THE CRANIUM. 135 



elongated backwards into a horizontal angle, called the spinous 

 process, which is fixed between the petrous and squamous portions 

 of the temporal bone. From the point of the spinous process pro- 

 jects downwards the styloid process. The great wing presents 

 a triangular serrated surface above, at its outer end, by which 

 it articulates with the osfrontis; just below this, in front, is a short 

 serrated edge, by which it articulates with the malar bone; and 

 externally, is a semicircular serrated edge, by which it articulates 

 with the squamous portion of the temporal bone. The tip of the 

 large wing generally articulates also with the parietal bone. 



Between the apophysis of Ingrassias and the greater wing is 

 the foramen sphenoidale, called also foramen lacerum superius of 

 the orbit. It is broad near the body of the bone, and becomes a 

 mere slit at the extremity of the little wing. Through it pass 

 the third, fourth, the first branch of the fifth, and the sixth pair 

 of nerves. Two lines below the base of this hole is the foramen 

 rotundum, for transmitting the second branch of the fifth pair of 

 nerves. Eight lines, or thereabouts, behind the foramen rotun- 

 dum, is the foramen ovale, for transmitting the third branch of 

 the fifth pair of nerves. Two lines behind the foramen ovale is 

 the foramen spinaie, for transmitting the middle artery of the 

 dura mater. In the under part of the bone, and passing through 

 the root of the pterygoid processes, is the foramen pterygoideum, 

 for transmitting the pterygoid nerve; it being a recurrent branch 

 of the second branch of the fifth pair of nerves. 



The sphenoid* bone articulates above and in front with the 

 vomer, the frontal, ethtnoidal, malar, and parietal bones : late- 

 rally with the temporal, behind with the occipital, and by its 

 pterygoid processes with the palate bones. 



6. Ethmoid Bone, (Os Elhmoides, Ethmoide.) 



This bone is placed between the orbitar processes of the os 

 frontis, and, as has been stated, fills the vacuity between them. 

 It is cuboidal, extremely cellular, and light. 



The horizontal portion between the orbitar processes is the 



* This bone is, by some anatomists, described in common with the os occipitis, 

 & the osbasilare, in consequence of their early junction into a single piece. 



