Review of Recent Geological Literature. 11* 
In this volume of the memoirs of the Peter Redpath Museum of McGill 
University, Montreal, this distinguished author and veteran geologist 
has collected and restated his views regarding the Ice age as it occurred 
in Canada. As is well known to all glacialists, Sir William Dawson has 
always demurred to accepting the prevalent theory— the Agassizian 
theory, as it may be termed — of a continental glacier, and has instead 
thereof steadily insisted upon the doctrine that the glacial phenomena 
of Canada, at least, may be satisfactorily explained by the action of 
local glaciers and of heavy floe-ice. Geologists who were present at the 
Montreal meeting of the American Association for the Advancement of 
Science will recall the ability and earnestness with which he defended 
this position against all assaults, and the courtesy and kindliness which 
marked all the discussions in which he played the double part of host 
and antagonist. 
After a brief review of his earlier published writings on this subject, 
the author takes up the task which he has assigned to himself and be- 
gins with a description of the Pleistocene formations in eastern Canada, 
which are as follows, in descending order: 
Terraces and Inland Cliffs. 
The Saxicava sand. 
The Leda clay. 
The Boulder-clay. 
In this series the boulder-clay constitutes the true "till," a hard, gray 
clay tilled with stones and thickly packed with boulders. It rests for 
the most part on smoothed or striated rock surfaces, and is in some 
places on the lower St. Lawrence fossiliferous, holding Leda glacialis 
(Yoldia arct tea Gray), and stones covered with Balanus hameri and 
Polyzoa, indicating marine conditions of deposit. It contains also great 
quantities of loose boulders, both of local and of distant origin. 
The striation of the underlying rock is for the most part in a N. E.- 
S. W. direction; but in some spots, as in the Mile-end quarries near 
Montreal, the surface shows four sets of striae, while very frequently 
two sets can be found at right angles to one another, of which in east- 
ern Canada the' N. E. — S. W. group is, for the most part, on the lower 
ground, whilethe N. W.— S. E. group is usually higher. The former the 
author attributes without hesitation to the Arctic current passing up 
the valley during a time of submergence, and the latter in general to the 
local glaciers which more or less filled the lateral valleys, such as those 
of the Saguenay. Murray bay, and the Ottawa river. At the mouth of 
the former are grooves on a magnificent scale, some being ten feet wide 
and four feet deep, being cut into hard gneiss. 
To enable ice floes carrying stones to reach the high levels at which 
striation occurs, a depression of the land is assumed, which converted 
the St. Lawrence into an arm of the sea and left only the high 
est points of the Laurentides and Appalachians above the water, thus 
allowing a vast arctic current to How over thecountry of the great Lan- 
rentian lakes. 
The Leda clay, which constitutes the subsoil over ;i large portion of 
