Order EPHEMERIDA. 



The members of this order are popularly known as "May flies" because 

 of the time of their greatest abundance, or "day flies" because of their 

 short life in the adult stage. The ordinal term here used is based upon 

 this same peculiarity in their life cycle. The adults have two pairs of 

 wings, very closely net-A'eined, frail in texture, and the anterior much 

 larger than the posterior. The head is large, set on a distinct neck, the 

 mouth parts are aborted, the eyes prominent and the antennas very short. 

 The body is loosely jointed and the abdomen has long anal filaments, 

 varying from three to five in number. The insects are attracted to light 

 and on favorable evenings in early summer often come in swarms to the 

 electric lights in cities or towns on lake or river banks. The early stages 

 are passed in the water, the larvse feeding in the mud and ooze, some- 

 times for a considerable number of years, before they attain maturity. 



There are many interesting and peculiar 

 structures in this, perhaps the most ancient of 

 the existing types of insects, and the enormous 

 numbers of individuals that still occur, even 

 though the number of species is limited, indi- 

 cates the richness in organic life of the bottoms 

 in which they feed. They are not of economic 

 importance from any point of view. 



POLYMITARCYS Eaton. 

 P. albus Say. New Brunswick in July. 



HEXAGENIA Walsh. 



H. bilineata Say. Caldwell (Cr); New Bruns- 

 wick (Coll); Westville VI, Riverton VII, 

 (Jn). 



H. limbata Pict. Echo Lake, Passaic Co. VII, 

 2, Normannock VII (Ds). 



Fig. 4. An adult May-fly. 



EPHEMERA Linn. 

 E. decora Wlk. Caldwell, common (Cr). 



LEPTOPHLEBIA Westw. 



L. cupida Say. (Blasturus) Great Piece Meadows IV, 10-28, very com- 

 mon (Gr); Caldwell (Cr) ; Ft. Lee V, 1, Staten Island IV, 17, 27 

 (Ds); Jamesburg, Trenton IV, 30, Lahaway IV, 1 (Coll); Westville 

 IV, 9 (Jn). 



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