MAMMALS 



317 



The Fishlike Mammals (Cetacea) 



The whales, dolphins, and porpoises constitute the order, 

 Cetacea. They are aquatic mammals with fishlike bodies. 

 The fore litiihs are paddlelike inform while the hind limbs are 

 wanting. The snout is very long and there is a hrmzontal 

 caudal fin and often a verticcd dorsal fin. The teats are two 

 in ruuynber and postenor in position. Th,e skin is devoid of 

 hair. 



Whales. — There are two distinct groups of whales, viz. 

 those possessing strong functional teeth, — hence called 

 the toothed whales; and those possessing no teeth in the 



Fig. 209. 



.Jaws of a whalebone whale, showing the baleen. 



adult stage, but having plates of " baleen " or " whale- 

 bone " which take the place of teeth, — hence known as the 

 whalebone whales (Fig. 209). The sperm whale, found 

 largely in the .southern Pacific, southern Atlantic, and 

 Indian oceans, is an example of the toothed whales. The 

 males are often sixty and scveulj- feet long. Between the 



