PTEROMALIDAE OF N.W. EUROPE 113 



5 (4) Antenna with hairs of flagellum standing out strongly ; scape 3-5 to 3-7 times 



as long as broad, only slightly expanded above the middle, where its front 

 edge has a small boss which extends hardly half way down the scape. 

 Scutellum moderately convex .... tarrha (Walker) (p. 122) 



- Antenna (Text-fig. 82) with hairs of flagellum standing out only moderately ; 



scape 2-9 to 3-1 times as long as broad, more distinctly expanded above the 

 middle, its front edge with a larger boss. Scutellum weakly convex 



longigena sp. n. (p. 120) 



6 (1) Propodeum between the spiracles as strongly reticulate as the callus and 



metapleuron ; all these parts greenish or bluish. Gena, just behind the 

 malar sulcus, shiny and nearly smooth. Antennal scape (Text-fig. 83) 

 hardly expanded above the middle, the boss on its front edge very indistinct 

 and only slightly smoother than the rest of the scape . unicolor sp. n. (p. 116) 



- Propodeum between the spiracles less strongly reticulate than the callus and 



metapleuron ; the former area green to blue, the latter areas normally 

 bronze to coppery. Gena usually reticulate or alutaceous all over, some- 

 times narrowly shiny along the malar sulcus. Antennal scape with a 

 distinct shiny boss on its front edge ....... 7 



7 (6) Antenna with first funicular segment 1-5 to i-8 times as long as broad, 1-3 to 



1 -8 times as long as the pedicellus ; flagellum appearing rather rougher 

 than in the following species. Legs relatively dark : normally all the 

 femora are mainly fuscous to black, the hind ones often wholly so ; tibiae 

 (at least the hind ones) usually infuscate medially ; sometimes the legs are 

 mainly blackish. Length 1-7 to 2-7 mm. 



Head shaped as in ductilis. Basal cell of fore wing usually with only one 

 row of hairs below the submarginal vein, sometimes two. Eye 2-3 to 27 

 times the malar space .... Pductilis f. linearis (Walker) (p. 118) 



- Antenna (Text-fig. 85) with first funicular segment 2 to 2-5 times as long as 



broad, i-8 to 2-6 times as long as the pedicellus ; flagellum appearing 

 relatively smooth. Legs relatively paler ; mid femora often testaceous, 

 sometimes also the fore femora ; tibiae most often testaceous, sometimes 

 the hind ones infuscate. Length 2-5 to 4 mm. ..... 8 



8 (7) Head in dorsal view 2-15 to 2-25 times as broad as long. Fore wing with basal 



cell usually with two or even three rows of hairs below the submarginal vein, 

 rarely only one row in small specimens ; stigma tending to be subcircular, 

 its lower edge evenly curved. Eye 2-25 to 2-5 times as long as the malar 

 space ........ ductilis (Walker) (p. 117) 



- Head in dorsal view 2-35 to 2-4 times as broad as long. Fore wing with basal 



cell usually with only one row of hairs below the submarginal vein, some- 

 times two rows ; stigma tending to be longer than high, its lower edge often 

 straight in the middle. Eye 2-7 to 2-9 times as long as the malar space 



affinis (Walker) (p. 118) 



The MACULATUS-Grovp 



The three forms included here are characterized by their very strongly and 

 coarsely reticulate propodeum, and by the similar colour of the propodeum and 

 metapleuron (see key to species). At first I believed that all three forms might 

 belong to one variable species ; but the discovery of three male forms having different 

 antennae negatived this view. The differences between the respective females are 

 small, but this seems to be the rule in Platygerrhus ; however, they work out consist- 

 ently in the material studied. It will be interesting to see whether they prove to 



