EARTH 



SCIENCES 



LIBRARY 



PUBLICATION COMMITTEE: 



HENRY SKINNER, M.D., Sc.D., WITHER STONE, A.M., Sc.D., 

 HENRY A. PILSBRY, Sc.D., WILLIAM J. Fox, 



EDWARD J. NOLAN, M.D. 

 The President, SAMUEL GIBSON DIXON, M.D., LL.D., ex-officio. 



EDITOR : HENRY A. PILSBRY. 

 TREASURER : S. RAYMOND ROBERTS. 



