XTbe 3-011 ^nal of 6eolog^ 



Vol. XXIII CONTENTS FOR OCTOBER-NOVEMBER J9J5 No. 7 



REVISION OF PRE-CAMBRIAN CLASSIFICATION IN ONTARIO Willet G. Miller and Cyril W. Knight 585 



METAMORPHIC STUDIES. CONVERGENCE TO MINERAL TYPE IN DYNAMIC METAMORPHISM 



C. K. Leiih and W. J. Mead 600 



THE AGE OF THE CRETACEOUS FLORA OF SOUTHERN NEW YORK AND NEW ENGLAND 



. Edward W. Berry 608 



A CRITICAL STUDY OF THE FOSSIL BIRD GALLINULOIDES WYOMINGENSIS EASTMAN R. W. Shueeldt 619 



GROUND-ICE WEDGES. THE DOMINANT FORM OF GROUND-ICE ON THE NORTH COAST OF ALASKA 



E. De K. Leffingwell 635 



STRATIGRAPHY OF THE WAVERLY FORMATIONS OF CENTRAL AND SOUTHERN OHIO. PART I 



Jesse E. Hyde 655 



RECENT PUBLICATIONS , 683 



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