434 
Frank Carney 
the lines induced by gravity. While only one esker (fig. i8) has 
been mapped in this region, it is nevertheless possible that some 
of the short and isolated ridges of washed drift do represent seg- 
ments of subglacially aggraded drainage lines. It is this associa- 
tion that prompts the above suggestion concerning the genesis of 
some of the erosion channels noted in the area. 
(3) Just a few rods east of the third road to the left going south 
from Como is a deserted water course which has no connection 
with recent drainage; its proportions are entirely out of harmony I 
with the work that might be done by the waters assembling from jl 
the catchment basin to which the channel is contiguous; it is || 
direct in course, leading southward, and plainly has the marks j 
of vigorous initial development. i 
(4) East of Sempronius the thickened drift indicates a long | 
halt of the ice. Extending southward from this area, in which | 
Fall Creek now heads, are several clean cut channels indicating 
the work done by ice-front drainage. 
(5) In the region of thickened drift north of North Lansing I | 
have also observed waterways that obviously are not due to post- I 
glacial erosion. I 
Ice-Walled Channels. | 
Gilbert^’ and Fairchild^® have described the peculiar terraces 1 
and benches produced by water courses, one wall of which was j 
the ice in position. The recent work of Fairchild in the Mohawk | 
valley^® calls attention to a variety of such water courses. I 
A few instances of these ice-walled channels are noted on the | 
Moravia quadrangle. The development attained is not marked l| 
since in the higher altitudes of this sheet no water bodies persisted >! 
any great length of time. Where a rock slope abutted the ice, | 
and the ice fed around this slope in either direction, the topography j 
otherwise forming the conditions for ponded waters on either side, 
then as the ice retreated the water on one side or the other would 
coalesce or flow down into the other body. The channel through 
which the water spilled consisted of rock on one side and ice ' 
on the other. If the ice were permanent for some time, normal . 
Bull. Geol. Soc. Am., vol. 8 (1897), p. 285. 
N. T. State Mus., 22nd. Rep. of State Geologist (1902), pp. r23-r30. 
Ihid., 2 lstRep. of State Geologist (1901), pp. r35-r47. 
