6o 
Psyche 
[June-September 
est), in rotten wood (G. B. Fairchild and W. L. Brown leg., no. 
B-86), TL 3.3, HL 0.76, HW 0.52, ML 0.53, WL 0.82 mm; Cl 
68, MI 70 (n — 1), specimen here placed as S. lacacoca; this worker 
has a single extremely minute denticle in the preapical concavity of 
the left mandible, perhaps representing a vestige of a distal preapical 
tooth. Rio Chinillo, Panama Canal Zone (T. E. Snyder leg.), TL 
2. 8-3. 2, HL 0.70-0.75, ML 0.45-0.48, WL 0.72-0.75 mm; Cl 67-71, 
MI 60-66 (n 7), type series of S. lacacoca. 
Though the known variation of the nvcretcs-lacdcoca is consider- 
ably expanded by the new material reported above, this variation is 
mainly away from the direction of S. nevermanni Brown, from Costa 
Rica, a species that is generally smaller, with a relatively shorter head 
and mandibles and narrow infradental lamellae. 
A new species of the T ococae group 
Strumigenys fairchildi new species 
Holotype worker: TL 4.1, HL 0.96, HW 0.72, ML 0.59, WL 
1. 01, scape L 0.68 mm; Cl 75, MI 61. 
Aside from its larger size and relatively longer mandibles, this 
species closely resembles S. tococae Wheeler from the Amazon Basin. 
The upper propodeal teeth are somewhat longer (about as long as 
the distance between the centers of their bases, and about twice as 
long as the lower teeth), and the lamella between the upper and lower 
teeth is lower and more cariniform. The eyes are about the same size 
(greatest diameter about 0.14 mm), and the petiole and postpetiole 
are similar, but with slightly less voluminous spongiform appendages. 
The best distinction lies in the sculpture and pilosity of the nodes and 
gastric dorsum: 
( 1 ) Postpetiolar disc convex, evenly reticulo-punctulate, with only 
feeble anterior traces of longitudinal costulae. First gastric tergite 
finely longitudinally striolate, opaque-sericeous throughout (in S. 
tococae , the gaster is costulate at the base, but otherwise 1 smooth and 
shining) . 
(2) Ground pilosity strongly reduced, virtually absent on nodes 
and gastric dorsum (plentiful and conspicuous in S. tococae). Fine 
erect flagelliform hairs of nodes and gaster shorter and apparently 
fewer than in S. tococae. 
The color is ferruginous yellow, the gaster somewhat brighter yel- 
low than the rest of the body. 
Holotype [MCZ] a unique worker from the wooded ravine next 
to the inn near the top of Cerro Campana, Panama Prov., Panama, 
17 January, i960, at an altitude of 800 to 850 m (G. B. Fairchild 
