WE will begin the critical discussion of the views
set out in Köppen and Wegener's book, " Die
Klimate der geologischen Vorzeit," with some
further analysis of the climatic conditions during the
Upper Carboniferous period, beginning with the United
States, the British Isles, and Central Europe. According
to the " drift " theory, these coal beds represent a luxurious
tropical rain-forest, and the equator is therefore drawn
as nearly as possible through the middle of them. The
evidences of glacial action which have been adduced
from time to time in close proximity, both in space and
time, to these coal beds are dismissed out of hand as not
genuine. The American evidence, however, seems to
be too well founded to be dealt with in this summary
fashion. Thus S. Weidmann (I) describes conglomerates
of Upper Carboniferous to Permian age in the Arbuckle
and Wichita Mountains of Oklahoma and in Kansas,
associated with all the paraphernalia of glaciation—
scratched boulders, erratics, fluted and polished floors,
and U-shaped valleys. Some of the boulders in marine
deposits have apparently been carried by icebergs, and
the author attributes the phenomena to islands in the
Late Palæozoic sea bearing local valley glaciers. J. A.
Taff (2) found boulders up to 20 feet across and 5 or
6 feet thick, 50 miles or more from their source, in the
marine Caney shales of Eastern Oklahoma. " No other
competent means of their transportation than ice
—presumably heavy shore ice—has been suggested. "

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