Worker.-Small, monomorphic or very rarely (in one South African species, T. ambigua Emery , according to Arnold) with the head dimorphic. Body long and slender. Head subrectangular, with large or very large, moderately convex eyes, onethird to two-fifths as long as the head; ocelli vestigial, often absent. Mandibles short and stout, with distinct basal and apical border, the latter with a small number of subequal teeth. Clypeus extremely short, steep, elevated in the middle but not extending back between the frontal carinae, the anterior border emarginate, dentate or crenulate. Frontal carinae small, short, closely approximated, lobular anteriorly, often slightly diverging behind. Maxillary palpi 5-jointed; labial palpi 4-jointed. Antennae short, 12-jointed, the funiculi somewhat thickened at their tips, without distinct clava. Thorax narrow, with well-developed premesonotal and mesoepinotal sutures and a distinct metanotal sclerite, often constricted in the mesoepinotal region. Epinotum large and rather high, always unarmed. Petiole and often also the postpetiole pedunculate, rather long and slender, both with low, rounded nodes, their ventral portions not swollen or with stout teeth. Gaster narrow and elongate oval, with well-developed, exserted sting. Middle and hind tibiae with pectinated median spurs; claws toothed.
Female very similar to the worker and scarcely larger, winged; the wings short, the anterior pair with a discoidal, two closed cubital cells and a rather narrow, closed radial.
Male scarcely smaller than the worker and very similar except for the wings. Head shorter. Eyes and ocelli well developed, convex. Mandibles well developed, with dentate apical borders. Antennae 12-jointed, the scape but little longer than the second funicular joint, the first joint much shorter than the second, not swollen. Mesonotum depressed, not overarching the pronotum, without Mayrian furrows and with very feeble parapsidal furrows. There is, at least in some species, a concavity in the pro- and mesosterna, extending dorsally nearly to the mesonotal scutum. External genitalia well developed, exserted. Cerci present. Wings as in the female.
Larva hypocephalic, with papillary exudatoria on the three thoracic and first abdominal segments. Dorsal surface with long straight hairs, hooked at their tips.
Donisthorpe (1916, Ent. Record, XXVIII, pp. 242-244) has shown that Sima Roger, the name used by most authors for this genus, must be sunk as an isonym of Tetraponera F. Smith, contrary to Emery's contention(1915, Zool. Anzeiger, XLV, p. 265). The case seems to be very clear, as Smith founded his genus Tetraponera (1852) on two species, atrata (= Eciton nigrum Jerdon ) and testacea. The latter he afterwards (1855) placed in the genus Pseudomyrma. Roger founded his genus Sima in 1863 on S. compressa Roger (= Pseudomyrma? allaborans Walker ). Later (1900) Emery separated the genus Sima into two subgenera, Sima, sensu stricto, and Tetraponera , the former with, the latter without ocelli in the worker and selected Eciton rufonigrum Jerdon as the type of Sima, sensu stricto. This was an improper procedure, since the worker of Roger's type species, S. allaborans has no ocelli.
Examination of the males of several of the Indomalayan species of Tetraponera shows that they all have 12-jointed antennae. This is also true of the males of Pachysima, Viticicola , and even of Pseudomyrma and, hence, of the whole tribe Pseudomyrmini of Emery. Nevertheless, in his recent classification of the Myrmicinae (1914, Rend. Accad. Sc. Bologna, p. 34) he cites the males of this tribe as having 13-jointed antennae. Bingham and Arnold also give the same number for Tetraponera , and Santschi, who was the first to describe the male of Pachysima aethiops , failed to notice that it has 12-jointed antennae.
The genus Tetraponera is distributed over the Ethiopian, Malagasy, Indomalayan, Papuan, and Australian Regions (Map 18), being best represented in the Ethiopian and Indomalayan. One species, T. bifoveolata, (Mayi"), was taken by Dr. W. M. Mann as far north as Palestine. The species all nest in plant cavities (dead wood, twigs, stems of lianas, acacia spines, etc.) and are very quick in their movements. Their habits throughout are very similar to those of the allied Neotropical genus Pseudomyrma. The species of the latter, however, are much more numerous and constitute an abundant and conspicuous part of the Neotropical ant-fauna, whereas the species of Tetraponera are comparatively rare ants.
Map 18. Distribution of the genera Tetraponera (crossed area) and Viticicola (known localities indicated by crosses).