234 



U. S. NATIONAL MUSEUM BULLETIN 216 



PART 3 



Figures 117, 118. — Localities: 117 (left), Trachysphyrus ruralis; 118 (right), T. atritihialis. 

 26. Trachysphyrus mentigus, new species 



Front wing 5.6 to 10.3 mm. long; face 1.55 to 2.2 as wide as high 

 (somewhat narrower in most other Nearctic species, in the Albitarsis 

 group the face also unusually wide in erassulus and minimus) ; clypeus 

 transversely elliptic, in profile the basal half strongly convex and 

 the apical half approximately flat; temple about 1.0 as long as eye, 

 its front 0.55 weakly convex or ahnost flat, its hmd 0.45 strongly 

 convex; frons moderately concave, rather finely rugulose, the rugu- 

 losity irregular but largely transverse; mesopleurum of both sexes 

 reticulate rugulose, marginally smoother and with some distinct 

 punctation; propodeum rather evenly rounded, its basal carina 

 strong, at about its basal 0.33; apical carina of propodeum placed at 

 about the apical 0.33 of propodeum, strong sublaterally, forming a 

 broad, weak sublateral crest, its median 0.3 ± absent or weak; front 

 tibia not swollen, gradually narrowed to base; hind femur about 4.8 

 as long as deep in male, about 4.5 as long as deep in female; areolet 

 narrowl}^ pentagonal, its sides rather strongly convergent; second 

 recurrent vein moderately sinuate; first abdominal segment short 

 and stout; ovipositor sheath about 0.47 as long as front wing. 



There are three subspecies, as keyed and described below: 



1. Thorax ferruginous; range: Lassen Co., California. 



26b. mentigus rufator, new subspecies 

 Thorax black 2 



2. Hind femur black or black with a reddish brown tinge; range: Arizona. 



26a. mentigus mentigus, new subspecies 

 Hind femur ferruginous; range: Alaska to California and New Mexico. 



26c. mentigus rhodomerus, new subspecies 



26a. Trachysphyrus mentigus mentigus, new subspecies 



Male: Black. Facial orbit, narrow frontal orbit, very narrow 

 orbital stripe at top of eye and on temple, front edge of mandible, 



