Diagnostic features of L. latens not found on M. perspicua.
# Opaque white marks on translucent whitish head and/or underside of mantle-lobes (1).
# Spire of shell does not protrude beyond outer lip of aperture so shell outline is a smooth oval when viewed in plan (see fig 31).
Features usually found on L. latens, but which sometimes occur on the widely variable M. perspicua.
# Maximum length when live 11mm (6 to 8mm frequent size). !! Young L. perspicua can be under 11mm length (see fig. 10).
# Dorsal surface smooth (2) to weakly tuberculated. !! Some M. perspicua can be also (see fig 12).
# Dorsal colours mainly whitish or sandy, often with yellow flecks near mantle edge (3) and fine black dots. !! Some L. perspicua have these markings (see fig. 10 ).
# Individuals can vary their shape between a shallow bowl, inverted saucer (4) and almost flat. !! L. perspicua though often higher, can lower itself to a shallow bowl.  Length 8mm, West Anglesey, Wales, March 2014 & length 10mm, Menai Strait, Wales, February 2011.