106 The Aiiierirnn (,Li>i(/(/ist. August, 1895. 
whose wood is found in the intci'j^hicial Toronto beds now 
have their most northern limits in the same region.* 
9. Iroquois stage. Full expansion of the glacial lake Iro- 
quois in the basin of the present lake Ontario and northward, 
then outflowing at Rome, N. Y., to the Mohawk and Hudson 
rivers. Gradual re-elevation of the Rome outlet from the 
Champlain subsidence had lifted the surface of lake Iroquois 
in its western part from near the present lake level at Toronto 
to a hight there of about 200 feet, linally holding this hight 
during many years, with the formation of the well developed 
Iroquois beach. 
Between the times of lakes Warren and Iroquois, the glacial 
lake Lundy, marked by the beach ridge of Lundy's Lane,j- 
probably had an outlet east to the Hudson by overflow across 
the slope of the highlands south of the Mohawk ; but its rela- 
tionship to the glacial lake Newberry, named by Fairchild as 
outflowing to the Susquehanna by the pass south of Seneca 
lake,]; needs to be more definitely ascertained. 
10. St. Lawrence stage. The final stage in the departure 
of the ice-sheet which we are able to determine from the his- 
tory of the Laurentian lakes and St. Lawrence valley is ap- 
proximately delineated on Plate V, when the glacial lake St. 
Lawrence, outflowing through the Champlain basin to the 
Hudson, stretched from a strait originally 150 feet deep over 
the Thousand Islands, at the mouth of lake Ontario, and from 
the vicinity of Pembroke on the Ottawa river, easterly to 
Quebec or beyond. As soon as the ice barrier was melted 
through, the sea entered these depressed St. Lawrence, Cham- 
plain, and Ottawa valleys; and subsequent epeirogenic uplift- 
ing has raised them to their present slight altitude above the 
sea level. 
Later stages of the glacial recession are doubtless recogniz- 
able by moraines and other evidences, the North American ice- 
sheet becoming at last, as it probably also had been in its 
beginnings, divided into three parts, one upon Labrador, an- 
*Am. Geologist, as cited: also Dr. George M. Dawson's letter in the 
July number, pp. 65, 66. 
t'J. W. Spencer, Am. Jour. Sci., Ill, vol. xlvii, pp. 207-211, with map, 
March, 1894. 
^Bulletin, Geol. Soc. of America, vol. vi, pp. 353-374:, with map and 
five plates from photographs of topographic features, April, 1895. 
