Bulletin No. 22 1922 Entomological Series, No. 2 



BULLETIN 



LLOYD LIBRARY 



of 



BOTANY, NATURAL HISTORY 

 PHARMACY AND 

 MATERIA MEDICA 



FOUNDED, ENDOWED AND MAINTAINED 



BY 



CURTIS G. LLOYD 



ENTOMOLOGICAL SERIES, No. 2 



NOTES ON THE BIOLOGY OF SOME OF OUR 

 NORTH AMERICAN SPECIES OF MAY-FLIES/ 



Helen E. Murphy 



I. The Metamorphosis of May-fly Mouth Parts. 

 II. Notes on the Biology of May-flies of the Genus Baetis. 



"Contribution from the Limnological Laboratory, Cornell University. 



