2. LEPXONTX. 11 



** The finst front grinder in each jaw single-rooted, the rest two-rooted. 

 t Lower jaw weak, with an obtttse angle behind ; orbits very large. 



2. LEPTONYX. 



Skull broad, depressed behind; muzzle short, broad; grinders 

 subcompressed, with a small subcentral conical tubercle and a very 

 small posterior one; the lower jaw narrow behind, without any 

 hinder angle ; fore feet clawed. 



Head flattened ; muzzle broad, rather short, roimded ; muffle hairy 

 between and to the edge of the nostrils ; nostrils ovate ; whiskers 

 compressed, slightly waved ; ears, no external conch. Skull slightly 

 depressed, expanded behind ; nose rather short, broad, high above ; 

 orbits rather large ; the petrose portion of the temporal bone convex, 

 hemispherical. 



Cutting-teeth A, conical, rather recurved, those of the upper jaw 

 largest ; the middle in each jaw smaller ; the outer upper much 

 larger. Canines ^j large, conical, curved, rather compressed, upper 

 largest. Grinders |1|, moderate, rather far apart, parallel to the edge 

 of the jaw, compressed, with subcentral, conical, prominent tubercle ; 

 the second, third, and fourth, in the more perfect specimens, with a 

 small conical tubercle on the hinder edge, and a sharp-edged ridge 

 round the inner side of the base ; the front grinder in each jaw . 

 smaller, and with a single conical root, the rest all 2-rooted nearly 

 to the crown. Lower jaw slender, with a short symphysis in front, 

 and narrow, without any angle at the hinder part of the lower edge. 



Fig. 3. 



Leptonyx Weddellii. SkuU, and first and last grinder. 



Fore feet small, elongate, triangular, hairy above and below, with 

 five graduated, distant, marginal claws : Mnd feet moderate ; the 

 two marginal toes largest, rounded at the end ; claws small, rudi- 

 mentary, two middle largest. 



Fur short, adpressed, without any under-fur; hair slender, tapering, 

 slightly flattened. 



The skull of this genus resembles in many respects Cuvier's figure 

 of a skull of Phoca bicolor ; but it diifers from it in all the grinders 



