BUIJJOTIN OF TJIE GEOLOGICAL SOCIETY OF AMERICA 



Trigoiiiini^ of the Pacific coast of North America [abstract] ; 



by E. L. Packard 148 



Peccary from Rancho i:^a Brea [abstract] ; by John C. Mer- 



RiAM and Chester Stock 149 



Election of officers 149 



Constitution and By-Laws of the Paleontological Society 150 



Proceedings of the First Annual Meeting of the Society of Economic Geol- 

 ogists, held at Chicago, Illinois, December 28-29, 1920 ; J. Volney Lewis, 



Secretary IS"*" 



Session of Tuesday, December 28, 1920 157 



List of officers for 1920 157 



Election of officers for 1921 157 



Presentation of papers 158 



Session of Wednesday, December 29, 1920 158 



Presentation of papers 158 



Constitution and By-Laws 159 



Proceedings of the First Annual Meeting of the Mineralogical Society of 

 America, held at Chicago, Illinois, December 29, 1920 ; Herbert P. Whit- 

 lock, Secretary • • 163 



Session of Wednesday, December 29, 1920 163 



List of officers for 1920 163 



Election of officers for 1921 : 164 



Presentation of papers 164 



Constitution and By-Laws 167 



Important epochs in the history of petroleum and natural gas ; Presiden- 

 tial address by I. C. White 171 



Groundwork of the earth's diastrophism ; by T. C. Chamberlin 197 



The greater earth ; by T. C. Chamberlin 211 



Geology and geography in the United States; by E. B. Mathews and 



H. P. Little 227 



Igneous geology of southeastern Idaho ; by G. R. Mansfield 249 



Pre-Cambrian rocks of Manitoba ; by F. J. Alcock and E. L. Bruce 267 



Windrow formation : An upland gravel formation of the driftless and ad- 

 jacent areas of the upper Mississippi Valley;. by E. T. Thwaites and 



W. H. Twenhofel 293 



Observations on the mode of life of primitive cephalopods ; by R. Ruede- 



MANN 315 



Status of our knowledge of Mesozoic pathology ; by R. L. Moodie 321 



Evolution, phjdogeny, and classification of the Mastodontoidea ; by H. F. 

 OSBORN 327 



Criteria for the determination of the climatic environment of extinct ani- 

 mals ; by E. C. Case 333 



Methods of determining the relationships of marine invertebrate fossil 

 faunas ; by C. Schuchert 339 



Criteria for species, phytogenies, and faunas of trilobites ; by P. E. Ray- 

 mond 349 



Criteria for determination of climate by means of fossil plants ; by F. H. 

 Knowlton 353 



