266 
GAM MARINE. 
AMPHIPODA. 
NAT ATOM A. 
GA MM A RIDES. 
Genus— EUSIRU S . 
Eusirus. Kroyer, Tidsk. (2), p. 801. Spence Bate, Cat. Amph. Brit. Mns. 
p. 154. 
Generic character. Like Atylus, except that the superior 
antennse are furnished with a secondary appendage. The 
gnathopoda have the carpi considerably produced inferiorly, and 
attached to the upper margin of the propoda. Propoda large 
and equal. 
This genus in its general aspect nearly agrees with 
Atylus, but is separated from it by some important 
features. The head is not anteriorly produced into a 
rostrum. The superior pair of antennae are furnished 
with a secondary appendage. The hands of the first two 
pairs of legs are large and of the same form, the wrists 
articulating with the superior rather than with the 
posterior margin, and being considerably produced in- 
feriorly corresponding with the posterior margin of the 
hands. The legs generally are slender, and about the 
same length. The posterior caudal appendages are 
double-branched, and the middle tail-scale is cleft at the 
apex. 
This genus was founded by Kroyer to receive a species 
dredged by Holboll on the coast of Greenland. 
An imperfect specimen is as yet the only British 
representative of this genus. 
