Library, U. S. IN at. museum. 



VOL. XLVIII DECEMBER, 1919. 



Established by BENJAMIN SILLIMAN in 1818. 



THE uu " *■ 



AMERICA 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOOD ALE, JOHN TROWBRIDGE, 

 and WM. M. DAVIS, of Cambridge, 



Professors A. E. VERRILL, HORACE L. WELLS, CHARLES 



SCHUCHERT, L. V. PIRSSON, H. E. GREGORY, 



and HORACE S. UHLER, of New Haven, 



Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J*. S. DILLER, of Washington. 



FOURTH SERIES 

 VOL. XLVIII— [WHOLE NUMBER, CXCVIII]. 



No. 288— DECEMBER, 1919. 



NEW HAVEN, CONNECTICUT. 



1919. 



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