AMERICAN JOURNAL 
SCIENCE AND ARTS. 
CONDUCTED BY 
PROFESSORS B. SILLIMAN, B. SILLIMAN, Jp, 
AND 
JAMES D. DANA, 
IN CONNECTION WITH 
PROF. ASA GRAY, or CAMBRIDGE, | 
PROF. . LOUIS AGASSIZ, or CAMBRIDGE, 
DR. WOLCOTT GIBBS, or NEW YORK. 
SECOND SERIES. 
VOL. XX ViIl--~MAY, 1845: 
WITH A PLATE. 
NEW HAVEN: EDITORS. 
1859. 
E. HAYES, PRINTER. 
NICAL 
‘ ; URI BoTA 
i wiesO an LIBRARY 
GARD 
