Vol. V No. 19 



NOVEMBEB 19, 1915 



JOUENAL 



OP THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 



Fred. E, Wright William R. Maxon Edson S. Bastim 



qkophtsical labobatort national mtbxcm oboloaical scbtat 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY. AUGUST, AND SEPTEMBER, WHEN MONTHLY. 



BT TBB 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



THE WAVERLV PRESS 



BALTIMORE, MB. 



