THE SPHENOID BONE 47 



terminating on either side in the optic foramen. Next is the 

 olivary eminence (tuberculum sellos), and next the pituitary 

 fossa, or sella Turcica (Turkish saddle); it is occasionally 

 bounded in front by two middle clinoid processes; behind is 

 a square lamina, the dorsum scllcB or dorsum ephippii (back 

 of saddle), which slopes posteriorly down and back into the 

 basilar groove; this slope is the dims Blumenbachii (Blumen- 

 bach's hill). 



The upper angles of this lamella project over the fossa as 

 the posterior clinoid processes; the sides are grooved for the 

 sixth pair of nerves. The sides of the body present a winding 

 groove curved like the letter /, for the carotid artery in the 

 cavernous sinus. Behind its commencement, at the lower 

 lateral angle of the dorsum sellse, is the petrosal process of the 

 sphenoid, to fit against the apex of the petrous; opposite this, 

 on the other side of the groove, is a tongue-like process, the 

 lingula sphenoidalis. 



The posterior surface is quadrilateral, and united to the 

 basilar process by cartilage in early life, and by bone after the 

 twenty-fifth year. 



The anterior surface is marked in the middle line by the 

 sphenoidal crest, which articulates with the perpendicular 

 plate of the ethmoid. On each side of the crest are a mesial 

 and a lateral part; the lateral shows half-cells, to be completed 

 by the ethmoid and orbital plate of the palatal; the mesial 

 part is smooth, and gives entrance anteriorly into the sphenoidal 

 sinus, and forms part of the roof of the nose. 



The inferior surface presents the rostrum (beak), which 

 continues the sphenoidal crest and fits between the alee of the 

 vomer. 



The sphenoidal turbinate bones (spongy bones, conchce sphenoi- 

 dalcs, bones of Bertin) form a considerable part of the anterior 

 wall of the body of the sphenoid. They are curved and tri- 

 angular, with apex backward. A small portion of them some- 

 times appears on the inner wall of the orbit between the ethmoid, 

 frontal, sphenoid, and palate bones. 



Each lateral surface of the body is mostly occupied by the 

 attachment of the greater wings, except in front a free surface 

 bounds the sphenoidal fissure and forms the hindermost part 

 of the inner wall of the orbit. 



The small or orbital wings (processes of Ingrassias) extend 



