1961] 
Brown — Strumigenys 
61 
and W. L. Brown leg.). The worker was found walking on a rotten 
stick lying on the leaf litter on the shaded slope of the ravine ; hasty 
search of the litter and soil nearby failed to uncover more specimens. 
Since the very closely related S. tococae was found at Belem, Brazil, 
nesting in foliar sacs of the plant Tococa, it is possible that S. fairchildi 
was also nesting in a plant cavity above the ground. Since the rela- 
tionships of S. fairchildi were not recognized until it was critically 
examined in the laboratory, the possibility of a plant-cavity habitat 
was not investigated in the field. 
Group of S. lanuginosa Wheeler 
Two species, S. lanuginosa Wheeler and S. hindenburgi Forel, share 
a number of traits that apparently indicate a fairly close relationship 
between them : Mandibles lying close together at full closure, their 
bases sharply narrowed from the outside; apical fork moderate in 
length, with a single intercalary tooth; inner (masticatory) margin 
concave near apex, the concavity with a short but acute preapical tooth 
( S . hindenburgi has an additional minute denticle near the apical 
third of the margin). Clypeus broadly triangular, with convex an- 
terior margin. Antennal scape slender, tapered toward both ends, 
very slightly curved at basal third. 
Pronotum with humeral angles developed, bluntly tuberculate; an- 
terior margin present (weak in S. lanuginosa) ; alitrunk in side view 
with convex dorsal profile, broken only at the impressed metanotal 
groove. Propodeal teeth of modest size, but acute, each subtended by 
a low, concave infradental lamella ending in a ventral convexity. 
Petiole distinctly pedunculate and with a short, dorsally rounded 
node; postpetiolar disc convex; both nodes with complete and well- 
developed spongiform appendages. Gaster normal in form, with a 
strong anterodorsal spongiform margin and a thick anteroventral 
spongiform pad ; basigastric costulae well developed. 
Head, alitrunk and both nodes densely and finely reticulo-punctu- 
late, opaque; postpetiolar disc usually with weak rugulosity or costu- 
lation superimposed. Underside of gaster smooth and shining; 
mandibles weakly shining in some lights, punctulate; legs and an- 
tennae finely and densely punctulate. Sides of pronotum, anterolateral 
surfaces of anterior coxae, and lower lateral surfaces of infradental 
lamellae of propodeum with patches of fine reclinate hairs and fre- 
quently encrusted with whitish material; apparently these represent 
secretory areas. 
Ground pilosity of head, promesonotum, posterior propodeun; 
scapes and legs consisting of fine, abundant reclinate and arched-rec.lin- 
