21G 



LEPTOMERYX. 



Leptomekyx Evansi. 



A small ruminant, related to the musks, was originally described under the 

 above name, from remains discovered by Dr. John Evans and Professor llay- 

 den in the Mauvaises Terres of White River, Dakota. 



Two small fragments of jaws, the one containing a well-preserved upper 

 molar and the other a lower molar, from John Day's River, agree in all re- 

 spects with the corresponding parts of Leptomeryx Evansi. 



AGRIOCHCERUS. 



Ageiochcerus antiquus. Ageiocuceeus latifrons. 



The above genus and species were originally characterized from remains 

 found in the Mauvaises Terres of Dakota. The genus is related with Oreodon, 

 but exhibits peculiarities enough to regard it as pertaining to another family 

 of extinct ruminating hog-like animals. 



A small fragment of an upper jaw with portion of a molar, and a few frag- 

 ments of detached molars from John Day's River, appear to indicate the 

 presence of both the above-mentioned species. 



Artiodactyla. 



DICOTYLES. 



DlCOTYLES PEISTINUS. 



An extinct animal about the size of and nearly allied to the living collared 

 peccary, Dicotyles torquatus, .is represented in the Condon collection by 

 several detached lower molar teeth. These have nearly the size and consti- 

 tution of those of the collared peccary, though considerably worn and there- 

 fore smoother than when in a younger condition. Independently of this 

 smoothness, due to age, the constituent lobes of their crowns do not present 

 the wrinkled condition observed in the living peccaries. 



The last lower molar, represented in Fig. 14, Plate VII, has a five-lobed 

 crown with a basal ridge in front and externally, and also postero-internally. 

 The lobes of the crown are comparatively simple, or but slightly complicated 

 by offsets or folds. The penultimate molar, represented in Fig. 13, Plate VII,. 

 has four principal lobes to the crown, arranged as in the recent peccary. 



An upper molar, from a younger animal, perhaps, belonged to the same 



