Lymnaea stagnalis var. productissima Roffiaen 1868

Lymnaea stagnalis var. productissima Roffiaen, 1868 Limnæa stagnalis var. productissima Roffiaen, 1868: 78: pl. 1, fig. 5. Type material. Not located. Type locality. Switzerland: Magadino, Lago Maggiore. “ Lac Majeur à Magadino ” (Roffiaen 1868: 78). Taxonomic status. Junior synonym of Lymnaea stagnalis (Linnaeus, 1758) sensu lato (cf. Hubendick 1951; Vinarski 2024). Discussion. There is only one lot (RBINS I.G.7065 / HIST.372, containing 7 shells) in the collection identified as Roffiaen’s taxon, collected in the type locality (“ Lac Majeur Magadino ” on the label). There is unfortunately no further collection data for this specimen lot, so it cannot be ascertained whether these shells came from Roffiaen. In any event, while the specimens do represent Lymnaea stagnalis, they are only about half the size of Roffiaen’s illustrated adult specimen (Roffiaen 1868: pl. 1, fig. 5). Consequently, the shell morphology of these specimens does not correspond with Roffiaen’s diagnosis (“ Coguille très-allongée et efilée à dernier tour moins ventru que chez le type ”, i. e., very elongated and tapered shell with body whorl less rounded than in the type; Roffiaen 1868: 78). Thus, these specimens are likely not types of Lymnaea stagnalis productissima. Being collected from a large lake, the shells most probably belong to a “ lacustrine ” morph of L. stagnalis sensu lato, which is characterized by reduced body size and shortened spire (see Geyer 1929; Hubendick 1951).