Cardiocondyla Emery Worker minute, smooth, almost hairless. Clypeus projecting over the bases of the mandibles, steep in front, with rounded anterior border. Frontal area strongly impressed. Frontal carinae short and straight. Eyes well developed; ocelli lacking. Mandibles broad, triangular, dentate. Antennae 12-jointed, with long first funicular joint and 3-jointed club, the last joint very large. Promesonotal suture indistinct; mesoepinotal constriction well developed. Epinotum armed with spines or teeth. Petiole with long peduncle and small, rounded node. Postpetiole conspicuously large, cordate or transversely elliptical. Gaster formed in large part by the first segment. Female winged (except in C. emeryi Forel), somewhat larger than the worker; head of the same shape but with ocelli. Pronotum not covered by the mesoscutum in front. Petiole and postpetiole usually broader than in the worker. Wings with reduced venation; pterostigma near the middle of the costal border; one closed cubital cell; distal portions of radius and cubitus obsolete; brachius not developed beyond the nervulus but bending up into the submedius. According to Emery, the female of C. emeryi is wingless and has the posterior ocelli vestigial. Male usually ergatomorphic but winged in C. emeryi. In this form the antennae are 13-jointed but in ergatomorphic males they are 10- to 12-jointed; with long scape and more indistinct club. Petiole and postpetiole resembling the corresponding segments of the female, in the male of emeryi much as in the worker.

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 page 149