VOLUME XXV 



THE 



NUMBER 4 



Journal of Geology 



l i Y 



A Semi-Quarterly 



Edited By 



THOMAS C. CHAMBERLIN AND ROLLIN D. SALISBURY 

 Withv the Active Collaboration of 



SAMUEL W. WILLISTON, Vertebrate Paleontology ALBERT JOHANNSEN, Petrology 

 STUART WELLER, Invertebrate Paleontology ROLLIN T. CHAMBERLIN, Dynamic Geology 

 ! ' •' ' ALBERT D. BROKAW, Economic Geology 



Associate editors 



SIR ARCHIBALD GEIKIE, Great Britain 



CHARLES BARROIS, France 



ALBRECHT PENCK, Germany 



HANS REUSCH, Norway 



GERARD DeGEER, Sweden 



T. W. EDGEWORTH DAVID, Australia 



BAILEY WILLIS, Leland Stanford Junior University 



GROVE K. GILBERT, Washington, D.C. 



CHARLES D. WALCOTT, Smithsonian Institution 



HENRY S. WILLIAMS, Cornell University 



JOSEPH P.IDDINGS, Washington, D.C. 

 JOHN C. BRANNER, Leland Stanford Junior University 

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

 WILLIAM B. CLARK, Johns Hopkins University 

 WILLIAM H. HOBBS, University of Michigan 

 FRANK D. ADAMS, McGill University 

 CHARLES K. LEITH, University of Wisconsin 

 WALLACE W. ATWOOD, Harvard University 

 WILLIAM H. EMMONS, University of Minnesota 

 ARTHUR L. DAY, Carnegie Institution 



MAY-JUNE 1917 



LABIDOSAURUS COPE, A LOWER PERMIAN COTYLOSAUR REPTILE FROM TEXAS 7 



,' . , Samuel ,W, Williston 309 



NOTES ON THE 1916 ERUPTION OF MAUNA LOA 



Harry 0. Wood 322 



AGE AND STRATIGRAPHIC RELATIONS OF THE OLENTANGY SHALE OF CEN- 

 TRAL OHIO, WITH REMARKS ON THE PROUT LIMESTONE AND SO-CALLED 

 OLENTANGY SHALES OF NORTHERN OHIO - - Amadetjs W. Grabatj 



THE HISTORY OF DEVILS LAKE, WISCONSIN - 



Arthur C. Trowbridge 



THE MIDDLE PALEOZOIC STRATIGRAPHY OF THE CENTRAL ROCKY MOUN- 

 TAIN REGION - - - - C. W. Tomlinson 



337 

 344 



373 



REVIEWS - -------- 395 



THE UNIVERSITY OF CHICAGO 



CHICAGO, ILLINOIS, U.S.A. 



PRESS 



Agents : 



THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



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



THE MISSION BOOK COMPANY, Shanghai 



