2 2 Bulletin American Miiseian of Natural History. [Vol. XIV, 



in the teeth above mentioned to distinguish them from E. tau they 

 should provisionally be referred to this species, although the two 

 localities are so widely separated. Future discoveries may prove 

 that the teeth from the southeastern United States belong to a 

 distinct species. 



(14) Eqiius crenidens Cope. 



Type Locality. — Tequixquiac, Valley of Mexico. 



Type. — Fragment of upper jaw containing the premolars of one side. 



Author's description. — "This species is primarily distinguished by the close 

 and strong wrinkling of the enamel border of the lakes of the superior molar 

 teeth. This wrinkling, or vertical plication, reminds one of what is seen in the 

 Elephas indicus. This wrinkling is not found in the enamel edges which border 

 the interior crescents on the inner side, nor in those bordering the internal lobes 

 or columns. The borders of the lakes are not folded in the complex loops seen 

 in Equus major Dek. ,but have the plainer looping seen in Equus tau Ow 

 The grinding faces are nearly square. . . . The crimping of the enamel of 

 the lakes distinguishes this species from the others of the genus." 



Measureineiits given . 



., ( Antero-posterior diameter 43 mm. 



( Transverse " 30. 5 " 



P^ I 



Antero-posterior " 33.5 



Transverse " 34 



4 ) Antero-posterior " 31 



( Transverse " 35 " 



Although a minute description and measurements have been 

 given, this species appears to be indeterminate. As seems usually 

 to have been his custom, Cope has given the transverse measure- 

 ments of the teeth, including the cement, hence they are not of 

 much value except in as far as they show that the type of E. 

 crenidens is of a large horse, apparently about the size of E. pacifi- 

 cus or the somewhat smaller E. scotti. The crimping of the 

 enamel which Cope seemed to consider the distinguishing char- 

 acter is probably not more than an exaggeration of the same 

 character often indicated in the premolars of E. caballits. That 

 Cope himself did not place great reliance on this character is 

 evidenced by the fact that he afterward described and figured a 

 large tooth from southwestern Texas,' referring it to this species, 

 which shows no uncommon tendency to any such wrinkling. 

 This tooth, however, from its enormous size evidently belongs to 



1 Am. Nat., 1885, p. 1208, fig. 4 (No. 8616, Am. Museum Nat. Hist., Cope Coll.). 



