Brain of the Mastodon giganteus. 51 
equals in size. The vidian canal it would seem contained some- 
thing else than the vidian nerve, its size being wholly out of pro- 
portion to a filament comparatively so small, he foramen 
tncisivum is much smaller than in Elephants, and is prolonged 
as in them into a canal which in the Mastodon measures ten 
inches in length. 
_ The foramen magnum is nearly oval, being three inches in 
its transverse and two and a half in its vertical diameter. 
The openings between the nasal fossee and the diploic cells 
are very much larger than in the African elephant, and establish 
a free communication between these cells and the nasal orifices 
as far back as the occiput. 
Leaving out of view other resemblances between the skeletons 
of Mastodons and Elephants, an examination of the bones of the 
face, especially those in the neighborhood of the nasal openings, 
would afford satisfactory evidence that Mastodons like the Ele- 
Phants were provided with a nose elongated into a proboscis. 
Other evidence equally conclusive is found in a comparison of 
Some of the foramina in the base of the skull of these two genera. 
In Elephants the existence of a trunk, gives rise to the necessity 
for a corresponding development of the motor and sensitive nerves 
of the face and these in turn toa proportional enlargement of the 
Openings for their exit from the cranial cavity. ‘The foramen 
rotundum and foramen lacerum transmit the sensitive nerves, 
branches of the trigeminus, and the stylo-mastoid foramen trans- 
Mits the portio dura or motory nerve—and the two supply the 
hecessary filaments to the muscles and skin. In both Mastodon 
and Elephant these foramina present similar proportional sizes— 
but in neither is the stylomastoid foramen which transmits the 
motory nerve or portio dura, as largely developed as the foramen 
rotundum—the latter having a diameter of a half of an inch in the 
astodon and of seven-eighths in the Elephant, while the latter 
does not exceed one-fourth of an inch in either. Cuvier describes 
the great size of the orbitar and superior maxillary branches of 
the trizeminus and of the portio dura in Elephants,* and more 
recently Mayer has more fully described and figured the same 
herves, from a recent dissection of the parts.+ The complete 
Correspondence of these foramina in Mastodon and Elephant, 
Would have enabled the comparative anatomist to determine the 
pro existence of a trunk in the former, even if the bones of 
the base of the skull only had been brought to light, the rest of 
the skeleton being unknown. 
be acryey ge RC Ee 
.* Lecons @’ Anat, iii, pp. 199, 218. Paris, 1845. 
‘t Beitrige z A ia ei ‘Bighaniens und der iibrigen Pachydermen, von Dr. 
©. Mayer Noy. Act, Nat. Curios, T. xx, p.1. 1847. 
