ro tion oS Kee Se nt 
Established by BENJAMIN SILLIMA. ‘or, and T. Orata, 
ess. $5 per - 
No. 171 Vou 3X1x. 
BOL 
AMERICAN 
JOURNAL OF SCIENCE 
JAMES D. axp EDWARD S. DANA. 
ASSOCIATE EDITORS 
PROFESSORS ASA GRAY, J OSIAH P. COOKE, AND 
JOHN TROWBRIDGE, or CamBripgs, — 
Proressors H. A. NEWTON anp A. E. VERRILL, ° 
arte New Haves, fess 
