234 'I'he Americnn (ieoloijhf . October, i six} 
Three well marked channels of abandoned outlet rivers were found 
crossing the crest of the " thumb " from east to west. These are called 
the Imlay, Cumber, and Tyre channels, named after villages that are in 
or near them. The last two have their mouths within a mile of each 
other near Cass City. The first channel is farther south, extending 
from near Imlay northwestward to North Branch and probably beyond. 
This channel lies between the head of the great interlobate moraine on 
the southwest and a well defined terminal moraine which is the first in 
a series of three moraines lying between the channel and the present 
lake shore. The Maumee beach of Spencer (probably the same as the 
Leipsic beach in Ohio) was traced from Berville into the head of the 
Imlay channel. The Ridgeway beach, which is the next lower in the 
Warren series, was traced north and east from Emmett to the west slojje 
of the valley of Black river, which lies between the second and third 
moraines. The Arkona beach, next below, also passes northward into 
this same valley. From thepe localities near Port Huron northerly to 
the heads of the Cumber and Tyre outlets the valley has not yet been 
explored. But the fact that the two beaches pass into the valley at the 
south end. while the two outlets pass out of it at the north end, seems 
to leave no serious doubt that the beaches connect with those outlets, 
the Ridgeway with the Cumber, and the Arkona with the Tyre. 
It appears, then, that three stages of lake Warren had their outlets 
westwai-d across the " thumVj " of Michigan to the Saginaw valley, and 
thence westward to the Michigan basin and the Mississippi river: that 
the Forest or last beach of lake Warren is the only one which pas.oes 
around the " thumb;" and that this beach passes into the Pewamo 
channel as the outlet of the lake at that stage. In the Saginaw val- 
ley a new beach was found extending westward from Cass City into the 
Pewamo channel. It lies 20 to 30 feet above the Forest beach, and ap 
pears to have been contemporaneous in its formation with the Ridgeway 
and Arkona beaches. It marks the shore of lake Saginaw, which there 
stood in front of the waning ice-sheet while the third moraine and the 
Ridfreway and Arkona beaches were being formed. This has been 
called the Du Plain beach. 
We have then the following five outlets for as many successive stages 
of lake Warren, namely, the Fort Wayne, the Imlay, the Cumber, the 
Tyre, and the Pewamo. This paper was illustrated by a large colored 
map, showing the several beaches, outlets, and moraines. 
M. Notes on the Glacial Succession in eastern Michigan. F. B. Tay- 
lor. During the author's explorations of the Great Lake region for old 
shore lines, many notes were taken incidentally on the glacial drift and 
its various characters. In 1895 three terminal moraines were clearly 
made out in exploring the eastern coast of Michigan between the strait 
of Mackinac and Saginaw bay. The work of the present season in the 
Sao'inaw valley and on the " thumb " has supplemented that of la.st 
year so as to continue the series down to northern Ohio and Indiana, 
where the moraines had been mapped before by Gilbert and Dryer. If 
to these we add Leverett's moraines in the valley of the Great Miami 
