New ants of the Australian genus Orectognathus, with a key to the known species (Hymenoptera : Formicidae)

Abstract

Seven species of Orectognathus (= Arnoldidris) are described as new (0. darlingtoni, 0. nanus and 0. parvispinus from north-east Queensland; 0. robustus from eastern Queensland; 0. elegantulus from south-east Queensland; 0. roomi and 0. velutinus from south-east New Guinea), along with notes on some older species, discussion of their likely relationships, and a key to workers of the 26 species now known. Workers of most species are illustrated, chiefly with scanning electron micrographs, and the holdings of the Australian National Insect Collection are briefly reviewed.