Among articles to appear in early 
numbers of the Journal of Geology 
are the following: 
Diastrophism and the Formative Processes. XIV. Megadiastro- 
phism. By T. C. CHAMBERLIN and R. T. CHAMBERLIN. 
_ The Physical Chemistry of the Crystallization and Magmatic Differ- 
entiation of Igneous Rocks. By J. H. L. Vocr. 
The. Mineralography of the Feldspars. Bye, aA Line: 
Volcanic Earthquakes. By Cartes Davison. 
The Stratigraphic.and Faunal Relationships of the Meganos Group, 
Middle Eocene of California. By Bruce L. CLARK. 
Types of Rocky Mountain Structure in Southeastern Idaho. By 
GEORGE RoGERS MANSFIELD. 
Summaries of Pre-Cambrian Literature of North America. Papers 
VI and VII. By Epwarp STEIDTMANN. 
Russell Fork Fault: of Southwest Virginia. By CHESTER K. 
_ WENTWORTH. 
Cycles of Erosion in the Piedmont Province of Pennsylvania. By 
F. Bascom. 
Through the generosity of an associate editor of the Journal, 
Dr. R. A. J. Penrose, Jr., the announced reduction to six issues 
will- not be necessary for Volume XXIX.— Subscribers will 
receive eight issues without change in price. (See Editorial 
Note in this number.) 
