162 



Annals of the Carnegie Museum. 



Measurements. 



Mm. 



Length of P^ and the 3 molars. 42 



Length of molar .series 32 



Length of P^ 10 



Length of Mi 10 



Width of Mi 16 



Length of M^ 11 



Width of M- 17 



Length of M-i 11 



Width of M^ 15.5 



Found on Thompson's creek. 



ARTIODACTYLA. 



Trigenicus socialis gen. et sp. nov. 

 No. 817. Fig. 6. 



In the autumn of 1901 the writer reexamined a portion of the 

 lower White River beds on Thompson's Creek near Three Forks. 

 In a place where fragments of several skulls (including the types of 



Fig. 6. Trigenicus socialis (No. Si 7), White River beds, near Three Forks. 

 Natural Size, a, portion of skull ; b, crown view of teeth. 



Limnenctes phifyceps and L. ? anceps) had been found, the anterior 

 portion of another skull was obtained. It is laterally crushed at 

 muzzle. It does not exactly correspond with anything that has been 

 described, though it bears resemblance to several of the Uinta and 



