LIFE HISTORY OF THE SCAVENGER WATER BEETLE 

 HYDROUS (HYDROPHILUS) TRIANGULARIS, AND ITS 

 ECONOMIC RELATION TO FISH BREEDING : : : 

 :::::: By Charles Branch Wilson, Ph. D. 



From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXXIX, 1923-24 

 Document No. 942 : : : : : : : : : : : : : : : : : : : : : 



PRICE, 10 CENTS 



Sold only by the Sttperintendent of Documents, Government Printing OfSce, Washington, D. C 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1923 



