MEGAMCERA ALDERI. 
407 
A MPHIP OB A. GA MM A PI DES. 
NATATORIA. 
Specific character. Posterior dorsal margin of the third and fifth segments 
of the pleon produced to a small tooth. Second pair of gnathopoda larger 
than the first, having the propodos ovate, palm oblique, serrated, and defined 
by a tooth. 
Length 5 S o inch. 
Megamcera Alderi. Spence Bate, Cat. Amph. Brit. Mus. p. 228, pi. xl. 
fig. 1. 
The third segment of the tail is posteriorly produced 
in the middle of the dorsal margin into a small point. 
The fourth does not appear to he so produced, whilst the 
fifth has a small central, and close upon each side a large 
lateral, tooth. The eyes are round or oval. The su- 
perior antennae are about two-thirds of the length of the 
animal ; the flagellum longer than the peduncle, and the 
secondary appendage consisting of three articuli. The 
inferior antennae reach a little beyond the peduncle of 
the superior. The first pair of legs have the wrist 
longer than the hand ; the palm is oblique and longer 
than the inferior margin. The second pair of legs are 
larger than the first ; the hand is nearly of the same form, 
