REPORT ON THE CRUSTACEA MACRURA. 



859 



of 20 fathoms, in the China Sea, and also near the Island of Loochoo. Of the 

 Challenger specimens of this genus, Leptochela serratorhita was taken off St. Thomas 

 Island, West Indies, and Leptochela robusta in Bass Strait, while Leptochela gracilis 

 was captured near the southern coast of Japan. 



Leptochela serratorhita, n. sp. (PL CXXXIX. fig. 1). 



Orbital margin fringed with a series of small teeth. Dorsal surface of the fifth 

 and sixth somites of the pleon smooth. 



Second pair of gnathopoda furnished with a large and pointed tooth. 



Habitat. — St. Thomas, West Indies ; shallow water. One specimen, associated with 

 Platybema rugosum. 



The carapace is smooth and anteriorly produced to a sharp horizontal rostrum. The 

 orbit extends to the first antennal tooth, and has the margin serrate ; the second antenna! 

 tooth is reduced to a point ; the lateral plates of the first somite of the pleon overlap 

 the posterior margin of the carapace, and the dorsal surface of the posterior somites is 

 unarmed and smooth. 



The telson is as long as the lateral plates of the rhipidura. 



The ophthalmopoda are shorter than the rostrum, robust, and have the ophthalmus 

 orbicular, and but little larger in diameter than the stalk. 



The first pair of antenna? is subequal and short. 



The second pair of antennas has the scaphocerite longer than the peduncle of the 

 first pair, and the flagellum slender (broken). 



The mandibles are broad, flat, and serrate at the margin, with sharply cut teeth 

 that are largest towards the front, and furnished with a short ovate single-jointed 

 synaphipod, tipped with six ciliated hairs. 



The first pair of siagnopoda is three-branched ; the inner branch is small and the 

 middle broad and foliaceous, both being tipped with hairs ; the third, which appears to 

 represent the basecphysis, is narrow and two-jointed, the terminal joint being small and 

 bud-like. 



The second pair of siagnopoda consists of four plates ; two on the inner surface which 



