t 



BULLETIN 



OF 



The American Museum of Natural History 



Volume XLII, 1920 



59.57, 63H 



Article I.— STUDIES ON THE BIOLOGY OF THE AQUATIC 



HYDROPHILIDiE/ 



By E. Avery Richmond 



M » 



Plates I to XVI 



CONTENTS 



Page 



i. introduction 3 



Historical 3 



[Methods of Collecting 8 



Methods of Rearing 9 



II. Life History and Biology 10 



General Survey 10 



Explanation of Terms LJsed 12 



General Characters of the Family (Immature Stages) 14 



General Characters, Life History, and Biology of the Forms Studied 17 



1. Helophorin* 17 



Helophorus (PI. II) 17 



H. lacustris 18 



H. aquaticus 20 



2. Limnebiinae 20 



Limnebius 21 



L. discolor 21 



3. Hydrgeninse 21 



Ochthebius (PI. IIIj 21 



O. tuberculatum 22 



Hydrana (PL IV) 24 



H. pennsylvanica 24 



4. Hydroscaphinee 27 



5. Hydrochoinse 27 



Hydrochous (PL V) 27 



H. squamifer 29 



i 



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