CENOZOIC ERA. AGE OF MAMMALS. 



389 



or perhaps beyond the lakes, but again advanced, and 

 formed the deeply lobed moraine marked by the dotted 

 lines. 



We have given only the limit of the general ice-sheet. 

 But in mountain-regions, e. g., in Colorado, and perhaps 



FIG. 347. Map showing limit of the drift and the second ice-sheet moraine. Limit 

 of northern drift represented by heavy line from Long Island to Minnesota ; 

 second ice-sheet moraine represented by triple dotted line. 



in Virginia, even beyond this limit, there were great 

 separate glaciers, occupying the valleys, as shown by the 

 moraines left by them. The tracing of the course of 

 these old glaciers by their glaciated pathways, perched 



