189;").] NATURAL SCIENCES OF PHILADELPHIA. 267 



Yellowish spots on dorsal abdominal segments 3 and 4 distinctly 

 separated internally; clypeus about as broad as the three first 

 joints of antennae united are long, its anterior margin not 

 strongly incurved, subtruncate; lateral ridges of pygidial area 

 short, not twice as long as the latter is broad at apex . texanus. 



MALES. 



1 — Middle segment emarginate posteriorly at the sides; twelfth an- 

 tenual joint spinose beneath 2 



Middle segment not emarginate, the postero-lateral angles 

 rounded; twelfth antenual joint not spinose -5 



2 — Black, with paler markings . 3 



Yellow, with black markings 4 



3 — Seventh ventral segment slightly carinated down the middle; 

 space between eyes at base of clypeus distinctly less than the 

 combined length of joints 1 and 2 of flagellum; spine at apex 

 of eleventh antenual joint straight, rather short and indistinct; 



tibia? in part black Godmani. 



Seventh ventral segment flat, not carinated; space between the 

 eyes at base of clypeus about equal, or nearly so, to the com- 

 bined length of joints 1 and 2 of the flagellum; spine at apex 

 of eleventh antenual joint curved, long and prominent; tibiae 

 entirely yellow nanus. 



4 — Second submargiual cell distinctly petiolate flavus. 



Second submargiual cell not petiolate xanthochrous. 



5 — First and second transverso-cubital uervures widely separated 



above. Size large 6 



First and second transverso-cubital uervures narrowly separated 

 above or melting. Size medium; entirely deep black, the 

 second dorsal abdominal segment with a reddish fascia; wings 

 blue-black, the apical margin whitish unicinctus. 



6 — Yellowish spots on dorsal abdominal segments 3 and 4 extended, 

 so that they nearly meet internally; last dorsal segment 



rounded at apex brevipennis. 



Yellowish spots on dorsal abdominal' segments 3 and 4 widely 

 separated internally; last dorsal segment with a small, but dis- 

 tinct emargination at apex texanus. 



1. Stizus Godmani Cameron. 



Stizus Godmani Cam., Biol. Centr. Amer., Hym., PI. V, fig. 8, a. b. c, 9 $ ■ 

 Stiz?<s agilis Cam. (non S. agilis Sm.), ibid., p. 102. 



Mexico (Cameron) ; Lower California ; Santa Fe and Las Cruces, 



New Mexico (Cockerell); Colorado. 



2. Stizus nanus Hdl. 



Stizus nanus Handlirsch,Sitzb. Akad. Wissensch., Wien., LI, Bd., Abtli., I, p. 

 61, $ O. 



Georgia. 



