156 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



plate covered with long setae and 

 narrowed and upturned at apex, fig. 



547 minutisimella, p. 157 



Claspers not forming a plate, figs. 548, 

 549 8 



10. Sclerotized plate of eighth sternite nar- 

 row and angular, fig. 550 



edalis, p. 158 



Sclerotized plate of eighth sternite 

 wide and arcuate, figs. 551, 552... 11 



Figs. 547-549. — Neotrichia, male genitalia. A, ventral aspect; B, lateral aspect; C, aedea- 

 gus, the basal portion omitted in 547 and 548. 



8. Apex of aedeagus flattened and elliptic, 



with a pair of long, apical setae; 

 apex of tenth tergite divided into a 

 pair of divergent, pointed, sclero- 

 tized lobes, fig. 548 vibrans, p. 159 



Apex of aedeagus flattened, but with 

 a membranous "thumb" instead of 

 setae; tenth tergite entirely mem- 

 branous, fig. 549 edalis, p. 158 



9. Eighth sternite with a heavily sclero- 



tized, arcuate or angular plate, figs. 



550, 551 10 



Eighth sternite without a sclerotized 

 plate, fig. 553 12 



11. Sclerotized plate of eighth sternite 



evenly arcuate along apical margin, 



fig. 551 riegeli, p. 159 



Sclerotized plate of eighth sternite 

 with a mesal emargination, fig. 552 

 falca, p. 159 



12. Eighth sternite with a large mesal 



body, angulate at apex, occupying 

 a full third of the width of the seg- 

 ment, fig. 553 kitae, p. 158 



Eighth sternite with mesal body either 

 much smaller, fig. 556, or of a dif- 

 ferent shape, fig. 554; note also 

 diff"erences in bursa copulatrix 13 



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