294 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BulL 



Key to species. 



1. Scutel quadrangular, flat above and distinctly margined and 



beveled laterally seminiger 



Scutel triangular, not flat above, but subpyramidal 2 



2. Abdomen partly rufous; coxae and femora, except apex of lat- 



ter, reddish communis 



Abdomen black or blackish communis var. clypeatus 



T. seminiger Cresson. 



Female and male: length 6-8 mm.; head and thorax mostly 

 black; fore and mid legs mostly brownish stramineous, hind legs 

 mostly dusky or dark brown ; most of first, sixth, and seventh 

 (fifth sometimes) dorsal abdominal segments black; areolet pres- 

 ent, oval petiolate ; ovipositor slightly exserted. 



T. communis Cresson. 



Female and male : length 6-9 mm. ; head and thorax mostly 

 black; first dorsal abdominal segment with the basal half partly 

 black; legs mostly reddish; areolet present, quadrangular, its 

 sides subequal, nearly sessile; ovipositor distinctly exserted. 

 °T. communis var. clypeatus Provancher. 



Male: differs from the typical form in having the abdomen 

 black or blackish. 



Quadrigana Davis. 

 °Q. americana Cresson. 



Female and male: length 9-11 mm. ; black, with the abdomen, 

 except basal portion of petiole, reddish in the male; the face, 

 scape beneath, mouth-parts, tegulse, fore and mid legs, trochan- 

 ters, tarsi, and an annulus on the tibiae of the hind legs pale 

 yellow ; in the female these parts are more nearly reddish, while 

 the face above the clypeus is mostly black. 



Cosmoconus Foerster. 

 °C. canadensis Provancher. 



Female and male: length 6-9 mm. ; black; face, mouth- 

 parts, more or less of antennse at base, fore and mid legs, except 

 more or less of the femora and coxae, hind legs (except coxae, 

 femora and apex of tibiae), tegulae, and more or less of abdomen 

 from apex of first to apex of fifth dorsal segment, pale lemon- 

 yellow; the third segment always yellow; antennae brown, red- 

 dish at apex. 



