100 HYMENOPTERA. 



10. Face marks similar to episcopalis, entire body coarsely punctured, 

 deep fossa on posterior face of propodeum...fossata, n. sp. 



Small, lateral face marks short and very broad, supra-clypeal area 

 very narrow, (fig. 107), abdomen punctured. .coloradeusis. 



Similar to coloradeusis , but lateral face marks not extending above 

 antennal sockets, supra-clypeal area not so narrow, (fig. 110) . 



calvus, n. sp. 



Lateral face marks narrow, tapering to a point not far above sock- 

 ets, supra-clypeal area not extremely narrow, abdomen punc- 

 tured. Western N. A ..wootoui. 



Face marks usually extending above antennal sockets, but not en- 

 larged above, abdomen impunctate or nearly so, scape stout 

 without yellow, (figs. 93-100) inodestus. 



K EY TO MALES.— Based on genital characters. 

 Eighth ventral plate without any distal pedicel.basalis and potens. 

 Eighth ventral plate with short, truncate distal pedicel, without apical 



lobes , hairless 1 . 



Eighth ventral plate with distal pedicel bearing apical lobes 2. 



1. Wing of seventh ventral plate broad, somewhat ovate, rather heavily 



haired, without basal tuft, (fig. 29) zizise. 



Wing of seventh ventral plate narrowed toward apex, with more or 

 less prominent lobe at base, (figs. 69-76). 



iiiodestns, episcopalis, fossata n. sp. 



2. Seventh ventral plate without tooth-like processes or flap, (fig. 60). 



cookii n. sp. 

 Seventh ventral plate with tooth-like processes and membranous 



flap 3. 



Seventh ventral plate without tooth-like processes, with hairless 



membranous flap 8, 



3. Apical pedicel of eighth ventral plate with dark, chitinous, more or 



less horn-like projections, (fig. 49) 4. 



Apical pedicel lacking these projections 5. 



4. Basal part of seventh ventral plate long and narrow, (fig. 44). 



conspicua. 

 Basal part not so narrowed, (fig. 37) rudbeckiae. 



5. Lobes of eighth ventral plate granulated, stout ; teeth of seventh 



ventral plate short, (figs. 52 and 38) cressoiii. 



Eighth ventral plate not granulated ; seventh ventral plate with 

 short wings, teeth long and narrow ; eighth ventral plate 

 long, (figs. 46 and 43) tridentulus. 



Similar to tridentulus, but small, eighth ventral plate short (Figs. 

 48 and 42) grossicornis. 



Apical lobes of eighth ventral plate broad, flat, with short spines; 

 base of wings of seventh ventral plate very long, (figs. 45 

 and 41) varifrons. 



