66 



Thk Ottawa Naturalist. 



The fossil remains collected from these beds have shown many 



new forms, and many of them have already been described by Mr. 



Whiteaves the Palaeontologist of the Survey. But apart from the 



palapontological evidence, wliich, so far, is not very definite, the series 



might provisionally be divided under the following heads, on purely 



lithological distinctions. 



Hudson River Shales consisting of reddish and yellowish lime- 

 stones, dolomites and shales. 



Upper Mottled Limestones, Magnesian limestones. 

 Cat Head Limestones, fine grained cherty limestones. (Magnesian.) 

 J.moer Mottled Limestones, very similar to the upper mottled. 

 Winnipeg Sandstones, friable sandstones with shaly bands. 



These several divisions are represented on the accompanying 

 sketch map and section, and are seen to he exposed in regular sequence 

 from the lowest beds on the east, to the highest on the west. The 

 whole formation seems to have a slight dip, south of west which is 

 seen on I /ike Winnipeg very plainly, by following the division between 

 the sandstone, and the overlying limestone beds. This line is quite 

 distinct, and the several measured sections in which it occurs, when 

 plotted, show that the surface of the sandstone or lower face of the 

 limestone, instead of being a plane, is gently undulating or waved, the 

 distance between the crowns of the undulations being from eight to 

 sixteen miles, while the variations in height run somewhere near twenty 

 feet. The direction of the axis of the folds is with the dip towards the 

 W'.S.W., so that the intersections of this crumpled plane, with the hori- 

 zontal one of the lake, forms a waving line, extending from Elk Island 

 northward to near Dog Htad. 



SKETCH Sei ll"\ rHROUGH SiONEWALL, E.N.E., TO HUE WINNIPEG RlVER.* 



The floor on which these rocks were laid is the uneven surface of 

 the Archaean rocks, seen on the eastern side of the lake. In the 



"I'm index >>l shading see sketch map accompanying this paper. 



