196 U. S. NATIONAL MUSEUM BULLETIN 216 



present; median longitudinal carina and apical transverse carina of 

 propodeum complete; second lateral area of propodeum with hairs 

 along its lateral edge and apicolaterally, or sometimes with hairs over 

 most of its surface except the mesobasal corner; nervulus distad of 

 basal vein by about 0.4 to 0.6 its length; front spur of middle tibia 

 about 0.45 to 0.60 as long as hind spur; second segment of middle 

 tarsus about 1.3 as long as wide; first tergite 1.7 to 2.3 as long as it is 

 wide at laterobasal corners; second tergite about 0.7 as long as wide, 

 with moderate-sized, rather sharp punctures the interspaces of which 

 are about 1.0 to 4.0 the diameter; epipleurum of third tergite wedge- 

 shaped, broadest posteriorly, its inner edge straight or weakly concave. 

 This group includes the three Nearctic species described below, 

 five unidentified Neotropic species, two unidentified species from 

 Japan and China, one unidentified species from Java, the European 

 Exochus flavomarginalis Holmgren, 1854, a Palaearctic species that is 

 commonly determined as E. prosopius Gravenhorst, 1829, and possibly 

 the Madagascan E. passaventi Seyrig, 1934. E. passaventi has the 

 interantennal process attenuate and the inner margin of the epipleurum 

 of the third tergite definitely concave, and is thus atypical for the 

 group. The species E. washingtonensis and E. flavomarginalis form a 

 subgroup with a short, rather pitlike notaulus, stouter, more depressed 

 build, and colorational divergences which indicate that they are 

 rather unrelated to the species close to "E. prosopius," and that they 

 are possibly closer to the Nearctic E. annulicrus and the European 

 E. semilividus Vollenhoven, 1875. These latter two, however, are 

 placed in the tibialis group because of the convex inner margin of the 

 epipleurum of the third tergite. 



11. Exochus lit us, new species 



Figures 179,h; 192,b 



Front wing 4.5 to 5.5 mm. long; body moderately slender; face 

 rather narrow, moderately protuberant, its punctures moderately 

 coarse, their interspaces about 0.7 their diameter; temple in profile 

 about 0.77 as long as eye in male, about 0.85 as long as eye in female; 

 notaulus a short sharp groove, deep anteriorly; front spur of middle 

 tibia about 0.55 as long as hind spur; front spur of hind tibia about 

 0.84 as long as depth of its tibia; hind femur about 2.55 as long as 

 deep; second lateral area of propodeum with hairs laterally and 

 apicolaterally. 



Black. Face of male, upper margin of face of female, small triangle 

 at top of eye, marks on cheek in male, clypeus of male, mandible, 

 glossa, small hind corner of pronotum, subtegular ridge, and vertical 

 elliptical area on prepectus of male, pale yellow. Usually the male 

 face has a median vertical blackish mark, and the male clypeus has 



