62 THE CANADIAN ENTOMOLOGIST 



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• — Eyes of male separated by as great a distance as width across posterior 

 ocelli; characters not in all respects as above 5. 



5. Males .• 6. 



 — Females 11. 



6. Calyptrae dark brown; eyes separated by one-third of the head-width; 



frons velvety black; hind femur with bristles on entire length of postero- 

 ventral surface veliitina Malloch. 



— Calyptr?e whitish or yellowish; species not as above in other respects 7. 



7. Small species, not over 4 mm. in length, densely white pruinescent; pre- 



sutural acrostichals strong, two-rowed; females of known species 

 without paired spots on abdomen, and the genitalia with two or four 

 short thorns at apex 8. 



— Larger species, over 5 mm. in length, brownish gray pruinescent; presutural 



acrostichals in at least three series; females without thorns on 

 genitalia 9. 



8. Fourth abdominal tergite distinctly longer than third; cheek but little 



higher than width of parafacial at base of antenna; abdomen silvery, 

 third tergite without paired spots... argentiventris Malloch. 



— Fourth abdominal tergite not longer than third; cheek twice as high as 



width of parafacial at base of antenna; abdomen whitish gray, not 

 silvery, third tergite with a pair of small spots hrevicornis Malloch. 



9. Hind femora with long bristles on antero- and posteroventral surfaces, 



those on the latter finer than on the former, and not extending to 

 base novce-anglce Malloch . 



— Hind femora with at most very short bristles on posteroventral surface, 



those on anteroventral long and strong, but confined to apical half.... 10. 



10. Hind femur with a number of short, erect bristles on median portion of 



posteroventral surface; eyes separated by less than width across 

 posterior ocelli; each orbit as wide as mterirontaVia . . gibsoni Malloch. 

  — Hind femur without median posteroventral bristles; eyes separated by 

 width across posterior ocelli; each orbit about half as wide as 

 interfrontalia monticola Malloch. 



11. Lower calyptra hardly protruding beyond upper; costal setulse longer than 



diameter of costal vein obsoleta Malloch. 



-^ Lower calyptra projecting much beyond upper; costal setulse not as long 

 as diameter of costal vein 12. 



12. Small species, not over 4 mm. in length; thorax and abdomen with grayish 



white pruinescence, without dorsal spots; genitalia of female with 



some strong apical thorns hrevicornis Malloch. 



 — Larger species, averaging over 5 mm. in length; thorax and abdomen with 

 brownish pruinescence, the former vittate, the latter with paired 

 dorsal spots - nohilis Stein. 



13. Presutural acrostichals consisting of two very closely placed, rather irregular 



series of short setula?; abdomen with a linear dorsocentral black vitta 

 and black paired dorsal spots; basal segment of hind tarsus a little 

 less than half as long as hind tibia; basal separation of antenna? 

 linear tetrachcsta Malloch, 



— Presutural acrostichals consisting of four or more series of fine hairs; 



