THE COMMON P0EP0I8E. 



141 



their own order ; and their teeth are modified accord- 

 ingly. They are divided into the following- families : — 

 1, DeJphinidcB, Dolphins, Grampuses, Narwhals, &c. 

 2. Catodonfidce, Cachalots, or Spermaceti Whales. 3, 

 JBalcenidcc, Rorquals and Blubber Whales, 



Family— DELPHINIDiE (Dolphins, Porpoises, &c.). 



The Common Porpoise (Phocmia cotnmum's). 



In the genus Phocsena the snout in the living animal is 

 not produced as in the dolphin ; but in other respects 

 the characters are the same. The teeth are numerous, 

 compressed, rounded, and interlock when the jaws are 

 closed, and are well fitted for snapping at and retaining 

 the slippery prey. (Fig. 93.) A dorsal fin is present. 

 There are several species. 



Teeth of Porpoise. 



The common porpoise is active, fleet, and voracious ; 

 it frequents, in troops, the baj'-s and inlets of our coast, 

 and es])ecially the mouths of rivers, not un frequently 

 advancing to a considerable distance up their stream. 

 (Fig. 94.) In such places it is often taken in nets by 

 the fishermen, becoming entrapped while eagerly pursu- 



