182 AMPniPODA NOilMALIA. 



shorter than the superior. Coxae not deeper than their respective 

 segments, those of the third pair of pereiopoda shorter than those of 

 the foiu'th. First pair of gnathopoda small ; second pair of gnatho- 

 poda very large. Pereiopoda subequal. Posterior pair of pleopoda 

 having the rami very unequal, the outer one extending much be- 

 yond the preceding, the inner being rudimentary. Telson double. 



The differences between this gen.as and Gammarella are very 

 slight ; the most important being the form of the telson, and the 

 most distinguishable the respective lengths of the rami of the 

 posterior pair of pleopoda. 



1. MeUta palmata. (Plate XXXIII. fig. 2.) 



Cancer (Gammarus) palmatus, 3fotitagu,Linn. Trans, vii.p. 69. t.6.f.4. 

 Melita palmata, Leach, Edinb. Encyc. art. Crust, p. 403 ; Tratis. Linn. 

 Sue. xi. p. 358. 



Desmarest, Consid. sur les Crust, p. 264. pi. 45. f. 7. 

 Gammarus Dugesii, Edwards, Ann. des Set. Nat. xx. p. 368 ; Hist, des 

 Crust, ill. p. 54. 

 Zaddach, Si/n. Crust. Pruss. p. 6. 

 Gammarus palmatus, Liljehory, Of vers. afKongl. Vet. Akad. Forhandl. 

 1854, p. 453. 

 Frey u. Leiickart, Beitr. z. Kenntn. Wirhellos. Tliiere, p. 162 (from 



BruzeJius). 

 Edw. Hist, des Crust, iii. p. 55. 

 Science Bate, Brit. Assoc. Report, 1855 ; Synopsis, dfc. Ami. Nat. 



Hist. Feb. 1857. 

 White, Hist. Brit. Crust, p. 184. 

 BruzeJius, Skand. Amj^h. Gamm. p. 56. 

 Gammarus inequimanus, Spetice Bate, Synopsis, SfC, Ann. Nat. Hist. 

 Feb. 1857. 



Pleon having the second and third segments serrated along the infe- 

 rior margin, the posterior margin of the fourth segment dorsally 

 developed in the median line into a small tooth, and the posterior 

 margin of the fifth having a small tooth on each side of the central 

 line, with one or two small spines. Eyes round or subovate. Su- 

 perior antennse a little longer than the inferior ; pedimcle much 

 longer than the flagellum, secondary appendage triarticulate. In- 

 ferior antennae having the peduncle quite as long as the peduncle 

 of the superior ; flagellum scarcely longer than the last joint of the 

 peduncle, eight-articulate, the first articulus being as long as the 

 three succeeding. Fii'st pair of gnathopoda small, having the carpus 

 longer than the propodos ; propodos ovate, palm convex, imper- 

 fectly defined ; dactylos arcuate. Second pair of gnathopoda very 

 large ; cai-pus short : propodos as long as the cephalon and first 

 two segments of the pereion, superior margin arcuate, inferior 

 straight, fringed with fasciculi of hairs ; palm convex, imperfectly 

 defined, inferior angle rounded (the outer surface of the propodos is 



