REVIEWS 123 



of protection seems to have led to the extensive scouring out of the 

 valley, and for that reason the interval is unusually broad. Elsewhere 

 it was observed that tributary streams have cut across the higher 

 terraces, whose exposed scarps remain in spite of the absence of any 

 protecting underlying ledges. 



Shore Phenome7ia 011 Lake Huron. By M. S. W. Jefferson. 



Kincardine, Ontario, is nearly one hundred miles north of Port 

 Huron, on the east shore of Lake Huron. As the shores there are 



BEACH CUSPS IX LAKE HURON'. 



undergoing uplift, there is an interesting contrast with geographic 

 conditions south of Gilbert's isobase, as at Muskegon, Lake Michigan. 

 There a line of dunes margins the "Big Lake," standing on a bar 

 which almost closes the river mouth, that expands behind into a con- 

 siderable lake, and is marshy, with typical drownedcharacter for 



