78 THE CANADIAN NATURALIST. [Vol. X. 



The following is Dr. Spencer's summary of the whole paper : 

 1. The Niagara escarpment, after skirting the southern shores 

 of Lake Ontario, bends at nearly right angles in the neighborhood 

 of Hamilton, at the western end of the lake ; thence the trend is 

 northward to Lake Huron. At the extreme western end of the 

 lake this escarpment (at a height of about 500 feet) encloses 

 a valley gradually narrowing to four miles, at the meridian of 

 the western part of the city of Hamilton, where it suddenly closes 

 to a width of a little more than two miles, to form the eastern end 

 of the Dundas valley (proper). This valley has its two sides 

 nearly parallel, and is bounded by vertical escarpments, which 

 are capped with a great thickness of Niagara limestone, but 

 having the lower beds of the slopes composed of Medina shales. 

 On its northern side the escarpment extends for six miles to 

 Copetown ; westward of this village it is covered with drift, but 

 it is not absent. On its southern side the steep slopes extend for 

 less than four miles to Ancaster, where they abruptly end in a 

 great deposit of drift, which there fills the valley to near its 

 summit, but which is partly re-excavated by the modern streams, 

 forming gorges from two to three hundred feet deep. To the 

 north-eastward of Ancaster these gorges are cut down through 

 the drift to nearly the present lake level. 



Westward of Ancaster, a basin occupying a hundred square 

 miles, where the drift is found to a great depth, forms the western 

 extension of the Dundas valley. With the north-western and 

 western portions of this drift-filled area the upper portion of the 

 Grand River and Neith's Creek were formerly connected. The 

 Grand River, from Brantford to Seneca, runs near the southern 

 boundary of this basin, then it enters its old valley, which extends 

 from Seneca to Cayuga, with a breadth of two miles, and a depth, 

 in modern times, of seventy-five feet, having its bed but a few 

 feet above the surface of Lake Erie. Near Cayuga, the deepest 

 portion of the river-bed is below the level of Lake Erie. 



2. The Dundas valley and the country westward form a por- 

 tion of a great river valley^ filled with drift. Along and near its 

 present southern margin this drift has been penetrated to 227 

 feet below the surface of Lake Ontario, thus producing a canon 

 with a lateral depth of 7'13 feet, but with a computed depth, in 

 the middle of its course, of about 1000 feet. 



3. The Grand River, at four miles south of Gait, has since 

 the Ice Age^ left its ancient bed, which formerly connected with 

 that of the Dundas valley, as did also Neith's Creek, at Paris. 



