AMERICAN JOURNAL 
SCIENCE AND ARTS. 
EDITORS AND PROPRIETORS, 
Prorrssors JAMES D. DANA anp B. SILLIMAN. 
ASSOCIATE EDITORS, 
Proressors ASA GRAY anp WOLCOTT GIBBS, 
OF CAMBRIDGE, 
AND 
Prorrssors H. A. NEWTON, S. W. JOHNSON ¥ 
GEO. J. BRUSH anv A. E. VERRILL, 
OF NEW HAVEN. 
THIRD SERIES, 
VOL. IV.—[WHOLE NUMBER, CIV.| 
Nos. 19—24. 
JULY TO DECEMBER, 1872. 
WITH FIVE PLATES. 
NEW HAVEN: EDITORS. 
1872. 
Anne 
PRINTED BY TUTTLE, MOREHOUSE & TAYLOR, 221 sTaTE srr, 
MissouR} BOTANICAL 
GARDEN LIBRARY 
