DOLPHINS 265 



members of the genus by the amount of ossification 

 in the mesethmoid, and by its appearance on the 

 dorsal surface of the skull. The species is from the 

 Indian Ocean and the tropical Pacific. 



The two next species are British, and can be easily 

 separated. 



Lagenorhynchus albirostris, Gray,* has a length 

 of 9 feet. Teeth, 26. Vertebrae: C. 7 ; D. 15 (16) ; 

 L. 23 (24) ; Ca. 43 (45) = 88 (92). Five ribs, reach 

 sternum ; 6 or 7 two-headed. Pterygoids in contact. 



This species occurs on our own coasts, and is, so 

 far as is known, purely a northern species. It 

 appears that the winter is passed in the more tem- 

 perate regions of the north, and the summer in the 

 arctic regions. The dolphin goes about in large 

 bands, and is a fish-eater in the main. 



Lagenorhynchus acuhis, Grayt ( = Delphinus csch- 

 richtii, Schlegel ; D. leucopleurus, Rasch). Length, 

 8 feet. Dorsal fin high. Beak small. Teeth, 

 35-37. Vertebrae: C. 7; D. (14), 15; L. 18-22; 

 Ca. 38-41=78-82. Pterygoids in contact. 



This also is a northern species. It occurs in vast 

 herds of as many as fifteen hundred individuals on 

 the coast of Norway ; it is then in pursuit of the 

 herrings. A skeleton in the British Museum has the 



&> v 



* Ann. Mag. Nat. Hist., 1846, xvii., p. 84. 

 t In BROOKE'S Cat. Mus., 1828. 



