Abstract
In this study we synonymise the genus Decamorium Forel under Tetramorium Mayr, revise the new T. decem species group by providing a diagnosis of the group, an illustrated identification key to species level, and worker-based species descriptions for all five species, which include diagnoses, discussions, images, and distribution maps. The following species are revised in this study: T. decem Forel, comb. r., T. raptor sp. n., T. uelense Santschi, comb. r., T. ultor Forel, comb. r., stat. r. & stat. n., and T. venator sp. n. In addition, we also designate lectotypes for T. decem, T. uelense, and T. ultor.