Abstract
Rugosothynnus gen. nov. (type species Rhagigaster corrugatus Turner, 1910) is erected for 12 Rhagigaster-like species. Nine species are described and illustrated from Australia: R. brunneus sp. nov., R. clypeatus sp. nov., R. confusus sp. nov., R. depressus sp. nov., R. fulvescens sp. nov., R. houstoni sp. nov., R. monteithae sp. nov., R. neocorrugatus sp. nov. and R. schichai sp. nov. New combinations are proposed for R. burnsi (Given, 1959), comb. nov., R. corrugatus (Turner, 1910), comb. nov. and R. tristis (Smith, 1859), comb. nov. (all previously from genus Rhagigaster Guérin-Ménéville, 1838). A key to both sexes of all species is provided except for the females of R. clypeatus sp. nov., R. depressus sp. nov., R. neocorrugatus sp. nov. and R. schichai sp. nov. which are unknown.