<-yrus Adler, 



Librarian U. S. Nat. Museum. 



VOL. XV. JUNE, 1903. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEO. L. GOODALE, JOHN TROWBRIDGE, 

 W. G. FARLOW and WM. M. DAVIS, of Cambridge, 



Professors A. E. VERRILL, HENRY S. WILLIAMS and 

 • L. V. PIRSSON, of New Haven, 



Professor GEORGE F. BARKER, of Philadelphia, 



Professor JOSEPH S. AMES, of Baltimore, 



Mr. J. S. DILLER, of Washington. 



FOURTH SERIES. 

 YOL. XY— [WHOLE NUMBER, CLXY.] 



No. 90.— MAY, 1903. 



NEW HAVEN, CONNECTIC 



1903 



THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 125 



Published monthly. Six dollars per year, in advance. $6.40 to countries in the 

 Postal Union. Remittances should be made either by money orders, registered 

 letters, or bank checks (preferably on New York banks). 



