Devonian Era in the Ohio Basin. — Claypolc. 105 
brought in, while the finer detritus was carried out into the gulf 
and laid down as off-shore deposits. 
A word should be said regarding the two conglomerates, 
the Allegrippus and the Lackawaxen, which figure conspicu- 
ously in the outcrops of the Chemung from Virginia to Xew 
York, but which do not appear farther to the southeast in cen- 
tral Pennsylvania. These assume considerable importance in 
consequence of the identification of the latter with the first, and 
of the former with the third, oil sands of Venango county, as 
was done by professor White. These conglomerates apparently 
border .the northern shore of the gulf and may be the products 
of erosion from that quarter. But, if not, their presence need 
create no difficulty greater than that which is involved in the 
presence of the later and heavier Carboniferous conglomerates 
in the same region and over a wider area, whose materials 
nevertheless, came undoubtedly from the east. The greater 
problem, when its solution is attained, will explain the less. 
Peculiar conditions whose beginnings are apparent in these 
Chemung conglomerates must have rendered possible the trans- 
fer of so vast a mass of pebbles along the northern margin of 
the Appalachian gulf, but the problem belongs rather to Car- 
boniferous than to Devonian geology. 
GLACIAL LAKE NICOLET AND THE PORTAGE 
BETWEEN THE FOX AND WISCONSIN RIVERS. 
By Warren Upham, St. Paul, Minn. 
Two years ago I spent two months of the summer in a 
journey east through the older states, to the Atlantic coast and 
New England, visiting many libraries and museums, for obser- 
vations concerning the expected removal of the Minnesota His- 
torical Society to the new state capitol. 
Incidentally, opportunity was afforded for geologic exam- 
ination and study of several localities that are of special ink-r- 
est in their relation to the great glacial lakes held by the bar- 
rier of the waning ice-sheet on the northern borders of the 
United States, belonging thus to a part of the Champlain 
epoch or closing stage of the Glacial period. Two of these 
studies were soon afterward published in the American Ge- 
