NEUROPTERA. 



417 



ceiving food The larvae have, at the end of their bodies, two long 

 threads, which remain in the perfect Perla (Fig. 387), but not in the 



Fig. 387. — Perla bicaudata. 



Fig. 



•Nemoura variegata. 



Fig. sSg.^Nemoura variegata (larva). 



perfect Nemoura; the latter lose the two caudal hairs when they 

 arrive at the adult state (Figs. 388, 389). One species of Perla is 

 very common on the quays of Paris. 



The EphemeridcE^ or May-Fly family, have long, slender bodies, 

 71 



