210 
THE VOYAGE OF H.M.S. CHALLENGER. 
II. Tables of a more common shape, with the disk mostly small, annular, or completely 
reduced, and with a spire built up of four rods and one transverse beam. 
1. In addition to tables with com'pletely reduced disks, large characteristic 
unbranched bars, more or less richly covered with protuberances or 
small elevations. 
Holothuria jiavo-maculata. Semper, 1868. 
Ambulacral appendages — pedicels alone. Only the spire of the tables is left. The 
four rods which constitute the spire are united at the base so as to form a 
rounded conical top instead of a disk ; near this top each rod seems to bear a 
small spine. The opposite ends of the rods, which form the truncated outwardly 
directed part of the spire, terminate each in four diverging teeth. The bars are 
large, elongate, fusiform, thick at the middle, and rough from numerous small 
protuberances. 
Habitat. — Navigator Islands (Semper). 
A comparison of the above description , of the tables with the figure drawn by Semper 
suggests the idea that Semper saw the tables with the upper part undermost, 
a supposition founded on reasons given under the next species. Possibly the 
same is the case with Ludwig’s Holothuria imitans, which agrees in most 
respects with this species, but differs from it in having the characteristic 
rough bars only present in the ambulacral appendages. 
Holothuria surinamensis, Ludwig, 1875. 
Ventral pedicels more numerous than the dorsal papillae. Deposits almost like those 
in the preceding species. 
Habitat. — Surinam (Ludwig). 
When comparing the descriptions of Semper and Ludwig, one can scarcely detect 
any characters to distinguish this species from the preceding, except differ- 
ences in the ambulacral appendages and number of madreporic canals and 
Polian vesicles. As will be seen below, there exist, however, some differences 
even in the shape of the calcareous bars. Since I have had the oppor- 
tunity of examining four specimens of Holothuria surinamensis dredged at Mexico, 
and kept in the Zoological State Museum at Stockholm, I am able to complete the 
description of Ludwig. The largest specimen attains a length of 200 mm., and 
agrees in all respects with Ludwig’s types. Colour — dark rusty-brown, inclining 
to greyish on the ventral surface ; ends of the pedicels whitish ; papillae and 
a small space round their base light yellowish rusty-brown ; numerous well 
marked dark brown spots on the back. Anus with five not very distinct groups 
of papillae. The numerous tables bear the closest resemblance to those figured 
by Ludwig as well as to those in Holothuria fiavo-maculata, but Ludwig, and 
