19. Furcation of fifth vein more distal than that of the fourth. 



Exechia. 

 Furcation of the fourth vein more distal than that of the fifth. 



Rhymosia. 



20. Furcation of the fifth vein more distal than the junction of the 



fourth -with the anterior cross-vein. ..... 21 



Furcation of thefifih vein more proximal than the junction of the 

 fourth with anterior cross-vein. . . Brachycampta. 



21. Furcation of fifth vein more distal than that of the fourth. 



Mycothera. 

 Furcation of fourth vein more distal than that of the fifth. 



Allodia. 



1. Wings and halteres wholly wanting. . . Epidapus 9- 

 Wings and halteres as usual. ....... 2 



2. The fourth vein springs from the third at an angle, i. e. the anterior 



cross-vein is obsolete. , Epidapus $ . 



Anterior cross-vein not obsolete. ...... 3 



3. Proboscis much elongated, longer than the thorax. Eugnoriste. 

 Proboscis short. ......... 4 



4. Wings very distinctly hairy; claws not denticulate. Trichosia. 

 Wings bare or slightly hairy. ....... 5 



5. Antennal joints of male pedicillate and with whorls of hair; forks 



of fourth vein arcuate. ..... Zygoneura. 



Antennal joints not pedicillated, bare or with short hairs. . 6 



6. Claws denticulate. ....... Odontonyx. 



Claws not denticulate. ........ 7 



7. Face strongly produced ...... Rhynchosciara. 



Face not produced. ........ Sciara. 



Additional Generic References. 



Odontonyx Ruebsaamen, Berlin. Ent. Zeit. xxxix, 25, 1894. 

 Mexico. 



Rhynchosciara Ruebsaamen, 1. c. Mexico. 



