The study of the lacustrine history of the Genesee valley was undertaken in continuation of the work upon the glacial lakes in western New York* and with no expectation of making it the subject of a separate paper. The history is found, however, to be of remarkable and romantic character. The glacial waters alternately flowed to the gulf of Mexico and to the Atlantic ocean direct. Five great river systems received the overflow at different periods, namely, Ohio-Mississippi, Susquehanna, Illinois-Mississippi, Hudson, and Saint Lawrence.
The phenomena are complex and singularly interesting, and the determination of the several water-levels, involving the facts concerning the nature and sequence of the geologic events, reveal a fine problem in glacial geology which is thought to have been solved in its general features. A vast body of interesting details remains unstudied.
The work upon the region was done in the late autumn of 1894 . . .