246 NORTH AMERICAN ANTHOMYIID FLIES OF GENUS PHAONIA 



55. Thorax with a pair of presutural acrostichal bri^stles; prealar bristle long. 



solitaria Stein 



— Thorax without differentiated presutural acrostichal bristles 56 



56. Humeri not paler than adjoining portions of dorsum of thorax. 



apicata Johannsen 



— Humeri yellowish testaceous at least in part 57 



57. Prealar bristle not over half as long as the bristle behind it; tarsi black; 



eyes of male separated by width across posterior ocelli . . bysia (Walker) 



— Prealar bristle over half as long as the one behind it; tarsi yellow; eyes 



of male separated by more than width across posterior ocelli; longest 

 hairs on arista longer than width of third antennal segment. 



winnemanae Malloch 



58. Prealar bristle minute or absent; thorax and abdomen glossy lilack, with 



faint gray pruinescence; legs, except tarsi, yellow; hind tibia with two 

 anterodorsal bristles in each sex parviceps ^lalloch 



— Prealar bristle almost or quite half as long as the bristle behind it. . . .59 



59. Hind tibia with two equally long anterodorsal bristles; third wing-vein 



not setulose at base below; longest hairs on arista not as long as width 

 of third antennal segment; shining black species with distinct but not 

 very dense grayish pruinescence on thorax and abdomen; cross-veins 

 of wings not noticeably inf uscated 60 



— Hind tibia either with one anterodorsal bristle or with one long and one 



very short bristle on that surface; longest hairs on arista distinctly 

 longer than width of third antennal segment except in prisca 8tein; 

 subopaque black species, with very dense gray pruinescence; third wing- 

 vein sometimes with some weak setulae at base below 61 



60. Third antennal segment in male normal, not abnormally large and broad; 



fore tibia in male without median posterior bristle; mid tibia with one 

 posterior bristle basad of middle; some fine hairs at base of posterior 

 notopleural bristle trivialis new species 



— Third antennal segment in male very large and broad, not as noticeably 



so in female; fore and mid tibiae in both sexes with two posterior bristles; 

 no hairs at base of either of the notopleural bristles. 



laticornis new species 



61. Hind tibia with the apical posterodorsal bristle as strong and large as the 



anterodorsal and nearly as large as the dorsal one (fig. 22); mid 

 femur with one bristle basad of middle on posteroventral .surface; 

 third vein setulose at base below; cross-veins infuscated. 



atlanis new species 



— Hind tibia with the apical posterodorsal bristle much smaller and weaker 



than the anterodorsal one; mid femur with more than one postero- 

 ventral bri.stle 62 



62. Cro.ws-veins of wings distinct!}', often conspicuously, infuscated; third 



vein often with some weak setulose hairs at base below; hind tibia 

 usually with one long and one very short bristle on anterodorsal surface; 

 hind femur without distinct bristles on posteroventral surface. 



fusca Stein 



