Prof. E. D. Cope—On the Proboscidea. 445 
recorded by Whitfield from the Phosphate beds of South Carolina, 
and compared with M. obscurus.” A figure of the European form 
is given on p. 447, Fig. 6. M. (Tetrabelodon) euhypodon, Cope, is 
also from the Loup Fork beds of Kansas, and is known by a nearly 
perfect left mandibular ramus, with last molar tooth and tusk, and an 
entire palate with both last molar teeth and tusks. “The superior 
tusks,” says Cope, ‘‘are compressed distally, and the inferior tusks 
are large and have an enamel band; they are cylindric.” M. 
(Tetrabelodon) productus, Cope, is abundant in the Loup Fork beds 
of New Mexico; it is the only species in which three upper pre- 
molars have been demonstrated ; other species having generally two. 
M. Tetrabelodon campester, Cope, is a rather large species, with a 
very long symphysis of the lower jaw and a low ramus. It is in 
some measure allied to M. (T.) longirostris of Europe, but the 
symphysis is longer and the teeth more complex. ‘This species is 
also from the Loup Fork beds of Kansas and Nebraska. M. (Dibelo- 
don) Shepardi, Leidy, was founded on an inferior sixth molar from 
California. Cope subsequently described other specimens from the 
Pliocene of Mexico, where it is abundant. IM. (Tetrabelodon) serri- 
dens, Cope, was founded on a first or second true molar from Texas. 
It is peculiar among American species in its acute, elevated, entire 
crests with tuberculo-serrate edges. 
Mastodon mirificus, Leidy, is known from a left ramus of a lower 
jaw which supports the last molar. Its symphysis is short and acute. 
“ Mastodon Americanus, Cuv., is the best known and latest in time 
of the American elephants. It is one of the largest species, and, 
after T. brevidens, possesses the simplest molar dentition. The 
symphysis of the lower jaw is short and decurved. The skull is 
wider and less elevated than that of the Mammoth, and the tusks 
are shorter and less recurved. It was very abundant during the 
Pleistocene age throughout North America, from ocean to ocean, and 
as far south as Mexico; but it has not been found in the latter 
country. Its remains are usually found in swamps, in company 
with recent species of Mammalia, and with Equus fraternus and Bos 
latifrons, 'The carbonaceous remains of its vegetable food have been 
found between its ribs, showing that, like the Mammoth, it lived on 
the twigs and leaves of trees. 
It is at first sight curious that this, the simplest of the family of 
Elephants in the characters of its molar teeth, appears latest in time 
on this continent. But it must be regarded as an immigrant from 
the Old World, where an appropriate genealogy may be traced. Its 
nearest ally, Mastodon borsonii, existed just anterior to it, during 
the Middle and Upper Pliocene, and this species was preceded in 
turn in the Middle and Upper Miocene by the T. turicensis, which 
possesses the same simplicity of the molar teeth. In its mandibular 
tusks the latter possesses another primitive character which was 
nearly lost by its North American descendant.” — 
“ Hlephas primigenius, Blumenbach, ‘the Mammoth,’ was at one 
time distributed throughout North America, as far south as the 
valley of Mexico inclusive. Its remains are found in the Upper 
