138 PROC. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



6. Third tergite extending nearly to the middle of abdomen; pro- 



podeum without a distinct transverse carina mellea Ashmead 



Third tergite much smaller, not extending nearly to the middle 

 of abdomen; propodeum with a distinct straight, transverse 

 carina 7 



7. Abdomen strongly compressed from the sides; apical exposure of 



the third tergite distinctly longer than the second 



compressiventris n. sp. 



Abdomen not strongly compressed from the sides; apical exposure 

 of the third tergite equal to the second or no longer, .hegeli Girault 



8. Third tergite much the largest, occupying'most of the abdomen.. . . 9 

 Fourth tergite much the largest 10 



9. Face and orbits yellow or brownish yellow; pronotum and abdo- 



men brownish orbitalis Ashmead 



Head entirely black; pronotum and abdomen black 



insularis Ashmead 



10. Frons without distinct antennal depression 



gallicola Kieffer & Jorgensen 

 Frons with a distinct antennal depression. . '. 11 



11. Antennae, except the two proximal joints, white; mesonotum an- 



teriorly transversely striated albicornis Kieffer & Jorgensen 



Antennae not white, either brownish testaceous or blackish; 

 mesonotum coriaceous or shagreened, without striae 12 



12. Tegulae black; scape and flagellum for the most part dark brown 



or blackish, the former usually testaceous beneath; lateral 

 margins of the dorsal portion of pronotum rounded, not mar- 

 gined tegularis n. sp. 



Tegulae not black; scape and flagellum fusco-testaceous 13 



13. Lateral margins of the dorsal aspect of pronotum distinctly angu- 



lated and more or less distinctly margined above 14 



Lateral margins of dorsal aspect of pronotum not distinctly angu- 

 lated or margined, but more or less rounded., .cecidomyiae Ashmead 



14. Ocellocular line very distinctly shorter than the postocellar line, 



only slightly more than half as long; striations of the face not 

 extending upward along the inner margin of the eye much be- 

 yond the lower edge of antennal depression; abdoriien scarcely 

 acuminate at apex; first antennal ring-joint transverse 



similaris n. sp. 



Ocellocular and postocellar line practically equal; some of the 

 striations of face extending upward along the inner eye-margin 

 beyond the lower edge of antennal depression; abdomen dis- 

 tinctly acuminate at apex; first antennal ring-joint as long as 

 broad. . . .americana Girault 



