40 THE DOG'S SKULL. 
it transmits the main trunk of the 
facial nerve. 
v. The external auditory meatus is the 
large dorso-lateral opening in the 
auditory bulla. 
vi. The post-glenoid foramen is situated 
immediately behind the process of 
the squamosal; it transmits a vein 
from the lateral sinus. 
vii. The foramen lacerum medium is 
an oval aperture between the posterior 
portion of the ali-sphenoid ; through 
it the internal carotid artery passes 
to the cranial cavity. 
viii. The internal auditory meatus is 
situated on the cranial side of the 
petrous portion of the periotic, and 
permits the passage of the auditory 
nerve (viii) to the internal ear, and of 
the facial (vii) to the stylomastoid 
foramen. 
ix. The foramen ovale opens at the basal 
portion ot the ali-sphenoid. It trans- 
mits the third or mandibular division 
of the fifth nerve. 
x. The ali-sphenoid canal opens im- 
mediately in front of the foramen 
ovale. It passes in a horizontal direc- 
tion forwards in the ali-sphenoid, and 
opens into the foramen rotundum. 
