GAMMARELLA. 329 



A MPHIPODA . QA MMARTDES. 



NAT ATOM A. 



Genus— GAMMARELLA . 



Oammarella. Spence Bate, Ann. Nat. Hist. 2 ser. xix. p. 143. Cat. 



Amph. Crust. Biit. Mus. p. 179. White, Hist. Brit. 



Crust, p. 181. 

 Gammarus part . Dana, U. S. Explor. Exped. p. 956. 



Generic character. Superior antenntB furnished with a 

 secondary appendage. Gnathopoda very unequal iu size in the 

 male, subchelate. Posterior pair of pleopoda unibranched. 

 Telson single cleft. 



The superior antennae in this genus are longer than 

 the inferior, and furnished with a secondary appendage. 

 The hands of the first two pairs of legs are subchelate. 

 The caudal appendages have their branches short, the last 

 pair are furnished with but a single branch. The central 

 tail-piece is single, but divided at the apex. 



This genus forms a curious link between the family 

 Orchestiida, and the subfamily Gammarides, possessing, as 

 it does, the superior antennae of Gammarus, and caudal 

 appendages similar to those of Oi'chestia. It moreover 

 appears to differ from Crangonyx only in having the 

 second pair of hands in the male larger than the first. 



