42 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 74 



2. Mid femur without strong bristles on any part of posteroventral surface. _ 5. 

 Mid femur with strong bristles on part of the posteroventral surface, which 



are not longer than the femoral diameter 3. 



3. Prealar bristle less than half as long as the bristle behind it ; intra-alar 



bristle quite long anthrax Malloch. 



Prealar bristle over half as long as the bristle behind it 4. 



4. Thoracic dorsum yellowish testaceous ; male hypopygium as Figure 31. 



semibrunnea (de Meijere). 

 Thoracic dorsum largely blackish ; male bypopygium as Figure 82. 



nmbrosa, new species. 



5. Bases of wings distinctly infuscated ; hypopygium as Figure 33. 



fumibasis Malloch. 

 Bases of wings not infuscated 6. 



6. Thorax, abdomen, and femora, mostly fuscous, anterior margin of thorax 



yellowish; male hypopygium as Figure 34 gedehi (de Jleijere). 



Thorax and legs testaceous yellow, abdomen shining black; face aud frons 

 largely fuscous 7. 



7. Wings with very slight indications of clouding over the cross veins, and no 



dark cloud over any of the other veins apically. 



obscuriceps (de Meijere). 



Wings with at least the cross veins distinctly clouded, a large fuscous cloud 

 over apices of second and third veins, and a less elongate cloud over apex 



of fourth vein 8. 



S. A more or less evident cloud over lower extremity of inner cross vein, and 

 the apical clouding less extended basally ; hypopygium as Figure 35. 



kocki Malloch. 

 No cloud over inner cross vein, and the apical clouding more extended 



basally ; male hypopygium as Figure 3G nigrofulva Malloch. 



9. Fourth wing vein quite noticeably curved forward at apex (Griphoneu- 



roides, new subgenus) 10. 



Fourth wing vein not evidently curved forward at apex, usually straight, and 

 parallel with third, rarely gradually and very slightly convergent with it 

 on entire apical section 19. 



10. Head black or fuscous ; fourth wing vein usually very conspicuously curved 



forward at apex (fig. 37) H- 



Head testaceous yellow; fourth vein inconspicuously curved forward at 

 apex (fig. 38) 17. 



11. Antennae entirely black, fuscous, or dark brown 12. 



Antennae yellow, at most with apex of third segment darkened 14. 



12. Thoracic dorsum and scutellum entirely dull testaceous yellow, without any 



dark markings; femora black; wings with outer cross vein and apical sec- 

 tion of veins 2 to 4 faintly margined with brown. 



obscurlcornis (de Meijere). 



Thoracic dorsum with a broad dark central viita, scutellum red-brown, 

 darker in middle astrolabe! (Kertesz). 



Thoracic dorsum with a broad dark central vitta which is not shai-ply 

 margined, scutellum dark brown or fuscous at apex, becoming paler 

 basally 13. 



13. All femora rufous yellow, fore and hind tibiae and all tarsi more brownish ; 



wings slightly yellowish, outer cross vein and apex of second vein faintly 

 bordered with yellow; halteres yellow; length 8 mm__ wallacei (Malloch). 

 Legs reddish brown, hind femora and tips of tibiae and tarsi darker; 

 wings pale yellowi.sh bi'owu tinged, especially on costa, apices of veins 

 2, .3, and 4, each with a brown spot ; knobs of halteres brown ; length 

 6 mm atricornis (Kertesz). 



