1962] 
Brown — Striunigenys 
259 
anterior peduncle; gastric hairs mostly stiff, remiform (i.e., with 
broadened apices) (Fig. 5); head broader (Cl > 79; Fig. 1) 
(Nicaragua to s. Mexico) ludia Mann 
Petiolar node with a steep anterior face, set off from its anterior 
peduncle; gastric hairs long, finely flagelliform (Fig. 6) ; head 
narrower (Cl < 78; Fig. 2) lacacoca; go to 2 1 
12. Large hairs of gastric dorsum remiform (i.e., oar- or paddle- 
shaped at apex) ; smaller species 13- 
Large hairs of gastric dorsum fine, long, flagelliform 15. 
13. First gastirc tergite reticulate-punctulate and opaque; preapical 
armament of mandible reduced to a single minute denticle situ- 
ated somewhat distal to the midlength of the inner border, but 
remote from the apex (Fig. 12) (s. Mexico) boneti Brown 
First gastric tergite smooth and shining beyond the basal belt of 
longitudinal costulae ; preapical armament of mandible consisting 
of a distinct tooth, with or without an additional minute denticle 
near mandibular midlength 14. 
14. Dorsal borders of antennal serobes broad, lamellose; preapical 
armament of mandible consisting of a single strong tooth (n. 
Argentina) ogloblini Santschi 
Dorsal scrobe borders merely narrowly cariniform; preapical 
mandibular armament consisting of a tooth near the apex plus 
an additional minute denticle near the midlength (n. Argentina 
to s. Brazil; also Cuba and Louisiana, where probably intro- 
duced) silvestrii Emery 
15. Ventral ends of propodeal lamellae at most rounded or bluntly 
angulate, not dentiform 16. 
Propodeal teeth large and acute, matched on each side below by 
a (metasternal) tooth of nearly the same size and shape arising 
from the ventral end of the infradental lamella (Fig. 23) 
trinidadensis ; go to 26. 
16. Long fine flagelliform hairs on nodes of petiole and postpetiole 
and on gastric dorsum very numerous, too many to count, and 
evidently always > 16 + 20 + 50, or > 86 total (partially 
denuded specimens or those with hairs plastered down can of 
course be deceptive) 1 7. 
Long flagelliform hairs of nodes and gastric dorsum much fewer, 
at most about 8 + 10 + 34, or about 52 hairs total 18. 
17. Dorsal scrobe border on each side produced as a narrow but 
distinctly lamellar margin ; inner mandibular border with a 
minute denticle near the apical third, in addition to the preapical 
tooth ; basal gastric costulae short, coarse, remainder of first 
