230 
THE VOYAGE OF H.M.S. CHALLENGEE. 
Habitat. — Mediterranean Sea (Grube, Heller, von Marenzeller, Grseffe, Ludwig, &c.). 
(Mus. Holm.) Three specimens from Lesina, presented by von Marenzeller. All the 
ambulacral appendages being withdrawn into the body-wall, it is almost impossible 
to determine their true appearance. They seem to be of nearly equal size, and 
to be equally distributed all over the body. A closer microscopical examination 
reveals the fact that the ventral are more like pedicels in having a larger terminal 
plate, bilateral perforated rod-like nearly smooth plates, and strong rods with 
obtuse spines round the margin ; some small holes occur in the slightly enlarged 
ends of the rods. In the dorsal papillae the rods are smoother and the terminal 
plates rudimentary. As in Holothuria poU, the tables are more rare and their 
disk is reduced to a spinous ring ; the spire terminates in about twelve teeth. 
The buttons have the same aspect as those in the species just mentioned — namely, 
rounded or oval, with none, two, four, six, or even more holes — but they are 
always densely covered with minute conical elevations, consequently their surfaces 
are very rough. The dorsal buttons are commonly larger, with more distinct holes. 
Holothuria mammata, Grube, 1840; Ludwig, 1879.. Holothuria tubulosa, Semper, 
1868 {partim). 
The dorsal papillae often placed on hemispherical warts, forming five or six irregular 
rows. The ventral pedicels not very crowded, fewest at the middle of the ventral 
surface. 
Habitat. — Mediterranean Sea (Grube, Ludwig). 
(Mus. Holm.) Four specimens from Salerno or Amalfi, agreeing in all respects with 
the description of Ludwig. In the spaces between the large characteristic hemi- 
spherical warts, small ambulacral appendages may be found. The deposits seem 
to be in an advanced state of solution, but bear a certain resemblance to those 
of Holothuria tubulosa or Holothuria stdlati, with which species this form must 
be closely allied. The tables are rather incomplete, with a simple annular disk 
and a spire made up of four rods and one transverse beam. The dorsal papdlas 
have a rudimentary terminal plate and numerous curved rods with some spines 
or perforations. The ventral pedicels have a well-developed terminal plate 
surrounded by bilateral perforated elongate plates and irregularly perforated 
rods. 
Holothuria pleuripus {Cystipus) , Haacke, 1880; Ludwig, 1883. 
Habitat. — Mauritius (Haacke, Ludwig). 
According to Ludwig, this species resembles the following one in habit as well as 
in the shape of the ventral deposits ; in the dorsal perisome, on the contrary, 
the long buttons are altogether covered with knobs, and the tables are very 
remarkable in having the disks almost completely reduced and the spire trans- 
formed, the tables themselves acquiring a spherical aspect. In the Zoological 
