FAMILY CHIKOXOMID.T: THE MIDGES 71 



KEY TO GENERA* 



1. Wings functional 2 



Wings greatly reduced, strap-like, not more than half as long as the 



abilomen (16) Eretmoptera Kellogg 



2. Second basal cell open apically 14 



Second basal cell closed 3 



3. Second vein either present and forked near tip or else indistinct or 



absent (Tanypodinse) 4 



Second vein not forked apically, simple, and always distinct (Dia- 

 mesinse) 10 



4. Costa not produced beyond end of third vein, wing hairy; fourth tarsal 



segment linear (Abiabesmyia Johannsen) (11) Pentaneura Philippi 



Costa distinctly produced beyond the end of the third vein 5 



5. Second vein wanting, the space between first and third veins broad; 



wings hairy 6 



Second vein present 7 



6. Fifth vein with long petiole (7) Trichotanypus Kieffer 



Fifth vein without petiole (Linacerus, Paratanypus) (15). 



Podonomus Philippi 



7. Fourth tarsal segment cordiform; wings bare, branches of fifth vein 



either with or without petiole (Coelotanypus) Clinotanypus Kieffer 



Fourth tarsal segment not cordiform ; wings hairy or bare 8 



8. Fifth vein not petiolate (6) Anatopynia Johannsen 



Fifth vein petiolate 9 



9. Petiole of fifth vein not one-third as long as the posterior branch; 



wings hairy Tanypus Meigen 



Petiole of fifth vein at least half as long as posterior branch of this 

 vein; wings bare or hairy (12) Procladius Skuse 



10. Posterior crossvein intersecting the petiole of the fifth vein; eyes bare; 



fourth tarsal segment cylindrical (14) Prodiamesa Kieffer 



Posterior crossvein intersecting the anterior branch of the fifth vein 

 near its base 11 



11. Fourth segment of tarsus more or less cordiform, shorter or at least 



not longer than the fifth 12 



Fourth tarsal segment cylindrical, longer than the fifth. 



Syndiamesa Kieffer 



12. Eyes finely pubescent; antenna? of male plumose (3) . . . .Diamesa Meigen 

 Eyes bare 13 



13. Legs annulate; male antennae not plumose (8) Heptagyia Philippi 



Legs not annulate Psilodiamesa Kieffer 



14. Terminal segment (style) of hypopygium of male directed rigidly back- 



wards; basal segment of anterior tarsi longer than the tibia, the 

 anterior tibia without distinct spur except in Pseudochironomus 



( Chironominse ) 25 



Terminal segment of hypopygium folded inwards; first segment of 

 anterior tarsus shorter than the tibia; anterior tibia with spur (Ortho- 

 cladiinje) 15 



* Checked by Dr. O. A. Johannsen. 



