DELPHINID^. 



209 



pair of tusks in the upper jaw, only one of which 

 is usually developed, projecting as a straight 

 twisted ivory horn of great length ; no dorsal. 



M. monoceros. Fig. 330 ; g^^ n. s. 



Diodon (Less.). Two small teeth in front of the 

 lower jaw, which is projecting and convex ; fore- 

 head low ; one dorsal. 



D. Sowerbyi. Fig. 331 ; g^ n. s. 



330 



 ^ ^^^>^ ^ rii ' 



331 



Hyperoodon (Lacep.). Bottle-nose. Forehead 

 high and round ; muzzle a short beak ; otherwise 

 as Diodon. 



H. bidentatus. Fig. 332 ; ^ ti. s. 



Beluga (Less.). White Whale. Head blunt, un- 

 beaked ; nine teeth on each side in each jaw ; no 

 dorsal. 



B. leucas. Fig. 333 ; -^j^ n. s. 



