THE SKULL. 



69 



lesser wing of the sphenoid and orbital plate of the 

 frontal and the great wing of the sphenoid, which, with 

 the squamous portion of the temporal, forms also its 



FIG. 30. FLOOR or THE CRANIUM. 



outer boundary. Behind, the middle fossa is bounded 

 by the anterior surface of the petrous portion of the 

 temporal. The principal foramina are: the anterior 



