V 



N H 



THE 



JOURNAL OF GEOLOGY 



A Semi-Quarterly Magazine of Geology and 

 Related Sciences 



Editors 



T. C. CHAMBERLIN, in General Charge 



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



Geographic Geology Economic Geology 



J. P. IDDINGS C. R. VAN HISE 



Petrology Pre-Cambrian 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 



Austria, 

 HANS REUSCH 



Norway 

 GERARD DE GEER 



Sweden 



O. A. DERBY 



Brazil 



G. K. GILBERT 



Washington, D. C. 



H. S. WILLIAMS 



Yale University 



C. D. WALCOTT 



U. S. Geological Sjirvey 



J. C. BRANNER 



Stanford University 



I. C. RUSSELL 



University of Michigan 



W. B. CLARK 



Johns Hopkins University 



VOLUME XI 



CHICAGO 



Ei)e muibersits of OTfticago Press 



1903 



