Dr. Cyrus Adler, 



Librarian U. S. Nat. Museum. 



c. n VOL. XXIII. 



FEBRUARY, 1907. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWABD S. DANA. 



ASSOCIATE EDITORS 



Professors GEOKGE L. GOODALE, JOHN TEOWBEIDGE, 

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



Professors ADDISON E. VEEEILL, HOEACE L. WELLS, 

 L. V. PIESSON and H. E. GEEGOEY, of New. Haven, 



Professor GEOEGE F. BAEKEE, of Philadelphia, 

 Professor HENEY S. WILLIAMS, of Ithaca, 

 Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J. S. DILLEE, of Washington. 



FOURTH SERIES 

 VOL. XXIII— [WHOLE NUMBER, CLXXIIL] 



No. 134— FEBRUARY, 1907. 



WITH PLATE I. 



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 1907 



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