54 Dr. Wyman on the Cranium, &§c. of Mastodon giganteus. 
In Mastodon then as in Elephant the transvere diameter of the 
brain exceeds the longitudinal, though to a less extent in the 
former than in the latter; this condition of things exists only in 
a few instances in the Mammiferous group, and is found princi- 
pally if not wholly in Cetaceans and Proboscidean Pachyderms.* 
In Cetaceans the transverse diameter is in still greater excess over 
the longitudinal, but the cerebral lobes together form a regularly 
oval mass; in which circumstance it makes a striking contrast 
with the same parts in Elephants and Mastodons. Fig. 3 repre- 
peculiarity which Camper seems to have entirely overlooked. 
: 8. 
I 
ELEPHANT. 
ion.— s.—Il. Ce i é —IV. 
thedota ena cc eer sisal lobes —II. Cerebral Hemispheres.—III. Cerebellum. 
The cerebellar fossa is well defined, and shows a considerable 
elevation of the cerebellum, which it appears must have beet 
more uncovered by the cerebral lobes than in Elephants. 
The resemblance between the forms of the brain in Mastodons 
and Elephants, is also of great interest in a zoological point of 
view. ‘I'he general conformation of the skeletons of these tw? 
* Soe Cuvier Oss, Foss, T.i,p.481. sdeedition aoa 
