REPORT ON THE CRUSTACEA MACRURA. 289 



broken off, but I suppose they are long and slender, as in the other species. The 

 stylocerite is reduced to a rudimentary condition. 



The second pair of antennas possesses a scaphoccrite that reaches beyond the distal 

 extremity of the peduncle of the first pair, and the synaphipoda of the mandibles equal it 

 in length. The second pair of gnathopoda extends to nearly the length of the carapace 

 beyond the frontal margin, but supports only the rudiment of an ecphysis attached to 

 the basisal joint. 



The anterior three pairs of pereiopoda are moderately long and very slender; the 

 posterior two pairs are very long and slender but rather more robust than those of other 

 species, their great length being due to that of the meral and carpal joints. 



The pleon is free from the small spines so characteristic of the carapace, and is smooth, 

 except that it has a small tooth at the posterior extremities of the dorsal surface of the 

 last two somites, and a longitudinal ridge that traverses the lateral walls of the several 

 compressed somites in a position corresponding with the union of the somites to the 

 coxal plates. 



The tip of the telson is broken, but as it is it reaches very nearly to the extremity 

 of the inner branch of the tail fan, which is nearly equal in length to the outer branch, 

 which carries a small tooth on the outer side near the distal extremity, and possesses 

 an imperfect diaeresis. The branchiae are arranged as in the type species, but the 

 mastigobranchial lash consists of long and broad plates attached transversely to long 

 pedicles. 



Like many of the specimens recorded from extreme depths, the external tissue is of a 

 submembranous character. 



This species is represented in the collection by two specimens taken near the middle of 

 the South Pacific Ocean at a depth of nearly three mdes. 



Haliporus l&vis, Spence Bate (PL XLII. fig. 2). 



Haliporus Ixvis, Sp. B., loc. cit. 



Carapace submembranous, smooth, free from small hairs or spines over the surface. 



Rostrum about one -fourth the length of the carapace, horizontal, straight, armed on 

 the upper surface with six teeth, and two larger and more distant on the gastric region ; 

 one orbital tooth and one in a line posterior; one antennal tooth, one immediately behind 

 it, and one on the hepatic region. 



The pleon is laterally compressed, smooth, and slightly carinated dorsally. The 

 sixth somite terminates abruptly, with a tendency to form a small tooth. 



Telson long and slender, laterally compressed and grooved dorsally, armed with one 

 long spine-like tooth on each side near the extremity. 



Ophthalmopod half the length of the rostrum ; tubercle on the inner side small. 



(ZOOL. CHALL. EXP. — PART LII. 1886.) Fff 37 



