Vol. VII No. 4 



February 19, 1917 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 



N. Ernest Dorset Adolph Knopf A. S. Hitchcock 



^bureau of standards geological subvey bitreaoJofjflantJindustby 



\ 



PUBLISHED SEMI-MONTHLY 

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WASHINGTON ACADEMY OF SCIENCES 



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 WILLIAMS & WILKIN8 COMPANY 

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