'228 AMPniroDA nokmama. 



inferior mari!:iii.s serrated. Eyes round. Superior antennfc longer 

 tlian the inferioi- ; iirst and second joints of the peduncle long, 

 subequal, third very .short ; flagellum as long as the peduncle ; 

 secondary appendage short, consisting of from two to three articuK. 

 Inferior antcnna3 one-fourth the length of the animal ; pediuicle 

 longer than the flagellum. Gnathopoda subequal and unifonn ; 

 first pair rather the smaller, ha\ing the coxoe serrated along the 

 inferior margin ; carpus as long as the propodos ; propodos long- 

 ovate, tapering, palm oblique, not defined. Two anterior pairs of 

 perciopoda ha\Tng the inferior margin serrated ; three posterior 

 pairs subequal in length, having the bases in each ovate, with the 

 posterior margin serrated. Posterior pair of pleopoda having 

 the rami foliaceous, equal. Tclson double, and serrated at the 

 apex. The integument is rugose, being covered all over with 

 short angular scales or flat spines, which are only visible with a 

 microscope. 

 Length | an inch. 



Hah. Plymouth ; trawled (C. 8. B.) ; Polperro {Mr. Loughrhi). 



6. Megamcera Alderi, n. s. (Plate XL. fig. 1.) B.M. 



Third and fifth segments of the pleon having the posterior dorsal 

 margin produced into a tooth. Eyes round. Suj^erior antennfe 

 two-thirds the length of the animal ; flagellum twice the length 

 of the peduncle ; secondary appendage consisting of three articuli. 

 Inferior anteunce a little longer than the peduncle of the superior ; 

 peduncle as long as the peduncle of the superior. Eirst pair of 

 gnathopoda small, having the carpus a little longer than the pi-o- 

 podos ; propodos ovate, palm imperfectly defined ; inferior margins 

 of both carpus and propodos tufted with short hairs. Second pair 

 of gnathopoda moderately long ; propodos ovate, palm oblique, 

 defined by a blunt tooth. Third pair of pereiopoda shorter than 

 the two posterior. Posterior pair of pleopoda (wanting). 



Length ^ths of an inch. 



Hab. Coast of Northumberland (Mr. Alder). 



7. Megamcera brevicaudata. (Plate XL. fig. 2.) B.M. 



Gammarus brevicaudatus, Spence Bate, Brit. Assoc. Rq)07-t, 1855 ; Ann. 

 Nat. Hist. Feb. 1857 (not Edwards). 

 Wliite, Hist. Brit. Cmst. p. 185. 



Superior antennae one-fourth the length of the animal ; peduncle 

 three times as long as the flagellum. Inferior antennae two-thii-ds 

 the length of the superior ; peduncle three times as long as the 

 flagellum. Eirst pair of gnathopoda small, having the propodos 



