232 NORTH AMERICAN ANTHOMYIID FLIES OF GENUS PHAONIA 



2. Prosterniim bare; the bristle on posterodorsal surface of hind tibia (calcar) 



at or near middle of tibia Steinella Malloch 



— Prosternum hairy; calcar about one-third of the tibial length from apex of 



hind tibia 3 



3. Fourth wing- vein not curved forward at apex Smithomyia Malloch 



— Fourth wing- vein curved forward at apex Poecilophaonia Malloch 



4. Pteropleura with many fine erect hairs in center 5 



— Pteropleura bare 6 



5. Pi-osternum hairy Polietes Rondani 



— Prosternum bare Pseudophaonia ^Malloch 



6. Fourth wing-vein curved forward at apex; third vein setulose at base 



both above and below Bigotomyia Malloch 



— Fourth wing- vein not or almost imperceptibly curved forward at apex; 



third vein not setulose on both sides at base 7 



7. Cheek in male with one or two very strong upwardly curved bristles on 



lower mai'gin just below anterior margin of eye in both sexes; frons 

 in female with the anterior supraorbital bristle very strong and directed 

 forward, the interfrontalia with or without a pair of cruciate bristles. 



Dendrophaonia new genus 



— Cheek in both sexes without strong upwardly curved bristles as above, 



sometimes with some upwardly curved fine hairs or setulae; lower 

 supraorbital bristle weak or absent, if present not directed forward. .8 



8. Hypopleura with some fine hairs on upper margin in front of spiracle; 



prealar bristle very long; fore tarsus with some long fine sensory hairs 

 along the posterior or postero ventral side of basal segment; eyes dis- 

 tinctly hairy; presutural acrostichals not strong; third wing- vein bare. 



Phaonia R.-D. sen. str. 



- — Third wing- vein setulose at base below; thorax with some well developed 



presutural acrostichals; hypopleura with some weak liairs on upper 



margin in front of spiracle subgenus Rohrella R.-D. 



— Third wing- vein bare at base or the other characters not as above 9 



9. Fore tarsus in both sexes with the segments short and stout, the basal 



one densely hairy, the hairs erect, no long sensory hairs along posterior 

 side; hypopleura hairy on upper margin in front of spiracle. 



Phaonia (group serva) 



— Fore tarsus not as above, generally slender and with or without fine 



sensory hairs along posterior side; hypopleura hairy or bare 10 



10. Hypopleura usually with a few fine hairs below sjjiracle; presutural acro- 



stichal bristles well developed Subgenus Euphemia R.-D. 



— Hypopleura l)are; presutural acrostichals strong; female with a strong 



pair of cruciate bristles; metallic blue speciies Euphaonia Malloch 



— Hypopleura bare; presutural acrostichals poorly developed 11 



11. Arista with very distinct hairs; legs largely yellowish. 



Phaonia (group fusca) 



— Arista almost bare, the hairs very seldom as long as basal diameter of 



arista; legs black Phaonia (grouji minima) 



