Aphiochaeta. 213 



2. Frons higher than broad, shining; angle at fork acute . . nudipes Beck. 



— Frons broader than high, dull; angle at fork rect- 



angular, onter branch steep retroversa Wood. 



3. Scutelluni with six bristles 1. flavicoxa Zett. 



— Scutelluni with. four bristles (abnormally five or six) 4. 



4. Inner bristle of lower row nearly vertically below the 

 outer; posterior tibiæ, besides posterodorsal bristles, 



with a row of smaller anterodorsal bristles 5. 



— Inner bristle of lower row not vertically below the 



outer; posterior tibiæ with only posterodorsal bristles 7. 



5. 1 only slightly longer than 2; abdomen yellow with 

 black transverse bands, more or less interrupted 



in the middle 2. picta Lehm. 



— 1 considerably longer than 2 and generally longer 



than 2 + 3; abdomen mainly black 6. 



6. 1 equal to or a little longer than 2+3; hairs below 

 hind femora strong, few in number and not reaching 

 the middle; anal tube in male with two forwards 



curved spine-like bristles below near apex . Meigeni Beck. 



— 1 distinctly or considerably longer than 2+3; hairs 

 below hind femora less strong, generally more numer- 

 ous and reaching beyond the middle; anal tube in 



male without spines below 3. Giraudii Egg. 



7. Mesopleura bristly 8. 



— Mesopleura bare 24. 



8. Mesoj)leura with one or more longer bristles besides 



the small 9. 



— Mesopleural bristles uniform in size, all small 14. 



9. Mesopleura with two or three long bristles; arista 



short, not longer than the frons spinigera Wood. 



— Mesopleura with only one long bristle (in Palmeni 



rarely two) ; arista longer (except in hrunnea) 10. 



10. Front tarsi short and conspicuously thickened; third 



antennal joint in male very large Palmeni Beck. 



— Front tarsi simple or slightly thickened {paludosa); 

 third antennal joint in male, even if somewhat large, 



not so large 11. 



11. Antennæ red; balteres yellow; thorax more or less 

 brown, the longer bristle on mesopleura small (only 



female known) hrunnea Schmitz. 



— Antennæ black; balteres black or brown; thorax 



black, the longer bristle on mesopleura large 12. 



12. Legs pale; size 1,25 mm paludosa Wood. 



— Legs dark ; size 2—2,7 mm 13. 



13. Costa to middle of wing or beyond; balteres black. . 4. campestris Wood. 



— Costa 0,44 of the wing-length; balteres brown; male 



with only two scutellar bristles ciispidata Schmitz. 



14. Halteres dark to black 15. 



