716 



THE VOYAGE OF H.M.S. CHALLENGER. 



The pleopoda are biramose, the sixth pair being a little shorter than the telson and 

 furnished with a tooth on the outer distal angle. 



Observations. — I do not remember a species of any other form in which the lateral 

 margins of the pleon are serrate. This species differs from the preceding in having 

 basecphyses attached to the five posterior pairs of pereiopoda, but the immature stage of 

 the specimen precludes a too rigid generic classification. 



Caricyphus gibberosus, n. sp. (PI. CXXI. fig. 4). 



Carapace long, narrow, cylindrical, anteriorly produced to a small sharp-pointed 

 rostrum that is armed on the upper margin with three or four teeth. 



Pleon having the third somite posteriorly elevated to a large hunch ; sixth somite 

 longer than the preceding two. Telson nearly half as long as the sixth somite. 



Length, 



Habitat. — September, 1875, Pacific Ocean, near the Sandwich Islands; surface. 

 One specimen. 



The carapace is rather more than a third the length of the animal, and has the dorsal 

 surface anteriorly produced to a sharp-pointed rostrum, the upper margin of which is armed 

 with three or four teeth. The anterior two somites of the pleon are short and subequal ; 

 the third is dorsally long, and projects posteriorly to a rounded hunch-like prominence 

 that is produced horizontally in a line with the preceding somites ; the lateral margins are 

 shorter than the dorsal, and are anteriorly convex and posteriorly concave ; the fourth 

 somite inferiorly articulates with the posterior division of the third, and is, therefore 

 placed at a right angle with the preceding somites, it is shorter than the third, and sub- 

 equal with the fifth. The sixth is about three times the length of the fifth, and much 

 narrower, gradually narrowing posteriorly. 



The telson is about one-half the length of the sixth somite, and terminates in a 

 styliform extremity. 



The ophthalmopoda are ovate and scarcely longer than the rostrum (?). 



The first pair of antennae has the first joint about twice the length of the ophthal- 

 mopod, and the second and third subequal, short, and cylindrical. The flagella are 

 broken off. 



