REPORT ON THE HOLOTHURIOIDEA. 29 



P. Body ovate or oval. 



a. Calcareous deposits : four-armed, almost cruciform bodies, with 



five outwardly directed processes, .... Elpidia rigid 'i. 



b. Calcareous deposits : four-armed bodies with the arms running 



out two from each opposite side of a long spicule, and 

 provided with two outwardly directed processes ; and small 

 scattered hat-shaped wheels, .... Elpidia glacialis. 



II. Pedicels only around the posterior half of the ventral surface. 



a. Calcareous deposits : four-armed bodies with one or two out- 



wardly directed processes, ..... Elpidia verrucosa. 



b. Calcareous deposits : four-armed bodies with four outwardly 



directed processes, ...... Elpidia purpurea. 



c. Calcareous deposits : four-armed bodies with four outwardly 



directed processes ; and small wheels with eight to ten 



spokes, ....... Elpidia ambigua. 



Scotoplanes, 1 n. gen. 



Body varying from more or less elongated to ovate, almost globular, from once 

 and a half to thrice as long as broad, sometimes depressed posteriorly. Tentacles ten. 

 The dorsal surface with a small number of processes, often of remarkable length and 

 size. The ventral surface with pedicels all along each side or only round its posterior 

 half. Integument with two sorts of calcareous deposits : small spicula, curved in the form 

 of a C ; and either large, straight, unbranched spicula, or three-armed bodies. 



Scotoplanes globom, Thdel (PL IV. and PI. V. fig. 3). 



Elpidia globosa, Theel, Preliminary Report on the Holothurida?, p. 14. 



Body ovate, more or less globular, from once and a half to twice as long as broad. 

 Mouth anterior, terminal, slightly ventral. Anus posterior, subventral. Tentacles of 

 equal size, their terminal parts bearing numerous, small, digitate, retractile processes. 

 Pedicels seven along each side of the ventral surface, rather large. The dorsal surface, 

 with three processes, disposed on each side of its ambulacra ; the first pair in the anterior, 

 and the second in the posterior part of the back, both of them very large elongated and 

 conical ; the third pair immediately behind the second, small and rudimentary. Integument 

 very thin and transparent, with two sorts of calcareous deposits : small spicula, curved in 

 the form of a C ; and large straight spinose ones. 



Colour in alcohol, light grey. Length, about 130 mm. Breadth, about 70 mm. 



Habitat.— Station 157. March 3, 1874. Lat. 53° 55' 8., long. 108° 35' E. 

 Depth 1950 fathoms ; diatom ooze. One specimen. Station 299. December 14, 1875. 

 Lat. 33° 31' S., long. 74° 43' W. Depth, 2160 fathoms; bottom temperature, l'l" C. ; 

 Grey mud. Twenty-five to thirty specimens. 



1 2xwo; = darkness 



