Bulletin No. 270 Series B, Descriptive Geology, 73 
DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY; 
CHARLES D. WALCOTT, DlRECTOB 
THE 
CONFIGURATION OF THE 
ROCK FLOOR OF 
GREATER NEW YORK 
BY 
WILLIAM HERBERT HOBBS 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1905 
