256 



U. S. NATIONAL MUSEUM BULLETIN 216 



apically above; hind tibia and tarsus whitish stramineous, the apical 

 0.28 of the tibia dark brown and apical half of fifth tarsal segment 

 brown. 



Type: cf, bred from Heterarthrus nemoratus, Jimpond, Maine, 

 June 2, 1937 (Washington, USNM 63676). 



49. Exochus pleuralis Cresson 



Figures 190,o; 196,c 



Exochus pleuralis Cresson, 1864, Proc. Ent. Soc. Philadelphia, vol. 3, p. 286; d*. 



Type: d\ Illinois (Philadelphia). 

 Exochus pallipes Cresson, 1864, Proc. Ent. Soc. Philadelphia, vol. 3, p. 287; d* 



(new synonymy). Type: d", Illinois (Philadelphia). 

 Exochus evectus Cresson, 1872, Trans Amer. Ent. Soc, vol. 4, p. 168; ? . Type: 



9 , Bosque Co., Tex. (Washington). 

 Exochus pallidipes Dalla Torre, 1901, Catalogus hymenopterorum, vol. 3, p. 213 



(emendation) . 



Front wing 3.2 to 4.5 mm. long; combined face and clypeus about 



1.03 as high as wide in male, about 0.97 as high as wide in female, 

 their convexity stronger in a vertical direction than horizontally, 

 especially in female; apical angle of interantennal process about 82 

 degrees; median area of frons rather strongly raised and differentiated; 

 median 0.5 of clypeal margin approximately straight; mandible of 

 moderate size, not twisted, tapered evenly but rather weakly from 

 its condyles to a moderately wide apex, its lower tooth small and 

 upper tooth large, its outer face rather convex and with a few small 

 punctures; second lateral area of propodeum with hairs apicolaterally ; 

 punctures of second abdominal tergite of moderate size and sharpness, 

 very sparse or absent medially, the sublateral ones separated by about 



1.4 their diameter; front spur of hind tibia about 2.7 as long as wide 

 in male, about 2.8 as long as wide in female; male clasper of moderate 

 size and hairiness, its apex rounded, a little oblique. 



Figure 155. — Localities foi 

 Exochus pleuralis. 



