V>()G AMl-niPODA NOKMALIA. 



length of the animal. First pair of gnathnpoda larger than the 

 second ; propodos broad-ovate ; palm slightly concave and oblique, 

 armed with nine or ten short truncated teeth and several hairs ; 

 dactylos arcuaie, haWng an obtuse projection near the centre. 

 Second pair of gnathopoda having the propodos long-quadrate ; 

 palm slightly concave, not oblique, armed with seven or eight 

 short truncated teeth ; inferior margin indented posteriorly to the 

 palm, and fm-nished ■\^ith several fasciculi of long hairs. Pereio- 

 poda subequal, spinous. Posterior pair of plcopoda having the 

 rami unequal, the outer being three times longer than the inner. 

 Telson not spinous. 

 Length 1 inch. 



Hah. Behring's Straits {Sthnpson, to whom I am indebted for the 

 specimen from which the figure and description are taken). 



4. Gammarus Locusta. (Plate XXXVI. fig. 6.) B.M. 



Cancer Locusta, Linn. Faun. Siiec. 2nd edit. p. 497 ; Syst. Nat. p. 1055, 

 Cancer (Gammarus) Locusta, Montagu, Linn. Trans, ix. p. 92. t. 4. f. 1. 

 . Gammarus Locusta, Leach, Edinb. Encijc. art. Crust, p. 402; Linn. Trans. 

 xi. p. 359. 



L)esmarest, Consid. sur les Crust, p. 267. 



Edwards, Ann. des Sc. Nat. xx. p. 369 ; Hist, des Crust, iii. p. 44. 



Kriiyer, Gronl. Amjip. p. 27. 



Rathhe, Fauna dcr Xrym, p. 372. pi. 5. f. 11. 



White, Hist. Brit. Crust, p. 182 ; Cat. Biit. Crust, in B. M. p. 51; 



Cat. Crust. B. M. p. 87. 

 Gosse, Mar. Zool. i. p. 141. f. 257. 

 Zaddach, Synops. Crust. Pruss. Prodr. p. 4. 

 Bruzelius, Skand. Amph. Gamm. p. 52. 

 Gammarus Duebenii,ii;'//"f6or</, Of vers, af Kongl. Vet. Akad. Forhandl. 



1851, p. 22. 

 Gammarus mutatus, Liljehorg, Offers, af Kongl. Vetensk. Akad. For- 

 handl. 1852, p. 447. 



Three anterior segments of the pleon ha^ing the infero -posterior 

 angle produced to a shai-p, posteriorly directed point. Eyes long, 

 reniform, white. Superior antenna having the first two joints of 

 the peduncle subequal in length, and, together, rather longer than 

 the cephalon, the third not more than half as long as the second ; 

 flagellum long and slender, being four times as long as the pe- 

 duncle; secondary appendage one-third as long as the primary. 

 Inferior antenn® nearly as long as the superior, having the last 

 three joints subequal, and extending nearly the whole length of 

 the last joint beyond the peduncle of the superior. Gnathopoda 

 having the coxse as deep as their segments : first pair shorter than 

 the second, having the carpus increased to the breadth of the pro- 

 podos ; propodos ovate, palm convex, not defined, having the infe- 

 rior and superior margins fringed ^^-ith fasciculi of hairs : second 



