18gg.] dr. j. e. gray on the skulls of dolphins. 213 



Steno. 



Steno, Gray, Cat. of Seals & Whales, p. 232. 

 The species may he arranged hy their skulls thus. The number 

 refers to the number of the species in the above Catalogue : — 



a. Skull large, solid, the beak compressed, high. Teeth large, 



conical, about two in an inch of the length of the margin of the 

 jato. 



3. Steno frontatus. Beak of the skull short ; the front part 

 thick, high, and blunt. Teeth 24/24, large, two in an inch. 



4. Steno compressus. Beak of the skull elongate, compressed, 

 attenuated in front. Teeth 26/26, large, two in an inch (Zool. 

 E. & T. t. 27). 



Steno rostratus appears to belong to this section. 



b. Skull small, rather spongy. Teeth small, slender, attenuated, 



about four or five in an inch of the length of the margin of the 

 jaw. 



* Beak of the skull elongate, compressed, much attenuated and acute 

 in front. Teeth four in an inch. Sousa. 



4*. Steno capensis. 



4**. Steno lentiginosis. 



The skull of Steno roseiventris, according to the figure, appears 

 to belong to this section of the genus. 



** Beak of the skull short, compressed, much attenuated and acute 

 in front. Teeth five in an inch. Tucuxa. 



7. Steno tucuxi. 



*** Beak of the skull elongate, rather depressed, broad, slightly 

 compressed on the sides. Teeth small, five in an inch. Stenella. 



5. Steno attenuatus. The beak of the skull flattened (Zool. 

 E. & T. t. 28). 



This last section is nearly intermediate between Steno and C/y- 

 mene. 



Delphinus. 



The species referred to Delphinus, Section b, in the ' Catalogue of 

 Seals and Whales,' belong to this genus. The teeth are small and 

 slender, five or six in an inch. 



* Beak of skull twice as long as the brain-case. Teeth ^ or ^. 

 2. Delphinus longirostris, 



