August, 1944 



Ross: Caddis Flies of Illinois 



247 



848C 



849B 



849A 



TARDA 



850A 



MARGINATA 



850B 



850C 



Figs. 846-850. — Triaenodes, male genitalia. A, lateral aspect; B, tenth tergite; C, claspers. 



12. Apex of claspers straight, tenth ter- 



gite sharply pointed, fig. 849 



tarda, p. 250 



Apex ot claspers bent mesad at a con- 

 siderable angle, tenth tergite spatu- 

 late, fig. 850 marginata, p. 251 



13. Cerci present as earlike lobes; ventral 



margin of lateral plates of tenth 

 segment angled to form a flat shelf, 



fig. 852. . . r 14 



Cerci absent, fig. 861; ventral margin 

 of lateral plates of tenth tergite not 

 angled 15 



14. Bursa copulatrix situated at the end 



of a long, flat stalk, fig. 851 



grisea, p. 249 



Bursa copulatrix sessile, attachments 

 short, fig. 852 frontalis, p. 249 



15. Plates of ninth sternite with ventral 



aspect forming a V with swollen 

 arms, lateral aspect pointed at both 



ends, fig. 853 aba, p. 249 



Plates of ninth sternite not shaped like 

 the above, figs. 854-861 16 



16. Apodeme of tenth segment long and 



sinuate, reaching far past bursa 

 copulatrix almost to sixth segment, 



fig. 854 perna, p. 250 



.Apodeme of tenth segment not reach- 

 ing bevond apex of bursa copulatrix, 

 fig'. 855 17 



17. .Apodeme above bursa copulatrix long, 



ending in a swollen, emarginate, scle- 

 rotized plate, fig. 855. . .injusta, p. 252 

 .Apodeme not extending above bursa 

 copulatrix, fig. 856 18 



