160 



KEY TO MARINE MAMMALS (Cont.) 



2 Foot-pads present (as on the bottom of a dog's foot); fore-feet 

 not modified into flippers; tail extending beyond out-stretched 

 hind foot; fur medium brown to grayish to blackish, sometimes 

 whitish about muzzle (pups sometimes rufous); underfur (growth of 

 dense velvety fur beneath the long guard hairs) present and 



obvious; guard hair sparse. (SEA OTTER) 15 



2' No foot pads; all feet modified into flippers; tail extremely short 

 or absent; fur gray, tan, brown, white, black, yellow, or combination 

 of these; underfur absent except in fur seals. 



PINNIPEDS (SEALS, SEA LIONS, AND WALRUSES) 3 



3 External ears nearly absent or completely hidden in fur; whiskers 

 beaded (bumpy when slipped through thumb and forefinger) except 

 in Bearded Seal; claws set near ends of flippers or extending 

 beyond them (Fig. 31); five claws on hind foot of most species, 

 although sometimes rudimentary; both surfaces of flippers with fur, 

 babies of most species with woolly fur. PHOCIDS (EARLESS SEALS) 10 



3' External ears present, about 2-3 cm long; whiskers smooth (when 

 slipped between thumb and forefinger); claws set far back from ends 

 of flippers (Fig. 31); distinct claws on all three middle digits 

 of hind feet, claws on outside toes rudimentary (Fig. 31); ventral 

 surface of flippers without fur, dorsal surface without fur except 

 in walrus and Guadalupe fur seal; babies have hair, not woolly fur. 



ODOBENIDS (WALRUS) AND OTARIDS (EARED SEALS AND SEA LIONS) 4 



4 Body form thick; fur scanty; no external tail; external ears without 

 cartilage; tip of tongue rounded; testes internal; first and second 

 upper incisors (present in young only) not grooved on biting edge; 

 all pos team* ne teeth single-rooted and peg-like; canines frequently 

 enlarged to form tusks. WALRUS 



4' Body form elongated; fur abundant except in some rotted individuals; 

 tail present, very short (7-14 cm); external ear with cartilage; tip 

 of tongue notched; testes external; first and second upper incisors 

 with transverse groove on biting edge except in extremely worn teeth; 

 most postcanines with more than one root; no tusks. 



(OTARIDS) 5 



5 Underfur not present; pelage consists of short, stiff hairs; fore- 

 flippers with first digit (same position and analogous to human 

 thumb) longer than second; outermost and innermost digits of hind 

 flippers longer than middle three; short hind flippers, half or 

 less than distance from base of hind flipper to armpit; usually five 

 teeth behind long canines on upper jaw; nose not particularly pointed. 



(SEA LIONS) 6 



