Pupilla muscorum is a widespread species that occurs in almost all countries of the European Union. Its exact distribution is unknown, because parts of the literature records refer to P. pratenis rather than to P. muscorum. In Ireland, P. muscorumis in decline in most parts of its Irish range. It is now local and rare on northern coasts where it was formerly common. It has almost vanished from the southern part of the central limestone plain probably due to the 'improvement' of pastures for agriculture (Byrne et al. 2009).