364 ROY L. MOODIE 
The endocranial capacity of this ancient wolf is suggested 
by the fact that the endocranial cast displaces 120 cc. of water. 
Endocranial blood vessels. The surface of the brain of 
Aenocyon is richly supplied with blood vessels, of which an 
interpretation is here given. The middle meningeal arises as a 
sharply marked artery, entering the skull through the foramen 
ovale. Immediately after its entrance into the endocranial 
cavity, it lies in a groove so deep and sharply cut as almost to 
be a canal. Coursing posteriorly, it emerges on the lateral sur- 
face of the brain at the lower level of the postero-lateral sulcus. 
The canal in which the artery runs is so sharp, as if it might have 
been cut on the inner table of the skull with a graver’s tool. As 
the artery approaches the ectosylvian sulcus, coursing anteriorly, 
it divides into three rami. The posterior arises at right angles 
to the main artery and supplies the surface posterior to the 
ectolateral suleus. The middle ramus runs also posteriorly, but 
supplies the upper parietal areas. The anterior ramus, inter- 
rupted in its direct course by the rami of the mid-cerebral artery, 
courses obliquely anterior, and supplies the anterior surfaces of 
the parietal areas and the posterior areas of the frontal region, 
where its minute subdivisions are interspersed between the 
ramifications of the anterior meningeal artery. The middle 
meningeal is thus the most important of all the arteries of the 
dura mater—more important even than in the human, in that it 
supplies a greater area. 
The anterior meningeal is not so readily followed, but it first 
appears alongside of the olfactory bulbs, sending many minute 
rami across the anterior dorsal region. 
A ramus of the occipital artery makes a rather well-marked 
groove in the cerebellar fossa, running almost parallel with the 
infero-lateral dural sinus. 
In the sylvian fossa is found the cast of a very large artery 
which is by no means as sharply marked as the middle meningeal. 
This artery I regard as the mid-cerebral artery, its indistinct 
canal being due to the interference of the dura mater. Its stem 
first appears as a well-rounded vessel between the optic chiasma 
and the root of the trigeminal nerve. Coursing at first slightly 
