

VOL. XLVIII AUGUST, 1919. 



Established by BENJAMIN SILLIMAN in 1818. 



AMERI 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOODALE, JOHN TROWBRIDGE, 

 and WI. M. DAVIS, of Cambridge, 



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



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



and HORACE S. UHLER, of ISTew Haven, 



Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES 



VOL. XLVIII— [WHOLE NUMBER. CXCVIIIj. 



No. 284— AUGUST, 1919. 



NEW HAVEN, CONNECTICUT. 



19 19. 



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