KEY TO LAND MAMMALS OF NORTHEASTERN NORTH AMERICA 121 



Family Phocidae Earless seals 



Hind feet directed permanently hackward ; no etxernal ears ; no tusks. 

 ^Ph6oidae; genus P h o c a ) 



The family Phocidae contains a dozen or more genera distributed 

 on practically all sea coasts. Four occur in North America, all of which 

 are represented within our limits. 



GENERA OP PHOCIDAE 



Teeth 30; snout of male developed into a conspicuous "hood" 



(subfamily Cystophorinae) Cystophora 



Teeth 34; snout not specially developed (subfamily Phocinae) 



Braincase forming less than one third of length of skull Halichoerus 



Braincase forming nearly one half of length of skull 



Cheek teeth large and strong; forehead high, arched Phoc a 



Cheek teeth small and weak; forehead low, flat Erignathus 



Genus Cystophora Nilsson 



1820 C y s t ophora Nilsson, Skand. fauna. 1:382. Type .C y s t oph o r a 

 borealis Nilsson=P hoca cristata Erxleben. 

 Teeth 30 {only two front teeth in lower jaw) ; muzzle elongated, that of male 

 capable of inflation. (Cyst6phora; Gk., bladder-bearer) 



The genus Cystophora is peculiar to the coasts and islands of 

 the North Atlantic. Only one species is known. 



Cystophora cristata (Erxleben) Hooded seal 



YVlt [Phoc a] cristata Erxleben, Syst. regn. anim. 1:590. (Greenland) 



1837 Cystophora cristata Nilsson, Kongl. Vet. akad. Handl. Stock- 

 holm. 



1880 Cystophora cristata Allen, History of North American pinnipeds, 

 p. 724. 



1884 Cystophora cristata Merriam, Science. 5 Dec. 1884. 4 : 514. 

 Bluish black, lighter on sides and belly ; back thickly sprinkled with irregular 



whitish spots. Total length 2450 (7 ft) to 2800 (8 ft). (cristfJta; Lat., 



crested) 



The hooded seal occurs on the northern coasts of western Europe 

 and eastern North America. In the latter country its southward range 

 extends about to Nova Scotia, though stragglers have been taken as far 

 south as Long Island. 



Genus Halichoerus Nilsson 



1820 Hali choerus Nilsson, Faun. Skand. 1:377. Type Halichoerus 

 g r i s e u s Nilsson=P hoca grypus Fabricius. 



Teeth 84 (four front teeth in lower jaw) ; braincase very small, forming less 

 than one third length of skull. (Halichoerus; Gk., sea pig) 



The genus Halichoerus is peculiar to the coasts and islands of 

 the North Atlantic. Only one species is known. 



