MAT-FLIES. 



71 



a 



Family Libellulidae. Calopteryx apicalis Burm., Agrion civile 

 Hagen, jffischna heros Fabr., Libellula trimaculata De Geer. 



ORDER VI. PLECTOPTERA* (May-flies). 



Like the dragon-flies, the Ephemerae or May-flies are in 

 their own way very peculiar insects, and cannot be placed 

 in any of the older established orders. We have therefore 

 proposed the name Plectoptera for the group, 

 in allusion to the flue, gauzy network of 

 their wings. 



The adult May-flies are characterized by 

 the very rudimentary condition of the 

 mouth-parts. In examining the under side 

 of the head there is a hollow, with only 

 slight rudiments of the mandibles, maxillae, 

 and labium. As these insects live but a few 

 hours, only long enough to provide for the 

 continuance of the species, they need to 

 take no food, hence the mouth-parts are 



FIG. 57. May-fly, natural siz<5. a, larva, twice enlarged. 



nearly aborted, and the antennas are small and bristle-like. 



* SELECTED WORKS. 



Eaton, A. E. A revisional monograph of recent Ephemeridae or May- 

 flies. Parts I. -IV. (Trans. Lhm. Soc., London, 1883-85). 



Hagen, H. A. Synopsis of the Neuroptera of North America (1861). 



Lubbock, J. Development of Chloeon dimidiatum (Trans. Linn. 

 Soc., London, xxiv.-v., 1865-66). 



Packard, A. S. (External anatomy, in third report U. S. Entomolog. 

 Commission, 1883, pp. 333-335, Pis. XLV-XLVI). 



Swammerdam, J. Ephemerae Vita (Amsterdam, 1675). 



Vayssiere, A. Recherches sur 1'orgauization des larves des Ephe- 

 meriues (Ann. Sc. Nat., xiii., 1882). 



