5^ BULLETIN UNITED STATES GEOLOGICAL SUEVEY. [YolY. 



at each, extremity of the crown; its base is expanded posteriorly. The 

 principal cusp of the third premolar is more elevated, and, besides the 

 anterior and posterior tubercles, there is a basal posterior heel, which is 

 continued as an expansion of the inner base of the crown. In the fourth 

 premolar, the base of the crown is exjmnded, especially posteriorly ; the 

 principal cusp has a nearly circular section at the base, and the posterior 

 median lobe is a subconic tubercle standing on the middle of the heel. 

 The sectorial is large and relatively rather narrow, but the details of its 

 form are not ascertainable. 



Measurements. 



M. 



Lengtli of dental series, including canine and sectorial 0. 076 



Length of tlie base of the sectorial 0.024 



Length of the premolar series 0.037 



Leug'th of the fourth premolar 0.016 



Width of the fourth premolar 0.009 



Length of the third premolar 0.013 



Width of the third premolar 0.008 



Length of the second i)remolar 0.009 



Width between centres of crowns of fourth premolars 0. 034 



Length of symjihysis 0.035 



This' species was probably of the dimensions of the Gray Wolf. Found 

 by Mr. Sternberg in the same region as the U. ste^iocepJialus. 



Temnocyon altigenis Gope. 

 Oanis hartshornianus Cope 

 Canis geismarianus Cope. 

 Canis cuspigerus Cope. 

 Canis lippincottianus Cope. 

 Canis gregarius Cope. 



PEEISSODACTYLA. 



D^ODON SHOSHONENSIS CopC. 



AcERATHERiUM PACiPiciUM Leidy. 

 Anchitherium equiceps Cope. 

 Anchitheriuie brachylophum Cope. 



ANCHITHERIUiVI LONGICRISTE Cope. 



aetiodactyla. 



Elotherium imperator Leidy. 

 Pal^ochcerus condoni Marsh. 

 PAL^ocHOiRUS PRIST.INUS Leidy. 

 Pal^ochcerus sociALis Marsh. 

 Merycopater guyotianus Cope. 



