THE BASE OF THE SKULL. 



209 



tract, and present.- three rows of foramina for its filaments, and in front a slit-like 

 opening for the nasal branch of the ophthalmic division of the fifth nerve. On 



Groove for superior longitudinal sinus. 



Grooves for anterior meningeal artery. 



Foramen ca?cm. 



Crista galli. 



Sit for nasal nerve. 



Groove for nasal nerve. 



Anterior ethmoidal foramen. 



Orifices fur olfactory nerves. 



Posterior ethmoidal foramen. 



Ethmoidal spine. 



Olfactory grooves. 



Optic foramen.. 



Optic groove. 



Olivary process. 



Anterior clinoid process. 



Middle clinoid process. 



Posterior clinoid process. 



Groove for 6th nerve 



Foramen lacerum medium 



Orifice of .carotid canal 



Depression for Gasserian ganglion, 



Meatus auditorium interims. 



Slit for dura mater. 



Superior petrosal groove. 



Foramen lacerum posterius. 



Anterior condyloid foramen.' 



Aquzductu* restibuli. 



Posterior condyloid foramen. _ 



Mastoid foramen. 

 Posterior meningeal grooves. 



FIG. 172. Base of the skull. Inner or cerebral surface. 



the outer side of each olfactory groove are the internal openings of the anterior and 

 posterior ethmoidal foramina ; the former, situated about the middle of the outer 

 margin of the olfactory groove, transmits the anterior ethmoidal vessels and the 

 nasal nerve, which latter runs in a depression along the surface of the ethmoid to 



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