ALBERT JOHANN S 
> 
STI, Economic Geoloey ! » ROLLIN T. CHAMBERLIN, Dyna Geology 
ASSOCIATE EDITORS 
D ore, aS Britain : i JOHN C. BRANNER, Leland Stanford Junior University 
; - RICHARD A. F. PENROSE, Jr., Philadelphia, Pa. 
~ WILLIAM H. HOBBS, University of Michigan 
FRANK D. ADAMS; McGill University 
; : CHARLES K. LEITH, University 01 Wisconsin 
(ORTH DAVID, Australia. ~ WALLACE W. ATWOOD, Clark Univers ty — 
S, Leland Stanford Junior University WILLIAM H. EMMONS, University of Mianmesota) 
ALI ane; Smithsonian Institution ARTHUR L. DAY, Carnegie Institution x 
APRIL-MAY 1921 
Haroitp L. ALLING 
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