REPORT ON THE CRUSTACEA MACRURA. 823 



third somite projecting slightly over the anterior dorsal margin of the fourth. Sixth 

 somite about twice as long as the fifth. 



Telson nearly as long as the sixth somite, and furnished at the dorsolateral margin 

 with a longitudinal series of distant spinules. 



First pair of antennae having the peduncle subequal in length with the rostrum, and 

 carrying two unequal long flagella. 



Second pair of antennae armed with a tooth at the lower distal extremity of the first 

 joint, and carrying a scaphocerite that is subequal with the rostrum and armed with a 

 stout tooth at the outer distal extremity. 



Second pair of gnathopoda having the several joints long, and terminating in a slender 

 curved dactylos. 



Observations. — There is only one specimen of this genus in the collection, and that 

 is imperfect. It corresponds with Nematocarcimis in all respects, excepting in the form of 

 the second pair of gnathopoda. 



Stochasmus exilis, n. sp. (PI. CXXXII. fig. 14). 



Carapace about one-third the length of the animal, having a rostrum about one-third 

 the length of the carapace, and armed with more than twenty long spinules closely 

 pressed together on the upper surface, and none upon the lower. The antennal tooth is 

 long and slender and that at the fronto-lateral angle is short. 



The ophthalmopoda are short. 



The first pair of antennae has the peduncle subequal with the rostrum ; the first joint 

 is excavate on the upper surface, and has a sharp-pointed stylocerite that is about half 

 the. length of the joint ; it terminates in two long flagella. 



The second pair of antennae has the coxa armed with a long tooth on the lower distal 

 angle, and carries a scaphocerite that reaches considerably beyond the apex of the rostrum 

 and terminates in a tooth on the outer distal angle. 



The second pair of gnathopoda is long and slender, reaching nearly to the extremity 

 of the rostrum ; it has a long meral joint, a long and slender carpos, and a propodos that 

 is long and compressed, fringed with hairs on either side, and terminating in a narrow 

 extremity that articulates with a curved and slender dactylos. 



The pleon is laterally compressed and has the third somite posteriorly produced 

 to a point on the dorsal surface. The sixth somite is about twice the length of the 

 preceding. 



The telson is nearly as long as the sixth somite, and is furnished on each side with 

 six dorso-lateral spinules, with two long spines at the outer angles of the terminal 

 extremity, and with several intermediate stiff hairs. 



