1901.] 



DOLPHIN FROM BORNEO. 



89 



The skull (text-fig. 11) at once shows that the specimen belongs 

 to the Sotalia-Steno group of Dolphins, to which comparison may 

 accordingl}^ be restricted. The pterj-goids are widely separated 

 from one another in the middle line ; and the teeth, which are of 

 medium size, smooth, and antero-posteriorly compressed, number 

 36 in the upper, and 34 iu the lower jaw. Unfortunately the 

 skeleton is somewhat incomplete posteriorly, so that the total 

 number of vertebrae cannot be ascertained. There are, however, 

 30 in the precaudal series. 



Lower view (A) and lateral view (B) of the skull of Soialla bonteensis. 

 PL Pterygoid. 



As regards the distinction between Steno and Sotalia, Messrs. 

 Flower^ and True' inchided all the forms with divided pterygoids 

 in the latter, and those with conjoint pterygoids in the former. 

 Mr. Blanford ^ however, has transferred the three Indian species 

 S. pluinheus, S. perniger, and S. lentiginosus from Sotalia to Ste)io, 



^ List ofCetacea in Brit. Mus. pp. 31 & 32 (1885). 

 2 jBuii. U. S. Nat. Mus. No. 36, pp. 153 & 15(5 (1889). 

 ^ Fauna of Brit. ladia : Mammalia, pp. 582-585. 



