276 SPECIFIC DESCRIPTION. 



The pleon is nearly symmetrical, being rather 

 larger on the left than the right side. Each 

 segment is defined by a marginal prominence ; 

 that upon the left side is continued from near 

 the middle to a process that terminates in a point 

 or tooth at the side ; but that on the right becomes 

 confluent with a posterior ridge, and forms an 

 irregular circle, the centre of which is deeply 

 depressed. 



The eyes are small, of a green colour, and 

 surmounted on denticulated peduncles. The 

 first pair of antenna? consist of three equal- 

 lengthened joints (of which the first is more 

 robust), together with a short, stout, pilose 

 flagellum, and a slender secondary appendage. 

 The second pair of antennae have a compound 

 scale, consisting of two large and two short com- 

 pressed processes, and the third joint is fur- 

 nished with two or three sharp strong processes. 

 The first pair of pereiopoda are chelate and strong, 

 echinated with blunt-pointed spines, and terminate 

 in fingers that are flattened at the extremity, and 

 furnished upon the outer surface with numerous 

 tufts of hair, that spring from the summits of 

 the numerous tubercles that are found there. 

 The second, third, and fourth pairs of pereiopoda 

 are more slender than the first, resemble one 



