136 THE ECHINODERMS OF TORRES STRAIT. 
very conspicuous. The species has a wide range from Minikoi and Ceylon on the west to 
Pinnacle Island, Riu Kiu Islands on the north, and the Solomon and Loyalty Islands on 
the southeast. It is common all through the East Indies, especially at Amboina. At Mer, 
annulosa is one of the commonest brittle-stars. The coloration is very characteristic, but 
occasional albinos occur which are a nearly uniform cream-color; in some of these the 
distal portions of the arms have the usual red, white, and black shades. Specimens under 
10 mm. in disk-diameter are not so red as adults, the arm-plates are very different, and the 
claviform spines are wanting; when only 5 mm. across the disk, there are no specific char- 
acters like those of the adult, except the whitish disk-spines, and these are not numerous. 
Unlike some other members of the genus, annulosa does not often occur among the living 
corals, but is most abundant under rocks and coral slabs. It is very active, and as soon 
as its sheltering rock is overturned it moves rapidly to a new shelter. 
Kent (1893, Great Barrier Reef, p. 121, pl. x1, fig. 11) records Ophiomastix annulosa 
from the Cairncross Islands (on the coast of Queensland and just south of the Torres Strait 
region). His description indicates that he had a sea-star of some sort in hand, but his 
figure is more like a brittle-star. Neither the form nor colors are those of an Ophiomastix, 
nor is there any indication of the claviform spines. Nevertheless, there is no other brittle- 
star any more like his figure than annulosa, and it is not at all improbable that the species 
has reached the Cairncross Islands. It does seem strange, however, that none of the 
naturalists of the Challenger or the Alert, nor Dr. Semon, nor our own party, found even 
one specimen of this very common species in the vicinity of Thursday Island or Badu or 
the Cape York peninsula. 
Ophiomastix janualis. 
Lyman. 1871. Illus. Cat. M. C. Z., No. 6, p. 14, pl. i, figs. 13, 14. 
(Plate 14, Figure 5.) 
The holotype of this species is so youthful that it is difficult to assert just how the 
adult would appear, but, after comparison with the material obtained at Mer, I have not 
hesitated to call the Murray Island specimens janualis. Yet Lyman’s specimen was sup- 
posed to come from the coast of Bolivia! No ophiocomid is known from the western coast 
of South America, and if an Ophiomastix should be found there the relation to the Murray 
Island form would require reinvestigation. The differences between janualis and liitkeni 
seem to be mainly in the coloration, and yet they are so marked it is very unlikely the two 
forms are identical. 
The only known locality for janualis is Mer,’ where we found it fairly common among 
Porites, Pocillopora, and Acropora, well out on the southeastern reef-flat. It never seemed 
to occur under rocks or coral slabs. It is one of the most active ophiurans I have ever 
seen, and it is no simple matter to capture a specimen uninjured. The largest specimen, 
28 mm. in disk-diameter, damaged all of its arms, but other specimens show that the arms 
are nine or ten times as long as the disk is wide. There is practically no diversity in color, 
except that the amount of yellow along the margins of the oral shields and arm-plates is 
a trifle greater in some specimens than in others. 
Ophiomastix liitkeni. 
Pfeffer. 1900. Abh. Senckenb. Nat. Ges., 25, p. 83.—H.L. Clark. 1915. Mem. M.C. Z., 2, pl. 16, figs. 3, 4. 
This species is very similar in proportions and form, and in the disk-covering, to 
janualis, but the pattern and shades of coloring are very different. Careful examination of 
material in the Museum of Comparative Zodlogy from the Philippine Islands shows that 
two specimens supposed to be janualis are really liitkeni. One of these is a Challenger 
specimen, originally called caryophyllata and afterwards janualis. The other is a later 
' For specimens from the Philippine Islands listed as janualis, see litkent. 
