Tin'l'ETIDTE. 121 



o. Wings with colored markings not reticulate. .... 4 

 Wings hyaline or with the markings reticulate or spotted. . . 18 



4. Scutellum with six bristles. .... Hexach/T':ta Loew. 

 Scutellum not with six bristles 5 



5. Fourth longitudinal vein conspicuously curved forward at its tip. 



AcEOTOXA Loew. 

 Fourth longitudinal vein not conspicuously curved forward at its tip. 6 



(j. Distal portion of the wing with two hyaline indentations, separated by 

 a curved or arched brown projection from the brown oblique cross- 

 band or spot before it, the anterior indentation more slender, the 

 posterior one (in the second posterior cell, crossing or not the fourth 

 vein) more triangular in shape.* ...... 7 



Wings not so marked. ......... 10 



7. Body elongate; abdomen narrower than the thorax. 



Stkaussia Desvoidy. 

 Body short ; abdomen as broad as the thorax. .... 8 



8. Horizontal diameter of the eyes remarkably short. Stenopa Loew. 

 Horizontal diameter of the eyes not sliorter than usual. . . 9 



9. Antei)enultiuiate section of the fourth vein straight. Acidia, Loew. 

 Antepenultimate section of the fourth vein curved. Epocuroa Loew. 



10. Coloring of tlie body generally light, never black. ... 11 

 Coloring of the body black. . - 15 



11. Wings near the middle with two cross-bands, converging toward the 



posterior margin. ......... 1"2 



Wings not with such cross- bands. . . . - . . lo 



12. The third longitudinal vein is gently curved backward toward the tip ; 



head not swollen. . . , . . Spilographa Loew. 



Third longitudinal vein straight to the tip; head distinctly swollen. 



CEdicarena Loew. 



13. Wings with four very oblique cross-bands ; cross-veins very oblique. 14 

 Cross-bands nearly transverse, or dissolved into spots; cross-veins but 



little oblifjue Trypeta Meigen. 



14. Scutellum tumid, bituberculate. .... Peronyma Loew. 

 Scutellum of the usual structuie, not swollen, though convex. 



I'l-AGIOTOMA Loew. 



* In some varieties of Stniussiit Imujipinmix, the distal hyaline indenta- 

 tions are obsolete. 



1-3 



