Review of Recent Geological Literature. 123 
and kames were formed chiefly or wholly from drift borne along beneath 
the ice, and in the case of the sand and gravel osar and kame deposits 
further transported and heaped up in their present forms by subglacial 
streams. Among the materials of kame hillocks, incorporated masses 
or tongues of typical till of the ground-moraine type have been observed, 
with gradations from them to partially modified masses and layers, half 
of till and half of gravel, and to completely assorted and stratified 
gravel and sand, thus showing every stage of derivation from the under- 
lying and surrounding till. The view assumes that the amount of en- 
glacial drift was too scanty to yield these deposits, and that all or nearly 
all the drainage of the departing ice-sheet found its way through 
crevasses and moulins to the ground. It seems very difficult, however, 
under these conditions to account for high osar or esker ridges, like 
that of the Pinnacle hills near Rochester, X. Y., 100 to 200 feet above 
the surrounding nearly plane surface, yet containing throughout all 
their mass, quite to their top, plentiful large and small boulders and 
gravel which in that instance were derived from ledges within a dis- 
tance of no more than three or four miles northward. These hills and 
other eskers and kames presenting similar characters must apparently 
have been formed by streams flowing down from the melting ice-surface 
and gathering its englacial and finally superglacial drift in open ice- 
walled channels. Thedrumlin observed in Wisconsin and mentioned as 
resting on and enveloping a knob of peculiar quartzite may have been 
deposited in the manner supposed by Upham in his paper in the last 
December GEOLOGisT,in which case its accumulation would necessarily 
be attended with much abrasion of the knob and incorporation of its 
fragments in the drumlin mass. This essay and many others which 
have lately appeared seek for explanations of the manner of drift trans- 
portation and deposition, that is, of the genesis of our drift formations; 
and two diverse working hypotheses, one believing the englacial drift to 
have been plentiful, the other that it was of small amount, lead to 
somewhat unlike interpretations for these and for nearly all our other 
drift deposits. Meanwhile, to this and all questions concerning the 
history of the Ice age, much light is being brought by the explorations 
of the Malaspina glacier and the Greenland ice-sheet; but the condi- 
tions attending the closing stages of the Pleistocene glaciation were 
doubtless in some respects widely different from those of the now ex- 
isting ice-sheets of arctic and antarctic lands. 
The Finger Lakes of New York. By Albert P. Brigham. pp. 21. Re- 
print from Bulletin of the American Geographical Society, vol. xxv, 1893. 
The region of the Finger lakes in the south central part of New York is 
regarded as a plateau extending from the Catskill mountains to the 
Genessee river, with its summits about 2,000 feet above the sea and 
much of its general surface above 1,000 feet. The mairj watershed of 
this plateau extends from east to west with slopes descending from it, 
one northward to lake Ontario a ad the Mohawk, the other southward, 
bearing the head streams of the Susquehanna. Upon both faces of 
this east and west ridge or plateau and extending across the divide, is 
