90 ILLINOIS BIOLOGICAL MONOGRAPHS [408 



25(22) 



26(21 



27(32 

 28(29 



29(28 



30(31 



31(30 



32(27 

 33(34; 



34(33 



35(36 



36(35 



37(42 

 38(39 



39(38 

 40(41 

 41 (40 

 42(37 



Tenth abdominal tergum with markings not extending the entire length and not 

 dumbbell-shaped; antennae with segments 2 and 3 incomplete; folded portion of leaf 



irregularly wrinkled; often both edges folded; Y-139-1-1 Pontania sp. 9. 



Ninth abdominal tergum with some markings or spots; antennae with segment 3 



usually complete . , 27. 



Ninth abdominal tergum with two transverse rows of minute colored spots 28. 



Tibia longer than femur; front concolorous with vertex; setae on abdominal terga 



more than three times as long as spiracles; Y-166-1-1 Pontania sp.10. 



Tibia subequal in length to femur; front not concolorous with vertex but darker; setae 



on abdominal terga less than three times as long as spiracles 30. 



Head blackish; mature larvae 9 mm. in length; on Salix; Y-8.46(?)-l-2 



Pontania sp. 11. 

 Head brownish; mature larvae 11 mm. in length; on Populus; M-166 



Pontania sp. 12. 

 Ninth abdominal tergum without two transverse rows of minute colored spots .... 33. 

 Ninth abdominal tergum with two pairs of transverse blackish or brownish markings, 

 interrupted on meson; head brownish with area along epicranial suture distinctly 



clear and paler; Y-142-1 derosa MacGillivray. 



Ninth abdominal tergum with one pair of transverse blackish or brownish markings, 

 interrupted on meson; head blackish or brownish in younger specimens, yellowish 

 or light brown in older specimens with area along epicranial suture not distinctly 



paler 35. 



Tenth abdominal tergum with markings not reaching the paired caudal protuberances 

 but broken on caudal half into minute spots; head yellowish with two minute brown 

 spots on front; leaf-edge folder, folded edges not irregularly wrinkled; M-146. 



Pontania sp. 13. 

 Tenth abdominal tergum with markings reaching the paired caudal protuberances, 

 not broken on caudal half into minute spots; yellowish or brownish without two 



minute brown spots on front 37. 



Ninth abdominal tergum with paired markings on its cephalic half 38. 



Ninth abdominal tergum with a transverse row of minute spots caudad of paired 

 markings; leaf-edge-folder; both edges often folded and folded portion irregularly 



wrinkled; M-145 Pontania sp. 14. 



Ninth abdominal tergum without a transverse row of minute spots caudad of paired 



markings 40. 



Antennae with segment 3 incomplete; only one edge of leaf-folded, folded portion not 



irregularly wrinkled; M-89,-147 Pontania sp. 15. 



Antennae with segment 3 complete; both edges of leaf folded, folded portion irregu- 

 larly wrinkled; M-116,-144 Pontania sp. 16. 



Ninth abdominal tergum with paired markings on caudal half; antennae with 

 segment 3 complete; single edge-folder, folded portion not irregularly wrinkled; 

 Y-8.46(?)-2-2 (in part) Pontania sp. 17. 



Nematid genus 1. — Larvae small, greenish; body cylindrical, tapering 

 uniformly toward caudal end; segmentation distinct; annulation indistinct; 

 third abdominal segment apparently with four annulets, annulets 1, 2, and 

 3 setiferous; thoracic legs conspicuously long, nearly as long as thorax, 

 slender, with trochanter longer than femur; larvapods well developed, 

 setiferous; tenth abdominal segment without the paired caudal protuber- 

 ances; head circular, front flattened, smaller than thorax in width and 



