Library, U. S. Nat. Museum. 

 VOL. II 



DECEMBEE, 1921 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWAKD S. DAITA. 



associate editors 



Professors WILLIAM M. DAVIS and REGINALD A. DALY, 



OF Cambridge, 



Professors HORACE L. WELLS, CHARLES SCHUCHBRT, 



HERBERT E. GREGORY, WESLEY R. COE and^ 



FREDERICK E. BEACH, of New Haven, 



Professor EDWARD W. BERRY, of Baltimore, 

 Drs. FREDERICK L. RANSOME and WIL^^f' BOWIE, 



OF Washington. / ""^ 



> m s - m 



FIFTH SERIES 



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VOL. II— [WHOLE NUMBEK, GCII]. 

 No. 12— DECEMBER, 1921. 



WITH PLATE I. 



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