Polyrhachis (Campomyrma) gravis

Clark, J., 1930, New Formicidae, with notes on some little-known species., Proceedings of the Royal Society of Victoria 43, pp. 2-25 : 15-16

Polyrhachis (Campomyrma) gravis , n. sp. (Text-fig. 1, Nos. 12, 12a.)

Worker.-Length, 7.5-9 mm.

Black. Mandibles, apical segments of the antennae, legs and four posterior coxae reddish brown, anterior coxae black. In a few examples the tibiae are darker than the femora.

Shining. Head very finely striate-rugose longitudinally. Clypeus slightly rugose behind, punctate in front. Mandibles very finely and densely striate longitudinally. Pronotum longitudinally arched striate-rugose, diverging outward behind, almost transverse in front. Mesonotum and epinotum longitudinally striate-rugose, the Striae following the contour of the segments. Sides of the thorax longitudinally striate, mudi stronger than on the dorsum, declivity transversely striate. Node transversely striate in front and behind. Gaster finely and microscopically striate-punctate, with a longitudinally arched direction. Anterior coxae finely transversely rugose.

Hair yellow, erect, very short and sparse throughout, except on the apex of the gaster.

Head slightly longer than broad, the occipital border appearing strongly convex, but really composed of three straight portions, the base, or centre, short, the portions from the base to the angles three times longer than the base, sides convex. Frontal carinae parallel, or very feebly diverging behind. Clypeus broad and convex, not cannate, the anterior border broadly produced, straight, feebly crenulate. Eyes large and convex, placed at the posterior angles. Scapes extending beyond the occipital border by more than half their length; first segment of the funiculus slightly longer than the second, the others subequal to the apical. Mandibles armed with six large, sharp teeth. Thorax one and one-half times longer than broad. Pronotum almost twice as broad as long, convex and marginate in front and sides, the posterior border almost straight, the anterior angles bluntly produced. Mesonotum broader than long, one and a-half times broader in front than behind, the sides marginate. Epinotum one-third longer than broad, fully twice as broad in front as behind, the sides strongly marginate, produced behind as short, sharp teeth, directed upward, their length equal to their distance apart at the base. The declivity abrupt, concave, as long as the dorsum. Node thick, broader than long, furnished with four sharp, slender spines, the middle pair slightly longer than the lateral pair, longer than their distance apart, parallel, the points of the lateral pair level with the base of those in the middle. First segment of the gaster strongly margined in front, and anterior two-thirds of the sides. Legs long and slender.

Habitat.-Central Australia: Burt Plains (C. Barrett).