Dr. Cyrus Adler, 



Librarian U. S. Nat. Museum. 



VOL. XXV. 



APRIL, 1908. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF • SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOOD ALE, JOHN TROWBRIDGE, 

 W. G. FARLOW and WI. M. DAVIS, of 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 

 VOL. XXV— [WHOLE NUMBER, CLXXV.] 

 No. 148— APRIL, 1908. 



NEW HAVEN, CONNECTICUT. 



1908 



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



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