174 THE ECHINODERMS OF TORRES STRAIT. 
of those unpleasant means of defense. The living animal, as noted at Mer, is white 
or whitish, with few, scattered, brown-red spots or small blotches, essentially as shown in 
Semper’s figure. 
I do not believe the records of arenicola from Surinam and Bahia are trustworthy, 
but apparently the species does occur at the Galapagos Islands and at Cocos Island, 
Mexico, as well as at Hawaii and Tahiti. Several recent writers have revived Brandt’s 
name maculata for this species, but even if we grant that Brandt’s maculata is identical 
with arenicola, his name can not be used, as it is antedated by H. maculata of Chamisso 
and Eysenhardt, as Fisher (1907) has pointed out. 
Holothuria argus. 
Bohadschia argus Jaeger. 1833. De Hol., p. 19, pl. 2, figs. 1, 1b. 
Holothuria argus Semper. 1868. Holothurien, p. 80, pl. xxx, figs. 11a, b. 
This is one of the most conspicuous and unmistakable members of the genus. It has 
a wide range, from the Seychelles to Tahiti, north to the Riu Kius and south at least to 
Cooktown, Queensland, and probably much further. It is not recorded from the Thursday 
Island region, but we found it not uncommon at Mer on the southeastern reef-flat. Kent 
(1893) has given an excellent figure of argus, in connection with a full account of its rela- 
tion to the Australian béche-de-mer industry. He calls it “leopard” or “‘spotted fish,” 
a more appropriate name than “‘tiger-fish,” the name given to me as in use in the Torres 
Strait region. I can not altogether suppress the suspicion that the name “‘tiger-fish”’ 
originated in a mistake of someone who had heard the name “‘leopard-fish” and on en- 
deavoring subsequently to recall it got no nearer than “‘tiger!’’ 
Holothuria atra. 
Jaeger. 1833. De Hol., p. 22.—Semper. 1868. Holothurien, pl. xxvi. 
This widespread and perplexing species has been exhaustively studied by C. L. 
Edwards (1908), and the distinction between it and H. floridana has been brought out 
well. But a careful study of growth-changes and of individual diversity associated with 
habitat is still greatly needed. It is not at all improbable that at least two distinct species 
are still confused under the name atra. Oddly enough, in spite of its being one of the 
commonest of Indo-Pacific holothurians, atra has not hitherto been recorded from Torres 
Strait, though Kent (1893) lists it from the Barrier Reef. We found it common at Madge 
Reef, Thursday Island, at Friday Island, at Erub, and at Mer. We had previously noted 
it as common at Tahiti, very abundant at Rarotonga, Cook Islands, and common at Green 
Island, Queensland. 
At Mer, one of the native fishermen brought me two very large and very black holo- 
thurians, which he called ‘“‘lolly-fish’’ and which he said were found only in deep water 
(2 to 3 fathoms or more) outside the reef. He said they made very valuable béche-de-mer. 
So far as I can see from the examination of spicules, these “‘lolly-fish”’ are only very large 
individuals of atra, yet the shallow-water specimens were considered worthless by the 
fishermen. I can only account for this on the ground that as atra reaches maturity it 
leaves the reef-flat and passes into deeper water, where the body-wall becomes thicker and 
harder, and the full size (450 to 600 mm. in length) is attained, making the animal suitable 
for béche-de-mer. Specimens 200 to 300 mm. long are not black in life when examined 
closely, but deep chestnut-brown or occasionally red-brown. This is only noticeable when 
the skin is stretched. These reef-flat specimens often become more or less fully covered 
with sand or sediment, attached to the body-wall apparently by mucus. This coat may 
be continuous, but it often flakes off in patches, and it is usually better developed dorsally 
than ventrally. Cuvier’s organs seem to be quite wanting. 
