A review of the present-day Australian species of the gastropod subgenus Rissoina (Rissolina) (Rissooidea: Rissoinidae) with descriptions of two new species

The Australian species of the rissoinid subgenus Rissoina (Rissolina) are reviewed based on the examination of material mainly from the collections of the Australian Museum (Sydney). A total of 15 species is recognized, two of which are new: Rissoina (Rissolina) backeljaui spec. nov. and R. (Rissolina) ponderorum spec. nov. Two species are (re)described using open nomenclature. Lectotypes are selected for R. mercurialis R. B. Watson, 1886 and R. signata O. Boettger, 1893. Some anatomical aspects of R. angasii Pease, 1871, R. duclosi Montrouzier, 1866, R. heronensis (Laseron, 1956) and R. ponderorum spec. nov. are described.