PLATE VI 



FIG. 1. A region in a mature stage of erosion. Scale, about 2 miles per 

 inch. Contour interval, 100 feet. (Kentucky, U. S. Geol. Surv.) 



FIG. 2. A coast line developed chiefly by wave erosion. Scale, about 1 

 mile per inch. Contour interval, 25 feet. (Tamalpais, Cal., Sheet, 

 U. S. Geol. Surv.) 



