FLESH-EATING MAMMALS OF THE SEA 



75 



The bones are spongy in texture and filled with 

 oil. 



Whales, dolphins and porpoises abound in every 

 sea, and some dolphins inhabit the large rivers of 

 South America and Southern Asia. They vary con- 

 siderably in size, from 4 ft. to 85 ft. in length. 

 Cetaceans, as we have said, are flesh-eaters, but only 



Fig. 21. — Diagnim of a section of the head of Whale-bone 

 Whale, showing position of the whale-bone. Br, brain 

 case ; ho, bone ; s, blow-hole or nostril ; W, whale-bone 

 or balsen ; J, jaws. 



one group of whales, " the killers,'^ prey upon warm- 

 blooded animals. Of these " Orca Gladiator,'' the 

 "grampus,'' is the best known. These whales may 

 attain a length of 30 ft. and are very rapacious, since 

 it is stated that as many as thirteen porpoises and 

 fourteen seals have been found in the stomach of 

 one of them. Dr. Beddard says that the word 



