14S THE CANADIAN NATURALIST. [Vol. X. 



In Canada many streams cut throimh the locks of the region 

 •under consideration, and give fine exposures of their geological 

 structure. The streams invariably excavate picturesque glens, 

 nt the head of which are usually cascades in magnitude from the 

 Falls of Niagara to others forming a mere series of rapids. 



Develojwient — The best exposures of the Niagara formation 

 in the State of New York are at Lockport, Rochester and Nia- 

 gara River. It attains a thickness of 264 feet in that State. In 

 Canada the upper portion of the scries is so denuded in the 

 neighbourhood of Lake Ontario, that it is impossible to get a 

 •complete section ; and even many miles away where it passes 

 into the overlying Guelph formation, as near Rockwood tht line 

 of junction is generally obscured by drift. 



At Hamilton, by level measurements, a section of the lower 

 52 feet (being beds from 7 to 12 of Section III) was made by 

 Mr. S. D. Mills and myself, between the exposure at the head of 

 James street and the "Jolly Cut'' road, a half mile to the 

 cast. Here the escarpment averages i-iOO feet in height above 

 tiie lake. The cherty dolomites (No. 12 of Sections) form tiie 

 capping stratum of the "Mountain." Along the Sydenham 

 road (section II), the section, composed of the same beds, 

 measured 60 feet (seven feet more of the •• Chert bed " is ex- 

 posed here than at Hamilton). Again, at the junction of Glen 

 Spencer with Glen Webster, the same •• Chert beds " ibrui the 

 capping stratum of the cliffs, and here the Niagj'ra beds are 

 a little thicker than elsewhere. However, on the eastern side of 

 these ravines there is an additionrd exposure of 104 feet near the 

 *' Peak," which has not been removod by denudation, thus giv- 

 ing a maximum thickness of 169 feet at Dundas. However, by 

 measuring the section at Albion Falls, and then levelling up 

 Kosseaux Creek and alons: the strike of the formation to Car- 

 penter's Limekilns, on Lot 15, and Ranoe VI, Barton, two miles 

 south of the brow of the " Mountain," at Hamilton, I succeeded 

 in measuring a section of 198 feet from the base of the Niagara 

 (proper). The height of the last station is 480 feet above the 

 lake, and in addition the rocks are covered with five feet of soil, 

 at the Church, on the same lot. Here the rocks have their 

 surfaces grooved with ice action. It may be remarked that the 

 capping bed in this place is almost wholly made up of the 

 remains of Stromatopora. 



