MAMMALS 



317 



The Ftshlike Mammals [Cetacea) 



The whales, dolphins, and porpoises constitute ilie order, 

 Cetacea. They are acfiatic mammals tvith fishlike bodies. 

 The fore limbs are paddlelike inform while the hind limbs are 

 wanting. The snoid is very long and there is a horizontal 

 caudal fin and often a vertical dorscd fin. The teais are two 

 in number and posterior in positum. The 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 si.xty and seventy feet long. Between the 



