520 M. W. R. de V. GRAHAM 



length of pedicellus and flagellum about equal to breadth of head. Reticu- 

 lation of disc of scutellum about as coarse as that of the frenum 



H. musaeus (Walker) (p. 540) 



- Antennal scape reaching at most slightly above the lower edge of the median 



ocellus, if reaching slightly above the lower edge, then postmarginal vein 

 slightly shorter than the marginal vein, and combined length of pedicellus 

 and flagellum 1-25 to 1-3 times breadth of head. Reticulation of disc of 

 scutellum very fine, at least slightly finer than that of the frenum . . 39 



39 (38) Antenna with combined length of pedicellus and flagellum barely or just equal 



to breadth of head ; scape not quite reaching lower edge of median ocellus ; 

 hairs of flagellum very short and standing out only slightly. Head hardly 

 broader than the mesoscutum. Propodeum, in front of the costula, 

 for the most part distinctly sculptured . . H. elevatus (Walker) (p. 538) 



- Antenna with combined length of pedicellus and flagellum 1-25 to 1-3 times 



breadth of head ; scape reaching to, or slightly above, the lower edge of the 

 median ocellus ; hairs of flagellum longer, their length more than one third 

 the breadth of the segments and standing out at 30 to 40 . Head slightly 

 broader than the mesoscutum. Propodeum, in front of the costula, weakly 

 sculptured or almost smooth . . . . H. tnyopitae sp. n. (p. 540) 



40 (16) Antennae entirely citron-yellow, or with the flagellum orange-yellow ; legs, 



except the hind coxae and sometimes the mid and fore coxae, bright yellow 41 



- Antennal flagellum testaceous with darker incisures, or infuscate dorsally, 



or wholly brown to black ; scape often more or less infuscate ; femora often 

 more or less infuscate, sometimes also the tibiae ; usually all the coxae are 

 dark ............. 44 



41 (40) Gaster with a yellow spot or transverse band. Fore, and sometimes mid, 



coxae often partly or entirely yellow. Postmarginal vein often not longer 



than the marginal vein ......... 42 



- Gaster immaculate. All coxae black with a metallic tinge. Postmarginal 



vein at least slightly longer than the marginal vein .... 44 



42 (40) Fore wing with postmarginal vein longer than the marginal vein. All coxae 



black with a metallic tinge . . . . H. cioni Thomson (p. 526) 



- Fore wing with postmarginal vein not longer than the marginal vein. Fore, 



and even mid, coxae often more or less yellow ..... 43 



43 (42) Antenna with scape reaching above the vertex, nearly as long as an eye ; 



first funicular segment slightly to quite distinctly longer than the pedicellus, 

 sixth about 1-5 times as long as broad. Larger species, up to 2-7 mm. in 

 length ........ H. dispar (Curtis) (p. 532) 



- Antenna with scape barely reaching the vertex, much shorter than an eye ; 



first funicular segment not or only very slightly longer than the pedicellus, 

 sixth quadrate or only slightly longer than broad. Smaller species, at 

 most 2-3 mm. in length .... H. hieracii Thomson (p. 536) 



44 (41) Antenna with combined length of pedicellus and flagellum less than, or at most 



equal to, the breadth of the head ........ 45 



- Antenna with combined length of pedicellus and flagellum at least slightly 



greater than the breadth of the head ....... 50 



45 (44) Fore wing with postmarginal vein at least slightly longer than the marginal 



vein, the latter at most 1-25 times as long as, sometimes not longer than, 

 the stigmal vein. Antenna with hairs of flagellum most often subdecumbent 

 or standing out only slightly ........ 46 



- Fore wing with postmarginal vein not longer, sometimes slightly shorter, than 



the marginal vein, the latter sometimes more than 1-25 times as long as the 

 the stigmal vein. Antenna with hairs of flagellum often standing out at a 



