746 M. W. R. de V. GRAHAM 



rather deeply excavated. Propodeum about two thirds as long as the 

 scutellum, its median area 1-2-1-4 times as broad as long 



submarginatus (Thomson) (p. 756) 

 Antenna (Text-fig. 634) with scape nearly reaching the level of the vertex. 

 Head in dorsal view (Text-fig. 622) with scrobes less deeply excavated. 

 Propodeum three quarters as long as the scutellum or rather more, its 

 median area 1-1-1-2 times as broad as long . . potatoriae sp. n. (p. 758) 



27 (23) Gaster lanceolate-ovate, 1-8-2 times as long as broad, distinctly longer than 



the thorax. Larger species, length 2-3-3-3 mm. Left mandible with 3 

 teeth, right mandible with 4 ........ 28 



Gaster ovate, 1-3-1-65 times as long as broad, about as long as the thorax. 



Smaller species, length 1-7-2-5 mm. ....... 29 



28 (27) Head in dorsal view very like that of submarginatus (Text-fig. 621) with the 



temples slightly more than one third as long as eyes. Antenna (Text-fig. 

 636) with scape not reaching the vertex . . germanicus sp. n. (p. 761) 



Head in dorsal view (Text-fig. 624) with temples at most one third as long as 

 eyes. Antenna with scape reaching or virtually reaching the vertex 



acuminatus sp. n. (p. 762) 



29 (27) Head in dorsal view (Text-figs. 621-623, 625) with temples one third or more 



than one third as long as eyes. Gaster at most i-6 times as long as broad. 

 Both mandibles with 4 teeth [mandibular formula of dubius unknown] . 30 



Head in dorsal view (Text-fig. 626) with temples one quarter as long as eyes 

 or even less. Gaster sometimes relatively longer than in the above. Left 

 mandible often with 3 teeth ......... 34 



30 (29) North American species with scutellum flattened. Antenna (Text-fig. 640). 



Propodeum with a distinct, sharp median carina. Head, Text-fig. 623 



dubius (Ashmead) (p. 776) 

 European species with scutellum moderately convex ..... 31 



31 (30) Antennal scape barely reaching the lower edge of the median ocellus. Head 



in dorsal view (Text-fig. 621) with scrobes deeply excavated, temples 

 slightly angulate posteriorly. Median carina of propodeum distinct 



submarginatus (Thomson) (p. 756) 

 Antennal scape reaching nearly or quite to the level of the vertex. Head in 

 dorsal view (Text-figs. 622, 625) with scrobes less deeply excavated ; 

 temples sometimes rounded posteriorly ....... 32 



32 (31) Antenna (Text-fig. 634) with all funicular segments slightly transverse. 



Head in dorsal view (Text-fig. 622) with temples somewhat rounded 

 posteriorly ........ potatoriae sp. n. (p. 758) 



Antenna with proximal segments of funicle not transverse. 33 



33 (32) Head in dorsal view (Text-fig. 625) with temples rounded posteriorly. 



Median carina of propodeum distinct . . . lasiocampae sp. n. (p. 759) 



Head in dorsal view with temples slightly angulate posteriorly, much as in 

 submarginatus, Text-fig. 621. Median carina of propodeum vague or 

 absent ......... sp. indet. A (p. 756) 



34 (29) Head in dorsal view (Text-figs. 624, 626) with temples relatively straight ; 



head 203-2-15 times as broad as long. Gaster 1-7-2 times as long as 

 broad, at least somewhat longer than the thorax. Length 1-8-3-3 mm. 35 



Head in dorsal view (Text-figs. 613, 628) with temples rounded ; head 1-9-2 

 times as broad as long. Gaster sometimes relatively shorter. Length 

 1-3-2-3 mm. ........... 36 



35 (34) Head (Text-fig. 624) 1-2-1-3 times as broad as the mesoscutum. Marginal 



vein 1-55-1-75 times as long as the stigmal vein. Gaster slightly acuminate 

 apically ; last tergite as long as, or slightly longer than, its basal breadth ; 



