236 



THE SKULL. 



[CHAP. 



not in the least overlapped by it, as in the Dog. The 

 occipital plane is vertical, or even inclining forwards above. 

 The tentorial plane is nearly horizontal. The olfactory 

 fossa, though smaller in vertical extent than that of the Dog, 

 is more produced anteriorly. Thus in form, as well as in 

 relative size, the cerebral cavity is far more reptilian than 

 that of the Dog. The basicranial axis is very straight, and 



FK;. 70, Section of the skull of the Thylacine (TJiylacinus cynocephalus), \. 

 MT maxilloturbinal ; ET ethmoturbinal ; ME ossified portion of mesethmoid ; 

 /> frontal ; Pa. parietal ; SO supraoccipital ; EjcO cxoccipital ; Per periotic ; 

 BO basioccipital ; S<] squamosal ; AS alisphenoid ; TiS basisphenoid : OS orbito- 

 sphenoid ; 1'S presphenoid : Pt pterygoid ; /V palatine; f'fvomer; M.\ maxilla ; 

 PMx premaxilla; ai condyle of mandible ; a angular process. 



is continued forwards in the same line by the basifacial 

 axis. The pituitary fossa forms no distinct impression, and 

 there are no posterior clinoid processes. The ossified 

 portion of the mesethmoid (AfE) is extensive, and termi- 

 nates anteriorly in a nearly vertical line. The vomer ( Vo) 

 is very shallow from above downwards. The turbinal 



