62 Dr. Wyman on the Cranium and 
There is no peculiarity of the interior of the cranium of the 
Mastodon which more forcibly presses itself nn the notice of 
the comparative anatomist than its form; in this we have Te- 
vealed to us the general outline and some of ~ details of the 
surface of the brain of which the cranial walls are on an accurate 
mould; and in this too we have additional means of making com- 
parisons between the genera of Mastodon and Elephant and of 
determining another important element in their affinit 
The following measurements vary but little from those green 
by Dr. Warren in his memoir already cited.* 
Inches. 
Greatest length of cranial cavity on median line from 
crista galli, to inner edge of foramen magnum 93 
Greatest length from anterior part of ba fs fossa 
to edge of foramen magnum, - 10 
ene height on median line 5t 
Transverse diameter at posterior bee of opie etait 7t 
mT eaiibeetse? diameter at anterior edge of occipital fossa, 57 
ransverse diameter through the centre of middle fossa, 104 
As however the cranium under consideration belonged to an 
immature Mastodon, but little of moment was deduced from 
its measurements or capacity merely. It is to the form of the 
whole and of its subdivisions that the principal interest attaches 
—and these next present themselves for description 
The Olfactory lobes are quite large in both the Mastodon and 
Elephant, when compared with the sensitive surface over which 
they preside, the index of this last being the turbinated portion ¢ of 
the ethmoid bone. The olfactory fossa i in Mastodon is of a pyle 
form shape 28 inches long by 12 in the broadest part, and is seve 
times longer in actual extent than the corresponding fossa in the 
ox or the horse; in the former the fossa measuring 1} inch by 
Sth of an inch. On the other hand the sensitive surface of bo 
these last mentioned animals is actually much longer than the cor 
The Cer oral A Pea as an inspection of the eer 
nying figures, 1 and 2, will at once indicate, are the parts of all 
pees which present the most characteristic feature of the et 
halon. ‘The anterior lobes are contracted to a most extfa — 
ordinary degree, each having the fim of a sottaat mass with the 
* Page 119. | 
| 
