MEGAMCERA OTHONIS. 
405 
AMP HIP OB A. GAMMAR1BES. 
NAT ATOM A. 
Specific character. Posterior and inferior margins of the third segment of 
the pleon serrated. Inferior margins of the coxae of the three anterior pairs 
of legs serrated. Gnathopoda subequal. Propoda ovate. 
Length \ inch. 
Gammarus Othonis. Edwards, Ann. des Sci. Nat. t. xx. p. 373, pi. x. 
fig. 11. Hist, des Crust, t. iii. p. 50. Spence 
Bate, Rep. Brit. Assoc. 1855, p. 59. Ann. Nat. 
Hist. 2 ser. xix. p. 144. White, Hist. Brit. Crust, 
p. 184. 
Megamcera Othonis. Spence Bate, Cat. Amph. Brit. Mus. p. 227, pi. 
xxxix. fig. 8. 
The animal is long ; and has the inferior half of the 
posterior margin as well as the posterior half of the 
inferior margin of the third segment of the tail serrated. 
The eyes are round and black. The superior antennae 
are about one-third of the length of the animal ; and the 
peduncle is as long as the flagellum, this latter portion 
varies from fourteen to twenty-five articuli, and the 
secondary appendage, which is short, from two to three. 
The inferior antennae are about one-third shorter than 
the superior ; the flagellum is not half the length of the 
