The Journal of Geology 



Edited By 



thomas c. chamberl1n and rollin d. salisbury • 



With the Active Collaboration of 



SAMUEL W. WILLISTON ALBERT JOHANNSEN 



Vertebrate Paleontology Petrology 



STUART WELLER ROLLIN T. CHAMBERLIN 



Invertebrate Paleontology Dynamic Geology 



ALBERT D. BROKAW 



Economic Geology 



The Journal of Geology is published by the University of Chicago at the University Press semi- 

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Entered as second-class matter, March 20, 1893, at the Post-office at Chicago, 111., under the Act of March 3, 1879. 



