206 



THE SKULL. 



[chap. 



have a large perforation in front of the margin of the orbit. 



There are no postorbital pro- 

 cesses to the frontals, or any 

 other demarcation between the 

 orbits and the temporal fossa. 

 The palate is extremely 

 elongated, and produced back- 

 wards as far as the level of 

 the external auditory meatus 

 by the meeting in the middle 

 line of the largely-developed 

 pterygoids (Ft). The glenoid 

 fossa is a shallow oval facet, 

 with its long diameter from 

 before backwards. 



The periotic, tympanic, and 

 squamosal are ankylosed toge- 

 ther. A small mastoid portion 

 appears on the outer side of 

 the skull, forming a roughened 

 surface between the squamosal 

 and the exoccipital. The tym- 

 panic (Ty) is somewhat trian- 

 gular in form, slightly bullate, 

 and not prolonged into an au- 

 ditory meatus. In front of the 

 tympanic cavity, and freely 

 communicating with it, is a 

 FMx?$$jf considerable air sinus, formed 



Fig 65.— Under-surface of the cranium between the pterygoid (Pt) and 

 of the Great Anteatei {Myrmeco/>haga 



jubaia), \. so supraoccipnai ; bo basi- the ahsphenoid (^4.5j,and caus- 



occipital ; ExO exoccipital ; Ty tym- . . . . , 



panic ; Pt pterygoid ; Sq. squamosal ; ing an OVal prominence 111 the 



A S ahsphenoid ; OS orbitosphenoid ; ., c , , 



At malar ; L lachrymal ; PI palatine; Side 01 the palate. 



Atx maxilla ; PMx premaxilla. 



