20 PRACTICAL ANATOMY. 



THE TEMPORAL BONES. 



The temporal belong to the class of irregular bones. 

 They are situated at the sides and base of the skull, and 

 present three portions, the squamous, mastoid, and 

 petrous. The squamous portion is a thin plate of bone, 

 which presents for examination an inner and outer sur- 

 face and a border. At its superior part the border is 

 convex, beveled at the expense of its inner surface, and 

 articulates with the inferior border of the parietal. The 



FIG. 8. LEFT TEMPORAL BONE, OUTER SURFACE. 



anterior and inferior part of the border articulates with 

 the sphenoid. The squamous portion is translucent ; it 

 is composed of dense bone, and contains no diploic 

 structure. Its outer surface, smooth and slightly con- 

 vex, presents some shallow grooves for the deep temporal 

 arteries. It assists in forming the temporal fossa, which 

 is limited posteriorly by the temporal ridge, separating 

 ,the squamous from the mastoid portion. Projecting 

 horizontally forward from the lower and posterior part 

 of the squamous portion is the zygomatic process, the 



