HEAD. 69 



apex forms the inferior extremity of the cells. Devel- 

 opment: three nuclei of ossification. 



Sphenoid. — Division : Body and wings, two faces 

 and four borders. The external surface, continned 

 with the basilar process, shows the vidian fissure, tlie 

 vidian canal, the sub-sphenoidal canals, the orbital 

 hiatus, a surface for the orbital cavity. The internal 

 face shows the crista-galli process, the optic fossa, tlie 

 pituitary fossa, some digital impressions, mastoid fossa^ 

 two fissures — one internal cavernous, and one external, 

 both opening in the three super-sphenoidal canals form- 

 ing the foramen lacerum orbitale,the foramen rotunduni 

 magnum and the foramen patheticum. The borders 

 are : superior, articulated wdth tlie occipital, and pre- 

 senting three notches — one internal, the carotid, contin- 

 uous with the carotid fossa, one external, for the infer- 

 ior maxillary nerve, and one outward, for the middle 

 meningeal artery ; an inferior border assists to form tlie 

 sphenoidal sinus; two lateral borders, articulated with 

 the frontal. Development : two nuclei of ossification. 



Temporal. — Division : Squamous and tuberous por- 

 tions. 



Squamous. — Two faces and a circumference. The 

 external face shows the zygomatic process with a base 

 having a condyle and a glenoid cavity, an external and 

 an internal face, and an apex ; the internal face has a 



