330 



AMPIIIPODA, 



N ATA TORI A . 



GAMMA RID.E. 



GAM MA RIDES. 



GAMMARELLA BREVICAUDATA. 



Specific character. Superior antennae half the length of the animal. 

 Inferior antennas scarcely longer than the peduncle of the superior. First 

 pair of gnathopoda small ; second pair having the propodos very largely 

 developed. Posterior pair of pleopoda having the ramus not longer than the 

 peduncle. Telson as broad as long. 



Length \ inch. 



Gammarus brevicaudatus. 

 Gammarella brevicaudata. 



Gammarella orchestiformis. 

 Gammarus punctimanus. 



Milne Edwards, Ann. des Sci. Nat. t. xx. 



p. 369. Hist, des Crust, t. iii. p. 53. 

 Spence Bate, Cat. Amph. Crust. Brit. Mus. 



p. ISO, pi. xxxii. fig. 8. 

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



White, Hist. Brit. Crust, p. 181. 

 Costa, Mem. Reale Accad. d. Sci. di Napoli, 



vol. i. tav. iii. fig. 6, 1853. 



The dorsal surface in this species is slightly elevated 

 at the posterior portion of each segment, especially in 

 the fourth segment of the tail, owing chiefly to the 

 smallness of the two succeeding segments, which appear 



