DISCO VERY 



OF THE 



Preglacial Outlet of the Basin of Lake Erie 



INTO THAT OF LAKE ONTARIO; 



WITH 



Notes on the Origin of our Lower Great Lakes, 



BY 



X W. SPENCER, B.A.Sc, Ph.D., RG.S., 



King's College, IViudsor, N. S, 



[Read before the American Philosophical Society, March i8, iS8i.) 



