Volume XVIII 



Number 6 



THE 



Journal of Geology 



A Semi -Quarterly flagazine of Geology and 

 Related Sciences 



SEPTEMBER-OCTOBER, igio 



EDITORS 



T. C. CHAMBERLIN, in General Charge 



R. D. SALISBURY R, A. F. PENROSE 



Geographic Geology Economic Geology 



J. P. IDDINGS C. R. VAN HISE 



Petrology Structural Geology 



STUART WELLER W. H. HOLMES 



Paleontologic Geology Anthropic Geology 



S. W. WILLISTON, Vertebrate Paleontology 



ASSOCIATE EDITORS 



SIR ARCHIBALD GEIKIE 



Great Britain 

 H. ROSENBUSCH 



Germany 

 CHARLES BARROIS 



France 

 ALBRECHT PENCK 



Germany 

 HANS REUSCH 



Norway 



GERARD DE GEER 



Sweden 



T. W, E. DAVID 



Australia 



O. A. DERBY 



Brazil 

 G. K. GILBERT 



Washington, D. C, 

 H. S. WILLIAMS 



Cornell University 

 C. D. WALCOTT 



Smithsonian Institution 

 J. C. BRANNER 



Stanford University 

 W. B. CLARK 



Johns Hopkins University 

 WILLIAM H. HOBBS 



University of Michigan 



TH. TSCHERNYSCHEW, Russia 



CHICAGO AND NEW YORK 

 William Wesley & Son, London 



