JOSEPH HTU&ru, 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES D. WALCOTT, DIRECTOR 
THE 
OCCURRENCE AM) DISTRIBUTION 
01 
CORiXDl J)i IX TIIK rMTKD STATES 
BY 
.K>SEI>]I IIVDE PRATT 
WASHINGTON 
G O V K R N M K N T I' It I N T I N G O F F I C E 
1 9 1 
