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50 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
wall. One of the best defined ridges, at an elevation of twelve hundred 
feet, is from twenty to fifty feet high and some four hundred yards in 
length. The longitudinal and transverse profiles are in every way similar 
to those of a Swiss lateral moraine. Though generally arranged parallel 
to the valley-wall, in some instances the moraine is winged out from it 
and is then characterized by many shallow kettles and small ponds. The 
general slope of the moraine-crests is to the southward toward Nachvak 
Bay, and is sympathetic with the inclination of three well-marked rock- 
benches on the east side of the Kogarsuk Valley. Combining the evi- 
dence of groovings with these facts, it was evident that the glacier that 
was responsible for the moraines and benches flowed southward toward 
Ficure 3.— Cross-section of the Kogfrsuk Valley showing its bed-rock floor overlain 
by lateral moraines (solid black) and trenched ground moraine (dotted lines). Rock- 
benches on the right. Looking north. 
KAPUTYAT MT 
LIMIT OF GLACIATION 
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Kogarsuk Brook 
the great fiord. At twelve hundred and fifty feet on the flat top of the 
long spur which lies in the angle between the fiord and the brook, a 
crescent-shaped frontal moraine nearly four hundred yards in length 
lies, as it were, stranded there, as the Kogarsuk glacier retreated to its 
narrower channel on the east. 
The belt of lateral moraines, here and there broken down in the 
paths of entering side streams, extends five miles to the northward from 
its southern extremity. A little more than three miles from the 
mouth of the brook, the valley widens out in a notably flat stretch 
estimated to be at least eight miles in length and from one to three miles 
in width. The bed-rock is here deeply buried in a till-deposit which 
seems to be transitional into the terraced lateral moraines on the west 
