VOL. IV JULY, 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, 



of Cambridge, 



Professors HORACE L. WELLS, CHARLES SCHUCHERT, 



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. IV— [WHOLE NUMBER, CCIVj 



No. 19 -JULY, 1922. 



WITH PLATE ONE 



NEW HAVEN, CONNECTICUT. 



19 22. 



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