THE 
AMERICAN GEOLOGIST 
A MONTHLY JOURNAL OF GEOLOGY 
AND 
ALLIED SCIENCES. 
Editor: N. H. WINCHELL, Minneapolis, Minn. 
ASvSOCIATE EDITORS: 
Florence Bascom, Bryn Mawr, Pa. 
Charles E. Beechek. iVew .ifavca, Conn. 
Samuel Calvin, Iowa City, Iowa. 
John M. Clarke, Albany, N. Y. Ulysses S. Grant, Evanston, III. 
Herman L. Fairchild, i?oc/jester,Ar. y. Oliver Perry Hay, New York,N. Y. 
Persifou Frazer, Philadelphia, Pa. Georgb P. Merrill, WasA/u^ton.D.C. 
Warren Upham, St. Paul, Minn. 
Israel C. White, Morgantown, W. Va. 
Horace V. Winchell, Butte, Mont. 
VOLUME XXXI 
January to June, 190?} 
Minneapolis, Minn. 
The Geological Publishing Co. 
1903 
The University Press of Minnesota. 
