112 THE ECHINODERMS OF TORRES STRAIT. 
on them in the Alert Report (p. 141) they are typical, but as he says nothing about the upper 
surface of the arms, it is not certain. 
This very handsome brittle-star was rare at Mer, only 3 small specimens being found. 
At Thursday Island 2 large specimens with disks 10 to 12 mm. across were taken. The 
ground-color in life may be deep olive green or purple and the markings are orange, but 
in alcohol or on drying all traces of the orange disappear, green also tends to vanish, and 
the purple becomes more or less accentuated. In habits, martensi is secretive, all the speci- 
mens taken being dug out from crevices and cavities in the coral rock. 
Ophiothrix melanogramma. 
Bell. 1884. Alert Rep., p. 145. 
No one seems to have met with this fine species save Bell, who, besides describing 
it originally from Prince of Wales Channel, Torres Strait, later (1894) listed it from north- 
western Australia (86 fathoms) and from Macclesfield Bank (35 to 41 fathoms). It seems 
odd, in view of this distribution, that the Siboga failed to find the species anywhere in the 
East Indies. Bell has given no figures, nor does he even mention the size of the specimens 
he has studied. 
Ophiothrix melanosticta. 
Grube. 1868. Jahrsb. Schles. Ges. Vaterl. Cultur, 45, p. 45.—Koehler. 1905. Siboga Oph. litt., pl. viii, figs. 
4-6; pl. xiv, fig. 3. 
On September 13, 1913, we dredged near Goode Island, Torres Strait, in 2 to 3 fathoms, 
a little brittle-star about 2.5 mm. across the disk, which is perfectly tetramerous. The colors 
in life were bright green and red, and the specimen was prettily variegated, but after death 
the shades rapidly became paler and duller, and there is little evidence now of the former 
beauty. The characteristic brown spots or dots are still well marked, however. The 
Museum of Comparative Zoélogy has a larger specimen, about 4 mm. across the disk and 
with arms about 20 mm. long, from Borneo, in which the green tints as well as the brown 
spots are still evident, but the red has entirely faded. The Siboga found melanosticta at 
7 stations in the East Indies, some of the specimens having a disk diameter of 10 to 11 mm. 
Bell reports (1894) the species from northwestern Australia in 38 fathoms, and Koehler 
(1907) lists it from Port Hedland, West Australia, but it has not previously been known 
from Torres Strait. The type locality is China Sea, but Bell did not find it among the 
ophiurans from Macclesfield Bank. 
Ophiothrix nereidina. 
Ophiura nereidina Lamarck. 1816. Anim. s. Vert., 2, p. 544. 
Ophiothriz nereidina Miiller and Troschel. 1842. Syst. Ast., p. 115.—Déderlein. 1896. Jena. Denkschr., 8, 
pl. xvi, figs. 16, 16a. 
(Plate 15, Figures 2, 8, and 9.) 
The beautiful and very characteristic coloration of this lovely brittle-star can be 
better appreciated from the figures given than from any detailed description. The young 
individuals (pl. 15, fig. 8) have the pattern of coloration on the disk (fig. 9) much more 
sharply defined than do older ones (fig. 2). There is relatively little color diversity in the 
species, the only variations I have noted being in the exact shades of red, yellow (or white- 
ish), and blue, and in the relative proportions of these three colors. The species is common 
all through the East Indies, but does not seem to occur in the Pacific. It reaches the Mal- 
dive Islands and Réunion on the west, Misaki, Japan (where Matsumoto, 1917, reports 
it as common) on the north, and Fraser Island, Queensland, on the south. At the Murray 
Islands it was common, and as it was easily recognized on the reef, I noted that far out 
on the southwestern reef it was often associated with comatulids. It was commonly found 
in and among living corals or in the crevices of large coral fragments. It is noteworthy 
