Distribution in scandinavian waters
Maximum length: 4 cm.
Appearance: Common periwinkle with cross-striped tentacles. The
pointed shell is often brown
to brown-black in colour, but sometimes can be lighter (orange - whitish).
The spires pillar, that is seen from the aperture, is usually white.
It is never pink to lilac, like most rough
periwinkles . The inside of the shell at the aperture can have dark
inward orientated lines. These
types of lines are not found in other closely related specie.
Depth: 0-15 m.
Environment: Found on both soft and hard
bottoms. The Common periwinkle lives in most shallow environments
in direct contact with e.g. sand,
and cliffs, but even crawls amongst the vegetation. This species
is not normally found in areas with excessively wave
exposed cliffs and rocks. Nor do they creep far up the beaches like
the rough periwinkle,
but the empty
shells of this species are quite often found washed up onto beaches.
Classification: The Common periwinkle is a member of
the mesogastropods under the molluscs.