Prof, E. D. Cope—On the Proboscidea. 439 
- But two families of Proboscidea are known. ‘They are defined as 
follows : 
Adult dentition embracing premolars and molars; no superior 
Incisors—Dinotheriida. 
Adult dentition embracing one or two true molars only ; superior 
incisors—LHlephantida. 
The family of the Dinotheriide embraces one genus and four 
species, though a fifth species, D. sindiense, Lyd., from India, may 
belong, according to Lydekker, to another genus. The Dinotherium 
indicum, Falc., is known from a few teeth, which exceed in size those 
of the other species. The D. giganteum, Kaup, is found in several 
Fig. 1.—Dinotherium gigantewm, Kaup, from the Middle Miocene of Samaran 
(Gers), France. (After Gaudry.) ‘The left upper cheek-dentition ({ nat. size). 
a@ 1, 2, 3, true molars, p. 8, 4, premolars. 
Miocene deposits of HKurope. It was one of the largest of Mammalia, 
its femur exceeding in dimensions that of any other land mammal. 
The inferior incisors were robust, and cylindric in form. With the 
symphysis of the lower jaw they are decurved so as to form a most 
effective instrument for the tearing up of trees by the roots, or the 
pulling down of their branches. ‘The temporal fossa is lateral, and 
the top of the head flat. The premaxillary region, though toothless, 
is prominent, and the nasal bones do not project. There is supposed 
to have been a short trunk. The skull measures three feet eight 
inches in length. Two smaller species are known, the D. bavaricum, 
from European, and D. pentapotamia, from Indian, Miocene beds. 
In Dinotherium all the molars and premolars have two transverse 
crests, excepting the first (posterior) premolar, and its deciduous 
predecessor, which have three cross-crests. 
The genera of the Hlephantide are the following : 
I, Inferior incisors and premolars present. Superior incisors with enamel band— 
Tetrabelodon, Cope. 
II. Premolars, but normally no inferior incisors ; intermediate molars isomerous ; 
superior incisors with enamel-band — Dibelodon, Cope. 
Intermediate molars isomerous ; superior incisors without enamel band—Mas- 
todon, Cuv. 
Intermediate molars heteromerous; superior incisors without enamel band— 
Emmenodon, Cope.} 
III. No premolars, nor inferior incisors. 
Intermediate molars heteromerous. Superior incisors without enamel band— 
Hlephas, Linn. 
1 Gen. noy. type, Hlephas Cliftii, Fale. & Cautl. (Mastodon elephantoides, Clift). 
