Cope,] 584 {Mareh 2, 
have identified in New Mexico as the Trias, and is of the usual red color. 
The occurrence of a terrestial Dinosaurian at that locality tends to con- 
firm the conclusion to which I have already attained, that this immensely 
extended deposit is of lacustrine character. 
On a New Proboscidian. 
By E. D. Cops. ‘ 
(Read before the American Philosophical Society, March 2, 1877.) 
I recently received from a correspondent in one of the Southern States, 
a fossil of unusual interest. It is a molar tooth of a proboscidian, whose 
color and mineral character indicate that it was derived from beds of the 
Upper Miocene or Loup Fork epoch. Its roots are largely broken away, 
while the crown is nearly perfect. 
The crown consists chiefly of two transverse crests, which are separated 
by a deep uninterrupted valley. There is no general cingulum. Each 
crest is divided into three lobes, which are not deeply separated, but cause 
the edge of the crest to be serrate with three conie eminences. Of these 
the median apex has a rounder section, while the lateral are more trans- 
verse, rising at the external borders like the extremities of the crests in 
Mastodon ohioticus. The appearance of the base of the crown at one ex- 
tremity indicates that it was in contact with the preceding tooth. The 
opposite extremity of the base presents no such surface, and hence points 
to the conclusion that the tooth is the last one of the series. From the 
middle cone of the anterior crest a cingulum descends on each side, passing 
round the anterior base of the external cones. It is wanting at the ex- 
tremity of the base of one of these, and little developed on the other, but 
they reappear on the side of the base bounding the valley. They are 
crenately tubercular, except at the base of the median anterior tubercle. 
There is no cingulum at the base of the posterior crest, except the ordinary 
filling between the bases of the lobes, One of the extremities of the crests 
is a little higher than the other, and the basis is a little wider than at the 
other end ; it is therefore probably external in position. At the posterior 
base of this end isa fractured surface indicating a cingular tubercle of 
stout proportions, such as is more in place at the external posterior angle 
of the last superior molar than in any other tooth. 
The external cone is defined from the median by a fissure, while a better 
defined depression separates the median from the internal. This depres- 
sion is filled by a worn tubercle in the anterior crest. Ridges descend 
along the adjacent borders of the constituent cones nearly to the fundus of 
the valley, and the bases of the external ones are considerably wrinkled. 
Measurements. M. 
Transverse diameter Of CrOWD........ ee ee rece eete renee .130 
Longitudinal “ «© jnternal........eeeeeeeee .070 
as es @xlermalls.ccicascesendaex -090 
