SKELETON OF ARTIODACTYLA. 



469 



extended bony palate below the level of the basis cranh, 1-9. The 

 petrotympanic bulla, id, is large, prominent, and subcompressed. 

 In the interior of the cranium the rhinencephalic compartment, h, 

 is large and well defined. 



The skull of the Babyroussa {^Sus Babi/russa), as compared 

 with that of Sus Scrofa and Sus larvatus, shows a broader and 

 lower occiput ; the mastoids are larger ; the temporal fossae more 

 approximated on the upper part of the cranium ; the bony palate 

 is more produced beyond the last molars. The mastoids show a 



316 



317 



Skull of Wart-hog (PhacochcBrics). 



M<andible of Wart-hog. 



pneumatic cellular structure, and become confluent with the tym- 

 panic and squamosal, not with the petrosal. This bony capsule of 

 the acoustic organ retains its primitive individuality, as such, and 

 may be detached from the surrounding bones forming the oto- 

 crane : neither paroccipital nor mastoid are dismemberments 

 thereof, as misinterpreters of developmental phenomena allege. 

 There is no ossified prenasal. In the maxillary the long sockets 

 of the canine tusks bend upward ; the naso-maxillary part of the 

 cranium being slightly compressed between them. A remarkable 

 peculiarity is also presented by the fossa? at the inner side of the 

 base of the pterygoids, which lead to sinuses communicating on 

 one or both sides with the sphenoidal sinus. The air-cells extend 

 from the nose to the occiput. 



In the Wart-hog {Phacochairus ^liani, fig. 316), the fronto- 

 parietal region is broad and flat, except transversely, where it is 

 rendered concave, as in the Hippopotamus, by the orbits being 

 raised above its level : those cavities, e, are placed farther back 

 than in the other Suidce, and are partly defended by a post-orbital 

 process of the malar. The paroccipital processes are long and 



