1913] 



Merriam : Fauna of Orindan and Siestan 



385 



Neohipparioii, suggesting the Orindan fauna. The Ricardo fauna 

 is possibly somewhat later than that of the best known horizon 

 containing the Mohave fauna in the Barstow syncline. 



Considering the indefmiteness of all the factors concerned, 

 one would not seem justified in being more definite than to state 

 that the Orindan and Siestan faunas are near a late Miocene 

 stage. When the faunas of the two formations are better known, 

 it may appear that more than one stage is represented. 



Transmitted June 28, 1913. 



