Pheidole mylognatha Wheeler, 1922, new species

Pheidole mylognatha, new species Text Figure 33 Soldier.- Length 6 mm. Head large, subrectangular, 2 mm. broad and 2.3 mm. long, as broad in front as behind, with straight, parallel sides, deeply and angularly excised posterior border, with depressed occipital surface and faint depressions on the sides of the front for the antennal scapes. Occipital and frontal groove deep. Eyes small, flat, at, the anterior third of the head. Mandibles very convex, probably bluntly bidentate at apex but the apical borders are worn away in the specimen. Clypeus very short, concave and indistinctly carinate in the middle, swollen and convex on the sides; the anterior border rather deeply emarginata in the middle and sinuate on each side. Frontal carina, short, diverging; frontal area indistinct. Antennae small and slender; scapes when bent outward not reaching to the eyes, terete and slightly curved at the base; joints 2 to 8 only slightly longer than broad; club distinctly shorter than the remainder of the funiculus. Thorax small, much shorter than the head and less than half as wide through the pronotum, which is bluntly tuberculate on the sides both above and below. Mesonotum short, rapidly sloping to the pronounced mesocpinotal constriction, anteriorly with a feeble transverse impression and a small, sharp transverse ridge behind it. Epinotum distinctly broader than long, broadly concave and sloping in the middle, the base shorter than the declivity, marginate on the sides, the marginations continued into the spines which are short, acute, and erect, a little longer than broad at their bases, less than half as long as their interval. Petiole small and short, less than twice as long as broad, broader behind than in front, the node blunt, transverse, and emarginate in the middle. Postpetiole broader than long, its sides produced as short, acute, backwardly directed spines, the distance between the tips of which is about three times the width of the petiole. Gaster smaller than the head, elliptical, flattened dorsoventrally. Femora only moderately thickened in the middle. Shining; mandibles sparsely punctate in the middle, coarsely striated at the base and along the apical margins. Clypeus lugulose, irregularly in the middle, longitudinally on the sides. Anterior half of head longitudinally rugose, with punctate interrugal spaces, the punctures becoming more numerous on the very feeble scrobe-like depressions; posterior half of head very smooth and shining, with a few sparse, piligerous punctures. Thorax loosely rugose and somewhat reticulatepunctate on the sides, concavity of epinotum finely transversely striated. Petiole and postpetiole indistinctly punctate-rugulose, the latter smoother and shining above. Gaster and legs smooth and shining, with sparse, piligerous punctures. Hairs whitish, delicate, sparse, erect or suberect on the body, shorter, more abundant and appressed on the legs; almost absent on the scapes. Rich castaneous brown; gaster, except the base of the first segment, darker, almost black; legs and funiculi a little more reddish, the femora infuscated in the middle. Worker.- Length 2 mm. Head a little longer than broad, as broad in front as behind, with feebly convex sides and feebly concave posterior border. Eyes rather convex, just in front of the middle of the sides. Mandibles with the whole apical border very finely denticulate. Clypeus convex, its anterior border entire, broadly rounded. Antennal scapes extending fully one-fourth their length beyond the posterior border of the head. Thorax and petiole very similar to those of the soldier but the mesonotum more sloping and with much feebler transverse convexity. Postpetiole only one and one-half times as broad as the petiole, its sides produced as short angles or conules. Shining; mandibles finely and indistinctly striate; clypeus and cheeks longitudinally rugulose; area between the frontal carinae and the eyes reticulate, remainder of head very smooth and shining. Pronotum smooth and shining above, reticulate on the sides; meso- and epinotum subopaque, densely punctate; petiole and postpetiole more finely punctate, the nodes above smooth and shining like the gaster and legs. Pilosity and color much as in the soldier, but the fine appressed hairs on the scapes as abundant as on the legs. Described from a single soldier and two workers taken at Banana by Lang and Chapin. This species is related to P. schultzei Forel from the Kalahari Desert, as I find by comparison with cotypes received from Prof. Forel. The head of the schultzei soldier, however, has more convex sides, more rounded posterior corners, a less deeply excised posterior margin, less deeply impressed occipital groove, longer antennae, and a very different color, being yellowish red, with the legs and base of gaster yellow. The worker schultzei departs further from that of mylognatha in being more slender, with decidedly longer legs and antennae, in lacking spines on the epinotum and in having a longer postpetiole, which is scarcely angular on the sides. It is sordid or brownish yellow, with the head darker behind and on the sides.
Published as part of Wheeler, W. M., 1922, The ants collected by the American Museum Congo Expedition., pp. 39-269 in Bulletin of the American Museum of Natural History 45 on pages 134-135