100 'fhe American Geologist. February, 1895 
but it has been filled in with gravel and sand for two or three 
miles. Much sand has been added to the top of the gravel in 
later times. Some of the modern dunes at the head of the 
bay are nearly 100 feet high, and there are old ones still 
higher, now covered with trees. About a mile east of thebaj" 
on the line of the railroad, there is a little shallow pond called 
Mud lake, which is about 20 or 25 feet above the bay. Its wa- 
ters flow eastward into Round lake which is much larger, but 
still only a small lake. The water then flows into Crooked 
lake, then into Burt's lake, then into Midlet lake and finally 
through the Cheboygan river into lake Huron 18 miles south- 
east of Mackinac. The direction of at least the western part 
of this drainage system was determined by the littoral drift 
of the strong beach referred to. It is doubtful, however, 
whether this particular beach can be traced farther south on 
the facts at present in hand. Traverse City is built upon a 
flat which appears to be an old delta about ten feet above 
the lake. But this shelf is not certainly identified with the 
lower beach at Petoskey. Estimated from its plane at Petos- 
key, Mackinac and Sault Ste. Marie, the beach described 
should pass under the lake at a point ten or fifteen miles north 
of Traverse City. 
Returning to the mainland north of Mackinac, we should 
expect to find this strong beach on the wide terrace north of 
Hessel. But the back of the first terrace against the foot of 
the first steep blutf is about 100 feet above the lake. This is 
considerably too high for identification with the beach of 45 
feet at Mackinac. It seems probable, therefore, that this 
beach rests somewhere upon the surface of the long, sloping- 
stony swamp described in the sixth paper. Although a beacli 
of the same description has not yet been reported between 
Mackinac and St. Joseph and Sugar islands below Sault Ste. 
Marie, there can hardly be a doubt of its identity; it is a part 
of the Nipissing beach, and marks the shore of lake Algon- 
quin. It lies in the same plane and shows the same deforma- 
tions and has the characteristic strength of the Nipissing 
beach farther north. On every ground of comparison its 
identification is complete. 
The West Jfichigan Shore. On the west side of lake Michi- 
gan the Nipissing beach was clearly identified, especially 
