if og. . 2 , 
UNITED STATES 
EXPLORING EXPEDITION. 
DURING THE YEARS 
1838 , 1839 , 1840 , 1841 , 1842 . 
UNDER THE COMMAND OF 
CHARLES WILKES, U. S. N. 
ATLAS. 
E O L O G 
BY 
JAMES D. DANA, A. M., 
GEOLOGIST OF THE EXPEDITION. 
MEMBER OF THE SOC. CHSS. NAT. CUR. OF MOSCOW, THE SOC. PHILOMATHIQUE OF PARIS, 
THE AMERICAN ACADEMY OF ARTS AND SCIENCES AT BOSTON, ETC. 
NEW YORK: 
GEO. P. PUTNAM, 155 BROADWAY. 
LONDON: PUTNAM’S AMERICAN AGENCY, 
49 BOW LANE, CHEAPSIDE. 
/ ? 7 
*z> 
