92 SKETCH or THE HISTORY Or MAMMALIA. 



47. — Molar of Mastodon, not worn. 



48. — Molar of Mastodon, much worn. 



in full operation, and ultimately, as in the elephant, 

 there is only one. That the mastodon had tusks like 

 the elephant is proved by the large alveoli for their re- 

 ception. As no perfect skull of the mastodon is known, 

 it is impossible to define its contour : it must, however, 

 have had a general resemblance to that of the elephant, 

 inasmuch as the tables of the frontal bone are separated 

 in a similar manner by extensive cells. 



The neck is short, and the skeleton generally (Fig. 

 49) approximates to that of the elephant. The masto- 



