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



with two pairs of rather long slender processes directed forwards, one a little behind the 

 other. Integument thin, transparent, rather rough, with numerous crowded calcareous 

 deposits, composed of four long, spinose, more or less arcuated arms, each bearing a long, 

 spinose process. 



Colour in alcohol, violet. Length, about 37 mm. Breadth, about 16 mm. 



Habitat. — Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. Depth, 

 1600 fms. ; bottom temperature, 0'8° C. ; globigerina ooze. One specimen. Also a single 

 individual was dredged at Station 157. March 3, 1874. Lat. 53° 55' S., long. 108° 

 35' E. Depth, 1950 fathoms; diatom ooze. 



I intend first to describe a little more in detail the individual from Station 147, and 

 then to point out by what this differs from the one dredged at Station 157. The body 

 is elongated, almost oval, with the posterior end evenly rounded ; the anterior, on the 

 contrary, is suddenly truncated. The back is but slightly convex, and the ventral 

 surface almost flat, the body thus looking rather depressed. The mouth is completely 

 ventral and situated a little behind the foremost truncated part of the body. That 

 part which projects in front of the mouth consists of a brim or border-like enlargement 

 of the body -wall, which gives to the foremost end of the body the appearance of being 

 very thin and flattened. This brim carries at its front on each side a pliable non- 

 retractile process, 10 or 11 mm. in length, and a little behind each of those, another one 

 of about the same length or a little shorter. The processes as well as the brim are directed 

 forwards but can probably, at the will of the animal, be bent upwards ; they belong to 

 the dorsal ambulacra. The tentacles (PI. XLIV. fig. 6) are of almost equal size, and their 

 terminal part is provided round the edge with a number of small retractile processes of 

 which two seem to be a little larger than the others ; besides, the terminal part carries 

 a great number of papilla-like retractile projections of a dark violet colour. We have 

 not succeeded in observing any tentacle completely extended. Pedicels are wanting 

 on the anterior half of the body ; round its posterior half, however, they are arranged 

 to the number of fifteen or sixteen. The calcareous deposits of the integument 

 (PI. XXXIII. figs. 13, 14), which are numerous and very crowded, are composed of a more 

 or less elongated central part, from each of the ends of which run out two long, spinose, 

 more or less arcuate, arms, with the ends somewhat widened ; near its attachment each 

 arm bears a long spinose process. Even the pedicels, tentacles, and dorsal processes 

 are provided with a great number of deposits of the same shape, both the first 

 ones having, besides, at their ends some curved, slightly spinose spicula, and some 

 four-armed bodies without processes, and with the arm considerably spinose and arcuate. 

 The colour of individuals preserved in alcohol is violet, with the back a little darker ; 

 the terminal parts of the tentacles are almost black violet. 



The calcareous ring does not seem to be continuous, but consists of five pieces 

 separated one from another, each being composed of a number of rods radiating in two 



