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bed and soil are terms which are used interchangeably in the Ohio Geological Reports. It ought also to be stated in this connection that a few miles to the north a buried soil occurs beneath the till, but it lies within the district covered by a later invasion of the ice, and the horizon is, I am convinced, above that of the one in question. There is also a soil above the yellow till of this earlier drift sheet which is buried by a silt deposit, as described below. I feel, therefore, that it is necessary to refer to different horizons the instances that have been reported from south-western Ohio.

Deglaciation interval with development of a soil attended by oxidation, leaching and erosion of the earlier drift sheet. Except where erosion has removed it a capping of silt several feet in thickness is found upon the surface of this till sheet. It is clearly of much later age than the till, being separated from it by a sufficient interval for the development of a soil, and for a large amount of oxidization and leaching and erosion. This silt is discussed below.

The soil which was developed on this till sheet does not commonly show a black color, though exposures of such a soil color are met with in all parts of the district outside the outer moraine. The evidence of a land surface is more generally found in the deep brown color, and weathering or soil-producing disintegration of the upper part of the till. The deep brown changes gradually below to the ordinary yellow color of oxidized till, but at top it terminates abruptly at the base of the overlying silt. The color of the silt being much lighter than that of this brown soil the contrast is very marked. The deep brown color extends usually to a depth of two feet or more, while discoloration extends six or eight feet. The amount of discoloration is somewhat greater than is commonly found at the present surface of the newer drift. Repeated comparisons of the soil in the two districts lead to the conviction that this older drift sheet had been exposed as a land surface for a longer time before the silt was laid upon it than has the outer moraine of the newer drift up to the present date. The same conclusion is reached