JSTorth American Tnterglacial Dejioslts. — Upham. 285 
7. A glacial stajre cliaracterized by moraiiiic ridges of smooth con- 
tour. This stage embraces the final disappearance of the ice-sheet from 
Ohio. A deglaciation interval is believed to have preceded it. but de- 
cisive evidence in support of this view is not obtained. During the 
formation of these later moraines the land had an altitude similar to 
that of to-day. 
The first of these time divisions seems to the present writer 
to be the Kansan stage; the second, the interval between the 
Kansan and lowan stages, including the growth of the forests 
which form the principal interglacial forest beds; the third, 
the time of land depression and retreat of the ice- sheet, with 
deposition of its lowan till and loess, after its lowan stage of 
increased area, the silt in Ohio being contemporaneous with 
the loess in the Mississippi and Missouri valleys; and the 
fourth to the seventh, successive parts, comparatively short, 
constituting together the Wisconsin or closing stage or epoch 
of the Ice age in the northern United States, according to its 
subdivision proposed by Chamberlin. The depth of the leach- 
ing by which the calcareous matter of the interglacial soil and 
subsoil in Ohio and westward was removed during the inter- 
val between the Kansan and lowan stages is found by Mr. Lev- 
erett to be seldom less than six or eight feet, while the pres- 
ent soil is rarely leached to so great a depth as six feet. In 
both cases the measurements are in till of closely similar 
character. An earlier paper by Mr. Leverett* gives the dis- 
tance of the interglacial recession known by this ancient soil 
and the accompanying forest bed as not less than 250 miles to 
the north from the southern margin of the drift in Illinois, 
and nearly 150 miles to the north from the outermost mo- 
raine of the newer drift. 
Toronto and Scarboro, Ontario. — An excavation in the strat- 
ified drift and till for brick-making beside the Don river in 
the suburbs of Toronto, on the northwest coast of lake Onta- 
rio, recently described by Prof. A. P. Coleman, f has yielded 
many fresh-water raollusks and wood of three species of trees. 
The mollusks, as determined by Dr. W. H. Dall and Mr. C T. 
Simpson of the Smithsonian Institution, comprise Pleurocera 
*Proc., Boston Society of Natural Historv. vol. xxiv, pp. 455-459, Jan. 
1, 18!)0. 
fAM. Geologist, vol. xiii. pp. 85-!)."). Fib.. 1894. The following dis- 
cussion of this i>aper was contributed to the Glacialists' Magazine, vol. 
I, pp. 2:56-240. .lune, 1894. 
