30 A REVISION OF THE NEARCTIC SCIOMYZIDAE 



2. Second antenna! joint short, broad apically, narrow basally, triangular, 



not quadrate 3 



Second joint quadrare to rectangular, broad basally and apically; no pro- 

 pleural bristle 11 



3. Propleural bristle present and distinct 4 



Propleural bristle absent or microsopic 9 



4. Pteropleura bare 5 



Pteropleura pilose, setulose or bristly 6 



5. First vein bare or pubescent . . .• Dryomyza 



First vein bristly, at least apically Neuroctena 



6. Fore tibiae with two preapical bristles; epistoma strongly projecting. 



Sciomyza 

 Fore tibiae with only one preapical; epistoma at most weakly projecting. . . 7 



7. Clypeus very strongly exserted; long pilose species of the Arctic fauna. 



Oedoparea 

 Clypeus not exserted; sparsely pilose to bare species 8 



8. Frons shining to polished; slender, mostly shining black species. 



Dichrochira 



Frons opaque, or slightly shining anteriorly; robust, mostly opacjue tawny 



species Melina 



9. Mesopleura setulose; middle and hind femora with bristles. 



Achaetomelina 

 Mesopleura bare; femora without bristles 10 



10. Frons black; slender species with short wings Heteropteryx 



Frons tawny to yellow; robust species Renoeera 



11. Wings with numerous fuscous or dilute, spots 12 



Wings hyaline with, at most, only fuscous clouding along the costa and 



veins, rarely streaks between veins Chaetomacera 



12. Frons strongly convex medianly, polished; yellow species with large 



round, blackish spots Poecilographa 



Frons flat, opaque 13 



13. Eyes vertical or oblique 14 



Eyes horizontal; two frontal bristles present, both reclinate; sterno-and 



pteropleura setulose Trypetoptera 



14. Two frontal bristles present, but anterior one proclinate; second antennal 



joint with two well separated spines above; sternopleura with well devel- 

 oped bristle Hoplodictya 



Only one frontal bristle; second antennal joint with few closely set bristles 



or hairs above; sternoj^leura not bristly Monochaetophora 



1.5. Wings with numerous fuscous and diluted spots It) 



Wings, at most, fuscous only along veins, costa, or in streaks between 

 the veins 18 



16. Meso- and pteropleura bare; mesonotum irrorated, not vittatc 17 



At least |)teropl('ura setulose; mesonotum vittate Limnia 



17. Second aniciinul joint stout, flattened, rectangular, broad basally. 



Euthycera 

 Second joint slender, cylindrical Dietyomyia 



