198 The Aincrican Geologist. March, i8f8 
cm point, and, after expanding into a small lake at the head of the 
Saginaw Bay basin, to have entered Grand river along what has been 
termed by Spencer the Pewanio outlet. Mr. Taylor's studies, as 
well as mine, sustain the interpretation that the eastern and northern 
boundaries of the lake were found in an ice barrier, and they apparently 
bring out more clearly than mine the relationship of the ice to the lake. 
It remains to speak of the results of Prof. Fairchild's studies of the 
extent of lake Warren in western New York. The beach marking the 
upper limit of that lake (called by the writer the Crittenden, but prob- 
ably the equivalent of Spencer's "Forest beach") has been traced east- 
ward, from the supposed termination near Indian Falls, beyond the 
Genesee river. The eastern terminus is at present unknown. As at 
Cleveland, the beach is less well defined east from the supposed correla- 
tive moraines than west from them, vet there appears to have been more 
wave action in the portion discovered by Prof. Fairchild, than in the 
case of the Leipsic beach in the east part of Cleveland. The wave ac- 
tion is sufificiently marked to have attracted my attention, though no 
beach was noted in connection with it. This is set forth in the fol- 
lowing statement taken from my paper in tlie American Journal of 
Science (pp. 18-19) : 
"Upon examining the district eastward from northwestern Gene- 
see county (where the Lockport moraine and the Crittenden beach 
intersect), we found a narrow belt at about the level of the Crittenden 
beach where the drift forms seem'to have been somewhat modified by 
the action of waves or currents of water. This is considered a possible 
lake level, or perhaps a lake outlet. There is a large amount of grav- 
elly drift in this belt, but so far as discovered it is not arranged in beach 
lines, the surface being either plane or having a gentle undulation, as 
if the drift knolls had suffered reduction or modification by waves or 
currents. This gravelly drift occupies usually a breadth of two or three 
miles. In places it occupies the entire interval between the Lockport 
moraine and the drumlin belt which lies north of it." 
Concerning the views expressed in my paper. Prof. Fairchild makes 
the following remarks (page 271) : 
"Some of the views guardedly expressed in that article are definitely 
confirmed, while others require modification. The Lockport moraine 
was, undoubtedly, the eastern limit of the Warren water for a con- 
siderable time, and correlates with the formation of the beach south of 
Crittenden. But the withdrawal of the ice-front from that portion did 
not produce immediate lowering of the water or terminate the beach- 
making process at the Crittenden level. The zone of sand and gravel 
drift described by Mr. Leverett as lying north of the Lockport moraine 
is the shore deposit of the enlarged lake, and is definitely bordered by 
the eastern extension of the beach. 
"A comparison, as regards the time involved, of the beach east of 
Indian Falls, with the beach westward, is very difficult to make on 
account of the difference in the topographic relief. The Crittenden 
