SCENOPINIDAE OF THE WORLD 167 



4. Abdominal segments black-brown with white posterior margins 



B. halli, new species 

 Abdominal segments red-brown with creamy posterior margins 



B. ordwayi, new species 



5. Wing smoky brown 6 



Wing smoky white 7 



6. Halter knob tan B. hodgdeni, new species 



Halter knob tan with cream ventral surface . . . B. griffini, new species 



7. Halter knob white 8 



Halter knob cream or tan 10 



8. Abdomen pristine white 9 



Abdominal segments black with white posterior margins . B. insulana (Cole) 



9. R4 branching beyond r-m cross vein equal length of r-m 



B. addacifons, new species 

 R4 branching beyond r-m cross vein twice length of r-m 



B. castanea, new species 



10. Halter knob tan H 



Halter knob cream 13 



11. Halter knob all tan 12 



Halter knob tan above cream below, abdominal segments red-brown with 



cream posterior margins B. yucatani, new species 



12. Abdomen white B. pruinosa, new species 



Abdomen cream with central red-brown "T"s . . . B. griseoia (Coquillett) 



13. Halter knob all cream 14 



Halter knob cream, marked or lighter below, or yellow 18 



14. Abdomen marked with brown or cream 15 



Abdomen white above B. boharti, new species 



15. Abdomen white with narrow anterior brown bands 16 



Abdomen red-brown 17 



16. R4 branching beyond r-m about length of r-m . . . B. davisi, new species 

 R4 branching beyond r-m twice length of r-m . . . B. downeyi, new species 



17. Abdomen with central red-brown "T"s fading to white 



B. coquilletti, new species 

 Abdomen with segments red-brown with posterior bands cream 



B. beameri, new species 



18. Halter knob white or yellow below 19 



Halter knob with tan margins B. timberlakei, new species 



19. Halter knob white below B. minuta, new species 



Halter knob yellow below 20 



20. Abdomen yellow with black basal bauds B. helenae (James) 



Abdominal segments brown with creamy margins . B. schlingeri, new species 



Key to Species of Brevitrichia (females) 



1. Wing hyaline 2 



Wing smoky brown or white 10 



2. Halter knob tan, cream or orange 3 



Halter knob white, 7 spines on 8th tergum B. fiocki, new species 



3. Halter knob cream 4 



Halter knob tan or orange 8 



4. Halter knob all cream 5 



Halter knob cream above tan below, 8th tergum with 7 spines 



B. downeyi, new species 



