A catalogue of the ants of Paraguay (Hymenoptera: Formicidae) Author Wild, Alexander L. text Zootaxa 2007 1622 1 55 journal article 10.5281/zenodo.179222 9584df9a-a4a2-49bb-a256-cb99776f4dc8 1175-5326 179222 Hypoponera opaciceps (Mayr 1887) . Ponera opaciceps Mayr 1887: 536 . [ lectotype w examined, NHMW; Santa Catharina, Brazil ] Hypoponera opaciceps (Mayr) . Taylor 1967: 11. Ponera opaciceps var. postangustata Forel 1908b: 343 . NEW SYNONYMY . [ holotype w examined, MHNG; San Bernadino, Cordillera, Paraguay (Fiebrig)]. Hypoponera opaciceps postangustata (Forel) . Kempf 1972: 123. Forel (1908h) distinguished the variety postangustata from H. opaciceps on the basis of having a more convex head shape, but having examined and photographed both Mayr’s and Forel’s types , I can find no discernable difference in shape. Both ants are remarkably similar in most respects except for color- the H. opaciceps type is piceous while H. postangustata is ferruginous. In any case, H. opaciceps is variable in many characters even within nest series. Forel’s H. postangustata type falls well within the bounds of variation of H. opaciceps and I synonomize it here.