1961] 
Brown — Strumigenys 
6 3 
est, and foraging on surface of log in degraded rain forest. Panama 
Canal Zone: Barro Colorado Island (J. Zetek leg.), a single worker. 
This species is here reported from the American mainland for the 
first time ; apparently it is widespread. 
Strumigenys hindenburgi Forel 
Strumigenys Hindenburgi Forel, 1915, Bull. Soc. Vaud. Sci. Nat., 50: 357, 
worker. Type loc. : “Argentine,” La Plata from label on syntypes. Syntypes 
in Coll. Forel, Museum d’Histoire Naturelle, Geneva, and MCZ, several 
examined. 
Strumigenys hindenburgi , Kempf, 1958, Stud. Ent. (n.s.) 1:555, record from 
10 km sw of Agudos, S. Paulo State, Brazil, among dry leaves in wooded 
gully. 
Worker: TL 2. 8-3. 2, HL 0.60-0.69, ML 0.38-0.40, WL 0.63-0.71 
mm; Cl 83-88, MI 58-64. Measurements from 3 syntypes and 6 
additional Argentinian specimens representing 3 nest series. 
Within the lanuginosa group, this species is distinguished by its 
large size and relatively broad head, as well as the following charac- 
ters : 
(1) Dorsolateral borders of the head (dorsal scrobe borders) on 
each side produced as a narrow but distinct lamellar margin that grad- 
ually narrows posteriad and ends in a shallow concavity behind the 
level of the eye. 
(2) Mandibles each with an extra minute preapical denticle, best 
seen in oblique view in dark silhouette against a bright background, 
near the apical third of the shaft. 
(3) Basigastric costulae extending less than half the length of the 
first segment, the rest of which is smooth and shining. 
(4) Lateral occipital margins each with only one flagellate hair, 
arising from the concavity at the end of the lamellate dorsolateral 
margin. 
(5) Occiput, pronotum and postpetiolar disc with traces of feeble 
reticulate rugulation superimposed on the basic densely punctulate 
sculpture. 
Color medium ferruginous ; legs, mandibles and antennae more 
yellowish ; gaster mostly brown. 
Pseudogyne or ergatoid female from Itatiaia: TL 2.7, HL 0.60, 
HW 0.49, ML 0.34, WL 0.60 mm; Cl 82, MI 57. This small in- 
dividual has the mesonotum developed in the direction of the full 
female, with raised margins dorsad, and the differentiated scutellum 
acutely projecting posteriad. The petiolar and postpetiolar nodes are 
wide, as expected in females of this genus, but the gaster is not un- 
usually bulky for a worker. A tiny apparent remnant of a median 
ocellus occurs in the central vertex. T his specimen appears to me to 
