Dr. Cyrus Adler, 



Librarian U. S. Nat. Museum. 



YOL. XXIY. AUGUST, 1907. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. JOODALE, JOHN TROWBRIDGE, 

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



Professors ADDISON E. VERRILL, HORACE L. WELLS, 

 L. V. PIRSSON and H. E. GREGORY, of New Haven, 



Professor GEORGE F. BARKER, of Philadelphia, 

 Professor HENRY S. WILLIAMS, of Ithaca, 

 Professor JOSEPH S, AMES, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES 



YOL. XXIY— [WHOLE NUMBEE, CLXXIY.] 



No. 140— AUGUST, 1907. 



NEW HAYEN, CONNECTICUT. 



1907 



THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 



Published monthly. Six dollars per year, in advance. $0*4€r^9\qoUi^fies in the 

 Postal Union ; $6.25 to Canada. Remittances should be maet^SGfier by nioneyToVde^s, 

 registered letters, or bank checks (preferably on New York / aj&hks). .« j 



