Valvata (Sibirovalvata) confusa WeSterlund 1897

Valvata (Sibirovalvata) confusa Westerlund, 1897

(fig. 2 E)

Regional distribution. We found two ShellS of Valvata confusa in a Sample from Terkhiyn TSagaan Nuur lake (ZhaltSanoVa collection). ThiS mountain lake iS Situated in Central Mongolia (See Appendix for coordinateS). Other localitieS of V. confusa in Mongolia are unknown. ThiS taxon, the type SpecieS of the SubgenuS Sibirovalvata StarobogatoV et Streletzkaja, 1967, iS for the firSt time recorded here from Mongolia.

Extra-limital distribution. The oVerall range of thiS SpecieS embraceS almoSt entire ASiatic RuSSia, from WeStern Siberia to Chukotka, Kamchatka, Sakhalin, and Kurile ISlandS (SitnikoVa et al. 2015). It iS known from the RuSSian partS of the Selenga and Amur RiVerS adjacent to Mongolia (SitnikoVa et al. 2015).

Morphology. The Shell of thiS SpecieS iS oVate conical with more or leSS prominent Spire and conVex almoSt Stepped whorlS (See fig. 2 E). The Shell Surface iS heaVily ribbed.