260 The Parallel Drift-Hills of Western New Yorl:. 



Though this summary is in general very satisfactory, the last 

 statement, namely, that the local glacier which finished the 

 excavation of the Ontario basin ''was deflected by the highlands 

 south of the lake-basin, so that its motion was nearly westward," 

 if ajiplied to the region which we are considering, would seem 

 to require modification. The direction of these drift-ridges, to- 

 gether with their steep northern declivities, render it evident 

 that the glacier which deposited them came from and retired to 

 the north. Professor Newberry's remark might, however, be 

 applied witliout change to the western portion of the Ontario 

 basin, for in that locality there are no drift-ridges, showing a 

 different direction of the ice-flow, while the course of the 

 glacial striae upon exposed rock-surfa'ces supports the view. 

 These latter, unfortunately, are not accessible to any great ex- 

 tent in the region occupied by the drift-hills. I regret that I 

 cannot offer their evidence in corroboration of that afforded by 

 the hills. We have, however, what I conceive to be much more 

 important testimony — the direction of the long axes of the cliain 

 of small lakes south of the hills. A glance at any map of New 

 York will readily show that lines drawn through the long axes 

 of Canandaigua, Sene(^a, Cayuga, Owasco and Skaneateles lakes, 

 converge toward a point on the Canadian shore of Ontario. 

 That these lake-basins were excavated by glacial action, seems 

 almost self-evident, and is, indeed, almost universally admitted. 

 Their radiated arrangement, in my opinion, admits of but one 

 explanation, namely, that they were cut by one and the same 

 great glacier, whose margin was broken into several streams in 

 crossing the mountain ridge, and that this glacier flowed in a 

 general southerly direction from the Canadian highlands. Fur- 

 thermore, the maxim nm of its force was exerted along its cen- 

 tral line, in the vicinity of Seneca and Cayuga lakes. Opposite 

 these lakes the shore of Ontario is deeply indented by a number 

 of bays, notably by Big Sodus. That the glacier occupied this 

 region for an immensely long period of time, is evident from the 

 great depth of the rock-basins of Cayuga and Seneca, — the for- 

 mer having now a depth of more than fonr hundred, and the 

 latter of more than six hundred feet. As stated above, Cayuga 

 formerly extended a dozen miles or more further north than 

 now. Its buried basin has been sounded at Montezuma, in 



