612 M. W. R. de V. GRAHAM 



Key to European Species 

 (Females) 



i Anterior margin of clypeus (Text-fig. 469) with a small median tubercle or 



tooth. Postmarginal vein of fore wing obviously shorter than the marginal 

 vein. Spur of mid tibia half as long as the first tarsal segment. Antenna 

 (Text-fig. 501) inserted distinctly above ventral edge of eyes ; scape hardly 

 reaching the median ocellus ; clava, viewed in profile, symmetrical, the 

 lines separating its segments not oblique . . fortnosus (Walker) (p. 619) 



- Anterior margin of clypeus (Text-figs. 495, 496) shallowly emarginate or sub- 



truncate medially, without any tubercle or tooth. Postmarginal vein of 

 fore wing usually about as long as the marginal vein, though slightly shorter 

 in two or three species. Spur of mid tibia sometimes less than half as long 

 as the first tarsal segment. Antennal scape reaching at least to the level 

 of the median ocellus, except, in Ch. breviscapus, in which the antennae are 

 inserted practically level with the ventral edge of the eyes and the clava in 

 profile is asymmetrical ......... 2 



2 (1) Antenna (Text-fig. 502) with scape short, not nearly reaching the level of the 



median ocellus ; antennae inserted relatively low on the face, the lower 

 edge of their toruli being hardly above the ventral edge of the eyes. Size 

 and build much as in Ch. pulchripes ; combined length of pedicellus and 

 flagellum clearly less than breadth of head, anelli relatively large, clava 

 asymmetrical ; fore wing (Text-fig. 507) with veins rather thick, basal vein 

 thickly pilose, usually two, three or even four irregular rows of hairs on the 

 vein ; gaster with posterior half of basal tergite nearly always alutaceous, 

 remaining tergites entirely or almost entirely so breviscapus Graham (p. 624) 

 Antennal scape reaching at least the level of the lower edge of the median ocel- 

 lus ; antennae inserted distinctly above the ventral edge of the eyes. Species 

 sometimes slender with an elongate gaster ; combined length of pedicellus 

 and flagellum often equal to or slightly greater than breadth of head ; anelli 

 less conspicuous ; clava sometimes symmetrical ; fore wing with veins less 

 thick, basal vein with at most one complete row of hairs, sometimes bare ; 

 gaster with basal tergite usually smooth, sometimes weakly alutaceous along 

 its hind margin, the three following tergites with a broad strip, behind the 

 row of hairs, which is nearly smooth and more shiny than the rest . . 3 



3 (2) Antennae (Text-fig. 503) inserted far above the ventral edge of the eyes, the 



lower edge of their toruli is situated exactly half way between the anterior 

 margin of the clypeus and the front edge of the median ocellus ; scape 

 reaching well above the median ocellus and usually slightly above the 

 vertex ; funicle very slender, filiform ; clava, viewed in profile, symmetrical, 

 the lines separating its segments not oblique longiscapus Graham (p. 619) 



- Antennae inserted less far above ventral edge of eyes, the lower edge of their 



toruli situated distinctly nearer to the anterior margin of the clypeus than 

 to the front edge of the median ocellus ; scape rarely reaching above the 

 top of this ocellus, or if so (phalaridis, Text-fig. 498) then the funicle is stouter 

 and the clava, viewed in profile, is asymmetrical, the lines separating its 

 segments slightly oblique ......... 4 



4 (3) Gaster (Text-fig. 494) lanceolate, four to five times as long as broad and nearly 



or quite 1 -5 times the length of head plus thorax ; last tergite 1 -7 to 2 times 

 as long as its basal breadth. Propodeum much as in Text-fig. 492, about 

 one third or slightly less than one third as long as the scutellum ; its 

 median area hardly produced beyond the level of the hind edges of the 

 supracoxal flanges (which are only slightly curved), weakly sculptured, 



