V 



NM 



THE 



JOURNAL OF GEOLOGY 



A Semi-Ouarterly Magazine of Geology and 

 Related Sciences. 



Editors 



T. C. CHAMBERLIN 



R. D. SALISBURY, C. R. VAN HISE, 



Geographic Geology. Pre- Cambrian Geology. 



J. P. IDDINGS, C. D. WALCOTT, 



Petrology. Paleofitologic Geology. 



R. A. F. PENROSE, Jr. W. H. HOLMES, 



Economic Geology. Archeologic Geology. 



GEORGE BAUR, 



Vertebrate Paleo7itology. 



Associate Editors 



SIR ARCHIBALD GEIKIE, 



Great Britain. 

 H. ROSENBUSCH, 



GerDiany. 



CHARLES BARROIS, 



Fratice. 

 ALBRECHT PENCK, 



Austria. 

 HANS REUSCH, 



iVorway. 

 GERARD DE GEER, 



Swede ti. 

 GEORGE M. DAWSON, 



Canada. 



JOSEPH LE CONTE, 



University of California . 

 G. K. GILBERT, 



Washifigton. 

 H. S. WILLIAMS, 



Yale University. 

 J. C. BRANNER, 



Leland Stanford, Jr. University. 

 G. H. WILLIAMS, 



Johns Hopkins University. 

 I. C. RUSSELL, 



Unive?-sity of Michigan. 

 O. A. DERBY, 



Brazil. 



VOLUME I 



1893 



CHICAGO 





