The ants collected by the American Museum Congo Expedition. Author Wheeler, W. M. text Bulletin of the American Museum of Natural History 1922 45 39 269 http://plazi.org:8080/dspace/handle/10199/17097 journal article 20597 Plagiolepis Mayr Worker medium-sized to very small, monomorphic or feebly polymorphic. Mandibles rather narrow, with oblique, usually 5-toothed, apical borders. Clypeus large, convex, carinate or subcarinate, lozenge-shaped, its anterior border arched and projecting somewhat over the bases of the mandibles. Maxillary palpi 6-jointed, labial palpi 4-jointed. Frontal carinae short, subparallel, rather far apart. Frontal area poorly denned. Antennae 11-jointed, inserted very near the clypeal suture, the funiculi slender, gradually thickened towards their tips, the first joint long, the remaining joints gradually lengthening distally, the terminal joint elongate. Eyes moderately large and flat, placed in front of the middle of the head. Ocelli usually absent. Thorax short, more or less constricted in the mesonotal region, the epinotum simple and unarmed. Petiole with its scale anteriorly inclined, its superior border entire. Gaster rather voluminous, elliptical. Legs slender. Gizzard with the calyx strongly reflexed, parasol-shaped. Female much larger than the worker. Head small, thorax and gaster massive, the mesonotum somewhat flattened above, the gaster elliptical. Antennae 11-jointed. Wings long, with one cubital cell and usually without a discoidal cell. Male somewhat smaller than the female. Mandibles acutely toothed. Frontal area large. Antennae 12-jointed, with long scapes; funiculi with elongate first joint. Thorax voluminous, mesonotum large, flattened above, covering the small pronotum. Petiole as in the female. External genital valves large, rounded. Wings as iu the female. Pupae enclosed in cocoons. This genus is peculiar to the warmer parts of the Old World (Maps 34 and 35) and is represented by the largest and most numerous species in the Ethiopian Region. Two of the latter, P. custodiens and steingroveri, resemble our northern species of Formica in stature and structure. A single medium-sized species, P. longipes (Jerdon) , has been widely distributed by commerce in the Old World tropics and has also gained a footing in Mexico. Another species, P. nuptialis Santschi , recently discovered by Dr. Hans Brauns in the Cape Province, is parasitic on P. custodiens (vide infra). So far as known, the species of Plagiolepis nest in the ground, making crater nests or tunneling under stones, with the single exception of P. mediorufa , which inhabits plant-cavities. Map 34 Distribution of the genus Plagiolepis . Map 35. Distribution of tho subgenus Anacantholepis (crossed area) of Plagiolepis and of the allied genus Stigmacros (dotted area) Santschi has recently separated the genus into three subgenera: Plagiolepis , sensu stricto, Anacantholepis , and Anoplolepis , on the structure of the mesonotum.