PTEROMALIDAE OF N.W. EUROPE 517 



13 (12) Fore wing with postmarginal vein slightly shorter than the marginal vein, the 



latter 1 -45 to 1 -6 times as long as the stigmal vein ; wing hyaline. Malar 

 space approximately 0-4 length of eye. (Czechoslovakia) H. sp. indet. G (p. 538) 

 Fore wing with postmarginal vein slightly longer than the marginal vein, the 

 latter 1 -3 to 1 -35 times as long as the stigmal vein ; wing sometimes slightly 

 infuscate. Malar space about 0-47 length of eye. (Britain) H. altus (Walker) (p. 537) 



14 (11) Fore wing (cf. Text-fig. 404) with parastigma notably thickened, nearly or 



quite as thick as the broadest part of the marginal vein ; the other veins 

 relatively thick ; marginal vein 1-65 to 1-75 times as long as the stigmal 

 vein. Base of mandible separated from gena by a nearly semicircular mem- 

 branous space. Antenna : combined length of pedicellus and flagellum 

 equal to, or hardly greater than, breadth of head H. crassinervis Thomson (p. 537) 

 Fore wing with parastigma not so obviously thickened ; marginal vein often 

 shorter relative to the stigmal vein. Base of mandible separated from gena 

 by only a narrow lunate space . . . . . . . . 15 



15 (14) Antenna with combined length of pedicellus and flagellum about 1-75 times 



breadth of head ; all funicular segments about 2-5 times as long as broad 



H. tereus (Walker) (p. 531) 

 Antenna with combined length of pedicellus and flagellum at most about 1-4 

 times breadth of head ; first funicular segment at most 2-3 times, sixth at 

 most barely twice, as long as broad . . . . . . . 16 



16 (15) Antennae, and legs, not counting coxae, entirely bright yellow to orange. 



Propodeum more than half as long as the scutellum ; its median area 

 uniformly or nearly uniformly reticulate, without a costula or with at most a 

 trace of one ........... 40 



- Antennae and legs never both entirely bright yellow or orange ; at least the 



flagellum, or the femora, more or less infuscate or brownish . . . 17 



17 (16) Propodeum with a distinct costula ; plicae posteriorly, at sides of nucha, con- 



verging only moderately strongly. Species parasitic on Diptera Trypetidae 23 



- Either the propodeum lacks a costula ; or else the plicae posteriorly con- 



verge strongly ........... 18 



18 (17) Propodeum distinctly less than half as long as the scutellum ; plicae pos- 



teriorly, at sides of nucha, converging strongly or moderately strongly, reach- 

 ing or nearly reaching the hind edge of the propodeum ; costula often 

 indicated ............ 20 



Propodeum from nearly half, to more than half, as long as the scutellum ; 

 plicae posteriorly usually converging less strongly, sometimes not nearly 

 reaching the hind edge of the propodeum ; costula rarely present . . 19 



19 (18) Propodeum with plicae posteriorly, at sides of nucha, converging strongly, 



reaching or virtually reaching the hind edge of the nucha ; the propodeum 

 is at most half as long as the scutellum, but usually slightly less than half 20 

 Propodeum with plicae posteriorly either subparallel or only converging 

 slightly ; or else not nearly reaching the hind edge of the nucha ; propodeum 

 at least slightly more than half as long as the scutellum .... 40 



20 (19) Propodeum with plicae sharp only posteriorly, absent or hardly traceable in 



the middle, though represented at the base of the propodeum by a pair of 

 foveae . . . H. ? ochrocerus Thomson (p. 526) 



Propodeum with plicae traceable from base to hind edge of propodeum, distinct, 



and sometimes sharp, throughout . . . . . . .21 



21 (20) Antennal scape as long or virtually as long as an eye. Species not parasitic 



on Diptera Trypetidae. .... H. semotus (Walker) (p. 529) 



- Antennal scape distinctly, sometimes much, shorter than an eye. Species (so 



far as known) parasitic on Diptera Trypetidae ..... 22 



