THE CANADIAN ENTOMOLOGIST 317 



tion first costal division (that beyond humeral Vein) ove,r 

 half as long as second ; interfrontalia entirely reddish ; 

 orbital and dorso-central bristles weak; proboscis and palpi 



fuscous; food-plant unknown. Ill alhidohalterata Malloch. 



Last section of fifth vein subequal to preceding section; first 



costal division half as long as second; interfrontalia infus- 



cated on upper half; orbital and dorso-central bristles 



strong; proboscis and palpi orange-coloured. Food-plant 



unknown. D. C, Pa., Ill varifrons Coquillett. 



10. Lateral margins of mesonotum broadly pale yellow 11 



Lateral margins of mesonotum narrowly, or not at all, \el- 



low, the pale colour confined almost entirely to the suture 

 or to the extreme upper margin of the pleurae 12. 



11. Frons with the centre stripe pale yellow; orbits sometimes 



blackened posteriorly; legs black, knees never yellow. 

 Larvae mining leaves of Malva, Verbena, Solidago, Helicni- 



thiis, etc. General .jucunda V. d. W'ulp. 



Frons with centre stripe more or less blackened; legs with 

 knees pale yellow. Larvae mining leaves of oats, wheat 

 and other cereals. General coquilletti Malloch. 



12. Palpi yellow. Food-plant unknown. 



General longipennis Loew. 



Palpi black 13. 



13. Lengs entirely black 13. 



Legs in part yellow 15. 



14. Shining black species, very slightly dusted ; interfrontalia yel- 



low; thoracic bristles very long; 4 pairs of strong dorso- 

 centrals; last section of fourth vein three times as long as 

 preceding section. Food-plant unknown. 

 Mont rutiliceps Melander. 



Opaque black, pollinose species; thoracic bristles distinct from 

 setulae; abdomen entirely black; frons reddish anteriorly, 

 black posteriorly. Larvae mining in cambium of Amelan- 

 chier canadensis. W. Va amelanchieris Greene. 



Opaque black,- pollinose species; interfrontalia yellow; thoracic 

 setulae long, dorso-centrals scarcely distinguishable from 

 them except the posterior pair; last section of fourth veh\ 



