32 THE VOYAGE OF H.M S. CHALLENGER. 



base. Integument very thin and soft, with smal] papillae ; calcareous deposits of two 

 sorts : large, straight, spinose spicula, much scattered ; and small ones more close set, in 

 the form of a C. 



Colour in alcohol, light grey, inclining to violet. Length, about 70 mm. Breadth, 

 about 33 mm. 



Habitat.— Station 160. March 13, 1874. Lat. 42° 42' S., long 134° 10' E. 

 Depth, 2600 fathoms ; bottom temperature, 0"2° C. ; red clay. One specimen. 



Only a single specimen having been obtained, it has been impossible to examine 

 it more in detail. The terminal part of the tentacles is rather large, about 6 mm. 

 in diameter, discoidal, and deeply incised in its outer margin, thus giving rise to 

 two rather large processes ; the whole terminal part, consequently also those two 

 processes, are provided with a great number of very small, retractile, unbranched projec- 

 tions. At the first sight the processes of the dorsal surface (PL XLIV. fig. 2) seem only 

 to be two, measuring in length about 20 mm., but by more careful examination, one 

 finds that each of those consists of two, that is to say, that another process, considerably 

 smaller, exists on the outer side of each of those first mentioned, and is united with 

 them by a web, only the top being visible. The integument is very thin, soft, and 

 transparent, and is covered all over with small papillae, which are most numerous and 

 conspicuous on the pedicels and the tentacles as well as at the top of the processes. In 

 each papilla are to be found minute fibres, which are probably nerves. The calcareous 

 deposits (PL XXXIII. fig. 17) resemble perfectly those in Scotoplanes globosa, the 

 large straight spicula being very rare, but the C-shaped ones more numerous and close 

 set. The last mentioned deposits are in this species usually slightly longer, more arcuated, 

 and almost thread-like The pohan vesicle is small. The rnadreporic canal seems to open 

 externally by a rounded pore ; however, I have not been able to prove this. 



Scotoplanes papillosa, Theel (PL II. figs. 5, 6). 



El 'pii.1i 'a papulosa, Preliminary Report on the Holothurid<e, pp. 16, 17. 



Body ovate, about once and a half as long as broad. Mouth anterior, terminal. Anus 

 posterior, slightly dorsal. Tentacles of almost equal size, bearing at their terminal part 

 numerous small digitiform processes. Pedicels eight along each side of the ventral 

 surface. The dorsal surface with four small processes disposed in a transverse row a 

 little in front of the middle of the back and united by their bases, forming a low ridge 

 between the two ambulacra; and immediately behind this ridge another pair of small 

 processes. Integument very thin, soft, and transparent, with small light papillae, 

 scattered on the back ; calcareous deposits of two sorts : large straight spinose spicula, 

 and small ones, more numerous and curved like a C. 



Colour in alcohol, fight grey. Length, 56 mm. Breadth, 34 mm. 



