82 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



narrow with straight hind margin, 

 much different in shape from hind 

 wings, which have the hind margin 

 arcuate, fig. 334 11 



10. Both wings with apical margins in- 



cised; front wings with first fork of 

 Rg as far basad as first fork of M, 



fig. 332 Oropsyche, p. 83 



Both wings with apical margins evenly 

 rounded; front wings with first fork 

 of Rs distad of first fork of M, fig. 

 333 Aphropsyche, p. 83 



11. Malar space wide, fig. 328; flagellum 



with first two segments partly or 

 completely fused, fig. 328; body and 

 wings straw color with tawny or 



light brown on dorsum 



Potamyia 9, p. 85 



Malar space narrow, fig. 329; flagellum 

 with first two segments always sep- 

 arated by a distinct annular suture; 

 body and wings darker, wings either 



dark or irrorate, figs. 392, 393 12 



Males 13 



Females 14 



Base of aedeagus cylindrical, figs. 358- 



383 Hydropsyche, p. 86 



Base of aedeagus bulbous, figs. 394- 



403 Cheumatopsyche, p. 108 



14. Sternal plates of eighth segment sep- 

 arated to base of segment, fig. 391 

 Cheumatopsyche, p. 13 



12 



13 



Hydropsychidae Wings 



Fig. 330. — Smicridea fasciatella. 

 Fig. 331. — Diplectrona modesta. 

 Fig. 332. — Oropsyche howellae. 



Fig. 333. — Aphropsyche aprilis. 

 Fig. 334. — Hydropsyche simulans. 

 Fig. 335. — Macronemum zebratum. 



