274 ETE LOO TRINAL OL GAOL O Ge 
Hinde,’ it has been shown that there is a very important series of 
fossiliferous beds in the vicinity of Toronto, interstratified 
between till sheets. There are two series of fine laminated 
shales and sandstones separated by a sheet of till, with till over- 
lying the whole, and presumably also underlying the whole. In 
the lower stratified series, whose thickness Dr. Hinde gives as 
140 feet, the silts and sands contain organic remains from bottom 
to top. These embrace a considerable variety of forms, the 
most notable of which are the remains of lepidopterous insects, 
all of which have been pronounced by Scudder to be extinct. 
These beds are exposed on the face of Scarborough Heights a 
few miles east of Toronto. Along the river Don, in the imme- 
diate suburbs, Professor Coleman has found a remarkable group 
of molluscan forms and of plants in laminated clays and sands 
that were at first supposed to be equivalent to the fossil- 
iferous series of Scarborough Heights. But Professor Coleman 
informs me that he has reasons for doubting the correctness of 
this correlation, and thinks it not impossible that the beds on the 
Don may correspond to the upper clays and shales in the Scar- 
borough section. If this should prove true (and this statement 
should not be construed as in any way committing Professor Cole- 
man) we shall have here two fossiliferous series requiring cor- 
relation. The series on the Don contain molluscan forms, chiefly 
unios and their relatives, which belong to the Mississippian, 
rather than to the Atlantic, drainage area. They also contain 
plants that indicate a more genial environment than that of 
Toronto at present. From the fact that the molluscan forms 
appear to have passed over the divide between the Mississippi 
and the St. Lawrence basin after the retreat of the earlier ice, 
and to have been subsequently forced out of the basin, presum- 
ably by the return of the ice, which formed the overlying till 
sheet, it has seemed possible, if not probable, that the beds upon 
the Don belong stratigraphically between the Iowan and the 
overlying Wisconsin beds. It will be observed that the grounds 
«GEORGE JENNINGS HINDE: The Glacial and Interglacial Strata of Scarborough 
Heights and other localities near Toronto, Ontario. Can. Jour., April, 1877. 
