R. (Exsertiana), Bourguignat, 1883

Vinarski, Maxim V., Aksenova, Olga V. & Bolotov, Ivan N., 2020, Taxonomic assessment of genetically-delineated species of radicine snails (Mollusca, Gastropoda, Lymnaeidae), Zoosystematics and Evolution 96 (2), pp. 577-608 : 577

Subgenus Exsertiana Bourguignat, 1883

Exsertiana Bourguignat 1883: 88.

Raffrayana Bourguignat 1883: 88.

Radix (Exsertiana) - Aksenova et al. 2018a: 6, 9

Type species.

This subgenus contains two molecularly-defined species of Radix having an almost entirely tropical distribution - Radix natalensis (Krauss, 1848) and R. rufescens (Gray, 1822).

Remark.

Bourguignat (1883: 88), in his lengthy article devoted to classification of continental molluscs of Abyssinia, established two new groups of species within the genus Limnaea - Exsertiana and Raffrayana . He did not give any diagnoses for the two taxa, only lists of species included there. In both cases, these species are currently recognised as junior synonyms of R. natalensis (fide Hubendick 1951; Brown 1994). We selected Exsertiana as a name for designation of a lymnaeid clade containing R. natalensis . Since Bourguignat (1883) did not indicate the type species for Exsertiana , we designate here Limnaeus natalensis var. exsertus Martens, 1866 as the type taxon for this subgenus. This species is usually regarded as identical to R. natalensis (Hubendick, 1951), though Mandahl-Barth (1954) accepted it as a valid species, closely related to the latter.