490 8. V. Wood,jun. — American and British Surface-Geology. 
generally of conditions as frigid as those wliicii prevailed during the 
first glaciation. On the other band, if there never was anything 
rnore than such a limited depression of the St. Lawrence basin as 
sufficed to bring the Atlantic waters over those parts which are 
covered by the Leda, Champlain, and other marine clays of the coast 
districts (and I fail to see how there could have been more), we 
should not find this explanation of difference in level available as 
an explanation, but be driven to infer that the glaciation to which 
the beds overlying the forest-surface were due was a minor one ; so 
that the ice did not reach to its former position, but damming up the 
lower valley of the St. Lawrence (which lies in several degrees higher 
latitude than Ohio), it filled the lake-basin withthe waters produced 
by its dissolution, over which drifted the ice from whose droppings, 
and from the mud and gravel taken up by currents from the glacier 
discharge, these beds appear by Prof. Newberry’s description to be 
made up — beds which possess very much the physical character of 
the Contorted Drift of Cromer, without its included marl masses, as 
well as of the purple clay of the district near Flamborough Head 
which is shown in the sections accompanying the sequel of this 
paper under the letter d. 
3. The beds thus overlying the forest-surface in Ohio consist, 
according to the Professor, of clays, sands, and gravels of various 
kinds, sometimes containing boulders as well as having boulders 
extensively scattered over them. These beds, to which I have already 
referred under the Symbol 3a, he considers were deposited by the 
lake-waters while the Canadian highlands were occupied by glacier- 
ice, from which bergs breaking otf drifted over the lake-basin and 
scattered blocks. 
Looking at the general group of facts affecting the American 
region as described by Prof. Newberry, and at the general facts with 
which a long study of the English beds have made me familiär, I 
strongly incline to the belief that both in America and in Europe 
there have been two glaciations only ; one, the greater, during which 
the beds that I term glacial were accumulated, and when Britain 
underwent its general submergence; and the other, the less, which 
was subsequent to the general emergence of this country, but oc- 
curred while the South of England was still partially submerged, and 
the North of England and South of Scotland had undergone partial 
resubmergence, and during which the older part of the beds that I 
term post-Glacial were accumulated. I think that if we take into 
consideration the greater height of the glacier generating land in 
Britain over that in Canada, this minor glaciation bears the same 
proportion to the inajor in both countries ; for the Canadian high- 
lands forming the northern lip of the St. Lawrence basin, and on 
which, according to Prof. Newberry, the ice terminated and sent off 
its bergs during the accumulation of the beds 3a, lie between 
latitude 45° and 50°, which is at least 5° of latitude short of that 
to which the grooved rock-surface of Ohio shows the glacier-ice 
giving rise to the Erie clay had reached. In Britain there is not 
this difference in latitude between the limits of the major and minor 
