IV BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Page 

 Evidence that the fossiliferous gravel and sand beds of Iowa and Nebraska are 



Aftonian ; by B. Shimek 119 



Some mineral relations from the laboratory viewpoint ; by Arthur L. Day. . . 141 

 Bearing of the tertiary mountain belt on the origin of the earth's plan; by 



Frank Bursley Taylor 179 



Isobases of the Algonquin and Iroquois beaches, and their significance ; by 



James Walter Goldthwait 227 



Cacops, Desmo&pondylus ; new genera of Permian vertebrates ; by S. W. Wil- 



liston 249 



Migration and shifting of Devonian faunas ; by Henry S. Williams 285 



Persistence of fluctuating variations as illustrated by the fossil genus rhipido- 



mella ; by Henry S. Williams 295 



North American natural bridges, with a discussion of their origin ; by Herd- 

 man F. Cleland 313 



Alaskan earthquakes of 1899 ; by Lawrence Martin 339 



Birds Hill, an esker near Winnipeg, Manitoba ; by W arren Upham 407 



Relationship of Niagara River to the Glacial period ; by J. W. Spencer 433 



Relative work of the two falls of Niagara ; by J. W. Spencer 441 



Interruption in the flow of the falls of Niagara in February, 1909 ; by J. W. 



Spencer 447 



Geologic work of ants in tropical America ; by J. C. Branner 449 



Internal characters of some Mississippian rhynchonelliform shells; by Stuart 



Weller 497 



New light on the geology of the Wasatch Mountains, Utah; by Eliot Black- 



AVELDUR 517 



Relations of present profiles and geologic structures in desert ranges; by 



Charles R. Keyes 54:^ 



Deflation and the relative efficiences of erosional processes under conditions of 



aridity ; by Charles R. Keyes 565 



Beach cusps ; by Douglas W^ilson Johnson 599 



Criteria for the recognition of the various types of sand grains ; by William 



H. Sherzer 625 



Rock streams of Veta Peak, Colorado ; by Horace B. Patton 663 



Ordovicic-Siluric section of the Mingan and Anticosti islands, Gulf of Saint 



Lawrence; by Charles Schuchert and W. H. Twenhofel 677 



Some eff"ects of glacial action in Iceland ; by Fred Eugene Wright 717 



Tables for the determination of crystal classes ; by W. S. Tangier Smith. . . 731 



Additional note on the geometry of faults ; by Harry Fielding Reid 737 



Supplementary note on the organization of the Geological Society of America ; 



by C. H. Hitchcock 741 



Richmond and Great Barrington bowlder trains ; by F. B. Tayi^or 747 



Abstracts of papers presented at the Twenty-second Annual Meeting of the 

 Society, but not published in full in the preceding pages of this volume, to- 

 gether with discussions of papers as far as preserved ; E. O. Hovey, Secretary. 753 

 Post-Tertiary history of the lakes of Asia Minor and Syria [abstract and 



discussion] ; by Eli<sworth Huntington 755 



Tide-water glaciers of Prince William Sound and Kenai Peninsula, Alaska 



[abstract] ; by U. S. Grant 757 



Oscillation of Alaskan glaciers [abstract and discussion] ; by R. S. Tarr 

 and L A WRENCE Martin 758 



