35-| The American Geologist. December, 1903. 
Pleistocene History of Northeastern Iowa." published in 1891. 
The cautious, conservative statements of Chamberlin and 
Salisbury scarcely warrant the declaration that they "leave no 
doubt" as to the rluviatile origin of the greater part of the loess. 
Furthermore, at least one of the authors, Dr. Chamberlin, has 
materially modified his views concerning the loess since the 
publication of the work cited. 
The splendid work of McGee, like that of Chamberlin and 
Salisbury a classic in glacial literature, had for its purpose the 
presentation of fundamental facts and conclusions bearing on 
glacial phenomena. If we omit loess from the series of deposits 
discussed therein, the conclusions still remain of great value. 
It is a fact long established that the loess forms a mantle pretty 
uniformly covering the underlying deposits of drift, etc.. espec- 
ially in eastern Iowa, and that, therefore, thr so-called "loess- 
topography" is really drift-topography. If the loess could all 
be removed, the underlying drift would present essentially 
(though not exactly, especially along the Missouri river) the 
topographic features of the present surface. The altitudes of 
the more ' ken regions would be relatively less, as the loess is 
usualh thicker in hilly country. Whatever, then, is prominent 
or striking in the topography of the present surface, was at 
least approximately equally striking in the post-glacial surface 
before loess was deposited upon it. and many of the peculiar- 
ities in the structure and distribution of these underlying de- 
posits were well elucidated by that author, and are in no wise 
affected by dissent with the inclusion of the loess. 
In justice to professor McGee it should also be stated that 
he was misled by erroneous information concerning the fossils 
of the loess, for his inclusion of the loess among glacial or sub- 
glacial deposits was evidently due largely to this fact. Sev- 
eral species which are not only terrestrial, but frequent uplands, 
had been reported as aquatic or semi-aquatic; other species 
were incorrectly identified: and in still other cases conclusions 
d ncerning the mollusks were unwarranted by the facts. 
Some of the earlier reports upon the fossils of the loess 
were inexcusable. Aughey's list of fossils from the loess of 
Nebraska* is impossible. Xo stfch series of shells was ever 
*S.>p Hayden's U. S. Geol. Sur. >>f Colorado and adiacont territory. 1876. 
pp. 266-269; also a practical reprint in Sketches of I'hys. Geog. and Geol. 
of Neb., 1880, pp. 287 290. 
