1 64 



THE SKULL. 



[CHAP. 



alisphenoid canal for the passage of the internal maxillary 

 artery. 



The base of the cranium is long and narrow. The 

 glenoid surface for the articulation of the mandible is 

 gready extended transversely, concave from side to side, 

 convex from before backwards in front, and hollow behind, 

 and is bounded posteriorly, at its inner part, by a prominent 

 postglenoid process (Fig. 56,/^). 



Fig. 50. — Side view of the posterior part of the skull of a Horse, \. i^r frontal (the 

 line points to the postorbital process) ; Sq squamosal ; Pa parietal ; SO supra- 

 occipital ; ExO exoccipital : oc occipital condjle ; pp paroccipiial process ; Per 

 mastoid portion of peri jtic ; // post-tympanic process of squamosal ; th tympano- 

 hyal ; Ty tj'mpanic ; j>g postglenoid process of squamosal ; As alisphenoid (ihe 

 line points lo the plate of the bone which bridges over the alisphenoid canal) ; Ma 

 malar. 



The squamosal {Sq) enters considerably into the forma- 

 tion of the temporal fossa, and besides sending the zygo- 

 matic process forwards, it sends down behind the meatus 

 auditorius a post-tympanic process (//), which aids to 

 hold in place the otherwise loose tympano-periotic bone. 

 Behind this the exoccipital gives off a very long paroccipital 

 process (//). 



