On unavailable genus-group names introduced by Tom Iredale for Australian non-marine gastropods: nomenclatural clarifications and descriptions of new genera

Among non-marine genus-group names of Australian Gastropoda established by Tom Iredale (1880-1972), 42 were introduced without a description, and are thus unavailable under the International Code of Zoological Nomenclature. Several of these names were made available, often inadvertently, in subsequent literature, but others have remained unavailable. We clarify the nomenclatural availability of all 32 originally unavailable names, the nomenclatural availability of which was not subsequently properly assessed. Most notably, the names Arnemelassa, Figuladra, Malandena, Meridolum, Nannochloritis, and Turrisitala continue to be used in taxonomic literature to this day, although they are unavailable. Where no other available name can be applied, these genera are herein described as new (Arnemelassa n. gen., Figuladra n. gen., and Nannochloritis n. gen.) to stabilise the nomenclature of Australian non-marine gastropods.