AMERICAN HYMEN0PTJ:RA. 191 



9. Cell III1+2 and beyond clouded ; fovea narrow, not reaching below antenna; 



middle metatarsus wider than tibia; abdomen finely roughened, seg- 

 ment 1 without, 2-4 with continuous white fasciae ; cell III5 short. 



nubecula. 

 Cell III1+2 and beyond without a distinct cloud 10. 



10. Fovea broad 13. 



Fovea narrow 11- 



11. Eye widely separated from fovea ; process large, semicircular ; joint 3 =^ 4 + 5, 



or nearly ; pubescence dense, ochraceous ; abdomen not fasciate..pruni. 



Eye and fovea contiguous; process small, rarely semicircular; pubescence 



thin, griseous ; abdomen with thin whitish fasciae 12. 



12. Cheek narrow, regularly rounded ; abdomen opake, finely roughened, with 



sparse rather coarse shallow punctures; enclosure finely roughened, 



except at base ; joint 3 = 4-6, or nearly arabis. 



Cheek broad, flat, subcarinate behind; abdomen shining, with minute sparse 

 punctures; enclosure, and metathorax beyond, rugose; joint 3 longer 

 than 4 + 5 platyparia. 



13. Abdomen impunctate, or nearly so = 16. 



Abdomen distinctly punctured, at least segments 1-2 14. 



14. Enclosure unusually rugose, sometimes truncate, narrow; po.stscutel bare, 



swollen ; abdomen with pubescence long, thinly subfasciate sayi. 



Enclosure ordinary ; postscutel pubescent 15. 



15. Pubescence fulvous, except the thin fasciae ; clypeus closely punctured, pubes- 



cent; tibiae and tarsi reddish ; abdomen opake corni. 



Pubescence thin, whitish ; clypeus shining, coarsely, sparsely punctured, 

 especially towards apex ; enclosure poorly defined ; abdomen shining, 

 thinly fasciate; vein IV3 arising before middle of cell III5 • .geranii. 



16. Abdomen with short pubescence, fasciate ; joint 3 = 4 + 5 19. 



Abdomen with long thin pubescence, subfasciate 17. 



17. Cheek subtriangular, produced to a rounded angle a little above middle of 



eye ; mesonotum and scutel opake mandibularis. 



Cheek regularly rounded ; joint 3 longer than 4+5 18. 



18. Hind tibia black, about equaling tarsus ; scopa with black hairs at base above ; 



enclosure more rugose; abdomen shining; fovea narrower. salicacea. 

 Hind tibia reddish, shorter than tarsus; disc of mesonotum and scutel shin- 

 ing ; enclosure less rugose ; fovea broader macoupinensis. 



19. Pubescence ochraceous; fovea extending as far as base of clypeus; abdomen 



opake, finely roughened, with thin ochraceous fasciae salicis. 



Pubescence griseous, thin; fovea narrower, not extending below antenna; 

 abdomen shining, with thin whitish fasciae ; resembles 0. bipunciata, 

 but the clypeus not shining northoscordi. 



MALES. 



Cheek broad and flat, presenting a rounded angle 10. 



Cheek regularly rounded and convex, without a rounded angle 1- 



1. Abdomen greenish or bluish; joint 3 longer than 5 8. 



Abdomen black '^• 



2. Cheek without black pubescence 4. 



Cheek with black pubescence ; joint 3 about as long as 5 3. 



TEANS. AM. ENT. SOC, XXVIII. JUNE, 1902. 



