186 THE ECHINODERMS OF TORRES STRAIT. 
spicuous, acute thorns on the side; if the secondary branches do not divide they bear 1 to 4 
such thorns, and indeed these thorns may occur anywhere on the rods. Of course, few 
rods are perfectly symmetrical, and it is rare indeed to find two alike, but, as a rule, the 
primary branches are longer than the original rod; tertiary branches are present, and 
there are at least some conspicuous, slender thorns. The stout rods are usually about 
0.050 mm. long, with the original rod about 0.009 by 0.005 mm., the primary branches 
about the same or a little longer and the secondary branches a little shorter and very acute. 
Thorns are frequently developed, but tertiary branches rarely occur. There seem to be 
no connecting-links between stout and slender rods, and the latter are very much more 
numerous, perhaps 25 to 1. Here and there I have found the slender rods with a rough, 
warty, or corroded surface, but I believe these are artifacts. Pedicels, when fully devel- 
oped, with a very finely reticulate terminal plate but with no supporting rods; a few of 
the dichotomously branched rods may be elongated at right angles to the axis of the pedicel 
and have a few anastomosed branches, but such are infrequent and inconspicuous. ‘Ten- 
tacles without supporting rods, but with a small number of widely scattered plates, 0.050 
to 0.075 mm. across formed by anastomosis of the branches of the branched rods. Much 
more numerous, but not particularly abundant, are little rods, about 0.060 mm. long, 
which may be bent, curved, or straight and smooth or rough at the tips. Color, in life, 
white, blue, brown, and yellow, as shown in plate 18, figure 3; the ventral side was pure 
white, the back pale blue, the large papillee whitish at base, yellow distally, and dark brown 
at tip; dorsally the pedicels were brown, usually with darker tips, but ventrally they were 
white with dark or light brown or yellow tips. Tentacles bright brown. In alcohol, all 
blue and yellow shades have disappeared and the animal is now yellow-brown above, 
whitish below, everywhere more or less thickly speckled with the deep brown tips of the 
pedicels. Tentacles dingy yellow-brown. 
Holotype: M. C. Z. No. 1068; off the northwestern reef, in several fathoms, Mer, 
Murray Islands, Torres Strait. 
This very fine holothurian was brought to the laboratory by one of the native fisher- 
men, who got it by diving. He called it an ‘‘amber-fish,”’ but I have failed to find any 
such name used for béche-de-mer in the Torres Strait region. The species was evidently 
not a novelty to the natives, who spoke of it as a “‘prickly-fish”’ and as one of the most 
desirable kinds. We saw no other specimens at Mer, nor did we find it at the Barrier 
Reef, where ananas was not uncommon. The differences from ananas, in color and in 
form of dorsal papille, are so striking (cf. pl. 18, figs. 2 and 3) it is hard to believe the two 
species are really congeneric; but the resemblances in calcareous particles and in internal 
organization are even more remarkable. 
Stichopus chloronotus. 
Brandt. 1835. Prod. Descr. Anim., p. 250.—Selenka. 1867. Zeit. f. w. Zool., 17, p. 315, pl. xvii, figs. 20- 
24; pil. xviii, fig. 25. 
(Plate 18, Figure 2.) 
This is one of the commonest and most easily recognized of Torres Strait holothurians, 
the form and color being characteristic and showing little diversity. We saw it at Thurs- 
day Island and at Erub, as well as at the Murray Islands. It lives in the open, on flats 
covered with ‘‘eel-grass’’ (Posidonia) and is never found under rocks or among corals. 
The largest specimen seen was only a little more than 300 mm. long. The color is always 
deep green; in bright sunshine the green is very obvious even in the darkest specimens, 
but in poor light many of the larger specimens look almost black; the distal portion of 
the big dorsal papilla 7s blackish, with the extreme tip brown-orange; tentacles ashy with 
the stalks whitish; pedicels dark ashy. Mitsukuri (1912) says the specimen he collected 
at Amami-Oshima was ‘‘deep black with a bluish tinge, the tips of some papille being 
