172 
THE VOYAGE OF H.M.S. CHALLENGER. 
Pseudostichopns villosus, var. violaceus, nov. (PL X. fig. 6b). 
Habitat. Station 156, February 26, 1874; lat. 62° 26' S., long. 95° 44' E.; depth, 
1975 fathoms; Diatom ooze; one specimen. 
This variety is distinguished by its dark violet colour. No other characters 
distinguishing it from the main forms have been observed. The tentacles are twenty 
in number. The vertical furrow, in which the downwardly directed anus is situated, 
is very distinct. The minute pedicels are numerous and distributed all over the body, 
and therefore also over the ventral surface, the foremost part of which, however, seems 
to be almost naked. Nor processes nor papillae are visible. Length of the specimen 
about 170 mm. The body is oblong and more tapering posteriorly. Mouth ventral in 
position. The intestinal canal is of a dark violet colour. The calcareous ring (PI. X. 
fig. 6b) has a somewhat different form, which, however, probably depends upon the 
degree of contraction. The slightly branched genital tubes have a considerable width, 
and are, like those in the main forms, collected into two thick bundles, one at each side 
of the dorsal mesentery. The two respiratory-trees run out from a common base. 
Genus Holothuria, Linne, 1758, 
Ilolothuria mouacana, Lesson, 1830 (PI. VIII. fig, 10). 
Habitat. — Fiji Islands; two specimens. Ternate (Molucca Islands); one individual. 
Owing to the animals being highly contracted and wrinkled, their true size and shape 
are very difficult to distinguish. However, the body seems to be more or less markedly 
cylindrical, tapering equally towards each extremity. The length of the largest 
specimen is about 100 mm. The tentacles are twenty in number, and retracted within 
the body. The mouth is surrounded by a crown of small papillae. The anus also carries 
some small, more irregularly disposed papillae. The ventral pedicels seem to be more 
numerous than the dorsal papillae. Both kinds of ambulacral appendages seem to 
reach about the same size, though the papillae are broader at the base. When fully 
extended they attain a length of about 4 mm. or slightly more. In consequence of 
the papillae being mostly completely retracted, it is not easy to distinguish their 
conical form from the cylindrical one which characterises the pedicels. But a few 
papillae, being extended, evidently show that they are true papillae. The sucking- 
disks of the papillae are minute in comparison with those of the pedicels, and there 
also exists, of course, a great difference in size between the respective terminal plates. 
Owing to the contracted and wrinkled state, the arrangement of the pedicels in three 
longitudinal series is not very clear. Probably for the same reason, the dorsal papillae 
do not present any distinct arrangement in longitudinal rows. 
