Cope.] 5o4 [March 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. Cope. 



{Bead before tlie American PJiilosophical 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 conic 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 is a 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 crown 130 



Longitudinal " " internal 070 



" " " external 090 



J 



