302 



MAMMALIA. 



pair of recurved incisors or tusks, which seem to have grown from per- 

 sistent pulps, but do not exhibit the characteristic elephantine "engine- 

 turned" structure when examined in transverse section. The dental 



formula of the adult is ^-, ' c ' ' pm ' > m ^- and all these teeth are 

 i. 1, c. 0, pm. 2, m. 3 



simultaneously in use. Each of the premolars has two transverse ridges, 

 which are connected in the upper jaw (fig. 173) by a longitudinal 

 ridge on their outer side ; the true molars, both above and below, bear 

 respectively three, two, and two ridges. There are three milk-molars 



FIG. 172. 



Dinotherium giganteum ; imperfect skull and mandible, one-fifteenth nat. 

 size. L. Pliocene ; Eppelsheim, Hesse Darmstadt. (After Kaup.) 



in both jaws in young individuals, which have respectively two, two, 

 and three ridges ; but the foremost tooth is small and not replaced 

 when shed. Only two imperfect skeletons definitely associated with the 

 characteristic jaws are known, namely, from the Miocene of Abtsdorf 

 and Franzensbad in Bohemia ; but several isolated bones have been 

 assigned to Dinotherium with much probability of correctness. All com- 

 parisons of the vertebrae and limb-bones hitherto made, tend to demon- 

 strate its truly Proboscidean nature. The typical species is Dinotherium 



