GAMMARID.E. 229 



oTiito, palm convex and imperfectly defined; second pair much 

 larger than the first, having the carpUs short, the propodos long- 

 ovate, palm ol)h(]ue and defined hy a small tubercle. Tliree posterior 

 pairs of pereiopoda subccpial, having the basa oval, the mera pro- 

 duced cUstally both anteriorly and posteriorly, the carpi robust, the 

 propoda increasing in diameter distallj-, the dactyla short. Poste- 

 i-ior pair of pleopoda short, scarcely reaching beyond the penulti- 

 mate ; rami equal, very short, not longer than base. Telson 

 double. 

 Length -^'oths of an inch. 



Hub. PljTiiouth {C.S. B.) ; Moray Frith {llev, G. Gordon). 



This species was originally described under the impression that it 

 was identical with Gcunnuirus brcvicaadatus of Edwards; but an 

 examination of the tj-pe, preserved in the Museum of the Jardin 

 des Plantes, has enabled me to correct the mistake. 



8. Megamcera longicauda. (Plate XL. fig. 3.) 



Gammarus longicauda, J]ra7idt, Middendorff^s Sibirische Reise, p. 141. 

 pi. G. f. 32. 



Three anterior segments of the pleon having the posterior margins 

 serrated, and the two succeechng segments denticulated upon the 

 dorsal surface. Eyes round. Superior antenna) nearly as long 

 again as the inferior, having the joints of the peduncle subequal ; 

 fiagellum longer than the peduncle ; secondary appendage scarcely 

 as long as the last joint of the peduncle. Inferior antennae longer 

 than the peduncle of the superior ; fiagellum a little longer than 

 the last joint of the peduncle, Eirst pair of gnathopoda smaller than 

 the second, having the carpus as long as the propodos ; propodos 

 ovate, palm obhquc, not defined ; dactylos short, arcuate. Second 

 pair of gnathopoda having the cai-pus much shorter than the pro- 

 podos ; propodos ovate, palm oblique, imperfectly defini'd, ciliated ; 

 dactylos short, arcuate. Posterior pair of pleopoda long, ha\iug 

 one long and one short ra^nus. 



Hab. Asiatic Eussia ? 



The animal, which is described from Erandt's figure in Count 

 Middendoi-ff"s ' Sibirische Reise,' closely resembles, and may be iden- 

 tical with, Gammarus dentattis of Kroyer. 



0. Megamcera Krdyeri. (Pl.vti; XL. fig. 4.) 



Ganuiiarus Krijyeri, Ih-ll, App. to Belc/wr's Last of the Arctic Voyayes, 

 p. 405. pi. 34. f. 4 (not (himnianis Krciycri, Rathke). 



Pleon having a row of short spines i>ii tbc posterior edge of the 



