308 WHEELER. 



notal stigmata large and slit-shaped as in the female. Petiole broadly 

 and deeply concave abo\-e, its sides and posterior corners produced 

 backward as a pair of large flattened, bluntly pointed projections. 

 Gaster rather short, rather strongly curved, very convex above, con- 

 cave below. Subgenital plate lanceolate, with a sharp median longi- 

 tudinal carina and terminating in two slightly diverging, acuminate 

 points. Stipites subtrapezoidal, with bluntly angular tips; sagittse 

 slender, of e\'en diameter except at the tip which is abruptly expanded 

 and truncated, longer than the volsella? which are slender, tapering, 

 with simple, blunt tips. Legs rather long and slender; claws toothed. 

 ^Yings only moderately long (13 mm.). 



Opaque; very densely and finely punctate, the head, thorax and 

 petiole also A\'ith larger, coarser, rather evenly distributed, piligerous 

 punctures. Such punctures are also present, but much sparser, on 

 the mandibles, legs and sides of gaster. 



Hairs fulvous, long, suberect, moderately abundant, absent on the 

 sides of the thorax and mid-dorsal portions of the more posterior 

 gastric segments, very long and conspicuous on the clypeus, gula, 

 mandibles, front, scutellum, epinotum, petiole, base, sides and tip of 

 the gaster, more reclinate and of uneven length on the pro- and meso- 

 notum. There are also a few long hairs on the antennal scapes and 

 tips of the basal funicular joints on the extensor surface. Pubescence 

 fulvous, short, dense, appressed, confined to the antennal fimiculi and 

 to the dorsal surface of the gaster, which has a vehety appearance. 



Dark brown or blackish; petiole, tibiie, articulations of thorax and 

 legs and tips of mandibles somewhat paler and more reddish; gaster, 

 tarsi and tips of petiolar projections much paler, brownish red. Wings 

 slightly yello\\-ish, with dark brown veins. 



Described from two females taken at Kartabo, British Guiana, 

 July 21st, 1920, two males taken at light in the same locality July 20; 

 two males taken by ]\Ir. Wm. Beebe, also at Kartabo June 20, 1919, 

 three males from Para, Brazil (C. F. Baker), and numerous mature 

 pupal males taken from the colony containing the two females. 



The female burchelli exhibits a ^•e^y peculiar development of the 

 thorax compared \\-ith the known females of Acamatm, which are all 

 much simpler in structure, as may be seen by comparing Figure 2 

 with the figure of the carol inensc female (Fig. 8). Judging from the 

 descriptions and figures of Andre and Luederwaldt, the known Labidus 

 females are intermediate between those of the two other subgenera, as 

 would be expected from a study of the workers and males. Undoubt- 

 edly the old burchelli queen, A\-ith fully expanded gaster, must be a 



