358 ROY L. MOODIE 
brain was at once aroused by the very sharply marked inner 
table of the skull where the sulci and gyri were shown reproduced 
in a striking pattern. Figure 16 shows the plaster cast made 
from this incomplete skull, after the asphalt had been carefully 
removed. The tentorium was damaged, but enough remains to 
tell something of the nature of the cerebellum. The inner surface 
of this skull is more sharply marked than in any other mammal 
which I have seen. 
The cerebrum is typically aeluroid and shows a close com- 
parison with the brain of the lion (Elliot Smith, ’02, p. 233), 
the largest modern cat brain I can find figured. Only the pos- 
terior two-thirds of the Smilodon brain is shown. The gyri are 
large and prominent and the sulci deep. The lateral sulcus 
(S.lat.) in Smilodon has almost precisely the same relations as 
in the modern lion. The anterior end of this sulcus is lost and 
the presence or absence of an ansate sulcus impossible to deter- 
mine. The postero-lateral sulcus is not indicated, but may 
have been present in the brain. The post-sylvian (S.postsyl.) 
and its continuation, the suprasylvian (S.ss.), have almost 
precisely the same course in Smilodon as in the lion, except for 
the presence of small bifurcations which cannot be determined 
in the fossil. The posterior ectosylvian sulcus (S.ectosyl.p.) is 
almost exactly the same in the two forms. Only a portion of 
the anterior ectosylvian sulcus (S.ectosyl.a.) is indicated in the 
ancient cat. <A slight depression at the anterior end of the cast 
is identified as the rhinal fissure (F.rhin.). The identification of 
the sulcus diagonalis (S.diag.), in view of the absence of the 
anterior portion of the cerebrum, is uncertain. The sylvian 
fissure (/.syl.) is more vertical in Smilodon than in the lion, 
and its termination is simpler. If we may be permitted to judge 
from this portion of the cerebrum which we have preserved, we 
may say that the cats had attained their cerebral complexity 
with a surprising degree of completeness by Pleistocene times. 
The posterior width of the cerebrum is 68 mm., the estimated 
length is 75mm. A single gyrus measures 9 mm. across. 
The cerebellar fossa of the incomplete brain case is rather 
imperfect, so that a careful study of the cerebellum is not possible. 
