SMITHSONIAN 



CONTRIBUTIONS TO KNOWLEDGE 



VOL. XXXV 



EVERY MiN IS A VALUABLE MEMBElt OF SOCIETV WHO, BV HIS OBSERVATIONS, RESEARCHES, AVU EXPERIMENTS, PROCURES 



KNOWLEDGE FOR MEN— SMITH80N 



(No. 1740) 



AUG 16 1917^^^: 



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t!^onal Mus«^t^ 



CITY OP WASHINGTON 

 PUBLISHED BY THE SMITHSONIAN INSTITUTION 



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