THE MINERAWGRAPHY OF THE FELDSPARS 375 



Kemp, Berkey, Campbell, Colony, and Kendall, of Columbia Uni- 

 versity; Professor A. N. Winchell, of the University of Wisconsin; 

 Professor Albert Johannsen, of the University of Chicago; Professor 

 William S. Bayley, of the University of Illinois; and to Dr. Henry 

 S. Washington and Dr. Pentti Eskola, of the Carnegie Institution 

 of Washington, Dr. S. Kozu, of Tohoku University, Sendai, Japan; 

 Dr. Olaf Andersen, of the Norwegian Geological Survey; Dr. Edgar 

 T. Wherry, of Washington ; Dr. Samuel G. Gordon, of the Philadel- 

 phia Academy of Science; Mr. George L. Enghsh and Dr. A. C. 

 Hawkins, of Ward's Natural Science Establishment, Rochester; 

 and Professor Henry E. Lawrence, of the Department of Physics of 

 the University of Rochester, have also rendered valuable assistance. 



ERRATA 



Page 285, ninth line from bottom. For "z . . . . monoclinictr «=t 



icilinic . . . ." read ^'monoclinic-^triclinic " 



Bottom of page 290, for ''KAISi.Ofi+SiOa^^KAISijOg" read: 



''KAlSWe+SiO^^KAlSip^'' 

 Title of Fig. 3, page 291, for ''KAlSiaOs" read "KAIShO^^ 

 Footnotes on page 292 (facing Plate I) belong on page 305. 

 Page 298 (facing Plate II) Feldspar "I," for "Granite" read "Oranite:' 

 For footnotes on page 305 see page 292. 



