''Pupilla bigranata'' is a

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

that was used for some forms of the

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

s '' Pupilla triplicata'' and ''

Pupilla muscorum ''Pupilla muscorum'', common name, commonly known as the Moss Chrysalis snail or widespread column, is a species of small air-breathing land snail, a terrestrial molluscs, terrestrial pulmonate gastropod mollusk or micromollusk in the family Pupi ...

'' (

Pupillidae Pupillidae is a family of mostly minute, air-breathing, land snails, terrestrial pulmonate gastropod mollusks or micromollusks in the superfamily Pupilloidea.MolluscaBase eds. (2021). MolluscaBase. Pupillidae W. Turton, 1831. Accessed through: ...

), but none of these forms represent a separate species, therefore such species as ''Pupilla bigranata'' does not exist.Balashov I., Neiber M., Bogon K., Hausdorf B. 2019
On the identity of "''Pupilla bigranata''" populations from Germany and Ukraine (Gastropoda: Pupillidae)
''

Archiv für Molluskenkunde ''Archiv für Molluskenkunde'' is a peer-reviewed scientific journal published by the Senckenberg Nature Research Society, covering research in malacology. Coverage ''Archiv für Molluskenkunde'' publishes original research on all aspects of mo ...

''. 148 (1): 1—7. Considering that in the original Rossmässler's description the type locality was not indicated and that type specimens are not preserved, it is not possible to determine whether ''Pupa bigranata'' Rossmässler, 1839 is synonym of '' Pupilla triplicata'' or ''

''.

References

{{Taxonbar, from=Q7260665 Pupillidae Gastropods described in 1839