86 A BOOK OF WHALES 



The "seals" unquestionably form a subdivision of 

 the Carnivora to which on account of the fin-like 

 character of the fore limbs the name of Pinnipedia 

 has been given ; further than this, it is possible to 

 place them nearer to the Bear division of the land 

 Carnivora than to the other groups. 



The effects of a seafaring life are more plainly seen 

 in the true seals than in the Walrus or the Sea-lions. 

 The latter group in fact is a stage leading towards the 

 more completely aquatic seal. 



In the true seals (Phocidae) the form is more fish- 

 like ; the nostrils have come to lie upon the top of 

 the head instead of terminally ; the external ears 

 have completely vanished, the auditory organ being 

 marked externally by a hole only ; the hind limbs are 

 quite useless for progression on land, being quite 

 bound up by integuments with the tail. The sea- 

 lions can move with some rapidity upon dry land, 

 since the hind limbs have not so nearly lost their 

 original functions. The external ears are present but 

 much reduced ; they vary, moreover, in the degree 

 of reduction, being much larger in the Cape Sea-lion, 

 Otaria pus ilia, than in the beast of Patagonia, 

 Otaria jubata. 



In these external characters there are certain 

 obvious resemblances to whales the fish-like form, 

 the disappearance of the conch of the ear, the form 

 of the fin, which is even falcate in form in both 

 groups of aquatic mammals ; the removal (in the seals) 

 of the nostrils to the top of the skull, though not to 

 a point so far back as in the whales ; these are 



