Mesozoic and Cenozoic Geology and Paleontology. Al 
meridian. In the same region, on hills 300 feet high, are roches 
moutonnees with their smoothest faces pointing in the same direction, 
or to the northwest. his direction is that of the valley or gorge of 
the Saguenay, which enters nearly at right angles the valley of the 
St. Lawrence. 
In like manner at Murray Bay, there are striz on the Silurian lime- 
stones near Point au Pique, which run about N. 45° W., but these 
are crossed by another set having a course 8. 30° W., so that we 
have two sets of markings, the one pointing upward along the deep 
valley of Murray Bay river to the Laurentide hills inland, the other 
following the general trend of the St. Lawrence valley. The Bowlder 
clay which rests on these striated surfaces, is a dark-colored till, full 
of Laurentian bowlders, and holding Leda truncata, and also Bryozoa 
clinging to some of the bowlders. In ascending the Murray Bay river, 
we find these bowlder beds surmounted by very thick, stratified clays, 
with marine shells, which extend upward to an elevation of about 800 
feet, when they give place to loose bowlders and unstratified drift. 
The Bowlder clay over a large portion of the plain of Lower Canada 
is succeeded by the Leda clay, which varies in thickness from a few 
feet to 50 or perhaps 100 feet. The material of the Leda clay is of 
the same nature as the finer portion of the paste of the Bowlder clay, 
and the latter seems to graduate into the former. It sometimes holds 
hard, calcareous concretions, which, as at Green’s creek, on the Ottawa, 
are occasionally richly fossiliferous. When dried, the Leda clay be- 
comes of stony hardness, and when burned, it assumes a brick red col- 
or. When dried and levigated, it nearly always affords some foramin- 
ifera and shells of ostracoids; and in this, as well as in its color and 
texture, it closely resembles the blue mud now in process of deposition 
in the deeper parts of the Gulf of St. Lawrence. It extends west to’ 
where the Laurentian ridge of the Thousand Islands crosses the St. 
Lawrence, and where the same rocks cross the Ottawa, and in gen- 
eral may be said to be limited to the Lower Silurian plain, and not to 
mount up the Laurentian and metamorphic hills bounding it. 
The Saxicava sand sometimes rests upon the Leda clay, sometimes 
upon Bowlder clay, and often on the older rocks. In some instances 
the surface of the Leda clay has been denuded and cut into deep 
trenches, and the sand rests abruptly upon it; in other cases there is a 
transition from one deposit to the other, the clay becoming sandy and 
eradually passing upward into pure sand. It must have been origin- 
ally a marginal and bank deposit, depending much for its distribution 
