38 THE DOG'S SKULL. 
FORAMINA AND APERTURES OF 
THE SKULL. 
The foramina through which the cranial nerves 
make their exit from the cranial cavity, and 
through which certain blood vessels pass, are as 
follows: 
i. The foramen magnum, a large median 
opening on the posterior end of 
the skull, in the occipital segment. 
Through it the spinal cord passes to 
the brain. 
ii. The condylar foramina pass obliquely 
through the ex-occipitals; at either 
side of the basi-occipital and anterior 
to the condyles, they transmit the 
hypoglossal nerve. 
iii. The foramen lacerum posterius is 
situated in front of the condylar, and 
between the ex-occipital bone and 
auditory bulla ; through it the glosso- 
pharyngeal, pneumogastric, and 
spinal accessory nerves make their 
exit, the internal jugular vein also 
passes through. 
iv. The stylomastoid foramen is a small 
irregular opening between the auditory 
bulla and the paroccipital process ; 
