AUT. liO WASPS OF SUBFAMILY PSENIXAE MALLOCH 29 



first segment, the latter more abruptly elevated in front than usual 

 (pi. 1, fig. 16) ; flagellum slightly clubbed, penultimate segment longer 



than thick arizonensis, new species 



At least a part of first tergite black or dark brown ; propodeum rarely as 

 finely sculptured, at least in enclosure ; first tergite not so abruptly 

 elevated in front 14 



14. Petiole of abdomen almost, or quite, as long as hind femur and not less 



than 1.5 as long as swollen part of first segment when viewed from 



above (pi. 1, fig. 17) ; propodeum rugoso-reticulate alongside enclosure. 15 



Petiole of abdomen shorter than hind femur and not noticeably longer than 



swollen part of first segment when viewed from above (pi. 1, fig. 18) 16 



15. Antennal fiagellura noticeably longer than head and thorax, not much 



swollen apically, penultimate segment distinctly longer than thick, with 

 a rather sharp linear elevation on one side of each segment from second 

 to fifth inclusive, which lies within margin of black part ; head behind 

 ocelli with microscopic transverse striae ; petiole narrowly slightly and 

 evenly convex on entire dorsal surface and without a sulcus close to 



each laterodorsal edge argentifrons (Cresson) 



Antennal flagellum shorter, more definitely swollen apically, penultimate 

 segment about as thick as long, with a broader and less evidently ele- 

 vated area on each segment from second to fourth, less obvious on fifth, 

 which is paler in color and lies on edge of yellow part ; head behind 

 ocelli without transverse striae ; petiole narrowly convex on middle 

 line and with a shallow piliferous sulcus along each laterodorsal 

 edge borealis (Smith) 



16. Propodeum finely sculptured, areas laterad of enclosure with numerous 



fine striae, enclosure finely inigoso-reticulate much as in arizonensis. 



gregarius Fox 



Propodeum coarsely rugoso-reticulate, areas laterad of enclosure with much 



coarser striae, sometimes reticulate almost up to edge of enclosure. 



pauper (Packard) 



17. Abdomen entirely without red basal markings, apices of some of tergites 



more or less evidently brownish yellow maculipes Fox 



Abdomen with at least a part of second tergite distinctly red on disk 18 



18. Abdomen with only petiole of first segment black, swollen part of tergite, 



and at least second and third tergites red 19 



Abdomen with petiole and at least a large part of swollen part of segment 

 black 22 



19. Propodeum with areas contiguous to enclosure broadly glossy and without 



a trace of sculpture politus, new species 



Propodeum always with more or less definite sculpture on areas laterad of 

 enclosure, .sometimes rather fine contiguous to it 20 



20. Propodeum finely longitudinally striate, enclosure a little more coarsely so 



than contiguous areas, latter in exceptional cases almost without striae 

 close to edges of enclosure and becoming progressively more evidently 

 striate toward lateral curves and over latter ; hind coxae with a distinct 

 fine carinate line on inner or opposed sides ; petiole of abdomen slender, 

 usually at least as long as hind femur, slightly widened at apex, where 

 it is about one sixth as wide as its length, convex and not sharply mar- 

 gined on each side above, the laterodorsal sulci practically lacking ; face 

 not wider at lower edge of the antennal insertions than long in center ; 

 petiole black to apex below cressoni (Packard) 



