THE CANADIAN ENTOMOLOGIST 105 



— Hind femur with long bristles confined to apical half of anteroventral sur- 



face; basal abdominal sternite bare 10. 



10. Abdomen with a black dorsocentral vitta; eyes short haired, almost con- 



tiguous Hebecnema lunbratica Meigen. 



— Abdomen with paired black dorsal spots; eyes not nearly contiguous. . . .11. 



11. Thorax with three pairs of postsutnral dorsocentral bristles; hind femur 



with antero-and posteroventral bristles ; mid tibia with two weak 

 anterodorsal bristles nigritc Malloch 



— Thorax with four pairs of postsutural dorsocentral bristles ; posteroventral 



surface of hind femur and anterodorsal surface of mid tibia without 

 bristles 12. 



12. Abdomen inconspicuously spotted; wings very conspicuously browned to- 



wards base and anteriorly; hind tibia without a bristle near base on 

 posterodorsal surface; eyes separated by less than width across poster- 

 ior ocelli nigricans Stein 



— Abdomen conspicuously spotted; wings hyaline; hind tibia with a setula 



near base on posterodorsal surface ; eyes separated by at least as great 



a distance as width across posterior ocelli diiplicata Meigen 



lv3. Thorax with four pairs of postsutural dorsocentral bristles 14. 



— Thorax with three pairs of postsutural dorsocentral bristles 24. 



14. Femora partly or entirely black 15. 



— Femora entirely pale 22. 



15. Eyes with dense long hairs; abdomen ovate, with dorsal paired spots and 



lateral checkerings 16. 



— Eyes bare or with very short sparse hairs; abdomen not as above 19. 



16. Hind femur without bristles on posteroventral surface; hind tibia with long 



bristles on entire length of anteroventral and posterior 



surfaces pectinata Johannsen 



— Hind femur with long slender bristles on basal half of posteroventral sur- 



face; hind tibia not as above 17. 



17. Thorax with one pair of long presutural acrostichal bristles; lateral mar- 



gins and ventral surface of scutellum bare orhitaseta Stein 



— Thorax without long presutural acrostichal bristles 18. 



18. Eyes separated by about the- width of anterior ocellus; ventral surface of 



scutellum bare rufitibia Stein. 



Eyes separated by at least the width across posterior ocelli ; ventral surface 

 of scutellum with sparse erect soft hairs brcris Stein 



19. Abdomen with a distinct black dorsocentral vitta; eyes sparsely haired, al- 



most contiguous above; hind femur without bristles on posteroventral 

 surface except near apex Ilcbccncma vespertina Fallen 



— Abdomen with distinct j^aired spots on dorsum 20. 



20. Third wing-vein bristly at base ; hind tibia with a \ery long anterodorsal 



median bristle, the apical dorsal one very 



weak Enoploptcryx anccps Zetterstedt* 



— Third wing-vein bare at base; apical dorsal bristle on hind tibia strong. 



nearly or quite a? long as the median anterodorsal one 21 



* Recorded by Stein but probably erroneously. 



