HAIR SEALS OR SEA DOGS. 209 



both families, are called Fur Seals ; and those which are 

 entirely devoid of this under fur, or possess it only in a 

 limited degree, are known as Hair Seals. Not all the 

 Otariidae are Fur Seals; but all the Phocidae are Hair 

 Seals, although the cubs of some of the species of the 

 latter family are called Wool Seals, until they lose the 

 soft woolly white coat with which they are born. The 

 time of shedding this coat varies in different species. The 

 cubs of the Common Seal take to the water and change 

 their coat within a few hours of their birth, while the 

 young Greenland Seals do not go into the water or shed 

 their fur, until they are from four to six weeks old. Seals 

 seldom produce more than one cub in a year, and never 

 more than a pair. They subsist entirely upon fish, crus- 

 taceans and mollusks, and can sleep as well floating on 

 their backs on the sea, as upon the ice floes or the land. 



TRUE SEALS (Phocidae) 



True Seals occur along the shores of the temperate and 

 colder portions of the globe, but the greater number are 

 found on the Northern Hemisphere. The members of 

 this family have no trace of external ears, and the front 

 limbs are always smaller than the hinder. The under 

 surfaces of both front and hind feet are well covered with 

 hair, and in most cases all the digits are furnished with 

 well-developd claws. The hind feet are incapable of the 

 great power of expansion, and want the long flaps of skin 

 at the extremities characterizing those of the Eared Seals. 

 There is but little difference in size between the males and 

 females of this family, and none of the various species are 

 Fur Seals. True Seals are with few exceptions gregar- 

 ious, gentle and submissive, offering no resistance when 

 attacked by man. They have strongly developed social 

 instincts, and display an extraordinary affection for their 

 young, who generally remain on the land for the first few 

 weeks of their existence, and who, strange as it may seem, 

 take reluctantly to the water, and have to be taught the 

 art of swimming by their parents; but the cubs of the 

 Common Seal are a marked exception to this rule. True 

 Seals are more specialized for an aquatic life than the 



