274 THE CANADIAN ENTOxMOI.OGlST 



3. Legs largely or entirely reddish or yellowish 4. 



Legs entirely black .- 5. 



4. Thorax with two pairs of strong presutural acrostichal bristles: mid tibia 



with one or two anterodorsal, and two posteroventral bristles besides 

 the posterodorsals conformis Malloch. 



Thorax with two pairs of weak presutural acrostichal bristles; mid tibia 

 without anterodorsal and posteroventral bristles latipennis Malloch. 



5. Thorax with three pairs of postsutural dorsocentral bristles 6. 



Thorax with four pairs of postsutural dorsocentral bristles 7. 



6. Mid tibia with an anteroventral and a posteroventral 



bristle melanderi Malloch . 



Mid tibia without an anteroventral and a posteroventral bristle sp.? 



7. Glossy black species, thoracic dorsum with lateral margins and a narrowly 



divided central vitta white pruinescent; arista almost bare; hind tibia 

 with two bristles on posterodorsal surface, the larger one apicad of the 

 smaller, situated at or just beyond middle of tibia; lower margin of 

 cheek gently curved in outline, with a very strong, upwardly curved 

 bristle before middle in addition to the other marginal 

 bristles johnsoni Malloch. 



Species not glossy black, at least the thorax with dense, uniform grayish 

 pruinescence; bristles on hind tibia not as stated above 8. 



8. Hind tibia with one posterodorsal bristle about one-third of the tibial 



length from apex, anterodorsal surface v/ith two bristles; face almost 

 vertical in profile, the mouth-margin but little produced, almost in 

 vertical line with base of antenna; ma,rgin of cheek with a few bristly 

 hairs, one or two of which, near anterior margin, are upwardly directed; 

 hal teres yellow innoams Zetterstedt. 



Hind tibia with two or more posterodorsal bristles 9. 



9. Halteres black; mouth-margin very much produced anteriorly, projecting 



very much beyond the vertical line of base of antenna; base of wings 

 not yellowish; abdomen not densely pruinescent. subrosfrakis Zetterstedt. 



Halteres yellow; mouth-margin not much produced anteriorly, hardly 

 projecting beyond the vertical line of base of antenna; wings yellowish 

 at bases; abdomen very densely pruinescent 10. 



10. Fore tibia with a strong bristle near apex on posteroventral 



surface septenirinnaUs Stein. 



Fore tibia without such bristle sphiiger Stein. 



N. B. — Holmgren's species frenaius which has been placed in Lasiops or 

 Trichopticus by authors belongs, according to my interpretation of generic 

 limits, to Phaonia. 



