66 



Foro aud aft. 



Diameter of first premolar . . 

 Diameter of second premolar 

 Diameter of third premolar. 

 Diameter of fourth premolar 



Diameter of first molar 



Diameter of second molar . . . 

 Diameter of third molar. . . . 



Lines. 



^ 



G 

 Gh 



Lines. 



u- 



5^ 

 8i 



Transverse. 



IjUK'S. 



2.i 



u 



Tj'uiv 



2i- 



3i 



4 



5 



5 



Hijrackyus agrari>(.s was al:)uut the size of the coininoii collared peccary, 

 Dicotyles torquatus. 



HYRACHYUfcj liXIMIUS. 



A .supposed larger species of Hyrachyus lluui H. dgrarius is interred IVoin 

 several specimens, consisting of small fragments of a lower jaw with a tooth 

 and portions of others. These were obtained by Dr. Carter on Henry's Fork 

 of Green River. 



The best and most cliaraeteristic specimen is represented in Figs. 19, 20, 

 Plate IV, consisting of a lower-jaw fragment containing the last premolar and 

 portion of the first molar much worn. Both the teeth and the jaw agree in 

 form with the corresponding parts in Hyrachyus agrarius and differ only in 

 size. The specimen also agrees with the" corresponding ])art of Lophiodon 

 sufficiently to belong to the same genus, so that until more amjile material is 

 discovered it must remain uncertain whether it really i)ertains to Hyrachyus. 



Comparative measurements are as follows : 



H. oxiiiiius. H. ;nrrariii.s. 



Lines. 



Depth of jaw at last premolar 



Thickness of jaw at last premolar 



Diameter fore and aft of last premolar. 

 Diameter transversely of last premolar 



Diameter trausversly of first molar 



Diameter transversely of second molar. 



Figs. 9, 10, Plate XXVl, represent a tooth recently obtained by Dr. Cai^- 

 tcr on the buttes of Dry Creek. It would apjiear, from its proportions, to l)e 

 (lii^lcfl lower ])eiinltimate molar of //y)Y?''////WA- czimiu^. It is a nearly un- 



