MASTODON 353 



or two-ridged type is shown by the molars of the Tapir, 



(fig. Ill), Lophwdon, Megatherium, Dijjrotodon, Nototherium, 



Kangaroo, and Manatee. In 



the general shape of the skull 



and aspect of the nostrils Dino- 



therium most resembles Mana- Fig. 1 1 1 . 



tus. Bones of limbs have not Molar series > lower jaw, Tapir. 



yet been found so associated with teeth as to determine the 



ordinal affinities of Dinotlierium. Yet cranial and dental 



evidences of the genus have been discovered in miocene deposits 



of Germany, Fiance, Switzerland, and Perim Island, Gulf of 



Cambav. 



Genus Mastodon, Guv. — The earliest appearance of this 

 genus of proboscidian or elephantoid Mammal is in tertiary 

 strata of miocene age, and by a species in which the fore part 

 of the lower jaw was produced into a pair of deep sockets 

 containing tusks ; but these are only slightly deflected from 

 the line of the grinding teeth (fig. 112, (J). This species of 

 Mastodon, discovered in the miocene of Eppelsheim, was called 

 longirostris by Kaup ; but he afterwards recognized it as the 

 same with a species which had been previously called Masto- 

 don arvemensis (Croizet and Jobert).* Both belong to that 

 section of Mastodon in which the first and second true molars 

 have each four transverse ridges, t and for which Dr. Falconer 

 proposes the name Tetralophodon. In the newer tertiary 

 deposits of North America remains of a Mastodon (M. Ohio- 

 ticus) have been discovered, in which the transverse ridges of 

 the grinders are in shape more like those of the Dinothere 

 than in any other Mastodon ; the first and second, moreover, 

 are bilophodont, the third trilophodont ; but this is followed 

 by two three-ridged molars and a last larger molar with four 



* Beitrage aur Naeheren Kenntniss der Urweltlichen Saeugethiere, 4to, 

 1857, p. 19. The name angustidens was firnt applied by Cuvier to teeth of this 

 typo or species. 



f First demonstrated by Kaup, Ossemens FoaBilea de Darmstadt, 4to, 1835. 



2 A 



