ENDOCRANIAL ANATOMY OF FOSSIL MAMMALS 357 
similar relations. Its prominence is due partly to the rather 
unusual extent anteriorly. The surface of the lobus anterior was 
a broad, uniformly arched dome similar to the condition found 
in other cats. On all these subdivisions traces of lamellae are 
evident, but nowhere are they sharply marked. ‘They are most 
in evidence on the lobulus paramedianus. <A broad foliate 
lobulus petrosus is also evident on one side, but no details of its 
structure can be made out. 
The preservation of the meningeal vessels in the endocranial 
east of the undetermined felid (Hoplophoneus?) is worthy of 
note. The prominence of the superior sagittal sinus has already 
been mentioned. It rises as a prominent arch posteriorly and 
evidently sank, anteriorly, between the medial cerebral surfaces. 
Into the arched portion of this sinus emptied four prominent 
meningeal veins. The veins are not paired, but served to drain 
the postero-lateral surfaces of the cerebrum. The postero-lateral 
dural sinus was robust, extending along the tentorial line. Traces 
of two prominent arteries are evident. One, corresponding to 
the middle cerebral artery of the human brain, runs along the 
floor of the sylvian fissure, bifurcating at the edge of the ecto- 
sylvian sulcus. From there spreading indistinctly over the 
parietal area of the cerebrum, another smaller artery, the middle 
meningeal, appears to have entered the brain-case through the 
foramen ovale, sending two prominent rami anteriorly across the 
areae pyriformes, and another smaller ramus running approxi- 
mately parallel with the postero-lateral sinus. Minute rami are 
indicated on the frontal portions of the cast, but their origin 
is uncertain. 
Smilodon. The machairodonts reached their maximum devel- 
opment in the Pleistocene, and I have been fortunate, through 
the kindness of Mr. E. 8. Riggs, in being able to study the left 
cerebral surface (fig. 16), of a giant saber-tooth cat or tiger, 
Smilodon, from the Pleistocene asphalt of the Rancho la Brea 
beds near Los Angeles. Scott (’13), in the frontispiece to his 
book, has given a striking reconstruction of this huge cat. The 
material at my disposal consists of the left, posterior lateral 
portion of the brain-case of an adult cat. My interest in the 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 34, NO. 4 
