Jo. 166, Vou. XXVUL | OCTOBER. 1884, 
: : 
} 
Established by BENJAMIN SILLIMAN in 1818. 
THE 
AMERICAN : 
JOURNAL OF SCIENCE. 
EDITORS 
JAMES D. ann EB. S. DANA, ayp B. SILLIMAN, . 
ASSOCIATE EDITORS a oS 
Proressors ASA GRAY, JOSIAH P. COOKE, Fr 
JOHN TROWBRIDGE, OF Campringe, 
Proressors H. A. NEWTON ann A.B Na 
New Haven, 
Prorressorn GEORGE F. BARKER, oF Punape.ea 
“THIRD SERIES, Se 
Be oh 2 166--OCTOBER, 188, 
