272 A BOOK OF' WHALES 







is eight or nine feet in length, the nostrils projecting 

 beyond face as a tubular process. 



This dolphin comes from the Cameroon river, and 

 is another example of a purely fresh-water species. 

 It is an exceedingly scarce whale, only one specimen 

 having been seen in as many as ten years. The 

 prolongation of the nostrils is a most remarkable 

 feature, and is amply sufficient to distinguish the 

 species from any other.* Its habits are almost 

 unique by reason of the fact that it is a vegetable 

 feeder. In the stomachs of some other whales 

 vegetable debris has been found ; but in the present 

 species nothing else was found. In accordance with 

 this presumed habit the teeth are not sharply pointed 

 as in S. sinensis. The animal is rather underjawed, 

 and the skin is described as being especially thick. 

 Of the osteology only the skull is known. 



The genus STENO has 20-27 teeth, which are large 

 with furrowed surfaces to their crowns. Vertebrae : 

 C. 7 ; D. 12 (13); L. 15; Ca. 32 (30) = 65, 66. 

 First two vertebrae fused, rest separate. Pterygoids 

 in contact. The formula of the phalanges is : I, 4. 

 II, 8. Ill, 6. IV, 3. V, 3. Dorsal and pectoral fins 

 falcate. Beak distinct. 



Of this genus there are two species, S. perspicillatus 

 and S. restrains. The former lives in the South 

 Atlantic ; the latter is more widely spread. The 



* The blow hole of Balcenoptera has been said to be puffed out during 

 expiration, 



