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CONTENTS. 



Page. 

 Organization of the Geological Society of America; Proceedings of the Senii- 

 Annual Meeting held at Toronto August 28-29, 1889; Papers read at the 



Toronto Meeting; hy J. J. Stevenson, Secretary 1 



Organization of the Geological Society of America 1 



Historical Sketch of the Organization 1 



Provisional Constitution and By-Laws ' 7 



Proceedings of Meeting for Final Organization held at Ithaca, New 



York, December 27, 1888 9 



Proceedings of the Semi-Annual Meeting held at Toronto, Canada, August 



28 and 29, 1889 15 



Opening Address by the President (James Hall) 15 



Some Suggestions regarding the subdivision and grouping of the 

 Species usually included under the generic Term Orthis, in accord- 

 ance with external and internal Characters and microscopic Shell 



Structure (abstract) ; by James Hall 19 



On new Genera and Species of the Family Dictijospowjvlai (abstract) ; 



by James Hall 22 



The Strength of the Earth's Crust (abstract) ; by G. K. Gilbert .... 23 

 Bowlder Belts distinguished from Bowlder Trains— their Origin and 



Significance (abstract) ; by T. C. Chambeklin 27 



On the Trap Dikes near Kennebunkport, Maine (abstract) ; by J. F. 



Kemp 31 



The Sylvania Sand in Cuyahoga County, Ohio ; by Peter Neff... 32 

 Areas of Continental Progress in North America, and the Influence of the 

 Conditions of these Areas on the Work carried forward within them; by 

 James D. Dana 3U 



Study of a Line of Displacement in the Grand Canon of the Colorado, in 

 Northern Arizona (with figures 1-12); by Charles D. Walcott 49 



The High Continental Elevation preceding the Pleistocene (with figure 1) ; 

 by J. W. Spencer 65 



Ancient Shores, Bowlder Pavements, and High-Level Gravel Deposits in 

 the liegion of the Great Lakes (with plate 1 and figures 1-7) ; by J. W. 



Spencer 



Ori-in of the Pvock Pressure of Natural Gas in the Trenton Limestone of Ohio 



and Indiana; by Edward Orton 



Notes on the Surface Geology of Alaska (with plato 2) ; by I. C. RUSSELL.. 

 W Note on the Pre-Paleozoie Surface of the Archean Terranes of Canada; by 

 J" 2 Andrew C. Lawson "~7~7" 



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