530 



University of California Publioations in Geology [Vol. 10 



The lower tooth from locality 3036C from the Snake River is 

 slightly more Pliohippus-like than a large lower tooth from the ex- 

 posures near Ringold. In the Idaho specimen the inner faces of the 

 protoconid and hypoconid are a little less flattened, and the inner 

 groove of the metaconid-metastylid column is much narrower and much 

 more acute. In this respect the Idaho specimen is more Pliohippus- 

 like than that from the beds near Ringold. 



A number of specimens representing foot-bones of a large horse 

 from beds referred to the Idaho show no evident characters distinguish- 

 ing them from the corresponding elements of Pleistocene species of 

 Equus. 



Comparative Measurements 



Large Individuals 



E. idaho- E. idaho- , * > 



ensis ensis ? E. occi- E. paci- 

 Pi? Ml? dentalis ficus 



No. 22348 No. 22346 P2 Pi 



Anteroposterior diameter 35.5 mm. 33 34 34.5 



Transverse diameter 34.8 30.6 28.7 32.5 



Height of crown 24.7 81 



No. 22347 



Anteroposterior diameter 34 34.5 



Transverse diameter 18.8 18.3 



Anteroposterior diameter of metaconid-meta- 

 stylid column 19.8 



Height of crown 72 



