REPORT ON THE HOLOTHURIOIDEA. 35 



Scotoplanes albida, n. sp. 



Body elongated, about twice as long as broad. Mouth anterior, terminal. Anus 

 posterior, dorsal. The terminal part of the tentacles circular discoidal, unusually large, 

 provided with small retractile processes. The dorsal surface with some small processes 

 on its anterior part. Pedicels very long, ten or eleven (?) along each side of the ventral 

 surface. Integument thin and soft, with two sorts of numerous calcareous deposits : 

 small spicula, curved in the form of a C ; and large, straight, spinose ones. 



Colour in alcohol, white. Length, about 75 mm. Breadth, about 35 mm. 



Habitat. — Station 143. December 19, 1873. Lat. 36° 48' S., long. 19° 24' E. 

 Depth, 1900 fathoms; bottom temperature, 1'4°C. ; globigerina ooze. One incomplete 

 specimen. 



Ordy a single specimen having been brought home by the Challenger Expedition, and 

 that such an incomplete one as to render a detailed examination impossible, the descrip- 

 tion must necessarily be rather imperfect. The ventral surface is flat, the dorsal on 

 the contrary convex. The anus is situated near the posterior end of the body, and 

 is completely dorsal. The tentacles, of which only seven are left, have the terminal part 

 very large, measuring about 10 mm. in diameter, and are furnished with a number of 

 small-branched processes round the edge ; besides those processes there are numerous 

 very small papilla-like projections. Only some small processes have been discovered 

 anteriorly on the dorsal surface, but how these are arranged I have not been able to 

 observe. The pedicels are very large, measuring in length about 14 mm. ; the posterior 

 pairs are much smaller. The integument is thin and destitute of papillae ; the calcareous 

 deposits in the form of a C (PI. XXXII. fig. 14) are numerous, varying in length from 

 0"056 mm. to O'l mm. ; the straight spinose spicula are very thinly scattered, and about 

 0'57 mm. in length. The pedicels and tentacles contain C-curved bodies, as well as larger 

 or smaller more or less arcuated spicula (PL XXXII. fig. 15) which are beset with spines 

 towards the ends. Only a single polian vesicle is to be observed. The cloaca is very 

 large, with a csecal prolongation. The madreporic canal seems to be without deposits. The 

 reproductive organ consists of a single, 15 to 20 mm. long, fascicle of numerous small caeca. 



This species bears a strong resemblance to Scotoplanes mollis and Scotoplanes 

 papillosa, but it differs from these especially by the number and size of the pedicels, as 

 well as by the large end of the tentacles, which greatly exceeds in dimensions the largest 

 known of these two species mentioned. 



Scotoplanes robusta, n. sp. (PL VI.). 



Body elongated, widest a little in front of its middle, about twice and a half as long- 

 as broad. Mouth anterior, subventral. Anus posterior, dorsal. Tentacles of almost equal 

 size ; their large, thick, and sole-like terminal part contracted, only two processes being- 

 visible in its outer margin. Pedicels, eleven along each side of the posterior half of the 



