168 U. S. NATIONAL MUSEUM BULLETIN 209 



3. Sixth sternite with a median longitudinal low polished ridge ; pronotum elongate; 



brush on inner side of hind tibia with a subapical interruption; a species 



with black body and red abdomen Nemagenia (p. 174) 



Sixth sternite with a median, apical, weakly raised, rounded ridge, the sternite 

 impressed on each side of the ridge; brush on inner side of hind tibia without 

 a subapical interruption except in the accepta group of the subgenus Age- 

 niella; coloration various 4 



4. Hind, middle, and front tibial spurs white or whitish (in A. arizonica the 



spurs are extensively infuscate but the whitish color still evident). 



Priophanes (p. 176) 



Hind tibial spurs fuscous; middle and front tibial spurs either white or 



fuscous Ageniella (p. 189) 



FEMALES 



1. Propodeum with long sparse erect hairs in addition to the short pubescence; 



third cubital cell receiving the second recurrent vein near its basal 0.35; 

 bristles on hind tibia long and stout, the tibia sometimes subserrate ex- 

 ternally Ameragenia (p. 215) 



Propodeum without long sparse erect hairs or with only a few such hairs; 

 third cubital cell receiving the second recurrent vein near or beyond its 

 middle (pi. 2, figs. 31, 32, 33, 34); bristles on hind tibia weaker 2 



2. Outer edge of hind tibia smooth Ageniella (p. 189) 



Outer edge of hind tibia with one or two longitudinal rows of teeth 3 



3. Brush on inner side of hind tibia with a subapical interruption; pronotum 



somewhat elongate Nemagenia (p. 174) 



Brush on inner side of hind tibia continuous to the apex 4 



4. Teeth on outer edge of hind tibia weak, the tibia longitudinally concave be- 



tween the dorsal and the very weak subdorsal rows of teeth; lower edge of 

 mandible in its basal third somewhat rounded and without a distinct ridge; 

 apical hairless margin of clypeus narrow, mat to polished. 



Leucophrus (p. 168) 



Teeth on outer edge of hind tibia rather strong, the tibia not longitudinally 



concave between the two rows of teeth; lower edge of mandible in its basal 



third accentuated by a longitudinal ridge; apical hairless margin of clypeus 



moderately wide, largely or entirely mat Priophanes (p 176) 



Subgenus Leucophrus Townes 



Leucophrus Townes, 1951, U. S. Dep. Agr., Agr. Monogr. No. 2, p. 917. Type: 

 Priocnemis semitincta Banks; original designation. 



Clypeus rather short, its hairless apical margin narrow, mat to 

 polished, and not set off by a groove; lower edge of mandible in its 

 basal third somewhat rounded and without a distinct ridge (with a 

 more or less distinct ridge in all the other subgenera except Nema- 

 genia) ; mesopleuron without an oblique carina at the front end of its 

 transverse suture; propodeum with a few erect hairs of moderate 

 length; brush on inner side of hind tibia continuous to the apex; hind 

 tibia of female with a dorsal row of weak longitudinal teeth and a sub- 

 dorsal row of subobsolete tuberclelike teeth, between the two rows 



