ANNOTATED LIST. 171 
Pentacta cucumis. 
Colochirus cucumis Semper. 1868. Holothurien, p. 58, pl. xiii, fig. 17; pl. xiv, fig. 16. 
Sluiter (1894) records a single specimen of this species taken by Semon near Thurs- 
day Island. It was originally described from the Philippines, but has since been recorded 
from several stations in the East Indies, and also from Japan (Théel, 1886). 
Pentacta tuberculosus. 
Holothuria tuberculosa Quoy and Gaimard. 1833. Voy. Astrolabe, 4, p. 131. 
Colochirus anceps Semper. 1868. MHolothurien, p. 57, pl. xii, fig. 1; pl. xiii, fig. 15. 
Colochirus tuberculosus Semper. 1868. Holothurien, p. 239. 
In life this is a very noticeable holothurian, the red of the ambulacra contrasting 
strongly with the yellow of the interradii; both colors are, sometimes at least, more bril- 
liant than in Semper’s figure. Unfortunately, these fine colors are very fugitive, and, as 
Bell (1884) has pointed out, alcoholic specimens range in color from grayish-white or 
brownish-yellow to nearly black. On the sand-flat southwest of Friday Island two speci- 
mens of tuberculosus were found by us, September 13, 1913. One was about 75, the other 
about 100 mm. long. We did not find the species at the Murray Islands, but it is known 
from a number of stations on the Australian coast, as far south as Port Jackson, and the Alert 
took it in Torres Strait. Vaney (1912) lists it from the Aru Islands, and it is found thence 
northward to Amoy, Hongkong, and southern Japan, yet the Siboga did not meet with it. 
It is also known from Guam, and Quoy and Gaimard are supposed to have taken it at the 
Tonga Islands. There are specimens in the Museum of Comparative Zodlogy from Bowen 
Strait, on the northern coast of Australia, between Croker Island and Coburg Peninsula. 
Pentacta trimorpha' sp. nov. 
(Plate 37, Figures 1 to 8.) 
Length of alcoholic specimen, 10 mm.; diameter about 2.75 mm. Body quite dis- 
tinctly quadrangular, the ventral surface, occupied by the three ambulacra, somewhat 
wider than the dorsal side, occupied by the mid-dorsal interambulacrum and with the 
dorsal ambulacra forming its boundaries. Body-wall very firm and almost brittle from the 
abundance of calcareous deposits. Ambulacra extended anteriorly into triangular “valves” 
which could apparently close over the withdrawn tentacles. Pedicels, ventrally, relatively 
large, distinct, in a rather crowded and irregular double series in each ambulacrum; dor- 
sally, smaller and so fully contracted that both number and position are obscured. There 
are no evident dorsal papilla, but the sides and back of the animal are uneven and “‘lumpy.” 
Tentacles 10, the two ventral ones not half as large as the others. Calcareous ring (pl. 
37, fig. 1) low, with no posterior prolongations; each piece is concave behind and has a 
conspicuous anterior point; on the radial pieces this anterior prolongation is truncate and 
is wider than the pointed prolongation of the interradial pieces. 
Calcareous particles of the body-wall very numerous in three fairly distinct layers; 
the innermost is made up of heavy lenticular bodies (pl. 37, fig. 5) nearly a millimeter 
long, with the width one-half to three-fourths as much, composed of a coarse calcareous 
network with minute interspaces; the middle layer is made up of heavy knobbed plates, 
0.050 to 0.100 mm. long, each with 4 to 6 or more perforations (pl. 37, fig. 7); the outer 
layer consists of pretty little, oblong plates (pl. 37, fig. 6), 0.050 to 0.060 mm. in diameter, 
each with 4 major perforations and 4 minor ones at the corners; the outer surface is 
provided with conical knobs, but the projections of the inner surface are much more 
rounded; the plates are not perfectly flat, but are a trifle concave (pl. 37, fig. 8); if much 
more so, they would be like the “baskets” of Thyone; few of the plates are symmetrically 
developed. Pedicels with large supporting rods (pl. 37, fig. 4), about 0.160 mm. long and 
1 rpinop¢a= three-formed, in reference to the three kinds of calcareous particles in the body-wall. 
