Postglacial Submergence east of Georgian hag. — Taylor, 275 
well marked just above the main road for two or three miles 
north of the town. It is nearly as prominent in the town 
itself, and may be seen to good advantage on West, Coldwater 
and Penetang streets, and in several other places. Toward the 
south the ancient coast line becomes deeply indented by a 
valley, and into this the shore line gradually fades awaj'. 
During the second visit to this place I drove to McDon- 
ald's hill, about two miles northeast of Atherty, a village 
which is about two miles east of Orillia, on the opposite side 
of the river. This hill is about 85 feet above the lake and its 
crest, which is a wide, bouldery beach ridge, extends in a 
northeast and southwest direction, and appears to have been 
heavily washed by waves. Extensive excavations have been 
opened in the western slope of the hill near its top for ballast, 
and they show its composition to be almost entirely of lime- 
stone boulders of small size, and grading from this down to 
the fineness of coarse sand. The quantity of small boulders or 
cobbles of a diameter averaging from four to eight inches is 
enormous. All the material is thoroughly rounded. The hill 
faces northwestward over lake Couchiching and the valley of 
the Severn river, toward Georgian bay. This hill is not quite 
high enough to record the highest beach, and there is no higher 
ground on that side of the river within a distance of six miles 
or more. The altitude of the beach in Orillia, measured at the 
back of the terrace in the town, is about 110 feet above lake 
Simcoe, or 830 feet above the sea level. Both here and at 
Barrie we explored the higher ground without finding any 
evidence of submergence. 
Lorneville. In going from Orillia to Lindsay the Algonquin 
beach was again crossed at a point about a mile and a half 
west of Lorneville. At this place a series of well formed, but 
rather low and light sandy beach ridges rests upon an open 
country, sloping gradually toward the southwest. The upper 
ridge is about 815 feet above sea level, and appears to mark 
the upper limit of postglacial submergence. 
Midland. At a point about two miles and a half south of 
this place the highest shore line was found very plainly de- 
veloped against the north and easl face of a high hill, at as 
altitude of about 820 feet above the sea. Between the town and 
this locality fragments of beaches were observed in two or 
