128 THE ECHINODERMS OF TORRES STRAIT. 
dental papille are numerous and crowded, sometimes more than 20. The coloration, rich 
brown with almost golden-yellow markings, is remarkably constant and makes the species 
very easy to recognize. The geographical range extends from Zanzibar and the Red Sea 
to the Paumotus and Hawaiian Islands, but there is no evidence of its reaching southern 
Japan on the north or continental Australia on the south. At Mer, pica was one of the 
rarest brittle-stars, and only 4 specimens were found. All were taken far out on the reef- 
flat, among the living corals, in such situations as O. erinaceus frequented. 
Ophiocoma canaliculata. 
Liitken. 1869. Add. ad Hist. Oph., pt. 3, p. 46, 99—Koehler. 1904. Mém. Soc. Zool. France, 17, p. 75, 
figs. 30-32. 
Few members of the family are as rare or as little-known as this isolated form, occur- 
ring in Bass Strait and on the southern coast of Victoria. My friend, Mr. J. Gabriel, who 
has sent me many echinoderms from that region, has secured but 1 specimen in the past 
7 or 8 years, although he feels sure that 10 or 12 years ago it was quite common at a spot 
which has been spoiled as a collecting-ground by certain harbor improvements. The species 
is a very distinct one, quite different from any other member of the genus, particularly in 
the form of the arm-spines and the large adoral plates. Nothing is known of the colors in 
life, but the dry specimen before me is light brown, with a distinctly green tinge on the 
disk, and with the arms quite reddish. 
Ophiocoma riisei. 
Liitken. 1859. Add. ad Hist. Oph., pt. 2, p. 141, 148, pl. iv, figs. 6a-6d. 
This well-defined West Indian species ranges from Bermuda to Brazil, but it has not 
yet been found in the eastern Atlantic. It reaches a large size. The biggest one I have 
seen measures 32 mm. across the disk and has arms 160 mm. long. While the general 
impression, especially in life, is that the color is uniformly black, careful examination of 
dried specimens often reveals some evidence of a color-pattern on the disk, and in young 
specimens this may be quite marked, and the arms are evidently banded, at least distally, 
with light and dark red-brown. The rust-red tentacles are a very constant and convenient 
specific character. Perhaps the most remarkable feature of this species is the late stage 
at which the granules of the disk appear; a specimen 5 mm. across will usually have no 
granules whatever, and this is true of one dry specimen at hand, 8 mm. across. Of course 
such specimens do not seem to be Ophiocomas and are sure to give difficulty in identification. 
Ophiocoma ethiops. 
Liitken. 1859. Add. ad Hist. Oph., pt. 2, p. 141, 145.—H. L. Clark. 1915. Mem. M. C. Z., 25, p. 291, pl. 
18, figs. 6, 7. 
This is the Panamic representative of echinata and scolopendrina, distinguished from 
them easily by the single tentacle-scale; the basal pores, even far out beyond the disk, 
may have two, but there is never any doubt that one is the typical number. The colora- 
tion is much like that of echinata, black or black marked, variegated, or banded with 
whitish. In size, ethiops is the largest of Ophiocomas. The biggest specimen in the 
Museum of Comparative Zodlogy is 40 mm. across the disk and has arms 240 mm. long 
and 6 mm. wide. Of course Bell’s (1887) record of ethiops from the Andaman Islands is 
based on a misidentification. Perhaps the specimen or specimens concerned were the form 
for which Koehler has revived Miiller and Troschel’s name wendtii (q.v.). 
Ophiocoma scheenleinii. 
Miller and Troschel. 1842. Sys. Ast., p. 99.—H. L. Clark. 1915. Mem. M.C. Z., 25, p. 293, pl. 15, figs. 1, 2. 
The status of this species admits of much discussion. Its resemblance to erinaceus 
is so obvious and striking that Matsumoto considers them unquestionably identical. No 
