96 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



Clasper receptacle tubular, fig. 387C-/ 45 

 45. Clasper receptacle directed nearly 

 anterad, diagonal to segment, fig. 

 387C, D 46 





Fig. 388. — Hydropsyche, lateral lobe of fe- 

 male eighth sternite. J, bifida; B, recurvata; 

 C, cuanis; D, phalerata; E, betteni. This set 

 is drawn at right angles to the face of the lateral 

 lobe. 



Fig. 389. — Hydropsyche, female eighth 

 sternite. A, scalaris; B, incommoda. 



Fig. 390. — Hydropsyche scalaris, female gen- 

 italia, ventral aspect. 



Fig. 391. — Cheumatopsyche campy la, female 

 genitalia, ventral aspect. 



Clasper receptacle directed or curved 

 dorsad or posterad, fig. 3S7E-I . . . 47 



46. Clasper receptacle narrow and trun- 



cate at tip, fig. 387C 



recurvata, p. 99 



Clasper receptacle wider and rounded 

 at tip, fig. 387D cheilonis, p. 98 



47. Clasper receptacle long, the anterior 



side of its entrance channel with a 

 long, overhanging flange, x, fig. 



387£ morosa, p. 98 



Either clasper receptacle much shorter, 

 or the anterior side of entrance chan- 

 nel with only an inconspicuous 

 flange, fig. 387G 48 



48. Posterior side of entrance channel to 



clasper receptacle with a sinuate 

 overhanging flange, y, fig. 3S7F. . . 



sparna, p. 97 



Posterior side of entrance channel 

 with no flange extending down ven- 

 tral portion 49 



49. Entrance channel reduced to a narrow 



slit, fig. 387G slossonae, p. 99 



Entrance channel much wider, fig. 

 387//, / 50 



50. Clasper receptacle long, narrowed and 



with tip markedly curved, fig. 387/ 



bifida, p. 97 



Clasper receptacle shorter and more 

 bulbous 51 



51. Clasper receptacle situated near mid- 



dle of tergite vexa, p. 97 



Clasper receptacle situated along lower 

 edge of posterior side of tergite, fig. 

 387// piatrix, p. 97 



Bifida Group 

 Hydropsyche walkeri Betten & Mosely 



Hydropsyche maculicornis Walker (1852, p. 

 113); c?". Preoccupied. 



Hydropsyche walkeri Betten & Mosely (1940, 

 p. 23). New name. 



To date this species has not been discov- 

 ered in Illinois, although it may eventually 

 be taken in the northern part of the state. 

 It was originally described from Ontario; 

 we have additional specimens from New 

 York, Quebec and Wisconsin. 



Female. — Length 10 mm. In color and 

 general structure similar to male, which in 

 these characters is practically indistinguish- 

 able from bifida, described below. Female 

 genitalia, fig. 387^, with clasper groove 

 well marked, wide and curved at apex, the 

 upper portion of the groove partly invagi- 

 nated beneath dorsal cap of ninth tergite; 

 lateral lobe long but narrow, with abundant 



