23 



column, but is separated from it by a distinct mammary tubercle or short column, which 

 has an anteroposterior ly short oval section. The heel of this tooth is broken off, but it 

 was small, judging by the fragments of its base. 



The peculiar column intercalated between the heel and the posterior internal column 

 distinguishes this species from all the selendont Artiodactyla known to me. 



The enamel is slightly wrinkled. The half-worn condition of the crowns show that 

 the animal was adult. 



Measurements. 



Mm. 



f Anteroposterior 0098 



Diameters of M. ii. ■{ Transverse 0070 



I 



I Vertical (of enamel) 0045 



In the superior molars the median and anterior external cingular cusps are large and 

 obtusely subconical. The anterior external cusp has a very strong median external rib, 

 while the posterior has a very weak one. The anterior horns of the internal crescents are 

 much produced ; the posterior but little. The cingula are slight, and are not continued 

 round the internal base. Diameter of superior molar : anteroposterior, 11 mm. ; trans- 

 verse, 11.5 mm. 



Leptomeryx semicinctus, Cope. 



American Naturalist, 1889, p. 154. 



A large species possessing twice the linear dimensions of the L. evansii in the superior 

 molar teeth, is represented by three of the teeth designated. In these the external cres- 

 cents are more compressed and less conical than the two species above described, resem- 

 bling more nearly those of the L. evansii. The posterior has a weak vertical rib ; the 

 anterior a strong one. The external cingular cusps are thoroughly fused with the exter- 

 nal crescents, forming their anterior horns. The anterior horns of the internal crescents 

 are a little more produced than the posterior. No external or posterior cingulum ; a much 

 interrupted anterior cingulum, which is continued round the internal base of the anterior 

 crescent, and which is further continued on the anterior side of the internal base of the 

 posterior crescent. Enamel finely wrinkled. Diameters : anteroposterior, 14 mm. ; trans- 

 verse, at base, 15 mm. 



