122 NORTH AMERICAN DIPTERA. 



15. Cross-veins conspicuously approximated 10 



Cross-veins not approximated 17 



16. Wings witli hyaline indentations and a subapical, arcuate, hyaline 



cross-band ; scutellum black. . . POLYMORPHOMYIA Snow. 



Wings with three brown bands or projections, connected anteriorly, 



the distal one following the costa, the middle one beyond the middle 



of the wing, the proximal one toward the base. CEDASPIS Loew. 



17. Scutellum with four bristles, yellow ; wings with black cross-bands. 



RHAGOLETIS Loew. 



Scutellum with two bristles, black; wings with hyaline indentations 

 along the margin. . ... . . ACUJRA Desvoidy. 



18. Fifth vein strongly bristly ; scutellum with six bristles. 



BLEPHARONECRA Loew. 

 Fifth vein not bristly ; scutellum with four or two bristles. . 19 



19. Wings banded on the apex. .... ACROT.ENIA Loew. 

 Wings not banded on the apex 20 



20. Face spotted 21 



Face not spotted. 22 



21. Wings very much dilated ; pattern of picture not radiating. 



ECTRETA Loew. 

 Wings not dilated ; with radiating markings along the margin. 



CARPHOTKICHA Loew. 



22. Front very broad 23 



Front not very broad 25 



23. Third antennal joint elongate, with a sharp anterior angle; ovipositor 



flattened ACIDOGONA Loew. 



Third antennal joint short 24 



24. Wings with numerous small spots and larger ones along the distal mar- 



gin; ovipositor conical. . . . . . EUROSTA Loew. 



Wings with large, irregular, brown spots and hyaline spaces. 



XBNOCH^:TA Snow. 



25. Wings without markings, or, on the apical half only with a reticulation 



dissolved into cross-bands. . . NEOASPILOTA Osten Sacken. 

 Flies not having the above characters. 2(5 



26. Wings of an evenly broad shape, and with an unusually blunt apex. 



ICTERIC A Loew. 

 Wings of the usual shape, or dilated. ...... 27 



27. Labella very much prolonged ENSINA Desvoidy. 



Labella not or but little elongated. . . ' . . . . 28 



