PTEROMALIDAE OF N.W. EUROPE 117 



Gaster a little longer, 3-5 times as long as broad and about 1 3 times the length of head plus 

 thorax. The vertex, mesoscutum, axillae and scutellum are of a duller more bronze-green, 

 whilst the scape and pedicellus are slightly darker than in subglaber sp. n. 



The female differs from that of maculatus Erdos in the characters mentioned in my key to 

 species (q.v.). 



o*. Differs from the female in the structure of its antennae and gaster, also in its slightly 

 darker colour. The antennae are blackish with only the base of the scape narrowly pale ; 

 the trochanters and femora are brownish, the tibiae are brownish along their outer edge ; and 

 the tegulae are fuscous. 



The antenna (Text-fig. 83) is quite different from that of subglaber sp.n. in its broadened 

 scape and thicker flagellum with numerous sensilla and subadpressed hairs. 



Length of antennal scape about equal to the transverse diameter of an eye ; funicle rather 

 stout, distinctly broader than the pedicellus in profile, its segments relatively shorter, the 

 first hardly twice, the sixth hardly 1 -5 times, as long as broad ; clava slightly broader ; funi- 

 cular segments with numerous sensilla which are grouped in two rows upon each segment, the 

 clava also with numerous sensilla which are arranged in one row on each segment ; the hairs 

 of the flagellum are shorter than the breadth of the segments which bear them, and stand out 

 only very slightly. 



Holotype $. England : Norfolk, 17. vi. 1955, reared from logs of Alnus glutinosa 

 L. (G. H. Thompson), BM(NH). The holotype is labelled " Alnus glutinosa Cage 

 No.: 21 17 June 1955" ; "England G. H. Thompson. B.M. 1956-194" ; and 

 " Platygerrhus ductilis Walk. $ intermediate G. J. Kerrich det. 1955 " . 



Paratypes. 1 $, same data as holotype, i.vi.1955, BM(NH) ; Czechoslovakia : 

 Praha-okolf. Krc, 1 $, 22. vi. 1957, on Pinus (Boucek), in coll. Boucek. 



Biology. Unknown. 



The DUCTILIS-Grovv 



The species of this group have the propodeum weakly sculptured, and have the 

 callus and metapleuron differently coloured from the middle part of the propodeum. 

 Females have the funicular segments relatively longer, the malar space relatively 

 shorter, and the legs paler, than those of the dolosus-gvonp. The known males differ 

 from those of the dolosus-group in having the hairs of the antennal flagellum 

 subdecumbent. 



Platygerrhus ductilis (Walker) 



Trigonoderus ductilis Walker, 1836 : 17, o" ?• 



? Trigonoderus linearis Walker, 1836 : 19, $. 



Trigonoderus figuratus Walker, 1836 : 20, q*- 



? Trigonoderus deductor Walker, 1836 : 20, o*- 



? Trigonoderus Lappa Walker, 1848 : 128, 216, 6*- 



Platygerrhus ductilis (Walker) Kerrich & Graham, 1957 : 300-302, [ex parte]. 



Type material. Kerrich & Graham (1957 : 300) placed Trigonoderus affinis 

 Walker, T. amabilis Walker, and Platygerrhus gracilis Thomson, in synonymy with 

 ductilis. I now consider affinis to be a valid species, with amabilis and gracilis as 

 synonyms (see below) . 



