276 
THE WASATCH FAUNA. 
Miocene of Pikermi, tlie brain of the HippotJierium {Hipparion) shows itself 
a little less rich in convolutions than that of the existing Horse; and in a 
fragment of a skull of a Monkey, from the same locality, which I have been 
permitted to examine in the museum, the cerebellum is less completely cov¬ 
ered by the hemispheres, and the median vermis is more prominent than in 
the living Semnopitheci, of the types most nearly related to those of Pikermi. 
But, in order to show more clearly this disproportion of the fossil brains in 
relation to those of living Mammalia^ it is necessary that comparison should 
be made between species of the same family, or, better still, of the same 
genus. It has been possible for me to verify this point by the oomparison 
of two carnivorous animals, the living Viverra genetta and the extinct Fi- 
verra antiqua of He Blainville from the Inferior Miocene of Allier. From 
this, it appears that, with a cranium one-third longer and one-fourth wider 
than the living V. genetta^ the fossil F. antiqua has not a larger brain, and 
that this brain, more attenuated in its frontal convolutions, does not extend 
so far forward. According to Gratiolet, a great development of the olfac¬ 
tory lobes is a character of an inferior type. In fact, the more we ascend 
into paleontological antiquity, the more we find the olfactory lobes to dis- 
pla}^ a great development in comparison with the cerebral hemispheres.” 
The Wasatch horizon is lower than the oldest above referred to by 
Professor Lartet, and it is interesting to observe how his generalization 
with reference to the characters of the Mammalian brain is confirmed. The 
OxycBna forcipata approaches more nearly to the Viverrine type than to any 
other form of the Carnivora, although separated by a wide interval. I have , 
been able to obtain a cast of the superior and anterior portions of its cranial 
chamber, from which it appears that the brain possesses characters of a 
much lower type than that observed in the Viverra antiqua. The olfactory 
lobes are enormously developed, rising higher than the hemispheres, from- 
which they are not only entirely free, but are separated by a constriction 
of their basal portions. The hemispheres are not wider at the middle than 
the olfactory lobes, and have therefore elongate proportions. Their supe¬ 
rior portion is Avithout convolutions, although not a Marsupial. The gen¬ 
eral form in Oxycena is more like that of the Opossum than that of any 
other living animal, but is still lower in character. Its inferiority is 
