5 o2 M. W. R. de V. GRAHAM 



broad ; last tergite rarely more than 1-2 times as long as its basal breadth. 

 Head and thorax often dull or bronze-green . H. intermedins (Walker) (p. 542) 

 Head in dorsal view (Text-fig. 410) twice or hardly more than twice as broad 

 as long ; temples nearly half as long as eyes, converging only very slightly. 

 Gaster 1-25 to 1-35 times as long as head plus thorax, 2-3 to 2-65 times as 

 long as broad ; last tergite 1 -3 to 1 -6 times as long as its basal breadth. 

 Head and thorax bright green ... H. temporalis sp. n. (p. 547) 



21 (19) Malar space nearly two thirds the length of an eye. Head and thorax olive- 



green with bronze reflections. Gaster hardly three times as long as broad, 

 only slightly longer than head plus thorax. Antennae with proximal seg- 

 ments of funicle subquadrate, distal segments slightly transverse. (Madeira) 



H. alternipes (Walker) (p. 543) 



- Malar space rarely more than slightly over half the length of an eye ; if nearly 



two thirds, then the head and thorax are bright green to blue, and the gaster 

 is longer, distinctly longer than head plus thorax, and three to four times as 

 long as broad (European species) . . . . . . . . 22 



22 (21) Smaller (i-8 to 2-5 mm.). Antennae with proximal segments of funicle 



quadrate, the first segment at least very slightly shorter than the pedicellus ; 

 sensilla in one, sometimes irregular, row on all the funicular segments . 23 



- Larger (2-5 to 4 mm.). Antennae with proximal segments of funicle at least 



very slightly longer than broad, the first segment as long as or longer than 

 the pedicellus ; sensilla in two rows on at least some of the funicular 

 segments ............ 24 



23 (22) Gaster 1-65 to 2-1 times as long as broad. Antennal flagellum testaceous 



beneath. Fore wing with marginal vein 1-27 to 1-45 times as long as the 

 stigmal vein. Head in dorsal view with temples hardly more than one 

 quarter as long as eyes . . . . . H . decipiens sp. n. (p. 548) 



- Gaster 2-2 to 3 times as long as broad. Antennal flagellum usually black, 



occasionally slightly testaceous beneath. Fore wing with marginal vein 

 1-35 to i-6 times as long as the stigmal vein. Head in dorsal view with 

 temples from nearly, to slightly more than, one third as long as eyes (Text- 

 fig. 406) ....... H. albipennis (Walker) (p. 544) 



24 (22) Marginal vein of fore wing 1-65 to 1-9 times as long as the stigmal vein. 



Gaster 1-3 to 1-5 times as long as head plus thorax, 3-4 to 4 times as long as 

 broad. Malar space from somewhat more than half, to nearly two thirds, 

 the length of an eye. Veins of fore wing fulvous or testaceous. Length of 

 body 4 to 4-8 mm. 



Gaster of male without a pale spot . . . H. caudiger sp. n. (p. 548) 



- Marginal vein 1-35 to 1-65 times as long as the stigmal vein. Gaster 1 -i to 1-3 



times as long as head plus thorax, 2-2 to 3-5 times as long as broad. Malar 

 space from hardly half, to somewhat more than half, the length of an eye. 

 Veins of fore wing often pale yellowish ....... 25 



25 (24) Gaster 2-2 to 3 times as long as broad, i-i to 1-3 times as long as head plus 



thorax. Marginal vein 1-35 to i-6 times as long as the stigmal vein. 



Gaster of male without a pale spot . . H. albipennis (Walker) (p. 544) 



- Gaster 3 to 3-5 times as long as broad, 1-25 to 1-3 times as long as head plus 



thorax. Marginal vein 1-5 to 1-65 times as long as the stigmal vein. 



Gaster of male with a yellowish subbasal spot . H. patro (Walker) (p. 547) 



26 (16) Antenna with combined length of pedicellus and flagellum fully equal to, or 



slightly greater than, the breadth of the head ; all funicular segments 

 longer than broad, or at most the sixth quadrate ; scape reaching middle of 

 median ocellus, or nearly to level of vertex. Gaster from nearly as long as, 



