434 COROPHIIDJE. 



AMPHIPODA. PODOCERIDES. 



NAT ATOM A. 



Genus PODOCERUS. 



Podoccrus. Leach, Linn. Trans, xi. p. 360. Desmarest, Consid. sur 

 Crust, p. 269. Samouelle, Ent. Comp. p. 185. Ed- 

 wards, Hist, des Crust, t. iii. p. 63. Spence Bate, Ann. 

 Nat. Hist. 2 ser. xix. p. 148. Gosse, Mar. Zool. p. 141. 

 White, Hist. Brit. Crust, p. 197. Bruzelius, Skand. 

 Amph. Ganim. p. 20. 



Jassa. Leach, Linn. Trans, xi. p. 361. Desmarest, Consid. sur 



Crust, p. 269. White, Hist. Brit. Crust, p. 198. 



Ischyrocerus. Kroter, Gron. Amfip. p. 59. 



CratopJiium. Dana, U. S. Explor. Exped. p. 841. 



Elasmoims. Costa, Rend, della Reale Accad. delle Scienze di Napoli, 

 1853, p. 170. 



Generic character. Superior antennae having a minute 

 secondary appendage. Inferior antennas, not multiarticulate, 

 robust; ilagelluni short and tipped with hooks. Second pair of 

 gnathopoda having the propodos largely developed. First and 

 second pair of pereiopoda having the base very broad; third 

 pair having the coxa scarcely as deep as that of the preceding 

 pair, and the lobes not equal in size. Posterior pair of pleopoda 

 biramous, one ramus being furnished with one or more hooks. 

 Telson squamiform. 



This genus has the eyes generally very small, and 

 situated on a very prominent lobe, projected laterally 

 between the superior and inferior pairs of antennae ; this 

 lobe is formed of a plate so thin that we have frequently 

 observed the ocular mass to stand as a projecting ball on 

 the inner side. The superior antennas are invariably 

 furnished with a secondary appendage, which is generally 

 very small. The inferior antennas are longer, and more 

 powerful than the superior ; the peduncle is long, and 

 the flagellum very stout and strong, never multiarticulate, 



