AMATIllLLA. 359 



AMPHIPODA. GAMMARIDES. 



NATATORIA. 



Genus— AM ATH ILL A. 



Amuthia.* Rathke, Fauna der Krym. Spence Bate, Rep. Brit. Assoc. 

 1855, p. 58. Ann. Nat. Hist. 2 ser. xix. p. 143. Cat. 

 Amph. Brit. Mas. p. 197. White, Pop. Hist. Brit. Crust, 

 p. 182. 



Generic character. Head produced to a short sharp poiut 

 between the antennae. Antennae rather short, subequal in 

 length, the upper appeudiculated. Gnathopoda with small 

 subequal propoda. Body and tail carinated ; and destitute 

 of spines. Telson entire, slightly emarginate at the tip. 

 Three posterior pairs of pleopoda sub-equal, one of each pair 

 of rami slightly smaller than the other, those of the last pair 

 more foliaceous and equal. 



In all the species of this genus the back is elevated 

 into a carina, which is most strongly developed along the 

 caudal segments. The eyes are normal. The antennae 

 subequal ; the superior pair being furnished with a 

 secondary appendage about one-third of the length of 

 the flagellum, and composed of four oblong articuli, 

 whereas the articuli of the flagellum of all the an- 

 tennae are extremely short. The first two pairs of 

 legs are small, subequal, uniform, and subchelate. The 

 walking legs are subequal. The last pair of the caudal 

 appendages terminate in two branches of equal length, 

 and do not extend beyond the branches of the preceding 

 appendages. The central tail-piece is single. 



* The name Aniatliia Laving been long ago proposed by Lamarck for a genus 

 of Polyps, by Pol. Roux for a genus of Decapod Crabs, and liy Duponcliel for 

 a genus of Moths, we have, to avoid confusion, slightly altered the name. 



