Library, U. S. Nat. Museum. 



VOL. Ill 



JUNE, 1922 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors WILLIAM M. DAVIS and REGINALD A. DALY, 



op Cambridge, 



Professors HORACE L. WELLS, CHARLES SCHUCEERT, | 

 HERBERT E. GREGORY, WESLEY R. COE and 

 FREDERICK E. BEACH, of New Haven, 



Professor EDWARD W. BERRY, of Baltimore, 

 Drs. FREDERICK L. RANSOME and WILLIAM BOWIE, 



of Washington. 



FIFTH SERIES 



VOL. Ill— [WHOLE NUMBER, CCIII]. 



No. 18— JUNE, 1922. 



NEW HAVEN, CONNECTICUT. 



19 22. 



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