n CONTENTS OF VOLUME /. 



NUMBER VII. 



Geologic Time, as Indicated by the Sedimentary Rocks of North 



America. Charles D. Walcott. 639 



On the Origin of the Pennsylvania Anthracite. John J. Stevenson. 677 



The Basic Massive Rocks of the Lake Superior Region. W. S. 



Bayley 688 



On the Geological Structure of the Mount Washington Mass 



OF THE Taconic Range — PlatesIII, IV. Wm. H. Hobbs. . 717 



Editorials. 737 



Reviews: Correlation Papers, The "Newark" System; Israel Cook Russell, 

 by Wm. M. Davis. Text-Book of Comparative Geology ; E. Kayser, 

 Ph.D., by Rollin D. Salisbury. Iowa Geological Survey, vol. I. First 

 Annual Report; Samuel Calvin, State Geologist, by C. H. Gordon. . 740-747 



NUMBER VIII. 



The Supposed Glaciation of Brazil. John C. Branner. . .• . 753 



Causes of Magmatic Differentiation. Helge Backstrom. . . 773 



The Geologial Structure of the Housatonic Valley Lying East 



OF Mount Washington; Plates V, VI, VIL Wm. H. Hobbs. . 780 



The Newtonville Sand-Plain. F. P. Gulliver 803 



The Structures, OraciN, and Nomenclature of the Acid volcanic 



Rocks of South Mountain. F. Bascom 813 



Studies for Students : Genetic Relationships Among 'Igneous Rocks ; 



Joseph P. Iddings. .......... 833 



Editorials , . . 845 



Reviews : Recent Contributions to the Subject of Dynamometamorphism ; 



A. Heim. C. Schmidt, L. Milch, M. P. Termier, by George H. 



Williams. Text-Book of Geology ; Sir Archibald Geikie, by Rollin 



D. Salisbury. Bodengestaltende Wirkungen der Eiszeit; Dr. Aug. 



. Bohm, by Wm. M. Davis 850-859 



Analytical Abstracts of Current Literature : Conditions of Appa- 

 lachian Faulting ; Bailey Willis and C. W. Hayes. Ueber Geroll- 

 Thonschiefer glacialen Ursprungs in Kulm des Frankenwaldes; Ernest 

 Kalkowski. 861-862 



Acknowledgments. , . . . 863 



