CARNIVORA. 593 



Sub-Order Pinnipedia. Seals, Eared Seals, and Walruses. 



These are marine Carnivores, unable to move readily on land, but 

 coming ashore for breeding purposes. They feed for the most part on 

 fish, molluscs, and crustaceans. Absent from the Tropics, they are 

 represented on most of the coasts in Temperate and Arctic zones. Many 

 are markedly gregarious. 



The upper parts of the limbs are included within the skin and 

 general contour of the body. There are five well-developed digits con- 

 nected by a web of skin. In the hind-foot the first and fifth toes are 

 generally stouter and longer than the rest. There are no clavicles. The 

 tail is very short. 



The small milk-teeth are shed or absorbed before or immediately after 

 birth. The incisors are always fewer than f ; 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 pro- 

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



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



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



Family Otariidse — 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 Otaria, 3' ■ ■>' ' _^ supplies the seal-skin of commerce. 



2, I, 4, I 



Family Trichechidse — ^Walruses, intermediate between the OtariidEE- 



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 



, , . . ^ , . 2, I, pm. and m. s 



use are iki%, but the dentition of the young is 



"^'*"' y & 2, I, pm. and m. 4 



There are no external ears. 

 The walrus or morse, Trichechus. 

 Family PhocidiE — 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 f back teeth. There is no external ear. The testes are 

 abdominal. 



The common seal {Phoca), %\W ; the grey seal (Halichcerus), 

 the monk seal (Monachus), the large elephant-seal (MacrorMnus 

 'leoninus). 



Sub-Order Creodonta (extinct). 



In Eocene and early Miocene strata, in Europe and America, there 

 are remains of what seem to be generalised Carnivora, ancestral to the 

 modern types, and apparently related to Insectivora as well. Those 

 included in the sub-order Creodonta have strong canines but no single 



2 P 



