G2 ) PINNIPEDIA. 



the Carnivora, and affinities especially with the Ursidae 

 have been claimed through the Otariidae. 



Fam. Otariidae. Eared seals. This family is characterised by 

 possessing a small pinna, and by the fact that the hind limbs are capable 

 of supporting the body in locomotion, being turned forwards beneath it. 

 They have tolerably long necks, and the nostrils are placed at the end of 

 the snout. The skin of the feet is extended beyond the nails, which are 

 small, being best developed on the three middle digits of the pes. The 

 skull has large post-orbital processes, and an alisphenoid canal. The 

 angle of the lower jaw is markedly inflected. Vertebrae, C7, D15, L5, S4, 

 C9-14. Dentition, i f c \ p % m ll - of which p 2, 3 and 4 are 

 preceded by milk teeth, which are shed a few days after birth. The 

 testicles descend into an external scrotum. They pair and bring forth 

 their young on land, upon which they can move with considerable 

 freedom. They are gregarious and polygamous. Otaria P6r., 9 species, 

 principally Antarctic, but extending to the north in the Pacific ; 0, stelleri, 

 the northern sea-lion, N. Pacific, about 10 feet in length. O. jubata, the 

 Patagonian sea-lion from Patagonia and the Falkland Islands. O. cali- 

 forniana from California. O. ursina, the fur seal of commerce or sea- 

 bear, with a dense soft under-fur, N. Pacific. 0. pusilla, Cape of Good 

 Hope. O. forsteri, Australia. 



Fam. Trichechidae. Walrus or morse, with one genus Trichechus L. 

 They are without external ears, but resemble Otaria in the position of 

 their hind limbs and mode of walking. They are exceedingly bulky 

 animals, and attain to a length of from 10 to 11 feet. The upper canines 

 are modified into projecting tusks. They are covered with short hair, 

 which tends to fall off in old age, and there is a tuft of long bristles on each 

 side of the muzzle. The tail is reduced. The manus has sub-equal digits 

 and small flattened nails ; in the pes the nails of digits 1 and 5 are minute ; 

 those of the others large, compressed and pointed. The soles of the feet 

 are devoid of hair and provided with a rough warty pad. The functional 

 dentition is i <y c \ p and m f ; the molars are conical but wear down 

 to flat crowns ; in the young the teeth are i f c \ m f , some of which 

 are lost early or remain through life concealed beneath the gums. Verte- 

 brae 07, D14, L6, S4, C12. The skull is round with an alisphenoid canal 

 but without postorbital processes. There is a third bronchus on the right 

 side, as in bears, ruminants and cetaceans. The cerebrum is large and 

 richly convoluted, and there is a trace of a posterior cornu. They are 

 gregarious and live on various shell fish, which they dig up with their 

 tusks. They are much hunted for their skins, oil and ivory, and are rapidly 

 diminishing in number and range. The distribution is circumpolar and 

 there are two species, T. obesus in the N. Pacific, and T. rosmarus in the 

 N. Atlantic. 



Fam. Phocidae. Seals. More modified for an aquatic life than the 

 preceding families. The nostrils are dorsal and there is no pinna, and 

 the hind limbs are stretched out backwards on each side of the tail with 

 which they are connected ; they cannot be used in locomotion on land. 

 The fore-limbs are buried to the elbow in the skin but can be used for 

 supporting the body. The outer digits of the pes are longer than the 

 middle. The under side of both manus and pes is hairy. There is no 

 woolly under-fur. Both postorbital processes and alisphenoid canal 



