THE / 
American Geologist 
A MONTHLY JOURNAL OF GEOLOGY 
AND 
/ 
ALLIED SCIENCES. 
EDITORS AND PROPRIETORS: 
Samuel Calvin, Iowa City, Iowa. 
John M. Clarke, Albany. N. Y. 
Edward W. Claypole, Akron, Ohio. 
Francis \Y. Cragin, Colorado Springs, Colo. Robert T. Hill, Austin, Texas. 
John Eyerman, £(Hfo», Pi;. Joseph B.Tyrrell, Ottawa, Ont. 
Persifor Frazer, Philadelphia, Pa. Edward O. Ulrich, Newport, A i 
Warren Upham, Somerville,Mass. 
Israel C. White, Morgantown, W. J 'a. 
Newton H. Winchell, Minneapolis, Mum. 
VOLUME XIII. 
January to June. 1894. 
Minneapolis, Minn. 
The Geological Publishing Company 
1894. 
Alfred Ri ipb r, Pi inter. 
