PROC. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



139 



Males 



1. Yellowish species sometimes more or less marked with brownish 



or blackish above 



Black pecies -5 



2. Third visible tergite (not counting the petiole) much the largest 



and extending far beyond the middle of abdomen. . . . 

 Fourth visible tergite (not counting the petiole) the largest, the 

 third never extending much beyond the middle of abdomen. 



3. Head, viewed from in front, forming a nearly equilateral triangle; 



malar space, in profile, nearly straight, as long as the eye and 

 without a carina separating face from cheeks; head, thorax, and 

 abdomen above dark brown; face, orbits, cheeks, three spots 

 above and sides of pronotum, spot on inner margin of para it- 

 sides, scutellum laterally and at apex, line on each lateral mar- 

 gin of propodeum, more or less of pleurae, and all legs, yellow- 

 ish white, hind tibia not black at apex pulchra Ashmead. 



Head not forming an equilateral triangle, malar space, in profile, 

 convex, shorter than the eye and with a distinct carinate line sepa- 

 rating the face from cheeks; color uniformly reddish testaceous, 

 the apex of hind tibia narrowly banded with black 



hcterogaster n. sp. 



4. Abdominal petiole fully twice as long as thick; third tergite very 



short, the fourth constituting distinctly more than half the 

 length of abdomen ; hind tibiae mostly blackish 



compressiventris n. sp. - 



Abdominal petiole scarcely longer than thick; apex of third tergite 

 at or very near the middle of abdomen; fourth tergite constitut- 

 ing not more than one-third the abdominal length and hardly 

 more than twice as long as the exposed part of the third; hind 

 tibiae entirely reddish testaceous mellea Ashmead 



5. Second visible tergite (not counting the petiole) occupying more 



than half the length of abdomen; tegulae black; scape and 



flagellum blackish piercei Crawford 



Second visible tergite (not counting the petiole) small, either the 

 third or fourth tergite the largest 6 



6. Third visible tergite much the largest tergite, extending far be- 



yond the middle of abdomen; the fourth tergite not much longer 

 than the first; fifth about two-thirds as long as tho fourth 



insularis Ashmead 



Third visible tergite not longer than the fourth and not extending 

 much beyond the middle of abdomen 7 



7. Third visible tergite very short, scarcely longer than the second 



and not extending beyond the basal one-third of the abdomen; 

 fourth tergite comprising about two-thirds of Ihe length of 

 abdomen and fully twice as long as the three first combined; 

 legs including all coxae pale testaceous pallid! /H-H Ashmead 



