FAiMILV STKKBLID.E THE BAT FLIES 479 



3. Ctenidium extending to the sides of the head and visible laterally from 



dorsal view 3a 



Ctenidium ending far before the sides of the head (E. breviceps, 

 Panama) Eldunnia, n. g. 



3a. Posterior femora about twice as long as the anterior ones; anterior 



cross-vein before the middle of the wing (1) Strebla Wiedemann 



Posterior femora decidedly less than twice as long as the anterior ones; 

 anterior crossvein beyond the middle of the wing (2). 



Euctenodes Waterhouse 



4. Wings entirely lacking 5 



Wings present, though small 6 



5. Posterior legs about twice as long as the anterior ones. 



Megistopoda Macquart 

 Posterior legs not twice as long as the anterior ones. 



Paradyschiria Speiser 



6. Wings of normal size 8 



Wings small, narrow or short 7 



7. Wings erect and narrow; posterior legs about twice as long as anterior 



ones (5, also text figure) Pterellipsis Coquillett 



Wings lying flat, short; posterior legs not twice as long as anterior 

 ones (4) .> Aspidoptera Coquillett 



8. Wings with a single crossvein and three longitudinal veins; thorax com- 



pressed (3) Nycterophilia Ferris 



Wings with at least two crossveins and six longitudinal veins; thorax 

 depressed 9 



9. Posterior legs at least twice as long as the anterior pair 10 



Posterior legs obviously less than twice as long as the anterior pair 



( 6 ) Trichobius Gervais 



10. Posterior legs three times as long as the body. .Paratrichobius Costa Lima 

 Posterior legs about twice as long as the front pair Speiseria Kessel 



Stieblidas II. — 3, Nycterophilia coxata; 4, Aspidoptera ininuta; 5, Pterellipsis aranea; 

 6, Trichobius sparsus. 



