PHOCin.K 



60 1 



fifth not greatly exceeding the others in length, and with the 

 interdigital membrane not extending beyond the toes. 



Hcdichosrus. 1 — Dentition: i -f, c \, j> .{,/// j : total 34. Crowns 

 of molars large, -simple, conical, recurved, slightly compressed, 



V Y V 



275.— Upper permanent and deciduous dentition ofthe Greenland Seal (PJwca gro nlandiea). 

 The first and second deciduous incisors arc already absorbed. 



with sharp anterior and posterior edges, but without accessory 

 cusps, except sometimes in the two hinder ones of the lower jaw. 

 With the exception of the last one or two in the upper jaw and 

 the last in the lower jaw they are all uniradicular. Vertebras : C 

 7, D 15, L 5, S 4, C 14. 



One species, H. grypus, the Gray Seal of the coasts of 

 Scandinavia and the British Isles (see page 604.) 



Phoca. 2 — Dental formula as the last. Teeth smaller and more 

 pointed. Molars (Figs. 275 and 276) with two roots (except the first 

 in each jaw) ; and 

 their crowns with 

 accessory cusps. 

 Vertebrae : C 7, D 

 15, L 5, S 4, C 

 12-15. Head 



round and short. 

 Fore feet short, 

 with five very 

 strong, subcom- 

 pressed, slightly 

 curved, rather 

 sharp claws, sub- 

 equal in length. 

 On the hind feet the claws much narrower and less curved. The 

 species of this genus are widely distributed throughout the northern 

 hemisphere, and include P. barbafa, the Bearded Seal ; P. grcen- 

 landica, the Greenland Seal ; P. vittdina, the Common Seal (Fig. 

 277); and P. hispida, the Ringed Seal of the North Atlantic; 

 /'. caspica, from the Caspian and Aral Seas ; and P. sibirica, from 

 Lake Baikal. 



1 Xilsson, Faun. Scandinav. vol. i. p. 377 (1820). 

 2 Linn. Syst. Nat. 12th ed. vol. i. p. 55 (1766). 



Fig. 270. — Skull of Common Seal, showing form of teeth. 



