334 DAVIDSON BLACK 
which pass the ophthalmic and maxillary divisions of the fifth 
nerve together with the oculomotor, trochlear and abducent 
nerves. The prominence labeled Oph. & Mz.V represents a 
deep skull groove, the floor of which is occupied in the recent 
state from the medial to the lateral side respectively, by the 
ophthalmic and maxillary divisions of the trigeminus. The 
rostral limit of this prominence corresponds to the position of 
the anterior lacerated foramen. The site of the foramen ovale 
transmitting the mandibular division of the trigeminus and the 
slight groove occupied by this root, is indicated in the figures 
by the legend, Md.V. From the base of this ‘‘mandibular”’ 
elevation a ridge is evident in figures 3 and 19, passing dorso- 
caudally, which represents a skull groove along the attached 
border of the tentorium. This groove leads into the parieto- 
temporal canal (meatus temporalis) and in the recent state is 
occupied by the vena cerebralis dorsalis, which is in turn con- 
tinuous with the transverse sinus. 
The internal auditory meatus for the passage of nerves VII 
and VIII is indicated by a circumscribed elevation capped by two 
bosses and situated about 10 mm. behind the base of the ten- 
torial ridge. The VII and VIII eminence is placed in the middle 
of a somewhat depressed area which is moulded by the periotic 
bone. Inferiorly, this area terminates at the foramen lacerum 
basis cranil. Through this foramen in the recent state pass the 
internal carotid artery, the middle meningeal artery, the IX, 
X and XI nerves and the inferior cerebral vein. The position 
occupied by this foramen is indicated in the cast by the irregular 
ridges on each side of the basi-occipital or pontine region. 
No indication as to the relative development.of the pons and 
corpus trapezoides can be obtained from the cast. These 
structures are apparently separated from the floor of the bony 
cranium as in the cow, by a bridge of dura beneath which is 
lodged the plexus of the basilar smus. ! 
The position of the condylar foramen is evidenced by a slight 
elevation on the lateral, caudo-ventral surface of the cast. 
This cast gives but little information as to the morphology 
of the cerebellum save to indicate the presence of cake-like floc- 
