518 M. W. R. de V. GRAHAM 



22 (21) Pronotal collar, medially, about one quarter as long as the mesoscutum. 



(Madeira) H. integer (Walker) (p. 538) 



- Pronotal collar, medially, at most slightly more than one fifth as long as the 



mesoscutum. European species ....... 23 



23 (22) Antennal flagellum very slender, not or hardly stouter than the pedicellus 



when the latter is seen in dorsal view ; funicular segments long, the first 

 2 to 2-25 times, the sixth i-6 to 1-7 times, as long as broad. Propodeum 

 slightly more than half as long as the scutellum. Antennal scape reaching 

 a little above the vertex. Gaster immaculate . . H. parietinae sp. n. (p. 553) 



- Antennal flagellum at least somewhat stouter than the pedicellus in dorsal 



view ; funicular segments rarely so long. Propodeum rarely more than 

 half as long as the scutellum ; if so, then the scape does not reach the 

 vertex, and the gaster has a yellowish spot ...... 24 



24 (23) Combined length of pedicellus and flagellum about 1 -3 times breadth of head ; 



funicular segments long, the first i-6 to i-8 times as long as the pedicellus, 

 sixth distinctly, usually about 1-5 times, longer than broad. Gaster either 

 with a pale dorsal spot, or with the ventral plica pale medially. Row of hairs 

 on lower surface of costal cell of fore wing complete . H. sp. indet. (p. 542) 



- Either combined length of pedicellus and flagellum not or hardly greater than 



breadth of head, and funicular segments relatively shorter ; or gaster 

 including the ventral plica immaculate ...... 25 



25 (24) Gaster with at least a small pale dorsal spot, or with the ventral plica pale in 



the middle. Head and thorax usually bright green to blue-green, occasion- 

 ally bronze-green .......... 26 



- Gaster, including its ventral plica, immaculate . . . . . . 27 



26 (25) Fore wing with postmarginal vein fully as long as, or slightly longer than, the 



marginal vein. Pronotal collar, medially, slightly more than one fifth as 



long as the mesoscutum . . . H. ? intermedins (Walker) (p. 542) 



- Fore wing with postmarginal vein slightly shorter than the marginal vein. 



Pronotal collar, medially, from slightly more than one sixth, to one fifth, 



as long as the mesoscutum . . . . H. patro (Walker) (p. 547) 



27 (25) Antenna with combined length of pedicellus and flagellum about 1 -3 times the 



breadth of the head .......... 28 



- Combined length of pedicellus and flagellum not or hardly greater than the 



breadth of the head .......... 29 



28 (27) Fore wing with row of hairs on lower surface of costal cell widely interrupted 



in the middle. Antenna with scape reaching the vertex ; funicular seg- 

 ments relatively long, the first 17 to 2 times, the sixth about 1-5 times, as 

 long as broad ....... H. tripolii sp. n. (p. 551) 



- Row of hairs on lower surface of costal cell complete. Antenna with scape 



reaching at most to level of middle of median ocellus ; funicular segments 

 often relatively shorter . . . . . . . . -39 



29 (27) Fore wing with row of hairs on lower surface of costal cell interrupted medially, 



sometimes widely so .......... 30 



- Fore wing with row of hairs on lower surface of costal cell complete . . 32 



30 (29) Head in dorsal view (Text-figs. 417, 418) with temples half or even slightly 



more than half as long as the eyes, converging only slightly ; frons pro- 

 jecting somewhat, the antennal toruli visible from above ; occiput deeply 

 excavated. Antennal scape reaching the vertex . . . . . 31 



- Head in dorsal view with temples relatively shorter, converging more strongly, 



more rounded ; frons not projecting medially, toruli hardly visible from 

 above ; occiput less deeply excavated. Antennal scape hardly reaching 

 the vertex ............ 33 



