220 A COURSE ON ZOOLOGY. 



possessing an external ear. Certain peculiarities of form 

 have gained for the diiferent species the names sea-lion, 

 sea-bear, sea-elephant, etc. The sea-bear of the North 

 Pacific furnishes the fur from which seal-skin garments 

 are made. 



The phocidae, or common hair-seals, are found in all 

 cold seas, and a few species even occur in the tropics. 

 The sea-calf, so called on account of its peculiar cry, is 

 the most common in temperate waters. 



Seals are very intelligent, are easily tamed, and thrive 

 well in captivity. They feed on fish and crabs, and live 



FIG. 149. 



WALRUS. 



in herds near the coasts, where they may be sometimes 

 seen playing on the waves, sometimes resting on the 

 sand-banks. The thick layer of fat that surrounds their 

 bodies enables them to move through the water without 

 exerting any apparent effort to keep afloat. 



The trichecida or walrus, which is sometimes called 

 sea-cow and sea-horse, has two enormous canines in the 



