26fi GAMMARIM. 



AMPHIPODA . GAMMARIDES. 



NATATORIA. 



Genus EUSIRUS. 



Emir as. Kroyer, Tidsk. (2), p. 801. Spence Bate, Cat. Anipb. Brit. Mus. 

 p. 154. 



Generic character. Like Atylus, except that the superior 

 antennae 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 antennas 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. 



