38 U. S. NATIONAL MUSEUM BULLETIN 216 



2. Trieces costatus (Davis) 



Figures 178,m; 180,b 



Chorinaeus costatus Davis, 1897, Trans. Amer. Ent. Soc, vol. 24, p. 211; d", ?. 



Lectotype: 9, New Hampshire (Philadelphia). 

 Chorinaeus -pusillus Davis, 1897, Trans. Amer. Ent. Soc, vol. 24, p. 211; d\ 



$ (new synonymy) . Lectotype: ?, Washington (Philadelphia). 



Front wing 4.0 to 4.9 mm. long; face about 1.3 as wide as high, 

 with moderate sized punctures that are separated by about 0.5 their 

 diameter; face and clypeus in profile moderately convex; attachment 

 of front tentorial arm making a long line dorsomesad from clypeal 

 fovea ; eye of male without hairs, of female with very short sparse hairs ; 

 mandible of female very slender, with few or no punctures distad of its 



Figure 17. — Localities for Tri- 

 eces costatus. 



basal 0.5, its upper tooth rather elongate and its lower tooth very 

 small (in other species of the genus, the mandible is stouter, punctate 

 to beyond its basal 0.5, and with the two teeth more nearly equal); 

 flagellum of male with about 36 segments, of female with about 32 

 segments; metapleurum with a broad band of hairs dorsally, which is 

 interrupted near its front end so that there is a small separate patch 

 of about 12 hairs in front upper corner of metapleurum; wrinkles of 

 metapleurum moderately coarse, extending forward nearly to middle of 

 metapleurum; propodeal spiracle elliptic, barely separated from pleural 

 carina; front spur of middle tibia about 0.50 as long as hind spur; 

 second segment of middle tarsus about 2.2 as long as wide in male, 

 about 1.8 as long as wide in female; second abdominal tergite about 

 0.85 as long as wide in male, about 0.80 as long as wide in female, 

 its punctures of moderate size, close, a little elongate; sublateral 

 longitudinal carina on third tergite extending 0.5 to 0.8 its length, 

 in some males present also on basal part of fourth tergite. 



Black. Face, often lower lateral corner of frons, clypeus, cheek, 

 mouth parts, base of tegula, apex of femora, and basal 0.2 of tibiae, 



