CONTENTS OF VOLUME VI v 



PAGE 



Probable Stratigraphical Equivalents of the Coal Measures of 



Arkansas. Charles R. Keyes -------- 356 



On the Origin of Certain Siliceous Rocks 



I. Notes on Arkansas Novaculite. Orville A. Derby - - - 366 



II. On the Origin of Novaculites and Related Rocks. J. C. Branner 368 



A Study of Some Examples of Rock Variation. J. Morgan Clements - 372 



Studies for Students : The Development and Geological Relations of 



the Vertebrates (Part I — The Fishes) E. C. Case - - - - 393 



Editorial- ....-.-- 417 



Reviews : Van Hise's Principles of Pre-Cambrian Geology (review by 

 Bailey Willis), 419 ; Topographic Atlas of the United States — "Physi- 

 ographic Types," by Henry Gannett (review by W. M. Davis), 431 ; 

 Volcanoes of North America, by Israel C. Russell (review by J. P. I.), 

 434 ; Revised Text-Book of Geology, by James D. Dana, edited by 

 William North Rice (review by T. C. C), 435 ; Fossil Plants for Stu- 

 dents of Botany and Geology, Vol. I, by A. C. Seward (review by 

 Henry C. Cowles), 436 ; Northward Over the " Great Ice," by Robert 

 E.Peary (review by T. C. C), 438 ; United States Geologic Atlas, 

 Folio 41, Sonora, California, by H.W.Turner and F. L. Ransome, 441 419-443 



Recent Publications ---------- 444 



NUMBER V. 



The Ulterior Basis of Time-Divisions and the Classification of 



Geologic History. T. C. Chamberlin ------ 449 



The Postglacial Connecticut at Turners Falls, Mass. M. S. W. 



Jefferson ------------ 463 



The Variations of Glaciers. III. Harry Fielding Reid - - - 473 



Notes on the Kalamazoo and Other Old Glacial Outlets in South- 

 ern Michigan. C. H. Gordon ------- 477 



Notes on Some Igneous, Metamorphic, and Sedimentary Rocks of 



the Coast Ranges of California. H. W. Turner - - - 483 



Studies for Students : The Development and Geological Relations of the 



Vertebrates (Part II— Amphibia ; Part III— Reptilia). E. C. Case 500 



Editorial - - ----- 5 2 4 



Summaries of Current North American Pre-Cambrian Literature. 



C. K. Leith - - 5 2 7 



Reviews : United States Geologic Atlas, Folio 42, Bidwell Bar, California, 

 by H. W. Turner, 542; North Carolina Geological Survey, Bull. 13; 



