A Form of Outwash Drift 
49 
retreat of the ice in this region. It is evident also that this wide 
band of moraine represents more than the decay of the ice reach- 
ing out from the Ontario lobe into Seneca valley. It more likely 
is an indication of the general northwest trend of the ice-front 
crossing Flint, Naples, and Canandaigua valleys. When the ice 
Fig. I. A part of the Penn Yan (N. Y.) Quadrangle. 
Stood with a reentrant angle approximately at Milo Center, the 
Seneca tongue reached many miles southward towards Watkins, 
while the lesser lobe in the Keuka valley was shorter. A detail of 
this lesser lobe evidently would give two tongues of ice, one occupy- 
ing each arm of Keuka lake, with the reentrant angle along the 
