WILLIAM J. FOX. 15 



21. I*!«eii uniciiivtiis Cress. 



Mimesa uiiicincta Cresson, Proc. Ent. Soc. Phil, iv, 488. % (non 9 )- 1865. 



9- — Head finely and closely punctured ; face silvery, the clypeus nude, except 

 laterally, distinctly punctured, its fore margin broadly truncate ; space between 

 hind ocelli less than that between them and eyes ; antenrite shorter than the head 

 and that portion of thorax anterior to middle segment; dorsulum with subtile 

 punctures; mesopleurte distinctly striated above and on apical portion; rugae of 

 enclosure of middle segment oblique, transverse apically; posterior face sulcate 

 down middle, finely rugose, not at all reticulate; sides finely punctured : abdomen 

 with apex of first, the second entirely and most of third segment, reddish : petiole 

 longer than in pauper, but still shorter than hind femur, rounded, indistinctly 

 sulcate near each side, on the sides not sulcate ; second submarginal cell narrowed 

 more than one-half above. Length 6-7 mm. 



%. — Face and clypeus silvery, the fore margin suberaarginate medially; an- 

 tennte fully as long as head and thorax, elongato-clavate, basal joints of flagellum 

 indistinctly prominent beneath ; rugae of enclosure of middle segment close, no 

 transverse ones apically, or if present they are indistinct; posterior surface strongly 

 rugose, but not distinctly reticulate; legs black, tarsi testaceous; abdomen with 

 apex of first and second segments entirely, red ; petiole but little shorter than 

 hind femur, second submarginal cell narrowed barely one-half above. Length 

 5.5 mm. 



Colorado. The petiole is longer than in pauper, and sculpture 

 of middle segment finer. The S differs from confertus by finer punc- 

 tuation of head, etc. 



Cresson's type of this species is a male and not a female, as de- 

 scribed by him. 



22. Psen clypeatus n. sp. 



9. — Face and clypeus densely silvery; clypeus with four distinct teeth on 

 anterior margin, the median two by far the larger, and are rather acute and dis- 

 tinctly separated ; antennte longer than the head and that portion of thorax 

 anterior to middle segment, but shorter than head and thorax ; dorsulum striato- 

 punctate, distinctly striated posteriorly ; mesopleurje finely punctured ; enclosure 

 of middle segment large, with a large, central, smooth area, on each side of which 

 the rugffi are widely separated, several transverse rugse at apex ; posterior 

 surface rugoso-reticulate, depressed medially ; sides finely rugose : abdomen with 

 apex of first segment and second entirely, reddish ; petiole robust, shorter than 

 hind femur, deeply trisulcate above, on the sides bisulcate. Length 6 nun. 



■^ .—The male agrees with the female in most points; only the median teeth 

 of clypeus distinct, and they are closer together and much less evident than in 

 9 ; anteunse longer than head and thorax, not pale beneath, joints of flagellum 

 rather irregular ; tarsi pale ; petiole almost as long as hind femora. Length 5.5 mm. 



Nevada; Colorado (Gillette). Two specimens. In its deeply 

 trisulcate petiole this species approaches those of Group niger, but 

 the pygidium of female is broad and flat. It differs from all its 

 immediate relatives by the striated dorsulum and form of petiole. 



23. Psen granulosus n. sp. 



'J,.— Head rather strongly punctured; face and clypeus silvery, the latter bi- 

 dentate medially ; space between hind ocelli slightly greater tiian that between 



TKANS. AM. ENT. SOC. XXV. J.\NUARY, 1898. 



