Lymnaea palustris var. fallaciosa Roffiaen 1868

Lymnaea palustris var. fallaciosa Roffiaen, 1868 Fig. 2 A Limnæa palustris var. fallaciosa Roffiaen, 1868: 78, pl. 1, fig. 6. Type material. RBINS I.G.7065 / MT.4174: 3 syntypes, ex Colbeau coll. RBINS I.G.28242 / HIST.180: 6 possible syntypes. RBINS I.G.7065 / HIST.181: 1 possible syntype. Type locality. Switzerland: Brunnen, along road to Schwyz. “ […] Brunnen, dans un fossé de la plaine, longeant la route de Schwyz ” (Roffiaen 1868: 79). Taxonomic status. Junior synonym of Stagnicola palustris (O. F. Müller, 1774) (cf. Servain 1882; Hubendick 1951; Vinarski 2024). Discussion. Lot RBINS I.G.7065 / MT.4174 stems from the collection of Jules Colbeau, comes from the type locality (Brunnen), and the specimens are a good match to the published illustration (Roffiaen 1868: pl. 1, fig. 6); thus, the three specimens it contains are here considered syntypes. Lot RBINS I.G.28242 / HIST.180 stems from the type locality but bear no other information regarding their former owners. The six specimens match morphologically the syntypes in the previous lot and, thus, are considered here as possible syntypes. Similarly, lot RBINS I.G.7065 / HIST.181 has 1 specimen from Colbeau’s collection whose location is given as “ Schwyz ” on the label, together with an indication that this specimen belonged to the study of Roffiaen. While the type locality of the present taxon could be generously interpreted as containing Schwyz, we deem it safer to consider the present specimen as a possible syntype. Though conchologically, this variety corresponds well to a widespread Stagnicola palustris, there is a possibility that Roffiaen’s shells could belong to S. fuscus (C. Pfeiffer, 1821) instead. The latter can only be distinguished with certainty from S. palustris by anatomical and / or genetic investigations (Welter-Schultes 2012; Glöer 2019). The range of S. fuscus covers much of central and western Europe, including Switzerland (Welter-Schultes 2012).