LEUCOTHOE. 269 



AMPHIPODA. GAMMA RIDES. 



NATATORIA. 



Genus— LEUCOTHOE. 



Leucothoe. Leach, Edin. Ency. vii. p. 403. Trans. Linn. Soc. xi. p. 358. 



Suppl. Ent. Brit. i. p. 425. Samouelle, Ent. Comp. 



p. 103. Edwards, Hist, des Crust, t. iii. p. 56. Ann. des 



Sc. Nat. t. XX. p. 380. Desmarest, Consid. Crust, p. 2C3. 



White, Hist. Brit. Crust, p. 188. Cat. Crust. Brit. Mus. 



1847. Cat. Brit. Crust. Brit. Mus. 1850. Spence Bate, 



Cat. Ampli. Brit. Mus. p. 156. Ann. Nat. Hist. 2 ser. 



vol. xix. p. 146, 1857 (not of Kroyer or Dana). 

 Lycesla. Savignf, Mem. sur les Animaux sans Vert. vol. i. p. 109. 



EgyiJt. Crust, pi. ii. f. 2. 



Generic character. Antennae simple, nearly equal. Mandibles, 

 with a very minute palpiform appendage. Gnathopoda having 

 the carpi inferiorly produced to at least half the length of 

 the propoda. Propodos in the first pair slender, in second broad. 

 Middle pair of pleopoda shortest. Telson simple. 



In this genus the body of the animal is long and com- 

 pressed. The antennae are simple, and nearly of the 

 same length. The footjaws are subpediform, and un- 

 guiculate — that is, they have not the large squamiform 

 plates attached to some of the joints which are present 

 in many other genera, but have a stronger resemblance 

 to the condition of simple legs, and terminate with a 

 sharp point at the extremity of the finger. The mandi- 

 bles are furnished with an appendage. The first pair of 

 legs have the wrists produced along the inferior margin 

 of the hand as far as its distal extremity, the terminal 

 half being free ; in the second pair the wrist is produced 

 along the inferior margin of the hand to half its length ; 

 but in the first pair the hand is narrow, whereas it is 



