Psalidomyrmex obesus, 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 : 92-93

Psalidomyrmex obesus , new species

Text Figure 19

Worker.- Length nearly 12 mm.

Very similar to procerus but differing in the following characters: the body is distinctly more robust, the head being rectangular, and without the mandibles as broad as long, the thorax with more rounded surfaces and a swollen appearance. The mandibles are like those of procerus but slightly broader at the angle between the basal and apical borders and the tips are less curved. The antennal scapes reach the posterior corners of the head; funicular joints 3 to 8 as long as broad, 9 and 10 slightly longer than broad. On the thorax the mesoepinotal suture is more distinct than in procerus and there is a narrow median longitudinal furrow on the posterior half of the pronotum as well as on the base of the epinotum. The petiole in profile is much shorter and higher and, seen from above, much broader in proportion to its length than in procerus , being very distinctly broader than long, flat and truncated posteriorly, more rounded in front, with the anteroventral tooth long and rather acute.

The sculpture differs from that of procerus as follows: the longitudinal rugae covering the mandibles are distinctly coarser, the surface of the head and thorax is more opaque, the foveola; being somewhat smaller, shallower and less shining, though about as numerous and the striolae of the interfoveolar surface less sharp. The petiole and postpetiole are smoother and more shining than the head and thorax unci the interfoveolar sculpture is so feeble as to appear more or less coriaceous or alutaceous. The first gastric segment is longitudinally, not arcuately striolate. The femora are transversely, the scapes and tibiae longitudinally striolate as in procerus .

Erect hairs somewhat more numerous on the dorsal surface of the head and pronotum and on the antennal scapes.

Nearly coal black, darker than procerus , legs, excluding the coxa;, mandibles, clypeus, frontal carinae, antennae, and terminal gastric segments castaneous as in procerus .

Described from two specimens from Medje from the stomach of a toad (Bufo superciliaris) collected by Lang and Chapin. This form is certainly distinct and is, in my opinion, more than a subspecies of procerus .