CONTENTS XI 



Page 



Sauropoda aud Stegosauria of the Morrison of North America compared 



with those of Eliirope and eastern Africa ; by Richard Swann Lull. . . . 323 

 I'aleobotanic evidence of the age of the Morrison formation ; l)y Edward 



WiLBER Berry 335 



Invertebrate fauna of the Morrison formation; by T. W. Stanton 343 



Studies of the morpliology and liistology of the Trepostomata or Monti- 



culiporoids ; by E. R. Cumixgs and J. J. Galloway 349 



Present condition of the volcanoes of southern Italy ; by H. S. Washing- 



Tox and Arthur L. Day" 375 



Proceedings of the Summer Meeting of the Geological Society of America, 

 held at the University of California and at Stanford University, August 



3, 4, and 5, 1915 ; J. A. Taff, Secretary pro tern 389 



Session of Tuesday, August 3 390 



Titles and abstracts of papers presented and discussions thereon . 391 

 Epigene profiles of the desert [abstract and discussion] ; by 



Andrew C. Lawsox 391 



Bajadas of the Santa Cataliua Mountains, Arizona [abstract 



and discussion] ; by C. F. Tolman, Jr 391 



Origin of the tufas of Lake Lahontan [abstract] ; by J. C. 



Jones 392 



Some physiographic features of bolsons [discussion] ; by 



Herbert E. Gregory 392 



Sculpturing of rock by wind in the Colorado plateau prov- 

 ince ; by Herbert E. Gregory 393 



Session of Wednesday. August 4 393 



Titles aud abstracts of papers presented and discussions thereon . 393 

 Some chemical factors affecting secondary sulphide ore en- 

 richment [abstract and discussion] ; by S. W. Young 393 



Role of colloidal niigratiou in ore deposits [abstract and dis- 

 cussion] ; by John D. Clark 394 



Examples of progressive change in the mineral composition 

 of coppei- ores [abstract ;ind discussion] ; by C. F. Tolman, 



Jr 394 



Sericite, a low tempei-ature hydrothermal mineral [ab.stract] : 



by A. F. Rogers 395 



Dinner 395 



Session of Thursday. August 5 395 



Titles and abstracts of papers presented and discussions thereon. 395 

 Physiographic control in the Philippines [abstract and dis- 

 cussion] ; by Warren D. Smith 395 



Origin of the Iiasins within the hamada of the Libyan Desert 



[abstract] : by William H. Hobbs 396 



Tiimited effective vertical range of the desert sand-blast, 

 based on ob.serviitions made in the Libyan Desert and in the 

 .\nglo-Egypfi;in Sudan [abstract]; )>y William H. IIorbs.. 396 

 Characteristics of the Lassen Peak eruptions of May 20-22. 

 1915 [abstract iind discussion] ; by Ruliff S. Holway and 

 J. S. Dtt T,r R .397 



