454 

 2502. The right ramus of the lower jaw of a Dolphin (Delphinus). 



Number of alveoli : 22. 



Hunterian. 



2503. The skeleton of the White-nosed Dolphin (Delphinus leucoramphus). 



Number of alveoli : J j^j= 160. The cervical vertebrae have coalesced : the other verte- 

 bras are 5 1 in number, thirteen of which support moveable ribs : the thirty-eighth vertebra 

 is the first to the centrum of which a haemapophysis is attached. 



Mus. Brookes. 



2504. The lower jaw of a Dolphin (Delphinus). 



The tip of the jaw appears to have been cut off. The number of alveoli is : 40 39. 

 Hunterian. 



Subgenus Delphinapterus. 



2505. The skull of the Beluga or White Dolphin (Delphinus leucas). 

 Number of alveoli : . 



Mm. Brookes. 



2506. The right moiety of a vertically bisected cranium of the Beluga (Delphinus 

 leucas). 



It shows the large size of the prefrontal bones, which have coalesced with the vomer, and 

 ascend into view at the back part of the nostrils, where they coalesce with the frontals. The 

 small nasal bones are wedged into an interspace between them and the frontals at the summit 

 of the nasal apertures. 



Hunterian. 



2507. The lower jaw of the Beluga (Delphinus leucas). 



The outer wall of the alveoli of the teeth has been removed from the right ramus : the 

 exposed crowns of the teeth are more obtuse than that of their implanted fangs : the two 

 anterior teeth are procumbent. Number of alveoli : 9 9. 



Hunterian. 



2508. The right ramus of the lower jaw of the Beluga, Avithout the teeth. 

 Number of alveoli : 8. 



Mm. Brit. 



