MAMMALS 297 



3. Callorhinus Gray. Dentition 3/2, i/i, 4/4, 2/1; facial portion 

 of skull short: i species. 



C. alascanus Jordan & Clark. Fur seal. Color chestnut brown; 

 length 1,887 mm.; tail 51 mm.; hind foot 548 mm.: Berings Strait to 

 CaUfornia. The animals breed on the Pribilof Islands in June, spending 

 the summer and fall there; in the winter and spring they migrate 

 southward, ranging as far south as southern California. 



Family 2. Phocidae. Hind limbs directed permanently backwards, 

 and of no use in walking; ears absent; fore legs short; claws well devel- 

 oped: about 5 species on the American coasts. 



Key to the American Genera of Phocidae 



ai Teeth 34. 



bi Molars with 2 to 4 cusps each i. Phoca. 



b2 Molars with i cusp each 2. Ealichcerus. 



a2 Teeth 30; snout proboscis-like 3 Cystophora. 



1. Phoca L. Snout narrow and pointed; dentition 3/2, i/i, 4/4, 

 I /i ; forehead convex; incisors conical: cosmopolitan. 



P. vitulina L. Harbor seal. Color yellowish gray, spotted with 

 black; length 1,500 mm.: circumpolar; southward to Lower California 

 and New Jersey; common on the New England coast; ascending rivers; 

 occasionally in Lake Champlain and Lake Ontario. 



P. hispida Schreber. Ringed seal. Color blackish above, with 

 large whitish spots; length 1,500 mm.; body slender; limbs long: circum- 

 polar; southward to Newfoundland. 



P. grosnlandica Erxleben. Harp seal. Color gray, with a black face 

 and a black band across the shoulder and extending along the sides; 

 length 1,500 mm.; body slender; weight 600 to 800 lbs.; circumpolar; 

 southward to Newfoundland and the Magdalen Islands; the basis of 

 the sealing industry in Newfoundland. 



2. HaHchaerus Nilsson. Snout broad and short; teeth 34; molars 

 conical, with a single cusp; incisors conical; claws well developed: i 

 species. 



H. grypus (Fabricius). Gray seal. Color gray, with dark irregular 

 dark spots; length 2,500 mm.; flippers hairy only along the toes: 

 North Atlantic; southward to Nova Scotia. 



3. Cystophora Nilsson. Snout elongated, forming a short proboscis 

 and capable of inflation in the male; dentition 2/1, i/i, 4/4, i/i; 

 incisors conical; molars and premolars small and separated from one 

 another: i species. 



