4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



3. Wing entirely grayish; mesonotal pile whitish in male to yellow or golden in 



female, uniformly colored, at most with a poorly defined presutural vitta 

 that may be set off feebly by a very small amount of obscure, blackish pile; 

 flagellum of antenna wholly black to base. 



nigricornis James and Wirth, new species 



Wing yellowish on part or all of anterior half; tibiae wholly yellow; antenna 



with base of flagellum distinctly yellow or, if entirely black, a distinct 



presutural vitta of golden pile present 4 



4. Brassy pile of sublateral areas of second abdominal tergum forming a broad 



triangular area reaching almost to base of tergum and clearly visible as 



abdomen is rotated under light of varying incidence . . chrysopila Loew 



Brassy pile of sublateral areas of second abdominal tergum limited to the 



posterior margin melanderi James and Wirth, new species 



5. Second abdominal sternum largely or wholly pale in contrast to preceding and 



following sterna, second tergum likewise largely pale or with two translucent 



spots 6 



Second abdominal sternum largely concolorous with preceding and following 

 sterna and not translucent; second tergum with at most indefinite, non- 

 translucent pale areas 7 



6. Abdomen more than twice as long as wide; second abdominal tergum with 



a pair of translucent spots, separated in the female but sometimes fused 

 in the male; all tibiae largely black; mesonotal pile uniformly pale yellowish, 

 without a presutural vitta; guards of aedeagus united ventrally, not ter- 

 minating in setulae conjuncta James, new species 



Abdomen distinctly less than twice as long as wide; second abdominal tergum 

 with a broad, trapezoidal, semipellucid area taking in a large part of the 

 segment; only the hind tibia black or blackish apically; mesonotum with 

 a median presutural vitta, usually set off by adjacent vittae of short, 

 black pile; guards of aedeagus of the usual chrysopila group type, well 

 separated ventrally and terminating in setulae. 



subpellucida James and Wirth, new species 



7. Frons with a prominent inverted U-shaped impression, particularly prom- 



inent at the anterior extremes of its arms just above the frontal callus, 

 and shallowest where it crosses between the ocellar triangle and the ante- 

 ocellar tubercle; all tibiae largely black . . . impressa James, new species 

 Frons laterad of ante-ocellar tubercle concave transversely but not deeply 

 impressed, this concave area not extending conspicuously above the 

 ante-ocellar tubercle ; blackening of tibiae confined to apical half or third ... 8 



8. Scutellum yellow on posterior margin only; abdominal integument blackish, 



at most becoming reddish on parts of the terminal terga; dorsal abdominal 

 pile dense, particularly in male, that of terminal two terga at least almost 



completely covering background aurata Bellardi 



Scutellum with distal half yellow; abdominal integument in male usually 

 largely reddish or reddish brown on at least terga 3 to 5, less extensively or 

 not at all reddish to reddish brown in female; abdominal pile less dense, the 

 terminal terga by no means completely with background concealed ... 9 



9. Mesonotal pile wholly yellowish to whitish, the presutural vitta not at all 



differentiated in the female, but poorly differentiated in the male. 



eiseni Townsend 



Mesonotal pile yellow to golden, the presutural vitta well differentiated in 



both sexes and set apart from the other mesonotal pile by a vitta of black, 



pile on each side ryckmani James and Wirth, new species 



