PTEROMALIDAE OF N.W. EUROPE 371 



- First funicular segment of antenna not constricted proximally, often rela- 



tively short ; clava often relatively longer. When the fore wing is 

 maculate, then the marking usually consists of a cloud around or below 

 the stigmal vein ; but if there is a single cloud below the marginal vein, 

 then the first funicular segment of the antenna is nearly always shorter 

 than the pedicellus .......... 103 



103 (102) Fore wing with infumate cloud, or fuscous markings .... 104 



Fore wing immaculate . . . . . . . . . .105 



104 (103) Fore wing with a fuscous cloud immediately beyond the speculum, this 



cloud usually extending to the marginal and stigmal veins and often forming 

 a transverse band ; pronotal collar rounded off in front ; first funicular seg- 

 ment of antennae as long as or slightly longer than the pedicellus, flagellum 

 stout and cylindrical, clava very short, only about 1-5 times as long as 

 broad ; stigmal vein (Text-fig. 309) forming an acute a"ngle with the 

 postmarginal vein. Antennae inserted hardly above level of ventral 

 edge of eyes ; scape almost as long as an eye, legs stout, especially femora 



ARTHROLYTUS Thomson (p. 789) 

 If the fore wing has a more or less developed cloud in this position, then 

 either (1) the pronotal collar is sharply margined anteriorly; or (2) the 

 first funicular segment of the antenna is very distinctly shorter than the 

 pedicellus ; or (3) the stigmal vein forms a less acute angle with the 

 postmarginal vein . . . . . . . . . .105 



105 (104) Antennal clava ventrally with a large area or band of micropilosity (Text- 



figs. 363, 365, 368, 430, 439) which extends at least half way to the base ; 

 sutures of clava in profile appearing oblique, or at least the second suture 106 

 Antennal clava with a small area of micropilosity which extends less than half 



way to the base ; sutures of clava not or hardly oblique . . 108 



106 (105) Propodeum with a large, strongly reticulate nucha, whose length is at least 



one third that of the propodeum. Pronotal collar usually weakly and 

 irregularly margined. Gaster ovate . SCEPTROTHELYS Graham (p. 482) 



- Propodeal nucha represented merely by a narrow, weakly aciculate transverse 



strip, or a ridge. Pronotal collar sharply margined. Gaster most often 

 long-ovate or lanceolate . . . . . . . . .107 



107 (106) Left mandible with three teeth, right mandible with four. Propodeum 



with a more or less distinct costula. Vertex without a transverse ridge 



APELIOMA Delucchi (p. 582) 

 Both mandibles with three teeth. Propodeum without a costula or with only 

 vague traces of one. Vertex often with a transverse ridge behind the ocelli 



HOLCAEUS Thomson (p. 584) 



108 (105) Mesopleura entirely reticulate ........ 109 



Mesepisternum with a partly to entirely smooth and polished triangular area 



below the base of the hind wing . . . . . . . .111 



109 (108) Propodeal plicae sharp only posteriorly, otherwise represented only by 



broad convex elevations ; median part of propodeum quite strongly 

 reticulate and relatively dull ; antennae inserted at least very slightly 

 above level of ventral edge of eyes . , . . . . .110 



Propodeal plicae complete, distinct to base of propodeum, usually sharp 

 throughout ; median area of propodeum usually more shiny and rela- 

 tively weakly sculptured, if not then antennae inserted level with ventral 



edge of eyes MESOPOLOBUS Westwood (p. 638) 



1 to (109) Thorax (Text-fig. 311) moderately arched dorsally, the scutellum in profile 

 distinctly convex ; mesoscutum convex, without visible piliferous punc- 



