216 Transactions. — Zootociy. 



having the peduncle longer than the peduncle of the superior. Mandibles 

 having an appendage. Maxillipeds unguiculate, having a small squamous 

 plate to the coxa, basos, and ischium. Gnathopoda uniform, each having 

 the propodos large, with the postero-inferior margin posteriorly produced ; 

 carpus attached to the propodos near the centre of its superior margin ; 

 infero- anterior margin produced along the inferior margin of the propodos. 

 Pereiopoda slender, subequal. Posterior pair of pleopoda biramous. Telson 

 long, narrow, cleft at the apex." 



1. E. cuspidatus, Kroyer, var. antarcticus, G. M. Thomson (Ann. & Mag. 

 N.H., ser. V., vol. VI., p. 4). 



Pleon having the first two segments produced backwards on their 

 postero-dorsal margins into teeth ; fourth segment with a central dorsal 

 sinus. (Two posterior segments of the pereion smooth, not produced into 

 teeth.) Eyes reniform. Superior antennae scarcely half as long as the 

 animal ; peduncle shorter than flagellum ; flagellum minutely articulated, 

 every third articulation produced downwards into a tubercle and furnished 

 with a tuft of cilia ; secondary appendage uni-articulate, almost obsolete. 

 Inferior antennae scarcely as long as the superior, having the peduncle much 

 longer than the peduncle of the superior ; flagellum scarcely longer than the 

 last joint of the peduncle. Both pairs of gnathopoda having the carpus 

 attached near the centre of the superior margin of the propodos, and pro- 

 duced along the inferior margin as far as the palm ; propodos subquadrate ; 

 palm defined by a double row of hairs, which are alternately very short, 

 point of impingement of the dactylos defined by a fascicle of short stout 

 spines. Penultimate pair of pleopoda shorter than the preceding ; ultimate 

 reaching rather beyond the ante-penultimate. Telson long, narrow, grooved 

 longitudinally, and cleft at the apex. 



Length, '35 inches. (The Greenland species is 1*25 inches long.) 

 Genus Aora, Kroyer. 

 (Brit. Mus. Cat. Amphip. Crust., p. 160.) 

 Superior antennae longer than the inferior, and carrying a secondary 

 appendage. Inferior antennae having the peduncle much longer than the 

 flagellum. First pair of gnathopoda much longer than the secofld, and 

 having the meros produced inferiorly into a long tooth. Thii-d pair of 

 pereiopoda shorter than the first two, fourth much longer than the thu-d, 

 fifth much longer than the fourth. Posterior pair of pleopoda biramous. 

 Telson tubular. 



1. A. tyjnca, Kroyer. 



Lalaria longitarsis, Nicolet, Gay's Hist, de Chile. 



Body smooth, eye small, black, and round. Superior antenna nearly 

 as long as animal ; flagellum twice as long as peduncle ; secondary 



