452 J. FRANK DANIEL 
posterior angle of the orbit, is the large facial foramen (f.VIJ), 
through which branches of the seventh or facial nerve pass. 
Almost in the same foramen but slightly ventralward and for- 
ward is a small opening for the entrance of the external carotid 
artery to the orbital region (f.e.c.’). Between the facial and 
optic foramina is a small perforation for the entrance of an artery, 
the ramus anastomoticus of Hyrtl (f.r-a.). This, in Gegen- 
baur’s (72) plate 2, figure 1, has been marked incorrectly the 
‘Querer Basalcanal.’ Above the facial is the large orbital fissure 
(o.f.) (trigeminal opening) through which pass the fifth, sixth 
and the first part of the seventh cranial nerves. Slightly above 
the middle part of a line connecting the orbital fissure and the 
optic foramen is the oculomotor (f.JJJ) for the exit of the third 
cranial nerve from the brain to muscles of the eye. Between 
the orbital fissure and the foramen for the ramus anastomoticus 
artery is the interorbital canal (7.0.) by means of which the 
orbital sinuses of the two sockets communicate. In the antero- 
dorsal angle of the socket are two foramina, the larger and upper 
of which is the ophthalmic (f.o.V/Z) for the superficial branch 
of the seventh nerve; the smaller and more ventrally placed is 
for the deep ophthalmicus profundus (f.o.p.). In the last 
mentioned opening is a second smaller foramen for the anterior 
cerebral vein. ‘This leaves the cranial cavity in the region above ~ 
the olfactory lobe. Below this, in the anteroventral angle of the 
socket is the posterior entrance to the orbito-nasal canal (0-n.) 
through which a vein passes from the olfactory region. (For 
the anterior end of this canal see o-n.’, fig. 2.) 
A median sagittal section through the cranium (fig. 5) shows 
the cavity for the brain. Surrounding this are the walls of the 
brain box through which the foramina lead. Dorsally the 
cranial roof or tegmen cranii varies considerably in thickness. 
Posteriorly and above the foramen magnum (f.m.) is a thick 
portion through the occipital crest (o.cr.). Anterior to this the 
wall pits sharply downward forming the parietal fossa. From 
this fossa the roof again arches upward and then, as the parieto- 
frontal groove, passes forward to the anterior fontanelle. 
