66 Carl Bovallius, The Oxycephalids. 



The pleon is about as long as the whole perseon. The under 

 margins of the first two segments are straight, that of the third convex, 

 and all are without tooth-like projections. 



The last coalesced ural segment is about a fourth part longer 

 than broad. 



The first pair of uropoda reach to the apex of the last 

 pair, and almost to the apex of the telson; the peduncle is con- 

 siderably longer than the inner ramus, which is as long as the outer, 

 and both are strongly serrated. The second pair do not fully reach to 

 the apex of the last pair; the peduncle is a little longer than the inner 

 ramus, which is a little longer than, and more than twice as broad as, 

 the outer; both are serrated. The third pair are a trifle shorter than 

 the telson; the peduncle is shorter than the rami, which are equal in 

 length, and serrated. 



The telson is about a third part longer than broad, triangular, the 

 margins being convex and smooth. 



CoLOUß. Almost hyaline, the ocular pigment dark brown. 



Length. 10—16 mm. 



Hab. The tropical region of the Atlantic. 



5. Oxyceplialiis latirostris, C. Claus, 1879. 



Pi. II, fig. 7-12; and p. 42, fig. 84. 



Diagn. The body is compressed, the peraeonal segments are smooth. 



The head is a little shorter than the perseon, and has a short 

 rostrum. The hind part of the head is more than three 

 times as long as the rostrum. 



The front margin of the carpal process of the first two pairs 

 of perœopoda is longer than the hind margin of the meta- 

 carpus, which is pectinated, with comparative!}^ short teeth 

 and a few bordering bristles; the lower front corner of 

 the carpus is not protruding. The fifth pair are much longer 

 than the sixth. The femur of the sixth pair is narrowly 

 pear-shaped, a little broader than that of the fifth, and quite 

 as long as that of the seventh pair, which is itself shorter 

 than all the following joints together. 



