REPOET OK THE HOLOTHURIOIDEA. 
231 
State Museum at Stockholm one of the original specimens which was brought 
home from Mauritius is preserved. Length, 50 mm. Colour — light greyish, 
here and there inclining to brownish. Body depressed, with a kind of brim at 
the area of transition between the dorsal and ventral surfaces. An alternating 
double row of small warts or papillae is to be found on the brim along each 
side of the body ; the dorsal surface bears similar scattered warts and numerous 
very minute papillae. The arrangement of the minute ventral pedicels in 
three longitudinal series is not very distuict. Tentacles minute. The ventral 
buttons are provided with three to seven pairs of holes, and usually with 
numerous distinct knobs on the margin as well as on the middle beam ; but, as 
a rule, the longer buttons have not their knobs so well marked. The ventral 
tables consist of a rounded, slightly convex disk, pierced with a larger central 
hole and several small peripheral ones, but their spire is low, often very irregular, 
sometimes built up of four rods and one transverse beam, and provided with 
several or numerous small teeth on the top ; sometimes the spire seems to be 
composed of more than four rods, thus almost resembling hemispheres, a result 
of the presence of secondary rods uniting the margin of the disk with the top 
of the spire, whereby the peripheral holes in the disk become placed inside these 
secondary oblique rods. Thus, the ventral deposits here described do not fully 
agree with those in Holothuria bowensis, as pointed out by Ludwig. All the 
buttons seem to be more or less uneven from the presence of knobs. The 
dorsal buttons bear very distinctly-marked knobs, and the tables of the same 
surface are considerably larger, resembliug perforated spheres or hemispheres. 
In the dorsal papillte the tables are often of a more regular and delicate con- 
struction, consisting of a small annular disk and a slender conical spire, built up 
of four rods and two to three transverse beams, the top itself terminating in a 
few small teeth. The pedicels and papillae are supported by numerous crowded 
rods, slightly perforated at the middle and at each end ; moreover, the pedicels 
contain oval bilaterally perforated plates and a larger terminal plate. In the 
Godeffroy Museum I have seen three specimens, two from the Fiji Islands and 
one from Tahiti, agreeing in all respects with the above description, excepting 
that the ventral pedicels are evidently arranged in three longitudinal series. 
Holothuria rigida (Stichopus), Selenka, 1867 ; Semper, 1868. 
Dorsal surface with papillae ; ventral surface with three rows of pedicels. The tables 
have a spire made up of “ eight ” rods and terminating in numerous teeth. 
Buttons of two kinds — oval knobbed ones with six, seldom eight, holes and a 
deeply undulated margin ; and large rounded spinous elliptical ones mostly 
pierced with six to ten holes, but often quite devoid of holes. 
Habitat. — Zanzibar, Society Islands, and Florida (Selenka). 
From the figure given by Selenka, it seems somewhat uncertain whether the oval 
buttons are entirely smooth or pro^dded with low rounded elevations. 
