COMMON BEAKED-WHALE. 421 



CETACEA. PEYSETERID^. 



{flDONTOOETI.) 



Genus Hyperoodon (Lac6pede, 1804). 



Generic Character. — Front rounded, convex; a distinct beak; mouth small. 

 Flippers small, dorsal fin low and very far back. Skull with two great bony 

 crests on the maxillaries, nearly or quite as high as the occipital portion. No 

 teeth in the upper jaw, those in the mandible two or three in number, small 

 and concealed by the gum. Cervical vertebrae united. 



COMMON BEAKED-WHALE. 



Hyperoodon rostratus (Chemnitz). 



Specific Character. — Nearly black, paler on belly. Teeth i. Skull with 

 the maxillary crests narrow, widely separated, and not higher than the 

 occipital portion. 



Balana rostrata, Chemnitz, Berlin Besch., iv., 183 (1778). 



ffyperoodon hutzJcopf, Lao^pJide, Hist. Nat. des Cet., 319 (1804). 

 Delphmus hidens, Tcbton, Brit. Fauna (1807). 



Heteroodon hyperoodon, Lesson, Man., 419 (1827). 



The remarkable group of Cetaceans known as Ziphioid 

 Whales hold in many respects an intermediate position 

 between the Cachelots (along with which they form the 

 family Physeteridm), and the Dolphins and Porpoises. 

 Few species of this family are now known to exist, and 

 with one exception they all appear to be very rare animals, 

 but they were abundant in the later geological epochs, 

 and especially at the period of the Crag formations. 

 These facts, in the words of Prof. Flower's recent memoir 



