OLUME XXXI 



THE 



NUMBER 4 



Journal of Geology 



A Semi-Quarterly 



Edited By 



THOMAS C. CHAMBERLi: 



With the Active Collaboration of 



ROLLIN T. CHAMBERLIN, Managing Editor 

 Dynamic Geology 

 STUART WELLER, Invertebrate Paleontology ALBERT JOHANNSEN, Petrology 



EDSON S. BASTIN, Economic Geology J. HARLEN BRETZ, Stratigraphic Geology 



ASSOCIATE EDITORS 



JJIR ARCHIBALD GEIKIE, Great Britain 

 :HARLES BARROIS, France 

 iLBRECHT PENCK, Germany 

 IANS REUSCH, Norway 

 iERARD DeGEER, Sweden 

 ,IR T. W. EDGEWORTH DAVID, Australia 

 \L ALBERT BROUWER, Holland 

 IaILEY WILLIS, Leland Stanford Junior University 



ARTHUR L. 

 * Deceased 



DAY, 



CHARLES D. WALCOTT, Smithsonian Institution 

 DAVID WHITE, U.S. Geological Survey 

 RICHARD A. F. PENROSE, Jr., Philadelphia, Pa. 

 WILLIAM H. HOBBS, University of Michigan 

 FRANK D. ADAMS, McGill University 

 CHARLES K. LEITH, University of Wisconsin 

 WALLACE W. ATWOOD, Clark University 

 WILLIAM H. EMMONS, University of Minnesota 

 Carnegie Institution 



MAY-JUNE 1923 



He differentiation of the drift sheets of northwestern ILLINOIS 



Morris M. Leighton 265 



HE MINERALOGRAPHY OF THE FELDSPARS, PART II - - Harold L. Alling 282 



PRELIMINARY REPORT ON THE MICROSCOPY OF ANTHRACITE COAL 



Homer G. Turner and H. R. Randall 306 



lEGLOGY OF THE PHILIPSBURG REGION OF QUEBEC WITH NOTES ON CORRE- 



; LATIONS WITH THE BEEKMANTOWN J. H. Bradley, Jr. 314 



OLDS RESULTING FROM VERTICALLY ACTING FORCES - - W. I. Robinson 336 



PALEOZOIC ANGIOSPERM - A. C. Noe 344 



:OMMUNICATION - - - - - - - - - 348 



-EVIEWS - - 349 



THE UNIVERSITY OF CHICAGO PRESS 



CHICAGO, ILLINOIS, U.^.A. 



THE CAMBRIDGE UNIVERSITY PRESS, London 



THE MARUZEN-KABUSHIKI-KAISHA, Tokyo, Osaka, Kyoto, Ftoitoko, Sendai 



THE MISSION BOOK COMPANY, Shanghai 



