PTEROMALIDAE OF N.W. EUROPE 587 



minate ; last tergite varying from slightly longer than, to nearly twice its 

 basal breadth. Pronotum (Text-fig. 442) with sides of collar converging 

 forwards, not or hardly toothed anteriorly ; the transverse carina (" mar- 

 gin ") fine and only slightly raised, forming an even curve. ... 6 

 (5) Head (Text-fig. 440) more transverse (breadth to overall length 2-3 to 2-35) ; 



temples strongly narrowed and short . . breviusculus (Thomson) (p. 591) 



Head less transverse (breadth to overall length 2-1 to 2-15) ; temples less 



strongly narrowed ..... compressus (Walker) (p. 590) 



Key to Most European Species of 



Holcaeus Thomson and Cricellius Thomson 



(Males) 



Antennae with first funicular segment at least very slightly shorter than the 



second segment, the latter 1 -5 to 1 -8 times as long as broad ... 2 



Antennae with first funicular segment as long as, or usually slightly longer than, 



the second segment, the latter occasionally quadrate . • . . . 4 



(1) Vertex without, or with at most a very weak transverse ridge behind the 



ocelli. Pronotal collar having its anterior transverse carina only slightly 

 raised ............ 3 



Vertex with a distinct transverse ridge behind the ocelli. Pronotal collar hav- 

 ing its anterior transverse carina fairly strongly raised 



H. compressus (Walker) (p. 590) 



(2) Postmarginal vein of fore wing slightly shorter than, or at most as long as, 



the marginal vein. Head in dorsal view 1 -9 to 2 times as broad as long 



C. gracilentus (Boucek) (p. 593) 

 Postmarginal vein 11 to 1-2 times as long as the marginal vein. Head in 



dorsal view 2-05 to 2-1 times as broad as long . C. gracilis (Walker) (p. 592) 



(1) Combined length of pedicellus and flagellum only 1-2 to 1-3 times the breadth 

 of the head ; pedicellus as long as, or longer than, the first funicular seg- 

 ment ; all the funicular segments quadrate, or at most the proximal seg- 

 ments slightly longer than broad. Vertex without, or with at most a weak, 

 transverse ridge behind the ocelli. Anterior transverse carina of pronotal 

 collar not strongly raised ......... 5 



Either the combined length of the pedicellus and flagellum is 1 -5 to 1 -6 times 

 the breadth of the head ; or else the pedicellus is at least slightly shorter 

 than the first funicular segment, the latter 1 -5 to 3 times as long as broad. 

 Vertex often with a distinct transverse ridge behind the ocelli. Anterior 

 transverse carina of pronotal collar often strongly raised .... 6 



(4) Anterior margin of clypeus slightly curved forwards. Spur of mid tibia 



slightly more than half the length of the first tarsal segment. Antennal 

 flagellum as stout as, or even slightly stouter than, the pedicellus when the 

 latter is seen in dorsal view H. calligetus (Walker) (p. 588) 



Anterior margin of clypeus usually shallowly emarginate, rarely truncate. 

 Spur of mid tibia only about half the length of the first tarsal segment. 

 Antennal flagellum, proximally, usually slightly less stout than the pedicel- 

 lus when the latter is seen in dorsal view (dwarfs of gorgasus) ... 6 



(5) Combined length of pedicellus and flagellum only 1 -25 to 1-3 times the breadth 



of the head ; funicular segments relatively shorter, the first at most 1-5 

 times as long as the pedicellus and at most twice as long as broad, sixth 

 not or hardly longer than broad ; flagellum proximally usually as stout as 

 or a little stouter than the pedicellus in dorsal view. Vertex without, or 

 with at most a weak, transverse ridge behind the ocelli. Lateral front 



