THE 
AMERICAN GEOLOGIST 
A MONTHLY JOURNAL OF GEOLOGY 
ALLIED SCIENCES. 
Editor: N. H. WIXCHELL, Minneapolis, Minn. 
ASSOCIATE EDITORS: 
Florence Bascom, Bryn Mawr, Pa. 
Charles E. Beecher. New Haven, Conn. 
Samuel Calvin, Iowa City, Iowa. 
John M. Clarke, Albany, N. Y. Ulysses S. Grant, Evanston, III. 
Herman L. Fairchild, iJocfiester. AT. F. Oliver Perry Hay, New York,X. Y. 
Persifor Frazer, Philadelphia, Pa. George P. 'Merrii^-l, Washing-ton , D. C. 
Warren Upham, St. Paul, Minn. 
Israel C. White, Morg^antown, TV. Va. 
Horace V. Winchell, Butte, Mont. 
VOLUME XXX 
July to Deckmjjer, 1902 
Minneapolis, Mlnn. 
The Geological Publishing Co. 
1902 
TlIK llMVRKSITY PRESS OF MINNESOTA. 
