> 
’ 
ADDITIONAL NOTE ON DRIFT FRESH-WATER SHELLS. 497 
useful, in the accompanying tabular view, which is by no means pro- 
posed as exhausting the varieties of fruits, but will at least sufficiently 
explain the principles upon which, I conceive, they ought to be studied. 
ADDITIONAL NOTE ON THE OCCURRENCE OF FRESH 
WATER SHELLS IN THE UPPER DRIFT DEPOSITS 
OF WESTERN CANADA. 
BY E. J. CHAPMAN, 
PROFESSOR OF MINERALOGY AND GEOLOGY IN UNIVERSITY COLLEGE, TORONTO. 
In a recent number of this Journal, I published a series of Notes 
on the general conditions of occurrence of the Drift deposits of Upper 
Canada, in which I strove to establish, more especially, the former 
extension and union of our great lake-waters. Amongst other facts 
tending to this view, I cited examples of the occurrence of fresh- 
water shells, identical with those of our existing lake-species, in some 
of the higher Drift-beds, as discovered respectively by Mr. Robert 
Bell of the Geological Survey ot Canada, by Dr. Benjamin Workman, 
of Toronto, and by myself. I have now to add to the localities there 
cited, one of still higher interest in its bearings on this question, as 
it discloses, over a considerable area, an extraordinary abundance of 
fresh-water shells belonging to seven distinct genera. This locality 
was discovered and made known to me by one of my former students, 
Mr. A. E. Williamson, at present engaged on the Northern Railway 
of Canada. It lies around the Nottawasaga river, in the vicinity of 
the Angus Station of that railway. The shells, at least, are more abun- 
dant or best seen at this spot, but I have traced them over a distance 
of four miles south of Angus Station, and I havejalso found them to 
extend a mile or more in other directions. In all probability, 
however, they will be met with much beyond these limits, as my visit 
to the spot was a hurried one, and made during a day of extreme heat. 
They lie in fine sand, at various depths below the surface of the ground, 
varying, at the points examined, from about a foot to ‘sixteen or 
eighteen feet, according to the surface inequalities of the district. 
Those at present collected comprise species of the following genera : 
Unio, Cyclas, Amnicola, Valvata, Planorbis, Limnea, and Physa. The 
