PINNIPEDIA. 



721 



birth. The incisors are always fewer than - ; there are no carnassials ; 



the back teeth have pointed cusps, often sloping slightly backwards. 



The brain is large and well convoluted. The eyes are large and 

 prominent, with a flat cornea. The external ear is small or absent. 



The caecum is very short. The kidneys are divided into lobules. 

 The mammse are two or four in number, and lie on the abdomen. 



Family Otariidae — Eared or fur-seals, connecting the Pinnipeds with 

 the Fissipeds. The hind-feet can be turned forward and used on 

 land in the usual fashion. The palms and soles are naked. 

 There is a small external ear. The testes lie in an external 

 scrotum. 



The sea-lion Olaria, 



Pacific and S. Temperate seas. 



Family Trichechidse — Walruses, intermediate between the Otariidse 



Fig. 319. — The common seal. 



and the seals. The hind-feet can be turned forwards and "used 

 on land. The upper canines form large tusks ; the other teeth 

 are small, single rooted, and apt to fall out ; those generally in 



use are 1121 but the dentition of the foetus is £&. 

 0130' 3131 



The jaw seems relatively short, an adaptation perhaps to mussel- 

 crushing instead of fish-catching. 

 There are no external ears. 

 The walrus or morse, Trichechus (Arctic). 

 Family Phocidse — Seals, the most specialised Pinnipeds. The hind- 

 limbs are stretched out behind, and the strange jumping move- 

 ments on land are effected by the trunk, sometimes helped by 

 the fore-limbs. The palms and soles are hairy. There are well- 

 developed canines ; the upper incisors have pointed crowns ; there 



are - back teeth. There is no external ear. The testes are 



5 

 abdominal. 



46 



