2o6 



THE SKULL. 



[chap 



have a large perforation in fr 

 so 



Fig 65. — Under-surface of the cranium 

 of the Great Anteatei {Myrnietophnga 

 jubatd), \. ^(^supraoccipitdl; ^Oba-i- 

 occipital ; ExO exoccipital ; Ty tym- 

 panic ; Pt pterygoid : Sq. squamosal ; 

 ,-i^ alisphenoid ; OS orbitosphenoid ; 

 M malar ; L lachrymal ; PI palatine; 

 Mx maxilla ; PMx premaxilla. 



ont 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 {Pt). 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 

 considerable air sinus, formed 

 between the pterygoid {Pt) and 

 the alisphenoid (^.5'),and caus- 

 ing an oval prominence in the 

 side of the palate. 



