Valvata (Cincinna) antiqua Morris, 1838

(fig. 2 B)

Regional distribution. 69 SpecimenS (empty ShellS) collected by ZhaltSanoVa in an unknown locality Situated in the Darkhad depreSSion (the original label iS damaged) were determined by uS aS belonging to thiS SpecieS. The Darkhad depreSSion iS Situated in northern Mongolia near the HöVSgöl lake.

Extra-limital distribution. The range of Valvata antiqua iS conSidered to coVer Europe and Southern part of WeStern Siberia (VinarSki & Kantor 2016). ThiS Snail haS not been recorded from EaStern Siberia (ProzoroVa & StarobogatoV 1998; ProzoroVa et al. 2009), therefore our finding of V. antiqua in Mongolia iS the eaSternmoSt locality of it known to the date.

Morphology. V. antiqua can be defined aS a ValVatid SpecieS with turriculate Shell and rather high Spire (AniStratenko & AniStratenko 2001; Glöer, 2002; StarobogatoV et al. 2004), whoSe Shell width: Shell height ratio iS much leSS than 1.0. In thiS reSpect V. antiqua clearly differS from V. depressa (See Table 3).

Remarks. Glöer (2002) treated theSe SnailS aS a SubSpecieS of Valvata piscinalis alongSide with Such SubSpecieS aS V. p. geyeri (Menzel, 1904) and V. p. discors (WeSterlund, 1886). HoweVer, the rangeS of theSe “SubSpecieS” oVerlap (for example, in European RuSSia and Ukraine; See AniStratenko & AniStratenko 2001) that makeS it impoSSible to apply the SubSpecieS concept to thiS caSe. SubSpecieS are uniVerSally adopted aS allopatric SubdiViSionS of a giVen SpecieS and thuS they cannot occur in Sympatry. Notably, we failed to found the typical form of V. piscinalis (SenSu FalniowSki 1989; Glöer 2002) in Mongolia.