78 THE ECHINODERMS OF TORRES STRAIT. 
List and present status of Sea-stars which have been referred to Ophidiaster—continued. 
tuberculatus Miiller and Troschel, 1842 =Nardoa tuberculata. 
tuberifer Sladen, 1889 = Tamaria tuberifera. 
tumescens Koehler, 1910 = Tamaria tumescens. 
trychnus Fisher, 1913 =O. granifer. 
vestitus Perrier, 1869, is an Echinaster. 
In addition to the 18 valid Ophidiasters listed above, a nineteenth species (lioderma) 
is included in the following key and is fully described and figured on page 80. 
Key to the Species of Ophidiaster. 
A. No granules occur between furrow spinelets on inner surface of furrow; madreporite single. 
B. No spinelets or conspicuous spiniform granules on marginal or abactinal plates of distal part 
of ray. 
C. No pedicellariz present. 
D. R=6-10 br. 
E. Rays cylindrical; no isolated papule between actinolateral plates. 
F. Adambulacral spines very stout, furrow pair markedly thickened at tip, and 
subambulacral often nearly as thick as long...............-..000 ee ee eens ophidianus - 
FF. Adambulacral spines much flatter, furrow pair thinner and often somewhat 
spatulate, subambulacral much longer than thick......................4- guildingii 
EE. Rays flattened ventrally, with isolated papule between actinolateral plates..... perriert 
DD. RR eS5H5:4 Drs sistsa's i arscasaiere osteo ead OT TR Oo er a ahe eon ee ae see aienetoeretnlonee ae chinensis 
CC. Pedicellarize present. 
D. Adambulacral plates usually with a small supplementary spinelet at base of sub- 
ambulacral spine, between it and furrow spinelets; R=about 5.5r......... alexandri 
DD. Adambulacral plates with no such supplementary spinelet. 
E. R=7-9.5r or br; alveole of pedicellarie curved. 
F. Rays rather slender, conspicuously fluted; granules at base of subambulacral 
spines and between them and furrow spinelets, few, coarse, and scattered... rhabdotus 
FF. Rays stouter, not fluted; granules on actinolateral and ambulacral plates very 
numerous, small, and crowded, sheathing bases of spines. 
G. Alveole of pedicellarie form a semicircle...............00.00 cece eeeee duncani 
GG. Alveole of pedicellariz only moderately curved...................+.5- lioderma 
BH. Riaboutia oor brs alveole straicht a. eee cee niceties ludwigi 
BB. Marginal and often many abactinal plates on distal part of ray with conspicuous spinelets 
or spiniform granules. 
C. Rays stout; R about 4-4.5 br; distal spinelets moderate; actinal papular areas well 
developed; pedicellarie usually present................ 00 cc cece teeeee granifer 
CC. Rays more slender; R=5-7 br; distal spinelets well marked; actinal papular areas only 
on basal part of ray and even wanting in some young individuals; pedicel- 
lari wanting ei s5i4 sei th ee ee ee ee ee eee armatus 
AA. One or more granules present between furrow spinelets on inner surface of furrow. 
B. Madreporite single. 
C. Papular pores numerous (10 to 20 in each area); pedicellarie very numerous on porif- 
erous areas, which are conspicuous. 
D. Pedicellariz with elliptical alveole, whose ends have several notches to correspond 
with wide, serrate (3 or 4 teeth) blades of pedicellariw.................... confertus 
DD. Pedicellarize with boat-shaped alveole, whose pointed ends sometimes have a single 
median notch to correspond with narrow blade of pedicellaria, which ends in 
a single long, slender tooth (with or without a little tooth at the base on one 
or both sides) or in a pair of such teeth. 
E. Papular areas wider (or higher) than long, distinct but crowded; little or not at 
all sunken; abactinal plates, numerous, rather small, little elevated........ agassizti 
EE. Papular areas somewhat diamond-shaped, about as wide as long, decidedly 
sunken; abactinal plates larger and decidedly elevated at center........... kermadecensis 
CC. Papular pores few (3 to 8 in each area); few or no pedicellariw; poriferous areas not 
conspicuous. 
D. Ray, measured alongside, about 7 times its basal width; principal color purple.... pustulatus 
DD. Ray, measured alongside, only about 5 times its basal width; principal color bright red squameus 
BB. Madreporites 2. 
C. Pedicellarie narrow; 2 (1 to 3) teeth at ends of alveol; subambulacral spine very short, 
wide, and blunt, scarcely projecting even at tip................--000+00 cribrarius 
CC. Pedicellariz wide; 5 (4 to 6) teeth at ends of alveole; subambulacral spines a little longer, 
more pointed and more free. 
D. Rays flattened orally, tapering; granules at center of abactinal plates not much en- 
larged, little larger than adjoining papular pores...............--.0e+0005 robillardi 
DD. Rays cylindrical, blunt, scarcely tapering; granules at center of abactinal plates 
much enlarged, several times as large as largest adjoining papular pores... . lorioli 
