No. 64] DIPTERA OF CONNECTICUT : TAXONOMY 177 



TABLE OF FAMILIES 



1. Wings absent or greatly reduced 92 



Wings present, rarely reduced 2 



2. Antennae composed of six or more freely articulated segments 3 



Antennae composed of not more than five freely articulated segments, 



the third segment sometimes complex, usually bearing a style or 

 arista 22 



3. Mesonotum with an entire V-shaped suture 4 



Mesonotal suture transverse, not V-shaped 7 



4. Ocelli absent 5 



Ocelli present TRICHOCERIDAE 



5. Only one anal vein reaches the wing margin 6 



Two anal veins reach the wing margin TIPULIDAE 



6. Second and third veins each with two branches (radius 5 branched). 



TANYDERIDAE 

 Second and third veins with only three branches reaching the wing 

 margin (radius 4-branched) PTYCHOPTERIDAE 



7. Wings without a network of folds or creases 8 



Wings with a network of fine folds or creases BLEPHARICERIDAE 



8. Ocelli present 9 



Ocelli absent 14 



9. Costa continuing around the wing, although weakened behind. 



CECIDOMYIDAE 

 Costa ending at or near the wing-tip 10 



10. Discal cell present 21 



Discal cell absent 11 



11. Tibiae with apical spurs 12 



Tibiae without apical spui-s, though sometimes produced spur like 11a 



11a. Basal cells open apically; only anterior veins heavy SCATOP3IDAE 



Basal cells, long, closed apically; veins strong (Axymyia). 



ANISOPODIDAE 



12. Eyes more or less connected by a projection above the base of the 



antennae SCIARIDAE 



Eyes separated 13 



13. Antennae placed below the compound eyes, usually close to the oral 



margin BIBIONIDAE 



Antennae situated at most slightlv below the middle of the compound 

 eyes M YCETOPHILIDAE 



14. Costa continued around the margin of the wings, though weaker be- 



hind the apex 1'^ 



Costa ending at or near the apex of the wing 15 



15. Wings very broad, "the posterior veins weak and poorly developed. 



SIMULIIDAE 

 Wings narrow and long, the posterior veins stronger 16 



16. Wings lying flat over the back when at rest; metanotum short and 



without a longitudinal groove; femora sometimes swollen. 



CERATOPOGONIDAE 



Wings lying roof-like over the back when at rest; metanotum long and 

 with a median longitudinal groove; legs long and slender. 



CHIRONOMIDAE 



17. Wings short and broad, folded roof-like over the body when at rest, 



usually pointed PSYCHODIDAE 



Wings long, or if broad, the apex very broadly rounded, always lying 

 flat over the back when at rest 18 



18. Venation very much reduced, several of rhe veins lacking. 



CECIDOMYIDAE 



Venation not reduced, the veins strong 1" 



19. Basal cells long, extending to or beyond the middle of the wing 20 



Basal cells, especially the second, short, not extending nearly to the 



middle of the wing THAUMALEIDAE 



