16 HUMAN ANATOMY. 



The superior or anterior surface is united to the squamous 

 portion by the temporal suture and presents the following: 



An eminence , marking the position of the superior semicir- 

 cular canal; 



A depression, forming the roof of the tympanum; 



The hiatus Fallopii, transmitting a branch of the middle 

 meningeal artery and the petrosal branch of the Vidian nerve 

 to the aqueduct of Fallopius; 



Foramen for the smaller petrosal nerve; 



Orifice of the carotid canal, transmitting the carotid plexus 

 of the sympathetic and the internal carotid artery ; and 



Depression for Gasserian ganglion of the trifacial nerve. 



The posterior surface presents about its middle 



The meatus auditorius internus, at the bottom of which is 

 the lamina cribrosa, a perpendicular plate of bone., and numerous 

 foramina for the exit of the auditory nerve and the auditory 

 branch of the basilar artery, one of which is the commencement 

 of the aquacductus Fallopii for the facial nerve. 



Posteriorly to the internal meatus is the aquwductus ves- 

 tibuli, lodging a process of dura mater, and transmitting an 

 artery and vein, and between them another small depression for 

 the same purpose. 



The inferior or basilar surface presents, from within out- 

 ward, the following: 



A rough, quadrilateral surface, for attachment of the tensor 

 tympani and levator palati muscles; 



The opening of the carotid canal, transmitting the carotid 

 plexus of the sympathetic and the internal carotid artery; 



Aquceductus cochlece, transmitting a vein to the internal 

 jugular vein from the cochlea; 



Jugular fossa, forming the jugular foramen (foramen 

 lacerum posterius) by articulation with the occipital bone, and 

 transmitting the internal jugular vein, the glosso-pharyngeal. 

 pneumogastric, and spinal accessory nerves, and meningeal 

 branches of the ascending pharyngeal and occipital arteries; 



Foramen for Jacobsoris nerve, the tympanic branch of the 

 glosso-pharyngeal ; 



Foramen for entrance of Arnold's nerve, the auricular 

 branch of the pneumogastric ; 



Jugular surface for articulation with jugular process on oc- 

 cipital bone; 



The vaginal process, extending from the mastoid process to 

 the carotid canal, and ensheathing 



The styloid process, affording attachment for the stylo- 

 maxillary and stylo-l^oid ligaments and the stylo-hyoideus, stylo- 

 pharyngeus, and stylo-glossus muscles; 



