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U. S. NATIONAL MUSEUM BULLETIN 216 



often with a continuous band of hairs along its upper edge, the hairs 

 arising from very fine punctures, elsewhere the metapleurum polished, 

 below the middle with broad gentle rippling, over base of hind coxa 

 smooth and gently convex; median and sublateral longitudinal carinae 

 of third tergite nearly reaching apex of tergite; fourth tergite with 

 median and sublateral longitudinal carinae present basally. 



Two Nearctic and two unidentified Neotropic species of this group 

 are before us. The Neotropic species comprise one from Costa Rica 

 and another from Guatemala, British Guiana, and Argentina. The 

 two Nearctic species are treated below. 



18. Trieces calvatus, new species 



Figure 182,b 



Front wing 3.5 to 4.2 mm. long; face in profile weakly convex, its 

 punctures rather coarse and strong, their interspaces about 0.25 their 

 diameter; flagellum with about 29 segments in male, with about 24 

 segments in female; third segment of maxillary palpus about 3.0 as 

 long as wide; prepectal carina continuing dorsally till it reaches front 

 edge of mesopleurum ; lateral carina of scutellum not projecting beyond 

 apex of scutellum to form a tooth ; metapleurum with about six strong, 

 straight, sublongitudinal rugae, without hairs; front spur of middle 

 tibia about 0.42 as long as hind spur; second segment of middle tarsus 

 about 2.0 as long as wide in male, about 1.33 as long as wide in female; 

 median and sublateral longitudinal carinae of fourth tergite extending 

 about half the length of tergite; sublateral carina on third tergite 

 weakly curved. 



Black. Face, side of frons, clypeus, and mouth parts, yellow tinged 

 with fulvous; antenna fulvous brown, paler below and basally; tegula 

 fulvous, yellow at base; legs fulvous, the extreme apex of femora, basal 



Figures 34, 35.— Localities: 34 (left), Trieces calvatus; 35 (right), T. dentatus. 



