37o 



University of California. 



[Vol. i. 





EURASIA 



NORTH AMERICA 



Recent 



Castor fiber var. 



Castor fiber var. canadensis 



Quaternary 



Castor fiber var. ^fo'r 

 Trogontherium Cuvieri 



Castor fiber var. canadensis 



Pliocene 



Upper 



Castor issiodorensis 

 Trogontherium Cuvieri 



Castor fiber var. canadensis 



Lower 



Steneofiber ( Chalicomys) 



sigmodits. 

 Castor pel ice dens (?) 

 Castor Rosincc [? ) 



Sigmogomphius Le Contei 

 Encastor tortus 





u 

 1) 

 a 

 a 



Steneofiber Jccgert 



Mylagaulns monodon 

 Mylagajilus sesquipedalis 



ocenk 



_v 

 ■a 

 ■a 



i 



steneofiber Jcegeri 

 Steneofiber mimitus 



Steneofiber montanns 

 Steneofiber gradatas 





Lower 



Stoieofiber eseri 



Steneofiber nebrascensis 

 Steneofiber peninsulatus 

 Steneofiber pansus 



o 



Geological Laboratory , 



University of California, February, /8p6. 



