420 
GLACIAL GEOLOGY 
do not actually display well an older drift sheet are no reflection 
on the trustworthiness of McGee’s observations; nor do they 
miltitate in any way against the correctness of the McGee con¬ 
clusions. Inference from Lees’ argument is that the loess does 
not separate two drift sheets, and that “there is no trace of a drift 
beneath the loess.” Lees’ observations are manifestly faulty, 
partial and essentially superficial in the extreme, and his conclu¬ 
sions are necessarily forced and without warrant. 
It so happens that the McGee sections on Capitol Hill are not 
isolated ones, on the interpretation of which must stand or fall 
the verity of his records. McGee gave other sections in the 
neighborhood and on the west side of the Des Moines River which 
display clearly identically the same phenomena. 
But the McGee observations have another and very recent and 
complete verification. On West Hill, in Des Moines, extensive 
grading on Fifth Street, north of Grand Avenue, display superb 
sections showing the loess separating the two drift sheets (plate 
xxxvii). Moreover, at the very lowest part, in protected depres¬ 
sions, appear to be remnants of a third and still older till, which 
may prove to be the Nebraskan drift. So, even after almost half 
a century, McGee’s once startling records are indisputable sub¬ 
stantiated. Ke;ye;s 
Permian Glacial and Continental Deposits in Argentina. Cur¬ 
rent maps of Permian formations, as for example that published 
by Schuchert in his Carnegie Institution paper on climate and 
reproduced in his Historical Geology, show no glacial deposits in 
the Argentine, although scattered areas of supposed Permian till 
have long been known. Most of the literature dealing with these 
Argentine Permian till deposits has been in the Spanish language 
and has been published in official or other publications of the Re¬ 
public. It is apparent that little of it is known to students in 
general, although the publications of the Argentine Survey, the 
Museums of La Plata and Buenos Aires, and the National Acad¬ 
emy, at Cordoba, are most meritorious and rank easily with similar 
publications of other countries. 
Quite recently Keidel ^ in a memoir entitled “Sobre la Distri- 
1 Bol. Acad. Nac. de Ciencias en Cordoba, tomo XXV, pt. 3a, 1922. 
