fiA>ni.\nii).T;. 227 



margin of the basa serrated. Posterior ))air of plcopoda much 

 longer than the preceding, and having the rami nearly e(iual. 

 Telson double. 

 Length \ of an inch. 



llab. Pl^-moutli Sound (Prof. Kinahan and C. S. B.). 



4. Megaincera longimanus. (Plate XXXIX. fig. 7.) B.M. 



Gammarus longimanus, Leach, MS. li.M. Collection. 



T/ioi»pso)i,A/t)i.Xa(.IIkt.Oct.l847; Nat. Hid. oflrelaN(l,iv.i\S9(y. 



Spence Bate, Brit. Assoc. Report, 1855: Ann. Nat. Hist. Feb. 1857. 



^mte, Hist. Brit. Crust, p. 184. 



Gosse, JSIar. Zool. p. 141. 

 Gammarus Inevis, Bruzelius, Skand. Amph. Gamm. p. GO. pi. 2. f. 10. 



Animal long and slender ; back smooth ; second and third segments 

 of the pleon having the inferior margin serrated. Ej-es small, 

 nearlj- round. Superior antenncD about half the length of tho 

 animal ; first two joints of the peduncle long, subequal, third short ; 

 flagellum a little longer than the peduncle ; secondary appendage 

 having three or foiir articuli : peduncle of the inferior antennae as 

 long as the peduncle of the superior ; flagellum scarcely longer 

 than the last joint of the peduncle. First pair of gnathopoda 

 having the carpus and propodos long, slender, subequal ; propodos 

 slightly tapering, palm not defined ; dactylos short. Second pair 

 of gnathopoda ha\dng the meros produced anteriorly forwards and 

 downwards to a shai-p tooth ; the carpus produced anteriorly along 

 the inferior margin of the propodos to a sharp tooth ; propodos 

 four times as long as, and not broader than, the carpus, having 

 the superior and inferior margins parallel ; palm slightly crenated 

 anteriorly, not defined ; dactylos almost as long as the projjodos, 

 suddenly curved nearly at right angles close to the base, then 

 straight. Posterior margins of the basa of the three posterior 

 pairs of pcreiopoda serrated. Posterior pair of pleopoda having 

 the rami long, lanceolate, clean. Telson long, double. 



Length ^ths of an inch. 



Hah. Plymouth (C.S.B.); St. Michael's Mount (il/r, Webster); 

 ]?('lfast(7Vio7/!2>wn); J)u'b\m(Klnahan); Moray Frith (Eev.G. Gordon); 

 liuhusia {Bruzelius). 



5, Megamcera Othonis. (Plate XXXIX. fig. 8.) B.M. 



Gammai-us Othonis, Edwards, Ann. cles Sc. Nat. xx. p. 373. pi. 10. f. 11: 

 Hist, des Crust. \\\. p. -W. 



Spence Bale. Brit. Assoc. Report, 1855; Ann. Nut. Hist. F^^h. 1857. 

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



Third segment of the pleon having tlir inf'ero-posterior and postero- 



