236 
THE VOYAGE OF H.M.S. CHALLENGER, 
Habitat . — Celebes (Jaeger, Semper). 
The above description of the deposits is in conformity with the figures given by 
Semper. The species is distinguished from Holothv/ria acuhata even by the 
want of supporting rods in the papillae. 
Holothuria alhiventer. Semper, 1868 . 
The tables have the large rounded disk perforated with numerous smaller holes and 
the margin smooth ; the short spire is formed by six to ten rods (instead of four, 
which is the common number), and its large hemispherical top is covered with 
small spines or teeth. The oval symmetrical buttons have six holes and two 
knobs on the middle beam. 
Habitat . — Philippine Islands, Amboina, and Eed Sea (Semper). 
(Mus. Godeffroy.) One specimen from the Pacific Ocean. Tentacles slightly 
unequal. Mouth ventral, surrounded by a crown of small papiUse. Five 
indistinct groups of small rough papillse or papilliform elevations at the anus. 
Ambulacral appendages — rigid rough papUlae of obviously conical form, those 
on the ventral surface larger and fewer than the dorsal ones which are more 
crowded and more unequal in size. Colour — ventral surface dirty grey and 
finely punctated, with the papillae whitish ; dorsal surface dark almost blackish- 
brown ; tentacles yellowish-brown. A single Polian vesicle and madreporic 
canal, the latter rather long and like an elongate vesicle. The calcareous ring 
has the radial pieces much more deeply furrowed anteriorly than is indicated 
by Semper. The disks of the tables are rather large, smooth on the margin, and 
perforated by numerous small holes, the central of which are of about the same 
size as the rest ; the under surface of the disks is distinctly convex. The spire, 
sometimes longer, sometimes shorter, is built up of more than four, not unfrequently 
about ten, rods, and terminates in a rounded very spinous top ; a side view of 
the spire often presents some minute superposing holes, indicating the presence 
of two or three transverse beams, which, however, are very indistinct. Among 
these tables I find some scattered ones with more elongated spires. The typical 
form of buttons is the oval one, with six holes and two distinct knobs on 
the middle beam, and with a series of rounded, sometimes very indistinct, 
sometimes, on the contrary, rather prominent elevations round the margin. 
Here and there other buttons may be seen of a more elongated shape and 
furnished with more holes and knobs. The ventral papillae contain the follow- 
ing deposits — knobbed buttons like those in the body-wall itself ; tables of the 
above mentioned kind as well as others with the spire much longer, narrower, 
having five to eight transverse beams and often some spines on the sides ; smooth 
curved supporting rods with some holes at the middle and at the ends ; and 
some elongated, bilateral, perforated plates round the rudimentary terminal plate. 
The dorsal papillae seem to be devoid of such bilateral perforated plates, and 
-have the terminal plate much more fragmentary or even absent. 
