two first appear approximately triangular, those following
more rectangular; the second and third are somewhat carinate outwardly; all the
segments are of about the same length. Ptt has four short and approximately squarish
segments, those following being longer. P2 has 10 segments of which the first three
are short and the remainder elongated. Pa, which is short with 8 or 9 segments of
which the first two are short and the others elongated, represents essentially the typical
form of pinnule in the middle of the arm. The length of the pinnules apparently
decreases gradually from P! to about P9.

A third specimen from Blake station 232 is larger with the arms about 50 mm. long.
The cirri have 10-14 segments of which the first two are short and those following
elongate, and the penultimate bears an opposing spine. The form and the tilelike
imbrication of the elements of the IBr series are much less characteristic than in the
other specimens. In the position of the first and second syzygies and in the presence
of one IIBr 2 series there is, however, great similarity; but the IBr axillary is not
triangular but almost rhombic, and there is a slight tuberculation or dentation on the
overlapping proximal edge of the elements of the IBr series.

P! is about 6 mm. long with 20-22 segments of which the first five are broad and
somewhat carinate and those following are elongate, the terminal becoming shorter
again and very small. The pinnules following become gradually shorter. Pd or Pe is

A MONOGRAPH OF THE EXISTING CRINOIDS 315

2-3 mm. long with 8 or 9 segments, of which the two basal are broad and short and the
others elongate. As in the preceding specimen, it represents the form typical for the
middle of the arm.

The fourth specimen from Blake station 232 is larger than the type specimen, having
the arms with an estimated length of 45 mm. Hartlaub says it is rather different from
the preceding specimens, and it is doubtful whether it belongs to the same species.
Regenerating arms occur on each of the five postradial series. The absence of all
ornamentation on the division series is striking. The radials and the elements of the
IBr series are smooth; at the most a suggestion of a production of the proximal border
of the IBr2 (axillary) may be noted. The radials are visible, somewhat overlapped by
the produced proximal edge of the IBr^ The IBr2 (axillaries) have a proximally directed
posterior process. Subradial clefts occur between the conspicuous interradial processes
of the centrodorsal. The IBri and following ossicles have sharply flattened sides.

The number of arms originally possessed by this specimen cannot now be determined.
There are only two of the original arms arising from a IIBr axillary. In one of these the
first syzygy is between brachials 3+4, the second is between brachials 19+20, and the
third is between brachials 27 + 28; in the other the syzygies are between brachials 5 + 6,
18+19, and 26+27. In addition to this IIBr 2 series, there is another similar one, and
also one IIBr 4(3+4) series. There are two IIBr 1 series, and one IIBr 2(1+2) series.

PI is 6 mm. long with 12 segments, all of the same length except the first which is
shorter. The pinnules in the middle of the two arms originally present are composed of
7 or 8 stout segments; characteristic of these pinnules is the fact that from the third to
the penultimate segment they are of approximately the same width, only the terminal
segment tapering. The two basal segments are short and moderately broad, all the
others elongate.

A medium sized specimen from Blake station 269, according to Hartlaub, is better
preserved and therefore permits a better comparison with the type specimen. It is
larger than those previously noticed, with an arm length of about 55 mm. It is note-
worthy that on the centrodorsal, which is more flattened than that of the type specimen,
the bare dorsal pole is studded with a strongly developed tubercular efflorescence.
Smaller tubercles are found on the sides between the cirrus sockets and also on the not
especially well developed interradial processes. An opposing spine is developed, as in
the first specimen from Blake station 232. In contrast to the type specimen, the
radials are scarcely visible. The IBi'i are rather flat, with a well developed median
tubercle; small blunt tubercles also occur on the dorsal surface and on the distal
edge; the lateral borders are dentate and irregular, as in the type specimen. The
ornamentation of its proximal border is more developed than in the type specimen —
everted and winglike, and also pleated. The IBr2 (axillaries), which are more rhombic
than pentagonal, have a broad median crest; their lateral borders show here and there a
typical dentation; the proximal and distal edges are essentially like those of the IBri.
As a rule the IIBr series are 2, but one IIBr 4 series is present which all indications
suggest owes its origin to regeneration. The elements of the IIBr series have everted
proximal borders and often typically dentate lateral edges, as well as a conspicuous
median elevation; the axillary is approximately rhombic. The IIBr series and first two
brachials have sharply flattened lateral borders.

316 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

There were at least 15 arms. The first syzygy is usually between brachials 3+4
as in the type specimen, and the second is far distant, from between brachials 13 + 14 to
between brachials 24+25.

As in the type specimen, PI is the longest with about 18 segments of which the
basal three or four are broad and keeled, those following always short, becoming
gradually narrower. The three basal segments of the following pinnules up to P3 are
also broad and carinate. The short and stout pinnules from the middle of the arm have
mostly 8 segments of which the two basal are broad and those following elongate.
Toward the end of the arms the pinnules appear to become somewhat longer again.
The individual brachials are emphasized by broad and deep-lying articulations, which
give the arms a characteristic appearance.

Another somewhat larger individual from Blake station 269, which has only a single
arm preserved beyond the base, has an estimated arm length of 65 mm. In essentials
it agrees with the preceding. The ornamentation of the centrodorsal and of the
division series is in close agreement. The radials are not visible. The IIBr series are 2,
and a single IIIBr 2 series is present. The first syzygy is between brachials 3+4, and
the proximal three or four segments of Pj, which hi no case is preserved entire, are in
this specimen also broad and carinate.

Localities. — Cormn station 2; Blake stations 232, 269; off St. Thomas.

Geographical range. — From northern Cuba to St. Vincent.

Bathymetrical range. — From 159 to 494 meters.

Thermal range— From 14.17° to 16.67° C.

Remarks. — The var. brevipinna has no real validity in fact. Pourtales' type spec-
imen and the specimens described by Hartlaub are young individuals in which the
varietal characters have not as yet become distinctive. Pourtales' type specimen is
probably simply a young individual of var. granulifera, and the specimens from Blake
stations 269 and 232 appear to be young individuals of var. insculpta.

CRINOMETRA BREVIPINNA Tar. SPINO9A (Hartlanb)

Antedon brevipinna var. spinosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323 (in
key), p. 343 (description; no locality), pi. 11, fig. 8.

Description.- — Hartlaub said that a rather small specimen from an unknown locality
with the arms about 70 mm. long forms in regard to its ornamentation — uniformly
distributed spines — an exceedingly interesting parallel to the second Martinique speci-
men of what he considered to be granulifera (see page 326). To Hartlaub it seemed
that this specimen represented a transition to granulifera, although it shows various
differences.

In particular the centrodorsal is markedly flatter than the more hemispherical
centrodorsal of the specimen of granulifera. Like most specimens of brevipinna it pos-
sesses a typical flattened bare dorsal pole, which is uneven. No interradial ridges are
present, but there are prominent interradial processes.

The cirri are XXII, 14-16; an opposing spine is present.

The radials are flat, obscured, though entirely visible. In the specimen of granuli-
fera mentioned the radials are clearly visible. In both specimens there are narrow sub-
radial clefts. The IBri are also flat; the IBr2 (axillaries) are pentagonal, not especially

A MONOGRAPH OF THE EXISTING CRINOIDS 317

high, with a straight proximal border. All the IIBr series except for a single deformed
one are 2, in contrast to the condition in granulifera. There are no IIIBr series.

There is striking agreement between the present specimen and the specimen of
granuli/era in respect to the ornamentation of the division series and lower brachials.
The surface of the ossicles is beset with thick, erect, coarse, sometimes sharp and some-
times more blunt spines or teeth which are partially coalesced, their distribution being
approximately uniform without a tendency to greater development along the borders
of the ossicles. The distal limit of this ornamentation lies at about the tenth or twelfth
brachial. The surface of the following brachials is in both cases flat, and their edges are
thickened and slightly crenulate.

There are 16 arms. The change in shape of the lower brachials is noteworthy. Up
to the third brachial on arms arising from a IIBr axillary, or fourth brachial on arms
arising from a IBr axillary, the articulations are transverse and the brachials therefore
discoidal or quadrangular; then follow about four bluntly wedge-shaped brachials with
diagonal articulations; then one or two rectangular brachials with transverse articula-
tions, which usually delimit the basal ornamentation. The brachials following are longer
and approximately triangular. Toward the arm tips the brachials again become shorter
and more bluntly wedge-shaped, and finally almost cornet-shaped with widely flaring
ends. Hartlaub remarked it is worthy of note that a similar condition may be seen on
some of the arms of the granulifera specimen, especially in the lower brachials.

The sequence of the syzygies on two similarly preserved arms arising from a IBr
axillary are: Between brachials 3+4, 5+6, and 14+15; and on the other arm between
brachials 3+4 and 16+17. On arms arising from a IIBr axillary the first syzygy is
almost always between brachials 1+2, as in the granulifera specimen. In a few cases
this is followed by a syzygy between brachials 3+4; whether this last is present or not
the next syzygy is from between brachials 14 + 15 to between brachials 20+21, and that
following is from between brachials 22+23 to between brachials 28+29. A syzygy
between brachials 10 + 11, often present in granulifera, Hartlaub could not find in this
specimen.

On arms arising from a IBr axillary PI is unfortunately preserved only as far as the
fourteenth segment; the first five segments, as in PD in the specimen of granulifera, are
broad with a spiny border. On arms arising from a IIBr axillary PI is shorter with fewer
segments, about 5 mm. long with about 15 segments of which the first four are also broad-
ened and spiny edged. The following pinnules gradually decrease in length and in the
number of their component segments. From about P4 onward the pinnules are short,
only 4 mm. long, with about 7 segments of which the first two are short and those fol-
lowing are elongated. In a few pinnules in which gonads are in process of formation,
the third and fourth segments are broadened. Toward the arm tips the pinnules become
longer again; here they are slender, about 5 mm. long, with 10 segments.

The ambulacra! plating consists of prominent side and covering plates. The sacculi
are rather small. The disk is 6 mm. in diameter, brown, and rather deeply incised.

The skeleton, in alcohol, is dingy yellow browtf.

Locality. — West Indies.

318 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

CRINOMETRA BREVIPINNA Tar. GEMMATA A. H. Clark

PLATE 30, FIGURE 92
[See also vol. 1, pt. 2, fig. 679, p. 338.]

Crinometra gemmata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 647 (description; Albatross
station 2330); U. S. Nat. Mus. Bull. 82, vol. 1, pt. 2, 1921, fig. 679, p. 338.

Antedon granitlifera (part) HABTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 298 (second
specimen from Martinique), pi. 5, figs. 7, 9, pi. 12, fig. 8.

Crinometra ornata H. L. CLARK, Bull. Lab. Nat. Hist. Univ. Iowa, vol. 7, No. 5, 1918, p. 11 (Bahama
Expedition stations 9, 16; notes).

Description. — The centrodorsal is hemispherical with the bare polar area small and
papillose. The cirri are arranged in two irregular crowded rows, showing a tendency
toward a columnar arrangement, two columns to each radial area.

The cirri are XX, 12-15, from 20 to 25mm. long. The first segment is very short,
the second is twice as broad as long, the third is nearly as long as broad, the fourth is
half again as long as broad, the fifth-seventh are about twice as long as broad, and
those following slowly decrease in length to about half again as long as broad on the
antepenultimate. The penultimate segment is twice as long as broad, slightly less in
lateral width than those preceding. The distal edge of all the segments is slightly
produced, overlapping the bases of the segments succeeding, and the terminal six to
eight have slight terminal spines on the dorsal side, most developed on the antepenul-
timate. The opposing spine is small, terminal, and directed obliquely forward.

The ends of the basal rays are visible as elongate tubercles in the angles of the calyx;
they are usually covered with short fine spines.

The radials are concealed, or just visible over the ends of the basal rays. The
IBri are very short and bandlike, of uniform height, strongly curved, with the proximal
edge everted and dentate; they bear a row of small pointed tubercles which are some-
times more or less confluent midway between the anterior and posterior borders. The
IBr2 (axillaries) are rhombic, two-and-one-half times as broad as long, with the anterior
and posterior angles approximately equal and the lateral edges about equal to those of
the IBri. The IIBr series are 4(3+4), in one specimen twice 2. The IIIBr series are
2(1+2), but only a single one is present, developed interiorly. The division series are
in close lateral apposition and are sharply flattened laterally. They are strongly and
evenly convex dorsally, so that the dorsal portion of PD is exposed. The division series
and arms as far as the fourteenth brachial are thickly beset with numerous small sharp
conical tubercles which exhibit a tendency to arrange themselves in horizontal rows;
these become more numerous and more slender along the edges of the ossicles of the
division series. Seen without a glass, the proximal portion of the animal has the
appearance of being finely and evenly granulated.

The 19-21 arms are from 110 to 125 mm. long, except for the basal ornamentation
resembling those of other forms of the species.

The pinnules in general resemble those of the other forms. On the ornamented
proximal portion of the arms they are strongly carinate, the carination being more or
less coarsely tubercular or irregular. The third and fourth segments of the genital
pinnules are considerably expanded. The distal pinnules are 8 mm. long.

The disk is completely covered with a pavement of very small plates. Side and
covering plates are well developed along the pinnule ambulacra.

A MONOGRAPH OF THE EXISTING CRINOIDS 319

The color in alcohol is white.

Notes. — Dr. Hartlaub sent me for criticism the proof of his plate 5 and, as he
mentions on page 300, I identified his second specimen of Antedon granulifera from
Martinique (fig. 9) as this form.

This specimen is considerably smaller than the first (see under var. granulifera,
p. 330). While in the latter the IBri is 4 mm. broad, in this it measures scarcely 3 mm.
But in spite of this the arms are of considerable length, one of them, measured with
a thread, reaching 140 mm.; it is broken at the tip and must have been 20 mm. longer.
The expanse of this specimen was estimated at about 310 mm.

There are 16 arms. All the IIBr series are 4(3+4). There are no IIIBr series
and one of the postradial series lack IIBr series. Hartlaub says that the ornamentation
is not dissimilar to that of the small specimen of var. granulifera from Blake station
34, though here the lower brachials are thickly beset with erect coarse spines which
are quite irregularly placed and partially, through fusion of several into one, become
more dentate. The largest spines are on the dorsal surface of the segments, the edges
of the brachials carrying smaller ones. On the division series the spines are markedly
smaller. On the IBr series a weak median ridge may be distinguished.

In the four arms arising from a IBr axillary the sequence of the syzygies is as
follows: (1) between brachials 3+4, 14 + 15, 19 + 20, 25+26, 32+33, and 37 + 38;
(2) bet ween brachials 3 +4, 10+11, 15+16, 22+23, and 28+29; (3) between brachials
3+4, 5 + 6 (?), 12 + 13, 22+23, 29+30, and 37+38; (4) between brachials 3+4,
16+17, 19+20, 24+25, 32+33, and 38+39.

In five arms arising from IIBr axillaries the syzygies are as follows: (1) between
brachials 1+2, 3+4, 10+11, 18+19, 26 + 27, and 32+33; (2) between brachials
1+2, 13 + 14, and 20 + 21; (3) between brachials 1+2, 12 + 13, and 19+20; (4)
between brachials 1+2, 10 + 11, 19+20, 27+28, and 32+33; (5) between brachials
1+2, 6 + 7, and 16+ 17. In a study of other arms Hartlaub found commonly a syzygy
between brachials 10+11, which was sometimes the second, sometimes the third syzygy.

PD is about 10 mm. long and is composed of about 30 short and broad segments.
Their dorsal edge, of which a broad strip is visible between the appressed arms, is
sculptured in the same way as the arm bases. P! on arms arising from a IBr axillary
is similar. The proximal pinnules are markedly shorter than those of the third
specimen (var. granulifera) from Martinique (see page 330).

Dr. Hubert Lyman Clark referred one good specimen from the University of
Iowa's Bahama Expedition station 16 and arm fragments from station 9 to Crinometra
ornata. He said that the specimen and fragments of this Crinometra do not correspond
in detail with Hartlaub's description and figures, but it is better to refer them to the
same name than to introduce a new name into this already badly confused group.

He said that the individual before him has the centrodorsal so thickly covered
with cirri that it is difficult to determine its size and shape. At the dorsal pole are a
few high, compressed, irregular granules and ridges.

The cirri are about XX, 17-20. The penultimate bears a conspicuous opposing
spine while the 3-6 preceding have a similar but increasingly ill-defined dorsal projec-
tion near the distal margin. The distal margins, particularly of the basal segments,
are flaring so that they form a conspicuous socket for the next succeeding segment.

320 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

All the segments are longer than broad, except the basal three, and the fifth (or sixth)
is the longest.

There are 23 arms of which two are very small. The longest exceed 100 mm.
Dr. Clark said that in their ornamentation the arms are more like Hartlaub's fig. 9,
pi. 5 (second specimen from Martinique) than they are like the figures he gives for
var. ornata (to which he referred the specimen), but he was not at all clear as to how
much weight slight differences of ornamentation properly carry in Crinometra.

The difference between Hartlaub's Antedon brevipinna var. ornata and the second
specimen from Martinique (pi. 5, fig. 9) which he identified as Antedon granulifera is
not in the ornamentation, but hi the character of the IIBr series — 2 in ornata, 4(3+4)
hi granulifera. Dr. Clark does not mention the division series in his discussion.

Dr. Clark said that the pinnules of the specimen in hand are remarkable for the
very great width of some of the basal segments. Thus P6 is 6 mm. long with 10 seg-
ments of which the third is 0.75-0.80 mm. high and a trifle more than 1 mm. broad,
while the fourth is about as broad and is fully 1 mm. high; succeeding segments are
much narrower.

He remarked that it will be at once noted that these pinnules are utterly different
from Hartlaub's fig. 6, pi. 4, but they are apparently identical with those shown in the
photograph, fig. 4, pi. 12. He said "No doubt Hartlaub has at least two distinct species
confused under his 'variety ornatal' " Dr. Clark overlooked the fact that the genital
pinnules vary widely hi shape according to the state of development of the gonads.

He said that the arm fragments at hand (from station 9) agree perfectly in orna-
mentation and in pinnules with the whole specimen, and there is no doubt of their
identity.

Localities. — Albatross stations 2330, 2333; University of Iowa's Bahama. Expedition
stations 9, 16; Martinique.

Geographical range. — From northern Cuba to Martinique.

Bathymetrical range. — From 221 to 366 meters.

CRINOMETRA BREVIPINNA Tar. CORONATA (Hartlaub)

Antedon pourtalesi (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, pp. 54,

208, 209, 211, 212 (in key), 368, 379 (range).
Antedon brevipinna var. coronata HARTLAUB Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323

(in key), p. 345 (description; Blake stations 219, 241, 272), pi. 11, fig. 7.

Description. — Hartlaub said that a medium-sized specimen from Blake station 241
and another somewhat smaller but of similar habitus and of a similar reddish color from
Blake station 272 recall in the ornamentation of the lower brachials the first Martinique
specimen of granulvfera (see page 330). But the agreement is not so close as in the case
of the specimen described as var. spinosa. In addition to these specimens Hartlaub
described as a representative of var. coronata a specimen deviating somewhat from those
from Blake station 219 that Carpenter had designated as pourtalesi.

In the specimen from Blake station 241 the centrodorsal is highly arched and
slightly flattened dorsally. Only a small, somewhat excavated, bare dorsal pole is
present. The interradial processes are well developed. In the specimen from Blake
station 272 the centrodorsal is flatter with a more pointed dorsal pole so that its form
approaches the conical, and the interradial processes are not so well developed.

A MONOGRAPH OF THE EXISTING CRINOIDS 321

In the specimen from Blake station 241 the number of the pure white cirri is about
XXX, in that from Blake station 272 about XX. The segments, except for the first
three or four, are elongated. The cirri are entire only in the specimen from Blake
station 272, in which they have 18-20 segments of which the 8 outermost have processes
on the distal ends and the penultimate bears an opposing spine.

In the smaller specimen from Blake station 272 the radials, although withdrawn,
are visible, but they are almost entirely concealed in the specimen from Blake station
241. The IBri and IBr2 (axillaries) are relatively flat in both; there is a marked
synarthrial tubercle. The axillaries are sometimes pentagonal, sometimes more
rhombic, but in any case without a marked posterior process. The IIBrt in the IIBr
2 series is rather high and rectangular. In the specimen from Blake station 241 there
are 8 IIBr series of which six are 2 and only two are 4(3+4). In the smaller specimen
from Blake station 272 all five IIBr series preserved are 4(3 + 4). In addition to the
IIBr series, the specimen from Blake station 2 1 9 has one IIIBr2(l + 2) series. Here again
the variation in shape of the lower brachials can be seen, the first three being rectangular
with transverse articulations, followed by four or five bluntly wedge-shaped with
diagonal articulations, then two or three transverse articulations with one or two rec-
tangular brachials, followed by approximately triangular brachials with strongly diagonal
articulations. A similar condition is seen in the lower brachials of the specimen of
granulifera from Martinique.

According to Hartlaub these two specimens differ from the granulifera specimen
mentioned, and also from Charitometra basicurva, which has a similar brachial orna-
mentation, hi that the elements of the division series are not smooth but ornamented.
In the specimen from Blake station 241 there are small more or less sharp spines or
dentations which are arranged along the edges, usually in a single row. In the speci-
men from Blake station 272, which is smaller, this ornamentation is not so well devel-
oped, the dentations are smaller, and blunter, though the marginal dentation of the
ossicles is everywhere easily recognizable. On the IBri of this specimen the median
elevation is approximately in the form of a knob. It is not present hi the specimen
from Blake station 241. The ornamentation of the first 10 to 12 brachials consists of
a crown of more or less high, erect, sharp teeth or spines on the distal edge which are
typically developed especially in the smaller specimen from Blake station 272. In
contrast to the first Martinique specimen of granulifera the proximal border of the
brachials may also be ornamented with small spines or teeth; this feature is very
characteristically developed on the lower brachials of some arms of the specimen from
Blake station 241. After the tenth or twelfth the brachials are smooth and have
thickened and slightly crenulate distal borders.

Since hi both specimens only a small fraction of the arms originally present are
preserved — hi the smaller they are mostly broken off and hi the larger they are re-
generating— only limited statements can be made regarding the original arm numbers,
the distribution of the syzygies, and the outer pinnules. With the regenerates the
number of arms in the specimen from Blake station 241 is 19, and the number in that
from Blake station 272 is 15.

The sequence of the syzygies hi the two fairly well preserved arms of the speci-
men from Blake station 272, one being an original arm from a IBr axillary and the other
a regenerated arm from a IIBr axillary, is as follows. In the arm from a IBr axillary

843803—50 22

322 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

syzygies occur between brachials 3+4, 14+15, 22+23, 25+26, and 32+33. In the
arm arising from a IIBr axillary syzygies occur between brachials 1+2, 3+4, 18 + 19,
28+29, and 36+37. In the specimen from Blake station 241 there are three arms
arising from IIBr axillaries in which the first syzygy is between brachials 1+2 and the
second is between brachials 3+4. On an arm arising from a IBr axillary which bears
regenerated brachials from the epizygal of the second syzygial pair onward the syzygies
are between brachials 3+4, 4+5, 26 + 27, 35+36, 45+46, and 58 + 59.

In the specimen from Blake station 241 PI on arms arising from a IIBr axillary
is about 10 mm. long with about 20 segments of which the first six are broadened and
the third-sixth bear a typical hatchet-formed, or convex, keel. In the specimen from
Blake station 272 this hatchetlike carination is not evident. Here the corresponding
keels are straight and narrower. The pinnule inself is 7-8 mm. long with about 20
segments. The pinnules following become gradually shorter and the number of their
segments fewer. The pinnules of the middle of the arm may be observed only on
unregenerated arms in the specimen from Blake station 272. They are 4 mm. long
with 8-10 segments of which the two basal are short, the remainder elongated. Where
gonads are developed the third and fourth segments are broadened. In this variety
these pinnules resemble those of the first Martinique specimen of granulifera. Toward
the arm tips the pinnules of this specimen are twice as long and are composed of 14
segments which, with the exception of the first two, are very slender.

The ambulacral plating consists of prominent side and covering plates. The
sacculi are very small, on many pinnules not visible. In the specimen from Blake
station 241 the arms are about 90 mm. long, in that from Blake station 272 about 60
mm. long.

In alcohol the color of the specimen from Blake station 241 is gray, that of the
specimen from Blake station 272 white. In both the cirri are shining white. In the
specimen from Blake station 241 the division series are gray, in that from Blake station
272 almost white. The arms of both are light reddish gray, the pinnules and re-
generated arms white.

The third specimen, from Blake station 219, according to Hartlaub, is to be referred
to this variety in spite of some deviations. This is a cotype of Carpenter's Antedon
pourtalesi (see page 309), but it differs markedly from the holotype.

The form of the centrodorsal resembles that of the specimen from Blake station
241, except that here there are prominent interradial ridges that are only indicated in
that specimen; weaker radial ridges are also present so that the cirri stand in columns,
three to a column. This regular arrangement of the cirri is indicated in both the other
specimens.

The radials are only partially visible, near the interradial processes of the centro-
dorsal. All the IIBr series preserved are 2, and there are two IIIBr 2 and one IIIBr
4(3+4) series. The ornamentation of the division series, consisting of a high develop-
ment of the marginal frills of the ossicles as seen in the specimen from Blake station
241, is in general missing only here and there, small spines or dentations standing out
prominently along the edges of the ossicles. There is a median ridge on these ossicles,
but otherwise the dorsal surface is smooth. On a few of the elements of the IIBr series
there are already the stout spines that are so characteristic of the distal borders of the
brachials.

A MONOGRAPH OF THE EXISTING CRINOIDS 323

The ornamentation of the first 10 or 12 brachials is not so regular as in the specimen
from Blake station 272, and is in part composed of several pointed spines, which are
stouter than those on the specimen from Blake station 241.

The distribution of the syzygies agrees with that in the first two specimens. In
the two preserved arms arising from a IIBr axillary the first syzygy is between brachials
1+2 and the second is between brachials 4 + 5 or 6 + 7. Also on arms arising from
IIIBr axillaries there appears usually to be a syzygy between brachials 1 +2.

The pinnules, which are poorly preserved, appear not to differ significantly from
those of the two other specimens. The carination of PI is hatchetlike or convex as in
the specimen from Blake station 241.

The reddish color is not present in this specimen which is gray, the base darker,
the arms lighter.

The arms have an estimated length of 75 mm.

Localities.— Blake stations 219, 241, 272.

Geographical range. — Barbados, St. Lucia, and Carriacou (Grenadines).

Bathymetrical range. — From 139 to 298 meters.

Thermal range.— From 11.67° to 18.20° C.

CEINOMETKA BREVIPINNA var. ORNATA (Harllaub)

Antedon brevipinna var. ornata HARTLAUB. Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 323 (in
key), p. 348 (description; Blake, station 249), pi. 4, fig. 6, pi. 12, fig. 4.

Description. — A large and magnificent specimen with numerous stout and richly
ornamented arms, in spite of many deviations, was considered by Hartlaub as a further
development of the brevipinna type.

The centrodorsal is rather flat with a typical dark-colored bare dorsal pole which
is beset with fine tuberosities. The interradial processes are well developed. The cirri
are about XXXIII; only one cirrus with 15 segments is entire. In this the first two
segments are short, the remainder elongated, and an opposing spine is present.

The radials are wholly concealed. The IBi'i are unusually flat. The similarly
flat IBr2 (axillaries) are more rhombic than pentagonal, with a slight posterior process.
Of the 10 IIBr series present, five are 2, one is composed of a single axillary ossicle, and
four are 4(3 + 4). The ossicles are in general flat. The axillary is often of irregular
shape, with one side high and the other low. There are several IIIBr 2 series, one
IIIBr 1 series, and one IIIBr 2(1+2) series. Two IVBr 2 series are present.

There are 32 arms. In the shape of the lower brachials there is a double variation.
First, there are about three transverse articulations, then about six diagonal, then two
or three transverse, the remainder being diagonal. The shape of the brachials changes
in accordance with the direction of the articulations. Toward the arm tips the brachials
have a scalelike overlap.

The ornamentation differs from that of the two specimens described as var.
coronata in being more richly developed as a result of greater coarseness. On the IBr
series there is a slight granulation or tuberculation, only the distal edge of the IBr2
(axillaries) showing a dentation. Usually the IBr axillary has a ridgelike or sharply
tubercular median ornamentation. This is also present on the IIBr series in the shape
of one or several erect and usually sharp tubercles, though granules or coarse spines are
here and there present on the dorsal surface, especially on the sides. The distal borders

324 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

of the axillaries, sometimes also the proximal border, like the distal border of the IIBr2
(in IIBr 4[3+4] series) and the lateral borders of the IIBr, are everted and dentate.
The ornaments of the IIIBr series have already developed the entirely spiny or dentate
character. The ornamentation of the lower brachials of this specimen shows the Spinosa
type in its highest development. The brachials bristle with pointed spines and sharp
teeth that are sometimes single, sometimes more or less coalesced. Especially favored
are the distal edges of the brachials; particularly from the fourth to about the tenth
bracliial the surface of the brachials is beset with smaller teeth and spines. On syzygial
pairs there are only two transverse rows of spines, one directly beneath the other.
The distal limit of this ornamentation varies on different arms from the tenth to the
seventeenth brachial. On the surface of the brachials immediately following are found
only isolated and sometimes obsolescent granules; their distal ends are at first beset
with rather high spines which later become smaller and more sparse, and finally dis-
appear toward the arm tips.

The sequence of the syzygies is rather variable. In arms arising from a IIBr
axillary the first syzygy may be between brachials 1+2, followed by another between
brachials 4 + 5; or these two syzygies may be absent, in which case the first syzygy is
found between brachials 11 + 12 or 14 + 15. A syzygy from between brachials 19+20
to between brachials 23+24 appears to follow regularly, and the next follows at inter-
vals of from 6 to 9 muscular articulations. On arms arising from a IIIBr axillary the
first syzygy as a rule is between brachials 1+2, often followed by another between
brachials 3 +4. The syzygy between brachials 1 +2 is rarely absent, but if it is the first
syzygy is between brachials 3+4. The next syzygy, which is sometimes the second
and sometimes the third, is from between brachials 13 + 14 to between brachials 23+24,
and the distal intersyzygial interval is from 4 to 14, usually 7-10, muscular articulations.

PD is 15-17 mm. long and is composed of 30-40 short segments of which the first
8-12 are much broadened and are keeled into a hatchet-shaped edge on one side. PI
is 10-12 mm. long with about 30 segments of which the lowest 6-8, with the exception
of the two first, show the typical carination. The length of the lower pinnules appears
to vary, as on one arm Hartlaub found PI about 11 mm. long and P2 15 mm. long with
about 28 segments. In general the length of the following pinnules as far as P4 and
the number of their component segments decreases. P< is 8-10 mm. long with 15-20
segments. In the range of the ornamentation of the arms the keels of the first 2-4
pinnule segments are often beset with spines or teeth. The pinnules of the middle of
the arms, after the tenth brachial, are 6-7 mm. long with 10-12 segments of which the
two first are short and those following elongate. Where gonads are present the third
and fourth segments are markedly broadened. Toward the arm tips the pinnules be-
come more slender and their length and the number of component segments increases.
The distal pinnules are about 10 mm. long with up to 15 segments.

The ambulacral plating consists of prominent side and covering plates. The sac-
culi are of medium size and rather conspicuous. The disk is about 20 mm. in diameter
and is only slightly incised.

The arm length is estimated at 140 mm.

In alcohol the disk is gray-brown, the skeleton light gray. The centrodorsal is
somewhat darker than the other parts. Only the cirri are white.

Locality. — Blake station 249.

A MONOGRAPH OF THE EXISTING CRINOIDS 325

Geographical range. — Known only from off Grenada.
Bathymetrical range. — Known only from 479 meters.
Thermal range. — One record, 8.33° C.

CRINOMETRA BREVIPINNA vat. GRANULOSA (Hartlanb)

Antedon brevipinna var. granulosa HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 19)2, p. 323
(in key), p. 351 (description; Blake station 45), pi. 11, figs. 1, 2.

Description. — Hartlaub said that a specimen from Blake station 45 with an arm
length estimated at about 125 mm., together with a detached postradial series of similar
character from another individual, in their ornamentation recall the postradial series
of a specimen of granulifera from the same station, especially the larger of PourtaleV
type specimens. He said that this was especially remarkable because in this specimen,
in addition to the IIBr 2 series, there is one IIBr 4 series and one IIBr 3 series, in both
cases without syzygies. He remarked it is possible that, in spite of many deviations
from Pourtales' type specimen, this individual represents a transition form between
brevipinna and granulifera.

The centrodorsal is subhemispherical with a flat excavated bare dorsal pole.
The interradial processes are well developed. The number of cirrus sockets is about 40.

The cirri, except for a single slender one with 17 segments, are broken off. They
are apparently very slender, hi contrast to those of var. tuberosa.

The radials are not visible. The IBri are very flat, bowed downward in the middle.
The IBr2 (axillaries), also rather short, are rhombic; the proximal border is somewhat
convex, though without forming a typical posterior process, from the IBrt outward to the
fourth brachial on arms arising from a IBr axillary, or to the second brachial on arms
arising from a IIBr axillary. The IIBr series are usually 2; one is 4(3 + 4) and another
is 4, without a syzygy. Several ossicles are irregularly formed, or appear as if broken in
pieces. Of the IIIBr series, two are 2 and one is 4(3+4). On the additional postradial
series found with the specimen all the IIBr and IIIBr series are 2. The surface of all
the ossicles of the division series, as hi the case of Pourtales' type specimen of granuli-
fera, bears coarse and very flat granules; hi the median line there is a larger and some-
what higher granule, or a slightly raised median ridge. The borders of the ossicles
are smooth.

There are 20 arms, of which 3 arise from IBr axillaries. As far as the fourth or
sixth brachials the articulations are transverse. The brachials here are discoidal,
broader than long. Then follow four or five bluntly wedge-shaped brachials, then
usually two or three somewhat longer and approximately discoidal with transverse
articulations, after which the brachials again become wedge-shaped, and farther out
more triangular. The surface of the brachials as far as the fifteenth or seventeenth is
also granulated, but here the granules are smaller and lower than those on the division
series, and on many arms are more in the form of small teeth.

In arms arising from a IBr axillary the first syzygy is between brachials 3+4,
immediately followed by another between brachials 5+6. On arms arising from a
IIBr or IIIBr axillary the first syzygy is usually between brachials 1 + 2, the second
usually between brachials 3+4, the third from between brachials 6 + 7 to between
brachials 15+16, and the distal intersyzygial interval, so far as may be judged from
the few better preserved arms, is 4-16, usually 6-9, muscular articulations.

326 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

On one arm arising from a IBr axillary P! is 10 mm. long with 21 short seg-
ments; on another it is 15 mm. long with about 35 segments; thus P! is rather vari-
able. Only one, three-edged, PD with 30 segments is present; the first 12 to about 18
segments, except for the basal, are strikingly broad and keeled. In this pinnule about
six of the proximal segments are thick, strongly broadened, and at first narrowly,
but from the third or fourth onward more broadly, keeled. In this, as in other respects,
it resembles PD in the second Martinique specimen of granulifera, without being wholly
in agreement with it. PI on arms arising from IIBr or IIIBr axillaries is very variable,
in individual cases about 10 mm. long with about 20 segments. In general the pinnules
following decrease in length and in the number of their component segments to about
P4. The pinnules of the middle of the arm are unfortunately very poorly preserved;
a few uninjured ones are 4-6 mm. long with 12-14 segments, often only 9 or 10, of
which the two first are short, triangular, the next two or three broadened over the
gonads and quadrangular, and those following elongate. On the single postradial
series on which they may be made out the distal pinnules become longer again and,
except for the first two segments, are very slender, about 9 mm. long with 13-15
segments.

The ambulacra! plating consists of prominent side and covering plates. The
sacculi are rather large and conspicuous. The disk is about 12 mm. in diameter, dark
brown, and deeply incised.

In alcohol the centrodorsal is dark gray brown, the rest of the skeleton lighter and
gray.

Locality. — Blake station 45.

Geographical range. — Northwest of the Dry Tortugas, Florida.

Bathymetrical range. — Between 731 and 1,097 meters.

Thermal range. — One record, 5.0° C. (at 1,097 meters) ; this is undoubtedly too low.

CRINOMETRA BREVIPINNA Tar. GRANULIFERA (Pourtales)

[See vol. 1, pt. 2, figs. 304, 305, p. 223, fig. 674, p. 335.]

Antedon granulifera POTJRTALES, Bull. Mus. Comp. Zool., vol. 5, No. 8, 1878, p. 215 (description;
Blake station 45). — P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 241
(in key), p. 380 (Caribbean Islands; 101-120 fathoms [Blake stations 45 and 157]). — HARTLATJB
(in part), Mem. Mus. Conip. Zool., vol. 27, No. 4, 1912, p. 298 (redescriptiou ; Blake stations 34,
45, 101 [but not the second specimen from Martinique, which is gemmata]), pi. 1, figs. 24, 25, pi.
5, figs. 1, 2, 4, 6, 10-13, pi. 12, figs. 2, 6, 7.

Charitometra imbricata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 266 (new name for
Antedon granulifera P. H. Carpenter, [erroneously] supposed not of Pourtales; specimen with three
consecutive pinnules on the same side, with no locality given).

Crinometra granulifera A. H. CLARK, The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 40
(range). — H. L. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 15, No. 1, 1941, p. 9 (Atlantis stations
2999, 3303, 3465, 3478, 3482).

Description. — Hartlaub redescribed Antedon granulifera on the basis of two much
broken specimens and a detached disk from Blake station 45, apparently the type ma-
terial of Pourtales, and two very mediocre specimens with detached arms from Blake
station 34. The two better specimens together with various pieces of arms and a
calyx from off Martinique also regarded by Hartlaub as representing granulifera are
herein referred to var. pulchra.

A MONOGRAPH OF THE EXISTING CRINOIDS 327

Hartlaub said that Carpenter evidently had several specimens from the Blake
collection that he referred to granulifera besides Pourtales' types, and he believed that
he considered as representing granulifera the specimens that he (Hartlaub) described
under that name, although no label in Carpenter's hand was found anywhere.

Hartlaub remarked that his material showed to an extraordinary degree the great
variability of this form. He said that this variability is not confined alone to the out-
ward habitus or to the ornamentation, but affects also those features which ordinarily
show greater constancy, such as the distribution of the syzygies, the length of the
proximal pinnules, the relative visibility of the radials, and so forth, and in these cases
it is so extensive that at first it appeared to be impossible to give a specific diagnosis
that he could consider as of real value and reliability on the basis of the specimens
before him. Hartlaub considered it most practicable to give a detailed description of
the individuals from which an appreciation of the true specific characters may be
obtained.

Hartlaub noted that in a letter to him dated December, 1909, I had sent him some
critical remarks on the proofs of his plates 1-10, and he found that I had described as
new species several of the forms regarded by him as varieties of granulifera. Thus the
second individual from Martinique as shown on plate 5, figure 8, I identified as my
Crinometra imbricata, and the first specimen from Martinique as shown on plate 5,
figure 3, I identified with my C. pulchra. Hartlaub said he need only remark that he
held to his original opinion and hoped especially that his plate 12, which I did not see,
would serve to justify it.

In the two specimens from Blake station 45, which were part of Pourtales' original
material, the centrodorsal is dome-shaped, the bare dorsal pole with traces of cirrus
sockets. At the base of the centrodorsal are five small elevated interradial knobs.

The cirri are about XX, 15-20, from 8 to 23 mm. long. The three basal segments
are thick, short, and cylindrical, those following elongate, the outermost shorter again
and strongly compressed laterally. There are no dorsal spines, with the exception of
the feebly developed opposing spine, but the distal ends of the segments are slightly
overlapping.

The radials are short, though entirely visible, somewhat longer laterally than in
the median line, with a small knob in the middle of the dorsal surface; they are in close
contact laterally. The IBrj are somewhat longer than the radials; there is no note-
worthy elevation on the articulation with the IBr2 (axillaries) ; they are laterally in
contact. The IBr, (axillaries) are pentagonal, laterally as long as the IBri. The IIBr
series are either 2 or 4(3+4). In the smaller specimen there are three IIBr 2 and two
IIBr 4(3+4) series, in the larger five IIBr 4(3+4) series and one IIBr 2 series. In the
larger specimen the ossicles as far as the IIBr2 have rather sharply flattened sides; in
the smaller this feature at the best is only suggested. The IIIBr series are 2, though
according to Carpenter they are 2(1+2); Hartlaub said that following a IIBr 2 series
the two elements of the IIIBr series gave the impression of being united by muscular
articulation. The surface of all the ossicles of the division series in the larger specimen
is flat and coarsely granulated, and in the middle of the dorsal surface there is dis-
tinguishable a stouter granule resembling that on the radials. This alone is present
on the smaller specimen, the rest of the ossicles being smooth. There are no Bynarthrial
tubercules.

328 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The larger specimen has 21, the smaller 19, rather slender arms. The first brachials
are in close lateral apposition. The lower approximately discoidal brachials as far as
about the eleventh in the larger specimen have strongly produced distal ends which are
partially beset with smooth sharp spines. On some arms these brachials are markedly
saddle-shaped (that is, centrally constricted) and spiny, this feature being much less
developed on others. Quite characteristic it is for their surface to have irregular
cavities, and as a result a grooved or furrowed appearance. A central small knob may
be distinguished on all the brachials except the more saddle-shaped ones with a spiny
edge. These small knobs form a continuous row as far as the radials. The distal edges
of the brachials often have a spine or process on each side. The proximal brachials of
the small specimen are much smoother; only here and there may there be seen a pro-
nounced grooving of the surface and a small knob in the middle. The brachials follow-
ing are triangular with arched distal ends, and have smooth surfaces. Toward the
arm tips they have a tilelike overlap, and the distal edge here is slightly convex.

In arms arising from a IBraxillary the first syzygy is between brachials 3+4, in arms
arising from a IIBr or IIIBr axillary between brachials 1+2, this being often followed
by one between brachials 3+4 or between brachials 4 + 5. The next syzygy is usually
at about the twenty-first brachial, those following often at intervals of 9 or 10 muscular
articulations, and farther out at intervals of about 6 muscular articulations. In the
smaller specimen, in arms arising from a IIIBr axillary the syzygies are at shorter
intervals, for instance between brachials 1+2, 4 + 5, 17+18, 23+24, 29+30, and
34+35; or between brachials 1+2, 6 + 7, 15 + 16, 21+22, and 27+28; an arm arising
from a IBr axillary has the first syzygy between brachials 3+4, the next between
brachials 6 + 7, and the third between brachials 22+23.

The lowest pinnule in the larger specimen is on the IIBr2 if the division series are
4(3+4), and there is always a pinnule on the second brachial. Only a PI is preserved
entire. It is 12 mm. long with 30 short segments of which the lower are broad and
carinate. P2 is markedly shorter and has only 17 segments. The pinnule following on
the same arm is not complete. P4 is 5 mm. long with about 12 segments. The lower
segments of all these pinnules are broadened, but there is no clearly marked carination.
On other arms the lower segments of these same pinnules are sharply carinate, which
appears to be the general rule. The distal pinnules have usually 13 segments, most of
which are elongate and cylindrical. In the younger specimen a carination of the lower
pinnules is scarcely present. On the larger it reaches to about the sixteenth brachial.

The ambulacra of the pinnules are provided with side and covering plates, and with
numerous inconspicuous sacculi. The disk is somewhat incised. In the larger speci-
men it is scarcely 10 mm. in diameter, in the smaller 6 mm. It is thickly beset with
calcareous granules which are rounded or elongate and are mostly not in contact with
each other.

The larger has the arms with an estimated length of 100 mm., the smaller of
60 mm.

In alcohol the skeleton is brownish white, the disk and soft parts of the arms dark
brown.

Hartlaub pointed out that Pourtales' original description gave the number of arms
as 20, with a spread of 200 to 230 mm. (or an arm length of 100 to 115 mm.). It differs
from his description in stating that the radials are entirely concealed, and that at about

A MONOGRAPH OF THE EXISTING CRENOIDS 329

the middle of the arm the brachials are frequently, though not always, ornamented
with beadlike tubercles of which the middle one is the largest. Pourtales said that the
first pinnule is the longest and very broad on the first brachial, by which he probably
meant the epizygal of the first syzygial pair.

Hartlaub remarked the absence of any statement regarding the number or state
of preservation of PourtaleV specimens. In view of Hartlaub's observations the most
striking deviation is that the ornamentaoion of the arms is confined to the middle,
while he found it developed only on the arm bases. Pourtales' statements regarding
the proximal border of the saddle-formed brachials are in complete agreement with his
observations.

The differences between Pourtales' original description and Hartlaub's redescrip-
tion are probably explained by a specimen in the Museum of Comparative Zoology
(No. 267) from Blake station 45 which is labeled "Antedon granulifera" and is probably
the one on which Pourtales' original description was mainly based; it was not seen by
Hartlaub.

In this specimen the longest cirrus has 18 segments and is 33 mm. long and rather
slender. The IIBr series are of 4 ossicles of which the two outer are not united by
syzygy. The division series and arm bases are perfectly smooth dorsally, rather strongly
convex, and sharply flattened laterally. The earlier brachials have prominently and
rather abruptly everted ends, and usually a more or less prominent tubercle in the middle
of the distal edge.

Both the specimens from Blake station 34 are very poorly preserved. Almost all
the arms are broken off close to the base. The larger lacks the disk. This specimen
shows the closest agreement with that from Blake station 45, while the smaller is
remarkable for its more strongly spiny ornamentation.

The larger specimen has well preserved cirri, one of which exceeds the others,
reaching a length of 35 mm. Especially to be noticed, according to Hartlaub, is the
fact that in this specimen the small prominences in the middle of the ossicles of the
division series are not knoblike, but take the form of feeble elongate ridges. This type
of ridge is found highly developed in a specimen from Montserrat (Blake station 157)
that Carpenter has apparently referred to granulifera but which Hartlaub described
under the name of Antedon angusticalyx (see var. angusta, p. 335). There is a single well
preserved PI. It is about 12 mm. long and is composed of 25 segments which from the
ninth onward are elongate. The lowest segments, like those on the two following
pinnules, are carinate. The pinnules immediately following have more uniform,
strongly broadened, segments. The elongate form of the pinnule segments forms a
very noteworthy contrast to the conditions in the specimen from Blake station 45.
Hartlaub remarked that if we wish to form a correct estimate of the range of forms in
such a variable type as granulifera we must present the small individual variations
with the greatest care.

In the larger specimen from Blake station 45 Hartlaub noted on individual arms
saddle-shaped brachials with spiny ends. In the smaller specimen from Blake station
34, of which the arms are about 75 mm. long, he found the distal ends of all the ossicles
from the IBr axillary to about the thirteenth brachial beset with small, stout, erect
spines. Isolated small spines are also found on the dorsal surface. On the ossicles
of the division series there is a small knoblike elevation in the middle. The proximal

330 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ends of the ossicles as a rule are not spiny. A saddle-shaped concavity of the dorsal
surface is nowhere present.

Hartlaub said that this specimen shows a transition to the one from Martinique.
The feature of the spiny edges, which in the specimen from Blake station 45 is only to
be noticed in traces here and there, is so much further developed in the Martinique
specimen that it totally alters the general appearance. This Martinique specimen is
herein regarded as belonging to var. gemmata. (see page 318).

In the larger specimen from Blake station 34 Hartlaub counted seven IIIBr series,
but apparently more were originally present. The number of arms he estimated as at
least 30. The radials are only slightly visible in the interradial angles. Of the IIBr
series, one is 2 and one is 4(3 + 4).

The smaller specimen from Blake station 34 had apparently about 20 arms. Two
of the IIBr series are 2. There are no IIIBr series. The radials are wholly visible.
PD is predominantly flattened laterally. The cirri are strikingly short.

The best specimens, according to Hartlaub, were two from off Martinique col-
lected by Captain Cole apparently when on the cable repair ship Investigator. They
far exceed those from Blake stations 45 and 34 previously described, and because of
the relatively good state of preservation of their arms permit of a fairly close estimate
of the arm length. So different are they that they show in its highest development
each feature of the ornamentation which in the others, perhaps because of then- younger
age, is only indicated. The second of these specimens is described under var. gemmata
(see page 319).

The first specimen from Martinique, according to Hartlaub, shows a striking
similarity to Charitometra basicurva in the ornamentation of the lower brachials. These
ossicles are strongly saddle-shaped, and their greatly produced edges are beset with
sharp, stout, and erect spines. The characteristic granulation which appears on the
surface of the division series in the first described specimen from Blake station 45 is
here entirely lacking.

There are 21 arms about 140 mm. long. One of the IIBr series is 2. The arms
have syzygies between brachials 1+2 and also between brachials 3+4. One IIIBr 2
series follows a IIBr 4(3+4) series, developed internally.

The radials are slightly visible here and there. The IBri are short; their proximal
border is rather strongly convex and laterally somewhat notched. Such notches,
interrupted by small convexities, were found more extensively in the two specimens
from Blake station 157 determined as Antedon angusticalyx by Hartlaub (=var. angusta,
page 335). The lateral borders of the IBri are somewhat broadened, this broadening
resulting in part from an incision, often very strong, by the IBr axillary. A quite
similar relationship exists between the IIBi'i and IIBr2.

The small pinnules of the ninth-eleventh brachials, which are about 5 mm. long,
show a very marked broadening of the third-fifth segments, especially of the fourth.
The lowest pinnules are not visible because of the very close apposition of the arm bases.

This specimen is the stoutest of all those seen by Hartlaub, and the estimate of
an expanse of 380 mm. (an arm length of 190 mm.) is certainly not too high.

Another specimen from Martinique was apparently utilized by Carpenter for a
preparation of the calyx. The five radials, separated from the calyx, are fairly well
preserved.

A MONOGRAPH OF THE EXISTING CRINOIDS 331

This specimen stands out from the others in that there is no conspicuous contrast
between the proximal and more distal brachials in respect to conspicuous ornamentation.
The lower brachials are rather strongly saddle-shaped, but their dorsal surface is
smooth, and their distal ends are not beset with erect spines but are simply dentate
with sharp recumbent points. The arms are very slender and long. Long, slender,
and very flexible arms, according to Hartlaub, appear to be especially characteristic of
var. granulifera.

The sequence of the syzygies agrees with that of the second specimen from Mar-
tinique, herein referred to var. gemmata (see page 319). On several arms the second
syzygy follows the first after a few brachials; for instance, on one arm it is between
brachials 6 + 7, on another between brachials 10 + 11.

PD resembles the same pinnule in the smaller specimen from Montserrat (Blake
station 157) that Hartlaub referred to angusticalyx, (=var. angmta, p. 335). The
basal segments of the pinnules are broad, but from about the sixth onward they abruptly
become slender.

Summarizing the significant features held in common by the six specimens that
he referred to granulifera, Hartlaub listed these as: The form of the centrodorsal; the
number and form of the cirri and of their segments; the occurrence exclusively or
mainly of IIBr 4(3+4) series; short segments in the division series and arms; the
position of the first brachial syzygy between brachials 1+2 in arms arising from a
IIBr series; cariuate proximal pinnules with short broad segments; and restriction of
the brachial ornamentation to the arm bases.

The specimens referred to imbricata may be described as follows. The centrodor-
sal is hemispherical bearing 10 or 15 usually veiy definite columns of cirrus sockets;
the bare polar area is comparatively small.

The cirri are XXV-XXX, 17-23 (usually about 20), from 25 to 30 mm. long, and
are comparatively slender. The first four segments are short, the fourth is about as
long as broad, and the remainder are about half again as long as broad; the distal
ends are somewhat prominent and overlap slightly dorsally.

The ends of the basal rays are visible as rounded tubercles in the angles of the
calyx.

The radials are concealed, or partially visible as small tubercles on either side of
the basal tubercles. The IBi'i are very short with the proximal border convex. The
IBrj (axillaries) are very broad and low, about three times as broad as long. The
IIBr series are 4(3 + 4) and are very short. The IIIBr series are 2(1+2), internally
developed in 1,2,2,1 order. The distal angles of all the axillaries are remarkably low.
The division series and first five brachials are in close lateral apposition and are sharply
flattened laterally. The outer side of each postradial series is separated slightly from
that of the postradial series adjoining by the prominent dorsal carination of PD, the
dorsal portion of PD being partially visible between the rays.

There are 18-25 (usually about 20) arms about 160 mm. long. The arms are
slender and of approximately uniform width. The first four brachials are very short
and discoidnl; the next four or five are rectangular, those following becoming trian-
gular, about as long as broad, and remaining very uniform to the arm tips. The
edges of the elements of the division series and of the first four brachials are smooth,

332 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

those of the brachials following strongly overlapping. There is no trace of carination
or other surface ornamentation. The arms are rather sharply compressed laterally in
the basal half.

Syzygies occur between brachials 1+2 and 3+4, again from between brachials
7+8 to between brachials 13+14, and distally at intervals of 5-9 (usually 6 or 7)
muscular articulations.

PD is 11 mm. long with 35 or more short segments of which the basal 7 or 8 have
broad dorsal keels which gradually die away distally, though the pinnule is sharply
carinate to the tip. The pinnule is broad and much flattened in the basal half, then
becomes gradually narrower, ending in a slender and delicate tip. PI is similar but
about 1 mm. shorter with about 25 segments of which the distal are proportionately
longer and somewhat broader. P2 is 8 mm. long with about 20 segments which are
about as long as broad; the pinnule tapers evenly, the basal segments being very
slightly, when at all, carinate. P3 is similar to P2 but rather shorter with larger seg-
ments. The pinnules following are shorter still and have the third-fifth segments
laterally broadened, protecting the gonads. Distally the pinnules gradually increase
in length, the distal pinnules being 11-12 mm. long with about 22 segments of which
the first is short, the second is almost triangular, and those following are about half
again as long as broad; all have prominent distal edges.

The color in alcohol is yellowish white.

Two specimens from Albatross station 2154 described (in manuscript) under the
name inornata seem to belong here. The centrodorsal is flattened hemispherical with
the small bare polar area more or less rugose. The cirrus sockets are arranged in two
irregular rows, with a tendency toward two columns.

The cirri are XX, 20, 30 mm. long, and are rather slender. The first segment is
short, the second is twice as broad as long, the third is nearly as long as broad, and
those following increase in length to the sixth which, with the remainder, is somewhat
over twice as long as broad. The penultimate segment is slightly less in width than
those preceding, though of the same proportions. The outermost six or seven segments
have the median portion of the distal dorsal edge slightly thickened ; the distal ends of
all the segments are slightly and gradually enlarged. The opposing spine is represented
by a small terminally situated tubercle directed obliquely forward. The terminal
claw is about two-thirds the length of the penultimate segment, moderately slender
and evenly curved.

The ends of the basal rays are visible as prominent strongly rounded tubercles in
the angles of the calyx.

The radials are just visible beyond the rim of the centrodorsal. The IBri are
short, about four times as broad as long. The IBr2 (axillaries) are broadly pentagonal,
three times as broad as long, with the lateral borders as long as those of the IBri. The
IIBr series are 4(3 + 4). The IIIBr series are 2, though seldom present. The division
series are moderately and evenly convex dorsally, in close apposition and sharply
flattened laterally. PD is not visible exteriorly.

The 18 or 19 arms are about 100 mm. long and resemble those of the specimens
described as imbricata. The first twelve brachials are flattened laterally. The arms
are evenly rounded dorsally, without ornamentation. On the fifth or sixth the brachials
begin to develop overlapping distal ends, which soon become prominent.

A MONOGRAPH OF THE EXISTING CRINOIDS 333

The pinnules resemble those of the specimens described under imbricata, the
lower being strongly carinate.

The disk is completely covered with a pavement of very small plates. Side and
covering plates are well developed along the brachial and pinnule ambulacra.

The color in alcohol is white, the division series and arm bases as far as the third
brachial brownish.

Hartlaub described the skeletal elements of the calyx from a preparation consisting
of the centrodorsal and radial pentagon made by Carpenter which he found in a special
vial with the Martinique specimens. This description by Hartlaub should be compared
with the description of the centrodorsal and radial articular faces of Crinometra brev-
ipinna var. insculpta given in Part 2, pp. 48, 49, figs. 76, 77, p. 53.

Hartlaub says that the ventral surface of the centrodorsal is rather sharply pen-
tagonal, in good agreement with that of Perissometra inaequalis as figured by Carpenter.
The radial depressions are more or less sharply triangular, because the raised borders
of the basal grooves in part come into contact with each other at the entrance to the
central cavity of the centrodorsal. The circumference of the entrance to the central
cavity is sharply pentagonal.

The dorsal surface of the radial pentagon shows a well developed basal star. The
inner ends of the rays are united with the rosette by ring-shaped bridges; the sharply
pointed outer ends reach to the border of the radial pentagon. The rays of the basal
star are three-edged; inwardly they are in broad union with the rosette. With sufficient
treatment with caustic potash it is possible to isolate the basal rays with the rosette.
The isolated basal rays show on their inner end two perforations — the nerve canals.
All these features correspond in general to the same features in Perissometra angusticalyx
and in P. inaequalis.

But considerable differences from P. angusticalyx and P. inaequalis are shown in
the ornamentation of the outer articular face of the radials. Especially striking,
according to Hartlaub, is the absence of a median ridge separating the two muscular
fossae. This is present in most endocylic comatulids, and also in Perissometra angusti-
calyx and P. inaequalis. Instead of this, there is, as in the Comasteridae, a median
groove that begins between the interarticular ligament fossae and farther out broadens
into an unpaired muscular fossa. This muscular fossa, in contrast to the conditions
in Perissometra angusticalyx and P. inaequalis, is not bordered by a sharp ridge but is
separated from the two small interarticular ligament fossae by a broad elevation which
in places is obscure. On the other hand, the dorsal ligament fossa lying below the
opening of the radial nerve canal is large and well developed, as in Perissometra inae-
qualis. The angle of inclination of the joint face is moderate and less strong than in
P. angusticalyx, and in P. inaequalis. Finally, the dorsal surface of the radial pentagon
has approximately the same size as the ventral surface of the centrodorsal. In this
respect Hartlaub points out that there is agreement with P. inaequalis, while in the
specimen of P. angusticalyx figured by Carpenter the ventral surface of the centro-
dorsal is larger than the dorsal surface of the radial pentagon. Hartlaub said that in
general it should be noted that as yet it has not been determined to what degree of
variation the relation between the radial pentagon and the basal star is subject, and
therefore to what degree slight deviations in this region are of systematic significance.

334 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The preparation figured by Hartlaub certainly is not normal; possibly it had
become partially decalcified.

Localities. — Blake stations 34, 45, 101, 157; Investigator, Martinique; Albatross
stations 2327, 2319-2350; Caroline stations 43, 102; Atlantis stations 2999, 3303, 3465,
3478, 3482; "Caribbean Islands, 185-219 meters" (Blake stations 45 and 157) (Car-
penter).

Geographical range. — From the Yucatan Bank, southern Florida, and Cuba to
Martinique.

Bathymetrical range. — From 185 to 475 meters.

Thermal range. — One record, 16.53° C.

Remarks. — Dr. H. L. Clark said that the 15 specimens of granulifera secured by
the Atlantis were compared with Pourtales' type (M. C. Z., 267) and there is no doubt
of their identity. The only noticeable difference is that in the type the distal cirrus
segments are distally conspicuously wider than proximally, while in the Atlantis
material the projection of the lower (i. e., dorsal) distal margin is not so conspicuous.
But the Atlantis specimens show some diversity in this detail. The type has the
arms about 100 mm. long; several of the Atlantis specimens are larger, with arms 125-
150 mm. long. The type still retains a distinct dull purplish brown color, while the
Atlantis specimens are much more nearly white, especially when dry.

CRINOMETRA BREVIPINNA Tar. PULCHRA A. H. Clark

PLATE 30, FIGURE 91
[See also vol. 1, pt. 2, fig. 682, p. 338.]

Crinoniftra pnlchra A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 644 (description; Albatross
stations 2319-2350); U. S. Nat. Mus. Bull. 82, vol. 1, pt. 2, 1921, fig. 682, p. 338.

Description. — The centrodorsal is thick-discoidal, the sides more or less convergent
distally, with the bare polar area 3-5 mm. in diameter and more or less tubercular.
The cirrus sockets are arranged in three very irregular marginal rows.

The cirri are XX-XXIV, 18-20, from 30-40 mm. long, and moderately slender.
The first segment is very short, the second is longer, the third is longer than the second,
the fourth is rather more than twice as broad as long, and the remainder are approxi-
mately equal, nearly or quite half again as long as broad. The penultimate segment
is twice as long as broad, somewhat less in width than those preceding. The cirri are
slightly compressed in the distal half. The distal ends of the segments are slightly
enlarged, and in the distal third there is a slight enlargement of the distal dorsal edge.
The opposing spine is represented by a small blunt tubercle terminally situated and
directed obliquely forward. The terminal claw is short, about two-thirds as long as
the penultimate segment, stout and strongly curved.

The ends of the basal rays are visible as rather large tubercles in the angles
of the calyx.

The radials are entirely concealed, or at most form a gablelike ridge over the
ends of the basal rays. The IBr! are very short, chevron shaped or crescentic,
or entirely concealed. The IBr2 (axillaries) are large, rhombic, from half again to twice
as broad as long; the edges all around are prominent, and there is a moderate rounded
median carination. The IIBr series are 2, with the first element very short and the
axillary about twice as broad as long and rhombic. The IIIBr series are 2, similar to

A MONOGRAPH OF THE EXISTING CRINOIDS 335

the IIBr scries, developed interiorly in 1,2,2.1 order. The division series are perfectly
smooth dorsally and are in close apposition all around the calyx; the edges of the com-
ponent elements are slightly prominent, and the axillaries have a slight broadly rounded
median ridge, most pronounced on the first. One specimen has one IIBr series and one

HIBr series 4(3 +4).

The 30 arms are 150 mm. long and resemble, except in ornamentation, those of
related forms. After the third or fourth the brachials develop strongly overlapping
distal ends the middle of which is swollen into a broad tubercle which may extend
proximally to the lower edge. This feature disappears after about the thirtieth brachial.

PI is 11 mm. long with 30 segments, evenly tapering and becoming slender and
flagellate distally; the basal segments are about four times as broad as long, the outer
about as long as broad. P2 is of the same length as Pj and similar to it, but slightly
more slender. P3 is 9 mm. long and similar to P2. P4 is 9 mm. long, very slightly
stouter basally than P3. The pinnules following become gradually shorter with fewer
segments of which the basal become gradually more expanded. P8 is 7 mm. long with
15 segments of which the third, fourth, and fifth are much broadened and the sixth is
trapezoidal, the pinnule from this point onward being slender with the segments about
twice as long as broad. The pinnules following gradually decrease in length, P18 being
4 mm. long with about 12 segments of which the third-fifth are broadened and those
following are somewhat longer than broad. From this point onward the pinnules
gradually lose the expansion of the proximal segments and very slowly become more
slender and increase in length. The distal pinnules are 7 mm. long. The gonads
first appear on P6 and rapidly increase in size, becoming large and semicircular in pro-
file, laterally compressed, protected by the expansion of the pinnule segments and
ventrally by the development of a pavement of perisomic plates. They disappear at
about the end of the proximal third of the arms.

The disk is completely covered by a pavement of very small granular plates. Side
and covering plates are strongly developed along the ambulacra! grooves.

The color in alcohol is yellowish white, the division series and arm bases as far
as the second brachials dark brown.

Localities. — Albatross stations 2154, 2319-2350; Caroline station 43; Atlantis
station 3326.

Geographical range. — From northern Cuba to Puerto Rico.

Bathymetrical range.— From 484 (?439) to 567 meters.

Thermal range. — One record, 15.33° C.

Remarks. — Dr. H. L. Clark wrote that a small comatulid 10 mm. through the calyx
with arms about 90-100 mm. long dredged by the Atlantis at station 3326 looks like a
young Crinometra, but is clearly neither granulijera nor wsculpta. He said that I had
identified it for him as a young specimen of pulchra.

CRINOMETRA BREVIPINNA Tar. ANGUSTA, Tar. nov.

Anledon anguslicalyx (not of P. H. Carpenter, 1888) HARTLAUB, Mem. Mus. Comp. Zool., vol. 27,
No. 4, 1912, p. 287 (description of two specimens from Blake station 157), pi. 4, figs. 3, 4, pi. 12,
fig. 9, pi. 13, fig. 2.

Description. — The larger specimen from Blake station 157 described by Hartlaub
under the name of Antedon angusticalyx has the centrodorsal dome-shaped with strongly
developed interradial ridges and processes. The bare dorsal pole bears a few spines.

336 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XXI, 15-17. The first three segments are short, those following
elongate. The longest are the fifth, sixth, and seventh, which are about 2 mm. in
length. The profile of the dorsal edge of the cirri is proximally smooth but distally
somewhat serrate, as in the distal portion the surface of the segments is somewhat
produced at the distal end. The penultimate segment bears an opposing spine.

The radials are not visible. The IBrj are short; the proximal border has four
rounded processes, two lateral above the interradial processes of the centrodorsal and
two median above the border of two cirrus bases; the distal edge is deeply incised by
the proximal process of the axillary. On the dorsal surface there is a moderately sharp
median elevation. Laterally the IBrj are in close contact. The IBr2 (axillaries) , more
rhombic than pentagonal, show a strong proximal process incising the IBr] which on the
surface of the axillaries is sharpened in the form of a keel reaching its highest point
on the synarthrial tubercle which it forms with the IBr^ The axillaries are laterally
free and have sharply flattened sides. All the 10 IIBr series are 4(3+4). The IIBr2
has a proximally directed dorsal process which incises the distal edge of the IIBr! and
forms the summit of a second synarthrial tubercle. The IIBr series have sharply
flattened sides. There is a single IIIBr 2(1+2) series.

There are 21 arms about 150 mm. long (Hartlaub inadvertently gave the expanse
as 30 mm. instead of 30 cm.). Only the two or three earliest brachials are rectangular;
the second is somewhat shorter than the first, broader than long. The brachials then
become bluntly wedge-shaped, then gradually triangular, as broad as long, toward the
tips of the arms bluntly wedge-shaped again and at the same time longer.

The first syzygy is between brachials 1 +2 except on a single arm arising from a
IIBr axillary, on which it is between brachials 29+30. The position of the second
syzygy is variable. Hartlaub found it between brachials 26+27, 31+32, 34+35,
35+36, and 42+43. Two especially well preserved arms arising from a IIBr axillary
show the disposition of the following syzygies, which occur at very varied intervals.
In one the second syzygy is between brachials 42+43, those following between brachials
53+54, 61+62, 66+67, 74+75, 86+87, 96 + 97, 102 + 103, and 123 + 124. In the
other the second syzygy is between brachials 26 + 27 and those following are between
brachials 43+44, 52 + 53, 61 + 62, 68 + 69, 77+78, 99 + 100, 118 + 119, 127 + 128, and
132 + 133.

PD is 11 mm. long with about 30 segments of which the first four or five are some-
what stalked and broadened, though not strikingly differentiated from those following.
The succeeding pinnules are 6-7 mm. long with 15-18 segments of which the two first,
as in all the following pinnides, are short. P3 bears a prominent gonad. The pinnule
segments over the gonad are always broadened. The length of the genital pinnules
varies. They are usually 5-6 mm. long with 9-14 segments. Distally the length of the
genital pinnules appears gradually to decrease, but this cannot be determined with
certainty because of the poor state of preservation. At about the twenty-eighth
brachial the pinnules with prominent gonads stop. From about the thirty-sixth bra-
chial, where they measure about 5 mm. in length, the pinnules increase in length again.
In the distal third of the arms they are about 8 mm. long.

The disk is 12 mm. in diameter, rather deeply incised. According to Hartlaub it
shows the ambulacral plating and ornamentation of angusticalyx as given in Car-
penter's figures.

A MONOGRAPH OF THE EXISTING CRINOIDS 337

In alcohol the skeleton is pure white, the disk brownish white.

In the second and smaller specimen, which is only indifferently preserved, the
centrodorsal is more flattened than in the larger. The dorsal pole is free of cirri,
smooth, and deeply excavated. Interradial ridges are present, though strongly pro-
duced only in one place. Interradial processes are well developed.

The cirri are XXI; none of them are preserved.

The radials are short, though always visible. The IBri are only slightly incised
on the distal border; they are in close lateral apposition. The IBr2 (axillaries) have
only a weak posterior process. There is no ridgelike elevation of the dorsal surface of
the IBr series, and the synarthrial tubercle is not so strongly developed. The IIBr
series are more procumbent than in the larger specimen. The posterior process of the
IBr2 is weak, and a synarthrial tubercle is not present as it is in the larger individual.
The sides of the IIBr series are sharply flattened. Most of the IIBr series are 4(3+4),
but one is 2. On the IIBr2 of another postradial series of which the axillary is lacking
an arm has arisen through regeneration in which the first syzygy is not between brachials
1+2 but between brachials 31+32, the next being between brachials 53+54. There
are no IIIBr series.

The 19 arms are estimated as 125 mm. long. They are smooth, as in the larger
specimen. The first syzygy is between brachials 1+2. As in the larger specimen
the second brachial is shorter than the first, and moreover lies somewhat deeper.
The second syzygy is between brachials 28+29 and brachials 39+40, as in the larger
specimen. Three poorly preserved arms show the spacing of further syzygies. On
one arm syzygies occur between brachials 34+35, 51+52, and 59+60; on another
between brachials 39+40 and 52 + 53; and on the third between brachials 33 + 34
and 54 + 55. The interval between the second and third syzygies is therefore from
13 to 21 muscular articulations.

PD is about 8 mm. long with about 21 segments of which the first five or six are
large, broad, and stalked, those succeeding more or less suddenly slender and elongate.
Thus there is in general a basal broader section which is distinct from a more slender
flagellate outer section, a feature that also appears in the third Martinique specimen of
granulifera (see page 330). This difference is always greater than in the large specimen.
PI is shorter, 5-6 mm. long. The contrast between the broad basal and flagellate
outer sections has here already disappeared. The length of the pinnules following
decreases. Those immediately succeeding are about 3 mm. long; those in the middle
of the arms are 3^1 mm. long; these latter have, as in the larger specimen, two short
basal segments followed by 6 or 7 elongate ones. The gonads are slightly developed,
and the pinnule segments over them are, in relative fashion, modified as in the larger
specimen.

The disk is 8 mm. in diameter, less deeply incised than in the other specimen.

In alcohol the skeleton from the centrodorsal to the first brachials inclusive is
brownish white, the arms pure white. The disk is brownish white.

Hartlaub said that since the two specimens. do not in all their features agree
either with Perissometra angusticalyx or with P. inaequalis, and the larger specimen is
more like P. angusticalyx, while the smaller is more like P. inaequalis, it would be
natural to describe one as a variety of P. angusticalyx, the other as a variety of P.
inaequalis. He did not do this because he considered that these two species are poorly

338 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

established, and so he placed them under P. angusticalyx, which was the first described
by Carpenter. He said it is remarkable that Carpenter, after he had described these
two species at the same time, did not refer these specimens to one of them, but to
granuli/era Pourtales, for which different specific characters hold good. This cir-
cumstance indicates, according to Hartlaub, that angusticalyx and inaequalis belong
to the extremely variable species granulifera Pourtales. But Hartlaub admitted that
the material available to him was not sufficient to admit of a definite opinion.

Hartlaub noted that correlated with other features are the relationships of the
individual skeletal pieces of the calyx of inaequalis and angusticalyx as described and
figured by Carpenter.

The form of the centrodorsal, as far as the exterior is concerned, has been described.
In regard to the relative size relations of the centrodorsal and the radial pentagon the
smaller specimen, because of the visibility of the radials, agrees more with inaequalis.
The remaining differences between angusticalyx and inaequalis are, judging from
Carpenter's figures, not too significant, according to Hartlaub. In view of these figures,
the ornamentation of the articular faces of the radials show insignificant differences.
The muscular fossae in angusticalyx are smooth, in inaequalis ornamented with convex
ridges. In both the median (vertical) ridge, and also the lateral ridges separating the
muscular and interarticular ligament fossae are in agreement. The dorsal ligament
fossa, because of the greater size of the radials in inaegualis, seems to be more consider-
able than in angusticalyx. The differences in the ventral surface of the centrodorsal in
the two forms is trivial, those between the rosettes, according to Hartlaub, more
significant. In Hartlaub's opinion Carpenter gave too much weight to the differences
in the calyces of these two species. He remarked that in Carpenter's figures a complete
covering of the centrodorsal by the radial pentagon is not shown, and, further, he does
not understand how the comparison of individuals of different ages can be significant
for the differentiation of the species.

Hartlaub closed his account of what he called Antedon angusticalyx from Blake
station 157 with a few remarks on geographical distribution. He said that Carpenter's
material of angusticalyx consisted of several specimens that had been dredged off the
Meangis Islands, between the Moluccas and the Philippines. The material of inaequalis
came from the neighborhood of the Kermadec Islands about 8° northnortheast of New
Zealand, and also from the neighborhood of Kandavu, Fiji. He said that both species
were heretofore known as Pacific forms, but he remarked that in contrast to this it is of
interest that his material is Atlantic, from the Caribbean Sea, and noted that this is not
without parallel in the genus Antedon (in the old sense), for, as an example, A. (Tropio-
metra) carinata is found at St. Lucia in the Caribbean Sea and has also been dredged in
the Atlantic and Indian Oceans, as well as on the Pacific coast of America (but see
Part4b, pp. 319-323).

Locality. — Blake station 157.

Geographical range. — Known only from off Montserrat.

Bathymetrical range. — Known only from 219 meters.

A MONOGRAPH OF THE EXISTING CRINOIDS 339

DETAILS OF THE LOCALITIES WHERE CRINOMETRA BREVIPINNA AND ITS VARIETIES HAVE

BEEN DREDGED

Atlantis station 2950; Bahamas, south of Great Bahama Island (lat. 26°14' N.,
long. 78°43' W.); 521 meters; February 3, 1938 [H. L. Clark, 1941].

Blake station 34; north of the Yucatan Bank (lat. 23°52'00" N., long. 88°56'00"
W.); 731-1,097 meters; bottom temperature 5.0° C. (at 1,097 meters); 1878 [Hartlaub,
1912; A. H. Clark, 1918].

Albatross station 2353; between Yucatan and Cuba (lat. 20°59'00" N., long.
86°23'00" W.); 305 meters; bottom temperature 17.1° C.; coral; January 22, 1885 (2).

Blake station 45; northwest of the Dry Tortugas, Florida (lat. 25°53'00" N., long.
84°21'00" W.); 185 meters; bottom temperature 16.53° C.; 1878 [Pourtales, 1878; Bell,
1882; P. H. Carpenter, 1881, 1883, 1888; Hartlaub, 1912; A. H. Clark, 1907, 1908, 1918,
1923] (1, M. C. Z., 267).

Atlantis station 3303; Cuba; off Playa Baracoa, Habana Province (lat. 23°05' N.,
long. 82°33' W.) ; 475 meters; March 23, 1939 [H. L. Clark, 1941].

Albatross station 2153; Cuba; off Habana (lat. 23°10'19" N., long. 82°23'10" W.);
517 meters; bottom temperature 13.2° C.; coral; April 30, 1884 (1).

Albatross station 2154; Cuba; off Habana (lat. 23°10'16" N., long. 82°22'54"
W.); 567 meters; bottom temperature 15.33° C.; coral bottom; April 30, 1884 [A. H.
Clark, 1909, 1918, 1921; Gisleii, 1934] (4, U.S.N.M., 25472 [type of margaritacea], 25475
[type of inornata, Plate 32, Figure 98], 36078, 34644).

Albatross station 2155; Cuba; off Habana (lat. 23°10'21" N., long. 82°22'44"
W.); 548 meters; coral bottom; April 30, 1884 (1, U.S.N.M., 34818).

Albatross station 2 156; Cuba; off Habana (lat. 23°10'35" N., long. 82°21'55" W.);
508 meters; bottom temperature 15.44° C.; coral bottom; April 30, 1884 (1, U.S.N.M.,
16898).

Albatross station 2166; Cuba; off Habana (lat. 23°10'36" N., long. 82°20'30" W.) ;
358 meters; bottom temperature 22.2° C.; coral bottom; May 1, 1884 (1).

Albatross station 2161; Cuba; off Habana (lat. 23°10'36" N., long. 82°20'28"
W.); 267 meters; coral bottom; April 30, 1884 (1, U.S.N.M., 34947).

Albatross station 2337; Cuba; off Habana (lat. 23°10'39" N., long. 82°20'21"
W.); 364 meters; coral bottom; January 19, 1885 (1, U.S.N.M., 34559).

Albatross station 2342; Cuba; off Habana (lat. 23°10'39" N., long. 82°20'21"
W.); 367 meters; coral bottom; January 19, 1885 [A. H. Clark, 1909, 1918, 1921;
Hartlaub, 1912; Clarke and Wheeler, 1917, 1922; Gislen, 1934] (7 + , U.S.N.M., 25476
[type of concinna], 34553, 36246).

Albatross station 2347; Cuba; off Habana (lat, 23°10'39" N., long. 82°20'21"
W.); 395 meters; coral bottom; January 20, 1885 (fragments, U.S.N.M., 34606).

Albatross station 2159; Cuba; off Habana (lat, 23°10'39" N., long. 82°20'08"
W.); 179 meters; coral bottom; April 30, 1884 (3).

Albatross station 2319; Cuba; off Habana (lat. 23°10'37" N., long. 82°20'06"
W.); 261 meters; gray coral; January 17, 1885 (r, U.S.N.M., 34594).

Corw-in station 2 ; 1.6 miles off La Chorrera, near Habana, Cuba; 494 meters; May
24, 1867 [Pourtales, 1868, 1869; P. H. Carpenter, 1879, 1883, 1888; Hartlaub, 1895,

340 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

1912; Minckert, 1905; A. H. Clark, 1907, 1909, 1918, 1923] (2 + , U.S.N.M., 36135;
M. C. Z., 267).

Blake station 101; Cuba; off Morro Light, Habana; 320-457 meters; December
1878 [Hartlaub, 1912; A. H. Clark, 1918].

University of Iowa's Bahama Expedition station 2; Cuba; about 2.5 miles off
Habana; 201 meters [H. L. Clark, 1918] (1, U.S.N.M., E. 4340).

Albatross station 2152; Cuba; 2.5 miles northwest of Habana Light; 707 meters;
bottom temperature 10.55° C.; April 30, 1884 (1).

University of Iowa's Bahama Expedition station 9; Cuba; off Habana; 366
meters [H. L. Clark, 1918] (fragments, M. C. Z., 736, 746).

University of Iowa's Bahama Expedition station 16; Cuba; off Habana; 366
meters [H. L. Clark, 1918].

Albatross stations 2319-2350; from Habana, Cuba, to Yucatan; 60-510 meters;
January 17-20, 1885 [A. H. Clark, 1909, 1918; Gislen, 1934; H. L. Clark, 1941] (8,
U.S.N.M., 25473 [type of pulchra], 34558, 34887, 34888).

Albatross station 2330; Cuba; off Habana (lat. 23°10'48" N., long. 82°19'15"
W.); 221 meters; fine gray coral; January 17, 1885 [A. H. Clark, 1909] (1, U.S.N.M.,
25474 [type of gemmata]).

Albatross station 2333; Cuba; off Habana (lat. 23°10'36" N., long. 82°19'12"
W.); 309 meters; fine white coral; January 19, 1885 (1, U.S.N.M., 34554).

Albatross station 2320; Cuba; off Habana (lat. 23°10'39" N., long. 82°18'48"
W.); 237 meters; fine coral; January 17, 1885 (2, U.S.N.M., 34556, 34557).

Albatross station 2334; Cuba; off Habana (lat. 23°10'42" N., long. 82°18'24"
W.); 122 meters; white coral; January 19, 1885 (1).

Albatross station 2327; Cuba; off Habana (lat. 23°11'45" N., long. 82°17'54" W.);
333 meters; fine brown sand; January 17, 1885 (1, U.S.N.M., 34555).

Atlantis station 2999; Cuba; Bahia de Matanzas (lat. 23°10' N., long. 81°29' W.) ;
265^20 meters; March 17, 1938 [H. L. Clark, 1941].

Atlantis station 3000; Cuba; Bahia de Matanzas (lat. 23°10' N., long. 81°29' W.);
311-466 meters; March 21, 1938 [H. L. Clark, 1941].

Atlantis station 3466; Cuba; Bahia de Matanzas (lat. 23°09' N., long. 81°27'30"
W.); 366 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3478; Cuba; Bahia de Matanzas (lat. 23°09' N., long. 81°27'30"
W.);439 meters; May 11, 1939 [H. L. Clark, 1941].

Atlantis station 3482; Cuba; Bahia de Matanzas (lat. 23°09' N., long. 81°27'30"
W.); 347 meters; May 11, 1939 [H. L. Clark, 1941].

Atlantis station 3465; Cuba; Bahia de Matanzas (lat. 23°09' N., long. 81°27' W.);
320 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3467; Cuba; Bahia de Matanzas (lat. 23°11'30" N., long. 81°26'
W.); 393 meters; May 9, 1939 [H. L. Clark, 1941].

Atlantis station 3326; Cuba; Bahia de Cochinos (lat. 22°09' N., long. 81°09' W.);
484 meters; April 4, 1939 [H. L. Clark, 1941].

Atlantis station 2987; Cuba; north of Puerto Sagua la Grande (lat. 23°22' N.,
long. 79°53' W.); 512-548 meters; March 13, 1938 [H. L. Clark, 1941].

Atlantis station 3438; Cuba; north of Caibarien (lat. 23°05'30" N., long. 79°37'
W.); 484 meters; May 2, 1939 [H. L. Clark, 1941].

A MONOGRAPH OF THE EXISTING CRINOIDS 341

Atlantis station 3434; Cuba; north of Caibarien (lat. 23°10' N., long. 79°35' W.);
475 meters; May 1, 1939 [H. L. Clark, 1941].

Atlantis station 3430; Cuba; north of Caibarien (lat. 22°59' N., long. 79°29' W.);
430 meters; May 1, 1939 [H. L. Clark, 1941].

Atlantis station 3431; Cuba; north of Caibarien (lat. 23°02' N., long. 79°29' W.);
448 meters; May 1, 1939 [H. L. Clark, 1941].

Atlantis station 3432; Cuba; north of Caibarien (lat. 23°05' N., long. 79°29' W.);
457 meters; May 1, 1939 [H. L. Clark, 1941].

Atlantis station 3436; Cuba; north of Caibarien (lat. 23°05' N., long. 79°28' W.);
466 meters; May 2, 1939 [H. L. Clark, 1941].

Atlantis station 3435; Cuba; north of Caibarien (lat. 23°05' N., long. 79°25' W.);
466 meters; May 2, 1939 [H. L. Clark, 1941].

Atlantis station 2984; Cuba; north of Caibarien (lat. 23°16' N., long. 79°10' W.);
439-457 meters; March 12, 1938 [H. L. Clark, 1941].

Atlantis station 3425; Cuba; north of Caibarien (lat. 22°53'30" N., long. 79°10'
W.); 457 meters; April 30, 1939 [H. L. Clark, 1941].

Atlantis station 2983; Cuba; north of Caibarien (lat. 23°11' N., long. 79°08' W.);
430-475 meters; March 12, 1938 [H. L. Clark, 1941].

Atlantis station 2983A; Cuba; north of Caibarien (lat. 23°11' N., long. 79°08' W.);
430 meters; March 12, 1938 [H. L. Clark, 1941].

Atlantis station 2982A; Cuba; north of Punta Alegre (lat. 22°48' N., long. 78°50'
30" W.); 384 meters; March 11, 1938 [H. L. Clark, 1941].

Atlantis station 2982B; Cuba; north of Punta Alegre (lat. 22°47' N., long. 47°48'
30" W.); 375^20 meters; March 11, 1938 [H. L. Clark, 1941].

Atlantis station 2980B; Cuba; north of Punta Alegre (lat. 22°48' N., long. 78°48'
W.); 402-411 meters; March 10, 1938 [H. L. Clark, 1941].

Atlantis station 2982C; Cuba; north of Punta Alegre (lat. 22°46' N., long. 78°45'
W.); 356-411 meters; March 11, 1938 [H. L. Clark, 1941].

Atlantis station 2980A; Cuba; north of Punta Alegre (lat. 22°48' N., long. 78°41'
W.); 402-475 meters; March 10, 1938 [H. L. Clark, 1941].

Atlantis station 2980; Cuba; north of Punta Alegre (lat. 22°47' N., long. 78°40'
W.); 457 meters; March 10, 1938 [H. L. Clark, 1941].

Atlantis station 3388; Cuba; off Cayo Coco (lat. 22°32'30" N., ng. 78°09' W.) ;
466 meters; April 26, 1939 [H. L. Clark, 1941].

Atlantis station 3372; Cuba; off Puerto Tanamo (lat. 20°45' N., long. 75°17' W.);
548 meters; April 20, 1939 [H. L. Clark, 1941].

Caroline station 43; southeast of Moua Island, between Haiti a.n^ Puerto Rico
(lat. 18°03'45" N., long. 67°48'10" W.); 439-548 meters; February 11, 1933 (3,
U.S.N.M., E.5255, E.5261, E.5262).

Off St. Thomas, Virgin Islands; 439 meters; Capt. A. Morrell, 1913 [A. H. Clark,
1929] (I.B.M.).

Caroline station 100; north of St. Thomas (lat% 18°40'15" N., long. 64°50'15" W.);
274 meters; March 4, 1933 (1, U.S.N.M., E.5235).

Caroline station 102; Virgin Islands (lat. 18°51' N., long. 64°33' W.); 256 meters;
March 4, 1933 (1, U.S.N.M., E.5256).

342 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

One-and-one-half miles west of Frederiksted, St. Croix; about 475 meters; Dr. Th.
Mortensen, January 18, 1906 (1, C. M.).

Blake station 157; off Montserrat; 219 meters; January 1879 [Hartlaub, 1912; A. H.
Clark, 1918] (3 + , M. C. Z., 272, 322).

Blake station 158; off Montserrat; 271 meters; stony bottom; January 1879 [Hart-
laub, 1912; A. H. Clark, 1918].

Blake station 193; off Martinique (lat. 14°43'48" N., long. 61°11'25" W.); 309
meters; bottom temperature 10.56° C.; sand, shells, and dark mud; February 5, 1879
[Hartlaub, 1912; A. H. Clark, 1918].

Blake station 198; off Martinique (lat. 14°30'40" N., long. 61°06'50" W.); 250
meters; bottom temperature 11.39° C. ; rocky bottom; February 6, 1879 [Hartlaub,
1912; A. H.Clark, 1918].

Investigator; Capt. A. Cole; apparently off Martinique [Hartlaub, 1912].

Blake station 219; off St. Lucia (lat. 13°49'50" N., long. 61°03'50" W.); 276
meters; bottom temperature 13.89°C.; gray sand; February 15, 1879 [Hartlaub, 1912;
A. H. Clark, 1918] (1, M. C. Z., 271).

Albatross station 2752; between St. Lucia and St. Vincent (lat. 13°34'00" N.,
long. 61°04'00" W.); 514 meters; bottom temperature 8.89° C.; broken shells; Decem-
ber 4, 1887 (1, U.S.N.M., 21704).

Albatross station 2753; between St. Lucia and St. Vincent (lat. 13°34'00" N., long.
61°03'00" W.); 514 meters; bottom temperature 8.89° C.; black sand; December 4,
1887 [A. H. Clark, 1909, 1918, 1921, 1923; Gislen, 1934; H. L. Clark, 1941] (11, U.S.
N.M., 25477 [type of insculpta], 21705, 21707, 21709, 36144; M. C. Z., 358).

Blake station 283; off Barbados (lat. 13°05'05" N., long. 59°40'50" W.); 431
meters; bottom temperature 9.44° C.; hard bottom; March 7, 1879 (1, M. C. Z., 50).

Blake station 269; off St. Vincent (lat. 13°07'55" N., long. 61°05'36" W.); 227
meters; bottom temperature 14.17° C.; coral; March 3, 1879 [Hartlaub, 1912; A. H.
Clark, 1918].

Blake station 232; off St. Vincent (lat. 13°06'45" N., long. 61°06'55" W.); 159
meters; bottom temperature 16.67° C.; coral; February 21, 1879 [Hartlaub, 1912].

Blake station 272; off Barbados (lat. 13°04'12" N., long. 59°36'45" W.); 139
meters; bottom temperature 18.20° C.; coral and broken shells; March 5, 1879 [Hart-
laub, 1912].

Blake station 241; off the Grenadines (lat. 12°28'22" N., long. 61°32'18" W.); 298
meters; bottom temperature 11.67° C.; sand and coral; February 24, 1879 [von Graff,
1883, 1884; P. H. Carpenter, 1888; Braun, 1888; A. H. Clark, 1907, 1918; Hartlaub,
1912].

Blake station 259; off Grenada (lat. 12°03'15" N., long. 61°46'25" W.) ; 291 meters;
sand and ooze; bottom temperature 11.95° C.; February 28, 1879 [Hartlaub, 1912].

Blake station 249; off Grenada (lat. 11°48'15" N., long. 61°48'45" W.); 479
meters; bottom temperature 8.33° C.; coarse sand; February 27, 1879 [Hartlaub, 1912;
A. H. Clark, 1918].

Caribbean Islands; 227-479 meters [P. H. Carpenter, 1888].

No locality; Blake [Hartlaub, 1912; A. H. Clark, 1918].

St. Helena; 2 miles S. 49° E. from Long Eange Point; 280-360 meters; hard
bottom; Dana, February 24, 1930 [Gislen, 1933].

A MONOGRAPH OF THE EXISTING CRINOIDS 343

St. Helena; 2 miles off Bay Point; 480 meters; Dana, February 24, 1930 [Gisl^n,
1933].

Geographical range. — From the Yucatan Bank, the Florida Keys, northern Cuba,
and the southern Bahamas eastward and southward along the Antillean chain to Bar-
bados and Grenada; also St. Helena.

Bathy metrical range. — From 139 to 707 meters.

Thermal range.— From 8.33° to 18.20° C.

History. — In a paper dated December 26, 1867, but distributed early in 1868,
Count Louis Franc. ois de Pourtales described Comatula brevipinna as follows:

Ten arms. Mouth and anus not seen in the only specimen examined. About 15 cirrhi, with
the same number of long articulations. Seven or eight articulations to every syzygium. The two
radials are visible, and have, as well as the axial radials and the two first brachials, a smooth tubercle
in the middle. The same pieces are denticulated on the sides, the denticulations meeting those of
the collateral radials and brachials, so as to close up the angle between them. A row of very small
tubercles on the proximal border of the radials and radial axials. The articulations of the arms
somewhat imbricate. First pinnule longest with about twelve joints. The other pinnules very
short, having only five or six joints in the middle of the arm, but lengthening out again near the end
of the arm, the last ones being tipped with a hook, like the cirrhi.

In the only specimen obtained one of the arms is abortive and divided into three very short
branches; to compensate, one of the arms of the next pair is divided into two from its origin.

In 270 fathoms off Havana (Corwin station 2].

In another paper published in November 1869 Count Pourtales said that Antedon
brevipinna Pourt. [Comatula brevipinna Pourt.] was not obtained again since the first
specimen was dredged in 1867.

In a paper published on December 14, 1878, Pourtales described Antedon granulifera
in the following terms:

Twenty arms. Centrodorsal piece hemispherical and covered with cirrhi in the young, but
becoming bare and flattened in the middle at a later period, showing more or less obsolete traces of
the sockets. At the junction with the radials it has five knobs projecting into the interambulacral
spaces. Cirrhi in two or more rows, with fifteen to eighteen joints, longer than broad, except the
two or three first ones, which are very thick. Penultimate with a spine. First radials entirely
concealed, very firmly connected with one another and with the rosette. Second radials [IBri]
thin; axials very depressed, pentagonal. First brachials rather flattened and in close lateral contact.
Three brachials between primary and secondary axials, one between secondary and tertiary. Syzygia
rather irregular, nine, ten, or more joints apart. Sometimes there are syzygia in the first and second
joints of the arms. The joints are somewhat saddle-shaped, with a deep notch for the insertion of
the pinnules and a point on the proximal border fitting into a shallow notch of preceding joint. About
the middle of the arm they are frequently, but not always, ornamented with bead-like tubercles, of
which the middle one is largest. These tubercles are also found generally on the radials. First
pinnule longest and very broad on first brachial, thence diminishing in length toward extremity.
The joints of the pinnules are very broad. Mouth central. Spread 20 to 25 cin.

[Blake] Station 45. Lat. 25°33' N., Long. S4°21' W. 101 fathoms.

In his memoir on the genus Actinometra published in 1879 Dr. P. H. Carpenter
said that he was unable, on the basis of the published description, to assign Comatula
brevipinna either to Antedon or to Actinometra.

In a preliminary report upon the comatulids of the Blake expedition published on
October 1, 1881, Dr. Carpenter mentioned Actinometra granulifera as a species in
which there is a considerable amount of auambulacral plating in the anal area; he said

344 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

it is usually of the nature of an aggregation of tubercles rather than of a regular pave-
ment of plates.

Prof. F. Jeffrey Bell in 1882 published a specific formula for Antedon granulifera.
Early in 1883 this specific formula was emended by Dr. P. H. Carpenter, who pub-
lished one also for Antedon brevipinna.

In 1883 Prof. Ludwig von Graff described the myzostomes found on a specimen
on Antedon pourtalesii (nomen nudum) from Blake station 241, repeating this informa-
tion in 1884.

In his report upon the comatulids of the Challenger expedition, published in 1888
Dr. Carpenter listed Antedon brevipinna among the species with 10 arms and also among
the species with more than 10 arms and the IIBr series 2. He included it in a list of the
10-armed species in the Blake collection and remarked that, although normally IIBr
2 series are present, they are now and then absent in certain individuals. Antedon
brevipinna was included in his key to the species of the Spinifera group, and he gave the
range as Straits of Florida in 270 fathoms. This is Corwin station 2, at which only
PourtaleV single type specimen was dredged.

Carpenter included Antedon granulifera in his list of species with more than 10
arms with the IIBr series 4 (3 +4) and the IIIBr series 2(1 +2). He remarked that there
is a syzygy between the two elements of the IIIBr series in this species which escaped
the notice of Pourtales. He made Antedon granulifera the type of a special group, the
Granulifera group including " Tridistichate species with plated ambulacra and the lower
parts of the rays flattened laterally." He noted that neither the lateral flattening of
the rays, nor the plated disk and ambulacral skeleton of this species, seem to have
attracted the attention of Count Pourtales when he examined it, though they have
since turned out to be characters of primary systematic value, and called attention to
the fact that Pourtales had not noticed the syzygies between the two outer elements
of the IIBr series and between the two elements of the IIIBr series; but he said that in
neither case is the syzygy at all easy to recognize, and his omission to notice it is there-
fore not surprising. He said that in granulifera some of the IIBr series are usually
absent, so that the arms spring directly from IBr axillaries, and noted that in arms
arising from IBr axillaries the first syzygy is between brachials 3 + 4, while in other arms
brachials 1+2 are united by syzygy, and brachials 3+4 may or may not be united by
syzygy. He included Antedon granulifera in his key to the species of the Granulifera
group in which it was paired with Antedon distincta, the difference given being that in
granulifera the lower pinnules are "rather stout," whereas in distincta they are "com-
paratively slender." He said that some of the characters of Antedon angusticalyx
and A. inaegualis appear in A. granulifera of the Caribbean Sea. Later, under Antedon
distinc.ta, he said that this species differs from A. angusticalyx and A. inaegualis in the
long interval between the first and second syzygies in the arms, and also in the separa-
tion of the IIBr axillaries of adjacent rays by the pinnules on the preceding ossicles,
which are attached more toward the dorsal surface than usual. This is less marked in
A. granulifera, though it agrees with A. distincta in the long syzygial interval. On
the other hand, he said, the joints of the genital pinnules of A. distincta are more uni-
formly expanded than in A. granulifera, which rather resembles A. angusticalyx and
A. inaegualis in this respect. He noted that A. granulifera seems to be fairly abundant

A MONOGRAPH OF THE EXISTING CRINOIDS

345

in the Caribbean Sea, but it exhibits a good deal of variation in its characters, which,
he said, would be fully discussed in his report upon the Blake comatulids. He said
that Antedon (Koehlcr metro) porrecta and A. (Thalassometra) multispina may serve as
a connecting link between A. (Stiremetra) lusitanica and the Caribbean A. granulijera.
He gave the range of granulifera as Caribbean Islands, in 101-120 fathoms.

In the Challenger report there appears the name Antedon pourtalesi. This is an
emendation of the name Antedon pourtalesii used as a nomen nudum by von Graff in
1883 and 1884 and by Braun (following von Graff) in 1888. The names used by von
Graff were given him by Carpenter. After supplying von Graff with the name Anti dun
pourtalesii Carpenter was informed by Prof. F. Jeffrey Bell, who was a classical scholar,
that this and similar names should end in a single "i" instead of in two, and so in the
Challenger report he used the spelling pourtalesi. Carpenter included Antedon pour-
talesi in his list of species with more than 10 arms and the IIBr and IIIBr series of 2
elements. He said that it always has one and sometimes two axillaries beyond the
IBr axillary, but the IIBr series are not always followed by IIIBr series. Antedon
pourtalesi, he said, is a fine species which he had dedicated to the memory of the late
Count Pourtales, adding that it is the host of Myzostomum brevipes von Graff (see
pt. 2, p. 661). He included pourtalesi in his key to the species of the Spinijera group
of Antedon, in which it is paired with brevipinna; pourtalesi Carpenter, MS. is said to
have "The pinnules from the tenth to twentieth brachials have the third to fifth joints
flattened and expanded laterally," while in brevipinna "The genital pinnules are com-
paratively slender with very slightly expanded joints." He listed Antedon pourtalesi
among the species found between 100 and 200, and also between 200 and 350 fathoms,
and gave the range as the Caribbean Islands, in 124-262 fathoms.

Dr. Clemens Hartlaub in 1895 listed Antedon brevipinna as a species of the Basicurva
group occurring hi water up to 500 fathoms in depth, giving the range as Straits of Florida
in 270 fathoms.

Dr. Wilhelm Minckert in 1905 gave an account of the distribution of the syzygies
and regeneration in Antedon brevipinna based upon material in the Blake collection.

In my first revision of the old genus Antedon published in 1907 brevipinna, granulif-
era, and pourtalesi were assigned to the new genus Cliaritometra, and in 1908 Charitometra
brevipinna was compared with a new species, Ch. smithi. In another paper published
in 1908 I described and figured a specimen with three pinnules on the same side of an
arm on three consecutive brachials that I identified as Charitometra imbricata (= Antedon
granulifera P. H. Carpenter 1888, not Antedon granulifera Pourtales l878 = Comatula
brevipinna Pourtales 1869 = Antedon pourtalesi P. H. Carpenter 1888). I assumed that
because Carpenter did not mention the granular ornamentation in his key to the species
of the Granulifera group the specimen he regarded as representing granulifera was with-
out it, and therefore not the granulifera of Pourtales. But, as noted by Pourtales him-
self, these tubercles are not always present in the specimens of the type series, and are
therefore wholly without systematic significance. In a revision of the family Thalas-
sometridae published on January 9, 1909, I established the new genus Crinometra and
listed as the included species Pachylometra brevipinna (Pourtales) and Pachylometra
imbricata (A. H. Clark). In a paper published on June 19, 1909, I described briefly

843803—50

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346 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Crinometra pulchra, C. margaritacea, C. concinna, C. insculpta, and C. gemmata. In a
paper published on November 16, 1909, I wrote:

Carpenter was loth to believe that a single species could be both "bi-" and "tri-distichate" ; he
observed the more or less frequent occurrence of both forms in the same individual, but he assigned the
specimens to their systematic position on the strength of the character of the majority of their series.
This is usually a safe enough guide, but in a few cases, such as this [Comanthus parvicirra ("rotalaria")],
it is unreliable, and leads to erroneous conclusions. Minckert, on the other hand, had gone too far
in the opposite direction ; he credits a certain Caribbean species of Charitometrinae, Crinometra brevipin-
na, with the possession of IIBr series which may be all 4(3 + 4), all 2, or both in any combination, and
he even makes it the type of a new "group", the "Brevipinna group". In reality he has confused a
number of perfectly distinct species some of which have one arrangement, some the other, none,
however, having both in equal proportions. Crinometra in this respect is exactly like Pachylometra [in
the broad sense], its representative in the East Indies.

The extensive collections brought together by the United States Coast Survey
steamers, particularly the Blake, together with a few from other sources, as for instance
those that had been taken by Capt. A. Cole of the cable repair ships Enterprise and
Investigator, had been sent by Alexander Agassiz to Dr. P. H. Carpenter for study and
report. Some time after Dr. Carpenter's death on October 21, 1891, they were reas-
signed to Dr. Clemens Hartlaub. One of Hartlaub's students, Dr. Wilhelm Minckert,
used the material in connection with a paper published in 1905, but the complete report
was not published by Hartlaub until 1912.

Dr. Hartlaub was a friend and admirer of Dr. Carpenter, and his work on the Blake
comatulids was modeled after the Challenger report. He told me that he considered it
his duty to do this as the work had originally been undertaken by Carpenter, and also
he wished to make his report conformable to the treatment in the Challenger report.

His account of this species is most excellent and exhaustive. He could not quite
bring himself to adopt Minckert's concept of a Brevipinna group including species in
which the IIBr series may be either 4(3+4) or 2, or both in any combination, but re-
verted to Carpenter's classification in which those species with plated ambulacra
sharply flattened sides, and all or a majority of the IIBr series 4(3+4) were assigned to
the Granulifera group and those, otherwise similar but with the IIBr series 2, were
assigned to the Spinijera group.

He was thus led to distribute his specimens among three species, angusticalyx and
granulifera in the Granulifera group, and brevipinna in the Spinijera group; but he dis-
cussed some specimens that seemed to him to be intermediate between granulifera and
brevipinna, although he could not bring himself to admit the specific identity of the two
forms. In identifying certain specimens with the Indo-Pacific angusticalyx, a species
known to him only by Carpenter's description and figures, he was undoubtedly influenced
by Carpenter's extensive comparisons between angusticalyx and granulifera in the Chal-
lenger report.

He divided brevipinna into twelve varieties. Of the twelve new names proposed by
him seven (gracilis, pulchra, elegans, tuberosa, diadema, laevis, and spinosa) had previous-
ly been used in the genus Antedon. But since, priority in nomenclautre is not concerned
with names of a lower category than subspecies, his varietal names are used herein with
the exception of pulchra, which conflicts with Crinometra pulchra, 1909, representing a
different variety.

A MONOGRAPH OF THE EXISTING CRINOIDS 347

Hartlaub's determinations with the equivalents adopted herein are as follows:

Granulifera group:

Antedon (mgusticalyx=Crinotnetra brevipinna var. angusla, nov.

Antedon granulifera = C. b. var. granulifera, and C. b. var. geminata
Spinifera group:

Antedon brevipinna=C. b. var. brevipinna

Antedon brevipinna var. decora=C. b. var. insculpla

Antedon brevipinna var. gracilis=C. b. var. gracilis

Antedon brevipinna var. pulchra=C. b. var. pulchella, nov.

Antedon brevipinna var. elegans = C. b. var. concinna

Antedon brevipinna var. tuberosa=C. b. var. tuberosa

Antedon brevipinna var. diadema — C. b. var. diadema

Antedon brevipinna var. pourtalesi=C. b. var. pourtalesi

Antedon brevipinna var. laevis = C. b. var. faenis

Antedon brevipinna var. spinosa=C. b. var. spinosa

Antedon brevipinna var. coronala=C. b. var. coronata

Antedon brevipinna var. orna(a = C. 6. var. ornata

Antedon brevipinna var. granulosa = C. b. var. granulosa

In 1914 Prof. Frank Wigglesworth Clarke and Dr. W. C. Wheeler published an
analysis of the inorganic components of the skeleton of this species (see pt. 2, p. 299,
Crinometra concinna). This information was republished in 1917 and 1922.

In his report upon the Crinoidea collected by the Bahama Expedition from the
University of Iowa in 1893 Dr. Hubert Lyman Clark in April, 1918, recorded and gave
notes on Crinometra gracilis from station 2, and C. ornata from stations 9 and 16.

In my report upon the unstalked crinoids of the Siboga expedition published in
1918 I listed all the forms referable to Crinometra under then- original names, and said
that the species referred to by Hartlaub as Antedon angusticalyx P. H. Carpenter,
A. granulifera Pourtales, and A. pourtalesi P. H. Carpenter, as well as A. brevipinna
(Pom-tales) belong in Crinometra. In my report upon the Crinoidea of the Danish
Ingolf Expedition I listed, as members of the genus Crinometra, C. brevipinna, C.
insculpta, C. granuli/era, and C. gemmata and gave their ranges. In 1929 I recorded,
without comment, a specimen of Crinometra brevipinna from off St. Thomas, V. I., in
240 fathoms that had been presented to the British Museum by Capt. A. Morrell.

In 1933 Prof. Torsten Gislen described and figured an interesting new form from St.
Helena which he called Crinometra transversa, and in 1934 he discussed the brachial
structure of Crinometra concinna, C. gemmata, C. imbricata, C. insculpta, C. margaritacea,
C. pulchra, and C. transversa.

Dr. Hubert Lyman Clark in 1941 recorded Crinometra granulifera, C. insculpta,
and C. pulchra from various localities about Cuba where they had been dredged by the
oceanographic ship Atlantis, working under the joint auspices of the University of
Havana and Harvard University.

Genus CHARITOMETRA A. H. Clark

Antedon (part) VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, p. 17, and following
authors.

Charitometra A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (diagnosis; genotype
Antedon incisa P. H. Carpenter, 1888); Bull. Mus. Coinp. Zool., vol. 51, No. 8, 1908, p. 245
(same); Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136 (referred to the Thalassometridae) ;

348 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Proc. U. S. Nat. Mus., vol. 34, 1908, p. 211 (referred to the Thalassometridae) , p. 212 (occurs
in the West Indies, Japan, and the Hawaiian Islands) , p. 275 (proximal ornamentation) ; vol.
35, 1908, p. 120 (arm structure), fig. 19, p. 120; Amer. Nat., vol. 42, No. 500, 1908, p. 542 (ex-
cluding the aculeata, hepburniana, basicurva, and tuberosa groups, a characteristic oceanic genus);
No. 503, p. 723 (range; habitat); Geogr. Journ., vol. 32, No. 6, 1908, p. 603 (oceanic, excluding
the aculeata, hepburniana, basicurva, and tuberosa groups); Proc. Biol. Soc. Washington, vol. 22,
1909, p. 1 (revision), p. 20 (list of included species as restricted). — HARTLAUB, Mem. Mus.
Comp. Zool, vol. 27, No. 4, 1912, p. 286 (constitution; discussion). — A. H. CLARK, Crinoids of
the Indian Ocean, 1912, p. 9 (absent from Australia), p. 10 (absent from Japan), p. 11 (absent
from the west coast of the Malay Peninsula, the Andamans, and farther west), p. 25 (range),
p. 60 (in key), p. 226 (original reference; type); Unstalked crinoids of the Sibojo-Exped., 1918,
p. 172 (in key; range), p. 191 (key to the included species)/ — GISLEN, Nova Acta Reg. Soc. Sci.
Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 7 (relation to Diodontometra) ; Ark. Zool., vol. 19, No.
32, Feb. 20, 1928, p. 9; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 18;
Kungl. Svensk. Vet.-Akad. Handl., ser. 3, vol. 17, No. 2, Oct. 3, 1938, p. 20.

Diagnosis. — The genital pinnules have the third and fourth or fourth and fifth
segments greatly expanded, the abruptly narrower portion of the pinnules beyond
being shorter than the expanded portion; the basal portion of the animal is compressed,
the two sides in lateral view making an angle of about 45° with each other; the IBr
series and lower brachials are in close lateral contact and are sharply and broadly
flattened against their neighbors; the 10 arms are 90-100 mm. long.

Geographical range. — From Fiji to the Kermadec Islands.

Bathymetrical range. — One definite record, 1,152 meters.

Thermal range. — One record, 4.17° C.

History. — The genus Charitometra was established in 1907 to include all the species
of the old genus Antedon now regarded as falling within the family Charitometridae
except for two that were assigned to the genus Poecilometra. It also included two
species, compressa and orion, which in 1909 were removed to the new genus Parametra
and transferred to the family Thalassometridae.

In 1909 Charitometra was restricted to its present significance through the removal
of most of the included species to the new genera Glyptometra, Strotometra, Pachyl-
ometra, Chlorometra, and Crinometra.

KEY TO THE SPECIES IN THE GENUS CHARITOMETRA

a1. Brachials from the fourth onward with prominently thickened, everted, and beaded or tuber-
culated distal edges, this feature gradually dying away after the brachials become triangular;
arms about 100 mm. long (Kermadec Islands; 1,152 meters) basicurva (p. 348)

a2. Brachials with unmodified distal ends, the arms appearing quite smooth (Kermadec Islands
and Fiji; 1,152 meters) incisa (p. 352)

CHARITOMETRA BASICURVA (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 279, p. 260, 495, p. 367; pt. 2, pi. 3, figs. 990, 991, pi. 26, fig. 1160, pi. 27, fig.

1167.]

Antedon basicurva VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, pp. 17, 70, 73 (my-
zostomes; Challenger station 170; women nudum). — P. H. CARPENTER, Challenger Reports, Zoology,
vol. 11, pt. 32, 1884, p. 84; pi. 54, fig. 9; pi. 55, fig. 7.— VON GRAFF, Challenger Reports, Narrative,
vol. 1, pt. 1, 1885, p. 316 (myzostomes). — P. H. CARPENTER, Challenger Reports, Zoology, vol.
26, pt. 60, 1888, p. 120 (description; Challenger stations 170A, 7175), pi. 2, figs. 2, a-d, pi. 21,
fig. 3, pi. 22, figs. 3, 4, text fig. 2, A, B, p. 100, duplicated on p. 122.— BRAUN, Centralbl. Bak-
teriol. und Parasitenkunde, vol. 3, 1888, p. 210 (myzostomes; after von Graff). — P. H. CAR-
PENTER, Journ. Linn. Soc. (Zool.), vol. 24, 1891, p. 67 (compared with (A. [Sliremetra] lusitan-

A MONOGRAPH OF THE EXISTING CRINOIDS 349

tea). — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 131 (systematic and bathy-
metrical relationships.) — BATHER, in Lankester, A treatise on zoology, pt. 3, Echinoderma, 1900,
fig. ix, 2, p. 102. — HUTTON, Index faunae Novae Zealandiae, 1904, p. 290 (listed). — MINCKERT,
Arch. Naturg., Jahrg. 71, 1905, vol. 1, p. 169 (syzygies). — HAMANN, Bronn's Klassen und Ord-
nungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Crinoids of the
Indian Ocean, 1912, p. 33 (identify).

Charitometra basicurva A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed);
Geogr. Journ. vol. 32, No. 6, 1908, p. 603 (type of non-oceanic group) ; Proc. Biol. Soc. Wash-
ington, vol. 22, 1909, p. 20 (listed); Crinoids of the Indian Ocean, 1912, p. 33 (identity), p. 226
(synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 49 (published references
to specimens in the B. M.; Challenger station 170A); Unstalked crinoids of the Szfcoja-Exped.,
1918, p. 191 (in key; range). — GISL^N, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 9 (notes).

Diagnostic features. — The brachials from the fourth onward have prominently
thickened and everted, and beaded or tuberculated, distal edges, this feature grad-
ually dying away after the brachials become triangular; the 10 arms are about 100
mm. long.

Description. — The centrodorsal is hemispherical with a very rough dorsal pole
and small interradial processes. According to the figures given by Carpenter the
cirrus sockets are evenly distributed, in 10 irregular columns in the young and 15 in
the fully grown.

The cirri are about XX, 18-20; the segments are very stout, most of them longer
than broad. The distal ends of the earlier segments overlap slightly, those of the later
ones more strongly, especially on the dorsal side so as to produce a blunt spine on the
distal edge, which is rather sharp on the penultimate.

The radials and sometimes portions of the IBri are concealed. The IBrj are
short and bandlike, in close lateral contact; they have raised edges which are often
somewhat crenulate, and there is usually a slight tubercle on the distal border cor-
responding to one on the axillary. The IBr2 (axillaries) are short and pentagonal
with a wide, open angle and more or less crenulated edges. The dorsal surface is very
convex with the margin more or less flattened, and with sharply flattened wall-like
sides.

The 10 arms are about 100 mm. long and are composed of about 120 brachials.
The first brachials are short, nearly oblong, and are closely united interiorly. The
second brachials are more wedge-shaped. Both rise toward their apposed edges to
form a median elevation (synarthrial tubercle) like that between the elements of the
IBr series. The following brachials are short until about the twelfth, after which
they are longer and more triangular, gradually becoming wedge-shaped. The ter-
minal brachials are elongated and slightly compressed laterally. The first four bra-
chials are wall-sided with flattened margins like the axillaries. In the proximal portion
of the arms the distal edge of each bracbial stands up as a sharp crenulated ridge from
which the surface slopes backward. Farther out on the arms as the brachials become
longer this sudden rise disappears, and the brachials overlap in the ordinary way.

Syzygies occur between brachials 3+4 and again from between brachials 10+11
to between brachials 17 + 18; the distal intersyzygial. interval is from 2 to 17 (usually
4 to 8) muscular articulations.

PI is short with about 22 segments of which the 6 pr ^ximal are trihedral and much
flattened on the outer side with a marked dorsal keel v hich is lost in the smaller ter-

350 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

minal segments. Pa is similar but rather smaller. P2 has fewer segments, but the
third and fourth are relatively broader, and in the succeeding pinnules very much
broader with their outer faces greatly expanded toward the ventral side. This condi-
tion is most marked at about P6 and then gradually decreases, being traceable to Pi2
or Pi5. After this is lost the pinnules gradually diminish in stoutness, but do not
increase much in length.

The disk is 7 mm. in diameter and is much incised and completely plated, as are
also the arms both along the ambulacra and at their sides. The gonads are protected
by stout anambulacral plates. The ambulacra of the distal pinnules have well denned
side plates alternating with, but often partly concealing, the sacculi, which are abun-
dant and very large, especially on the genital pinnules.

The color in alcohol is dark gray-brown, of the young individuals yellowish brown.

Notes. — In the Challenger report on the stalked crinoids Carpenter noted that in
this species the irregular double row of transversely oblong plates bordering the am-
bulacra! grooves on the disk is barely distinguishable from the anambulacral plates,
and the whole set encroaches very much upon the peristome so that in a dry state it
is scarcely visible.

He said that the first pair of pinnules in this species are considerably different
from their successors. PI is rather larger than Pa, but the general characters are
identical. All the segments are quite short, but the first five or six are broad, carinate,
and trihedral, with their outer sides flattened somewhat as in Aglaometra valida and
allied species. Traces of this flattening are apparent on P2, but Pb and the following
pinnules have the third and fourth segments very broad and expanded, though the
fifth is smaller again and its successors very much so. These lower segments, which
are so broad and almost flat on their outer side, afford support and protection to the
gonads which are situated on their inner faces. The ventral surface of the gonads is
covered by a pavement of anambulacral plates often with large sacculi imbedded in
them here and there. But there are no side and covering plates as in the distal pin-
nules. Carpenter said that the expansion of the third and fourth pinnule segments is
best developed about the tenth or twelfth brachials, after which it gradually becomes
less and less marked and the later segments more and more elongated. But the third
and fourth segments are often distinctly broader and flatter than their successors as
far out as the thirtieth brachial, after which they assume a more elongate form.

Carpenter said that in one quite young specimen about one-third the size of a
fully grown individual there is comparatively little trace of the expansion of the third
and fourth segments even on the lower pinnules. The arms, too, are much smoother
than in the adult, the edges of the lower brachials being but slightly raised and showing
no trace of the crenulation which is so marked hi the more mature individuals. The
radials are just visible as narrow curved bands immediately above the centrodorsal
which are not smooth and continuous as usual but broken here and there by pits. In a
slightly older individual they are represented only by a row of irregular processes
between the centrodorsal and the IBr1; while in the mature form they are altogether
invisible, though traces of the processes appear after the removal of the IBrj.

In this species Carpenter noted that the upper surface of the centrodorsal is so much
larger than the base of the radial pentagon that the IBrt partly rest upon it and so
completely conceal the radials as in some forms of Antcdon bifida. The cirrus sockets

A MONOGRAPH OF THE EXISTING CRINOIDS 351

are peculiar in having a very large articular facet in the center from which radiating
processes extend all around to the margin of the socket. The dorsal surface of the
radial pentagon is marked by a well denned basal star the angles of which do not,
however, appear externally. The central funnel of the calyx is smaller than in Stire-
metra breuiradia, as the ventral ends of the muscle plates are less everted than in that
type. Carpenter said there is a further resemblance between this species and the
mature Stiremetra breuiradia in the presence, of transverse ridges and furrows at the
lower ends of the muscular fossae; but he said he had found two radials without them
in a calyx of basicurva.

At the British Museum I examined five specimens of this species from Challenger
station 170 A and remarked that it had been well figured by Carpenter. After examining
these same specimens Gislen noted that the cirri are stout with a longitudinal carination
and the opposing spine in the form of a transverse crest.

Locality. — Challenger station 170A; near the Kermadec Islands, north of New
Zealand (lat. 29°45' S., long. 178°11' W.); 1,152 meters; bottom temperature 4.17° C.;
volcanic mud; July 14, 1874 [von Graff, 1884, 1885; P. H. Carpenter, 1884, 1888, 1891;
Braun, 1888; Hartlaub, 1895; Bather, 1900; Hutton, 1904; Minckert, 1905; Hamann,
1907; A. H. Clark, 1907, 1908, 1909, 1912, 1913, 1918; Gislen, 1928] (5, B. M.).

Doubtful locality. — Challenger station 175; near Kandavu, Fiji (lat. 19°02' S.,
long. 177°10' E.); 2,468 meters; bottom temperature 3.33° C.; globigerina ooze;
August 12, 1874 [P. H. Carpenter, 1888]. Carpenter said that only two comatulids are
recorded in the station book as having been found at this locality, and as the depth
is considerable he had little doubt that they were the two small species Stiremetra
bremradia and S. acutiradia. The arms of the latter were all loose and Carpenter said
it is quite possible that the few arm fragments of Charitometra basicurva may have been
among them; but no calyx of this species was obtained.

History. — Antedon basicurva was first mentioned by Prof. Ludwig von Graff in his
account of the myzostomes of the Challenger expedition published in 1884. The name
was a nomen nudum. He gave the locality as Challenger station 170. In his report on
the stalked crinoids of the Challenger expedition published in the same year Dr. P. H.
Carpenter gave a short note on the plating of the disk in Antedon basicurva, for which
he gave a specific formula, and figured a portion of a distal pinnule showing the side and
covering plates as well as the disk. In the report on the comatulids of the Challenger
expedition published in 1888 Carpenter described Antedon basicurva in detail and figured
it. In the same year Braun listed it as the host of certain myzostomes, taking his
information from von Graff.

In 1891 Carpenter compared Antedon basicurva with Antedon (Stiremetra) lusitanica,
and in 1895 Dr. Clemens Hartlaub discussed its systematic and bathymetrical re-
lationships. Dr. F. A. Bather in 1900 published a figure of a portion of a distal pinnule
with the side and covering plates redrawn from the figure published by Carpenter in
1884. Captain Hutton listed Antedon basicurva as a New Zealand species in 1904,
Minckert discussed the syzygics in 1905, and Hamann listed it in 1907.

In my first revision of the old genus Antedon' published in 1907 basicurva was
transferred to the new genus Charitometra. Charitometra basicurva was mentioned as the
type of an oceanic group in 1908, and was listed in 1909. In my memoir on the crinoids
of the Indian Ocean published in 1912 Charitometra basicurva was listed and the

352 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

synonymy and range were given. In 1913 I noted that I had examined five of Car-
penter's original specimens from Challenger station 170A at the British Museum and
that it had been well figured by Carpenter. In my memoir on the unstalked crinoids
of the Siboga Expedition published in 1918 basicurva was included in the key to the
species of Charitometra and the synonymy and range given. Prof Torsten Gislen in 1928
published notes on the specimens which he had examined in the British Museum.

CHAKITOMETRA 1NCISA (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 278, p. 260, 494, p. 367; pt. 2, pi. 3, figs. 992, 993.]

Antedon incisa VON GRAFF, Challenger Report, Zoology, vol. 10, pt. 27, 1884, pp. 18, 31, 70 (my-
zostomes; Challenger stations 170, 174; nomen nudum); Narrative, vol. 1, pt. 1, 1885, p. 316
(myzostornes) ; Zoology, vol. 20, pt. 61, 1887, p. 2 (myzostomes; Challenger station 170). —
P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 124 (description; Challenger
stations 170A, 174, B, C, or D), pi. 2, figs. 1, a-d; pi. 21, (figs. 1, 2). — BRAUN, Centralbl. Bakteriol.
und Parasitenkunde, vol. 3, 1888, p. 185 (myzostomes; after von Graff). — HARTLAUB, Bull. Mus.
Comp. Zool., vol. 27, No. 4, 1895, p. 131 (systematic and bathymetrical relationships). — LANG,
A text book of comparative anatomy, vol. 2, 1896, p. 312, fig. 258. — BUTTON, Index faunae
Novae Zealandiae, 1904, p. 290 (listed).— A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 140
(comparison with A. [Strotometral] hepburniana). — HAMANN, Bronn's Klassen und Ordungen des
Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Crinoids of the Indian Ocean,
1912, p. 33 (identity).

Charitomelra incisa A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed); Proc.
Biol. Soc. Washington, vol. 22, 1909, p. 20 (listed); Crinoids of the Indian Ocean, 1912, p. 33
(identity), p. 227 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 49
(published reference to specimens in the B. M.; Challenger stations 170A, 174) ; Unstalked crinoids
of the Siboga-Exped., 1918, p. 191 (in key; range).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20,
1928, p. 9, No. 43 (notes).

Diagnostic features. — The lower brachials are smooth with unmodified distal ends;
the 10 (rarely 11) arms are about 90 mm. long. This is possibly only a smooth-armed
variety of Ch. basicurva.

Description. — The centrodorsal is hemispherical with a rough dorsal pole and small
interradial processes. According to the figures the cirrus sockets are arranged in a single
irregular marginal row.

The cirri are about XV, 15-18; the segments are rather stout, most of them longer
than broad, the longest according to the figure not quite twice as long as broad. In
the younger cirri the later segments overlap very slightly on the dorsal side so as to
produce faint spines ; this is lost in the older cirri except in the penultimate, which bears
a strong opposing spine.

The radials are short and bandlike with curved borders and are in apposition above
the interradial processes of the centrodorsal. The IBri are somewhat longer and are in
close lateral contact and rather convex in the center where they are but little incised for
then- junction with the IBr2 (axillary) which is also sharply convex, short, and pentag-
onal, with very open angles. The axillaries and first four or five brachials have the
marginal portions of their dorsal surface flattened vertically, with sharp edges and wall-
like sides.

The 10 arms are about 90 mm. long. The first brachials are almost oblong and very
convex in the center. The second are shorter and more wedge-shaped. The brachials
following are smooth and rather short until about the tenth, then longer and obliquely

A MONOGRAPH OF THE EXISTING CRINOIDS 353

quadrate, becoming blunter and more elongated toward the end of the arm, but without
any overlap.

The first syzygy is between brachials 3+4, the next frequently between brachials
11 + 12, though sometimes not until between brachials 19+20, and the distal intersyzy-
gial interval is from 2 to 10, generally from 5 to 7, muscular articulations.

P! is longish with about 30 short segments, of which the proximal are rather flattened
on the outer side with a sharp dorsal keel. Pa is similar but shorter. P2 is longer with
fewer but larger segments of which the fourth and fifth are broad and expanded toward
the ventral side. This expansion increases in the following pinnules, which have the third
and fourth segments largest. This is most marked about Pi2, but is traceable to the thir-
tieth brachial. The remaining pinnules diminish in stoutness without increasing much in
length.

The disk is 7 mm. in diameter, much incised and pretty completely plated as are
also the brachial ambulacra. The gonads are protected by stout anambulacral plates.
The ambulacra of the distal pinnules have well marked side plates, which are generally
notched for the sacculi. The sacculi are large and abundant, especially on the distal
pinnules.

The color in alcohol is brownish white or light yellowish brown.

Notes. — Supplementing the foregoing description Carpenter wrote that this species
is readily distinguished from Ch. basicurva by the smoothness of the arms and the ap-
pearance of the radials externally. Another point of difference is that the wall-sidedness
of the arm bases extends out to the fifth or even the sixth brachial which is not the case
in Ch. basicurva. On the other hand, the basal segments of PI and Pa in the type from
station 170A are less flattened and not so distinctly trihedral as is Ch. basicurva so that
the proximal pinnules are more like their successors than is the case in that species.
But Carpenter noted that in the two individuals from station 174 (B, C, or D) where
Ch. basicurva did not occur the lower segments of PI show a distinct tendency toward
the trihedral form characteristic of that type.

Carpenter said that the radials are completely visible in all the specimens of
incisa, though they are shortest in those which are most mature, barely reaching half
the length of the IBri, to which they are nearly equal in some of the younger individuals.
He remarked that this species has a relatively smaller centrodorsal than basicurva so
that the radial pentagon covers it completely, and no part of it is exposed when the
IBri are removed. The dorsal aspect of the radial pentagon is much the same in the
two types, except for the portion of the radial which appears externally in Ch. incisa.
But the lower ends of the muscular fossae in the latter are almost entirely without the
ridge and furrow markings which are generally present in Ch. basicurva. The articular
facet of the cirrus sockets is relatively smaller in incisa than in basicurca, and the
radiating processes around the edge of the socket are less distinct.

After examining Carpenter's specimens in the British Museum Gislen noted that
there are no dorsal spines on the cirri and that the opposing spine is a transverse, not
bisected, ridge. On one specimen he found a IIBr 4(3+4) series following which on one
arm the first syzygy was between brachials 1 + 2.

Localities. — Challenger station 170A; near the Kermadec Islands, north of New
Zealand (lat. 29°45' S., long. 178°11' W.); 1,152 meters; bottom temperature 4.17° C.:
volcanic mud; July 14, 1874 [von Graff, 1884, 1885, 1887; P. H. Carpenter, 1888;

354 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Braun, 1888; Hartlaub, 1895; Lang, 1896; Huttou, 1904; A. H. Clark, 1907, 1909,
1912, 1913, 1918; Hamann, 1907; Gislen, 1928] (1, M. C. Z., 269).

Challenger station 174 (B, C, or D); near Kandavu, Fiji (lat. [about] 19°06' S., long,
[about] 178°18' E.); 466, 1,115, or 384 meters; bottom temperature (at 1,115 meters)
3.88° C.; coral mud; August 3, 1874 [von Graff, 1884, 1885; P. H. Carpenter, 1888;
Braun, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1909, 1912, 1913, 1918; Hamann,
1907; Gisleii, 1928J (3, B. M., labeled as from both stations).

Geographical range. — From the Kermadec Islands to Fiji.

Bathymetrical range. — One definite record, 1,152 meters.

Thermal range. — One definite record, 4.17° C.

History. — Antedon incisa was first mentioned as a nomen nudum by Prof. Ludwig
von Graff in his account of the myzostomes of the Challenger Expedition published in
1884; he gave as the localities stations 170 and 174. He mentioned it again in 1885
and also in 1887, when he gave the locality as station 170.

It was described in detail and figured by Dr. P. Herbert Carpenter in his report
on the comatulids of the Challenger Expedition published in 1888, and in the same year
it was listed as a host of myzostomes by Braun, quoting from von Graff. Dr. Clemens
Hartlaub in 1895 discussed its systematic and bathymetrical relationships, and in 1896
Prof. Arnold Lang reproduced Carpenter's figure (plate 21, figure 1) redrawn so as to
show all the arms and pinnules complete. In 1904 Capt. F. W. Hutton listed Antedon
incisa as a New Zealand species, and in 1907 it was listed by Hamann.

In my first revision of the old genus Antedon published in 1907 incisa was made
the type of the new genus Charitometra. In my revision of the families Thalassometri-
dae and Himerometridae published in 1909 I listed Charitometra incisa, and in my
memoir on the crinoids of the Indian Ocean published in 1912 it was again listed and
the synonymy and range were given. In my memoir on the unstalked crinoids of the
Siboga Expedition published in 1908 incisa was included in the key to the species of
Charitometra and the synonymy and range were given. In 1928 Prof. Torsten Gisl6n
published notes on the specimens in the British Museum.

Genus POECILOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Pop. Sci. Rev., vol. 4, No. 15, 1880, pi. 6, fig. 10, and following
authors.

Poecihmetra A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (diagnosis; genotype
Antedon acoela P. H. Carpenter, 1888) ; Bull. Mus. Comp. Zool., vol. 51, No. 8, 1908, p. 245 (same) ;
Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136 (referred to the Thalassometridae) ; Proc. U. S.
Nat. Mus., vol. 34, 1908, p. 211 (referred to the Thalassometridae), p. 212 (occurs in Japan);
Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (listed, with included species) ; Crinoids of the
Indian Ocean, 1912, p. 9 (absent from Australia), p. 11 (absent from the west coast of the Malay
Peninsula, from the Andamans, and from farther west), p. 25 (range), p. 60 (in key), p. 225
(original reference; type); Unstalked crinoids of the Siboga-'Exped., 1918, p. 172 (in key; range),
p. 190 (key to the included species).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 1928, p. 9;
Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 18.

Diagnosis. — The genital pinnules have the third to seventh and fifth to ninth seg-
ments greatly expanded, the segments beyond the expanded portion of the pinnules
being very small; the ossicles of the division series and lower brachials are relatively
narrow and well separated from each other, the gaps between them being more or less
completely bridged over by the lateral extension of the dorsolateral edge into a thin

A MONOGRAPH OF THE EXISTING CRINOIDS 355

flangelike border which persists as far as the fourth or fifth brachial; and the 10 arms
are 100-110 mm. long.

Geographical range. — From Celebes to southwestern Japan.

Bathymetrical range. — From 660 to 1,327 meters.

Thermal range.— From 5.44° to 5.95° C.

History. — The genus Poecilometra was established in 1907 to include Carpenter's
Antedon acoela, the type species, and another species that had been described a few
months earlier from southern Japan. The genus has since been maintained in its
original significance.

KEY TO THE SPECIES IN THE GENUS POECILOMETRA

a1. Centrodorsal large and broad, in large specimens about 5 mm. in diameter at the base; the profile
of the IBr series and arm bases makes only a very slight angle with the do rso ventral axis; the
IBr series are usually, though not always, somewhat constricted so that the arm bases broaden
rather suddenly above them; the cirri are XXV-XXX, 15-18; the arms are about 100 mm. long
(northern Celebes to Mindanao; 914-1,327 meters) acoela (p. 355)

a2. Centrodorsal smaller, 4 mm. in diameter at the base; the profile of the IBr series and arm bases
makes an angle of about 60°, or about 30° with the dorsoventral axis; there is no constriction of
the IBr series; the cirri are about XX, 20; the arms are 110 mm. long (southwestern Japan;
660 meters) scalaris (p. 359)

POECILOMETRA ACOELA (P. H. Carpenter)

[See vol. 1, pt. 1, figs. 7, 8, p. 63, 277, p. 260, 493, p. 367; pt. 2, pi. 3, figs. 988, 989, pi. 14, figs. 1057,
1058, 1061, pi. 26, fig. 1161, pi. 27, fig. 1169.]

Antedon sp. P. H. CARPENTER, Pop. Sci. Rev., vol. 4, No. 15, 1880, pi. 6, fig. 10 (side and covering
plates of a pinnule).

Anledon acoela P. H. CARPENTER, Challenger Reports, Zoology, vol. 11, part 32, 1884, pp. 57, 83,
84, 93, 109, 110, 113, 128, pi. 54, figs. 1-4; pi. 55, fig. 5; Quart. Journ. Micr. Sci., vol. 27, 1887,
p. 391 (sacculi), pi. 30, fig. 3 (side and covering plates); Challenger Reports, Zoology, vol. 26,
pt. 60, 1888, p. 132 (description; Challenger station 214), pi. 2, figs. 3, a-d; pi. 16, figs. 1-5. —
HARTLATJB, Nova Acta Acad. German., vol. 58, No. 1, 1891, p. 113 (in Gottingen Mus.). —
SHIPLEY AND MACBRIDE, Zoology, 1901, p. 269, fig. — MINCKERT, Arch. Naturg., Jahrg. 71, 1905,
vol. 1, Heft 1, p. 190 (syzygies and regeneration). — HAMANN, Bronn's Klassen und Ordnungen
des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed), pi. 12, fig. 1 (from Carpenter). — A. H.
CLARK, Crinoids of the Indian Ocean, 1912, p. 33 (identity).

Poecilometra acoela A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 362 (listed) ; Proc.
Biol. Soc. Washington, vol. 22, 1909, p. 18 (listed); Crinoids of the Indian Ocean, 1912, p. 33
(identity), p. 225 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 50
(published references to specimens in the B. M.; Challenger station 214; comparison with P. scalaris);
Unstalked crinoids of the Siboga-Exped., 1918, p. 190 (in key; range; references; notes; stations
122, 124), p. 273 (listed).— GISLEN, Zool. Bidrag Uppsala, vol. 9, 1924, p. 280.

Diagnostic features. — The lateral profiles of the IBr series are almost parallel,
those of the arm bases slightly diverging; the IBr series are constricted so that there
is a sudden broadening at the first brachial; in small individuals in which the constric-
tion of the IBr series has not developed the profiles of the proximal portion of the
animal diverges at an angle of about 45°; the Centrodorsal is large and broad, up to
5 mm. across at the base; the cirri are XXV-XXX, 15-18; and the arms are up to
100 mm. long.

Description. — The Centrodorsal is subconical or hemispherical. The cirrus sockets
are evenly distributed and are arranged roughly in 2 rows and from 10 to 15 columns.

356 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

The cirri are XXV-XXX, 15-18. Nearly all the segments are longer than broad,
according to the figure mostly about twice as long as broad. There is but little trace
of an opposing spine, and the terminal claw is curved and sharp.

The radials are visible only in young specimens. The IB^ are somewhat flattened
with a convex proximal and concave distal border. The IBr2 (axillaries) are more
convex, broadly pentagonal or almost rhombic, with a wide distal angle and sometimes
projecting deeply posteriorly into the IBrj. The dorsal surface of the elements of
the IBr series, the first two brachials, and the hypozygal of the first syzygial pair
project beyond their faces and sides, especially the latter which fall away rapidly from
the dorsal towards the ventral border.

The 10 arms are probably 100 mm. long and consist of about 100 brachials. The
first brachials are nearly oblong with rounded outer edges. The second are convex
and irregularly pentagonal. Those following are smooth and triangular, as long as
or longer than broad.

Syzygies occur between brachials 3+4, again at about brachials 12 + 13 or 13+14,
and distally at intervals of from 3 to 6 (usually 4 or 5) muscular articulations.

PI and Pft are composed of about 30 short segments the lowest of which is a good
deal wider than the others. In the pinnules from the fourth to the twenty-fifth brachial
about 3 to 5 of the segments are greatly expanded laterally to enclose the gonads, and
the first segment is much wider than its successors, especially in the lower pinnules.
The later pinnules have longer and more trihedral segments the lowest of which are
flatter.

The disk is 5 mm. in diameter, rather incised, and completely covered with irreg-
ular plates bearing short and blunt rodlike spines. The brachial ambulacra and the
interarticular spaces are well plated, and the expanded parts of the genital pinnules
are completely enclosed in an arched pavement of flat plates very regularly arranged
and devoid of ambulacra. The ambulacra of the later pinnules have very well
defined side plates, sometimes covering the sacculi and sometimes notched for them.
These are very abundant except on the non-tentaculiferous genital pinnules.

The color of young specimens in alcohol is straw color; the older ones are a dense
brownish gray, becoming a dark gray in the most mature.

Notes. — Carpenter said that in its general characters this species has many points
of resemblance with Charitometra basicurva, Ch. incisa, and Glyptometra tuberosa; but
the sides of the elements of the IBr series are not in close apposition and flattened
laterally against each other as in those types, for they fall away very rapidly from the
dorsal toward the ventral surface so that there is a considerable space between every
two postradial series, especially at the level of the articulation. This is smaller on the
surface than it is deeper down, for the lateral edges of the ossicle are produced out-
ward, like the projecting eaves of a roof. This condition is extremely marked in the
case of the IBrj, which has the proximal edge similarly produced so as to overlap the
minute portion of the radials which appears externally.

Carpenter said that the relative shapes of the elements of the IBr series vary ex-
tremely. In some individuals the IBri are approximately oblong and show hardly any
indication of an incised distal edge, while the axillaries are broadly pentagonal. On
the other hand, the axillaries sometimes project far back into the IBr: which then have
a deeply incised distal edge, while the proximal edge is also much curved.

A MONOGRAPH OF THE EXISTING CRINOIDS 357

In young specimens a considerable portion of the radials is visible, but the projec-
tion of the edge of the next following ossicle is almost as marked as in the mature
individual. In the youngest specimen with the arms about 40 mm. long the external
surface of the radials is rather less wide than that of the IBri and a trifle more than
half its length. It does not, however, increase in size with the corresponding parts of
the IBr series, but remains undeveloped and is sometimes marked by small tubercular
elevations like those on the centrodorsal from which it is with difficulty distinguish-
able. These are situated in the gap between the ventral edge of the centrodorsal and
the proximal edges of the IBri which project backward so as to overlap them.

Carpenter said that the most striking feature of acoela, and the one which allies
it most closely to the Basicurva group, is the great size both of the segments and of the
protecting plates of the genital pinnules. Even the pinnules of the second pair (P2
and Pb) are enlarged for the reception of the gonads, three of their middle segments
being expanded; and a little farther from the disk the fifth and the four or five follow-
ing segments are flattened and produced laterally, the proximal segment being often
much enlarged at the same time. This expansion is not almost entirely limited to
the outer side only as in Charitometra incisa, but it is equal on both sides of the medio-
dorsal line, and the ventral portion of these expanded segments is covered by an arched
pavement of strong plates, few in number but of large size and often very regularly
arranged. These protecting plates are much larger and better developed than in
either Charitometra incisa or Glyptometra tuberosa, and they often alternate more or
less regularly on opposite sides of the medioventral line of the pinnule, where there is
an opening in one of them for the exit of the genital products.

In the young individuals obtained, even in those with an arm length of 60 mm.,
there is no trace of the enlargement either of the pinnule segments or of the protecting
plates, although both are visible in the older form which still shows a considerable
part of the radials externally. In the regenerated arm, too, the lower pinnules are for
some time quite small and inconspicuous and altogether different from those of the
uninjured mature individual. This is the case even when the arm has attained almost
its full size and is absolutely larger than those of other individuals not yet quite mature,
but with comparatively large genital glands.

All these greatly enlarged genital pinnules are devoid of ambulacra, like the non-
tentaculiferous posterior arms of the Comasteridae; but at about the position of the
twenty-fifth brachial there is a sudden diminution in size both of the pinnule segments
and of the protecting plates, more especially of the latter. They become much smaller
and relatively more numerous, while the sacculi, which are absent from the large lower
pinnules begin to appear, just as they show themselves in the genital pinnules of
Glyptometra angusticalyx from the same station, while eventually the ambulacral skele-
ton shows itself above the small protecting plates, as in Glyptometra incerta. A little
farther out on the arms these protecting plates disappear, and the ambulacral skeleton
comes to rest directly upon the pinnule segments. The side plates are very well dif-
ferentiated and are often notched for the reception of the sacculi or of portions of
them; but in other cases when the sacculi are large they are altogether covered and
concealed by the side plates.

In his memoir on the stalked crinoids of the Challenger Expedition Carpenter
noted that on the disk of Poecilometra acoela the double row of transversely oblong

358 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

plates that generally mark the ambulacra are barely distinguishable. He also said
that the fertile intrapinnular portion of the genital gland is short, thick, and rounded,
and extends only over four or five of the pinnule segments.

In London I examined six specimens of Carpenter's type series and remarked that
the constriction of the lower portion of the calyx seems to be a valid character for
differentiating this species from P. scalaris.

The specimens from Siiboga stations 122 and 124 resemble each other and do not
seem to differ appreciably, in size or otherwise, from others at hand dredged by the
Challenger. In young individuals in which the radials are still about half as large as
the IBr] there is but little trace of the dorsolateral processes characteristic of the adults;
they are only slightly evident, though they can be made out as a thickened ridge in the
place they will eventually occupy. At this stage also the genital pinnules are slender and
evenly tapering, showing no trace of the lateral expansion of the segments which is so
marked a feature in the fully grown. As the radials become shorter the proximal border
of the IBri becomes produced so that it conceals the radials and the proximal edge of
the centrodorsal when the animal is viewed laterally. The dorsal surface of the radials
is gradually resorbed as the proximal margin of the IBr] is produced, so that the IBr
series and arms appear to be too large for the radials and the centrodorsal, giving the
appearance of having been glued upon them rather than of having grown out from
them. In very large specimens the produced proximal and lateral borders of the IBri,
which are typically smooth, become crenulate and scalloped.

Localities. — Challenger station 214; off the Meangis Islands (lat. 4°33' N., long.
127°06' E.); 914 meters; bottom temperature 5.44° C.; blue mud; February 10, 1S75
[P. H. Carpenter, 1880, 1884, 1887, 1888; Hartlaub, 1891; Shipley and MacBride,
1901; Minckert, 1905; Hamann, 1907; A. H. Clark, 1907, 1909, 1912, 1913, 1918;
Gislen, 1924] (9, USNM, 35659; M. C. Z., 296, 606; B. M.).

Siboga station 124; northeast of the northeastern tip of Celebes (lat. 2°27' N.,
long. 125°35' E.); 1,327 meters; stone; July 18, 1899 [A. H. Clark, 1918] (2, Amsterdam
Mm).

Siboga station 122; north of the northeastern tip of Celebes (lat. 1°58'30" N.,
long. 125°00'30" E.); 1,165-1,264 meters; stone; July 17, 1899 [A. H. Clark, 1918] (7,
Amsterdam Mus.).

Geographical range. — Between northern Celebes and Mindanao, Philippines.

Bathymetrical range. — From 914 to 1,327 meters.

Thermal range. — One record, 5.44° C.

History. — In a popular article published in 1880 Dr. P. Herbert Carpenter gave a
figure of part of a distal pinnule of a comatulid he identified only as "a new species of
Antedon from the Pacific" showing the side and covering plates. In his memoir on the
stalked crinoids of the Challenger Expedition published in 1884 he mentioned Antedon
acoela several times, giving a specific formula (page 57, footnote 4) and discussing the
peculiarities of the genital pinnules and the disk. He included a figure of the ventral
view of part of an arm showing five genital pinnules, and also a lateral and ventral view
of a single genital pinnule. He republished the figure of part of a distal pinnule given
in 1880 lengthened so as to show four and a half pinnule segments instead of three, and
thirteen side-plates instead of nine. In a paper published in 1887 Carpenter discussed
the sacculi of Antedon acoela and republished the figure of a portion of the distal pinnule.

A MONOGRAPH OF THE EXISTING CRINOIDS 359

In his memoir on the comatulids of the Challenger Expedition Carpenter described
Antedon acoela in detail and figured it on the basis of "several specimens" from station
214. In 1891 Dr. Clemens Hartlaub listed a specimen that had been presented by Car-
penter to the Gottingen Museum.

Sir Arthur E. Shipley and Prof. E. W. MacBride republished one of Carpenter's
figures in 1901, Dr. Wilhelm Minckert discussed the syzygies in 1905, and Dr. Otto
Hamann in 1907 listed Antedon acoela and republished a figure of Carpenter's.

In my first revision of the old genus Antedon published in 1907 Antedon acoela was
made the type of the new genus Poecilometra, and in my revision of the families Thalasso-
metridae and Himerometridae published in 1909 it was listed as Poecilometra acoela.
In my memoir on the crinoids of the Indian Ocean published in 1912 Poecilometra
acoela was listed and the synonymy and range were given. In 1913 I published notes
on six specimens from Challenger station 214 and compared this species with P. scalaris.
In my memoir on the unstalked crinoids of the Siboga Expedition published in 1918 1
recorded and gave notes on seven specimens from station 122 and on two from station
124.

Prof. Torsten Gislen in 1924 discussed the peculiarities of the genital pinnules on
the basis of Carpenter's description and figures.

POECILOMETRA SCALARIS (A. H. Clark)

[See vol. 1, pt. 2, figs. 118, 132, p. 79, 229, p. 186, 288, p. 221, 539-542, p. 289, 849-855, p. 412.]

Antedon scalaris A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 141 (description; Albatross
station 4918); vol. 34, 1908, pp. 437, 493.

Poecilometra scalaris A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 362 (listed); Proc.Biol.
Soc. Washington, vol. 22, 1909, p. 18 (listed); Crinoids of the Indian Ocean, 1912, p. 225 (synon-
ymy; locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 50 (comparison with P. acoela);
Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and
its significance); Unstalked crinoids of the Stto^a-Exped., 1918, p. 190 (in key; range).

Poecilometra acoela A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 265, fig. 1 (with an additional
IBr ossicle), p. 318 (southern Japan).

Diagnostic features. — The profiles of the IBr series and arm are smooth and con-
tinuous, those of the two sides making with each other an angle of about 60°; the centro-
dorsal is of moderate size with a basal diameter of 4 mm.; the cirri are about XX, 20;
and the arms are 110 mm. long.

Descrijjtion. — The centrodorsal is short columnar terminating in a stellate figure
with rounded angles and an elevated center bearing about its edge numerous small
knoblike tubercles one at the base of each of the apical cirri. The cirrus sockets are
arranged in two irregular rows and a partial third, and roughly in two or three columns
in each radial area.

The cirri are about XX, 15, about 20 mm. long, moderately stout. All the seg-
ments except the basal are longer than broad, the longest about twice as long as broad,
the distal only slightly shorter. There are no dorsal processes. The opposing spine
is minute, and the terminal claw, which is shorter, than the penultimate segment, is
stout at the base but tapers to a sharp point and is moderately curved.

The radials are concealed. The IBrt are hemispherical with the curved side
proximal. The IBr2 (axillaries) are rhombic with the lateral angles rather broadly
truncated, nearly twice as broad as long. The dorsal surface of the proximal and

360 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

lateral portions of the IBri and the lateral portions of the axillary is produced outward
into a thin flangelike border, as are the lateral edges of the first two brachials, and of
the hypozygal of the first syzygial pair, and the outer edge of the epizygal.

The 10 arms are 110 mm. long. The first two brachials are short, twice as broad
as long exclusive of the lateral flanges. The third brachial (the hypozygal of the first
syzygial pair) is oblong, about three times as broad as long. The fourth brachial
(epizygal) is triangular, tapering to a point on the inner side of the arm. The next
four brachials are triangular, about twice as broad as the median length. The ninth
brachial is oblong, nearly three times as broad as long, and those following are triangular,
about as broad as the long side, becoming distally very obliquely wedge-shaped and
longer.

Syzygies occur between brachials 3+4, again from between brachials 9 + 10 to
between brachials 12 + 13, and distally at intervals of 3 or 4 muscular articulations.

P1 is 7 mm. long with 22 segments, slender, tapering, and almost flagellate. P2 is
shorter with 15 segments of which the first seven are short and broad, the others very
small. The following pinnules to P8 or P9 have 10 segments of which the third-seventh
are bluntly keeled and much expanded dorsoventrally and bear a large gouad protected
ventrally with large plates. The terminal segments of these pinnules are minute,
the basal not especially stout. The distal pinnules are 10 mm. long with 15 moderately
elongated segments. The ambulacra are well plated.

The color in life is yellowish brown.

Note. — On one of the postradial series in the type specimen there is an additional
element in the IBr series, a small ossicle a little more than half the size of the IBi'i
interposed between the IBr! and IBr2. The first segments of the pinnules are notice-
able in being larger than usual, distantly suggesting the condition in the species of
Calometridae.

Locality. — Albatross station 4918; Eastern Sea about 90 miles west-southwest
of Kagoshima Gulf; Gwaja Shiina bearing S. 38° E., 34 miles distant (lat. 30°22'00"
N., long. 129°08'30" E.); 660 meters; bottom temperature 5.95° C.; gray sand, glo-
bigerinae, and broken shells; August 13, 1906 [A. H. Clark, 1907, 1908, 1909, 1912,
1913, 1915, 1918] (1, U.S.N.M., 22629).

History. — This species was originally described in 1907 under the name Antedon
scalaris from a single specimen from Albatross station 4918. Later in the same year
it was transferred to the new genus Poecilometra. In 1908 an aberrant IBr series
with an additional ossicle in the type specimen was described and figured, the species
being given as Poecilometra acoela, and later it was listed under the same name among
the crinoids of Japan.

In my revision of the families Thalassometridae and Himerometridae published
in 1909 Poecilometra scalaris was listed, and in my memoir on the crinoids of the Indian
Ocean published in 1912 it was again listed and the synonymy and range were given.
In my paper on the criuoids of the British Museum published in 1913 Poecilometra
scalaris was briefly compared with P. acoela from Challenger station 214. In 1915
P. scalaris was again listed as a Japanese species and the range and its significance were
discussed. In my memoir on the unstalked crinoids of the Siboga Expedition published
in 1918 scalaris was included in the key to the species of Poecilometra and the synonymy
and range were given.

A MONOGRAPH OF THE EXISTING CRINOIDS 361

Genus STROTOMETRA A. H. Clark

Antedon (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 127, and
following authors.

Charitomelra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361.

Slrotometra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 19 (diagnosis; genotype
Antedon hepburniana A. H. Clark, 1907); Crinoids of the Indian Ocean, 1912, p. 9 (absent from
Australia), p. 11 (absent from the west coast of the Malay Peninsula, the Andamans, and farther
west), p. 25 (range), p. 60 (in key), p. 226 (original reference; type); Unstalked criuoids of the
Siboga-Exped., 1918, p. 172 (in key; range), p. 191 (key to the included species). — GISLEN, Ark.
Zool., vol. 19, No. 32, Feb. 20, 1928, p. 9; Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45,
No. 11, 1934, p. 18.

Diagnosis. — The genital pinnules have the third and fourth, third-fifth, or fifth-
eighth segments much broadened, the abruptly narrower tip being shorter than the
expanded portion; the division series and arm bases are more or less recumbent, their
profile in lateral view making a wide angle with the dorsoventral axis; there are not
more than 15 cirrus segments, seldom more than 13; and the size is small, the arms
not exceeding 75 mm., and rarely being more than 45 mm. in length.

Geographical range. — From Timor and the Kei Islands northward to southwestern
Japan.

Bathymetrical range.— From 180 to 1,165 (?1,264) meters.

Thermal range. — One record from southwestern Japan, 11.28° C.

History. — The genus Strotometra was established in 1909 with the genotype Antedon
hepburniana A. H. Clark, 1907, including also Carpenter's Antedon parvipinna, both
of which had been previously referred to Charitometra. The status of the genus has
remained unchanged except for the addition of two new species, ornatissimus and
priamus, in 1912.

KEY TO THE SPECIES IN THE GENUS STROTOMETRA

a1. Distal border of the second brachial everted, standing out at right angles to the dorsoventral
axis of the arm as an enormous thin rounded or fan-shaped crest with a rounded or broadly
scalloped edge, sometimes divided in the middle, which may reach 1.5 mm. in height, the height
being three or four times the greater (outer) length of the ossicle; the fourth brachial (epizygal
of the first syzygial pair) has a similar crest nearly, if not quite as large; the fifth brachial has a
crest about half as high and more irregular; the sixth has a strongly produced and thickened
distal edge which is coarsely scalloped; the following brachials are of the normal type with
slightly produced and finely spinous distal borders (east of the northeastern end of Celebes;

1,165-1,264 meters) ornatissimus (p. 326)

a3. None of the brachials have everted and extravagantly developed distal borders.

6'. Cirri slender with all the segments beyond the second much longer than broad, the longest
nearly three times as long as the median width, and moderately constricted centrally; genital
pinnules with the fifth-eighth segments broadened, so that the expanded portion is preceded
by a distinct peduncle; no carination of the IBr series and arms (Kei Islands to southwestern

Timor; 245-595 meters) priainus (p. 363)

ti3. Cirri short and stout, the longest segments very little or not at all longer than broad and not
constricted centrally; genital pinnules with the third-fourth or third-fifth segments broadened
so that the expanded portion appears sessile; IBr series and arms more or less distinctly
carinate.

c1. PI with 20-22 segments, 6 mm. long; pinnules in the proximal portion of the arms smooth or
nearly so; larger, arms 60-75 mm. long; cirri with 11-15 segments (Kei Islands to south-
western Timor; 245-520 meters) parvipinna (p. 365)

843803 — 50 24

362 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

c2. PI with 10-11 segments, 3.5 mm. long; pinnules in the proximal portion of the arms with
conspicuously flaring and overlapping distal ends, appearing very rough; smaller, arms 45
mm. long; cirri with 10 segments (southwestern Japan; 180-243 meters).

hepburniana (p. 368)

STROTOMETRA ORNATISSIMUS A. H. Clark

PLATE 20, FIGURE 65
[See also vol. 1, pt. 1, figs. 101, 102, p. 163.]

Slrotometra ornatissimus A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 82 (description;
Siboga station 122); Unstalked crinoids of the Siboga-Exped., 1918, p. ix (ornamentation), p. 191
(in key; range), p. 192 (detailed description; station 122), fig. 10, p. 192, fig. 11, p. 193, p. 273
(listed), pi. 24, fig. 70.

Strotometra ornatissimns A. H. CLARK, Unstalked crinoids of the Ssbojo-Exped., 1918, p. 191.

Diagnostic features. — The distal edge of the second and fourth, and to a lesser
extent the fifth, brachials is everted and produced at right angles to the longitudinal
axis of the arm, standing up as a high, thin, rounded or fan-shaped crest; the axillaries
are chevron-shaped instead of triangular; and the fourth and fifth cirrus segments are
about three times as long as the median width, strongly constricted centrally with
expanded distal ends.

Description. — The centrodorsal is flattened-hemispherical, 2.5 mm. in diameter at
the base ; the dorsal pole is slightly convex. The cirrus sockets are arranged in one and
a partial second marginal row.

The cirri are about XV (there are 22 cirrus sockets but some are not full size) ; the
longest cirrus stunip is 4.5 mm. long to the distal dorsal edge of the fifth (the last
remaining) segment. The first segment is about twice as broad as long; the second
has the median length about equal to the median breadth and is centrally constricted
with the distal border produced, especially ventrally where it overlaps the proximal
end of the segment succeeding; the third is about twice as long as the proximal width,
strongly constricted centrally with the distal end prominent as in the second; the fourth
is about three times as long as the median width but otherwise similar to the third;
and the fifth is similar to the fourth but not quite so much constricted centrally and
hence appearing slightly broader in lateral view.

The radials are just visible over the rim of the centrodorsal. The IBrj are short,
about four times as broad as the median length, with the proximal border produced
into a thin straight margin and the lateral borders slightly more produced and turned
outward. The IBr2 (axillaries) are broadly chevron-shaped with the lateral edges,
which are half again as long as those of the IBri, turned outward, unmodified, or with
two or three broad scallops ; the lateral thirds of the proximal border are produced and
extended downward over the distal border of the IBr^ these have a scalloped or tuber-
cular edge which is nearly parallel to the concave distal edge opposite. The distal edges
of the axillaries are plain and unmodified.

The 10 arms are about 40 mm. long. The first brachials have the proximal and
distal edges parallel, the outer edge slightly produced and faintly scalloped, and the
inner edges in apposition, in then- distal half everted and scalloped; a corresponding
length of the inner portion of the distal edge is similarly everted and scalloped, and
the inner distal angle is rounded and produced into a thin rounded process with a more
or less scalloped border; the proximal border and the distal border except for the part

A MONOGRAPH OF THE EXISTING CRESTOIDS 363

mentioned are unmodified. The second brachial is about the length of the first, and
is slightly wedge-shaped; the distal edge is everted and stands out at right angles to
the axis of the arm in the form of an enormous thin rounded or fan-shaped crest with a
rounded or broadly scalloped edge, sometimes divided in the middle, which may reach
1.5 mm. hi height, or from three to four tunes the greater (outer) length of the ossicle;
the proximal outer corner of the ossicle is slightly produced backwards over the distal
outer corner of the first brachial, and is scalloped or slightly tuberculated. The pro-
duced inner distal angles of the first brachials reach as far as the base of the crest.
The third brachial (the hypozygal of the first syzygial pair) is oblong, very short, five
or six times as broad as long, and is unmodified. The fourth brachial (the epizygal of
the first syzygial pair) is very short, little if any longer than the third (hypozygal),
oblong, with the distal border everted and produced into an enormous crest similar to,
and nearly or quite as large as, that on the second brachial. The fifth brachial is
slightly wedge-shaped, with a crest about half as high as that on the brachial preceding
and more irregular. The sixth brachial has a strongly produced and thickened
distal edge which is coarsely scalloped. The seventh brachial is slightly wedge-shaped,
from two to two and one-half times as broad as long, with the distal edge slightly pro-
duced in the direction of the axis of the arm and finely spinous. After the tenth or
twelfth the brachials become triangular, about as long as broad, and after four or five
more very obliquely wedge-shaped and longer than broad, and distally longer and less
obliquely wedge-shaped. Beyond the sixth the brachials are almost smooth, with only
slightly produced and finely spinous distal edges.

PI is about 4.5 mm. long with about 13 segments of which the first two are broader
than long with rounded dorsal processes, the third is slightly longer, the fourth is about
as long as broad, and those beyond the seventh are slightly longer than broad. P2 is
about 4 mm. long, composed of 12 segments, and is similar to PI but with slightly longer
distal segments. The genital pinnules are about 4 mm. long with the fourth, fifth,
and sixth segments enormously expanded, roofing over the gonads, which are also
protected ventrally by strong calcareous plates of irregular shape; the seventh and
following segments are small and slender. On one arm Pj and PZ, as well as the
pinnules following, bear gonads.

Locality— Siboga station 122; Celebes Sea (lat. 1°58'30" N., long. 125°00'30" E.);
1,165-1,264 meters; stone; July 17, 1899 [A. H. Clark, 1912, 1918] (1, Amsterdam Mus.).

History. — This species is known only from the single specimen dredged by the
Siboga at station 122, originally described in 1912 and redescribed and figured in 1918.

STROTOMETRA PRIAMUS A. H. Clark

PLATE 31, FIGURE 97
[See also vol. 1, pt. 2, fig. 230, p. 188.]

Strotometra priamus A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 81 (description;
Siboga station 266); Unstalked crinoids of the Siboga-Exped., 1918, p. 192 (in key; range), p.
194 (detailed description; stations 266, 297), p. 275 (listed), pi. 24, figs. 64, 65.

Diagnostic features. — The cirri are slender, all' the segments beyond the second
much longer than broad, the longest being nearly three times as long as the median
width and constricted centrally; the expanded portion of the genital pinnules is pre-

364 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

ceded by usually four unmodified segments so that it appears pedunculated ; and there
is no carination of the IBr series and arms.

Description.— The centrodorsal is very low, low-hemispherical or almost discoidal,
from 1.5 to 2.0 mm. in diameter. The cirrus sockets are arranged in one and a partial
second irregular and closely crowded rows.

The cirri are XVII, 11-12 (usually 11), from 8 to 11 mm. long, slender, with
elongated segments. The first segment is very short, dorsally expanded into a rounded
knoblike process; the second is not quite so long as broad; the third is twice as long as
the median width; the fourth and fifth are nearly three times as long as the median
width; and the remainder are very slightly shorter, becoming a trifle longer again,
about two and one-half times as long as broad, on the antepenultimate and penultimate.
The penultimate segment is of lesser width in lateral view than those preceding. The
third and following segments are moderately constricted centrally with prominent distal
ends, this feature decreasing distally. The segments bear no dorsal spines or other
prominences. The opposing spine is prominent, terminal, directed obliquely forward;
its proximal profile is convex, its distal profile concave, and its base occupies only
slightly more than one-third of the dorsal surface of the penultimate segment. The
terminal claw is about as long as the penultimate segment and is moderately stout and
moderately and evenly curved.

The ends of the basal rays are visible as small but prominent tubercles in the angles
of the calyx.

The radials are entirely concealed by the centrodorsal. The IBr, are short, about
four times as broad as long in the median line; the proximal border is slightly produced,
slightly convex, but usually becoming straight in the lateral quarters; the lateral edges
are in close apposition with those of their neighbors, and are widely divergent and
produced and everted as in Glyptometra lateralis; the distal edge is sometimes obscurely
scalloped in the lateral thirds, the median third being slightly excavated for the recep-
tion of a rounded posterior process from the axillary. The IBr2 (axillary) is exceedingly
short, about two and one-half times as broad as long; its lateral edges resemble those
of the IBri but are only about half as long.

The 10 arms are about 40 mm. long. The first brachials are in close apposition
with their neighbors both internally and externally; their proximal and distal borders
are parallel, the proximal being slightly everted; their outer borders are produced and
everted like the outer borders of the preceding ossicles; the inner borders are similarly
everted, though not so much so; the synarthrial tubercles, though small and well
rounded, are rather prominent. The second brachials are similar to the first, but are
about twice as long externally as internally. The first syzygial pair (composed of
brachials 3+4) is roughly oblong, about two and one-half tunes as broad as long, with
the lateral edges modified as in the ossicles preceding. The next three brachials are
wedge-shaped, about twice as broad as the maximum length, with the dorsal surface
usually concave and the distal edge therefore prominent. After the tenth the brachials
become triangular and about as long as broad, later very obliquely wedge-shaped, and
toward the ends of the arms twice as long as broad. Beyond the second syzygy the
brachials have slightly produced and very finely spinous distal ends. There is no
carination of the division series and arms.

A MONOGRAPH OF THE EXISTING CRINOIDS 365

PI is slender and delicate, 6 mm. long with 35 segments of which the seventh or
eighth and following are about as long as broad ; except for the absence of the expansion
of the first two segments it resembles P, in Calometra. P2 in the type specimen is 6
mm. long with 18 segments of which the sixth-eleventh are greatly produced ventrally
forming a roof over the gonads, which are further protected by a heavy ventral plating;
the seven terminal segments are very small and delicate. P3 is similar, 4.5 mm. long
with 14 segments of which the sixth-tenth are expanded to protect the gonads. P4
is 4 mm. long with 13 segments of which the fifth-ninth are expanded. P6 is 3 mm. long,
small and moderately stout, with 10 segments none of which are expanded. The
pinnules following gradually increase in length, the distal pinnules being 5 mm. long
with 11 or 12 segments. In other specimens the genital pinnules usually have the
fifth-eighth segments expanded, or in small specimens the fifth-sixth or fifth-seventh.

Notes. — One of the specimens from the Danish Expedition to the Kei Islands
station 1 has the arms 45 mm. long; the other two are smaller.

The specimen from the Danish Expedition to the Kei Islands station 56 has the
arms 45 mm. long and the cirri 10 mm. long with 10-11 (usually 10) segments.

Localities.— Siboga station 266; Kei Islands (lat. 5°56'30" S., long. 132°47'42"
E.); 595 meters; gray mud with coral and stones; December 19, 1899 [A. H. Clark,
1912, 1918] (39, U.S.N.M., E. 427; Amsterdam Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 1; 370-400
meters; mud; March 30, 1922 (3, U.S.N.M., E. 3151; C. M.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 245 meters;
mud; May 10, 1922 (1, C. M.).

Siboga station 297 ; Lesser Sunda Islands, north of Rotti (lat. 10°39' S., long. 123 °40'
E.); 520 meters; soft gray mud with a brown upper layer; January 27, 1900 [A. H.
Clark, 1918] (1, Amsterdam Mus.).

Geographical range. — From the Kei Islands to the vicinity of southwestern Timor.

Bathymetrical range. — From 245 to 595 meters.

History. — Strotometra priamus was originally described in 1912 from a specimen
from Siboga station 266. It was redescribed and figured in 1918 when 39 specimens
from station 266 and one from station 297 were recorded.

STROTOMETRA PARVTPINNA (P. H. Carpenter)

[See vol. 1, pt. 2, fig. 231, p. 191.]

Antedon parvipinna P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 127 (de-
scription; Challenger station 192), pi. 15, fig. 9. — HARTLAUB, Bull. Mus. Comp. Zool., vol. 27,
No. 4, 1895, p. 130 (systematic and bathymetrical relationships). — HAMANN, Bronn's Klassen
und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1578 (listed). — A. H. CLARK, Crinoids
of the Indian Ocean, 1912, p. 33 (identity).

Charitomelra parvipinna A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed).

Strotometra parvipinna A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 20 (listed); Crinoids
of the Indian Ocean, 1912, p. 33 (identity), p. 226 (synonymy; locality); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 50 (published reference to specimen in the B. M.; Challenger station
192; characters, and comparison with S. hepburniana) ; Unstalked crinoids of the Stboya-Exped.,
1918, p. ix (relationship with S. hepburniana), p. 192 (in key; range), p. 194 (references; notes;
Stas. 254, 297), pp. 274, 275 (listed).— GISLEN, Ark. Zool., vol. 19, No. 32, Feb. 20, 192S, p. 9,
No. 44 (notes); Kungl. Fysiogr. Sallsk. Hand!., new ser., vol. 45, No. 11, 1934, p. 18.

366 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Diagnostic features. — The cirri are short and stout with the longest segments little,
if any, longer than broad and not constricted centrally; the expanded portion of the
genital pinnules is preceded by two unmodified segments so that it appears sessile;
the pinnules on the proximal portion of the arms are smooth or nearly so; PI is 6 mm.
long with 20-22 segments; the arms are 60-75 mm. long; and the cirri have 11-15
segments.

Description. — The centrodorsal is discoidal. According to the figure the cirri
are arranged in a partially double marginal row.

The cirri are about XV, about 15; the segments are stout, the fifth and sixth slightly
longer than broad.

Carpenter says that minute plates, probably the basal rays, rest upon the inter-
radial angles of the centrodorsal and separate the IBri.

The IBri are nearly oblong, and are in close lateral contact beyond the ends of the
basal rays. The IBr2 (axillaries) are short and broad with very open angles and are in
close apposition. Both the elements of the IBr series have traces of a median keel
which is continued on to the arm bases.

The 10 arms are probably 60 mm. long. The first brachials are nearly oblong, with
the outer sides flattened. The inner sides of the second and third (hypozygal) brachials
are also flattened. The brachials after the eighth are triangular, at first considerably
broader than long, but gradually becoming more nearly as long as broad, and finally
wedge-shaped.

Syzygies occur between brachials 3+4, again from between brachials 9 + 10 to
between brachials 13 + 14, and the distal intersyzygial interval is from 6 to 10 muscular
articulations.

PI and Pa are relatively small and are of tolerably equal size, with little more than
12 short segments. P2 and Pb have longer segments, and the pinnules of the seventh
and following brachials have the third and next two or three segments considerably
expanded so as to enclose the gonads, which are also protected by plates. The fourth
segment is larger than the rest, but not markedly so.

The disk is 4 mm. in diameter. The disk and arms are distinctly, though not
extensively, plated. The pinnule ambulacra have fairly defined side plates with inter-
vening sacculi, which are also abundant in the plating over the gonads.

The color in alcohol is white.

Notes. — Carpenter said that in his specimen PI is relatively shorter and much
less flagellate than in Glyptometra tuberosa, consisting of a smaller number of segments
and having an altogether stiffer appearance.

In a specimen at hand P! is 6 mm. long with 20-22 segments; it tapers rapidly in
the first six segments and is very slender from the seventh segment onward. It is
possible that in Carpenter's specimen PI and Pa were broken. In the present specimen
P2 is about as long as P! with 13 segments; it tapers evenly from the base to the tip and
because of this appears considerably stouter than PI. The genital pinnules have the
third-fifth segments much expanded. The pinnule segments are without produced
and prominent distal ends. The arms are faintly carinate. None of the cirrus seg-
ments are longer than broad.

After examining the type specimen in the British Museum I wrote that this species
is closely related to S. hepburniana; it is a large form with much less expanded genital

A MONOGRAPH OF THE EXISTING CRINOIDS 367

pinnules. I should have said that the enlarged segments of the genital pinnules are
not broadened laterally as in S. hepburniana but then1 sides are produced downward at
a considerable angle so that in a dorsal view they appear to be much less expanded.
There is a delicate median carination on the elements of the IBr series and on the first
two brachials which is easily traceable all along the arm. P2 is rather more like PI
than like P3, though it is larger and has some of the characteristics of the latter. There
are 11-13 cirrus segments.

Gislen wrote of the same specimen that the cirri have about 15 segments as stated
by Carpenter.

Five of the specimens from the Danish Expedition to the Kei Islands station 56
show the following features: (1) Arms about 70 mm. long, 11-12 cirrus segments;
(2) arms about 70 nun. long, 12 cirrus segments; (3) arms about 55 mm. long, 12 cirrus
segments; (4) arms about 75 mm. long, 11-12 cirrus segments; (5) arms about 75 mm.
long, 11 cirrus segments. The four other specimens are similar.

The largest specimen from Siboga station 297 is relatively large and stout with
the arms 75 mm. long. The surface of the dorsal pole of the centrodorsal and of the
radials and the IBr] is very thickly covered with irregular tubercles so that it appears
more or less spongelike. The borders of the ossicles of the IBr series and of the first
two brachials are thickened and slightly everted. The IBr2 (axillary) has a rather high
median keel. The following ossicles have a prominent rounded tubercle which becomes
a low broad carinate process on the triangular brachials. The cirri are XVI, 12-13;
the longest proximal segments (the third and fourth) are slightly longer than broad,
and the distal segments are slightly broader than long. P! has 17-19 segments.

Another specimen similar to the preceding but with the arms only 60 mm. long has
the modification of the surface of the radials and IB^ not so strongly marked. The
cirri are X, 12.

A third is similar to the last, but the modification of the surface of the radials is
scarcely noticeable. The cirri are X, 11-12. All the others except the following
resemble this.

A very interesting individual with the arms 65 mm. long has the IBri with a high
rounded median keel and everted lateral borders. On either side of the median keel
there are from two to five high rounded tubercles. The type of ornamentation as a
whole strongly suggests the condition found in Glyptometra tuberosa. The IBr axillary
has the borders slightly everted and the distal borders margined with confluent tubercles
which rapidly diminish in width from the median line to the outer angles.

Localities.— Siboga station 254; Kei Islands (lat. 5°40' S., long. 132°26' E.); 310
meters; fine gray mud; December 10, 1899 [A. H. Clark, 1918] (1, Amsterdam Mus.).

Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 245 meters;
mud; May 10, 1922 (9, U.S.N.M., E. 3142; C. M.).

Challenger station 192; near the Kei Islands (lat. 5°49'15" S., long. 132°14'15"
E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hartlaub, 1895;
Hamann, 1907; A. H. Clark, 1907, 1909, 1912, 1913, 1918; Gislen, 1928, 1934] (1,
B. M.).

Siboga station 297; Lesser Sunda Islands, north of Rotti (lat. 10°39' S.,long. 123°40'
E.); 520 meters; soft gray mud with a brown upper layer; January 27, 1900 [A. H.
Clark, 1918] (6, U.S.N.M., E. 418; Amsterdam Mus.).

368 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Geographical range. — From the Kei Islands to southwestern Timor.

Bathymetrical range. — From 245 to 520 meters.

History. — Antedon parvipinna was described and figured by Dr. P. Herbert Car-
penter in his report on the comatulids of the Challenger Expedition published in 1888
on the basis of a single specimen from station 192. Dr. Clemens Hartlaub in 1895
discussed its systematic and bathymetrical relationships, and in 1907 it was listed by
Dr. Otto Hamann.

In my first revision of the old genus Antedon published in 1907 parvipinna was
removed to the new genus Charitometra, and in my revision of the families Thalasso-
metridae and Himerometridae published in 1909 it was assigned to the new genus
Strotometra. In my memoir on the crinoids of the Indian Ocean published in 1912
Strotometra parvipinna was listed and the synonymy and locality were given. In
1913 I published a brief note on the type specimen from Challenger station 192 which I
had examined at the British Museum in 1910, comparing it with S. hepburniana. In
1918 in my memoir on the unstalked crinoids of the Siboga Expedition parvipinna
was included in the key to the species of Strotometra , and one specimen was recorded
from station 254 and six from station 297, notes being given on some of the latter.

Prof. Torsten Gislen in 1928 gave additional notes on the type specimen in the
British Museum, and hi 1934 he classified the arm division of Strotometra parvipinna
as belonging to the Monachometra fragilis type I.

STROTOMETRA HEPBURNIANA (A. H. Clark)

PLATE 31, FIGURES 95, 96; PLATE 32, FIGURE 104
[See also vol. 1, pt. 2, figs. 232, p. 192, 808-811, p. 385.]

Antedon hepburniana A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 139 (description; Albatross
station 4890).

Charitometra hepburniana A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361 (listed) ;
Proc. U. S. Nat. Mus., vol. 34, 1908, p. 318 (Japan); Geogr. Journ., vol. 32, No. 6, 1908, p. 603
(type of a non-oceanic group).

Strotometra hepburniana A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 20 (listed) ; Vid.
Medd. Nat. Foren. K0benhavn, 1909, p. 187 (south of the Goto Islands, 100 fathoms; descrip-
tion; comparison with the type) ; Crinoids of the Indian Ocean, 1912, p. 226 (synonymy; locality) ;
Proc. Biol. Soc. Washington, vol. 26, 1913, p. 179 (range in eastern Asia); Smithsonian Misc.
Coll., vol. 61, No. 15, 1913, p. 50 (comparison with S. parvipinna); Journ. Washington Acad.
Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance) ; Unstalked
crinoids of the Siboja-Exped., 1918, p. ix (relationship with S. parvipinna), p. 192 (in key;
range), p. 194 (references); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, pi. 2, fig. 28 (side
plate).

Diagnostic features. — The cirri are short and stout, the longest segments slightly
longer than broad and not constricted centrally; the expanded portion of the genital
pinnules is preceded by two unmodified segments so that it appears sessile ; the segments
of the pinnules in the proximal portion of the arms have conspicuously flaring and over-
lapping distal ends so that the pinnules appear very rough; PI is 3.5 mm. long with
10-11 segments; the arms are 45 mm. long; and the cirri have 10 segments.

Description. — The centrodorsal is low-hemispherical without interradial processes
and with the large dorsal pole roughened. There is a single row of 10 cirrus sockets,
two to each radial area.

A MONOGRAPH OF THE EXISTING CRINOIDS 369

The cirri are X, 10, about 7 mm. long, short and stout. The first segment is very
short, the second is about twice as long, the third is about twice as long as the second,
and about as long as broad. The segments following are somewhat longer than broad.
The penultimate segment bears a. prominent opposing spine. The terminal claw is
about as long as the penultimate segment and is stout and moderately curved.

The ends of the basal rays are visible as interradial tubercles.

The radials are short and bandlike with curved proximal and distal borders; the
lateral edges are raised into blunt tubercles. The IBr! aro somewhat longer, about
four times as broad as long, and arc bluntly carinate. The IBr2 (axillaries) are short,
low-triangular, about three times as broad as long, with a low blunt median keel. The
ossicles of the IBr series and first four or five brachials have slightly flattened sides.

The 10 arms are 45 mm. long. The earlier brachials are oblong with a blunt
median keel, becoming wedge-shaped after the fifth, after the ninth nearly triangular
and somewhat broader than long, and elongate and wedge-shaped again distally.

Syzygies occur between brachials 3+4, again at about brachials 11 + 12, and
distally at intervals of 4 or 5 muscular articulations.

PI is 2.5 mm. long with 10-13 short segments of which the first four or five are
considerably broader than the others; the segments are about as long as broad, rounded
trapezoidal in shape, making the distal corners very prominent. Pa is similar to Pt
but slightly shorter with the basal segments not so much enlarged. P2 is 2 mm. long
with 6 segments of which the third and fourth are greatly expanded laterally. The
next five pinnules are similar to P2 with t> or 7 segments of which the third and fourth
and sometimes also the fifth are greatly expanded laterally and support the large
globose gonads. Distally the pinnules become uniformly tapering and slender, reaching
3.5 mm. in length with about 12 segments of which the first is short, the second is
about as long as broad, and the remainder are somewhat longer than broad.

The disk is scantily plated. Side and covering plates are well developed along the
brachial and pinnule ambulacra, and the gonads are protected ventrally by a pavement
of large irregular plates.

The color in life is bright yellow.

Notes. — The specimen from south of the Goto Islands in the Copenhagen Museum
is considerably larger than those obtained by the Albatross in the same general region.
The arms are about 60 mm. long. P2 is more nearly like PI than in the Albatross speci-
mens, in which P2 resembles P3. All the brachials except the first three or four have
strongly produced and overlapping distal ends. The color of the specimen is dull
orange, possibly due to a slight alkalinity in the containing alcohol.

Localities. — Albatross station 4890; 10 miles southwest of the Goto Islands; Ose
Saki Light bearing N. 2° W., 10 miles distant (lat. 32°26'30" N., long. 128°36'30"
E.); 243 meters; bottom temperature 11.28° C.; rocky bottom; August 9, 1906 [A. H.
Clark, 1907, 1908, 1909, 1912, 1913, 1915, 1918, 1921] (5, U.S.N.M., 22635 [type],
35692).

Eastern Sea south of the Goto Islands (lat. 32°10' N., long. 128°20' E.) ; 180 meters;
Captain Schonau, April 23, 1898 [A. H. Clark, 1909, '1913, 1915, 1918] (1, C. M.).

Eastern Asia (1, C. M.)

Geographical range. — Known only from the Eastern Sea south of the Goto Islands.

Bathy metrical range. — From 180 to 243 meters.

843803—50 26

370 BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Thermal range. — One record, 11.28° C.

History. — Antedon hepburniana was originally described in 1907 from a specimen
dredged by the Albatross at station 4890. In my first revision of the genus Antedon
published later in the same year hepburniana was removed to the new genus Charito-
metra, and in 1908 Charitometra hepburniana was listed as a Japanese species. In
another paper published toward the end of 1908 Charitometra hepburniana was given as
a representative of a nonoceanic group of comatulids.

In my revision of the families Thalassometridae and Himerometridae published
in 1909 Antedon hepburniana was made the type of the new genus Strotometra, and
later in the same year a specimen of Strotometra hepburniana, was recorded from south
of the Goto Islands and notes were given on it. In my memoir on the crinoids of the
Indian Ocean published in 1912 Strotometra hepburniana was listed and the synonymy
and range were given, and this information was repeated in 1913. In 1913 also, in a
paper on the crinoids of the British Museum, S. parvipinna was compared with S.
hepburniana. In 1915 S. hepburinana was listed as a southern Japanese species, and
the range and its significance were discussed. In my report on the unstalked crinoids
of the Siboga Expedition published in 1918 hepburniana was included in the key to the
species of Strotometra, the synonymy and range were given, and its relationship to
S. parvipinna was mentioned. In a popular article on sea lilies and feather stars
published in 1921 the side plates of Strotometra hepburniana were figured, the two
figures given (under one number) being copies of figures 810 and 811 on page 385 of
Part 2.

U. S NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 1

1, Stenomftra snelliuii: Type specimen from ff'illtbrorJ Snellius station 253* (L.M.).

2, 3, Stenomttra quinquicostata: 2, Type specimen of Sttnomttra dipla* fmni Rutii Strait in 183 meters, X 2 (B.M.);
3, specimen of S. crisiata from Albatross station 5275, X 2 (L .S.X.M., 55598).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 2

4, 6, 7, Stenometra quinquccostata: 4, Type specimen oi Stenometra crislala from .-llbalross station 5275,

(U.S.N.M., 27501); 6, 7, specimen from between Timor and Rotti in 183 meters, X 2 (B.M.).
5, Stenometra diadema: Specimen from the Eastern Sea near Nagasaki in 311 meters (C..VI.)-

X 2

U. S. NATIONAL MUSEUM

BULLETIN 82 PART 4C PLATE 3

12

8, Stylometra spinifera (I. .S.X.M.).

9, Cosmiomelra delicala: Tj pe specimen frnin Albatross station 396.) (U.S.X.M., 22690).

10, 11, Cosmiomelra cnnifera: 10, Type specimen from Japan (Berl. Mus., 2S30); 11, additional cirri from the

n pe specimen.

12. Daidalnniftra arachnnidts: I'yi'c specimen of Stenomdra acuta from Siboga station 294, X 2 (Amsterdam
Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 4

13

13, Daidalomelra liana: Type specimen from Albatross station 4903, X 2 (U.S.N.M., 22(>32).

14, Coimiometra iole: Type specimen from Zamboanga, Mindanao, Philippines, in 292-365 meters (C.M.).

15, Cosmiomelra conifera: Type specimen from Japan, ventral view (Berl. Mus., 2830). (See pi. 3, figs. 10, 11.)

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 5

17

16, CosmiomttTa philippinensu: Type specimen <>t Cosmiomttra helene from Sih"<j,i Mation 253, X 2 (Amster-

dam Mus.).

17, Cosmiomttra leilae: Type specimen from Investigator station 465, X 2 (I.M.).

18, Stiremetra decora: Type specimen from Albatross station 4107, X 2 (U.S.N.M., 36079).

19, 20, Parametra orion: Pinnules from a specimen from Albatross station 4934; 19. proximal pinnules; 20.
pinnules, X 2. (Entire specimen shown on pi. 8, fig. 27.)

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 6

23

22

21, Cosmiometra aster: Type specimen from Albatross station 5088, X 2 (U.S.N.M., 22636).

22, Cosmiometra philippinensis: Specimen from Albatross station 5523 (U.S.N.M., 27497).

23, Cosmiometra leilae: Cotype from Investigator station 465, X 2 (f.M.).

24, Horaeometra duplex: Specimen from Albatross station 2346, X 2 (U.S.N.M., 22673).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 7

25

25, Paraniflra granulala: Specimen from .llbatross station 5367, X 2 (U.S.X.M., 35601).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 8

26, Parametra compressa: Specimen from Albatross station 5617, X 2 (U.S.N.M., 35976).

27, Parametra orion: Specimen from Albatross station 4934, X 2 (U.S.N.M., 35565). (Pinnules of this specimen

shown on pi. 5, figs. 19, 20.)

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 9

29

28, Paramelra fishsri: Type specimen from Albatross station 4122. • 2 (I'.S.N.M.. 22686).

29, Paramelra ajax: Type specimen from the Malay Archipelago (B.M.)-

U- S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 10

33

30, Parametra orion: Specimen from southern Japan.
31, 32, Paramftra granu/ala: Specimens from Albatross station 5367 (U.S.N.M., 35601).

33, Cosmioniftra crassicirra: Type specimen from Albatross station 3882 (U.S.N.M., 22689).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 11

35

36

34. Lissiimelra albnflava: Type specimen from Albatross station 4936, X 2 (U.S.X.M.. 22<o4).
35, 36, Crotalometra ruttica: 35, Type specimen of Crolalumetra eriJanella fmni off Great Nicobar Island in 1,901
2,047 meters (B.M.); 35, specimen from off Madras in 1.097 meters (B.M.).

U. S. NATIONAL MUSEUM

BULLETIN 82, PART 4C PLATE 12

c

37

37, Aglaomelra fropinqua: Specimen from Albatross station 5424, X 2 (U.S.N.M., 3557s).

U S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 13

38

V '''. .l^lai'inelrn ra/iila: 38, Type specimen of Crotalumrlra eupedata from Albatross station 5236, X 2 (U.S.N.M.,

25462); }f>. lower and middle pinnules from tile same specimen, X 2.
40, Afjaometra sulcata: Type specimen from Siboga station 161 (Amsterdam Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 14

43

41. Oceanomelra gigantea: Type specimen from Albatross station 3985 (U.S.N.M., 22687)

42, 43, Oceanome/ra magna: 42, Specimen from south of western Timor in 256-292 meters (B.M.); 43, type speci-
men from Siboga station 251 (Amsterdam Mus.).
44, Stiremetra perplexa: Type specimen from Siboga station 211 (Amsterdam Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 15

45, 46, Ocianomttra annandalei: 45, Cotype trom the Malay Archipelago in 55 meters, X 2 (L.S.X.M., 35577);

46, type specimen from the same locality (I.M.).
47, Atfaomelra propinqua: Type specimen of Aglaomttra vera from Siboga station 173 (Amsterdam Mus.).

U. S- NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 16

48, 49, Leilametra necopinata: 48, Type specimen from south of Lombok in 1,097 meters (B.M.); 49, pinnules
of the same specimen.

U. S. NATIONAL MUSEUM

BULLETIN 82 PART 4C PLATE 17

55

50-52, Thalassomttra villosa: 50, Type specimen from Albatross station 47X0, • 2 il'.S.N.M.. 22fiiO); 51. 52,
cotypes from the same locality.

53,54, Thalassometra attenuata: 53, Specimen from off Mozambique in 914 meters, X 2 (B.M.); 54, type speci-
men from south of Kurrachi in 1,398 meters (I.M.).
55, Thalafsomftra margaritifera: Type specimen from Siboga station 45 (Amsterdam Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 18

58

57

56, 57, Thalassometra peripolos: 56, Type specimen from south of the Nicobar Islands in 1,024 meters, X 2
(B.M.); 57, specimen from southeast of Car Nicobar (B.M.).

58, Crolalometra rustica: Type specimen of Thalassometra marginalis from Siboga station 226, X 2 (Amsterdam

Mus.).

59, Thalassometra hirsuta: Type specimen from Albatross station 5445, X 2 (U.S.N.M., 27500).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 19

60

60. Chondrometra robusla: Specimen from Siboga station 297, X 2 (U.S.N.M., E. 464).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 20

65

61

-:

62

63

61, Monachometra fatula: Specimen from Albatross station 5356 (U.S.N.M., 35704).
62, 63, Monachomttra fragilis: Type specimen from Siboga station 166 (Amsterdam Mus.).

64, Chlorometra gam/liana: Type specimen from Albatross station 4S94 (U.S.N.M., 22633).

65, Strotometra ornatissimus: Type specimen from Siboga station 122, X 2 (Amsterdam Mus.).

U. S- NATIONAL MUSEUM

BULLETIN 82, PART 4C PLATE 21

66

67

66, 67, Glyptomftra liinorensis: 55. Cotype from Sibaga station 297, X 2 (L'.S.X.M.. E. 424); '.7. i> p<- specimen

from Sibiiga station 297 (Amsterdam Mus.).
68, Glyptometra crassa: Type specimen from Siboga station 259 (Amsterdam Mns.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 22

69

69, Glyptomelra tuberosa: Specimen from dtbatross station 5367, X 2 (U.S.N.M, 35668).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 23

70

70-72, Clvftiimfira distincta: 70, Type specimen of I'afhylometra selfiif from Albatross station 552.) (U.S.N.M.,
27504); 71, specimen from the Danish Expedition to the Rei Islands (C.M.); 72, type specimen of Chari-
liimetra .tmitlii from Albatross station 5123 (U.S.N.M.. 25448).

Lu

LIBRARY

#

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 24

73

73, Glyptometra distincta: Specimen from Albatross station 5523 (U.S.N.M., 36001).
74, 75, Glyptometra investigatoris: 74, Specimen from Siboga station 254 (Amsterdam Mus.); 75,
Siboga station 297 (Amsterdam Mus.).

specimen from

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 25

77

76-78, Glyptometra investigatoris: 76, Type specimen from the Malay Archipelago in 55 meters (I.M.); 77, specimen
from Albatross station 5325 (U.S.N.M., 27?0.i); 78, specimen from the Bali Sea in about 200 meters
(Buiten7.org, Java, Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82, PART 4C PLATE 26

79

80

81

. Glyptomelra macilenta: 79, Type specimen from the Laccadive Islands in 1,288 meters (I.M.); 80, specimen
from south of Timorlaut in 914 meters (B.M.); 81, type specimen of Perissometra occidentalis from off the
Seychelles in 1,462 meters (B.M.).

U. S- NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 27

82, 83, Glyptometra levigala: 82, Type specimen from .•l/lmrrms station 5256. X 2 (U.S.N.M.. 25464); 83, specimen
from Albatross station 5367 (U.S.X.M., 35X'<-,;

U. S. NATIONAL MUSEUM

BULLETIN 82, PART 4C PLATE 28

84-86, Glyplomttra Lita: 84, Specimen from off Misaki, Japan (U.S.X.M., 35684); 85, Type specimen from Albatross
station 4918 (U.S.N.M., 22628); 86, Specimen from Albatross station 491S, X 2 (U.S.NAI., 22628).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 29

87, Glyflomdra l.iteralis (U.S.X.M.).

88,Glyptomelra lata: Cotype from .-Hbairuss station 4918 (U.S.N.M., 22'. 2M.

89, Glyptometra intenusta: T)-pe specimen from off South Andaman Island in 1,040 meters (I.M.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART AC PLATE 30

90

92

91

90, Crinometra brevipinna (U.S.N.M.).

91, Crinometra brevipinna var. pulchra: Type specimen from Albatross stations 2319-2350 (U.S.N.M., 25473).

92, Crinomctra brevipinna var. gemmnta: Type specimen from Albatross station 2330 (U.S.N.M., 25474).

U. S, NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 31

97

93, Crinometra hrevipiinia: Specimen shown on plate 30, figure 90 (U.S.X.M.).

94, Crinometra hre?i pinna var. marzaritaera: Specimen from Albatross station 2156, X 2 (U.S.X.M., 16898).
95, 96, Strotometra hepburniana: Specimens from the Korean Strait, X 2 (C.M.).

97, Strntometra priamus: Tj'pe specimen from Siboga station 266, "/.. 2 (Amsterdam Mus.).

U. S. NATIONAL MUSEUM

BULLETIN 82. PART 4C PLATE 32

100

98, Crinomctra brevipinna var. inornata: Type specimen from Albatross station 2154, X 2 (U.S.N.M., 25475).

99, Cnnometra brevipinna var. insculpta: Type specimen from Albatross station 2753 (U.S.N.M., 25477).
100-103, Crotalometra sentifera: 100, 103, Specimen from the Maldive Islands in 914 meters (Cairo, Egypt, Mus.);

101, type specimen from the Laccadive Islands in 1,265 meters (I.M.); 102, distal portion of an arm
from the type specimen (I.M.).
104, Strotometra hepburniana: Specimen from the Korean Strait, X 2 (CM.).

INDEX

acoela, Antedon, 116, 192, 194, 245, 354, 355,

357, 358.
Poecilometra, 115, 116, 245, 265, 355, 357,

359, 360.

Acoela group, 192, 194, 200.
Actinometra, 3, 39, 100, 279, 280, 343.
granulifera, 280, 343.
pulchella, 39, 101, 103, 124.
sp., 101, 103.

aculeata, Antedon, 191, 202, 204, 206, 222.
Charitometra, 204, 206, 348.
Chlorometra, 205, 206.
Chondrometra, 202 (in key) 203, 204, 205,

206.
ncuta, Daidalometra, 23, 25.

Stenometra, 25, 26, 27, 28.
acutiradia, Antedon, 1, 119, 132, 133, 134.

Stiremetra, 120, 121 (in key), 127, 132, 134,

351.

Thalassometra, 132.
acutus, Saracrinus, 245.
Adelometra angustiradia, 98, 99.
adriani, Anthometra, 18, 22, 41, 64, 119, 141,

145, 148, 170, 221, 227, 228.
agassizi, Thalassometra, 158.
agassizii, Antedon, 113, 154, 156, 158, 161, 182,

186, 191, 213, 215, 216, 218.
Myzostoma, 39.

Thalassometra, 109, 113, 121, 138, 152, 154
(in key), 168, 160, 161, 162, 180, 182, 186,
191, 213, 215, 216, 218.
Aglaometra, 4, 6 (in key), 91, 107, 108, 116, 118,

152.

Aglaometra eupedata, 91, 108, 109, 115, 116.
incerta, 103, 107, 108 (in key), 114, 116.
propinqua, 91, 108 (in key), 116, 117, 118,

pi. 15, fig. 47.
sulcata, 91, 108, 109 (in key), IIS, 119,

pi. 13, fig. 40.

valida, 17, 103, 107, 108 (in key), 109, 114,
127, 350, pi. 12, fig. 37, pi. 13, figs. 38, 39.
vera, 91, 108, 116, 118.
ajax, Parametra, 64, 65 (in key), 84, 86, pi. 9,

fig. 29.
alboflava, Antedon, 88, 89.

Lissometra, S8, 89, pi. 11, fig. 34.
Parametra, 88, 89.
Thalassometra, 88, 89.

Alecto serrata, 30, 38.
alternicirrus, Diplocrinus, 39.
Amphimetra discoidea, 27.
andersoni, Antedon, 1, 191, 192.

Pontiometra, 1, 191, 192.
angulata, Ophiothrix, 41
angusta, Crinometra brevipinna var., 284, 287,

288, 291 (in key). 329, 330, 335, 347.
angusticalyx, Antedon, 104, 182, 192, 194, 195,
263, 265, 281, 287, 329, 330, 335, 336,
344, 346, 347.
Charitometra, 263, 265.
Glyptometra, 230 (in key), 263, 357.
Pachylometra, 265, 266.
Perissometra, 196, 263, 265, 287, 333, 337,

338.
angustiradia, Adelometra, 98, 99.

Antedon, 98, 99.
Annacrinus wyville-thomsoni, 39, 104, 106, 121,

124.

annae, Perissometra, 238.
annandalei, Crotalometra, 138, 148, 151.

Oceanometra, 109, 113, 138 (in key), 139,

144, 145, 151, pi. 15, figs. 45, 46.
Thalassometra, 113, 139, 141, 144, 148.
anomala, Cyllometra, 16.

Antedon, 1, 5, 7, 23, 29, 39, 41, 42, 64, 69, 81,
88, 89, 90, 100, 107, 113, 116, 119, 124,
125, 128, 134, 137, 151, 152, 156, 172,
175, 177, 182, 185, 186, 191, 192, 201,
202, 206, 208, 213, 215, 227, 229, 236,
246, 253, 265, 270, 274, 279, 280, 338,
343, 345, 346, 347, 348, 351, 354, 359,
361, 368, 370.
acoela, 116, 192, 194, 245, 354, 355, 357,

358.

aculeata, 191, 202, 204, 206, 222.
acutiradia, 1, 119, 132, 133, 134.
agassizii, 113, 154, 156, 158, 161, 182, 186,

191, 213, 215, 216, 218.
alboflava, 88, 89.
andersoni, 1, 191, 192.
angusticalyx, 104, 182, 192, 194, 195, 263,
265., 281, 287, 329, 330, 335, 336, 344,
346, 347.

angustiradia, 98, 99.
aster, 18, 21, 42, 49, 51, 52.
basicurva, 103, 125, 182, 191, 348, 351.

371

843803—50

372

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Antedon bassett-smithi, 1.
bifida, 350.

bispinosa, 1, 154, 155, 156, 160.
brevicirra, 1.
brevicuneata, 69.

brevipinna, 1, 188, 189, 192, 279, 280, 281,
284, 286, 287, 288, 309, 310, 312, 323,
343, 344, 346, 347.
brevipinna var. concinna, 303, 304.

var. coronata, 282, 284, 310, 320, 347.
var. decora, 281, 286, 291, 292, 302,

347.

var. diadema, 282, 286, 346, 347.
var. elegans, 281, 282, 287, 298, 303,

310, 346, 347.
var. gracilis, 282, 286, 296, 302, 346,

347.
var. granulifera, 316, 317, 319, 320,

321, 331.

var. granulosa, 286, 325, 347.
var. insculpta, 286, 304, 305, 306, 308.
var. laevis, 282, 311, 346, 347.
var. ornata, 282, 320, 323, 347.
var. pourtalesi, 281, 282, 287, 309, 347.
var. pulchella, 303, 304.
var. pulchra, 282, 297, 346, 347.
var. spinosa, 282, 286, 310, 316, 320,

346, 347.
var. tuberosa, 282, 286, 302, 303, 304,

306, 310, 325, 346, 347.
breviradia, 1, 124, 126, 127, 128, 133.
capensis, 192.
carinata, 63, 338.
compressa, 1, 65, 66, 69, 70, 71, 72, 192,

194, 196, 348.

conifera, 7, 13, 17, 18, 21, 22, 51, 56, 57.
denticulata, 1.
diadema, 7, 18, 21.
discoidea, 192, 194.
distincta, 104, 182, 192, 194, 196, 199, 227,

236, 249, 253, 254.
duplex, 1, 60, 186, 188, 191, 192.
echinata, 1, 176, 177.
elegans, 30, 40.
eversa, 126, 128.
field!, 1.
flagellata, 69.

flava, 101, 104, 105, 106, 107.
flavomaculata, 1.
flexilis, 1, 68, 69, 70, 160, 191, 192, 195, 213,

215, 228.
garrettiana, 194, 198, 202, 204, 206, 221,

222, 223, 227.
gracilis, 1, 165, 167, 173. 174, 175, 176.

Antedon granulifera, 104, 180, 182, 192, 243.

249, 280, 281, 286, 287, 31», 319, 320,

325, 326, 329, 338, 343, 344, 345, 346,

347.

hana, 7, 23, 27, 28.
hawaiiensis, 170.

hepburniana, 194, 352, 361, 368, 370.
hirsuta, 175.
inaequalis, 104, 182, 192, 194, 195, 243, 245,

246, 268, 344.

incerta, 1, 90, 91, 103, 108, 114, 115, 116.
incisa, 191, 194, 347, 352, 354.
inequalis, 243.
inopinata, 192.
lata, 272, 274.
latipinna, 1, 171, 172.
longicirra, 1.
lusitanica, 1, 39, 60, 104, 121, 124, 125,

133, 181, 182, 191, 192, 345, 348, 351.
macronema, 1, 192.
magnicirra, 90, 97, 99, 108, 192.
magnicirrus, 97.
magnicrinus, 97.
moorei, 1, 66.
multispina, 1, 101, 103, 104, 125, 160, 180,

181, 182, 183, 192, 345.
n. sp., 358.
omissa, 184, 185.

orion, 18, 21, 64, 65, 72, 82, 194, 196, 348.
parvipinna, 191, 361, 365, 368.
patula, 1, 68, 69, 192, 208, 209, 212, 213,

216, 218, 219.
pergracilis, 173.
phalangium, 125.
porrecta, 1, 100, 101, 103, 104, 105, 106,

181, 182, 192, 345.
pourtalesi, 1, 192, 280, 284, 287, 309, 310,

320, 345, 347.
pourtalesii, 280, 344, 345.
pubescens, 171, 172, 173, 174, 175.
pusilla, 1.
quiuquecostata, 1, 7, 13, 17, 18, 21, 22, 39,

51, 56, 58, 192.
radiospina, 126, 128.
robusta, 1, 69, 160, 192, 208, 213, 218.
savignyi, 268.
scalaris, 359, 360.
sclateri, 192, 268, 269, 270.
setosa, 182, 183.

sp., 30, 101, 182, 183, 263, 265, 355.
spinicirra 1, 133, 136, 137.
spinifera, 1, 17, 29, 30, 39, 40, 192.
spinifera var. brevispina, 31, 34, 40.
tuberosa, 191, 194, 227, 232, 236.
valida, 1, 17, 90, 91, 103, 108, 109, 113, 115.

INDEX

373

Antedon variospina, 126, 129.

vicaria, 1.

villosa, 151, 162, 163.

woodmasoni, 42, 60, 61.
Antedon (Crotalometra), 100.

flava, 105, 107.

lusitanica, 121, 125.

porrecta, 101.
Antedonidae, 1, 22.
Anthometra adriani, 18, 22, 41, 64, 119, 141, 145,

148, 170, 221, 227, 228.

arachnoides, Daidalometra, 23 (in key), 25, 27,
28, 132, pi. 3, fig. 12.

Stenometra, 25.

Stiremetra, 25, 27.
aranea, Perissometra, 72, 73, 75, 78, 82, 196,

197, 206, 208, 232, 236, 272, 274.
Arcturus pawneeanus, 41.
aster, Antedon, 18, 21, 42, 49, 51, 52.

Cosmiornetra, 18, 21, 43 (in key), 49, 52,
53, 56, pi. 6, fig. 21.

Thalassometra, 49, 52.
Asterometra, 2, 5, 145, 213.

niirifica, 61.
Asterometridae, 1.

attenuata, Thalassometra, 153 (in key), 163,
165, 167, 173, 174, 175, pi. 17, figs. 53, 54.

basicurva, Antedon, 103, 125, 182, 191, 348, 351.
Charitometra, 103, 125, 205, 321, 330, 348,

349, 351, 352, 353, 356.
Basicurva group, 1, 5, 121, 125, 181, 188, 190,

191, 200, 345, 357.
bassett-smithi, Antedon, 1.
bengalensis, Heterometra, 243, 276.
bifida, Antedon, 350.
bispinosa, Antedon, 1, 154, 155, 156, 160.

Thalassometra, 152 (in key), 154, 156, 160.
bocki, Diodontometra, 198, 221, 222, 223, 224,

225, 227.

Bonasa umbellata, 2.
brevicirra, Antedon, 1.
brevicuneata, Antedon, 69.
brevipes, Myzostomum, 345.
brevipinna, Antedon, 1, 188, 189, 192, 279, 280,
281, 284, 286, 287, 288, 309, 310, 312,
323, 343, 344, 346, 347.
Charitometra, 280, 345.
Comatula, 194, 279, 280, 312, 343.
Crinometra, 197, 198, 280, 281, 286, 287,
288, 289, 300, 302, 312, 346, 347, pi. 30,
fig. 90, pi. 31, fig. 93.

Crinometra brevipinna var., 288, 290 (in
key), 312, 347.

brevipinna var. angusta, Crinometra, 284, 287,

288, 291 (in key), 329, 330, S3S, 347.
var. brevipinna, Crinometra, 288, 290 (in

key), SIS, 347.
var. concinna, Antedon, 303, 304.

Crinometra, 288, 290 (in key), 298,

347.

var. coronata, Antedon, 284, 310, 320, 347.
Crinometra, 288, 291 (in key), 320,

323, 347.
var. decora, Antedon, 281, 286, 291, 292,

302, 347.

Crinometra, 296, 297, 299.
var. diadema, Antedon, 282, 286, 346, 347.

Crinometra, 288, 290 (in key), 308,

347.
var. elegans, Antedon, 281, 282, 287, 298,

303, 310, 346, 347.
Crinometra, 197.

var. gemmata, Crinometra, 284, 287, 288,
290 (in key), 318, 330, 347, pi. 30, fig. 92.
var. gracilis, Antedon, 282, 286, 296, 302,
346, 347.

Crinometra, 288, 289 (in key), 296,

297, 347.

var. granulifera, Antedon, 316, 317, 319,
320, 321, 331.

Crinometra, 288, 290 (in key), 316,

326, 347.

var. granulosa, Antedon, 286, 325, 347.
Crinometra, 288, 289, 290 (in key),

325, 347.

var. inornata, Crinometra, pi. 32, fig. 98.
var. insculpta, Antedon, 296, 304, 305,
306, 308.

Crinometra, 284, 288, 289 (in key),
891, 296, 297, 298, 299, 316, 333,
347, pi. 32, fig. 99.

var. laevis, Antedon, 282, 311, 346, 347.
Crinometra, 290 (in key), 311, 347.
var. margaritacea, Crinometra, 288, 290

(in key), 307, pi. 31, fig. 94.
var. ornata, Antedon, 282, 320, 323, 347.
Crinometra, 288, 291 (in key), 323,

347.

var. pourtalesi, Antedon, 281, 282, 287,
309, 347.

Crinometra, 288, 290 (in key), 309,

347.
var..pulchella, Antedon, 303, 304.

Crinometra, 288, 289 (in key), 297,

299, 300, 347.

var. pulchra, Antedon, 283, 297, 346, 347.
Crinometra, 287, 288, 289, 291 (in
key), 326, 334, pi- 30, fig. 91.

374

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

brevipinna var. spinosa, Antedon, 282, 286, 310,
316, 320, 346, 347.

Crinometra, 288, 289, 290 (in key),

316, 347.
var. transversa, Crinometra, 288, 290 (in

key), SOI.

var. tuberosa, Antedon, 282, 286, 302, 303,
304, 306, 310, 325, 346, 347.

Crinometra, 288, 290 (in key), 303,

347.

Brevipinna group, 192, 200, 279, 280, 346.
breviradia, Antedon, 1, 124, 126, 127, 128, 133.
Stiremetra, 120 (in key), 124, 126, 127,

129, 132, 351.
Thalassometra, 126.

Calometra, 192, 365.
Calometridae, 192, 194, 247.
Calyptometra, 195, 199, 228, 229, 278.
Calyptometra lateralis, 232, 276, 278.
capensis, Antedon, 192.
carinata, Antedon, 63, 338.

Perissometra, 72, 73, 77, 78, 82, 196, 197

Tropiometra, 63, 82, 192, 338.
carinifera, Stiremetra, 120, 121 (in key), ISO,

132.

Charitometra, 1, 5, 64, 65, 66, 69, 81, 82, 152,
192, 194, 195, 196, 199, 200, 201 (in key), 202,
206, 208, 215, 218, 227, 229, 236, 246, 253,
265, 268, 270, 274, 279, 280, 345, 347, 348,
351, 352, 354, 361, 368.
Charitometra aculeata, 205, 206, 348.

angusticalyx, 263, 265.

basicurva, 103, 125, 205, 321, 330, S4S,
349, 351, 352, 353, 356.

brevipinna, 280, 345.

compressa, 66, 81, 82.

distincta, 243, 246, 248, 249.

flexilis, 214.

garrettiana, 222, 227.

granulifera, 280, 345.

hepburniana, 348, 368, 370.

imbricata, 280.

inaequalis, 243, 246, 268, 270.

incisa, 348 (in key), 352, 353, 354, 356,
357.

lata, 272, 274, 278.

lateralis, 195, 228, 232, 236, 274, 276, 278.

orion, 81, 82.

parvipinna, 365, 368.

patula, 209.

pourtalesi, 280, 345.

robusta, 216.

Charitometra sclateri, 268.

smithi, 243, 246, 249, 250, 253, 254, 263,

265, 280, 281.
tuberosa, 232, 236, 278, 348.
Charitometridae, 1, 4, 5, 64, 77, 78, 82, 101, 191,
192, 194, 196, 197, 198, 199, 200, 201, 202, 208,
224, 228, 236, 265, 268, 270, 279, 288, 348.
Charitometriden, 193.
Charitometrinae, 5, 192, 194, 200, 346.
Chlorometra, 194, 195, 196, 198, 199, 200, 201
(in key), 202, 206, 208, S21, 222, 227, 348.
aculeata, 205, 206.
garrettiana, 204, 206, 222, 224, 225, 227,

pi. 20, fig. 64.

robusta, 195, 202, 204, 206.
rugosa, 202, 206, 207.
Chondrometra, 195, 199, 200, 201, 202, 204, 206,

207, 222.
aculeata, 199, 202 (in key), 203, 204, 205,

206.

robusta, 199, 202, 203, pi. 19, fig. 60.
rugosa, 77, 199, 202 (in key), 206, 207.
Colobometridae, 1, 270.
Comanthus parvicirra, 346.
rotalaria, 346.
solaster, 243, 254.
Comaster distincta, 1.
Comasteridae, 333, 357.
comata, Zygometra, 2, 3, 30, 40.
Comatella maculata, 151.

stelligera, 1, 3.
Comatilia, 1.
Cornatula, 279.

brevipinna, 194, 279, 280, 312, 243.
Comatule, 101.
Comatules, 121.
Comatulida, 1.
Comatulida Oligophreata, 1.
compressa, Antedon, 1, 65, 66, 69, 70, 71, 72,

192, 194, 196, 348.
Charitometra, 66, 81, 82.
Parametra, 64, 65, 66, 69, 70, 72, 82, 152,

pi. 8, fig. 26.

Thalassometra, 66, 69, 72.
concinna, Antedon brevipinna var., 303, 304.
Crinometra, 281, 287, 298, 346, 347.
Crinometra brevipinna var., 288, 290 (in

key), 298, 347.

conifera, Antedon, 7, 13, 17, 18, 21, 22, 51, 56, 57.
Cosmiometra, 13, 17, 18, 42, 43 (in key),
66, 58, pi. 3, figs. 10, 11, pi. 4, fig. 15.
Stenometra, 56.
Conometridae, 20.

INDEX

375

coronata, Antedon brevipinna var., 284, 310,

320, 347.
Crinometra, 282.
Crinometra brevipinna var., 288, 291

(in key), 320, 323, 347.

Cosmiometra, 2, 4, 5 (in key), 6, 7, 17, 22, 29,

41, 42, 47, 52, 58, 59, 61, 64, 152, 185, 186, 191.

Cosmiometra aster, 18, 21, 43 (in key), 49, 52,

53, 56, pi. 6, fig. 21.
conifera, 13, 17, 18, 42, 43 (in key), 56, 58,

pi. 3, figs. 10, 11, pi. 4, fig. 15.
crassicirra, 17, 22, 42, 43 (in key), 56, 58,

60, 61, 134, 136, pi. 10, fig. 33.
dasybrachia, 43 (in key), 47, 49, 52.
delicata, 42, 43 (in key), 45, 48, 72, pi. 3,

fig. 9.

gardineri, 43 (in key), 60, 61, 68.
helene, 49, 52, 54, 56.
iole, 43 (in key), 61, pi. 4, fig. 14.
koehleri, 42, 186, 191.
komachi, 42, 49, 52, 56.
leilae, 42, 43, 45, 46, pi. 5, fig. 17, pi. 6,

fig. 23.
philippinensis, 43 (in key), 49, 52, 56, 60,

61, pi. 5, fig. 16, pi. 6, fig. 22.
woodmasoni, 42, 43 (in key), 56, 60, 63.

Craspedometra, 99, 149, 152, 269.

crassa, Glyptometra, 196, 229 (in key), #37,

243, pi. 21, fig. 68.

Pachylometra, 214, 215, 237, 242, 281, 345.
Perissometra, 237, 243, 268, 274.
crassicirra, Cosmiometra, 17, 22, 42, 43 (in key),

56, 58, 60, 61, 134, 136, pi. 10, fig. 33.
Thalssometra, 42, 58, 59, 136.
Crinometra, 101, 194, 195, 197, 199, 200, 201
(in key), 219, 227, 228, 247, 271, 279,
280, 281, 282, 287, 319, 320, 335, 345,
346, 347, 348.

brevipinna, 197, 198, 280, 281, 286, 287,
288, 289, 300, 302, 312, 346, 347, pi.
30, fig. 90, pi. 31, fig. 93.
brevipinna var. angusta, 284, 287, 288, 291
(in key), 329, 330, 335, 347.
var. brevipinna, 288, 290 (in key), SIS,

347.
var. concinna, 288, 290 (in key), 298,

347.
var. coronata, 288, 291 (in key), 320,

323, 347.

var. decora, 296, 297, 299.
var. diadema, 197, 288, 290 (in key),

308, 347.
var. elegans, 197.

var. gemmata, 284, 287, 288, 290 (in
key), 318, 330, 347, pi. 30, fig. 92.

Crinometra brevipinna var. gracilis, 288, 289

(in key), 296, 297, 347.
var. gran ulif era, 288, 290 (in key), 316,

326, 347.
var. granulosa, 288, 289, 290 (in key),

325, 347.

var. inornata, pi. 32, fig. 98.
var. insculpta, 284, 288, 289 (in key),
291, 296, 297, 298, 299, 316, 333,
347, pi. 32, fig. 99.
var. laevis, 290 (in key), 311, 347.
var. margaritacea, 288, 290 (in key),

307, pi. 31, fig. 94.
var. ornata, 288, 291 (in key), 323,

347.
var. pourtalesi, 288, 290 (in key), 303,

347.
var. pulchella, 288, 289 (in key), 297,

299, 300, 347.
var. pulchra, 287, 288, 289, 291 (in

key), 326, 334, pi- 30, fig. 91.
var. spinosa, 288, 289, 290 (in key),

316, 347.

var. transversa, 288, 290 (in key), 301.
var. tuberosa, 288, 290 (in key), 303,

347.

concinna, 281, 287, 298, 346, 347.
coronata, 282.

gemmata, 281, 318, 326, 346, 347.
gracilis, 282, 298, 347.
granulifera, 197, 282, 326, 327, 347, 334,

335.

imbricata, 282, 326, 327, 331, 332, 347.
insculpta, 197, 281, 291, 296, 302, 335, 342,

346, 347.

margaritacea, 281, 307, 346, 347.
mortenseni, 282.
ornata, 282, 318, 319, 347.
pulchra, 197, 281, 287, 297, 327, 334, 335,

346, 347.

transversa, 197, 282, 301, 302, 303, 347.
cristata, Stenometra, 13, 14, 16, 17, 18, 22.
Crossometra, 101, 195, 196, 198, 199, 228, 229,

232, 248, 254, 266.
distincta, 246, 248, 249, 250, 254.
helius, 248, 254, 259.
investigatoris, 254, 259.
septentrionalis, 246, 248, 249, 254, 259.
Crotalometra, 6 (in key), 89, 90, 91, 92, 96, 97,
99., 100, 101, 104, 107, 108, 109, 114,
116, 137, 141, 152.
annandalei, 138, 148, 151.
eridanella, 90, 91, 93, 95, 97.
eupedata, 89, 90, 91, 109, 111, 113, 114,
138, 144, 148.

376

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Crotalometra flava, 90, 91, 104, 105, 107.
incerta, 91, 108, 114, 116.
infelix, 90, 91, 92, 94, 97.
magnicirra, 2, 90, 91 (in key), 93, 95, 97,

98, 99, 100.

marginalis, 90, 91, 93, 97, 98, 100.
marginata, 93, 97.

porrecta, 90, 91, 101, 102, 104, 107, 181.
propinqua, 91, 108, 109, 113, 116, 118.
rustica, 89, 90, 91 (in key), 92, 95, 97, 98,

99, 108, pi. 11, figs. 35, 36, pi. 18, fig. 53.
sentifera, 90, 91, 92, 94, 96, 98, 99, pi. 32,

figs. 100-103.

sulcata, 108, 116, 118, 119.
valida, 91, 108, 109, 114.
vera, 108, 116, 117, 118.
Cyllometra anomala, 16.
manca, 16.

Daidalometra, 5 (in key), 7, 11, S3, 27, 29, 152.
acuta, 23, 25.
arachnoides, 23 (in key), 25, 27, 28, 132,

pi. 3, fig. 12.

eurymedon, 23 (in key), 24-
hana, 7, 11, 23 (in key), 27, pi. 4, fig. 13.
dasybrachia, Cosmiometra, 43 (in key), 4?, 49,

52.
decora, Antedon brevipinna var., 281, 286, 291,

292, 302, 347.

Crinometra brevipinna var. 296, 297, 299.
Stiremetra, 59, 120, 121 (in key), 134.
delicata, Cosmiometra, 42, 43 (in key), 45, 46,

72, pi. 3, fig. 9.
Thalassometra, 42, 46, 47, 72.
dentata, Stenometra, 7, 8, 11, 18, 22, 23, 27, 29,

pi. 5, fig. 18.
denticulata, Antedon, 1.
diadema, Antedon, 7, 18, 21.

Antedon brevipinna var., 282, 286, 346, 347.
Crinometra brevipinna var., 288, 290 (in

key), 308, 347.
Stenometra, 7, 8 (in key), 11, 13, 15, 16,

17, 18, 21, 58, pi. 2, fig. 5.
Thalassometra, 18.
Dichrometra flagellata, 69.
Diodontometra, 79, 196, 198, 208, 210, 221, 222,

348.

bocki, 198, 221, 222, 223, 224, 225, 227.
diplax, Stenometra, 14, 15, 18.
Diplocrinus alternicirrus, 39.

maclearanus, 39.
discoidea, Amphimetra, 27.
Antedon, 192, 194.

distincta, Antedon, 104, 182, 192, 194, 196, 199.

227, 236, 249, 253, 254, 344.
Charitometra, 243, 246, 248, 249.
Comaster, 1.

Crossometra, 246, 248, 249, 250, 254.
Glyptometra, 229 (in key), 249, 254, pi. 23,

figs. 70-72, pi. 24, fig. 73.
Pachylometra, 198, 249, 250, 253, 254, 263.
dorsata, Stenometra, 13, 17, 18, 22.
duplex, Antedon, 1, 60, 186, 188, 191, 192.

Horaeometra, 42, 60, 185, 186, 189, 191,

pi. 6, fig. 24.
Thalassometra, 186.

echinata, Antedon, 1, 176, 177.

Thalassometra, 153 (in key), 176, 177, 184,

185.

electrae, Thalassometra, 152, 153 (in key), IBS.
elegans, Antedon, 30, 40.

Antedon brevipinna var., 281, 282, 287,
298, 303, 310, 346, 347.

Crinometra brevipinna var., 197.
Endoxocrinus mulleri, 39.

parrae, 39.

eridanella, Crotalometra, 90, 91, 93, 95, 97.
Essenensis group, 20.
Eudiocrinus, 234.
Eulima, 18, 20.
eupedata, Aglaometra, 91, 108, 109, 114, 116.

Crotalometra, 89, 90, 91, 109, 111, 113,

114, 138, 144, 148.
europaea, Neocomatella, 103.
eurymedon, Daidalometra, 23 (in key), 84.
eversa, Antedon, 126, 128.

fieldi, Antedon, 1.
Fimbriata group, 3.

fished, Parametra, 64, 65 (in key), 66, 72, 86,
pi. 9, fig. 28.

Thalassometra, 65, 66, 69, 72, 86, 87.
flagellata, Antedon, 69.

Dichrometra, 69.
flava, Antedon, 101, 104, 105, 106, 107.

Antedon (Crotalometra), 105, 107.

Crotalometra, 90, 91, 104, 107.

Koehlermetra, 91, 101 (in key), 105.

Thalassometra, 105, 107.
flavomaculata, Antedon, 1.
flexilis, Antedon, 1, 68, 69, 70, 160, 191, 192,
195, 213, 215, 228.

Charitometra, 214.

Monachometra, 208, 209 (in key), SIS.

Pachylometra, 214, 215.

Perissometra, 68, 69, 70, 160, 196, 214, 215,
232, 274.

INDEX

377

fluctuans, Zygometra, 2, 3.
fragilis, Monachometra, 73, 79, 208, 209 (in
key), 219, 221, 368, p. 20, figs. 62, 63.
Pachylometra, 195, 208, 219, 221.

gardineri, Cosmiometra, 43 (in key), 60, 61, 63.
garrettiana, Antedon, 194, 198, 202, 204, 206,

221, 222, 223, 227.
Charitometra, 222, 227.
Chlorometra, 204, 206, 222, 224, 225, 227,

pi. 20, fig. 64.

gemmata, Crinometra, 281, 318, 326,346, 347.

Crinometra brevipinna var., 284, 287, 288,

290 (in key), SI 8, 330, 347, pi. 30, fig. 92.

gigantea, Oceanometra, 138 (in key), 139,

141, 142, 144, 146, pi. 14, fig. 41.
Thalassometra, 137, 138, 139, 141, 144.
Gisl6nometra perplexa, 270.
glacialis, Heliomctra, 103.
Glenotremites, 20.

Glyptometra, 194, 195, 196, 199, 200, 201 (in
key), 208, 213, 227, 228, 229, 236, 274, 278,
279, 288, 348.
Glyptometra angusticalyx, 230 (in key), 263,

271, 357.
crassa, 196, 229 (in key), 237, 243, pi. 21,

fig. 68.
distincta, 229 (in key), 249, 254, pi. 23,

figs. 70-72, pi. 24, fig. 73.
gorgonia, 242.
hector, 239.

inaequalis, 198, 229 (in key), 243.
incerta, 357.
invenusta, 230 (in key), S7B, 278, pi. 29,

fig. 89.

investigatoris, 230 (in key), 251, 254,

256, pi. 24, figs. 74, 75, pi. 25, figs. 70-78.

lata, 76, 196, 230 (in key), 272, 274, pi.

28, figs. 84-86, pi. 29, fig. 88.
lateralis, 230 (in key), 276, 278, 364, pi.

29, fig. 87.

levigata, 230 (in key), 271, pi. 27, figs. 82,

83.
macilenta, 230 (in key), 259, 275, pi. 26,

figs. 79-81.
patula, 196.

sclateri, 230 (in key), 268.
septentrionalis, 229 (in key), 246, 257, 269.
sp., 278.

sparksi, 230 (in key), 266.
timorensis, 229 (in key), 230, 232, 272,

274, 276, 278, pi. 21, figs. 66, 67.
tuberosa, 77, 195, 198, 203, 205, 229 (in

key), 232, 236, 288, 356, 357, 366, 367,

pi. 22, fig. 69.

Glytometra, 228.

gorgonia, Glyptometra, 242.

Perissometra, 241, 242, 243.
gracilis, Antedon, 1, 165, 167, 173, 174, 175, 176.
Antedon brevipinna var., 282, 286, 296,

302, 346, 347.
Crinometra, 282, 298, 347.
Crinometra brevipinna var., 288, 289 (in

key), 296, 297, 347.
Solanocrinus, 173, 176.
Thalassometra, 153 (in key), 163, 165, 167,

173, 181, 185.

granulata, Parametra, 64, 65 (in key), 66,
67, 68, 69, 72, 82, pi. 7, fig. 25, pi. 10, figs.
31, 32.
gramilifera, Actinometra, 280, 343.

Antedon, 104, 180, 182, 192, 243, 240,
280, 281, 286, 287, 318, 319, 320, 325,
326, 329, 338, 343, 344, 345, 346, 347.
Antedon brevipinna var., 316, 317, 319,

320, 321, 331.
Charitometra, 280, 345.
Crinometra, 197, 282, 326, 327, 347, 334,

335.
Crinometra brevipinna var., 288, 290 (in

key), 316, 326, 347.

Granulifera group, 1, 5, 99, 101, 104, 105, 106,
107, 125, 180, 181, 182, 183, 192, 200, 243,
249, 268, 270, 279, 280, 287, 344, 346, 347.
granulosa, Antedon brevipinna var., 286, 325,

347.
Crinometra brevipinna var. 288, 289, 290

(in key), 325, 347.
group, Acoela, 192, 194, 200.
Essenensis, 20.
Fimbriata, 3.

Granulifera, 1, 5, 99, 101, 104, 105, 106,
107, 125, 180, 181, 182, 183, 192, 200,
243, 249, 268, 270, 279, 280, 287, 344,
346, 347.
Milberti, 192.
Palmata, 69.
Paradoxus, 20.

Savignyi, 99, 192, 200, 268, 269, 270.
Spinifera, 1, 5, 13, 30, 36, 39, 58, 60, 66,
69, 121, 125, 186, 188, 190, 191, 192,
200, 209, 213, 214, 215, 216, 279, 280,
287, 309, 344, 345, 347.

hana, Antedon, 7, 23, 27, 28.

Daidalometra, 7, 11, 23 (in key), 27, pi. 4,

fig. 13.

Stenometra, 26, 27.
Thalassometra, 27, 28.

378

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

hawaiiensis, Antedon, 170.

Thalassometra, 153 (in key), 169, 170.
hector, Glyptometra, 239.
helene, Cosmiometra, 49, 52, 54, 56.
Heliometra glacialis, 103.
Heliometrinae, 22, 193.
helius, Crossometra, 248, 254, 259.

Pachylometra, 246, 248, 254, 257, 259.
hepburniana, Antedon, 194, 252, 361, 368, 370.

Charitometra, 348, 368, 370.

Strotometra, 352, 362 (in key), 365, 366,
367, S68, pi. 31, figs. 95, 96, pi. 32, fig.
104.
Heterometra, 99, 149, 152, 269.

bengalensis, 243, 276.
Himerometra robustipinna, 192.
Himerometridae, 1, 82, 192, 270, 354, 359, 360,

368, 370.
hirsuta, Antedon, 175.

Thalassometra, 153 (in key), 163, 165, 167,

168, 169, 173, pi. 18, fig. 59.
Holocrinus, 263.
Holopus, 193, 279.
Horaeometra, 4, 5, 6 (in key), 152, 185, 186.

duplex, 42, 60, 185, 186, 189, 191, pi. 6,

fig. 24.

Hyocrinus, 174.
Hyponome sarsii, 124.

imbricata, Charitometra, 280.

Crinometra, 282, 326, 327, 331, 332, 347.

Pachylometra, 281, 345.
inaequalis, Antedon, 104, 182, 192, 194, 195,

243, 245, 246, 268, 344.

Charitometra, 243, 246, 268, 270.

Glyptometra, 229 (in key), 24S.

Pachylometra. 198, 243, 246, 263.

Perissometra, 333, 337, 338.
incerta, Aglaometra, 103, 107, 108 (in key),
114, 116.

Antedon, 1, 90, 91, 103, 108, 114, 115, 116.

Crotalometra, 91, 108, 114, 116.

Glyptometra, 357.

Thalassometra, 114.
incisa, Antedon, 191, 194, 347, 352, 354.

Charitometra, 348 (in key), 352, 353, 354,

356, 357.

indica protectus, Stephanometra, 1.
inequalis, Antedon, 243.
infelix, Crotalometra, 90, 91, 92, 94, 97.

Thalassometra, 91, 92, 97.
inopinata, Antedon, 192.

inornata, Crinometra brevipinna var., pi. 32,
fig. 98.

insculpta, Antedon brevipinna var., 286, 304,

305, 306, 308.
Crinometra, 197, 281, 291, 296, 302, 335,

342, 346, 347.

Crinometra brevipinna var., 284, 288, 289
(in key), 891, 296, 297, 298, 299, 316.
333, 347, pi. 32, fig. 99.
invenusta, Glyptometra, 230 (in key), 275,

278, pi. 29, fig. 89.
Pachylometra, 259, 275.
Perissometra, 275, 276.
investigatoris, Crossometra, 254, 259.

Glyptometra, 230 (in key), 251, 254, 256,

pi. 24, figs. 74, 75, pi. 25, figs. 76-78.
Pachylometra, 227, 228, 249, 254, 256, 259.
iole, Cosmiometra, 43 (in key), 61, pi. 4, fig. 14.

koehleri, Cosmiometra, 186, 191.
Koehlermetra, 4, 6 (in key), 90, 91, 100, 101,

152.
Koehlermetra flava, 91, 101 (in key), 105.

porrecta, 91, 101, ISO, 345.
komachi, Cosmiometra, 42, 49, 52, 56.

Thalassometra, 41, 42, 49, 52.

laevigata, Pachylometra, 271, 272.
laevis, Antedon brevipinna var., 282, 311, 346,
347.

Crinometra brevipinna var., 290 (in key),

Sll, 347.
Lamprometra palmata, 69.

palmata palmata, 1.
lata, Antedon, 272, 274.

Charitometra, 272, 274, 278.
Glyptometra, 76, 196, 230 (in key), S72,

274, pi. 28, figs. 84-86, pi. 29, fig. 88.
Perissometra, 195, 196, 230, 232, 272, 274.
lateralis, Calyptometra, 232, 276, 278.

Charitometra, 195, 228, 232, 236, 274,

276, 278.
Glyptometra, 230 (in key), 276, 278, 364,

pi. 29, fig. 87.
Pachylometra, 227, 274.
latipinna, Antedon, 1, 171, 172.

Thalassometra, 153 (in key), 171, 172, 185.
leilae, Cosmiometra, 42, 43, 45, 46, pi. 5, fig.

17, pi. 6, fig. 23.
Leilametra, 4, 6 (in key), 148, 149, 152.

necopinata, 148, 149, pi. 16, figs. 48, 49.
Leptometra, 226.
levigata, Glyptometra, 230 (in key), S71, pi. 27,

figs. 82, 83.

Pachylometra, 198, 263, 265, 271.
lisa, Parametra, 64, 65 (in key), 83.

INDEX

379

Lissometra, 4, 6 (in key), 42, 88, 152.

alboflava, 58, 89, pi. 11, fig. 34.
longicirra, Antedon, 1.
Lophohelia, 303.

luna, Pachylometra, 254, 256, 259.
lusitanica, Antedon, 1, 39, 60, 104, 121, 124, 125,

133, 181, 182, 191, 192, 345, 348, 351.
Antedon (Crotalometra), 121, 125.
Stiremetra, 39, 60, 101, 104, 120 (in key),
Igl, 122, 125, 126, 127, 180, 181, 186,
191, 345, 348, 351.
Thalassometra, 121, 125.

raacilenta, Glyptometra, 230 (in key), 259, 275,
pi. 26, figs. 79-81.

Pachylometra, 216, 219, 259, 263.

Perissometra, 246, 254, 260, 262.
maclearanus, Diplocrinus, 39.
macronema, Antedon, 1, 192.
maculata, Comatella, 151.

magna, Oceanometra, 138 (in key), 139, 141,
148, 148, pi. 14, figs. 42, 43.

Thalassometra, 138, 139, 141, 142, 144, 148.
magnicirra, Antedon, 90, 97, 99, 108, 192.

Crotalometra, 2, 90, 91 (in key), 93, 95, 97,
98, 99, 100.

Thalassometra, 91, 97, 99, 100.
magnicirrus, Antedon, 97.
magnicrinus, Antedon, 97.
magnificus, Moiraster, 302.
manca, Cyllometra, 16.
margaritacea, Crinometra, 281, 307, 346, 347.

Crinometra brevipinna var., 288, 290 (in

key), 307, pi. 31, fig. 94.
margaritifera, Thalassometra, 153 (in key), 165,

168, pi. 17, fig. 55.
marginalia, Crotalometra, 90, 91, 93, 97, 98, 100.

Thalassometra, 92, 95, 97, 100.
marginata, Crotalometra, 93, 97.

Thalassometra, 153 (in key), 168, 169.
Mariametra, 279.

vicaria, 1.
Mariametridae, 84.
Melanella, 20.

sp., 13.

microdiscus, Zygometra, 124.
Milberti group, 192.

Millericrinus recubariensis, 176, 177, 191.
mirifica, Asterometra, 61.
Moiraster magnificus, 302.
Molpadiidae, 265.
Monachomera, 208.

Monachometra, 79, 195, 196, 199, 201 (in key),
SOS, 210, 213, 219, 221.

flexilis, 208, 209 (in key), SIS.

Monachometra fragilis, 73, 79, 208, 209 (in
key), 219, 221, 368, pi. 20, figs. 62, 63.
mortenseni, 73, 78, 79, 82, 196, 197, 208,

221.

patula, 208 (in key), 209, pi. 20, fig. 61.
robusta, 196, 208, 209 (in key), 216.
moorei, Antedon, 1, 66.
mortenseni, Crinometra, 282.

Monachometra, 73, 78, 79, 82, 196, 197,

208, 221.

mulleri, Endoxocrinus, 39.
multispina, Antedon, 1, 101, 103, 104, 125, 160,

180,181,182,183,192,345.
Thalassometra, 102, 103, 125, 154 (in key),

160, 179, 180, 181, 182, 183, 345.
Myzostoma agassizii, 39.
Myzostomum brevipes, 345.
pictum, 39.

Nanometra, 192.

necopinata, Leilametra, 148, 149, pi. 16, figs.

48, 49.

Neocomatella europaea, 103.
pulchella, 39, 124.

occidentalis, Perissometra, 237, 243, 260, 261,

262, 263, 268.
Oceanometra, 4, 6 (in key), 137, 138, 141, 148,

152.
annandalei, 109, 113, 138 (in key), 144,

145, 148, 151, pi. 15, figs. 45, 46.
gigantea, 138 (in key), 139, 141, 142, 144,

146, pi. 14, fig. 41.

magna, 138 (in key), 139, 141, 148, 144,

148, pi. 14, figs. 42, 43.
Oligophreata, 1, 2, 193.
omissa, Antedon, 184, 185.

Thalassometra, 154 (in key), 184, 185.
Ophiothrix angulata, 41.
orion, Antedon, 18, 21, 64, 65, 72, 82, 194, 196,

348.

Charitometra, 81, 82.

Parametra, 18, 21, 64, 65 (in key), 7S, 78,
80, 82, 152, 196, 197, 208, 221, 232, 274,
pi. 5, figs. 19, 20, pi. 8, fig. 27, pi. 10,
fig. 30.

Thalassometra, 72.
ornata, Antedon brevipinna var., 282, 320, 323,

347.

Qrinometra, 282, 318, 319, 347.
Crinometra brevipinna var., 288, 291 (in

key), 323, 347.

ornatissimns, Strotometra, 362.
ornatissimus, Strotometra, 361 (in key), S62,
pi. 20, fig. 65.

380

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

Pachyantedon, 176.

Pachylometra, 101, 158, 192, 194, 195, 196,
197, 199, 200, 208, 213, 215, 219, 227,
228, 229, 246, 248, 253, 254, 270, 272,
279, 346, 348.
angusticalyx, 265, 266.
crassa, 214, 215, 281, 237, 242, 345.
distincta, 198, 249, 250, 253, 254, 263.
flexilis, 214, 215.
fragilis, 195, 208, 219, 221.
helius, 246, 248, 254, 257, 259.
imbricata, 281, 345.
inaequalis, 198, 243, 246, 263.
invenusta, 259, 275.

investigatoris, 227, 228, 249, 254, 256, 259.
laevigata, 271, 272.
lateralis, 227, 274.
levigata, 198, 263, 265, 271.
luna, 254, 256, 259.
macilenta, 216, 219, 259, 263.
n. sp. 266, 268.
patula, 209. 213.
robusta, 216, 219, 260, 261.
sclateri, 193, 268, 270.
selene, 249, 253, 254.
septentrionalis, 195, 246, 248, 249.
smithi, 249, 253.
palmata, Lamprometra, 69.
Palraata group, 69.
palmata palmata, Lamprometra, 1.
Paradoxus group, 20.
Parametra, 4, 5, 6 (in key), 42, 64, 65, 69, 72,

78, 82, 87, 88, 152, 194, 196, 200, 348.
ajax, 64, 65 (in key), 84, 86, pi. 9, fig. 29.
alboflava, 88, 89.
compressa, 64, 65, 66, 69, 70, 72, 82, 152,

pi. 8, fig. 26.
fisheri, 64, 65 (in key), 66, 72, 86, pi. 9,

fig. 28.
granulata, 64, 65 (in key), 66, 67, 68, 69,

72, 82, pi. 7, fig. 25, pi. 10, figs. 31, 32.
lisa, 64, 65 (in key), 8S.
orion, 18, 21, 64, 65 (in key), 72, 77, 78,
80, 82, 152, 196, 197, 208, 221, 232, 274,
pi. 5, figs. 19, 20, pi. 8, fig. 27, pi. 10,
fig. 30.

parrae, Endoxocrinus, 39.
parvicirra, Comanthus, 346.
parvipinna, Antedon, 191, 361, 365, 368.
Charitometra, 365, 368.
Strotometra, 196, 361 (in key), 365, 368,

370.
patula, Antedon, 1, 68, 69, 192, 208, 209, 212,

213, 216, 218, 219.
Charitometra, 209.

patula, Glyptometra, 196.

Monachometra, 208 (in key), 209, pi. 20,

fig. 61.

Pachylometra, 209, 213.
Perissometra, 68, 69, 195, 196, 209, 213,

232, 274.

pawneeanus, Arcturus, 41.
Pentacrinus wyville-thomsoni, 121, 124.
pergracilis, Antedon, 173.

Thalassornetra, 163, 173, 175, 176, 185.
peripolos, Thalassometra, 154 (in key), 178,

180, pi. 18, figs. 56, 57.

Perissometra, 158, 195, 196, 199, 208, 213, 215,
219, 228, 229, 232, 242, 243, 254, 262, 265,
266, 274, 275.
Perissometra angusticalyx, 196, 263, 265, 287,

333, 337, 338.
annae, 238.
aranea, 72, 73, 75, 78, 82, 196, 197, 206,

208, 232, 236, 272, 274.
carinata, 72, 73, 77, 78, 82, 196, 197.
crassa, 237, 243, 268, 274.
flexilis, 68, 69, 70, 160, 196, 214, 215, 232,

274.

gorgonia, 241, 242, 243.
inaequalis, 333, 337, 338.
invenusta, 275, 276.
lata, 195, 196, 230, 232, 272, 274.
macilenta, 246, 254, 260, 262.
occidentalis, 237, 243, 260, 261, 262, 263,

268.

patula, 68, 69, 195, 196, 209, 213, 232, 274.
robusta, 69, 160, 209, 216.
selene, 249, 251, 254.
sparksi, 266, 268.
timorensis, 196, 230, 232, 272, 274, 276.

Perometrinae, 1.

perplexa, Gisldnometra, 270.

Stiremetra, 120, 121 (in key), 129, pi. 14,

fig. 44.

Thalassometra, 129, 173, 175.
phalangium, Antedon, 125.
philippinensis, Cosmiometra, 43 (in key), 49,

6S, 56, 60, 61, pi. 5, fig. 16, pi. 6, fig. 22.
pictum, Myzostomum, 39.
Poecilometra, 1, 5, 192, 194, 195, 196, 201 (in

key), 199, 200, 348, 354, 355, 359, 360.
Poecilometra acoela, 115, 116, 245, 265, 355,
357, 359, 360.

scalaris, 355 (in key), 358, 359, 360.
Pontiometra andersoni, 1, 191, 192.
porrecta, Antedon, 1, 100, 101, 103, 104, 105,

106, 181, 182, 192, 345.
Antedon (Crotalometra) , 101.

INDEX

381

porrecta, Crotalometra, 90, 91, 101, 102, 104,

107, 181.

Koehlermetra, 91, 101, 180, 345.
Thalassometra, 101, 104.
propinqua, Crotalometra, 91, 108, 109, 113, 116,

118.

pourtalesi, Antedon, 1, 192, 280, 284, 287, 309,
310, 320, 345, 347.

Antedon brevipinna var., 281, 282, 287,

309, 347.

Charitometra, 280, 345.
Crinometra brevipinna var., 288, 290 (in

key), 309, 347.

pourtalesii, Antedon, 280, 344, 345.
priamus, Strotometra, 361 (in key), 363, 365,

pi. 31, fig. 97.
Promachocrinus, 2.
propinqua, Aglaoruetra, 91, 108 (in key), 116,

117, 118, pi. 15, fig. 47.
protectus, Stephanometra indica, 1.
Psathyrometra, 115.
Pterometra, 2, 5.
Ptilometra, 2, 3, 5.

splendida, 263, 265.
Ptilometridae, 1, 192.
Ptilometrinae, 5.

pubescens, Antedon, 171, 172, 173, 174, 175.
Thalassometra, 165, 167, 173, 175, 176.
pulchella, Actinometra, 39, 101, 103, 124.
Antedon brevipinna var., 303, 304.
Crinometra brevipinna var., 288, 289 (in

key), S97, 299, 300, 347.
Neocomatella, 39, 124.
pulchra, Antedon brevipinna var., 282, 297,

346, 347.
Crinometra, 197, 281, 287, 297, 327, 334,

335, 346, 347.
Crinometra brevipinna var., 287, 288,

291 (in key), 326, 334, pi- 30, fig. 91.
pusilla, Antedon, 1.

quinquecostata, Antedon, 1, 7, 13, 17, 18, 21,

22, 39, 51, 56, 58, 192.
Stenometra, 7, 8 (in key), IS, 16, 17, 18, 21,

30, 39, 58, pi. 1, figs. 2, 3, pi. 2, figs. 4,

6,7.
Thalassometra, 13, 18, 21, 22.

radiospina, Antedon, 126, 128.
recubariensis, Millericrinus, 176, 177, 191.
robusta, Antedon, 1, 69, 160, 192, 208, 213, 218.

Charitometra, 216.

Chlorometra, 202, 204, 206.

Chondrometra, 199, 202, 203, pi. 19, fig. 60.

robusta, Monachometra, 196, 208, 209 (in key),

216.

Pachylometra, 216, 219, 260, 261.
Perissometra, 69, 160, 209, 216.
robustipinna, Himerometra, 192.
rodstomi, Scalpellum, 41.
rotalaria, Comanthus, 346.
rugosa, Chlorometra, 202, 206, 207.

Chondrometra, 77, 199, 202 (in key), 206,

207.

rugosus, Uroptychus, 41.

rustica, Crotalometra, 89, 90, 91 (in key), 92,
95, 97, 98, 99, 108, pi. 11, figs. 35/36, pi.
18, fig. 53.
Thalassometra, 91, 92, 97.

Saracrinus acutus, 245.

sarsii, Hyponome, 124.

savignyi, Antedon, 268.

Savignyi group, 99, 192, 200, 268, 269, 270.

scalaris, Antedon, 359, 360.

Poecilometra, 355 (in key), 358, 359, 360.
Scalpellum, 41.

rodstomi, 41.
sclateri, Antedon, 192, 268, 269, 270.

Charitometra, 268.

Glyptometra, 230 (in key), 268.

Pachylometra, 193, 268, 270.
selene, Pachylometra, 249, 253, 254.

Perissometra, 249, 251, 254.
sentifera, Crotalometra, 90, 91, 92, 94, 96, 98,
99, pi. 32, figs. 100-103.

Thalassometra, 91, 92.

septentrionalis, Crossometra, 246, 248, 249, 254,
259.

Glyptometra, 229 (in key), 346, 257, 269.

Pachylometra, 195, 246, 248, 249.
serrata, Alecto, 30, 38.
setosa, Antedon, 182, 183.

Thalassometra, 154 (in key), 180, 181, 182,

183.

smithi. Charitometra, 243, 246, 249, 250, 253,
254, 263, 265, 280, 281.

Pachylometra, 249, 253.

snelliusi, Stenometra, 7, 8, IS, 22, pi. 1, fig. 1.
Solanocrinus graeilis, 173, 176.
solaster, Comanthus, 243, 254.
sparksi, Glyptometra, 230 (in key), 266.

Perissometra, 266, 268.
spicata, Stephanometra, 18.
spinicirra, Antedon, 133, 136, 137.

Stiremetra, 120, 121 (in key), 127, 132,
133, 136.

Thalassometra, 136.

382

BULLETIN 82, UNITED STATES NATIONAL MUSEUM

spinifera, Antedon, 1, 17, 29, 30, 39, 40, 192.
Stylometra, 17, 29, SO, 39, 40, 41, 42, 120,

188, pi. 3, fig. 8.
Thalassometra, 30, 40.

spinifera var. brevispina, Antedon, 31, 34, 40.
Spinifera group, 1, 5, 13, 30, 36, 39, 58, 60, 66,
69, 121, 125, 186, 188, 190, 191, 192, 200, 209,
213, 214, 215, 216, 279, 280, 287, 309, 344, 345,
346, 347.
spinosa, Antedon brevipinna var., 282, 286, 310,

316, 320, 346, 347.
Crinometra brevipinna var., 288, 289, 290

(in key), 316, 347.
splendida, Ptilometra, 263, 265.
stelligera, Comatella, 1, 3.
Stenometra, 4, 5 (in key), 7, 11, 16, 17, 18, 21,

23, 28, 41, 58, 152, 155.
acuta, 25, 26, 27, 28.
arachnoides, 25.
conifera, 56.

cristata, 13, 14, 16, 17, 18, 22.
dentata, 7, 8, 11, 18, 22, 23, 27, 29, pi. 5,

fig. 18.
diadema, 7, 8 (in key), 11, 13, 15, 16, 17,

IS, 21, 51, 58, pi. 2, fig. 5.
diplax, 14, 15, 18.
dorsata, 13, 17, 18, 22.
hana, 26, 27.

quinquecostata, 7, 8 (in key), IS, 16, 17,
18, 21, 30, 39, 58, pi. 1, figs. 2, 3, pi. 2,
figs. 4, 6, 7.

snelliusi, 7, 8 (in key), IS, 22, pi. 1, fig. 1.
Stephanometra indica protectus, 1.

spicata, 18.
Stiremetra, 4, 5, 6 (in key), 23, 108, US, 120,

128, 129, 132, 137, 152.
acutiradia, 120, '21 (in key), 127, 1S2, 134,

351.

arachnoides, 25, 27.
breviradia, 120 (in key), 124, 126, 127, 129,

132, 351.

carinifera, 120, 121 (in key), ISO, 132.
decora, 59, 120, 121 (in key), 134.
lusitanica, 39, 60, 101, 104, 120 (in key),
121, 122, 125, 126, 127, 180, 181, 186,
191, 345, 348, 351.
perplexa, 120, 121 (in key), 129, pi. 14, fig.

44.
spinicirra, 120, 121 (in key), 127, 132, 133,

136.
Strotometra, 194, 195, 198, 199, 200, 201 (in

key), 348, 361, 368.

hepburniana, 352, 362 (in key), 365, 366,
367, 365, pi. 31, figs. 95, 96, pi. 32, fig.
104.

Strotometra ornatissimns, 362.

ornatissimus, 361 (in key), 362, pi. 20, fig.

65.

parvipinna, 196, 361 (in key), 365, 368, 370.
priamus, 361 (in key), 363, 365, pi. 31, fig.

97.

Stylometra, 1, 4, 5 (in key), 29, 40, 41, 42, 152.
sp., 30.
spinifera, 17, 29, SO, 39, 40, 41, 42, 120,

188, pi. 3, fig. 8.
sulcata, Aglaometra, 91, 108, 109 (in key), 118,

119, pi. 13, fig. 40.
Crotalometra, 108, 116, 118, 119.

Thalassometra, 1, 2, 4, 5, 6 (in key), 7, 17, 21,
23, 28, 29, 40, 41, 42, 52, 61, 64, 65, 66,
69, 72, 81, 82, 88, 89, 90, 91, 97, 100, 101,
105, 107, 108, 113, 114, 115, 116, 119,
125, 126, 128, 134, 137, 138, 141, 144,
149, 151, 152, 156, 161, 162, 163, 165,
170, 172, 175, 176, 182, 183, 185, 186,
191, 192.

acutiradia, 132.

agassizi, 158.

agassizii, 109, 113, 121, 138, 152, 154, (in
key), 158, 160, 161, 162, 180, 182, 186,
191, 213, 215, 216, 218.

alboflava, 88, 89.

annandalei, 113, 139, 141, 144, 148.

aster, 49, 52.

attenuata, 153 (in key), 163, 165, 167, 173,
174, 175, pi. 17, figs. 53, 54.

bispinosa, 152, (in key), 154, 156, 160.

breviradia, 126.

compressa, 66, 69, 72.

crassicirra, 42, 58, 59, 136.

delicata, 42, 46, 47, 72.

diadema, 18.

duplex, 186.

echinata, 153 (in key), 176, 177, 184,185.

electrae, 152, 153 (in key), 156.

fisheri, 65, 66, 69, 72, 86, 87.

flava, 105, 107.

gigantea, 137, 138, 139, 141, 144.

gracilis, 153 (in key), 163, 165, 173, 181,
185.

hana, 27, 28.

hawaiiensis, 40, 153 (in key), 169. 170.

hirsuta, 153 (in key), 163, 165, 167, 168,
169, 173, pi. 18, fig. 59.

incerta, 114.

infelix, 91, 92, 97.

komachi, 41, 42, 49, 52.

latipinna, 153 (in key), 171, 172, 185.

lusitanica, 121, 125.

INDEX

383

Thalassometra magna, 138, 139, 141, 142, 144,

148.

magnicirra, 91, 97, 99, 100.
margaritifera, 153 (in key), 165, 168, pi. 17,

fig. 55.

marginalis, 92, 95, 97, 100.
marginata, 153 (in key), 168, 169.
multispina, 102, 103, 125, 154 (in key), 160,

179, 180, 181, 182, 183, 345.
omissa, 154 (in key), 184, 185.
orion, 72.

pergracilis, 163, 173, 175, 176, 185.
peripolos, 154 (in key), 178, 180, pi. 18,

figs. 56, 57.

perplexa, 129, 173, 175.
porrecta, 101, 104.
pubescens, 165, 167, 173, 175, 176.
quinquecostata, 13, 18, 21, 22.
rustica, 91, 92, 97.
sentifera, 91, 92.

setosa, 154 (in key), 180, 181, 182, 183.
sp., 156, 158, 185.
spinicirra, 136.
spinifera, 30, 40.
valida, 109.
villosa, 152, 154 (in key), IBS, 163, pi. 17,

figs. 50-52.
woodmasoni, 60.
Thalassometres, 3.

Thalassometridae, 1, 3, 4, 5, 7, 23, 27, 29, 42,
64, 65, 77, 78, 82, 84, 88, 90, 97, 98, 99, 100,
101, 104, 105, 107, 108, 109, 113, 114, 116, 119,
121, 125, 134, 137, 141, 148, 151, 152, 156, 163,
171, 172, 175, 177, 182, 186, 191, 192, 194, 196,
197, 200, 236, 270, 345, 347, 348, 354, 359, 360,
368, 370.
Thalassometrinae, 3, 5, 40, 91, 101, 108, 180,

186.

Thalassometriden, 3.
Thaumatocrinus, 101.
Thaumatometra, 158.
timorensis, Glyptometra, 229 (in key), 230, 232,

272, 274, 276, 278, pi. 21, figs. 66, 67.
Perissoinetra, 196, 230, 232, 272, 274, 276.

transversa, Crinometra, 197, 282, 301, 302, 303,

347.
Crinometra brevipinna var., 288, 290 (in

key), SO/.

Tropiometra carinata, 63, 82, 192, 338.
Tropiometrida, 1, 3, 193.
Tropiometridae, 2, 3, 5.
tuberosa, Antedon, 191, 194, 227, 232, 236.

Antedon brevipinna var., 282, 286, 302,

303, 304, 306, 310, 325, 346, 347.
Charitometra, 232, 236, 278, 348.
Crinometra brevipinua var., 288, 290 (in

key), SOS, 347.

Glyptometra, 77, 195, 198, 203, 205, 229
(in key), 2S2, 236, 288, 356, 357, 366, 367,
pi. 22, fig. 69.

umbellata, Bonasa, 2.
Uroptychus rugosus, 41.

valida, Aglaometra, 17, 103, 107, 108 (in key),
109, 114, 127, 350, pi. 12, fig. 37, pi. 13,
figs. 38, 39.
Antedon, 1, 17, 90, 91, 103, 108, 109, 113,

115.

Crotalometra, 91, 108, 109, 114.
Thalassometra, 109.
variospina, Antedon, 126, 129.
vera, Aglaometra, 91, 108, 116, 118.

Crotalometra, 108, 116, 117, 118.
vicaria, Antedon, 1.
Mariametra, 1.
villosa, Antedon, 151, 162, 163.

Thalassometra, 152, 154 (in key), 162, 163,
pi. 17, figs. 50-52.

woodmasoni, Antedon, 42, 60, 61.

Cosmiometra, 42, 43 (in key), 56, 60, 63.

Thalassometra, 60.

wyville-thomsoni, Annacrinus, 39, 104, 106, 121,
124.

Pentacrinus, 121, 124.

Zygometra comata, 2, 3, 30, 40.
fluctuans, 2, 3.
microdiscus, 124.

NEW NAMES

New genus. — Koehler metro, , p. 100.

New species. — Daidalometra eurymedon, p. 24 ;• Cosmiometra iole, p. 61; Parametra
lisa, p. 83; Stiremetra decora, p. 134.

New varieties. — Crinometra brevipinna var. pulchella, p. 297; Crinometra brevipinna
var. angusta, p. 335.

New names. — Glyptometra annae, p. 238; Glyptometra hector, p. 239.