AMPELISCA GAIMARDIF. 
127 
A MPIIIPODA . 
NAT ATOM A. 
AMPELISCIDES. 
Specific character. Posterior margin of the third segment of the pleon 
plain. Superior antennae one-third the length of the animal. Inferior an- 
tennas very slender, two -thirds the length of the animal. 
Length, § inch. 
Ampelisca Gaimardii. Kroyer, Yoyage en Scand. Crust, pi. xxiii. fig. 1. 
Spence Bate, Cat. Amph. Brit. Mus. p. 91, pi. 
xy. fig. 1. 
Araneops diadema. A. Costa, Bend, del Aecad. Sc. di Nap, 1853, p. 
171, Tav. i. fig. 1. 
Tetromatus typicus. Spence Bate, Brit. Assoc. Bep. 1855, p. 58. Synop. 
Ann. Nat. Hist. ser. 2, xix. p. 139. White, Hist. 
Brit. Crust, p. 171, pi. x. fig. 4. 
The anterior half of the animal is much more com- 
pressed than the posterior, and narrowed to an angle 
upon the dorsal surface, the angle increasing anteriorly 
to the extremity of the head. The eyes consist of simple 
