library, U. S. Nat. Museum. 



70L. L SEPTEMBER, 1920 



Established by BENJAMIN SILLIMAN in 1818. 



-cy* 5 *™ 



THE / SEP" 



AMERICA 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOODALE, JOHN" TROWBRIDGE, 

 and WM. M. DAVIS, of Cambridge, 



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



SCHUCHERT, 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. L— [WHOLE NUMBER. CC]. 



No. 297— SEPTEMBER, 1920. 



NEW HAVEN, CONNECTICUT. 



19 20. 



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