Myrmicaria salambo, new species

Plate IX, Figures 1 and 2; Text Figure 37

Worker.- Length 6 to 7 mm.

Of rather uniform stature and closely resembling eumenoides but a little more elongate. Head relatively smaller, as broad as long, excavated behind, convex above, flattened below. Mandibles 5-toothed. Clypeus ccarinate, with entire anterior border. Eyes somewhat larger and more convex than in eumenoides. Thorax very similar but premesonotal suture very distinct, impressed, the mesonotal lobes less compressed, their posterior outline in profile less abrupt, more sloping so that the mesoepinotal impression, though deep, is shallower and less acute than in eumenoides and appears longer. Epinotal spines longer, slightly sinuous, with very feebly upturned points, directed backward and slightly outward. Base of epinotum longitudinally concave. Peduncle of the petiole longer than the node, which is thick and evenly rounded, not compressed laterally above. The ventral surface of the petiole armed below with two long, delicate hyaline spines, which curve towards each other and enclose an elliptical space. Postpetiolar node of the same size and shape as that of the petiole, its ventral surface straight in profile, not bulging nor angulate in front. Gaster and legs of the usual shape, the former with a straight, anterior border.

Shining; mandibles coarsely longitudinally striated; clypeus smooth in the middle, with a few rugules on the sides. Rugosity of head, thorax, and pedicel much as in eumenoides, but the rugae on the dorsal surface of the head and thorax less numerous and less pronounced, without distinct anastomoses; sides of the head with finer and less distinct rugules, so that the surface is more shining. Gaster opaque and very finely punctate only at the extreme base above, otherwise shining. Legs and scapes shining, finely striate.

Hairs dark brown, in length and arrangement much like those of eumenoides.

Reddish brown; gaster brownish yellow; legs, including the coxae and lower pleurae, darker than the thorax. Mandibular teeth and antennae blackish.

Described from numerous specimens taken at Garamba (Lang and Chapin) attending scale insects on the buds of a Protea which is shown in Plate IX.

This form is so closely related to eumenoides that it might, perhaps, be regarded as a subspecies. It is easily recognized by the unique ventral appendages of the petiole. These are so brittle that they are easily broken off, but their basal insertions on the low hyaline lamella in the midventral line of the petiole are usually discernible. Evidently salambo is also related to M. striata Stitz, specimens of which I have not seen.