Montenegro: Skadar Lake, River Gostiljska Reka, 42°17'09.05"N, 19°14'17.35"E, 25.iv.2008 Pešić; River Piva near Mratinje Dam, 43°16'23"N, 18°50'32"E, 20.viii.2010; Pljevlja town, spring in village Vrulja, 21.x. 2010 Pešić; River Zeta near Podgorica, vi. 1982, Glöer.

In addition to Ancylus fluviatilis we found another Ancylus sp. clearly different from the former species by the shell morphology. Already, Pfenninger et al. (2003) and Albrecht et al. (2006a) observed presence of several highly divergent lineages within Ancylus. Due to the morphology of the shell our specimens agree well with Ancylus recurvus Martens (1873) and detailed description of this species given by Clessin (1882). However, assuming that our studied Ancylus belong to Ancylus sp. B sensu Albrecht et al. (2006) (= Clade 3 of Pfenninger et al. 2003), which geographically cover a wide area (from Canary Islands to Syria), according to Albrecht et al. (2006c) some available older names, such as Ancylus pileolus Fèrussac, 1822 would have priority over Ancylus recurvus. However, in Ancylus pileolus Fèrussac, 1822 the apex is inflated and bent to the left side, while the two other Ancylus species mentioned by Albrecht et al. (2006c), i.e., Ancylus rupicola Boubée, 1832, and Ancylus capuloides “Jan” Porro, 1838, have a small apex which does not reach the border of the shell’s basis, similar as it is depicted in figure of Ancylus sp. B by Albrecht et al. (2006b, Fig. 2). Considering Clessin (1882) and Westerlund (1885) the only described Ancylus sp. with a straight apex which reaches the border of the shell’s basis as the species from Montenegro, is Ancylus recurvus.

Ancylus recurvus can be easily distinguished from Ancylus fluviatilis by the shape of apex which is shifted forward reaching the border of the shell’s base (Fig. 5b). Furthermore, the apex in Ancylus recurvus is rounded and it is directed more straight, while in Ancylus fluviatilis it is acute and turned to the left side.