 The occurrence of a lake at this level in Algonquin time makes this beach a part of the Algonquin beach of the upper Great Lakes region.The Algonquin beach carries in a few places molluscan shells, and this beach of Lake Chicago is in places richly supplied with these shells.In this respect it contrasts with the Calumet and Glenwood beaches, from which molluscan remains have as yet been reported at but one locality, near Bowmanville, north of Chicago.