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 toa 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 antenne 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 antennse 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 thatare 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 
