October-November 1923 Vol. XXXI, No. 7 



The Journal of Geology 



Edited By 

 thomas c. chamberlin 



With the Active Collaboration of 



ROLLIN T. CHAMBERLI^. Managing Editor 

 Dynamic Geology 

 STUART WELLER ALBERT JOHANNSEN 



Invertebrate Paleontology Petrology 



EDSGN S. BASTIN j HARLEN BRETZ 



Economic Geology Stiatigraphic Geoloi?y 



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