PTEROMALIDAE OF N.W. EUROPE 445 



It is doubtful whether Homoporus Thomson or Phanacra Forster (both published 

 in the same year) has priority. I follow the lead of Delucchi who adopted (1957a : 

 400-401) the name Homoporus in his revision of the European species. Paraptero- 

 malus Ashmead was synonymized with Merisus (sensu Gahan, 1933, nee Walker) 

 by Peck (in Muesebeck et al., 1951 : 547), but as Merisus in the sense of American 

 authors is the same as Homoporus Thomson, Parapteromalus Ashmead now becomes 

 a synonym of the latter. The genera Merisoporus Masi and Pseudomerisus Erdos 

 & Novitzky were united with Homoporus by Delucchi (1957a). The revision of 

 Homoporus by Szel^nyi (1956) contains some useful information but that author 

 was at a disadvantage because he had not seen the types of most of the species with 

 which he dealt. Delucchi's (1957a) revision is a very useful contribution and has 

 cleared up many problems ; it does not, however, take Szelenyi's work into 

 consideration. Delucchi's key to the species, which is on the whole very good, 

 will not work satisfactorily for some species, especially for British material, because 

 the colour of the coxae and femora is too variable. Some changes in nomenclature 

 have also occurred since the publication of his paper. The key to species presented 

 here deals mainly with the north-west European species ; I have not seen the types 

 of several of those described from Central Europe, which still need further revision. 



The form of the antennal clava is a useful character in 9 Homoporus. In some 

 species it is merely conically pointed apically ; in others it is acuminate and ends 

 in a very narrow " terminal stylus " which apparently represents the third claval 

 segment. 



Key to British (and some other European) Species 

 (Females) 



1 Pronotum as wide as the mesoscutum. Gaster fulvous, except sometimes at 



the base. Basal cell of fore wing with hairs scattered over its distal third to 



half. Head and thorax with conspicuous whitish hairs. 



Squat species ; thorax only about 1 -4 times, gaster about 1 -3 times, as 

 long as broad. Legs, except coxae, fulvous. First funicular segment 

 about half as long as pedicellus, subquadrate, fifth and sixth distinctly 

 transverse ...... semiluteus (Walker) (p. 458) 



- Either the pronotum is distinctly less wide than the mesoscutum ; or the 



gaster is wholly black with a metallic tinge. Basal cell of fore wing, not 

 counting any hairs which may be on the basal vein, usually bare, rarely with 

 a few hairs. Hairs of head and thorax rarely at all conspicuously whitish . 2 



2 (1) Antennae with third segment of flagellum anelliform, at most half as long as the 



fourth segment, without sensilla, quadrate to distinctly transverse . . 3 



Antennae with third segment of flagellum not anelliform, usually as long as or 

 longer than the fourth segment, provided with sensilla ; sometimes somewhat 

 shorter than the fourth, but then quadrate to slightly longer than broad . 4 



3 (2) Gaster black with metallic tints . . . . . . . . 13 



- Gaster at least partly yellowish, some specimens of fulviventris . . . 12 



4 (2) Fore wing with postmarginal vein longer than the marginal vein, the latter 



slightly to quite conspicuously thickened, five to nine times as long as its 

 breadth in the middle. Pronotum as wide as the mesoscutum. Both 

 mandibles with three teeth. Scutellum discally with coarse reticulation, 

 almost or quite as coarse as that of the posterior part of the mesoscutum . 5 



