7. DIOPLOBON. 355 



arc sufficient to clearly characterize the species. Unfortunately the 

 lust-mentioned peculiarity is scarcely sufficiently indicated in the 

 figure. 



The edges of the front lower teeth are absorbed or worn away by 

 the friction of the u})pur jaw against them, the vomer forming a 

 largo fusiform prominence on the upper surface of the base of the 

 beak, in front of the blowers, between the narrowed part of the 

 elongate, slender intermaxillaries, which are enlarged and thickened 

 beliind, forming the outer sides of the blowers. 



In this respect it agrees with the figure of the skull of Dioplodon 

 SecheUensis from the Indian Seas, given by M. Gervais (Zool. et 

 Paleont. Frang. t. 40. f. 3-6) ; but the vomer is more prominent in 

 the Cape species. The Cape species has the slender, elongated, 

 tapering lower jaws, and a very much longer beak to the skuU, like 

 that of D. micropterus of Havre (Gervais, I. c. t. 49. f. 1). 



I was informed, in 1864, that two Dolphins which agreed with 

 M. F. Cuvier's description and figure oi Belpliinorhynchus micropterus 

 had been taken on the coast of South Africa, and that the skulls were 

 then in the possession of a surgeon at the Cape. There is also a 

 third skuU, in a scmifossil state, in the colony. 



7. DIOPLODON. 



Lower jaw broad behind, suddenly narrowed in front before the 

 teeth. Teeth in the side of the lower jaw (of male ?), large, com- 

 pressed, considerably behind the back edge of the rather short 

 symphysis. 



Animal unknown. 



Dioplodon (part), Gervais, Zool. ct PaUont. Fratiq. 



Dioplddon, Gray, Proc. Zool. Soc. 1863, 200. 



Mesiodon (part), Duvernoy, Ami. Sci. Nat. xv. 58. t. 2. f. 4. 



•» 

 Dioplodon SecheUensis. The Seychclle Ziphius. hJ ^/. 



/■/^ 



Ziphius do S^chelles {M. Ic Due, 18-39), Mus. Paris. 



Ziphius Sechollensis, Gray, Zool. E. *y T. 28. t. 6. f. 1, 2 (lower jaw). 



Ziphius di'usirostris, Bluinv. Mtts. Paris. / 2- J' 



Mt'scKUi)dt)n densirostris, Di/vernoy, Ann. Sci, Nat. 1851, xv. 58. t. 2. / 



f. 4 (not D. densirostris, Desm.). 

 Dioplodon densirostris, Gervais, Zool. et Paleont. Frauq. t. 40. f. 3-6 



(skidl) ; Gray, Proc. Zool. Soc. 1863, 200. 



Inhab. Seychelles. Skidl in Mus. Paris. 



The skuU is very like that of Ziphius, but the nose-bones are 

 thicker, heavier, and higher. The teeth in the middle of the lower 

 jaw, as in the male Z. Soiuerhiensis, but larger and conii)ressed. The 

 hinder part of the lower jaw is very broad, the fi'ont half much nar- 

 rower and bent down in an arched manner. 



2 A 2 



