Platythyrea gracillima, Wheeler, W. M., 1922

Wheeler, W. M., 1922, The ants collected by the American Museum Congo Expedition., Bulletin of the American Museum of Natural History 45, pp. 39-269 : 59-60

Platythyrea gracillima , new species

Worker (Fig. 5a and 6).- Length 9 mm.

Very slender. Head, excluding the mandibles, fully one and one-half times as long as broad, a little broader in front than behind, with very feebly convex sides and feebly excised posterior border. Mandibles rather long, moderately convex, their apical border with about 10 distinct teeth. Clypeus large, rather flat, more convex in the middle behind, with broadly rounded, entire anterior border and distinct posterior suture. Frontal carina; very prominent, fused posteriorly. Eyes small, a little in front of the middle of the sides of the head. Antennal scapes long and stout, extending fully one-fourth their length beyond the posterior corners of the head; funiculi lacking, except the first joint, which is three times as long as broad. Thorax long and narrow, laterally compressed, especially in the meso- and epinotal regions; broadest through the pronotum, which is as broad as long and as broad as the head, rounded in front and on the sides. Mesonotum longer than broad. Promesonotal suture very distinct, mesoepinotal suture obsolete. In profile the dorsal outline of the thorax is nearly straight and horizontal; the base of the epinotum nearly twice as long as the declivity. The latter is abrupt, submarginate on the sides, which are obtusely ungulate. Petiole laterally compressed; seen from above a little more than twice as long as broad, with straight, parallel sides: in profile evenly rounded in front, straight above and very sharply and deeply concave behind, the ridge between the dorsal and posterior surface being narrow, transverse and feebly emarginate in the middle. At its posterior end the petiole is fully three-fifths as high as long. Postpetiole distinctly longer than broad, as broad as the gaster behind and not separated from it by a perceptible constriction, narrowed to the breadth of the petiole in front. First gastric segment as long as broad, the remaining segments short, telescoped into it. Legs rather long.

Slightly shining; mandibles more shining, finely and densely punctate; remainder of body even more finely and densely punctate; with a few larger, but very shallow and indistinct, superadded punctures on the head, thorax and petiole.

Hairs absent; pubescence yellowish gray, very short and fine, rather evenly distributed like dust over the whole body and the appendages, longer and more oblique on the mandibles.

Black; mandibles, clypeus, frontal carinae, antennae, legs, including the coxae, posterior corners of the head, dorsal surface of pronotum, epinotum and petiole, and posterior border of postpetiole and first gastric segment, red; remaining gastric segments yellow.

Described from a single rather poorly preserved specimen from Avakubi (Lang and Chapin), taken from the stomach of a toad (Bufo regularis).

This species is unlike any of which I have seen specimens or descriptions in the shape of the head and body and especially of the petiole and gaster. In certain respects it approaches viehmeyeri Santschi of German East Africa, but is much smaller ( viehmeyeri measures 13 mm.), and has densely punctate instead of striolate and sparsely punctate mandibles; the latter are denticulate; the head and antennae are longer; the thorax not submarginate on the sides; the pronotum is not longer than broad; the mesonotum is longer than broad; the color is very different; etc.