REPORT ON THE HOLOTHURIOIDEA. 95 



curved simple, slightly spinose, spicula about 0*2 mm. long, partly of three- or four-armed 

 cruciform bodies with the arms slightly curved. On the dorsal surface, which is rather 

 rough, four-armed bodies (PI. XXXV. fig. 5), of variable shape, arc found closely 

 crowded together ; their arms are more or less strongly arcuated and spinose, attain a 

 length of 0"24 mm., and give off one or more processes ; from the centre of these deposits a 

 long spine runs out which gives the surface of the integument its roughness. The 

 tentacles as well as the pedicels are strengthened by some slightly curved spinose spicula ; 

 the latter have no supporting terminal plates. 



From want of material I have not been able to examine more closely the cal- 

 careous ring ; but judging from what I have observed, its structure must be of 

 great interest. The ring seems to be composed of five separate pieces resembling 

 those in the family Elpidiidas, but instead of a few rods running out in opposite 

 directions, each piece consists in this species of an innumerable number of rods, 

 which anastomose and form a kind of network which becomes most obvious towards 

 the centre of the pieces. In the connective tissue, which surrounds the calcareous 

 ring, a great number of deposits are found resembling in shape those of the ventral 

 perisoma. The polian vesicle is about 20 mm. long. The madreporic canal, which 

 seems to communicate with the exterior by a pore, contains a great number of deposits 

 in the form of irregular unbranched or three- to four-armed, generally strongly 

 spinose spicula. The ambulacral cavities of the small dorsal processes are very minute, 

 wlide each of the two canals of the azygous appendage communicates with a large slightly 

 curved and branched ambulacral cavity (PI. XL. fig. 7). The cloaca being very wide fills 

 up the posterior part of the peritoneal cavity, but it has no cagcal prolongation. The 

 reproductive organ (PI. XLVI. fig. 4), in the female, consists of two unbranched tubes 

 about 32 mm. long, the posterior half of which is enlarged and sacciform, with many 

 tuberculose prominences ; the organ opens externally by a pore situated about 25 to 30 

 mm. behind the anterior extremity of the body. 



The individuals from Station 300 are of gigantic size, the largest having a length of 

 about 375 mm., and a breadth anteriorly of from 110 to 120 mm. The mouth is situated 

 45 to 50 mm. behind the anterior extremity of the body, and the anus about 20 mm. in 

 front of the posterior extremity. The brim is very broad, especially round the anterior and 

 posterior extremities. One of the specimens is of a light grey or somewhat violet colour, 

 the other, on the contrary, is dark violet or rather black. The dorsal ambulacra carry 

 anteriorly only six processes about 5 mm. long, which arc indistinctly arranged in pairs. 

 The large azygous appendage situated about 110 mm. from the posterior extremity of the 

 body attains in its contracted state a length of 35 to 40 mm. and a breadth of 25 to 

 30 mm. at its base ; probably it was considerably larger when fully extended. At the 

 top of the appendage two small papillae are distinguishable which are in communication 

 with the two canals. The calcareous bodies, which are of the same shape as those in the 



