ur. oyrus Aaier, 



Librarian U. S. Nat. Museum. 



YOL. XX. NOVEMBER, 1905. 



Established by BENJAMIN SILLIMAN in 1818. * 

 THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWAED S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOOD ALE, 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 E[ew Haven, 



Professor GEOEGE F. BAEE33E, of Philadelphia, 

 Professor HENEY S. WILLIAMS, of Ithaca, 

 Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J. S. DILLEE, of Washington. 



FOURTH SERIES 

 YOL. XX— [WHOLE NUMBER, CLXX.] 

 Xo. 119.— NOYEMBER, 1905. 



WITH PLATES X, XI. 



NEW HAVEN, CONNECTICUT. 



1905 



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



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