34 THE VOYAGE OF H.M.S. CHALLENGER. 



Scotoplanes murrayi, The'el (PI. III. figs. 3, 4). 



Elpidia murrayi, Thdel, Preliminary Report on trie Holothuridae, p. 16. 



Body ovate, about twice as long as broad. Mouth, anterior, subventral. Anus 

 posterior, terminal. Tentacles of nearly equal size ; the middle ventral one a little 

 smaller than the others ; their terminal part provided with small, digitiform, retractde 

 processes. Pedicels short, five along each side of the ventral surface. The dorsal surface 

 with three small processes, as long as half the breadth of the body or shorter, disposed 

 on each of its ambulacra ; the posterior pair rudimentary. Integument brittle and glassy 

 from numerous crowded spicula, covering one another, some small and in the form of a 

 C, others large, unbranched, straight, and very spinose. 



Colour in alcohol glassy. Length, about 20 mm. Breadth, about 10 mm. 



Habitat.— Station 152. February 11, 1874. Lat. 60° 52' S., long. 80° 20' E. 

 Depth, 1260 fathoms ; diatom ooze. One specimen. 



I regret that but one specimen of this very pretty little species should have been 

 obtained. It closely resembles, in general form, the typical Elpidia glacialis. The back 

 is extremely convex. Some of the tentacles (PL XLIV. fig. 4) are evidently smaller than 

 the others, which is especially the case with the middle one on the ventral surface, and 

 the second one counting from that to the right. The processes on the dorsal surface are 

 arranged so that the first pair is situated on the anterior part of the body, the second one 

 on its posterior part, and the third rudimentary one immediately behind the second. The 

 processes of the two first pairs measure about 3 mm. in length. The pedicels, as well as 

 the tentacles and processes, are brittle and fragile on account of the large, slightly 

 curved, generally spinose and transversely placed spicula. As in JEljyidia glacialis, 

 the ends of the pedicels as well as the minute processes of the tentacles are com- 

 pletely retractile and, as it seems, destitute of deposits. The integument is brittle, 

 rough, and glassy ; it contains quantities of close-set, straight, or curved spicula 

 (PI. XXXIV. fig. 2), measuring in length about 0"8 mm., and provided with large 

 spines. Between those large spicula are to be distinguished small C-curved bodies, 

 measuring about 0"13 mm. in length or sometimes less. Those last-mentioned deposits 

 change considerably in size, but principally in form, some being extremely and equally 

 arcuated, others being very slightly curved, while others, lastly, are almost perfectly 

 straight, excepting their two nearly evenly arcuated ends. A series of dark spots 

 appears on the dorsal surface, which, however, does not seem derived from pigment 

 in the integument, but from some internal objects. Only a single specimen having 

 been at my disposal, and that a very small one, it has not been possible to study any of 

 the internal organs. 



