MARINE MAMMALS 



205 



Section IV. — Distribution of Cetaceans 



Adopting the recognized division of the Cetaceans into 

 two sub-orders, Mystacoceti and Odontoceti.. according as to 

 whether their mouths are furnished with baleen ( " whale- 

 bone '") or teeth, we will first consider the True or Whale- 

 bone Whales, which consist of a single family Bahenida, 

 usually divided into rive genera: BaJUena, Neobal&na, 

 Rhachianectes, Megaptera, and Balamoptera. Of these, 



Fig. 47.— The Speem Whale. 



(Ph'j$eter macroceplalui.) 



[Flower and Lyd. Mamm., p. 249.] 



Balama (Fig. 46, p. 204). Megaptera, and Balamoptera are 



almost cosmopolitan — species of them, whether distinct or 

 not is at present more or less uncertain, being met with in 

 nearly every part of the ocean. But Bhachianectes has 

 as yet been ascertained to occur only in the Northern 

 Pacific, and Neobalama in the South Polar Ocean, so that 

 we have in these cases two well-marked local types to 

 deal with. 



The Toothed Whales < Odontoceti) are more diversiried 

 than the preceding group, and are usually held to em- 

 brace at least four existing families besides extinct forms. 



