THE PLEISTOCENE SUCCESSION NEAR ALTON, 
ILLINOIS, AND THE AGE OF THE MAM- 
MALIAN FOSSIL FAUNA 
MORRIS M. LEIGHTON 
Illinois Geological Survey, Urbana 
Some time previous to 1883 the late Honorable William 
McAdams, an ardent naturalist of Alton, Illinois, collected a num- 
ber of mammalian remains from the Quaternary deposits of the 
Mississippi bluffs near his home city. The specimens found their 
way to the United States National Museum at Washington, where 
they have been studied by Dr. O. P. Hay. The collection includes 
remains of a ground sloth, horse, peccary, a large deer, moose, 
reindeer, eland, musk ox, mastodon, beaver, ground hog, pouched 
gopher, and brown bear.’ Their importance became obvious when 
some of the individuals were found to represent new species, and 
therefore it was especially desirable to ascertain if possible their 
stratigraphic horizon. | . 
The attention of the writer having been called to this collection 
through the kindness of Doctor Hay, arrangements were made 
with the Illinois Geological Survey for a few days’ study with the 
hope of finding the exact locality and horizon, and of determining 
the place of the deposits in the Quaternary series. The deposits 
proved to be so suggestive of new interpretations that this pre- 
liminary paper has been prepared. 
Previous literature.—In 1882 A. H. Worthen noted the finding 
of a portion of the jawbone of a mastodon in the lower part of the 
loess just northwest of the city of Alton.? In 1883 McAdams 
published an abstract of a paper in the Proceedings of the American 
tO. P. Hay, personal communication. 
2 A. H. Worthen, ‘‘ Geology of Madison County,”’ Economical Geology of Illinois, 
Vol. I (1882), p. 252. 
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